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    36. Video Coding

    Vulkan implementations may expose one or more queue families supporting video coding operations. These operations are performed by recording them into a command buffer within a video coding scope, and submitting them to queues with compatible video coding capabilities.

    The Vulkan video functionalities are designed to be made available through a set of APIs built on top of each other, consisting of:

    • A core API providing common video coding functionalities,

    • APIs providing codec-independent video decode and video encode related functionalities, respectively,

    • Additional codec-specific APIs built on top of those.

    This chapter details the fundamental components and operations of these.

    36.1. Video Picture Resources

    In the context of video coding, multidimensional arrays of image data that can be used as the source or target of video coding operations are referred to as video picture resources. They may store additional metadata that includes implementation-private information used during the execution of video coding operations, as discussed later.

    Video picture resources are backed by VkImage objects. Individual subregions of VkImageView objects created from such resources can be used as decode output pictures, encode input pictures, reconstructed pictures, and/or reference pictures.

    The parameters of a video picture resource are specified using a VkVideoPictureResourceInfoKHR structure.

    The VkVideoPictureResourceInfoKHR structure is defined as:

    // Provided by VK_KHR_video_queue
typedef struct VkVideoPictureResourceInfoKHR {
    VkStructureType    sType;
    const void*        pNext;
    VkOffset2D         codedOffset;
    VkExtent2D         codedExtent;
    uint32_t           baseArrayLayer;
    VkImageView        imageViewBinding;
} VkVideoPictureResourceInfoKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • codedOffset is the offset in texels of the image subregion to use.

    • codedExtent is the size in pixels of the coded image data.

    • baseArrayLayer is the array layer of the image view specified in imageViewBinding to use as the video picture resource.

    • imageViewBinding is an image view representing the video picture resource.

    The image subresource referred to by such a structure is defined as the image array layer index specified in baseArrayLayer relative to the image subresource range the image view specified in imageViewBinding was created with.

    The meaning of the codedOffset and codedExtent depends on the command and context the video picture resource is used in, as well as on the used video profile and corresponding codec-specific semantics, as described later.

    A video picture resource is uniquely defined by the image subresource referred to by an instance of this structure, together with the codedOffset and codedExtent members that identify the image subregion within the image subresource referenced corresponding to the video picture resource according to the particular codec-specific semantics.

    Accesses to image data within a video picture resource happen at the granularity indicated by VkVideoCapabilitiesKHR::pictureAccessGranularity, as returned by vkGetPhysicalDeviceVideoCapabilitiesKHR for the used video profile. As a result, given an effective image subregion corresponding to a video picture resource, the actual image subregion accessed may be larger than that as it may include additional padding texels due to the picture access granularity. Any writes performed by video coding operations to such padding texels will result in undefined texel values.

    Two video picture resources match if they refer to the same image subresource and they specify identical codedOffset and codedExtent values.

    Valid Usage

    • VUID-VkVideoPictureResourceInfoKHR-baseArrayLayer-07175
      baseArrayLayer must be less than the VkImageViewCreateInfo::subresourceRange.layerCount specified when the image view imageViewBinding was created

    Valid Usage (Implicit)

    • VUID-VkVideoPictureResourceInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_PICTURE_RESOURCE_INFO_KHR

    • VUID-VkVideoPictureResourceInfoKHR-pNext-pNext
      pNext must be NULL

    • VUID-VkVideoPictureResourceInfoKHR-imageViewBinding-parameter
      imageViewBinding must be a valid VkImageView handle

    36.2. Decoded Picture Buffer

    An integral part of video coding pipelines is the reconstruction of pictures from a compressed video bitstream. A reconstructed picture is a video picture resource resulting from this process.

    Such reconstructed pictures can be used as reference pictures in subsequent video coding operations to provide predictions of the values of samples of subsequently decoded or encoded pictures. The correct use of such reconstructed pictures as reference pictures is driven by the video compression standard, the implementation, and the application-specific use cases.

    The list of reference pictures used to provide such predictions within a single video coding operation is referred to as the list of active reference pictures.

    The decoded picture buffer (DPB) is an indexed data structure that maintains the set of reference pictures available to be used in video coding operations. Individual indexed entries of the DPB are referred to as the decoded picture buffer (DPB) slots. The range of valid DPB slot indices is between zero and N-1, where N is the capacity of the DPB. Each DPB slot can refer to a reference picture containing a video frame or can refer to up to two reference pictures containing the top and/or bottom fields that, when both present, together represent a full video frame .

    In Vulkan, the state and the backing store of the DPB is separated as follows:

    In addition, the implementation may also maintain opaque metadata associated with DPB slots, including:

    • Reference picture metadata corresponding to the video picture resource associated with the DPB slot.

    Such metadata may be stored by the implementation as part of the DPB slot state maintained by the video session, or as part of the video picture resource backing the DPB slot.

    Any metadata stored in the video picture resources backing DPB slots are independent of the video session used to store it, hence such video picture resources can be shared with other video sessions. Correspondingly, any metadata that is dependent on the video session will always be stored as part of the DPB slot state maintained by that video session.

    The responsibility of managing the DPB is split between the application and the implementation as follows:

    In addition, the application is also responsible for managing the mapping between the codec-specific picture IDs and DPB slots, and any other codec-specific states unless otherwise specified.

    36.2.1. DPB Slot States

    At a given time, each DPB slot is either in active or inactive state. Initially, all DPB slots managed by a video session are in inactive state.

    A DPB slot can be activated by using it as the target of picture reconstruction within a video coding operation, changing its state to active.

    As part of the picture reconstruction, the implementation may also generate reference picture metadata.

    If such a video coding operation completes successfully, the activated DPB slot will have a valid picture reference and the reconstructed picture is associated with the DPB slot. This is true even if the DPB slot is used as the target of a picture reconstruction that only sets up a top field or bottom field reference picture and thus does not yet refer to a complete frame. However, if any data provided as input to such a video coding operation is not compliant to the video compression standard used, that video coding operation may complete unsuccessfully, in which case the activated DPB slot will have an invalid picture reference. This is true even if the DPB slot previously had a valid picture reference to a top field or bottom field reference picture, but the reconstruction of the other field corresponding to the DPB slot failed.

    The application can use queries to get feedback about the outcome of video coding operations and use the resulting VkQueryResultStatusKHR value to determine whether the video coding operation completed successfully (result status is positive) or unsuccessfully (result status is negative).

    Using a reference picture associated with a DPB slot that has an invalid picture reference as an active reference picture in subsequent video coding operations is legal, however, the contents of the outputs of such operations are undefined, and any DPB slots activated by such video coding operations will also have an invalid picture reference. This is true even if such video coding operations may otherwise complete successfully.

    A DPB slot can also be deactivated by the application, changing its state to inactive and invalidating any picture references and reference picture metadata associated with the DPB slot.

    A DPB slot can be activated with a new frame even if it is already active. In this case all previous associations of the DPB slots with reference pictures are replaced with an association with the reconstructed picture used to activate it. If an already active DPB slot is activated with a reconstructed field picture, then the behavior is as follows:

    • If the DPB slot is currently associated with a frame, then that association is replaced with an association with the reconstructed field picture used to activate it.

    • If the DPB slot is not currently associated with a top field picture and the DPB slot is activated with a top field picture, or if the DPB slot is not currently associated with a bottom field picture and the DPB slot is activated with a bottom field picture, then the DPB slot is associated with the reconstructed field picture used to activate it, without disturbing the other field picture association, if any.

    • If the DPB slot is currently associated with a top field picture and the DPB slot is activated with a new top field picture, or if the DPB slot is currently associated with a bottom field picture and the DPB slot is activated with a new bottom field picture, then that association is replaced with an association with the reconstructed field picture used to activate it, without disturbing the other field picture association, if any.

    36.3. Video Profiles

    The VkVideoProfileInfoKHR structure is defined as follows:

    // Provided by VK_KHR_video_queue
typedef struct VkVideoProfileInfoKHR {
    VkStructureType                     sType;
    const void*                         pNext;
    VkVideoCodecOperationFlagBitsKHR    videoCodecOperation;
    VkVideoChromaSubsamplingFlagsKHR    chromaSubsampling;
    VkVideoComponentBitDepthFlagsKHR    lumaBitDepth;
    VkVideoComponentBitDepthFlagsKHR    chromaBitDepth;
} VkVideoProfileInfoKHR;

    Video profiles are provided as input to video capability queries such as vkGetPhysicalDeviceVideoCapabilitiesKHR or vkGetPhysicalDeviceVideoFormatPropertiesKHR, as well as when creating resources to be used by video coding operations such as images, buffers, query pools, and video sessions.

    The full description of a video profile is specified by an instance of this structure, and the codec-specific and auxiliary structures provided in its pNext chain.

    When this structure is specified as an input parameter to vkGetPhysicalDeviceVideoCapabilitiesKHR, or through the pProfiles member of an VkVideoProfileListInfoKHR structure in the pNext chain of the input parameter of a query command such as vkGetPhysicalDeviceVideoFormatPropertiesKHR or vkGetPhysicalDeviceImageFormatProperties2, the following error codes indicate specific causes of the failure of the query operation:

    • VK_ERROR_VIDEO_PICTURE_LAYOUT_NOT_SUPPORTED_KHR indicates that the requested video picture layout (e.g. through the pictureLayout member of a VkVideoDecodeH264ProfileInfoKHR structure included in the pNext chain of VkVideoProfileInfoKHR) is not supported.

    • VK_ERROR_VIDEO_PROFILE_OPERATION_NOT_SUPPORTED_KHR indicates that a video profile operation specified by videoCodecOperation is not supported.

    • VK_ERROR_VIDEO_PROFILE_FORMAT_NOT_SUPPORTED_KHR indicates that video format parameters specified by chromaSubsampling, lumaBitDepth, or chromaBitDepth are not supported.

    • VK_ERROR_VIDEO_PROFILE_CODEC_NOT_SUPPORTED_KHR indicates that the codec-specific parameters corresponding to the video codec operation are not supported.

    Valid Usage

    • VUID-VkVideoProfileInfoKHR-chromaSubsampling-07013
      chromaSubsampling must have a single bit set

    • VUID-VkVideoProfileInfoKHR-lumaBitDepth-07014
      lumaBitDepth must have a single bit set

    • VUID-VkVideoProfileInfoKHR-chromaSubsampling-07015
      If chromaSubsampling is not VK_VIDEO_CHROMA_SUBSAMPLING_MONOCHROME_BIT_KHR, then chromaBitDepth must have a single bit set

    • VUID-VkVideoProfileInfoKHR-videoCodecOperation-07179
      If videoCodecOperation is VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR, then the pNext chain must include a VkVideoDecodeH264ProfileInfoKHR structure

    • VUID-VkVideoProfileInfoKHR-videoCodecOperation-07180
      If videoCodecOperation is VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR, then the pNext chain must include a VkVideoDecodeH265ProfileInfoKHR structure

    Valid Usage (Implicit)

    • VUID-VkVideoProfileInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_PROFILE_INFO_KHR

    • VUID-VkVideoProfileInfoKHR-videoCodecOperation-parameter
      videoCodecOperation must be a valid VkVideoCodecOperationFlagBitsKHR value

    • VUID-VkVideoProfileInfoKHR-chromaSubsampling-parameter
      chromaSubsampling must be a valid combination of VkVideoChromaSubsamplingFlagBitsKHR values

    • VUID-VkVideoProfileInfoKHR-chromaSubsampling-requiredbitmask
      chromaSubsampling must not be 0

    • VUID-VkVideoProfileInfoKHR-lumaBitDepth-parameter
      lumaBitDepth must be a valid combination of VkVideoComponentBitDepthFlagBitsKHR values

    • VUID-VkVideoProfileInfoKHR-lumaBitDepth-requiredbitmask
      lumaBitDepth must not be 0

    • VUID-VkVideoProfileInfoKHR-chromaBitDepth-parameter
      chromaBitDepth must be a valid combination of VkVideoComponentBitDepthFlagBitsKHR values

    Possible values of VkVideoProfileInfoKHR::videoCodecOperation, specifying the type of video coding operation and video compression standard used by a video profile, are:

    // Provided by VK_KHR_video_queue
typedef enum VkVideoCodecOperationFlagBitsKHR {
    VK_VIDEO_CODEC_OPERATION_NONE_KHR = 0,
  // Provided by VK_KHR_video_decode_h264
    VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR = 0x00000001,
  // Provided by VK_KHR_video_decode_h265
    VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR = 0x00000002,
} VkVideoCodecOperationFlagBitsKHR;

    • VK_VIDEO_CODEC_OPERATION_NONE_KHR indicates no support for any video codec operations.

    • VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR specifies support for H.264 video decode operations.

    • VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR specifies support for H.265 video decode operations.

    // Provided by VK_KHR_video_queue
typedef VkFlags VkVideoCodecOperationFlagsKHR;

    VkVideoCodecOperationFlagsKHR is a bitmask type for setting a mask of zero or more VkVideoCodecOperationFlagBitsKHR.

    The video format chroma subsampling is defined with the following enums:

    // Provided by VK_KHR_video_queue
typedef enum VkVideoChromaSubsamplingFlagBitsKHR {
    VK_VIDEO_CHROMA_SUBSAMPLING_INVALID_KHR = 0,
    VK_VIDEO_CHROMA_SUBSAMPLING_MONOCHROME_BIT_KHR = 0x00000001,
    VK_VIDEO_CHROMA_SUBSAMPLING_420_BIT_KHR = 0x00000002,
    VK_VIDEO_CHROMA_SUBSAMPLING_422_BIT_KHR = 0x00000004,
    VK_VIDEO_CHROMA_SUBSAMPLING_444_BIT_KHR = 0x00000008,
} VkVideoChromaSubsamplingFlagBitsKHR;

    • VK_VIDEO_CHROMA_SUBSAMPLING_MONOCHROME_BIT_KHR specifies that the format is monochrome.

    • VK_VIDEO_CHROMA_SUBSAMPLING_420_BIT_KHR specified that the format is 4:2:0 chroma subsampled, i.e. the two chroma components are sampled horizontally and vertically at half the sample rate of the luma component.

    • VK_VIDEO_CHROMA_SUBSAMPLING_422_BIT_KHR - the format is 4:2:2 chroma subsampled, i.e. the two chroma components are sampled horizontally at half the sample rate of luma component.

    • VK_VIDEO_CHROMA_SUBSAMPLING_444_BIT_KHR - the format is 4:4:4 chroma sampled, i.e. all three components of the Y′CBCR format are sampled at the same rate, thus there is no chroma subsampling.

    Chroma subsampling is described in more detail in the Chroma Reconstruction section.

    // Provided by VK_KHR_video_queue
typedef VkFlags VkVideoChromaSubsamplingFlagsKHR;

    VkVideoChromaSubsamplingFlagsKHR is a bitmask type for setting a mask of zero or more VkVideoChromaSubsamplingFlagBitsKHR.

    Possible values for the video format component bit depth are:

    // Provided by VK_KHR_video_queue
typedef enum VkVideoComponentBitDepthFlagBitsKHR {
    VK_VIDEO_COMPONENT_BIT_DEPTH_INVALID_KHR = 0,
    VK_VIDEO_COMPONENT_BIT_DEPTH_8_BIT_KHR = 0x00000001,
    VK_VIDEO_COMPONENT_BIT_DEPTH_10_BIT_KHR = 0x00000004,
    VK_VIDEO_COMPONENT_BIT_DEPTH_12_BIT_KHR = 0x00000010,
} VkVideoComponentBitDepthFlagBitsKHR;

    • VK_VIDEO_COMPONENT_BIT_DEPTH_8_BIT_KHR specifies a component bit depth of 8 bits.

    • VK_VIDEO_COMPONENT_BIT_DEPTH_10_BIT_KHR specifies a component bit depth of 10 bits.

    • VK_VIDEO_COMPONENT_BIT_DEPTH_12_BIT_KHR specifies a component bit depth of 12 bits.

    // Provided by VK_KHR_video_queue
typedef VkFlags VkVideoComponentBitDepthFlagsKHR;

    VkVideoComponentBitDepthFlagsKHR is a bitmask type for setting a mask of zero or more VkVideoComponentBitDepthFlagBitsKHR.

    Additional information about the video decode use case can be provided by adding a VkVideoDecodeUsageInfoKHR structure to the pNext chain of VkVideoProfileInfoKHR.

    The VkVideoDecodeUsageInfoKHR structure is defined as:

    // Provided by VK_KHR_video_decode_queue
typedef struct VkVideoDecodeUsageInfoKHR {
    VkStructureType               sType;
    const void*                   pNext;
    VkVideoDecodeUsageFlagsKHR    videoUsageHints;
} VkVideoDecodeUsageInfoKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • videoUsageHints is a bitmask of VkVideoDecodeUsageFlagBitsKHR specifying hints about the intended use of the video decode profile.

    Valid Usage (Implicit)

    • VUID-VkVideoDecodeUsageInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_DECODE_USAGE_INFO_KHR

    • VUID-VkVideoDecodeUsageInfoKHR-videoUsageHints-parameter
      videoUsageHints must be a valid combination of VkVideoDecodeUsageFlagBitsKHR values

    The following bits can be specified in VkVideoDecodeUsageInfoKHR::videoUsageHints as a hint about the video decode use case:

    // Provided by VK_KHR_video_decode_queue
typedef enum VkVideoDecodeUsageFlagBitsKHR {
    VK_VIDEO_DECODE_USAGE_DEFAULT_KHR = 0,
    VK_VIDEO_DECODE_USAGE_TRANSCODING_BIT_KHR = 0x00000001,
    VK_VIDEO_DECODE_USAGE_OFFLINE_BIT_KHR = 0x00000002,
    VK_VIDEO_DECODE_USAGE_STREAMING_BIT_KHR = 0x00000004,
} VkVideoDecodeUsageFlagBitsKHR;

    • VK_VIDEO_DECODE_USAGE_TRANSCODING_BIT_KHR specifies that video decoding is intended to be used in conjunction with video encoding to transcode a video bitstream with the same and/or different codecs.

    • VK_VIDEO_DECODE_USAGE_OFFLINE_BIT_KHR specifies that video decoding is intended to be used to consume a local video bitstream.

    • VK_VIDEO_DECODE_USAGE_STREAMING_BIT_KHR specifies that video decoding is intended to be used to consume a video bitstream received as a continuous flow over network.

    Note

    There are no restrictions on the combination of bits that can be specified by the application. However, applications should use reasonable combinations in order for the implementation to be able to select the most appropriate mode of operation for the particular use case.

    		 
    // Provided by VK_KHR_video_decode_queue
typedef VkFlags VkVideoDecodeUsageFlagsKHR;

    VkVideoDecodeUsageFlagsKHR is a bitmask type for setting a mask of zero or more VkVideoDecodeUsageFlagBitsKHR.

    Additional information about the video encode use case can be provided by adding a VkVideoEncodeUsageInfoKHR structure to the pNext chain of VkVideoProfileInfoKHR.

    The VkVideoEncodeUsageInfoKHR structure is defined as:

    // Provided by VK_KHR_video_encode_queue
typedef struct VkVideoEncodeUsageInfoKHR {
    VkStructureType                 sType;
    const void*                     pNext;
    VkVideoEncodeUsageFlagsKHR      videoUsageHints;
    VkVideoEncodeContentFlagsKHR    videoContentHints;
    VkVideoEncodeTuningModeKHR      tuningMode;
} VkVideoEncodeUsageInfoKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • videoUsageHints is a bitmask of VkVideoEncodeUsageFlagBitsKHR specifying hints about the intended use of the video encode profile.

    • videoContentHints is a bitmask of VkVideoEncodeContentFlagBitsKHR specifying hints about the content to be encoded using the video encode profile.

    • tuningMode is a VkVideoEncodeTuningModeKHR value specifying the tuning mode to use when encoding with the video profile.

    Valid Usage (Implicit)

    • VUID-VkVideoEncodeUsageInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_ENCODE_USAGE_INFO_KHR

    • VUID-VkVideoEncodeUsageInfoKHR-videoUsageHints-parameter
      videoUsageHints must be a valid combination of VkVideoEncodeUsageFlagBitsKHR values

    • VUID-VkVideoEncodeUsageInfoKHR-videoContentHints-parameter
      videoContentHints must be a valid combination of VkVideoEncodeContentFlagBitsKHR values

    • VUID-VkVideoEncodeUsageInfoKHR-tuningMode-parameter
      If tuningMode is not 0, tuningMode must be a valid VkVideoEncodeTuningModeKHR value

    The following bits can be specified in VkVideoEncodeUsageInfoKHR::videoUsageHints as a hint about the video encode use case:

    // Provided by VK_KHR_video_encode_queue
typedef enum VkVideoEncodeUsageFlagBitsKHR {
    VK_VIDEO_ENCODE_USAGE_DEFAULT_KHR = 0,
    VK_VIDEO_ENCODE_USAGE_TRANSCODING_BIT_KHR = 0x00000001,
    VK_VIDEO_ENCODE_USAGE_STREAMING_BIT_KHR = 0x00000002,
    VK_VIDEO_ENCODE_USAGE_RECORDING_BIT_KHR = 0x00000004,
    VK_VIDEO_ENCODE_USAGE_CONFERENCING_BIT_KHR = 0x00000008,
} VkVideoEncodeUsageFlagBitsKHR;

    • VK_VIDEO_ENCODE_USAGE_TRANSCODING_BIT_KHR specifies that video encoding is intended to be used in conjunction with video decoding to transcode a video bitstream with the same and/or different codecs.

    • VK_VIDEO_ENCODE_USAGE_STREAMING_BIT_KHR specifies that video encoding is intended to be used to produce a video bitstream that is expected to be sent as a continuous flow over network.

    • VK_VIDEO_ENCODE_USAGE_RECORDING_BIT_KHR specifies that video encoding is intended to be used for real-time recording for offline consumption.

    • VK_VIDEO_ENCODE_USAGE_CONFERENCING_BIT_KHR specifies that video encoding is intended to be used in a video conferencing scenario.

    Note

    There are no restrictions on the combination of bits that can be specified by the application. However, applications should use reasonable combinations in order for the implementation to be able to select the most appropriate mode of operation for the particular use case.

    		 
    // Provided by VK_KHR_video_encode_queue
typedef VkFlags VkVideoEncodeUsageFlagsKHR;

    VkVideoEncodeUsageFlagsKHR is a bitmask type for setting a mask of zero or more VkVideoEncodeUsageFlagBitsKHR.

    The following bits can be specified in VkVideoEncodeUsageInfoKHR::videoContentHints as a hint about the encoded video content:

    // Provided by VK_KHR_video_encode_queue
typedef enum VkVideoEncodeContentFlagBitsKHR {
    VK_VIDEO_ENCODE_CONTENT_DEFAULT_KHR = 0,
    VK_VIDEO_ENCODE_CONTENT_CAMERA_BIT_KHR = 0x00000001,
    VK_VIDEO_ENCODE_CONTENT_DESKTOP_BIT_KHR = 0x00000002,
    VK_VIDEO_ENCODE_CONTENT_RENDERED_BIT_KHR = 0x00000004,
} VkVideoEncodeContentFlagBitsKHR;

    • VK_VIDEO_ENCODE_CONTENT_CAMERA_BIT_KHR specifies that video encoding is intended to be used to encode camera content.

    • VK_VIDEO_ENCODE_CONTENT_DESKTOP_BIT_KHR specifies that video encoding is intended to be used to encode desktop content.

    • VK_VIDEO_ENCODE_CONTENT_RENDERED_BIT_KHR specified that video encoding is intended to be used to encode rendered (e.g. game) content.

    Note

    There are no restrictions on the combination of bits that can be specified by the application. However, applications should use reasonable combinations in order for the implementation to be able to select the most appropriate mode of operation for the particular content type.

    		 
    // Provided by VK_KHR_video_encode_queue
typedef VkFlags VkVideoEncodeContentFlagsKHR;

    VkVideoEncodeContentFlagsKHR is a bitmask type for setting a mask of zero or more VkVideoEncodeContentFlagBitsKHR.

    Possible video encode tuning mode values are as follows:

    // Provided by VK_KHR_video_encode_queue
typedef enum VkVideoEncodeTuningModeKHR {
    VK_VIDEO_ENCODE_TUNING_MODE_DEFAULT_KHR = 0,
    VK_VIDEO_ENCODE_TUNING_MODE_HIGH_QUALITY_KHR = 1,
    VK_VIDEO_ENCODE_TUNING_MODE_LOW_LATENCY_KHR = 2,
    VK_VIDEO_ENCODE_TUNING_MODE_ULTRA_LOW_LATENCY_KHR = 3,
    VK_VIDEO_ENCODE_TUNING_MODE_LOSSLESS_KHR = 4,
} VkVideoEncodeTuningModeKHR;

    • VK_VIDEO_ENCODE_TUNING_MODE_DEFAULT_KHR specifies the default tuning mode.

    • VK_VIDEO_ENCODE_TUNING_MODE_HIGH_QUALITY_KHR specifies that video encoding is tuned for high quality. When using this tuning mode, the implementation may compromise the latency of video encoding operations to improve quality.

    • VK_VIDEO_ENCODE_TUNING_MODE_LOW_LATENCY_KHR specifies that video encoding is tuned for low latency. When using this tuning mode, the implementation may compromise quality to increase the performance and lower the latency of video encode operations.

    • VK_VIDEO_ENCODE_TUNING_MODE_ULTRA_LOW_LATENCY_KHR specifies that video encoding is tuned for ultra-low latency. When using this tuning mode, the implementation may compromise quality to maximize the performance and minimize the latency of video encoding operations.

    • VK_VIDEO_ENCODE_TUNING_MODE_LOSSLESS_KHR specifies that video encoding is tuned for lossless encoding. When using this tuning mode, video encode operations produce lossless output.

    The VkVideoProfileListInfoKHR structure is defined as:

    // Provided by VK_KHR_video_queue
typedef struct VkVideoProfileListInfoKHR {
    VkStructureType                 sType;
    const void*                     pNext;
    uint32_t                        profileCount;
    const VkVideoProfileInfoKHR*    pProfiles;
} VkVideoProfileListInfoKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • profileCount is the number of elements in the pProfiles array.

    • pProfiles is a pointer to an array of VkVideoProfileInfoKHR structures.

    Note:

    Video transcoding is an example of a use case that necessitates the specification of multiple profiles in various contexts.

    When the application provides a video decode profile and one or more video encode profiles in the profile list, the implementation ensures that any capabilitities returned or resources created are suitable for the video transcoding use cases without the need for manual data transformations.

    Valid Usage

    • VUID-VkVideoProfileListInfoKHR-pProfiles-06813
      pProfiles must not contain more than one element whose videoCodecOperation member specifies a decode operation

    Valid Usage (Implicit)

    • VUID-VkVideoProfileListInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_PROFILE_LIST_INFO_KHR

    • VUID-VkVideoProfileListInfoKHR-pProfiles-parameter
      If profileCount is not 0, pProfiles must be a valid pointer to an array of profileCount valid VkVideoProfileInfoKHR structures

    36.4. Video Capabilities

    36.4.1. Video Coding Capabilities

    To query video coding capabilities for a specific video profile, call:

    // Provided by VK_KHR_video_queue
VkResult vkGetPhysicalDeviceVideoCapabilitiesKHR(
    VkPhysicalDevice                            physicalDevice,
    const VkVideoProfileInfoKHR*                pVideoProfile,
    VkVideoCapabilitiesKHR*                     pCapabilities);

    • physicalDevice is the physical device from which to query the video decode or encode capabilities.

    • pVideoProfile is a pointer to a VkVideoProfileInfoKHR structure.

    • pCapabilities is a pointer to a VkVideoCapabilitiesKHR structure in which the capabilities are returned.

    If the video profile described by pVideoProfile is supported by the implementation, then this command returns VK_SUCCESS and pCapabilities is filled with the capabilities supported with the specified video profile. Otherwise, one of the video-profile-specific error codes are returned.

    Valid Usage

    • VUID-vkGetPhysicalDeviceVideoCapabilitiesKHR-pVideoProfile-07183
      If pVideoProfile->videoCodecOperation specifies a decode operation, then the pNext chain of pCapabilities must include a VkVideoDecodeCapabilitiesKHR structure

    • VUID-vkGetPhysicalDeviceVideoCapabilitiesKHR-pVideoProfile-07184
      If pVideoProfile->videoCodecOperation is VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR, then the pNext chain of pCapabilities must include a VkVideoDecodeH264CapabilitiesKHR structure

    • VUID-vkGetPhysicalDeviceVideoCapabilitiesKHR-pVideoProfile-07185
      If pVideoProfile->videoCodecOperation is VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR, then the pNext chain of pCapabilities must include a VkVideoDecodeH265CapabilitiesKHR structure

    • VUID-vkGetPhysicalDeviceVideoCapabilitiesKHR-pVideoProfile-07186
      If pVideoProfile->videoCodecOperation specifies an encode operation, then the pNext chain of pCapabilities must include a VkVideoEncodeCapabilitiesKHR structure

    Valid Usage (Implicit)

    • VUID-vkGetPhysicalDeviceVideoCapabilitiesKHR-physicalDevice-parameter
      physicalDevice must be a valid VkPhysicalDevice handle

    • VUID-vkGetPhysicalDeviceVideoCapabilitiesKHR-pVideoProfile-parameter
      pVideoProfile must be a valid pointer to a valid VkVideoProfileInfoKHR structure

    • VUID-vkGetPhysicalDeviceVideoCapabilitiesKHR-pCapabilities-parameter
      pCapabilities must be a valid pointer to a VkVideoCapabilitiesKHR structure

    Return Codes
    Success

    • VK_SUCCESS

    Failure

    • VK_ERROR_OUT_OF_HOST_MEMORY

    • VK_ERROR_OUT_OF_DEVICE_MEMORY

    • VK_ERROR_VIDEO_PROFILE_OPERATION_NOT_SUPPORTED_KHR

    • VK_ERROR_VIDEO_PROFILE_FORMAT_NOT_SUPPORTED_KHR

    • VK_ERROR_VIDEO_PICTURE_LAYOUT_NOT_SUPPORTED_KHR

    • VK_ERROR_VIDEO_PROFILE_CODEC_NOT_SUPPORTED_KHR

    The VkVideoCapabilitiesKHR structure is defined as:

    // Provided by VK_KHR_video_queue
typedef struct VkVideoCapabilitiesKHR {
    VkStructureType              sType;
    void*                        pNext;
    VkVideoCapabilityFlagsKHR    flags;
    VkDeviceSize                 minBitstreamBufferOffsetAlignment;
    VkDeviceSize                 minBitstreamBufferSizeAlignment;
    VkExtent2D                   pictureAccessGranularity;
    VkExtent2D                   minCodedExtent;
    VkExtent2D                   maxCodedExtent;
    uint32_t                     maxDpbSlots;
    uint32_t                     maxActiveReferencePictures;
    VkExtensionProperties        stdHeaderVersion;
} VkVideoCapabilitiesKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • flags is a bitmask of VkVideoCapabilityFlagBitsKHR specifying capability flags.

    • minBitstreamBufferOffsetAlignment is the minimum alignment for bitstream buffer offsets.

    • minBitstreamBufferSizeAlignment is the minimum alignment for bitstream buffer range sizes.

    • pictureAccessGranularity is the granularity at which image access to video picture resources happen.

    • minCodedExtent is the minimum width and height of the coded frames.

    • maxCodedExtent is the maximum width and height of the coded frames.

    • maxDpbSlots is the maximum number of DPB slots supported by a single video session.

    • maxActiveReferencePictures is the maximum number of active reference pictures a single video coding operation can use.

    • stdHeaderVersion is a VkExtensionProperties structure reporting the Video Std header name and version supported for the video profile.

    Note:

    It is common for video compression standards to allow using all reference pictures associated with active DPB slots as active reference pictures, hence for video decode profiles the values returned in maxDpbSlots and maxActiveReferencePictures are often equal. Similarly, in case of video decode profiles supporting field pictures the value of maxActiveReferencePictures often equals maxDpbSlots × 2.
    Valid Usage (Implicit)

    Bits which can be set in VkVideoCapabilitiesKHR::flags are:

    // Provided by VK_KHR_video_queue
typedef enum VkVideoCapabilityFlagBitsKHR {
    VK_VIDEO_CAPABILITY_PROTECTED_CONTENT_BIT_KHR = 0x00000001,
    VK_VIDEO_CAPABILITY_SEPARATE_REFERENCE_IMAGES_BIT_KHR = 0x00000002,
} VkVideoCapabilityFlagBitsKHR;

    • VK_VIDEO_CAPABILITY_PROTECTED_CONTENT_BIT_KHR specifies that video sessions support producing and consuming protected content.

    • VK_VIDEO_CAPABILITY_SEPARATE_REFERENCE_IMAGES_BIT_KHR specifies that the video picture resources associated with the DPB slots of a video session can be backed by separate VkImage objects. If this capability flag is not present, then all DPB slots of a video session must be associated with video picture resources backed by the same VkImage object (e.g. using different layers of the same image).

    // Provided by VK_KHR_video_queue
typedef VkFlags VkVideoCapabilityFlagsKHR;

    VkVideoCapabilityFlagsKHR is a bitmask type for setting a mask of zero or more VkVideoCapabilityFlagBitsKHR.

    36.4.2. Video Format Capabilities

    To enumerate the supported output, input and DPB image formats and corresponding capabilities for a specific video profile, call:

    // Provided by VK_KHR_video_queue
VkResult vkGetPhysicalDeviceVideoFormatPropertiesKHR(
    VkPhysicalDevice                            physicalDevice,
    const VkPhysicalDeviceVideoFormatInfoKHR*   pVideoFormatInfo,
    uint32_t*                                   pVideoFormatPropertyCount,
    VkVideoFormatPropertiesKHR*                 pVideoFormatProperties);

    • physicalDevice is the physical device from which to query the video format properties.

    • pVideoFormatInfo is a pointer to a VkPhysicalDeviceVideoFormatInfoKHR structure specifying the usage and video profiles for which supported image formats and capabilities are returned.

    • pVideoFormatPropertyCount is a pointer to an integer related to the number of video format properties available or queried, as described below.

    • pVideoFormatProperties is a pointer to an array of VkVideoFormatPropertiesKHR structures in which supported image formats and capabilities are returned.

    If pVideoFormatProperties is NULL, then the number of video format properties supported for the given physicalDevice is returned in pVideoFormatPropertyCount. Otherwise, pVideoFormatPropertyCount must point to a variable set by the user to the number of elements in the pVideoFormatProperties array, and on return the variable is overwritten with the number of values actually written to pVideoFormatProperties. If the value of pVideoFormatPropertyCount is less than the number of video format properties supported, at most pVideoFormatPropertyCount values will be written to pVideoFormatProperties, and VK_INCOMPLETE will be returned instead of VK_SUCCESS, to indicate that not all the available values were returned.

    Video format properties are always queried with respect to a specific set of video profiles. These are specified by chaining the VkVideoProfileListInfoKHR structure to pVideoFormatInfo.

    For most use cases, the images are used by a single video session and a single video profile is provided. For a use case such as video transcoding, where a decode session output image can be used as encode input in one or more encode sessions, multiple video profiles corresponding to the video sessions that will share the image must be provided.

    If any of the video profiles specified via VkVideoProfileListInfoKHR::pProfiles are not supported, then this command returns one of the video-profile-specific error codes. Furthermore, if VkPhysicalDeviceVideoFormatInfoKHR::imageUsage includes any image usage flags not supported by the specified video profiles, then this command returns VK_ERROR_IMAGE_USAGE_NOT_SUPPORTED_KHR.

    This command also returns VK_ERROR_IMAGE_USAGE_NOT_SUPPORTED_KHR if VkPhysicalDeviceVideoFormatInfoKHR::imageUsage does not include the appropriate flags as dictated by the decode capability flags returned in VkVideoDecodeCapabilitiesKHR::flags for any of the profiles specified in the VkVideoProfileListInfoKHR structure provided in the pNext chain of pVideoFormatInfo.

    If the decode capability flags include VK_VIDEO_DECODE_CAPABILITY_DPB_AND_OUTPUT_COINCIDE_BIT_KHR but not VK_VIDEO_DECODE_CAPABILITY_DPB_AND_OUTPUT_DISTINCT_BIT_KHR, then in order to query video format properties for decode DPB and output usage, VkPhysicalDeviceVideoFormatInfoKHR::imageUsage must include both VK_IMAGE_USAGE_VIDEO_DECODE_DPB_BIT_KHR and VK_IMAGE_USAGE_VIDEO_DECODE_DST_BIT_KHR. Otherwise, the call will fail with VK_ERROR_IMAGE_USAGE_NOT_SUPPORTED_KHR.

    If the decode capability flags include VK_VIDEO_DECODE_CAPABILITY_DPB_AND_OUTPUT_DISTINCT_BIT_KHR but not VK_VIDEO_DECODE_CAPABILITY_DPB_AND_OUTPUT_COINCIDE_BIT_KHR, then in order to query video format properties for decode DPB usage, VkPhysicalDeviceVideoFormatInfoKHR::imageUsage must include VK_IMAGE_USAGE_VIDEO_DECODE_DPB_BIT_KHR, but not VK_IMAGE_USAGE_VIDEO_DECODE_DST_BIT_KHR. Otherwise, the call will fail with VK_ERROR_IMAGE_USAGE_NOT_SUPPORTED_KHR. Similarly, to query video format properties for decode output usage, VkPhysicalDeviceVideoFormatInfoKHR::imageUsage must include VK_IMAGE_USAGE_VIDEO_DECODE_DST_BIT_KHR, but not VK_IMAGE_USAGE_VIDEO_DECODE_DPB_BIT_KHR. Otherwise, the call will fail with VK_ERROR_IMAGE_USAGE_NOT_SUPPORTED_KHR.

    The imageUsage member of the VkPhysicalDeviceVideoFormatInfoKHR structure specifies the expected video usage flags that the returned video formats must support. Correspondingly, the imageUsageFlags member of each VkVideoFormatPropertiesKHR structure returned will contain at least the same set of image usage flags.

    If the implementation supports using video input, output, or DPB images of a particular format in operations other than video decode/encode then the imageUsageFlags member of the corresponding VkVideoFormatPropertiesKHR structure returned will include additional image usage flags indicating that.

    Note:

    For most use cases, only decode or encode related usage flags are going to be specified. For a use case such as transcode, if the image were to be shared between decode and encode session(s), then both decode and encode related usage flags can be set.

    Multiple VkVideoFormatPropertiesKHR entries may be returned with the same format member with different componentMapping, imageType, or imageTiling values, as described later.

    In addition, a different set of VkVideoFormatPropertiesKHR entries may be returned depending on the imageUsage member of the VkPhysicalDeviceVideoFormatInfoKHR structure, even for the same set of video profiles, for example, based on whether encode input, encode DPB, decode output, and/or decode DPB usage is requested.

    The application can select the parameters returned in the VkVideoFormatPropertiesKHR entries and use compatible parameters when creating the input, output, and DPB images. The implementation will report all image creation and usage flags that are valid for images used with the requested video profiles but applications should create images only with those that are necessary for the particular use case.

    Before creating an image, the application can obtain the complete set of supported image format features by calling vkGetPhysicalDeviceImageFormatProperties2 using parameters derived from the members of one of the reported VkVideoFormatPropertiesKHR entries and adding the same VkVideoProfileListInfoKHR structure to the pNext chain of VkPhysicalDeviceImageFormatInfo2.

    The componentMapping member of VkVideoFormatPropertiesKHR defines the ordering of the Y′CBCR color channels from the perspective of the video codec operations specified in VkVideoProfileListInfoKHR. For example, if the implementation produces video decode output with the format VK_FORMAT_G8_B8R8_2PLANE_420_UNORM where the blue and red chrominance channels are swapped then the componentMapping member of the corresponding VkVideoFormatPropertiesKHR structure will have the following member values:

    components.r = VK_COMPONENT_SWIZZLE_B;        // Cb component
components.g = VK_COMPONENT_SWIZZLE_IDENTITY; // Y component
components.b = VK_COMPONENT_SWIZZLE_R;        // Cr component
components.a = VK_COMPONENT_SWIZZLE_IDENTITY; // unused, defaults to 1.0
    Valid Usage

    • VUID-vkGetPhysicalDeviceVideoFormatPropertiesKHR-pNext-06812
      The pNext chain of pVideoFormatInfo must include a VkVideoProfileListInfoKHR structure with profileCount greater than 0

    Valid Usage (Implicit)

    • VUID-vkGetPhysicalDeviceVideoFormatPropertiesKHR-physicalDevice-parameter
      physicalDevice must be a valid VkPhysicalDevice handle

    • VUID-vkGetPhysicalDeviceVideoFormatPropertiesKHR-pVideoFormatInfo-parameter
      pVideoFormatInfo must be a valid pointer to a valid VkPhysicalDeviceVideoFormatInfoKHR structure

    • VUID-vkGetPhysicalDeviceVideoFormatPropertiesKHR-pVideoFormatPropertyCount-parameter
      pVideoFormatPropertyCount must be a valid pointer to a uint32_t value

    • VUID-vkGetPhysicalDeviceVideoFormatPropertiesKHR-pVideoFormatProperties-parameter
      If the value referenced by pVideoFormatPropertyCount is not 0, and pVideoFormatProperties is not NULL, pVideoFormatProperties must be a valid pointer to an array of pVideoFormatPropertyCount VkVideoFormatPropertiesKHR structures

    Return Codes
    Success

    • VK_SUCCESS

    • VK_INCOMPLETE

    Failure

    • VK_ERROR_OUT_OF_HOST_MEMORY

    • VK_ERROR_OUT_OF_DEVICE_MEMORY

    • VK_ERROR_IMAGE_USAGE_NOT_SUPPORTED_KHR

    • VK_ERROR_VIDEO_PROFILE_OPERATION_NOT_SUPPORTED_KHR

    • VK_ERROR_VIDEO_PROFILE_FORMAT_NOT_SUPPORTED_KHR

    • VK_ERROR_VIDEO_PICTURE_LAYOUT_NOT_SUPPORTED_KHR

    • VK_ERROR_VIDEO_PROFILE_CODEC_NOT_SUPPORTED_KHR

    The VkPhysicalDeviceVideoFormatInfoKHR structure is defined as:

    // Provided by VK_KHR_video_queue
typedef struct VkPhysicalDeviceVideoFormatInfoKHR {
    VkStructureType      sType;
    const void*          pNext;
    VkImageUsageFlags    imageUsage;
} VkPhysicalDeviceVideoFormatInfoKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • imageUsage is a bitmask of VkImageUsageFlagBits specifying the intended usage of the video images.

    Valid Usage (Implicit)

    • VUID-VkPhysicalDeviceVideoFormatInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_VIDEO_FORMAT_INFO_KHR

    • VUID-VkPhysicalDeviceVideoFormatInfoKHR-pNext-pNext
      pNext must be NULL or a pointer to a valid instance of VkVideoProfileListInfoKHR

    • VUID-VkPhysicalDeviceVideoFormatInfoKHR-sType-unique
      The sType value of each struct in the pNext chain must be unique

    • VUID-VkPhysicalDeviceVideoFormatInfoKHR-imageUsage-parameter
      imageUsage must be a valid combination of VkImageUsageFlagBits values

    • VUID-VkPhysicalDeviceVideoFormatInfoKHR-imageUsage-requiredbitmask
      imageUsage must not be 0

    The VkVideoFormatPropertiesKHR structure is defined as:

    // Provided by VK_KHR_video_queue
typedef struct VkVideoFormatPropertiesKHR {
    VkStructureType       sType;
    void*                 pNext;
    VkFormat              format;
    VkComponentMapping    componentMapping;
    VkImageCreateFlags    imageCreateFlags;
    VkImageType           imageType;
    VkImageTiling         imageTiling;
    VkImageUsageFlags     imageUsageFlags;
} VkVideoFormatPropertiesKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • format is a VkFormat that specifies the format that can be used with the specified video profiles and image usages.

    • componentMapping defines the color channel order used for the format. format along with componentMapping describe how the color channels are ordered when producing video decoder output or are expected to be ordered in video encoder input, when applicable. If the format reported does not require component swizzling then all members of componentMapping will be set to VK_COMPONENT_SWIZZLE_IDENTITY.

    • imageCreateFlags is a bitmask of VkImageCreateFlagBits specifying the supported image creation flags for the format.

    • imageType is a VkImageType that specifies the image type the format can be used with.

    • imageTiling is a VkImageTiling that specifies the image tiling the format can be used with.

    • imageUsageFlags is a bitmask of VkImageUsageFlagBits specifying the supported image usage flags for the format.

    Valid Usage (Implicit)

    • VUID-VkVideoFormatPropertiesKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_FORMAT_PROPERTIES_KHR

    • VUID-VkVideoFormatPropertiesKHR-pNext-pNext
      pNext must be NULL

    36.5. Video Sessions

    Video sessions are objects that represent and maintain the state needed to perform video decode or encode operations using a specific video profile.

    Video sessions are represented by VkVideoSessionKHR handles:

    // Provided by VK_KHR_video_queue
VK_DEFINE_NON_DISPATCHABLE_HANDLE(VkVideoSessionKHR)

    36.5.1. Creating a Video Session

    To create a video session object, call:

    // Provided by VK_KHR_video_queue
VkResult vkCreateVideoSessionKHR(
    VkDevice                                    device,
    const VkVideoSessionCreateInfoKHR*          pCreateInfo,
    const VkAllocationCallbacks*                pAllocator,
    VkVideoSessionKHR*                          pVideoSession);

    • device is the logical device that creates the video session.

    • pCreateInfo is a pointer to a VkVideoSessionCreateInfoKHR structure containing parameters to be used to create the video session.

    • pAllocator controls host memory allocation as described in the Memory Allocation chapter.

    • pVideoSession is a pointer to a VkVideoSessionKHR handle in which the resulting video session object is returned.

    The resulting video session object is said to be created with the video codec operation specified in pCreateInfo->pVideoProfile->videoCodecOperation.

    The name and version of the codec-specific Video Std header to be used with the video session is specified by the VkExtensionProperties structure pointed to by pCreateInfo->pStdHeaderVersion. If a non-existent or unsupported Video Std header version is specified in pCreateInfo->pStdHeaderVersion->specVersion, then this command returns VK_ERROR_VIDEO_STD_VERSION_NOT_SUPPORTED_KHR.

    Video session objects are created in uninitialized state. In order to transition the video session into initial state, the application must issue a vkCmdControlVideoCodingKHR command with VkVideoCodingControlInfoKHR::flags including VK_VIDEO_CODING_CONTROL_RESET_BIT_KHR.

    Video session objects also maintain the state of the DPB. The number of DPB slots usable with the created video session is specified in pCreateInfo->maxDpbSlots, and each slot is initially in the inactive state.

    Each DPB slot maintained by the created video session can refer to a reference picture representing a video frame.

    In addition, if the videoCodecOperation member of the VkVideoProfileInfoKHR structure pointed to by pCreateInfo->pVideoProfile is VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR and the pictureLayout member of the VkVideoDecodeH264ProfileInfoKHR structure provided in the VkVideoProfileInfoKHR::pNext chain is not VK_VIDEO_DECODE_H264_PICTURE_LAYOUT_PROGRESSIVE_KHR, then the created video session supports interlaced frames and each DPB slot maintained by the created video session can instead refer to separate top field and bottom field reference pictures that together can represent a full video frame. In this case, it is up to the application, driven by the video content, whether it associates any individual DPB slot with separate top and/or bottom field pictures or a single picture representing a full frame.

    The created video session can be used to perform video coding operations using video frames up to the maximum size specified in pCreateInfo->maxCodedExtent. The minimum frame size allowed is implicitly derived from VkVideoCapabilitiesKHR::minCodedExtent, as returned by vkGetPhysicalDeviceVideoCapabilitiesKHR for the video profile specified by pCreateInfo->pVideoProfile. Accordingly, the created video session is said to be created with a minCodedExtent equal to that.

    In case of video session objects created with a video encode operation, implementations may return the VK_ERROR_INVALID_VIDEO_STD_PARAMETERS_KHR error if any of the specified Video Std parameters do not adhere to the syntactic or semantic requirements of the used video compression standard, or if values derived from parameters according to the rules defined by the used video compression standard do not adhere to the capabilities of the video compression standard or the implementation.

    Note

    Applications should not rely on the VK_ERROR_INVALID_VIDEO_STD_PARAMETERS_KHR error being returned by any command as a means to verify Video Std parameters, as implementations are not required to report the error in any specific set of cases.
    Valid Usage (Implicit)

    • VUID-vkCreateVideoSessionKHR-device-parameter
      device must be a valid VkDevice handle

    • VUID-vkCreateVideoSessionKHR-pCreateInfo-parameter
      pCreateInfo must be a valid pointer to a valid VkVideoSessionCreateInfoKHR structure

    • VUID-vkCreateVideoSessionKHR-pAllocator-parameter
      If pAllocator is not NULL, pAllocator must be a valid pointer to a valid VkAllocationCallbacks structure

    • VUID-vkCreateVideoSessionKHR-pVideoSession-parameter
      pVideoSession must be a valid pointer to a VkVideoSessionKHR handle

    Return Codes
    Success

    • VK_SUCCESS

    Failure

    • VK_ERROR_OUT_OF_HOST_MEMORY

    • VK_ERROR_OUT_OF_DEVICE_MEMORY

    • VK_ERROR_INITIALIZATION_FAILED

    • VK_ERROR_VIDEO_STD_VERSION_NOT_SUPPORTED_KHR

    • VK_ERROR_INVALID_VIDEO_STD_PARAMETERS_KHR

    The VkVideoSessionCreateInfoKHR structure is defined as:

    // Provided by VK_KHR_video_queue
typedef struct VkVideoSessionCreateInfoKHR {
    VkStructureType                 sType;
    const void*                     pNext;
    uint32_t                        queueFamilyIndex;
    VkVideoSessionCreateFlagsKHR    flags;
    const VkVideoProfileInfoKHR*    pVideoProfile;
    VkFormat                        pictureFormat;
    VkExtent2D                      maxCodedExtent;
    VkFormat                        referencePictureFormat;
    uint32_t                        maxDpbSlots;
    uint32_t                        maxActiveReferencePictures;
    const VkExtensionProperties*    pStdHeaderVersion;
} VkVideoSessionCreateInfoKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • queueFamilyIndex is the index of the queue family the created video session will be used with.

    • flags is a bitmask of VkVideoSessionCreateFlagBitsKHR specifying creation flags.

    • pVideoProfile is a pointer to a VkVideoProfileInfoKHR structure specifying the video profile the created video session will be used with.

    • pictureFormat is the image format the created video session will be used with. If pVideoProfile->videoCodecOperation specifies a decode operation, then pictureFormat is the image format of decode output pictures usable with the created video session. If pVideoProfile->videoCodecOperation specifies an encode operation, then pictureFormat is the image format of encode input pictures usable with the created video session.

    • maxCodedExtent is the maximum width and height of the coded frames the created video session will be used with.

    • referencePictureFormat is the image format of reference pictures stored in the DPB the created video session will be used with.

    • maxDpbSlots is the maximum number of DPB Slots that can be used with the created video session.

    • maxActiveReferencePictures is the maximum number of active reference pictures that can be used in a single video coding operation using the created video session.

    • pStdHeaderVersion is a pointer to a VkExtensionProperties structure requesting the Video Std header version to use for the videoCodecOperation specified in pVideoProfile.

    Valid Usage

    • VUID-VkVideoSessionCreateInfoKHR-protectedMemory-07189
      If the protectedMemory feature is not enabled or if VkVideoCapabilitiesKHR::flags does not include VK_VIDEO_CAPABILITY_PROTECTED_CONTENT_BIT_KHR, as returned by vkGetPhysicalDeviceVideoCapabilitiesKHR for the video profile specified by pVideoProfile, then flags must not include VK_VIDEO_SESSION_CREATE_PROTECTED_CONTENT_BIT_KHR

    • VUID-VkVideoSessionCreateInfoKHR-pVideoProfile-04845
      pVideoProfile must be a supported video profile

    • VUID-VkVideoSessionCreateInfoKHR-maxDpbSlots-04847
      maxDpbSlots must be less than or equal to VkVideoCapabilitiesKHR::maxDpbSlots, as returned by vkGetPhysicalDeviceVideoCapabilitiesKHR for the video profile specified by pVideoProfile

    • VUID-VkVideoSessionCreateInfoKHR-maxActiveReferencePictures-04849
      maxActiveReferencePictures must be less than or equal to VkVideoCapabilitiesKHR::maxActiveReferencePictures, as returned by vkGetPhysicalDeviceVideoCapabilitiesKHR for the video profile specified by pVideoProfile

    • VUID-VkVideoSessionCreateInfoKHR-maxDpbSlots-04850
      If either maxDpbSlots or maxActiveReferencePictures is 0, then both must be 0

    • VUID-VkVideoSessionCreateInfoKHR-maxCodedExtent-04851
      maxCodedExtent must be between VkVideoCapabilitiesKHR::minCodedExtent and VkVideoCapabilitiesKHR::maxCodedExtent, inclusive, as returned by vkGetPhysicalDeviceVideoCapabilitiesKHR for the video profile specified by pVideoProfile

    • VUID-VkVideoSessionCreateInfoKHR-referencePictureFormat-04852
      If pVideoProfile->videoCodecOperation specifies a decode operation and maxActiveReferencePictures is greater than 0, then referencePictureFormat must be one of the supported decode DPB formats, as returned by vkGetPhysicalDeviceVideoFormatPropertiesKHR in VkVideoFormatPropertiesKHR::format when called with the imageUsage member of its pVideoFormatInfo parameter containing VK_IMAGE_USAGE_VIDEO_DECODE_DPB_BIT_KHR, and with a VkVideoProfileListInfoKHR structure specified in the pNext chain of its pVideoFormatInfo parameter whose pProfiles member contains an element matching pVideoProfile

    • VUID-VkVideoSessionCreateInfoKHR-referencePictureFormat-06814
      If pVideoProfile->videoCodecOperation specifies an encode operation and maxActiveReferencePictures is greater than 0, then referencePictureFormat must be one of the supported decode DPB formats, as returned by then referencePictureFormat must be one of the supported encode DPB formats, as returned by vkGetPhysicalDeviceVideoFormatPropertiesKHR in VkVideoFormatPropertiesKHR::format when called with the imageUsage member of its pVideoFormatInfo parameter containing VK_IMAGE_USAGE_VIDEO_ENCODE_DPB_BIT_KHR, and with a VkVideoProfileListInfoKHR structure specified in the pNext chain of its pVideoFormatInfo parameter whose pProfiles member contains an element matching pVideoProfile

    • VUID-VkVideoSessionCreateInfoKHR-pictureFormat-04853
      If pVideoProfile->videoCodecOperation specifies a decode operation, then pictureFormat must be one of the supported decode output formats, as returned by vkGetPhysicalDeviceVideoFormatPropertiesKHR in VkVideoFormatPropertiesKHR::format when called with the imageUsage member of its pVideoFormatInfo parameter containing VK_IMAGE_USAGE_VIDEO_DECODE_DST_BIT_KHR, and with a VkVideoProfileListInfoKHR structure specified in the pNext chain of its pVideoFormatInfo parameter whose pProfiles member contains an element matching pVideoProfile

    • VUID-VkVideoSessionCreateInfoKHR-pictureFormat-04854
      If pVideoProfile->videoCodecOperation specifies an encode operation, then pictureFormat must be one of the supported encode input formats, as returned by vkGetPhysicalDeviceVideoFormatPropertiesKHR in VkVideoFormatPropertiesKHR::format when called with the imageUsage member of its pVideoFormatInfo parameter containing VK_IMAGE_USAGE_VIDEO_ENCODE_SRC_BIT_KHR, and with a VkVideoProfileListInfoKHR structure specified in the pNext chain of its pVideoFormatInfo parameter whose pProfiles member contains an element matching pVideoProfile

    • VUID-VkVideoSessionCreateInfoKHR-pStdHeaderVersion-07190
      pStdHeaderVersion->extensionName must match VkVideoCapabilitiesKHR::stdHeaderVersion.extensionName, as returned by vkGetPhysicalDeviceVideoCapabilitiesKHR for the video profile specified by pVideoProfile

    • VUID-VkVideoSessionCreateInfoKHR-pStdHeaderVersion-07191
      pStdHeaderVersion->specVersion must be less than or equal to VkVideoCapabilitiesKHR::stdHeaderVersion.specVersion, as returned by vkGetPhysicalDeviceVideoCapabilitiesKHR for the video profile specified by pVideoProfile

    Valid Usage (Implicit)

    • VUID-VkVideoSessionCreateInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_SESSION_CREATE_INFO_KHR

    • VUID-VkVideoSessionCreateInfoKHR-pNext-pNext
      pNext must be NULL

    • VUID-VkVideoSessionCreateInfoKHR-flags-parameter
      flags must be a valid combination of VkVideoSessionCreateFlagBitsKHR values

    • VUID-VkVideoSessionCreateInfoKHR-pVideoProfile-parameter
      pVideoProfile must be a valid pointer to a valid VkVideoProfileInfoKHR structure

    • VUID-VkVideoSessionCreateInfoKHR-pictureFormat-parameter
      pictureFormat must be a valid VkFormat value

    • VUID-VkVideoSessionCreateInfoKHR-referencePictureFormat-parameter
      referencePictureFormat must be a valid VkFormat value

    • VUID-VkVideoSessionCreateInfoKHR-pStdHeaderVersion-parameter
      pStdHeaderVersion must be a valid pointer to a valid VkExtensionProperties structure

    Bits which can be set in VkVideoSessionCreateInfoKHR::flags are:

    // Provided by VK_KHR_video_queue
typedef enum VkVideoSessionCreateFlagBitsKHR {
    VK_VIDEO_SESSION_CREATE_PROTECTED_CONTENT_BIT_KHR = 0x00000001,
} VkVideoSessionCreateFlagBitsKHR;

    • VK_VIDEO_SESSION_CREATE_PROTECTED_CONTENT_BIT_KHR specifies that the video session uses protected video content.

    // Provided by VK_KHR_video_queue
typedef VkFlags VkVideoSessionCreateFlagsKHR;

    VkVideoSessionCreateFlagsKHR is a bitmask type for setting a mask of zero or more VkVideoSessionCreateFlagBitsKHR.

    36.5.2. Destroying a Video Session

    To destroy a video session, call:

    // Provided by VK_KHR_video_queue
void vkDestroyVideoSessionKHR(
    VkDevice                                    device,
    VkVideoSessionKHR                           videoSession,
    const VkAllocationCallbacks*                pAllocator);

    • device is the logical device that destroys the video session.

    • videoSession is the video session to destroy.

    • pAllocator controls host memory allocation as described in the Memory Allocation chapter.

    Valid Usage

    • VUID-vkDestroyVideoSessionKHR-videoSession-07192
      All submitted commands that refer to videoSession must have completed execution

    • VUID-vkDestroyVideoSessionKHR-videoSession-07193
      If VkAllocationCallbacks were provided when videoSession was created, a compatible set of callbacks must be provided here

    • VUID-vkDestroyVideoSessionKHR-videoSession-07194
      If no VkAllocationCallbacks were provided when videoSession was created, pAllocator must be NULL

    Valid Usage (Implicit)

    • VUID-vkDestroyVideoSessionKHR-device-parameter
      device must be a valid VkDevice handle

    • VUID-vkDestroyVideoSessionKHR-videoSession-parameter
      If videoSession is not VK_NULL_HANDLE, videoSession must be a valid VkVideoSessionKHR handle

    • VUID-vkDestroyVideoSessionKHR-pAllocator-parameter
      If pAllocator is not NULL, pAllocator must be a valid pointer to a valid VkAllocationCallbacks structure

    • VUID-vkDestroyVideoSessionKHR-videoSession-parent
      If videoSession is a valid handle, it must have been created, allocated, or retrieved from device

    Host Synchronization

    • Host access to videoSession must be externally synchronized

    36.5.3. Video Session Memory Association

    After creating a video session object, and before the object can be used to record video coding operations into command buffers using it, the application must allocate and bind device memory to the video session. Device memory is allocated separately (see Device Memory) and then associated with the video session.

    Video sessions may have multiple memory bindings identified by unique unsigned integer values. Appropriate device memory must be bound to each such memory binding before using the video session to record command buffer commands with it.

    To determine the memory requirements for a video session object, call:

    // Provided by VK_KHR_video_queue
VkResult vkGetVideoSessionMemoryRequirementsKHR(
    VkDevice                                    device,
    VkVideoSessionKHR                           videoSession,
    uint32_t*                                   pMemoryRequirementsCount,
    VkVideoSessionMemoryRequirementsKHR*        pMemoryRequirements);

    • device is the logical device that owns the video session.

    • videoSession is the video session to query.

    • pMemoryRequirementsCount is a pointer to an integer related to the number of memory binding requirements available or queried, as described below.

    • pMemoryRequirements is NULL or a pointer to an array of VkVideoSessionMemoryRequirementsKHR structures in which the memory binding requirements of the video session are returned.

    If pMemoryRequirements is NULL, then the number of memory bindings required for the video session is returned in pMemoryRequirementsCount. Otherwise, pMemoryRequirementsCount must point to a variable set by the user with the number of elements in the pMemoryRequirements array, and on return the variable is overwritten with the number of memory binding requirements actually written to pMemoryRequirements. If pMemoryRequirementsCount is less than the number of memory bindings required for the video session, then at most pMemoryRequirementsCount elements will be written to pMemoryRequirements, and VK_INCOMPLETE will be returned, instead of VK_SUCCESS, to indicate that not all required memory binding requirements were returned.

    Valid Usage (Implicit)

    • VUID-vkGetVideoSessionMemoryRequirementsKHR-device-parameter
      device must be a valid VkDevice handle

    • VUID-vkGetVideoSessionMemoryRequirementsKHR-videoSession-parameter
      videoSession must be a valid VkVideoSessionKHR handle

    • VUID-vkGetVideoSessionMemoryRequirementsKHR-pMemoryRequirementsCount-parameter
      pMemoryRequirementsCount must be a valid pointer to a uint32_t value

    • VUID-vkGetVideoSessionMemoryRequirementsKHR-pMemoryRequirements-parameter
      If the value referenced by pMemoryRequirementsCount is not 0, and pMemoryRequirements is not NULL, pMemoryRequirements must be a valid pointer to an array of pMemoryRequirementsCount VkVideoSessionMemoryRequirementsKHR structures

    • VUID-vkGetVideoSessionMemoryRequirementsKHR-videoSession-parent
      videoSession must have been created, allocated, or retrieved from device

    Return Codes
    Success

    • VK_SUCCESS

    • VK_INCOMPLETE

    The VkVideoSessionMemoryRequirementsKHR structure is defined as:

    // Provided by VK_KHR_video_queue
typedef struct VkVideoSessionMemoryRequirementsKHR {
    VkStructureType         sType;
    void*                   pNext;
    uint32_t                memoryBindIndex;
    VkMemoryRequirements    memoryRequirements;
} VkVideoSessionMemoryRequirementsKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • memoryBindIndex is the index of the memory binding.

    • memoryRequirements is a VkMemoryRequirements structure in which the requested memory binding requirements for the binding index specified by memoryBindIndex are returned.

    Valid Usage (Implicit)

    • VUID-VkVideoSessionMemoryRequirementsKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_SESSION_MEMORY_REQUIREMENTS_KHR

    • VUID-VkVideoSessionMemoryRequirementsKHR-pNext-pNext
      pNext must be NULL

    To attach memory to a video session object, call:

    // Provided by VK_KHR_video_queue
VkResult vkBindVideoSessionMemoryKHR(
    VkDevice                                    device,
    VkVideoSessionKHR                           videoSession,
    uint32_t                                    bindSessionMemoryInfoCount,
    const VkBindVideoSessionMemoryInfoKHR*      pBindSessionMemoryInfos);

    • device is the logical device that owns the video session.

    • videoSession is the video session to be bound with device memory.

    • bindSessionMemoryInfoCount is the number of elements in pBindSessionMemoryInfos.

    • pBindSessionMemoryInfos is a pointer to an array of bindSessionMemoryInfoCount VkBindVideoSessionMemoryInfoKHR structures specifying memory regions to be bound to specific memory bindings of the video session.

    The valid usage statements below refer to the VkMemoryRequirements structure corresponding to a specific element of pBindSessionMemoryInfos, which is defined as follows:

    • If the memoryBindIndex member of the element of pBindSessionMemoryInfos in question matches the memoryBindIndex member of one of the elements returned in pMemoryRequirements when vkGetVideoSessionMemoryRequirementsKHR is called with the same videoSession and with pMemoryRequirementsCount equal to bindSessionMemoryInfoCount, then the memoryRequirements member of that element of pMemoryRequirements is the VkMemoryRequirements structure corresponding to the element of pBindSessionMemoryInfos in question.

    • Otherwise the element of pBindSessionMemoryInfos in question is said to not have a corresponding VkMemoryRequirements structure.

    Valid Usage

    • VUID-vkBindVideoSessionMemoryKHR-videoSession-07195
      The memory binding of videoSession identified by the memoryBindIndex member of any element of pBindSessionMemoryInfos must not already be backed by a memory object

    • VUID-vkBindVideoSessionMemoryKHR-memoryBindIndex-07196
      The memoryBindIndex member of each element of pBindSessionMemoryInfos must be unique within pBindSessionMemoryInfos

    • VUID-vkBindVideoSessionMemoryKHR-pBindSessionMemoryInfos-07197
      Each element of pBindSessionMemoryInfos must have a corresponding VkMemoryRequirements structure

    • VUID-vkBindVideoSessionMemoryKHR-pBindSessionMemoryInfos-07198
      If an element of pBindSessionMemoryInfos has a corresponding VkMemoryRequirements structure, then the memory member of that element of pBindSessionMemoryInfos must have been allocated using one of the memory types allowed in the memoryTypeBits member of the corresponding VkMemoryRequirements structure

    • VUID-vkBindVideoSessionMemoryKHR-pBindSessionMemoryInfos-07199
      If an element of pBindSessionMemoryInfos has a corresponding VkMemoryRequirements structure, then the memoryOffset member of that element of pBindSessionMemoryInfos must be an integer multiple of the alignment member of the corresponding VkMemoryRequirements structure

    • VUID-vkBindVideoSessionMemoryKHR-pBindSessionMemoryInfos-07200
      If an element of pBindSessionMemoryInfos has a corresponding VkMemoryRequirements structure, then the memorySize member of that element of pBindSessionMemoryInfos must equal the size member of the corresponding VkMemoryRequirements structure

    Valid Usage (Implicit)

    • VUID-vkBindVideoSessionMemoryKHR-device-parameter
      device must be a valid VkDevice handle

    • VUID-vkBindVideoSessionMemoryKHR-videoSession-parameter
      videoSession must be a valid VkVideoSessionKHR handle

    • VUID-vkBindVideoSessionMemoryKHR-pBindSessionMemoryInfos-parameter
      pBindSessionMemoryInfos must be a valid pointer to an array of bindSessionMemoryInfoCount valid VkBindVideoSessionMemoryInfoKHR structures

    • VUID-vkBindVideoSessionMemoryKHR-bindSessionMemoryInfoCount-arraylength
      bindSessionMemoryInfoCount must be greater than 0

    • VUID-vkBindVideoSessionMemoryKHR-videoSession-parent
      videoSession must have been created, allocated, or retrieved from device

    Host Synchronization

    • Host access to videoSession must be externally synchronized

    Return Codes
    Success

    • VK_SUCCESS

    Failure

    • VK_ERROR_OUT_OF_HOST_MEMORY

    • VK_ERROR_OUT_OF_DEVICE_MEMORY

    The VkBindVideoSessionMemoryInfoKHR structure is defined as:

    // Provided by VK_KHR_video_queue
typedef struct VkBindVideoSessionMemoryInfoKHR {
    VkStructureType    sType;
    const void*        pNext;
    uint32_t           memoryBindIndex;
    VkDeviceMemory     memory;
    VkDeviceSize       memoryOffset;
    VkDeviceSize       memorySize;
} VkBindVideoSessionMemoryInfoKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • memoryBindIndex is the memory binding index to bind memory to.

    • memory is the allocated device memory to be bound to the video session’s memory binding with index memoryBindIndex.

    • memoryOffset is the start offset of the region of memory which is to be bound.

    • memorySize is the size in bytes of the region of memory, starting from memoryOffset bytes, to be bound.

    Valid Usage

    • VUID-VkBindVideoSessionMemoryInfoKHR-memoryOffset-07201
      memoryOffset must be less than the size of memory

    • VUID-VkBindVideoSessionMemoryInfoKHR-memorySize-07202
      memorySize must be less than or equal to the size of memory minus memoryOffset

    Valid Usage (Implicit)

    • VUID-VkBindVideoSessionMemoryInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_BIND_VIDEO_SESSION_MEMORY_INFO_KHR

    • VUID-VkBindVideoSessionMemoryInfoKHR-pNext-pNext
      pNext must be NULL

    • VUID-VkBindVideoSessionMemoryInfoKHR-memory-parameter
      memory must be a valid VkDeviceMemory handle

    36.6. Video Profile Compatibility

    Resources and query pools used with a particular video session must be compatible with the video profile the video session was created with.

    A VkBuffer is compatible with a video profile if it was created with the VkBufferCreateInfo::pNext chain including a VkVideoProfileListInfoKHR structure with its pProfiles member containing an element matching the VkVideoProfileInfoKHR structure chain describing the video profile, and VkBufferCreateInfo::usage including at least one bit specific to video coding usage.

    • VK_BUFFER_USAGE_VIDEO_DECODE_SRC_BIT_KHR

    • VK_BUFFER_USAGE_VIDEO_DECODE_DST_BIT_KHR

    • VK_BUFFER_USAGE_VIDEO_ENCODE_SRC_BIT_KHR

    • VK_BUFFER_USAGE_VIDEO_ENCODE_DST_BIT_KHR

    A VkImage is compatible with a video profile if it was created with the VkImageCreateInfo::pNext chain including a VkVideoProfileListInfoKHR structure with its pProfiles member containing an element matching the VkVideoProfileInfoKHR structure chain describing the video profile, and VkImageCreateInfo::usage including at least one bit specific to video coding usage.

    • VK_IMAGE_USAGE_VIDEO_DECODE_SRC_BIT_KHR

    • VK_IMAGE_USAGE_VIDEO_DECODE_DST_BIT_KHR

    • VK_IMAGE_USAGE_VIDEO_DECODE_DPB_BIT_KHR

    • VK_IMAGE_USAGE_VIDEO_ENCODE_SRC_BIT_KHR

    • VK_IMAGE_USAGE_VIDEO_ENCODE_DST_BIT_KHR

    • VK_IMAGE_USAGE_VIDEO_ENCODE_DPB_BIT_KHR

    A VkImageView is compatible with a video profile if the VkImage it was created from is also compatible with that video profile.

    A VkQueryPool is compatible with a video profile if it was created with the VkQueryPoolCreateInfo::pNext chain including a VkVideoProfileInfoKHR structure chain describing the same video profile, and VkQueryPoolCreateInfo::queryType having one of the following values:

    • VK_QUERY_TYPE_RESULT_STATUS_ONLY_KHR

    • VK_QUERY_TYPE_VIDEO_ENCODE_FEEDBACK_KHR

    36.7. Video Session Parameters

    Video session parameters objects can store preprocessed codec-specific parameters used with a compatible video session, and enable reducing the number of parameters needed to be provided and processed by the implementation while recording video coding operations into command buffers.

    Parameters stored in such objects are immutable to facilitate the concurrent use of the stored parameters in multiple threads. At the same time, new parameters can be added to existing objects using the vkUpdateVideoSessionParametersKHR command.

    In order to support concurrent use of the stored immutable parameters while also allowing the video session parameters object to be extended with new parameters, each video session parameters object maintains an update sequence counter that is set to 0 at object creation time and must be incremented by each subsequent update operation.

    Certain video sequences that adhere to particular video compression standards permit updating previously supplied parameters. If a parameter update is necessary, the application has the following options:

    • Cache the set of parameters on the application side and create a new video session parameters object adding all the parameters with appropriate changes, as necessary; or

    • Create a new video session parameters object providing only the updated parameters and the previously used object as the template, which ensures that parameters not specified at creation time will be copied unmodified from the template object.

    The actual types of parameters that can be stored and the capacity for individual parameter types, and the methods of initializing, updating, and referring to individual parameters are specific to the video codec operation the video session parameters object was created with.

    Video session parameters are represented by VkVideoSessionParametersKHR handles:

    // Provided by VK_KHR_video_queue
VK_DEFINE_NON_DISPATCHABLE_HANDLE(VkVideoSessionParametersKHR)

    36.7.1. Creating Video Session Parameters

    To create a video session parameters object, call:

    // Provided by VK_KHR_video_queue
VkResult vkCreateVideoSessionParametersKHR(
    VkDevice                                    device,
    const VkVideoSessionParametersCreateInfoKHR* pCreateInfo,
    const VkAllocationCallbacks*                pAllocator,
    VkVideoSessionParametersKHR*                pVideoSessionParameters);

    • device is the logical device that creates the video session parameters object.

    • pCreateInfo is a pointer to VkVideoSessionParametersCreateInfoKHR structure containing parameters to be used to create the video session parameters object.

    • pAllocator controls host memory allocation as described in the Memory Allocation chapter.

    • pVideoSessionParameters is a pointer to a VkVideoSessionParametersKHR handle in which the resulting video session parameters object is returned.

    The resulting video session parameters object is said to be created with the video codec operation pCreateInfo->videoSession was created with.

    If pCreateInfo->videoSessionParametersTemplate is not VK_NULL_HANDLE, then it will be used as a template for constructing the new video session parameters object. This happens by first adding any parameters according to the additional creation parameters provided in the pCreateInfo->pNext chain, followed by adding any parameters from the template object that have a key that does not match the key of any of the already added parameters.

    If pCreateInfo->videoSession was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR, then the created video session parameters object will initially contain the following sets of parameter entries:

    • StdVideoH264SequenceParameterSet structures representing H.264 SPS entries, as follows:

      • If the pParametersAddInfo member of the VkVideoDecodeH264SessionParametersCreateInfoKHR structure provided in the pCreateInfo->pNext chain is not NULL, then the set of StdVideoH264SequenceParameterSet entries specified in pParametersAddInfo->pStdSPSs are added first;

      • If pCreateInfo->videoSessionParametersTemplate is not VK_NULL_HANDLE, then each StdVideoH264SequenceParameterSet entry stored in it is copied to the created video session parameters object if the created object does not already contain such an entry with the same seq_parameter_set_id.

    • StdVideoH264PictureParameterSet structures representing H.264 PPS entries, as follows:

      • If the pParametersAddInfo member of the VkVideoDecodeH264SessionParametersCreateInfoKHR structure provided in the pCreateInfo->pNext chain is not NULL, then the set of StdVideoH264PictureParameterSet entries specified in pParametersAddInfo->pStdPPSs are added first;

      • If pCreateInfo->videoSessionParametersTemplate is not VK_NULL_HANDLE, then each StdVideoH264PictureParameterSet entry stored in it is copied to the created video session parameters object if the created object does not already contain such an entry with the same seq_parameter_set_id and pic_parameter_set_id.

    If pCreateInfo->videoSession was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR, then the created video session parameters object will initially contain the following sets of parameter entries:

    • StdVideoH265VideoParameterSet structures representing H.264 VPS entries, as follows:

      • If the pParametersAddInfo member of the VkVideoDecodeH265SessionParametersCreateInfoKHR structure provided in the pCreateInfo->pNext chain is not NULL, then the set of StdVideoH265VideoParameterSet entries specified in pParametersAddInfo->pStdVPSs are added first;

      • If pCreateInfo->videoSessionParametersTemplate is not VK_NULL_HANDLE, then each StdVideoH265VideoParameterSet entry stored in it is copied to the created video session parameters object if the created object does not already contain such an entry with the same vps_video_parameter_set_id.

    • StdVideoH265SequenceParameterSet structures representing H.265 SPS entries, as follows:

      • If the pParametersAddInfo member of the VkVideoDecodeH265SessionParametersCreateInfoKHR structure provided in the pCreateInfo->pNext chain is not NULL, then the set of StdVideoH265SequenceParameterSet entries specified in pParametersAddInfo->pStdSPSs are added first;

      • If pCreateInfo->videoSessionParametersTemplate is not VK_NULL_HANDLE, then each StdVideoH265SequenceParameterSet entry stored in it is copied to the created video session parameters object if the created object does not already contain such an entry with the same sps_video_parameter_set_id and sps_seq_parameter_set_id.

    • StdVideoH265PictureParameterSet structures representing H.265 PPS entries, as follows:

      • If the pParametersAddInfo member of the VkVideoDecodeH265SessionParametersCreateInfoKHR structure provided in the pCreateInfo->pNext chain is not NULL, then the set of StdVideoH265PictureParameterSet entries specified in pParametersAddInfo->pStdPPSs are added first;

      • If pCreateInfo->videoSessionParametersTemplate is not VK_NULL_HANDLE, then each StdVideoH265PictureParameterSet entry stored in it is copied to the created video session parameters object if the created object does not already contain such an entry with the same sps_video_parameter_set_id, pps_seq_parameter_set_id, and pps_pic_parameter_set_id.

    In case of video session parameters objects created with a video encode operation, implementations may return the VK_ERROR_INVALID_VIDEO_STD_PARAMETERS_KHR error if any of the specified Video Std parameters do not adhere to the syntactic or semantic requirements of the used video compression standard, or if values derived from parameters according to the rules defined by the used video compression standard do not adhere to the capabilities of the video compression standard or the implementation.

    Note

    Applications should not rely on the VK_ERROR_INVALID_VIDEO_STD_PARAMETERS_KHR error being returned by any command as a means to verify Video Std parameters, as implementations are not required to report the error in any specific set of cases.
    Valid Usage (Implicit)

    • VUID-vkCreateVideoSessionParametersKHR-device-parameter
      device must be a valid VkDevice handle

    • VUID-vkCreateVideoSessionParametersKHR-pCreateInfo-parameter
      pCreateInfo must be a valid pointer to a valid VkVideoSessionParametersCreateInfoKHR structure

    • VUID-vkCreateVideoSessionParametersKHR-pAllocator-parameter
      If pAllocator is not NULL, pAllocator must be a valid pointer to a valid VkAllocationCallbacks structure

    • VUID-vkCreateVideoSessionParametersKHR-pVideoSessionParameters-parameter
      pVideoSessionParameters must be a valid pointer to a VkVideoSessionParametersKHR handle

    Return Codes
    Success

    • VK_SUCCESS

    Failure

    • VK_ERROR_OUT_OF_HOST_MEMORY

    • VK_ERROR_OUT_OF_DEVICE_MEMORY

    • VK_ERROR_INITIALIZATION_FAILED

    • VK_ERROR_INVALID_VIDEO_STD_PARAMETERS_KHR

    The VkVideoSessionParametersCreateInfoKHR structure is defined as:

    // Provided by VK_KHR_video_queue
typedef struct VkVideoSessionParametersCreateInfoKHR {
    VkStructureType                           sType;
    const void*                               pNext;
    VkVideoSessionParametersCreateFlagsKHR    flags;
    VkVideoSessionParametersKHR               videoSessionParametersTemplate;
    VkVideoSessionKHR                         videoSession;
} VkVideoSessionParametersCreateInfoKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • flags is reserved for future use.

    • videoSessionParametersTemplate is VK_NULL_HANDLE or a valid handle to a VkVideoSessionParametersKHR object used as a template for constructing the new video session parameters object.

    • videoSession is the video session object against which the video session parameters object is going to be created.

    Limiting values are defined below that are referenced by the relevant valid usage statements of this structure.

    • If videoSession was created with the codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR, then let StdVideoH264SequenceParameterSet spsAddList[] be the list of H.264 SPS entries to add to the created video session parameters object, defined as follows:

      • If the pParametersAddInfo member of the VkVideoDecodeH264SessionParametersCreateInfoKHR structure provided in the pNext chain is not NULL, then the set of StdVideoH264SequenceParameterSet entries specified in pParametersAddInfo->pStdSPSs are added to spsAddList;

      • If videoSessionParametersTemplate is not VK_NULL_HANDLE, then each StdVideoH264SequenceParameterSet entry stored in it with seq_parameter_set_id not matching any of the entries already in spsAddList is added to spsAddList.

    • If videoSession was created with the codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR, then let StdVideoH264PictureParameterSet ppsAddList[] be the list of H.264 PPS entries to add to the created video session parameters object, defined as follows:

      • If the pParametersAddInfo member of the VkVideoDecodeH264SessionParametersCreateInfoKHR structure provided in the pNext chain is not NULL, then the set of StdVideoH264PictureParameterSet entries specified in pParametersAddInfo->pStdPPSs are added to ppsAddList;

      • If videoSessionParametersTemplate is not VK_NULL_HANDLE, then each StdVideoH264PictureParameterSet entry stored in it with seq_parameter_set_id or pic_parameter_set_id not matching any of the entries already in ppsAddList is added to ppsAddList.

    • If videoSession was created with the codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR, then let StdVideoH265VideoParameterSet vpsAddList[] be the list of H.265 VPS entries to add to the created video session parameters object, defined as follows:

      • If the pParametersAddInfo member of the VkVideoDecodeH265SessionParametersCreateInfoKHR structure provided in the pNext chain is not NULL, then the set of StdVideoH265VideoParameterSet entries specified in pParametersAddInfo->pStdVPSs are added to vpsAddList;

      • If videoSessionParametersTemplate is not VK_NULL_HANDLE, then each StdVideoH265VideoParameterSet entry stored in it with vps_video_parameter_set_id not matching any of the entries already in vpsAddList is added to vpsAddList.

    • If videoSession was created with the codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR, then let StdVideoH265SequenceParameterSet spsAddList[] be the list of H.265 SPS entries to add to the created video session parameters object, defined as follows:

      • If the pParametersAddInfo member of the VkVideoDecodeH265SessionParametersCreateInfoKHR structure provided in the pNext chain is not NULL, then the set of StdVideoH265SequenceParameterSet entries specified in pParametersAddInfo->pStdSPSs are added to spsAddList;

      • If videoSessionParametersTemplate is not VK_NULL_HANDLE, then each StdVideoH265SequenceParameterSet entry stored in it with sps_video_parameter_set_id or sps_seq_parameter_set_id not matching any of the entries already in spsAddList is added to spsAddList.

    • If videoSession was created with the codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR, then let StdVideoH265PictureParameterSet ppsAddList[] be the list of H.265 PPS entries to add to the created video session parameters object, defined as follows:

      • If the pParametersAddInfo member of the VkVideoDecodeH265SessionParametersCreateInfoKHR structure provided in the pNext chain is not NULL, then the set of StdVideoH265PictureParameterSet entries specified in pParametersAddInfo->pStdPPSs are added to ppsAddList;

      • If videoSessionParametersTemplate is not VK_NULL_HANDLE, then each StdVideoH265PictureParameterSet entry stored in it with sps_video_parameter_set_id, pps_seq_parameter_set_id, or pps_pic_parameter_set_id not matching any of the entries already in ppsAddList is added to ppsAddList.

    Valid Usage

    • VUID-VkVideoSessionParametersCreateInfoKHR-videoSessionParametersTemplate-04855
      If videoSessionParametersTemplate represents a valid handle, it must have been created against videoSession

    • VUID-VkVideoSessionParametersCreateInfoKHR-videoSession-07203
      If videoSession was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR, then the pNext chain must include a VkVideoDecodeH264SessionParametersCreateInfoKHR structure

    • VUID-VkVideoSessionParametersCreateInfoKHR-videoSession-07204
      If videoSession was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR, then the number of elements of spsAddList must be less than or equal to the maxStdSPSCount specified in the VkVideoDecodeH264SessionParametersCreateInfoKHR structure included in the pNext chain

    • VUID-VkVideoSessionParametersCreateInfoKHR-videoSession-07205
      If videoSession was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR, then the number of elements of ppsAddList must be less than or equal to the maxStdPPSCount specified in the VkVideoDecodeH264SessionParametersCreateInfoKHR structure included in the pNext chain

    • VUID-VkVideoSessionParametersCreateInfoKHR-videoSession-07206
      If videoSession was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR, then the pNext chain must include a VkVideoDecodeH265SessionParametersCreateInfoKHR structure

    • VUID-VkVideoSessionParametersCreateInfoKHR-videoSession-07207
      If videoSession was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR, then the number of elements of vpsAddList must be less than or equal to the maxStdVPSCount specified in the VkVideoDecodeH265SessionParametersCreateInfoKHR structure included in the pNext chain

    • VUID-VkVideoSessionParametersCreateInfoKHR-videoSession-07208
      If videoSession was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR, then the number of elements of spsAddList must be less than or equal to the maxStdSPSCount specified in the VkVideoDecodeH265SessionParametersCreateInfoKHR structure included in the pNext chain

    • VUID-VkVideoSessionParametersCreateInfoKHR-videoSession-07209
      If videoSession was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR, then the number of elements of ppsAddList must be less than or equal to the maxStdPPSCount specified in the VkVideoDecodeH265SessionParametersCreateInfoKHR structure included in the pNext chain

    Valid Usage (Implicit)

    • VUID-VkVideoSessionParametersCreateInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_SESSION_PARAMETERS_CREATE_INFO_KHR

    • VUID-VkVideoSessionParametersCreateInfoKHR-pNext-pNext
      Each pNext member of any structure (including this one) in the pNext chain must be either NULL or a pointer to a valid instance of VkVideoDecodeH264SessionParametersCreateInfoKHR or VkVideoDecodeH265SessionParametersCreateInfoKHR

    • VUID-VkVideoSessionParametersCreateInfoKHR-sType-unique
      The sType value of each struct in the pNext chain must be unique

    • VUID-VkVideoSessionParametersCreateInfoKHR-flags-zerobitmask
      flags must be 0

    • VUID-VkVideoSessionParametersCreateInfoKHR-videoSessionParametersTemplate-parameter
      If videoSessionParametersTemplate is not VK_NULL_HANDLE, videoSessionParametersTemplate must be a valid VkVideoSessionParametersKHR handle

    • VUID-VkVideoSessionParametersCreateInfoKHR-videoSession-parameter
      videoSession must be a valid VkVideoSessionKHR handle

    • VUID-VkVideoSessionParametersCreateInfoKHR-videoSessionParametersTemplate-parent
      If videoSessionParametersTemplate is a valid handle, it must have been created, allocated, or retrieved from videoSession

    • VUID-VkVideoSessionParametersCreateInfoKHR-commonparent
      Both of videoSession, and videoSessionParametersTemplate that are valid handles of non-ignored parameters must have been created, allocated, or retrieved from the same VkDevice

    // Provided by VK_KHR_video_queue
typedef VkFlags VkVideoSessionParametersCreateFlagsKHR;

    VkVideoSessionParametersCreateFlagsKHR is a bitmask type for setting a mask, but is currently reserved for future use.

    36.7.2. Destroying Video Session Parameters

    To destroy a video session parameters object, call:

    // Provided by VK_KHR_video_queue
void vkDestroyVideoSessionParametersKHR(
    VkDevice                                    device,
    VkVideoSessionParametersKHR                 videoSessionParameters,
    const VkAllocationCallbacks*                pAllocator);

    • device is the logical device that destroys the video session parameters object.

    • videoSessionParameters is the video session parameters object to destroy.

    • pAllocator controls host memory allocation as described in the Memory Allocation chapter.

    Valid Usage

    • VUID-vkDestroyVideoSessionParametersKHR-videoSessionParameters-07212
      All submitted commands that refer to videoSessionParameters must have completed execution

    • VUID-vkDestroyVideoSessionParametersKHR-videoSessionParameters-07213
      If VkAllocationCallbacks were provided when videoSessionParameters was created, a compatible set of callbacks must be provided here

    • VUID-vkDestroyVideoSessionParametersKHR-videoSessionParameters-07214
      If no VkAllocationCallbacks were provided when videoSessionParameters was created, pAllocator must be NULL

    Valid Usage (Implicit)

    • VUID-vkDestroyVideoSessionParametersKHR-device-parameter
      device must be a valid VkDevice handle

    • VUID-vkDestroyVideoSessionParametersKHR-videoSessionParameters-parameter
      If videoSessionParameters is not VK_NULL_HANDLE, videoSessionParameters must be a valid VkVideoSessionParametersKHR handle

    • VUID-vkDestroyVideoSessionParametersKHR-pAllocator-parameter
      If pAllocator is not NULL, pAllocator must be a valid pointer to a valid VkAllocationCallbacks structure

    Host Synchronization

    • Host access to videoSessionParameters must be externally synchronized

    36.7.3. Updating Video Session Parameters

    To update video session parameters object with new parameters, call:

    // Provided by VK_KHR_video_queue
VkResult vkUpdateVideoSessionParametersKHR(
    VkDevice                                    device,
    VkVideoSessionParametersKHR                 videoSessionParameters,
    const VkVideoSessionParametersUpdateInfoKHR* pUpdateInfo);

    • device is the logical device that updates the video session parameters.

    • videoSessionParameters is the video session parameters object to update.

    • pUpdateInfo is a pointer to a VkVideoSessionParametersUpdateInfoKHR structure specifying the parameter update information.

    After a successful call to this command, the update sequence counter of videoSessionParameters is changed to the value specified in pUpdateInfo->updateSequenceCount.

    Note:

    As each update issued to a video session parameters object needs to specify the next available update sequence count value, concurrent updates of the same video session parameters object are inherently disallowed. However, recording video coding operations to command buffers referring to parameters previously added to the video session parameters object is allowed, even if there is a concurrent update in progress adding some new entries to the object.

    If videoSessionParameters was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR and the pUpdateInfo->pNext chain includes a VkVideoDecodeH264SessionParametersAddInfoKHR structure, then this command adds the following parameter entries to videoSessionParameters:

    If videoSessionParameters was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR and the pUpdateInfo->pNext chain includes a VkVideoDecodeH265SessionParametersAddInfoKHR structure, then this command adds the following parameter entries to videoSessionParameters:

    In case of video session parameters objects created with a video encode operation, implementations may return the VK_ERROR_INVALID_VIDEO_STD_PARAMETERS_KHR error if any of the specified Video Std parameters do not adhere to the syntactic or semantic requirements of the used video compression standard, or if values derived from parameters according to the rules defined by the used video compression standard do not adhere to the capabilities of the video compression standard or the implementation.

    Note

    Applications should not rely on the VK_ERROR_INVALID_VIDEO_STD_PARAMETERS_KHR error being returned by any command as a means to verify Video Std parameters, as implementations are not required to report the error in any specific set of cases.
    Valid Usage

    • VUID-vkUpdateVideoSessionParametersKHR-pUpdateInfo-07215
      pUpdateInfo->updateSequenceCount must equal the current update sequence counter of videoSessionParameters plus one

    • VUID-vkUpdateVideoSessionParametersKHR-videoSessionParameters-07216
      If videoSessionParameters was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR and the pNext chain of pUpdateInfo includes a VkVideoDecodeH264SessionParametersAddInfoKHR structure, then videoSessionParameters must not already contain a StdVideoH264SequenceParameterSet entry with seq_parameter_set_id matching any of the elements of VkVideoDecodeH264SessionParametersAddInfoKHR::pStdSPSs

    • VUID-vkUpdateVideoSessionParametersKHR-videoSessionParameters-07217
      If videoSessionParameters was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR, then the number of StdVideoH264SequenceParameterSet entries already stored in it plus the value of the stdSPSCount member of the VkVideoDecodeH264SessionParametersAddInfoKHR structure included in the pUpdateInfo->pNext chain must be less than or equal to the VkVideoDecodeH264SessionParametersCreateInfoKHR::maxStdSPSCount videoSessionParameters was created with

    • VUID-vkUpdateVideoSessionParametersKHR-videoSessionParameters-07218
      If videoSessionParameters was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR and the pNext chain of pUpdateInfo includes a VkVideoDecodeH264SessionParametersAddInfoKHR structure, then videoSessionParameters must not already contain a StdVideoH264PictureParameterSet entry with both seq_parameter_set_id and pic_parameter_set_id matching any of the elements of VkVideoDecodeH264SessionParametersAddInfoKHR::pStdPPSs

    • VUID-vkUpdateVideoSessionParametersKHR-videoSessionParameters-07219
      If videoSessionParameters was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR, then the number of StdVideoH264PictureParameterSet entries already stored in it plus the value of the stdPPSCount member of the VkVideoDecodeH264SessionParametersAddInfoKHR structure included in the pUpdateInfo->pNext chain must be less than or equal to the VkVideoDecodeH264SessionParametersCreateInfoKHR::maxStdPPSCount videoSessionParameters was created with

    • VUID-vkUpdateVideoSessionParametersKHR-videoSessionParameters-07220
      If videoSessionParameters was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR and the pNext chain of pUpdateInfo includes a VkVideoDecodeH265SessionParametersAddInfoKHR structure, then videoSessionParameters must not already contain a StdVideoH265VideoParameterSet entry with vps_video_parameter_set_id matching any of the elements of VkVideoDecodeH265SessionParametersAddInfoKHR::pStdVPSs

    • VUID-vkUpdateVideoSessionParametersKHR-videoSessionParameters-07221
      If videoSessionParameters was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR, then the number of StdVideoH265VideoParameterSet entries already stored in it plus the value of the stdVPSCount member of the VkVideoDecodeH265SessionParametersAddInfoKHR structure included in the pUpdateInfo->pNext chain must be less than or equal to the VkVideoDecodeH265SessionParametersCreateInfoKHR::maxStdVPSCount videoSessionParameters was created with

    • VUID-vkUpdateVideoSessionParametersKHR-videoSessionParameters-07222
      If videoSessionParameters was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR and the pNext chain of pUpdateInfo includes a VkVideoDecodeH265SessionParametersAddInfoKHR structure, then videoSessionParameters must not already contain a StdVideoH265SequenceParameterSet entry with both sps_video_parameter_set_id and sps_seq_parameter_set_id matching any of the elements of VkVideoDecodeH265SessionParametersAddInfoKHR::pStdSPSs

    • VUID-vkUpdateVideoSessionParametersKHR-videoSessionParameters-07223
      If videoSessionParameters was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR, then the number of StdVideoH265SequenceParameterSet entries already stored in it plus the value of the stdSPSCount member of the VkVideoDecodeH265SessionParametersAddInfoKHR structure included in the pUpdateInfo->pNext chain must be less than or equal to the VkVideoDecodeH265SessionParametersCreateInfoKHR::maxStdSPSCount videoSessionParameters was created with

    • VUID-vkUpdateVideoSessionParametersKHR-videoSessionParameters-07224
      If videoSessionParameters was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR and the pNext chain of pUpdateInfo includes a VkVideoDecodeH265SessionParametersAddInfoKHR structure, then videoSessionParameters must not already contain a StdVideoH265PictureParameterSet entry with sps_video_parameter_set_id, pps_seq_parameter_set_id, and pps_pic_parameter_set_id all matching any of the elements of VkVideoDecodeH265SessionParametersAddInfoKHR::pStdPPSs

    • VUID-vkUpdateVideoSessionParametersKHR-videoSessionParameters-07225
      If videoSessionParameters was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR, then the number of StdVideoH265PictureParameterSet entries already stored in it plus the value of the stdPPSCount member of the VkVideoDecodeH265SessionParametersAddInfoKHR structure included in the pUpdateInfo->pNext chain must be less than or equal to the VkVideoDecodeH265SessionParametersCreateInfoKHR::maxStdPPSCount videoSessionParameters was created with

    Valid Usage (Implicit)

    • VUID-vkUpdateVideoSessionParametersKHR-device-parameter
      device must be a valid VkDevice handle

    • VUID-vkUpdateVideoSessionParametersKHR-videoSessionParameters-parameter
      videoSessionParameters must be a valid VkVideoSessionParametersKHR handle

    • VUID-vkUpdateVideoSessionParametersKHR-pUpdateInfo-parameter
      pUpdateInfo must be a valid pointer to a valid VkVideoSessionParametersUpdateInfoKHR structure

    Return Codes
    Success

    • VK_SUCCESS

    Failure

    • VK_ERROR_OUT_OF_HOST_MEMORY

    • VK_ERROR_OUT_OF_DEVICE_MEMORY

    • VK_ERROR_INVALID_VIDEO_STD_PARAMETERS_KHR

    The VkVideoSessionParametersUpdateInfoKHR structure is defined as:

    // Provided by VK_KHR_video_queue
typedef struct VkVideoSessionParametersUpdateInfoKHR {
    VkStructureType    sType;
    const void*        pNext;
    uint32_t           updateSequenceCount;
} VkVideoSessionParametersUpdateInfoKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • updateSequenceCount is the new update sequence count to set for the video session parameters object.

    Valid Usage (Implicit)

    • VUID-VkVideoSessionParametersUpdateInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_SESSION_PARAMETERS_UPDATE_INFO_KHR

    • VUID-VkVideoSessionParametersUpdateInfoKHR-pNext-pNext
      Each pNext member of any structure (including this one) in the pNext chain must be either NULL or a pointer to a valid instance of VkVideoDecodeH264SessionParametersAddInfoKHR or VkVideoDecodeH265SessionParametersAddInfoKHR

    • VUID-VkVideoSessionParametersUpdateInfoKHR-sType-unique
      The sType value of each struct in the pNext chain must be unique

    36.8. Video Coding Scope

    Applications can record video coding commands for a video session only within a video coding scope.

    To begin a video coding scope, call:

    // Provided by VK_KHR_video_queue
void vkCmdBeginVideoCodingKHR(
    VkCommandBuffer                             commandBuffer,
    const VkVideoBeginCodingInfoKHR*            pBeginInfo);

    • commandBuffer is the command buffer in which to record the command.

    • pBeginInfo is a pointer to a VkVideoBeginCodingInfoKHR structure specifying the parameters of the video coding scope, including the video session and video session parameters object to use.

    After beginning a video coding scope, the video session object specified in pBeginInfo->videoSession is bound to the command buffer, and the command buffer is ready to record video coding operations. Similarly, if pBeginInfo->videoSessionParameters is not VK_NULL_HANDLE, it is also bound to the command buffer, and video coding operations can refer to the codec-specific parameters stored in it.

    This command also establishes the set of bound reference picture resources that can be used as reconstructed pictures or reference pictures within the video coding scope. Each element of this set consists of a video picture resource and the DPB slot index associated with it, if there is one.

    The set of bound reference picture resources is immutable within a video coding scope, however, the DPB slot index associated with any of the bound reference picture resources can change during the video coding scope in response to video coding operations.

    The VkVideoReferenceSlotInfoKHR structures provided as the elements of pBeginInfo->pReferenceSlots are interpreted by this command as follows:

    • If slotIndex is non-negative and pPictureResource is not NULL, then the video picture resource defined by the VkVideoPictureResourceInfoKHR structure pointed to by pPictureResource is added to the set of bound reference picture resources and is associated with the DPB slot index specified in slotIndex.

    • If slotIndex is non-negative and pPictureResource is NULL, then the DPB slot with index slotIndex is deactivated by this command.

    • If slotIndex is negative and pPictureResource is not NULL, then the video picture resource defined by the VkVideoPictureResourceInfoKHR structure pointed to by pPictureResource is added to the set of bound reference picture resources without an associated DPB slot. Such a picture resource can be subsequently used as a reconstructed picture to associate it with a DPB slot.

    • If slotIndex is negative and pPictureResource is NULL, then the element is ignored.

    Note:

    It is possible for multiple bound reference picture resources to be associated with the same DPB slot index, or for a single bound reference picture to refer to multiple separate reference pictures. For example, in case of an H.264 decode profile with interlaced frame support a single DPB slot can refer to two separate pictures for the top and bottom fields. Depending on the picture layout used by the H.264 decode profile, the following special cases may arise:

    • If the picture layout is VK_VIDEO_DECODE_H264_PICTURE_LAYOUT_INTERLACED_INTERLEAVED_LINES_BIT_KHR, then the top and bottom field pictures are physically co-located in the same video picture resource with even scanlines corresponding to the top field and odd scanlines corresponding to the bottom field, respectively.

    • If the picture layout is VK_VIDEO_DECODE_H264_PICTURE_LAYOUT_INTERLACED_SEPARATE_PLANES_BIT_KHR, then the top and bottom field pictures are stored in separate video picture resources (in separate subregions of the same image layer, in separate layers of the same image, or in entirely separate images), hence two elements of VkVideoBeginCodingInfoKHR::pReferenceSlots can contain the same slotIndex but specify different video picture resources in their pPictureResource members.

    All non-negative slotIndex values specified in the elements of pBeginInfo->pReferenceSlots must identify DPB slots of the video session that are in the active state at the time this command is executed on the device.

    Note:

    The application does not have to specify an entry in pBeginInfo->pReferenceSlots corresponding to all active DPB slots of the video session, but only for those which are intended to be used in the video coding scope. This way the application can avoid any potential runtime cost associated with binding the corresponding picture resources to the command buffer.
    Valid Usage

    • VUID-vkCmdBeginVideoCodingKHR-commandBuffer-07231
      The VkCommandPool that commandBuffer was allocated from must support the video codec operation pBeginInfo->videoSession was created with, as returned by vkGetPhysicalDeviceQueueFamilyProperties2 in VkQueueFamilyVideoPropertiesKHR::videoCodecOperations

    • VUID-vkCmdBeginVideoCodingKHR-None-07232
      There must be no active queries

    • VUID-vkCmdBeginVideoCodingKHR-commandBuffer-07233
      If commandBuffer is an unprotected command buffer and protectedNoFault is not supported, then pBeginInfo->videoSession must not have been created with VK_VIDEO_SESSION_CREATE_PROTECTED_CONTENT_BIT_KHR

    • VUID-vkCmdBeginVideoCodingKHR-commandBuffer-07234
      If commandBuffer is a protected command buffer and protectedNoFault is not supported, then pBeginInfo->videoSession must have been created with VK_VIDEO_SESSION_CREATE_PROTECTED_CONTENT_BIT_KHR

    • VUID-vkCmdBeginVideoCodingKHR-commandBuffer-07235
      If commandBuffer is an unprotected command buffer, protectedNoFault is not supported, and the pPictureResource member of any element of pBeginInfo->pReferenceSlots is not NULL, then pPictureResource->imageViewBinding for that element must not specify an image view created from a protected image

    • VUID-vkCmdBeginVideoCodingKHR-commandBuffer-07236
      If commandBuffer is a protected command buffer protectedNoFault is not supported, and the pPictureResource member of any element of pBeginInfo->pReferenceSlots is not NULL, then pPictureResource->imageViewBinding for that element must specify an image view created from a protected image

    • VUID-vkCmdBeginVideoCodingKHR-slotIndex-07239
      If the slotIndex member of any element of pBeginInfo->pReferenceSlots is not negative, then it must specify the index of a DPB slot that is in the active state in pBeginInfo->videoSession at the time the command is executed on the device

    • VUID-vkCmdBeginVideoCodingKHR-pPictureResource-07265
      Each video picture resource specified by any non-NULL pPictureResource member specified in the elements of pBeginInfo->pReferenceSlots for which slotIndex is not negative must match one of the video picture resources currently associated with the DPB slot index of pBeginInfo->videoSession specified by slotIndex at the time the command is executed on the device

    Valid Usage (Implicit)

    • VUID-vkCmdBeginVideoCodingKHR-commandBuffer-parameter
      commandBuffer must be a valid VkCommandBuffer handle

    • VUID-vkCmdBeginVideoCodingKHR-pBeginInfo-parameter
      pBeginInfo must be a valid pointer to a valid VkVideoBeginCodingInfoKHR structure

    • VUID-vkCmdBeginVideoCodingKHR-commandBuffer-recording
      commandBuffer must be in the recording state

    • VUID-vkCmdBeginVideoCodingKHR-commandBuffer-cmdpool
      The VkCommandPool that commandBuffer was allocated from must support decode, or encode operations

    • VUID-vkCmdBeginVideoCodingKHR-renderpass
      This command must only be called outside of a render pass instance

    • VUID-vkCmdBeginVideoCodingKHR-videocoding
      This command must only be called outside of a video coding scope

    • VUID-vkCmdBeginVideoCodingKHR-bufferlevel
      commandBuffer must be a primary VkCommandBuffer

    Host Synchronization

    • Host access to commandBuffer must be externally synchronized

    • Host access to the VkCommandPool that commandBuffer was allocated from must be externally synchronized

    Command Properties
    Command Buffer Levels Render Pass Scope Video Coding Scope Supported Queue Types Command Type

    Primary

    Outside

    Outside

    Decode
    Encode

    Action
    State

    The VkVideoBeginCodingInfoKHR structure is defined as:

    // Provided by VK_KHR_video_queue
typedef struct VkVideoBeginCodingInfoKHR {
    VkStructureType                       sType;
    const void*                           pNext;
    VkVideoBeginCodingFlagsKHR            flags;
    VkVideoSessionKHR                     videoSession;
    VkVideoSessionParametersKHR           videoSessionParameters;
    uint32_t                              referenceSlotCount;
    const VkVideoReferenceSlotInfoKHR*    pReferenceSlots;
} VkVideoBeginCodingInfoKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • flags is reserved for future use.

    • videoSession is the video session object to be bound for the processing of the video commands.

    • videoSessionParameters is VK_NULL_HANDLE or a handle of a VkVideoSessionParametersKHR object to be used for the processing of the video commands. If VK_NULL_HANDLE, then no video session parameters object is bound for the duration of the video coding scope.

    • referenceSlotCount is the number of elements in the pReferenceSlots array.

    • pReferenceSlots is a pointer to an array of VkVideoReferenceSlotInfoKHR structures specifying the information used to determine the set of bound reference picture resources for the video coding scope and their initial association with DPB slot indices.

    Limiting values are defined below that are referenced by the relevant valid usage statements of this structure.

    Valid Usage

    • VUID-VkVideoBeginCodingInfoKHR-videoSession-07237
      videoSession must have memory bound to all of its memory bindings returned by vkGetVideoSessionMemoryRequirementsKHR for videoSession

    • VUID-VkVideoBeginCodingInfoKHR-slotIndex-04856
      Each non-negative VkVideoReferenceSlotInfoKHR::slotIndex specified in the elements of pReferenceSlots must be less than the VkVideoSessionCreateInfoKHR::maxDpbSlots specified when videoSession was created

    • VUID-VkVideoBeginCodingInfoKHR-pPictureResource-07238
      Each video picture resource corresponding to any non-NULL pPictureResource member specified in the elements of pReferenceSlots must be unique within pReferenceSlots

    • VUID-VkVideoBeginCodingInfoKHR-pPictureResource-07240
      If the pPictureResource member of any element of pReferenceSlots is not NULL, then the image view specified in pPictureResource->imageViewBinding for that element must be compatible with the video profile videoSession was created with

    • VUID-VkVideoBeginCodingInfoKHR-pPictureResource-07241
      If the pPictureResource member of any element of pReferenceSlots is not NULL, then the format of the image view specified in pPictureResource->imageViewBinding for that element must match the VkVideoSessionCreateInfoKHR::referencePictureFormat videoSession was created with

    • VUID-VkVideoBeginCodingInfoKHR-pPictureResource-07242
      If the pPictureResource member of any element of pReferenceSlots is not NULL, then its codedOffset member must be an integer multiple of codedOffsetGranularity

    • VUID-VkVideoBeginCodingInfoKHR-pPictureResource-07243
      If the pPictureResource member of any element of pReferenceSlots is not NULL, then its codedExtent member must be between minCodedExtent and maxCodedExtent, inclusive, videoSession was created with

    • VUID-VkVideoBeginCodingInfoKHR-flags-07244
      If VkVideoCapabilitiesKHR::flags does not include VK_VIDEO_CAPABILITY_SEPARATE_REFERENCE_IMAGES_BIT_KHR, as returned by vkGetPhysicalDeviceVideoCapabilitiesKHR for the video profile videoSession was created with, then pPictureResource->imageViewBinding of all elements of pReferenceSlots with a non-NULL pPictureResource member must specify image views created from the same image

    • VUID-VkVideoBeginCodingInfoKHR-slotIndex-07245
      If videoSession was created with a decode operation and the slotIndex member of any element of pReferenceSlots is not negative, then the image view specified in pPictureResource->imageViewBinding for that element must have been created with VK_IMAGE_USAGE_VIDEO_DECODE_DPB_BIT_KHR

    • VUID-VkVideoBeginCodingInfoKHR-slotIndex-07246
      If videoSession was created with an encode operation and the slotIndex member of any element of pReferenceSlots is not negative, then the image view specified in pPictureResource->imageViewBinding for that element must have been created with VK_IMAGE_USAGE_VIDEO_ENCODE_DPB_BIT_KHR

    • VUID-VkVideoBeginCodingInfoKHR-videoSession-07247
      If videoSession was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR, then videoSessionParameters must not be VK_NULL_HANDLE

    • VUID-VkVideoBeginCodingInfoKHR-videoSession-07248
      If videoSession was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR, then videoSessionParameters must not be VK_NULL_HANDLE

    • VUID-VkVideoBeginCodingInfoKHR-videoSessionParameters-04857
      If videoSessionParameters is not VK_NULL_HANDLE, it must have been created with videoSession specified in VkVideoSessionParametersCreateInfoKHR::videoSession

    Valid Usage (Implicit)

    • VUID-VkVideoBeginCodingInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_BEGIN_CODING_INFO_KHR

    • VUID-VkVideoBeginCodingInfoKHR-pNext-pNext
      pNext must be NULL

    • VUID-VkVideoBeginCodingInfoKHR-flags-zerobitmask
      flags must be 0

    • VUID-VkVideoBeginCodingInfoKHR-videoSession-parameter
      videoSession must be a valid VkVideoSessionKHR handle

    • VUID-VkVideoBeginCodingInfoKHR-videoSessionParameters-parameter
      If videoSessionParameters is not VK_NULL_HANDLE, videoSessionParameters must be a valid VkVideoSessionParametersKHR handle

    • VUID-VkVideoBeginCodingInfoKHR-pReferenceSlots-parameter
      If referenceSlotCount is not 0, pReferenceSlots must be a valid pointer to an array of referenceSlotCount valid VkVideoReferenceSlotInfoKHR structures

    • VUID-VkVideoBeginCodingInfoKHR-videoSessionParameters-parent
      If videoSessionParameters is a valid handle, it must have been created, allocated, or retrieved from videoSession

    • VUID-VkVideoBeginCodingInfoKHR-commonparent
      Both of videoSession, and videoSessionParameters that are valid handles of non-ignored parameters must have been created, allocated, or retrieved from the same VkDevice

    // Provided by VK_KHR_video_queue
typedef VkFlags VkVideoBeginCodingFlagsKHR;

    VkVideoBeginCodingFlagsKHR is a bitmask type for setting a mask, but is currently reserved for future use.

    The VkVideoReferenceSlotInfoKHR structure is defined as:

    // Provided by VK_KHR_video_queue
typedef struct VkVideoReferenceSlotInfoKHR {
    VkStructureType                         sType;
    const void*                             pNext;
    int32_t                                 slotIndex;
    const VkVideoPictureResourceInfoKHR*    pPictureResource;
} VkVideoReferenceSlotInfoKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • slotIndex is the index of the DPB slot or a negative integer value.

    • pPictureResource is NULL or a pointer to a VkVideoPictureResourceInfoKHR structure describing the video picture resource associated with the DPB slot index specified by slotIndex.

    Valid Usage (Implicit)

    • VUID-VkVideoReferenceSlotInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_REFERENCE_SLOT_INFO_KHR

    • VUID-VkVideoReferenceSlotInfoKHR-pNext-pNext
      Each pNext member of any structure (including this one) in the pNext chain must be either NULL or a pointer to a valid instance of VkVideoDecodeH264DpbSlotInfoKHR or VkVideoDecodeH265DpbSlotInfoKHR

    • VUID-VkVideoReferenceSlotInfoKHR-sType-unique
      The sType value of each struct in the pNext chain must be unique

    • VUID-VkVideoReferenceSlotInfoKHR-pPictureResource-parameter
      If pPictureResource is not NULL, pPictureResource must be a valid pointer to a valid VkVideoPictureResourceInfoKHR structure

    To end a video coding scope, call:

    // Provided by VK_KHR_video_queue
void vkCmdEndVideoCodingKHR(
    VkCommandBuffer                             commandBuffer,
    const VkVideoEndCodingInfoKHR*              pEndCodingInfo);

    • commandBuffer is the command buffer in which to record the command.

    • pEndCodingInfo is a pointer to a VkVideoEndCodingInfoKHR structure specifying the parameters for ending the video coding scope.

    After ending a video coding scope, the video session object, the optional video session parameters object, and all reference picture resources previously bound by the corresponding vkCmdBeginVideoCodingKHR command are unbound.

    Valid Usage

    • VUID-vkCmdEndVideoCodingKHR-None-07251
      There must be no active queries

    Valid Usage (Implicit)

    • VUID-vkCmdEndVideoCodingKHR-commandBuffer-parameter
      commandBuffer must be a valid VkCommandBuffer handle

    • VUID-vkCmdEndVideoCodingKHR-pEndCodingInfo-parameter
      pEndCodingInfo must be a valid pointer to a valid VkVideoEndCodingInfoKHR structure

    • VUID-vkCmdEndVideoCodingKHR-commandBuffer-recording
      commandBuffer must be in the recording state

    • VUID-vkCmdEndVideoCodingKHR-commandBuffer-cmdpool
      The VkCommandPool that commandBuffer was allocated from must support decode, or encode operations

    • VUID-vkCmdEndVideoCodingKHR-renderpass
      This command must only be called outside of a render pass instance

    • VUID-vkCmdEndVideoCodingKHR-videocoding
      This command must only be called inside of a video coding scope

    • VUID-vkCmdEndVideoCodingKHR-bufferlevel
      commandBuffer must be a primary VkCommandBuffer

    Host Synchronization

    • Host access to commandBuffer must be externally synchronized

    • Host access to the VkCommandPool that commandBuffer was allocated from must be externally synchronized

    Command Properties
    Command Buffer Levels Render Pass Scope Video Coding Scope Supported Queue Types Command Type

    Primary

    Outside

    Inside

    Decode
    Encode

    Action
    State

    The VkVideoEndCodingInfoKHR structure is defined as:

    // Provided by VK_KHR_video_queue
typedef struct VkVideoEndCodingInfoKHR {
    VkStructureType             sType;
    const void*                 pNext;
    VkVideoEndCodingFlagsKHR    flags;
} VkVideoEndCodingInfoKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • flags is reserved for future use.

    Valid Usage (Implicit)

    • VUID-VkVideoEndCodingInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_END_CODING_INFO_KHR

    • VUID-VkVideoEndCodingInfoKHR-pNext-pNext
      pNext must be NULL

    • VUID-VkVideoEndCodingInfoKHR-flags-zerobitmask
      flags must be 0

    // Provided by VK_KHR_video_queue
typedef VkFlags VkVideoEndCodingFlagsKHR;

    VkVideoEndCodingFlagsKHR is a bitmask type for setting a mask, but is currently reserved for future use.

    36.9. Video Coding Control

    To apply dynamic controls to the currently bound video session object, call:

    // Provided by VK_KHR_video_queue
void vkCmdControlVideoCodingKHR(
    VkCommandBuffer                             commandBuffer,
    const VkVideoCodingControlInfoKHR*          pCodingControlInfo);

    • commandBuffer is the command buffer in which to record the command.

    • pCodingControlInfo is a pointer to a VkVideoCodingControlInfoKHR structure specifying the control parameters.

    The control parameters provided in this call are applied to the video session at the time the command executes on the device and are in effect until a subsequent call to this command with the same video session bound changes the corresponding control parameters.

    A newly created video session must be reset before performing video coding operations using it by including VK_VIDEO_CODING_CONTROL_RESET_BIT_KHR in pCodingControlInfo->flags. The reset operation also returns all DPB slots of the video session to the inactive state. Correspondingly, any DPB slot index associated with the bound reference picture resources is removed.

    For encode sessions, the reset operation returns rate control configuration to implementation default settings.

    After video coding operations are performed using a video session, the reset operation can be used to return the video session to the same initial state as after the reset of a newly created video session. This can be used, for example, when different video sequences are needed to be processed with the same video session object.

    Valid Usage

    • VUID-vkCmdControlVideoCodingKHR-flags-07017
      If pCodingControlInfo->flags does not include VK_VIDEO_CODING_CONTROL_RESET_BIT_KHR, then the bound video session must not be in uninitialized state at the time the command is executed on the device

    Valid Usage (Implicit)

    • VUID-vkCmdControlVideoCodingKHR-commandBuffer-parameter
      commandBuffer must be a valid VkCommandBuffer handle

    • VUID-vkCmdControlVideoCodingKHR-pCodingControlInfo-parameter
      pCodingControlInfo must be a valid pointer to a valid VkVideoCodingControlInfoKHR structure

    • VUID-vkCmdControlVideoCodingKHR-commandBuffer-recording
      commandBuffer must be in the recording state

    • VUID-vkCmdControlVideoCodingKHR-commandBuffer-cmdpool
      The VkCommandPool that commandBuffer was allocated from must support decode, or encode operations

    • VUID-vkCmdControlVideoCodingKHR-renderpass
      This command must only be called outside of a render pass instance

    • VUID-vkCmdControlVideoCodingKHR-videocoding
      This command must only be called inside of a video coding scope

    • VUID-vkCmdControlVideoCodingKHR-bufferlevel
      commandBuffer must be a primary VkCommandBuffer

    Host Synchronization

    • Host access to commandBuffer must be externally synchronized

    • Host access to the VkCommandPool that commandBuffer was allocated from must be externally synchronized

    Command Properties
    Command Buffer Levels Render Pass Scope Video Coding Scope Supported Queue Types Command Type

    Primary

    Outside

    Inside

    Decode
    Encode

    Action

    The VkVideoCodingControlInfoKHR structure is defined as:

    // Provided by VK_KHR_video_queue
typedef struct VkVideoCodingControlInfoKHR {
    VkStructureType                 sType;
    const void*                     pNext;
    VkVideoCodingControlFlagsKHR    flags;
} VkVideoCodingControlInfoKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • flags is a bitmask of VkVideoCodingControlFlagsKHR specifying control flags.

    Valid Usage

    • VUID-VkVideoCodingControlInfoKHR-flags-07018
      If flags includes VK_VIDEO_CODING_CONTROL_ENCODE_RATE_CONTROL_BIT_KHR, then the pNext chain must include a VkVideoEncodeRateControlInfoKHR structure

    • VUID-VkVideoCodingControlInfoKHR-flags-07019
      If flags includes VK_VIDEO_CODING_CONTROL_ENCODE_RATE_CONTROL_LAYER_BIT_KHR, then the pNext chain must include a VkVideoEncodeRateControlLayerInfoKHR structure

    • VUID-VkVideoCodingControlInfoKHR-flags-07020
      If flags includes VK_VIDEO_CODING_CONTROL_ENCODE_RATE_CONTROL_BIT_KHR, then it must not also include VK_VIDEO_CODING_CONTROL_ENCODE_RATE_CONTROL_LAYER_BIT_KHR

    Valid Usage (Implicit)

    • VUID-VkVideoCodingControlInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_CODING_CONTROL_INFO_KHR

    • VUID-VkVideoCodingControlInfoKHR-pNext-pNext
      Each pNext member of any structure (including this one) in the pNext chain must be either NULL or a pointer to a valid instance of VkVideoEncodeRateControlInfoKHR or VkVideoEncodeRateControlLayerInfoKHR

    • VUID-VkVideoCodingControlInfoKHR-sType-unique
      The sType value of each struct in the pNext chain must be unique

    • VUID-VkVideoCodingControlInfoKHR-flags-parameter
      flags must be a valid combination of VkVideoCodingControlFlagBitsKHR values

    • VUID-VkVideoCodingControlInfoKHR-flags-requiredbitmask
      flags must not be 0

    Bits which can be set in VkVideoCodingControlInfoKHR::flags, specifying the video coding control parameters to be modified, are:

    // Provided by VK_KHR_video_queue
typedef enum VkVideoCodingControlFlagBitsKHR {
    VK_VIDEO_CODING_CONTROL_RESET_BIT_KHR = 0x00000001,
#ifdef VK_ENABLE_BETA_EXTENSIONS
  // Provided by VK_KHR_video_encode_queue
    VK_VIDEO_CODING_CONTROL_ENCODE_RATE_CONTROL_BIT_KHR = 0x00000002,
#endif
#ifdef VK_ENABLE_BETA_EXTENSIONS
  // Provided by VK_KHR_video_encode_queue
    VK_VIDEO_CODING_CONTROL_ENCODE_RATE_CONTROL_LAYER_BIT_KHR = 0x00000004,
#endif
} VkVideoCodingControlFlagBitsKHR;

    • VK_VIDEO_CODING_CONTROL_RESET_BIT_KHR indicates a request for the bound video session to be reset before other coding control parameters are applied.

    • VK_VIDEO_CODING_CONTROL_ENCODE_RATE_CONTROL_BIT_KHR indicates that the coding control parameters include video encode rate control parameters (see VkVideoEncodeRateControlInfoKHR).

    • VK_VIDEO_CODING_CONTROL_ENCODE_RATE_CONTROL_LAYER_BIT_KHR indicates that the coding control parameters include video encode rate control layer parameters (see VkVideoEncodeRateControlLayerInfoKHR).

    // Provided by VK_KHR_video_queue
typedef VkFlags VkVideoCodingControlFlagsKHR;

    VkVideoCodingControlFlagsKHR is a bitmask type for setting a mask of zero or more VkVideoCodingControlFlagBitsKHR.

    36.10. Video Decode Operations

    Video decode operations consume compressed video data from a video bitstream buffer and zero or more reference pictures, and produce a decode output picture and an optional reconstructed picture.

    Note:

    Such decode output pictures can be shared with the Decoded Picture Buffer, and can also be used as the input of video encode operations, with graphics or compute operations, or with Window System Integration APIs, depending on the capabilities of the implementation.

    Video decode operations may access the following resources in the VK_PIPELINE_STAGE_2_VIDEO_DECODE_BIT_KHR stage:

    The image subresource of each video picture resource accessed by the video coding operation is specified using a corresponding VkVideoPictureResourceInfoKHR structure. Each such image subresource must be in the appropriate image layout as follows:

    • If the image subresource is used in the video decode operation only as decode output picture, then it must be in the VK_IMAGE_LAYOUT_VIDEO_DECODE_DST_KHR layout.

    • If the image subresource is used in the video decode operation both as decode output picture and reconstructed picture, then it must be in the VK_IMAGE_LAYOUT_VIDEO_DECODE_DPB_KHR layout.

    • If the image subresource is used in the video decode operation only as reconstructed picture, then it must be in the VK_IMAGE_LAYOUT_VIDEO_DECODE_DPB_KHR layout.

    • If the image subresource is used in the video decode operation as a reference picture, then it must be in the VK_IMAGE_LAYOUT_VIDEO_DECODE_DPB_KHR layout.

    A video decode operation may complete unsuccessfully. In this case the decode output picture will have undefined contents. Similarly, if a reconstructed picture is specified, it will also have undefined contents, and the activated DPB slot will have an invalid picture reference.

    36.10.1. Codec-Specific Semantics

    The following aspects of video decode operations are codec-specific:

    • The interpretation of the contents of the source video bitstream buffer range.

    • The construction and interpretation of the list of active reference pictures and the interpretation of the picture data referred to by the corresponding image subregions.

    • The construction and interpretation of information related to the decode output picture and the generation of picture data to the corresponding image subregion.

    • The construction and interpretation of information related to the optional reconstructed picture and the generation of picture data to the corresponding image subregion.

    These codec-specific behaviors are defined for each video codec operation separately.

    • If the used video codec operation is VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR, then the codec-specific aspects of the video decoding process are performed as defined in the H.264 Decode Operations section.

    • If the used video codec operation is VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR, then the codec-specific aspects of the video decoding process are performed as defined in the H.265 Decode Operations section.

    36.10.2. Video Decode Operation Steps

    Each video decode operation performs the following steps in the VK_PIPELINE_STAGE_2_VIDEO_DECODE_BIT_KHR stage:

    1. Reads the encoded video data from the source video bitstream buffer range.

    2. Performs picture reconstruction of the encoded video data according to the codec-specific semantics, applying any prediction data read from the active reference pictures in the process;

    3. Writes the decoded picture data to the decode output picture, and to the reconstructed picture, if one is specified and is different from the decode output picture, according to the codec-specific semantics;

    4. When reconstructed picture information is provided, the requested DPB slot is activated with the specified picture and the DPB slot index is associated with the corresponding bound reference picture resource.

    36.10.3. Capabilities

    When calling vkGetPhysicalDeviceVideoCapabilitiesKHR with pVideoProfile->videoCodecOperation specifying a decode operation, the VkVideoDecodeCapabilitiesKHR structure must be included in the pNext chain of the VkVideoCapabilitiesKHR structure to retrieve capabilities specific to video decoding.

    The VkVideoDecodeCapabilitiesKHR structure is defined as:

    // Provided by VK_KHR_video_decode_queue
typedef struct VkVideoDecodeCapabilitiesKHR {
    VkStructureType                    sType;
    void*                              pNext;
    VkVideoDecodeCapabilityFlagsKHR    flags;
} VkVideoDecodeCapabilitiesKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • flags is a bitmask of VkVideoDecodeCapabilityFlagBitsKHR describing the supported video decoding capabilities.

    Valid Usage (Implicit)

    • VUID-VkVideoDecodeCapabilitiesKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_DECODE_CAPABILITIES_KHR

    Bits which may be set in VkVideoDecodeCapabilitiesKHR::flags, indicating the decoding capabilities supported, are:

    // Provided by VK_KHR_video_decode_queue
typedef enum VkVideoDecodeCapabilityFlagBitsKHR {
    VK_VIDEO_DECODE_CAPABILITY_DPB_AND_OUTPUT_COINCIDE_BIT_KHR = 0x00000001,
    VK_VIDEO_DECODE_CAPABILITY_DPB_AND_OUTPUT_DISTINCT_BIT_KHR = 0x00000002,
} VkVideoDecodeCapabilityFlagBitsKHR;

    Implementations are only required to support one of VK_VIDEO_DECODE_CAPABILITY_DPB_AND_OUTPUT_COINCIDE_BIT_KHR and VK_VIDEO_DECODE_CAPABILITY_DPB_AND_OUTPUT_DISTINCT_BIT_KHR. Accordingly, applications should handle both cases to maximize portability.

    Note:

    If both VK_VIDEO_DECODE_CAPABILITY_DPB_AND_OUTPUT_COINCIDE_BIT_KHR and VK_VIDEO_DECODE_CAPABILITY_DPB_AND_OUTPUT_DISTINCT_BIT_KHR are supported, an application can choose to create separate images for decode DPB and decode output. E.g. in cases when linear tiling is preferred (and supported) for the decode output picture and the DPB requires optimal tiling, this avoids the need for a separate copy at the expense of additional memory bandwidth requirements during decoding.

    		 
    // Provided by VK_KHR_video_decode_queue
typedef VkFlags VkVideoDecodeCapabilityFlagsKHR;

    VkVideoDecodeCapabilityFlagsKHR is a bitmask type for setting a mask of zero or more VkVideoDecodeCapabilityFlagBitsKHR.

    36.10.4. Video Decode Commands

    To launch video decode operations, call:

    // Provided by VK_KHR_video_decode_queue
void vkCmdDecodeVideoKHR(
    VkCommandBuffer                             commandBuffer,
    const VkVideoDecodeInfoKHR*                 pDecodeInfo);

    • commandBuffer is the command buffer in which to record the command.

    • pDecodeInfo is a pointer to a VkVideoDecodeInfoKHR structure specifying the parameters of the video decode operations.

    Each call issues one or more video decode operations. The implicit parameter opCount corresponds to the number of video decode operations issued by the command. After calling this command, the active query index of each active query is incremented by opCount.

    Currently each call to this command results in the issue of a single video decode operation.

    Active Reference Picture Information

    The list of active reference pictures used by a video decode operation is a list of image subregions used as the source of reference picture data and related parameters, and is derived from the VkVideoReferenceSlotInfoKHR structures provided as the elements of the pDecodeInfo->pReferenceSlots array. For each element of pDecodeInfo->pReferenceSlots, one or more elements are added to the active reference picture list, as defined by the codec-specific semantics. Each element of this list contains the following information:

    • The image subregion within the image subresource referred to by the video picture resource used as the reference picture.

    • The DPB slot index the reference picture is associated with.

    • The codec-specific reference information related to the reference picture.

    Reconstructed Picture Information

    Information related to the optional reconstructed picture used by a video decode operation is derived from the VkVideoReferenceSlotInfoKHR structure pointed to by pDecodeInfo->pSetupReferenceSlot, if not NULL, as defined by the codec-specific semantics, and consists of the following:

    • The image subregion within the image subresource referred to by the video picture resource used as the reconstructed picture.

    • The DPB slot index to activate with the reconstructed picture.

    • The codec-specific reference information related to the reconstructed picture.

    Decode Output Picture Information

    Information related to the decode output picture used by a video decode operation is derived from pDecodeInfo->dstPictureResource and any codec-specific parameters provided in the pDecodeInfo->pNext chain, as defined by the codec-specific semantics, and consists of the following:

    • The image subregion within the image subresource referred to by the video picture resource used as the decode output picture.

    • The codec-specific picture information related to the decode output picture.

    Several limiting values are defined below that are referenced by the relevant valid usage statements of this command.

    • Let uint32_t activeReferencePictureCount be the size of the list of active reference pictures used by the video decode operation. Unless otherwise defined, activeReferencePictureCount is set to the value of pDecodeInfo->referenceSlotCount.

      • If the bound video session was created with an H.264 decode profile, then let activeReferencePictureCount be the value of pDecodeInfo->referenceSlotCount plus the number of elements of the pDecodeInfo->pReferenceSlots array that have a VkVideoDecodeH264DpbSlotInfoKHR structure included in their pNext chain with both pStdReferenceInfo->flags.top_field_flag and pStdReferenceInfo->flags.bottom_field_flag set.

        Note

        This means that the elements of pDecodeInfo->pReferenceSlots that include both a top and bottom field reference are counted as two separate active reference pictures, as described in the active reference picture list construction rules for H.264 decode operations.

    • Let VkOffset2D codedOffsetGranularity be the minimum alignment requirement for the coded offset of video picture resources. Unless otherwise defined, the value of the x and y members of codedOffsetGranularity are 0.

    • Let uint32_t dpbFrameUseCount[] be an array of size maxDpbSlots, where maxDpbSlots is the VkVideoSessionCreateInfoKHR::maxDpbSlots the bound video session was created with, with each element indicating the number of times a frame associated with the corresponding DPB slot index is referred to by the video coding operation. Let the initial value of each element of the array be 0.

      • If pDecodeInfo->pSetupReferenceSlot is not NULL, then dpbFrameUseCount[i] is incremented by one, where i equals pDecodeInfo->pSetupReferenceSlot->slotIndex. If the bound video session object was created with an H.264 decode profile, then dpbFrameUseCount[i] is decremented by one if either pStdReferenceInfo->flags.top_field_flag or pStdReferenceInfo->flags.bottom_field_flag is set in the VkVideoDecodeH264DpbSlotInfoKHR structure in the pDecodeInfo->pSetupReferenceSlot->pNext chain.

      • For each element of pDecodeInfo->pReferenceSlots, dpbFrameUseCount[i] is incremented by one, where i equals the slotIndex member of the corresponding element. If the bound video session object was created with an H.264 decode profile, then dpbFrameUseCount[i] is decremented by one if either pStdReferenceInfo->flags.top_field_flag or pStdReferenceInfo->flags.bottom_field_flag is set in the VkVideoDecodeH264DpbSlotInfoKHR structure in the pNext chain of the corresponding element of pDecodeInfo->pReferenceSlots.

    • Let uint32_t dpbTopFieldUseCount[] and uint32_t dpbBottomFieldUseCount[] be arrays of size maxDpbSlots, where maxDpbSlots is the VkVideoSessionCreateInfoKHR::maxDpbSlots the bound video session was created with, with each element indicating the number of times the top field or the bottom field, respectively, associated with the corresponding DPB slot index is referred to by the video coding operation. Let the initial value of each element of the arrays be 0.

      • If the bound video session object was created with an H.264 decode profile and pDecodeInfo->pSetupReferenceSlot is not NULL, then perform the following:

        • If pStdReferenceInfo->flags.top_field_flag is set in the VkVideoDecodeH264DpbSlotInfoKHR structure in the pDecodeInfo->pSetupReferenceSlot->pNext chain, then dpbTopFieldUseCount[i] is incremented by one, where i equals pDecodeInfo->pSetupReferenceSlot->slotIndex.

        • If pStdReferenceInfo->flags.bottom_field_flag is set in the VkVideoDecodeH264DpbSlotInfoKHR structure in the pDecodeInfo->pSetupReferenceSlot->pNext chain, then dpbBottomFieldUseCount[i] is incremented by one, where i equals pDecodeInfo->pSetupReferenceSlot->slotIndex.

      • If the bound video session object was created with an H.264 decode profile, then perform the following for each element of pDecodeInfo->pReferenceSlots:

        • If pStdReferenceInfo->flags.top_field_flag is set in the VkVideoDecodeH264DpbSlotInfoKHR structure in the pNext chain of the element, then dpbTopFieldUseCount[i] is incremented by one, where i equals the slotIndex member of the element.

        • If pStdReferenceInfo->flags.bottom_field_flag is set in the VkVideoDecodeH264DpbSlotInfoKHR structure in the pNext chain of the element, then dpbBottomFieldUseCount[i] is incremented by one, where i equals the slotIndex member of the element.

    Valid Usage

    • VUID-vkCmdDecodeVideoKHR-None-07011
      The bound video session must not be in uninitialized state at the time the command is executed on the device

    • VUID-vkCmdDecodeVideoKHR-opCount-07134
      For each active query, the active query index corresponding to the query type of that query plus opCount must be less than or equal to the last activatable query index corresponding to the query type of that query plus one

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07135
      pDecodeInfo->srcBuffer must be compatible with the video profile the bound video session was created with

    • VUID-vkCmdDecodeVideoKHR-commandBuffer-07136
      If commandBuffer is an unprotected command buffer and protectedNoFault is not supported, then pDecodeInfo->srcBuffer must not be a protected buffer

    • VUID-vkCmdDecodeVideoKHR-commandBuffer-07137
      If commandBuffer is a protected command buffer and protectedNoFault is not supported, then pDecodeInfo->srcBuffer must be a protected buffer

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07138
      pDecodeInfo->srcBufferOffset must be an integer multiple of VkVideoCapabilitiesKHR::minBitstreamBufferOffsetAlignment, as returned by vkGetPhysicalDeviceVideoCapabilitiesKHR for the video profile the bound video session was created with

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07139
      pDecodeInfo->srcBufferRange must be an integer multiple of VkVideoCapabilitiesKHR::minBitstreamBufferSizeAlignment, as returned by vkGetPhysicalDeviceVideoCapabilitiesKHR for the video profile the bound video session was created with

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07140
      If pDecodeInfo->pSetupReferenceSlot is not NULL and VkVideoDecodeCapabilitiesKHR::flags does not include VK_VIDEO_DECODE_CAPABILITY_DPB_AND_OUTPUT_COINCIDE_BIT_KHR, as returned by vkGetPhysicalDeviceVideoCapabilitiesKHR for the video profile the bound video session was created with, then the video picture resources specified by pDecodeInfo->dstPictureResource and pDecodeInfo->pSetupReferenceSlot->pPictureResource must not match

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07141
      If pDecodeInfo->pSetupReferenceSlot is not NULL and VkVideoDecodeCapabilitiesKHR::flags does not include VK_VIDEO_DECODE_CAPABILITY_DPB_AND_OUTPUT_DISTINCT_BIT_KHR, as returned by vkGetPhysicalDeviceVideoCapabilitiesKHR for the video profile the bound video session was created with, then the video picture resources specified by pDecodeInfo->dstPictureResource and pDecodeInfo->pSetupReferenceSlot->pPictureResource must match

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07142
      pDecodeInfo->dstPictureResource.imageViewBinding must be compatible with the video profile the bound video session was created with

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07143
      The format of pDecodeInfo->dstPictureResource.imageViewBinding must match the VkVideoSessionCreateInfoKHR::pictureFormat the bound video session was created with

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07144
      pDecodeInfo->dstPictureResource.codedOffset must be an integer multiple of codedOffsetGranularity

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07145
      pDecodeInfo->dstPictureResource.codedExtent must be between minCodedExtent and maxCodedExtent, inclusive, the bound video session was created with

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07146
      pDecodeInfo->dstPictureResource.imageViewBinding must have been created with VK_IMAGE_USAGE_VIDEO_DECODE_DST_BIT_KHR

    • VUID-vkCmdDecodeVideoKHR-commandBuffer-07147
      If commandBuffer is an unprotected command buffer and protectedNoFault is not supported, then pDecodeInfo->dstPictureResource.imageViewBinding must not have been created from a protected image

    • VUID-vkCmdDecodeVideoKHR-commandBuffer-07148
      If commandBuffer is a protected command buffer and protectedNoFault is not supported, then pDecodeInfo->dstPictureResource.imageViewBinding must have been created from a protected image

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07170
      If pDecodeInfo->pSetupReferenceSlot is not NULL, then pDecodeInfo->pSetupReferenceSlot->slotIndex must be less than the VkVideoSessionCreateInfoKHR::maxDpbSlots specified when the bound video session was created

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07173
      If pDecodeInfo->pSetupReferenceSlot is not NULL, then pDecodeInfo->pSetupReferenceSlot->pPictureResource->codedOffset must be an integer multiple of codedOffsetGranularity

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07149
      If pDecodeInfo->pSetupReferenceSlot is not NULL, then pDecodeInfo->pSetupReferenceSlot->pPictureResource must match one of the bound reference picture resource

    • VUID-vkCmdDecodeVideoKHR-activeReferencePictureCount-07150
      activeReferencePictureCount must be less than or equal to the VkVideoSessionCreateInfoKHR::maxActiveReferencePictures specified when the bound video session was created

    • VUID-vkCmdDecodeVideoKHR-slotIndex-07256
      The slotIndex member of each element of pDecodeInfo->pReferenceSlots must be less than the VkVideoSessionCreateInfoKHR::maxDpbSlots specified when the bound video session was created

    • VUID-vkCmdDecodeVideoKHR-codedOffset-07257
      The codedOffset member of the VkVideoPictureResourceInfoKHR structure pointed to by the pPictureResource member of each element of pDecodeInfo->pReferenceSlots must be an integer multiple of codedOffsetGranularity

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07151
      The pPictureResource member of each element of pDecodeInfo->pReferenceSlots must match one of the bound reference picture resource associated with the DPB slot index specified in the slotIndex member of that element

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07264
      Each video picture resource corresponding to the pPictureResource member specified in the elements of pDecodeInfo->pReferenceSlots must be unique within pDecodeInfo->pReferenceSlots

    • VUID-vkCmdDecodeVideoKHR-dpbFrameUseCount-07176
      All elements of dpbFrameUseCount must be less than or equal to 1

    • VUID-vkCmdDecodeVideoKHR-dpbTopFieldUseCount-07177
      All elements of dpbTopFieldUseCount must be less than or equal to 1

    • VUID-vkCmdDecodeVideoKHR-dpbBottomFieldUseCount-07178
      All elements of dpbBottomFieldUseCount must be less than or equal to 1

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07252
      If pDecodeInfo->pSetupReferenceSlot is NULL or pDecodeInfo->pSetupReferenceSlot->pPictureResource does not refer to the same image subresource as pDecodeInfo->dstPictureResource, then the image subresource referred to by pDecodeInfo->dstPictureResource must be in the VK_IMAGE_LAYOUT_VIDEO_DECODE_DST_KHR layout at the time the video decode operation is executed on the device

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07253
      If pDecodeInfo->pSetupReferenceSlot is not NULL and pDecodeInfo->pSetupReferenceSlot->pPictureResource refers to the same image subresource as pDecodeInfo->dstPictureResource, then the image subresource referred to by pDecodeInfo->dstPictureResource must be in the VK_IMAGE_LAYOUT_VIDEO_DECODE_DPB_KHR layout at the time the video decode operation is executed on the device

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07254
      If pDecodeInfo->pSetupReferenceSlot is not NULL, then the image subresource referred to by pDecodeInfo->pSetupReferenceSlot->pPictureResource must be in the VK_IMAGE_LAYOUT_VIDEO_DECODE_DPB_KHR layout at the time the video decode operation is executed on the device

    • VUID-vkCmdDecodeVideoKHR-pPictureResource-07255
      The image subresource referred to by the pPictureResource member of each element of pDecodeInfo->pReferenceSlots must be in the VK_IMAGE_LAYOUT_VIDEO_DECODE_DPB_KHR layout at the time the video decode operation is executed on the device

    • VUID-vkCmdDecodeVideoKHR-pNext-07152
      If the bound video session was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR, then the pNext chain of pDecodeInfo must include a VkVideoDecodeH264PictureInfoKHR structure

    • VUID-vkCmdDecodeVideoKHR-None-07258
      If the bound video session was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR but was not created with interlaced frame support, then the decode output picture must represent a frame

    • VUID-vkCmdDecodeVideoKHR-pSliceOffsets-07153
      If the bound video session was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR, then all elements of the pSliceOffsets member of the VkVideoDecodeH264PictureInfoKHR structure included in the pNext chain of pDecodeInfo must be less than pDecodeInfo->srcBufferRange

    • VUID-vkCmdDecodeVideoKHR-StdVideoH264SequenceParameterSet-07154
      If the bound video session was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR, then the bound video session parameters object must contain a StdVideoH264SequenceParameterSet entry with seq_parameter_set_id matching StdVideoDecodeH264PictureInfo::seq_parameter_set_id that is provided in the pStdPictureInfo member of the VkVideoDecodeH264PictureInfoKHR structure included in the pNext chain of pDecodeInfo

    • VUID-vkCmdDecodeVideoKHR-StdVideoH264PictureParameterSet-07155
      If the bound video session was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR, then the bound video session parameters object must contain a StdVideoH264PictureParameterSet entry with seq_parameter_set_id and pic_parameter_set_id matching StdVideoDecodeH264PictureInfo::seq_parameter_set_id and StdVideoDecodeH264PictureInfo::pic_parameter_set_id, respectively, that are provided in the pStdPictureInfo member of the VkVideoDecodeH264PictureInfoKHR structure included in the pNext chain of pDecodeInfo

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07156
      If the bound video session was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR and pDecodeInfo->pSetupReferenceSlot is not NULL, then the pNext chain of pDecodeInfo->pSetupReferenceSlot must include a VkVideoDecodeH264DpbSlotInfoKHR structure

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07259
      If the bound video session was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR but was not created with interlaced frame support, and pDecodeInfo->pSetupReferenceSlot is not NULL, then the reconstructed picture must represent a frame

    • VUID-vkCmdDecodeVideoKHR-pNext-07157
      If the bound video session was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR, then the pNext chain of each element of pDecodeInfo->pReferenceSlots must include a VkVideoDecodeH264DpbSlotInfoKHR structure

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07260
      If the bound video session was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR but was not created with interlaced frame support, then each active reference picture corresponding to the elements of pDecodeInfo->pReferenceSlots must represent a frame

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07261
      If the bound video session was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR, pDecodeInfo->pSetupReferenceSlot is not NULL, and the decode output picture represents a frame, then the reconstructed picture must also represent a frame

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07262
      If the bound video session was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR, pDecodeInfo->pSetupReferenceSlot is not NULL, and the decode output picture represents a top field, then the reconstructed picture must also represent a top field

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07263
      If the bound video session was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR, pDecodeInfo->pSetupReferenceSlot is not NULL, and the decode output picture represents a bottom field, then the reconstructed picture must also represent a bottom field

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07266
      If the bound video session was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR and an active reference picture corresponding to any element of pDecodeInfo->pReferenceSlots represents a frame, then the DPB slot index of the bound video session specified by the slotIndex member of that element must be currently associated with a frame picture matching the video picture resource specified by the pPictureResource member of the same element at the time the command is executed on the device

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07267
      If the bound video session was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR and an active reference picture corresponding to any element of pDecodeInfo->pReferenceSlots represents a top field, then the DPB slot index of the bound video session specified by the slotIndex member of that element must be currently associated with a top field picture matching the video picture resource specified by the pPictureResource member of the same element at the time the command is executed on the device

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07268
      If the bound video session was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR and an active reference picture corresponding to any element of pDecodeInfo->pReferenceSlots represents a bottom field, then the DPB slot index of the bound video session specified by the slotIndex member of that element must be currently associated with a bottom field picture matching the video picture resource specified by the pPictureResource member of the same element at the time the command is executed on the device

    • VUID-vkCmdDecodeVideoKHR-pNext-07158
      If the bound video session was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR, then the pNext chain of pDecodeInfo must include a VkVideoDecodeH265PictureInfoKHR structure

    • VUID-vkCmdDecodeVideoKHR-pSliceSegmentOffsets-07159
      If the bound video session was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR, then all elements of the pSliceSegmentOffsets member of the VkVideoDecodeH265PictureInfoKHR structure included in the pNext chain of pDecodeInfo must be less than pDecodeInfo->srcBufferRange

    • VUID-vkCmdDecodeVideoKHR-StdVideoH265VideoParameterSet-07160
      If the bound video session was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR, then the bound video session parameters object must contain a StdVideoH265VideoParameterSet entry with vps_video_parameter_set_id matching StdVideoDecodeH265PictureInfo::sps_video_parameter_set_id that is provided in the pStdPictureInfo member of the VkVideoDecodeH265PictureInfoKHR structure included in the pNext chain of pDecodeInfo

    • VUID-vkCmdDecodeVideoKHR-StdVideoH265SequenceParameterSet-07161
      If the bound video session was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR, then the bound video session parameters object must contain a StdVideoH265SequenceParameterSet entry with sps_video_parameter_set_id and sps_seq_parameter_set_id matching StdVideoDecodeH265PictureInfo::sps_video_parameter_set_id and StdVideoDecodeH265PictureInfo::pps_seq_parameter_set_id, respectively, that are provided in the pStdPictureInfo member of the VkVideoDecodeH265PictureInfoKHR structure included in the pNext chain of pDecodeInfo

    • VUID-vkCmdDecodeVideoKHR-StdVideoH265PictureParameterSet-07162
      If the bound video session was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR, then the bound video session parameters object must contain a StdVideoH265PictureParameterSet entry with sps_video_parameter_set_id, pps_seq_parameter_set_id, and pps_pic_parameter_set_id matching StdVideoDecodeH265PictureInfo::sps_video_parameter_set_id, StdVideoDecodeH265PictureInfo::pps_seq_parameter_set_id, and StdVideoDecodeH265PictureInfo::pps_pic_parameter_set_id, respectively, that are provided in the pStdPictureInfo member of the VkVideoDecodeH265PictureInfoKHR structure included in the pNext chain of pDecodeInfo

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-07163
      If the bound video session was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR and pDecodeInfo->pSetupReferenceSlot is not NULL, then the pNext chain of pDecodeInfo->pSetupReferenceSlot must include a VkVideoDecodeH265DpbSlotInfoKHR structure

    • VUID-vkCmdDecodeVideoKHR-pNext-07164
      If the bound video session was created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR, then the pNext chain of each element of pDecodeInfo->pReferenceSlots must include a VkVideoDecodeH265DpbSlotInfoKHR structure

    Valid Usage (Implicit)

    • VUID-vkCmdDecodeVideoKHR-commandBuffer-parameter
      commandBuffer must be a valid VkCommandBuffer handle

    • VUID-vkCmdDecodeVideoKHR-pDecodeInfo-parameter
      pDecodeInfo must be a valid pointer to a valid VkVideoDecodeInfoKHR structure

    • VUID-vkCmdDecodeVideoKHR-commandBuffer-recording
      commandBuffer must be in the recording state

    • VUID-vkCmdDecodeVideoKHR-commandBuffer-cmdpool
      The VkCommandPool that commandBuffer was allocated from must support decode operations

    • VUID-vkCmdDecodeVideoKHR-renderpass
      This command must only be called outside of a render pass instance

    • VUID-vkCmdDecodeVideoKHR-videocoding
      This command must only be called inside of a video coding scope

    • VUID-vkCmdDecodeVideoKHR-bufferlevel
      commandBuffer must be a primary VkCommandBuffer

    Host Synchronization

    • Host access to commandBuffer must be externally synchronized

    • Host access to the VkCommandPool that commandBuffer was allocated from must be externally synchronized

    Command Properties
    Command Buffer Levels Render Pass Scope Video Coding Scope Supported Queue Types Command Type

    Primary

    Outside

    Inside

    Decode

    Action

    The VkVideoDecodeInfoKHR structure is defined as:

    // Provided by VK_KHR_video_decode_queue
typedef struct VkVideoDecodeInfoKHR {
    VkStructureType                       sType;
    const void*                           pNext;
    VkVideoDecodeFlagsKHR                 flags;
    VkBuffer                              srcBuffer;
    VkDeviceSize                          srcBufferOffset;
    VkDeviceSize                          srcBufferRange;
    VkVideoPictureResourceInfoKHR         dstPictureResource;
    const VkVideoReferenceSlotInfoKHR*    pSetupReferenceSlot;
    uint32_t                              referenceSlotCount;
    const VkVideoReferenceSlotInfoKHR*    pReferenceSlots;
} VkVideoDecodeInfoKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • flags is reserved for future use.

    • srcBuffer is the source video bitstream buffer to read the encoded bitstream from.

    • srcBufferOffset is the starting offset in bytes from the start of srcBuffer to read the encoded bitstream from.

    • srcBufferRange is the size in bytes of the encoded bitstream to decode from srcBuffer, starting from srcBufferOffset.

    • dstPictureResource is the video picture resource to use as the decode output picture.

    • pSetupReferenceSlot is NULL or a pointer to a VkVideoReferenceSlotInfoKHR structure describing the DPB slot to activate and the video picture resource to use as the reconstructed picture to activate the DPB slot with.

    • referenceSlotCount is the number of elements in the pReferenceSlots array.

    • pReferenceSlots is NULL or a pointer to an array of VkVideoReferenceSlotInfoKHR structures describing the DPB slots and corresponding reference picture resources to use in this video decode operation (the set of active reference pictures).

    Valid Usage

    • VUID-VkVideoDecodeInfoKHR-srcBuffer-07165
      srcBuffer must have been created with VK_BUFFER_USAGE_VIDEO_DECODE_SRC_BIT_KHR set

    • VUID-VkVideoDecodeInfoKHR-srcBufferOffset-07166
      srcBufferOffset must be less than the size of srcBuffer

    • VUID-VkVideoDecodeInfoKHR-srcBufferRange-07167
      srcBufferRange must be less than or equal to the size of srcBuffer minus srcBufferOffset

    • VUID-VkVideoDecodeInfoKHR-pSetupReferenceSlot-07168
      If pSetupReferenceSlot is not NULL, then its slotIndex member must not be negative

    • VUID-VkVideoDecodeInfoKHR-pSetupReferenceSlot-07169
      If pSetupReferenceSlot is not NULL, then its pPictureResource must not be NULL

    • VUID-VkVideoDecodeInfoKHR-slotIndex-07171
      The slotIndex member of each element of pReferenceSlots must not be negative

    • VUID-VkVideoDecodeInfoKHR-pPictureResource-07172
      The pPictureResource member of each element of pReferenceSlots must not be NULL

    Valid Usage (Implicit)

    • VUID-VkVideoDecodeInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_DECODE_INFO_KHR

    • VUID-VkVideoDecodeInfoKHR-pNext-pNext
      Each pNext member of any structure (including this one) in the pNext chain must be either NULL or a pointer to a valid instance of VkVideoDecodeH264PictureInfoKHR or VkVideoDecodeH265PictureInfoKHR

    • VUID-VkVideoDecodeInfoKHR-sType-unique
      The sType value of each struct in the pNext chain must be unique

    • VUID-VkVideoDecodeInfoKHR-flags-zerobitmask
      flags must be 0

    • VUID-VkVideoDecodeInfoKHR-srcBuffer-parameter
      srcBuffer must be a valid VkBuffer handle

    • VUID-VkVideoDecodeInfoKHR-dstPictureResource-parameter
      dstPictureResource must be a valid VkVideoPictureResourceInfoKHR structure

    • VUID-VkVideoDecodeInfoKHR-pSetupReferenceSlot-parameter
      If pSetupReferenceSlot is not NULL, pSetupReferenceSlot must be a valid pointer to a valid VkVideoReferenceSlotInfoKHR structure

    • VUID-VkVideoDecodeInfoKHR-pReferenceSlots-parameter
      If referenceSlotCount is not 0, pReferenceSlots must be a valid pointer to an array of referenceSlotCount valid VkVideoReferenceSlotInfoKHR structures

    // Provided by VK_KHR_video_decode_queue
typedef VkFlags VkVideoDecodeFlagsKHR;

    VkVideoDecodeFlagsKHR is a bitmask type for setting a mask, but is currently reserved for future use.

    36.11. H.264 Decode Operations

    Video decode operations using an H.264 decode profile can be used to decode elementary video stream sequences compliant to the ITU-T H.264 Specification.

    Note

    Refer to the Preamble for information on how the Khronos Intellectual Property Rights Policy relates to normative references to external materials not created by Khronos.

    This process is performed according to the video decode operation steps with the codec-specific semantics defined in section 8 of the ITU-T H.264 Specification as follows:

    If the parameters and the bitstream adhere to the syntactic and semantic requirements defined in the corresponding sections of the ITU-T H.264 Specification, as described above, and the DPB slots associated with the active reference pictures all refer to valid picture references, then the video decode operation will complete successfully. Otherwise, the video decode operation may complete unsuccessfully.

    36.11.1. H.264 Decode Bitstream Data Access

    If the target decode output picture is a frame, then the video bitstream buffer range should contain a VCL NAL unit comprised of the slice headers and data of a picture representing an entire frame, as defined in sections 7.3.3 and 7.3.4, and this data is interpreted as defined in sections 7.4.3 and 7.4.4 of the ITU-T H.264 Specification, respectively.

    If the target decode output picture is a field, then the video bitstream buffer range should contain a VCL NAL unit comprised of the slice headers and data of a picture representing a field, as defined in sections 7.3.3 and 7.3.4, and this data is interpreted as defined in sections 7.4.3 and 7.4.4 of the ITU-T H.264 Specification, respectively.

    The offsets provided in VkVideoDecodeH264PictureInfoKHR::pSliceOffsets should specify the starting offsets corresponding to each slice header within the video bitstream buffer range.

    36.11.2. H.264 Decode Picture Data Access

    The effective imageOffset and imageExtent corresponding to a decode output picture, reference picture, or reconstructed picture used in video decode operations with an H.264 decode profile are defined as follows:

    • imageOffset is (codedOffset.x,codedOffset.y) and imageExtent is (codedExtent.width, codedExtent.height), if the picture represents a frame.

    • imageOffset is (codedOffset.x,codedOffset.y) and imageExtent is (codedExtent.width, codedExtent.height), if the picture represents a field and the picture layout of the used H.264 decode profile is VK_VIDEO_DECODE_H264_PICTURE_LAYOUT_INTERLACED_INTERLEAVED_LINES_BIT_KHR.

    • imageOffset is (codedOffset.x,codedOffset.y) and imageExtent is (codedExtent.width, codedExtent.height / 2), if the picture represents a field and the picture layout of the used H.264 decode profile is VK_VIDEO_DECODE_H264_PICTURE_LAYOUT_INTERLACED_SEPARATE_PLANES_BIT_KHR.

    Where codedOffset and codedExtent are the members of the VkVideoPictureResourceInfoKHR structure corresponding to the picture.

    However, accesses to image data within a video picture resource happen at the granularity indicated by VkVideoCapabilitiesKHR::pictureAccessGranularity, as returned by vkGetPhysicalDeviceVideoCapabilitiesKHR for the used video profile. This means that the complete image subregion accessed by video coding operations using an H.264 decode profile for the video picture resource is defined as the set of texels within the coordinate range:

    ([startX,endX),[startY,endY))

    Where:

    • startX equals imageOffset.x rounded down to the nearest integer multiple of pictureAccessGranularity.width;

    • endX equals imageOffset.x + imageExtent.width rounded up to the nearest integer multiple of pictureAccessGranularity.width and clamped to the width of the image subresource referred to by the corresponding VkVideoPictureResourceInfoKHR structure;

    • startY equals imageOffset.y rounded down to the nearest integer multiple of pictureAccessGranularity.height;

    • endY equals imageOffset.y + imageExtent.height rounded up to the nearest integer multiple of pictureAccessGranularity.height and clamped to the height of the image subresource referred to by the corresponding VkVideoPictureResourceInfoKHR structure.

    In case of video decode operations using an H.264 decode profile, any access to a picture at the coordinates (x,y), as defined by the ITU-T H.264 Specification, is an access to the image subresource referred to by the corresponding VkVideoPictureResourceInfoKHR structure at the texel coordinates specified below:

    • (x,y), if the accessed picture represents a frame.

    • (x,y × 2), if the accessed picture represents a top field and the picture layout of the used H.264 decode profile is VK_VIDEO_DECODE_H264_PICTURE_LAYOUT_INTERLACED_INTERLEAVED_LINES_BIT_KHR.

    • (x,y × 2 + 1), if the accessed picture represents a bottom field and the picture layout of the used H.264 decode profile is VK_VIDEO_DECODE_H264_PICTURE_LAYOUT_INTERLACED_INTERLEAVED_LINES_BIT_KHR.

    • (x,y), if the accessed picture represents a top field and the picture layout of the used H.264 decode profile is VK_VIDEO_DECODE_H264_PICTURE_LAYOUT_INTERLACED_SEPARATE_PLANES_BIT_KHR.

    • (codedOffset.x + x,codedOffset.y + y), if the accessed picture represents a bottom field and the picture layout of the used H.264 decode profile is VK_VIDEO_DECODE_H264_PICTURE_LAYOUT_INTERLACED_SEPARATE_PLANES_BIT_KHR.

    Where codedOffset is the member of the corresponding VkVideoPictureResourceInfoKHR structure.

    36.11.3. H.264 Decode Profile

    A video profile supporting H.264 video decode operations is specified by setting VkVideoProfileInfoKHR::videoCodecOperation to VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR and adding a VkVideoDecodeH264ProfileInfoKHR structure to the VkVideoProfileInfoKHR::pNext chain.

    The VkVideoDecodeH264ProfileInfoKHR structure is defined as:

    // Provided by VK_KHR_video_decode_h264
typedef struct VkVideoDecodeH264ProfileInfoKHR {
    VkStructureType                              sType;
    const void*                                  pNext;
    StdVideoH264ProfileIdc                       stdProfileIdc;
    VkVideoDecodeH264PictureLayoutFlagBitsKHR    pictureLayout;
} VkVideoDecodeH264ProfileInfoKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • stdProfileIdc is a StdVideoH264ProfileIdc value specifying the H.264 codec profile IDC, as defined in section A.2 of the ITU-T H.264 Specification.

    • pictureLayout is a VkVideoDecodeH264PictureLayoutFlagBitsKHR value specifying the picture layout used by the H.264 video sequence to be decoded.

    Valid Usage (Implicit)

    • VUID-VkVideoDecodeH264ProfileInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_DECODE_H264_PROFILE_INFO_KHR

    • VUID-VkVideoDecodeH264ProfileInfoKHR-pictureLayout-parameter
      If pictureLayout is not 0, pictureLayout must be a valid VkVideoDecodeH264PictureLayoutFlagBitsKHR value

    The H.264 video decode picture layout flags are defined as follows:

    // Provided by VK_KHR_video_decode_h264
typedef enum VkVideoDecodeH264PictureLayoutFlagBitsKHR {
    VK_VIDEO_DECODE_H264_PICTURE_LAYOUT_PROGRESSIVE_KHR = 0,
    VK_VIDEO_DECODE_H264_PICTURE_LAYOUT_INTERLACED_INTERLEAVED_LINES_BIT_KHR = 0x00000001,
    VK_VIDEO_DECODE_H264_PICTURE_LAYOUT_INTERLACED_SEPARATE_PLANES_BIT_KHR = 0x00000002,
} VkVideoDecodeH264PictureLayoutFlagBitsKHR;

    • VK_VIDEO_DECODE_H264_PICTURE_LAYOUT_PROGRESSIVE_KHR specifies support for progressive content. This flag has the value 0.

    • VK_VIDEO_DECODE_H264_PICTURE_LAYOUT_INTERLACED_INTERLEAVED_LINES_BIT_KHR specifies support for or use of a picture layout for interlaced content where all lines belonging to the top field are decoded to the even-numbered lines within the picture resource, and all lines belonging to the bottom field are decoded to the odd-numbered lines within the picture resource.

    • VK_VIDEO_DECODE_H264_PICTURE_LAYOUT_INTERLACED_SEPARATE_PLANES_BIT_KHR specifies support for or use of a picture layout for interlaced content where all lines belonging to a field are grouped together in a single image subregion, and the two fields comprising the frame can be stored in separate image subregions of the same image subresource or in separate image subresources.

    // Provided by VK_KHR_video_decode_h264
typedef VkFlags VkVideoDecodeH264PictureLayoutFlagsKHR;

    VkVideoDecodeH264PictureLayoutFlagsKHR is a bitmask type for setting a mask of zero or more VkVideoDecodeH264PictureLayoutFlagBitsKHR.

    36.11.4. H.264 Decode Capabilities

    When calling vkGetPhysicalDeviceVideoCapabilitiesKHR to query the capabilities for an H.264 decode profile, the VkVideoCapabilitiesKHR::pNext chain must include a VkVideoDecodeH264CapabilitiesKHR structure that will be filled with the profile-specific capabilities.

    The VkVideoDecodeH264CapabilitiesKHR structure is defined as:

    // Provided by VK_KHR_video_decode_h264
typedef struct VkVideoDecodeH264CapabilitiesKHR {
    VkStructureType         sType;
    void*                   pNext;
    StdVideoH264LevelIdc    maxLevelIdc;
    VkOffset2D              fieldOffsetGranularity;
} VkVideoDecodeH264CapabilitiesKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • maxLevelIdc is a StdVideoH264LevelIdc value specifying the maximum H.264 level supported by the profile, as defined in section A.3 of the ITU-T H.264 Specification.

    • fieldOffsetGranularity is the minimum alignment for VkVideoPictureResourceInfoKHR::codedOffset specified for a video picture resource when using the picture layout VK_VIDEO_DECODE_H264_PICTURE_LAYOUT_INTERLACED_SEPARATE_PLANES_BIT_KHR.

    Valid Usage (Implicit)

    • VUID-VkVideoDecodeH264CapabilitiesKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_DECODE_H264_CAPABILITIES_KHR

    36.11.5. H.264 Decode Parameter Sets

    Video session parameters objects created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR can contain the following types of parameters:

    H.264 Sequence Parameter Sets (SPS)

    Represented by StdVideoH264SequenceParameterSet structures and interpreted as follows:

    • reserved1 and reserved2 are used only for padding purposes and are otherwise ignored;

    • seq_parameter_set_id is used as the key of the SPS entry;

    • if flags.seq_scaling_matrix_present_flag is set, then the StdVideoH264ScalingLists structure pointed to by pScalingLists is interpreted as follows:

      • scaling_list_present_mask is a bitmask where bit index i corresponds to seq_scaling_list_present_flag[i] as defined in section 7.4.2.1 of the ITU-T H.264 Specification;

      • use_default_scaling_matrix_mask is a bitmask where bit index i corresponds to UseDefaultScalingMatrix4x4Flag[i], when i < 6, or corresponds to UseDefaultScalingMatrix8x8Flag[i-6], otherwise, as defined in section 7.3.2.1 of the ITU-T H.264 Specification;

      • ScalingList4x4 and ScalingList8x8 correspond to the identically named syntax elements defined in section 7.3.2.1 of the ITU-T H.264 Specification;

    • if flags.vui_parameters_present_flag is set, then pSequenceParameterSetVui points to a StdVideoH264SequenceParameterSetVui structure that is interpreted as follows:

      • reserved1 is used only for padding purposes and is otherwise ignored;

      • if flags.nal_hrd_parameters_present_flag or flags.vcl_hrd_parameters_present_flag is set, then the StdVideoH264HrdParameters structure pointed to by pHrdParameters is interpreted as follows:

        • reserved1 is used only for padding purposes and is otherwise ignored;

        • all other members of StdVideoH264HrdParameters are interpreted as defined in section E.2.2 of the ITU-T H.264 Specification;

      • all other members of StdVideoH264SequenceParameterSetVui are interpreted as defined in section E.2.1 of the ITU-T H.264 Specification;

    • all other members of StdVideoH264SequenceParameterSet are interpreted as defined in section 7.4.2.1 of the ITU-T H.264 Specification.

    H.264 Picture Parameter Sets (PPS)

    Represented by StdVideoH264PictureParameterSet structures and interpreted as follows:

    • the pair constructed from seq_parameter_set_id and pic_parameter_set_id is used as the key of the PPS entry;

    • if flags.pic_scaling_matrix_present_flag is set, then the StdVideoH264ScalingLists structure pointed to by pScalingLists is interpreted as follows:

      • scaling_list_present_mask is a bitmask where bit index i corresponds to pic_scaling_list_present_flag[i] as defined in section 7.4.2.2 of the ITU-T H.264 Specification;

      • use_default_scaling_matrix_mask is a bitmask where bit index i corresponds to UseDefaultScalingMatrix4x4Flag[i], when i < 6, or corresponds to UseDefaultScalingMatrix8x8Flag[i-6], otherwise, as defined in section 7.3.2.2 of the ITU-T H.264 Specification;

      • ScalingList4x4 and ScalingList8x8 correspond to the identically named syntax elements defined in section 7.3.2.2 of the ITU-T H.264 Specification;

    • all other members of StdVideoH264PictureParameterSet are interpreted as defined in section 7.4.2.2 of the ITU-T H.264 Specification.

    When a video session parameters object is created with the codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR, the VkVideoSessionParametersCreateInfoKHR::pNext chain must include a VkVideoDecodeH264SessionParametersCreateInfoKHR structure specifying the capacity and initial contents of the object.

    The VkVideoDecodeH264SessionParametersCreateInfoKHR structure is defined as:

    // Provided by VK_KHR_video_decode_h264
typedef struct VkVideoDecodeH264SessionParametersCreateInfoKHR {
    VkStructureType                                        sType;
    const void*                                            pNext;
    uint32_t                                               maxStdSPSCount;
    uint32_t                                               maxStdPPSCount;
    const VkVideoDecodeH264SessionParametersAddInfoKHR*    pParametersAddInfo;
} VkVideoDecodeH264SessionParametersCreateInfoKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • maxStdSPSCount is the maximum number of H.264 SPS entries the created VkVideoSessionParametersKHR can contain.

    • maxStdPPSCount is the maximum number of H.264 PPS entries the created VkVideoSessionParametersKHR can contain.

    • pParametersAddInfo is NULL or a pointer to a VkVideoDecodeH264SessionParametersAddInfoKHR structure specifying H.264 parameters to add upon object creation.

    Valid Usage (Implicit)

    • VUID-VkVideoDecodeH264SessionParametersCreateInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_DECODE_H264_SESSION_PARAMETERS_CREATE_INFO_KHR

    • VUID-VkVideoDecodeH264SessionParametersCreateInfoKHR-pParametersAddInfo-parameter
      If pParametersAddInfo is not NULL, pParametersAddInfo must be a valid pointer to a valid VkVideoDecodeH264SessionParametersAddInfoKHR structure

    The VkVideoDecodeH264SessionParametersAddInfoKHR structure is defined as:

    // Provided by VK_KHR_video_decode_h264
typedef struct VkVideoDecodeH264SessionParametersAddInfoKHR {
    VkStructureType                            sType;
    const void*                                pNext;
    uint32_t                                   stdSPSCount;
    const StdVideoH264SequenceParameterSet*    pStdSPSs;
    uint32_t                                   stdPPSCount;
    const StdVideoH264PictureParameterSet*     pStdPPSs;
} VkVideoDecodeH264SessionParametersAddInfoKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • stdSPSCount is the number of elements in the pStdSPSs array.

    • pStdSPSs is a pointer to an array of StdVideoH264SequenceParameterSet structures describing the H.264 SPS entries to add.

    • stdPPSCount is the number of elements in the pStdPPSs array.

    • pStdPPSs is a pointer to an array of StdVideoH264PictureParameterSet structures describing the H.264 PPS entries to add.

    This structure can be specified in the following places:

    Valid Usage

    • VUID-VkVideoDecodeH264SessionParametersAddInfoKHR-None-04825
      The seq_parameter_set_id member of each StdVideoH264SequenceParameterSet structure specified in the elements of pStdSPSs must be unique within pStdSPSs

    • VUID-VkVideoDecodeH264SessionParametersAddInfoKHR-None-04826
      The pair constructed from the seq_parameter_set_id and pic_parameter_set_id members of each StdVideoH264PictureParameterSet structure specified in the elements of pStdPPSs must be unique within pStdPPSs

    Valid Usage (Implicit)

    • VUID-VkVideoDecodeH264SessionParametersAddInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_DECODE_H264_SESSION_PARAMETERS_ADD_INFO_KHR

    • VUID-VkVideoDecodeH264SessionParametersAddInfoKHR-pStdSPSs-parameter
      If stdSPSCount is not 0, pStdSPSs must be a valid pointer to an array of stdSPSCount StdVideoH264SequenceParameterSet values

    • VUID-VkVideoDecodeH264SessionParametersAddInfoKHR-pStdPPSs-parameter
      If stdPPSCount is not 0, pStdPPSs must be a valid pointer to an array of stdPPSCount StdVideoH264PictureParameterSet values

    36.11.6. H.264 Decoding Parameters

    The VkVideoDecodeH264PictureInfoKHR structure is defined as:

    // Provided by VK_KHR_video_decode_h264
typedef struct VkVideoDecodeH264PictureInfoKHR {
    VkStructureType                         sType;
    const void*                             pNext;
    const StdVideoDecodeH264PictureInfo*    pStdPictureInfo;
    uint32_t                                sliceCount;
    const uint32_t*                         pSliceOffsets;
} VkVideoDecodeH264PictureInfoKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • pStdPictureInfo is a pointer to a StdVideoDecodeH264PictureInfo structure specifying H.264 picture information.

    • sliceCount is the number of elements in pSliceOffsets.

    • pSliceOffsets is a pointer to an array of sliceCount offsets specifying the start offset of the slices of the picture within the video bitstream buffer range specified in VkVideoDecodeInfoKHR.

    This structure is specified in the pNext chain of the VkVideoDecodeInfoKHR structure passed to vkCmdDecodeVideoKHR to specify the codec-specific picture information for an H.264 decode operation.

    Decode Output Picture Information

    When this structure is specified in the pNext chain of the VkVideoDecodeInfoKHR structure passed to vkCmdDecodeVideoKHR, the information related to the decode output picture is defined as follows:

    • If pStdPictureInfo->flags.field_pic_flag is not set, then the picture represents a frame.

    • If pStdPictureInfo->flags.field_pic_flag is set, then the picture represents a field. Specifically:

      • If pStdPictureInfo->flags.bottom_field_flag is not set, then the picture represents the top field of the frame.

      • If pStdPictureInfo->flags.bottom_field_flag is set, then the picture represents the bottom field of the frame.

    • The image subregion used is determined according to the H.264 Decode Picture Data Access section.

    • The decode output picture is associated with the H.264 picture information provided in pStdPictureInfo.

    Std Picture Information

    The members of the StdVideoDecodeH264PictureInfo structure pointed to by pStdPictureInfo are interpreted as follows:

    • reserved1 and reserved2 are used only for padding purposes and are otherwise ignored;

    • flags.is_intra as defined in section 3.73 of the ITU-T H.264 Specification;

    • flags.is_reference as defined in section 3.136 of the ITU-T H.264 Specification;

    • flags.complementary_field_pair as defined in section 3.35 of the ITU-T H.264 Specification;

    • seq_parameter_set_id and pic_parameter_set_id are used to identify the active parameter sets, as described below;

    • all other members are interpreted as defined in section 7.4.3 of the ITU-T H.264 Specification.

    Active Parameter Sets

    The members of the StdVideoDecodeH264PictureInfo structure pointed to by pStdPictureInfo are used to select the active parameter sets to use from the bound video session parameters object, as follows:

    • The active SPS is the SPS identified by the key specified in StdVideoDecodeH264PictureInfo::seq_parameter_set_id.

    • The active PPS is the PPS identified by the key specified by the pair constructed from StdVideoDecodeH264PictureInfo::seq_parameter_set_id and StdVideoDecodeH264PictureInfo::pic_parameter_set_id.

    Valid Usage (Implicit)

    • VUID-VkVideoDecodeH264PictureInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_DECODE_H264_PICTURE_INFO_KHR

    • VUID-VkVideoDecodeH264PictureInfoKHR-pStdPictureInfo-parameter
      pStdPictureInfo must be a valid pointer to a valid StdVideoDecodeH264PictureInfo value

    • VUID-VkVideoDecodeH264PictureInfoKHR-pSliceOffsets-parameter
      pSliceOffsets must be a valid pointer to an array of sliceCount uint32_t values

    • VUID-VkVideoDecodeH264PictureInfoKHR-sliceCount-arraylength
      sliceCount must be greater than 0

    The VkVideoDecodeH264DpbSlotInfoKHR structure is defined as:

    // Provided by VK_KHR_video_decode_h264
typedef struct VkVideoDecodeH264DpbSlotInfoKHR {
    VkStructureType                           sType;
    const void*                               pNext;
    const StdVideoDecodeH264ReferenceInfo*    pStdReferenceInfo;
} VkVideoDecodeH264DpbSlotInfoKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • pStdReferenceInfo is a pointer to a StdVideoDecodeH264ReferenceInfo structure specifying H.264 reference information.

    This structure is specified in the pNext chain of VkVideoDecodeInfoKHR::pSetupReferenceSlot, if not NULL, and the pNext chain of the elements of VkVideoDecodeInfoKHR::pReferenceSlots to specify the codec-specific reference picture information for an H.264 decode operation.

    Active Reference Picture Information

    When this structure is specified in the pNext chain of the elements of VkVideoDecodeInfoKHR::pReferenceSlots, one or two elements are added to the list of active reference pictures used by the video decode operation for each element of VkVideoDecodeInfoKHR::pReferenceSlots as follows:

    • If neither pStdReferenceInfo->flags.top_field_flag nor pStdReferenceInfo->flags.bottom_field_flag is set, then the picture is added as a frame reference to the list of active reference pictures.

    • If pStdReferenceInfo->flags.top_field_flag is set, then the picture is added as a top field reference to the list of active reference pictures.

    • If pStdReferenceInfo->flags.bottom_field_flag is set, then the picture is added as a bottom field reference to the list of active reference pictures.

    • For each added reference picture, the corresponding image subregion used is determined according to the H.264 Decode Picture Data Access section.

    • Each added reference picture is associated with the DPB slot index specified in the slotIndex member of the corresponding element of VkVideoDecodeInfoKHR::pReferenceSlots.

    • Each added reference picture is associated with the H.264 reference information provided in pStdReferenceInfo.

    Note

    When both the top and bottom field of an interlaced frame currently associated with a DPB slot is intended to be used as an active reference picture and both fields are stored in the same image subregion (which is the case when using VK_VIDEO_DECODE_H264_PICTURE_LAYOUT_INTERLACED_INTERLEAVED_LINES_BIT_KHR which stores the two fields at even and odd scanlines of the same image subregion), both references have to be provided through a single VkVideoReferenceSlotInfoKHR structure that has both flags.top_field_flag and flags.bottom_field_flag set in the StdVideoDecodeH264ReferenceInfo structure pointed to by the pStdReferenceInfo member of the VkVideoDecodeH264DpbSlotInfoKHR structure included in the corresponding VkVideoReferenceSlotInfoKHR structure’s pNext chain. However, this approach can only be used when both fields are stored in the same image subregion. If that is not the case (e.g. when using VK_VIDEO_DECODE_H264_PICTURE_LAYOUT_INTERLACED_SEPARATE_PLANES_BIT_KHR which requires separate codedOffset values for the two fields and also allows storing the two fields of a frame in separate image layers or entirely separate images), then a separate VkVideoReferenceSlotInfoKHR structure needs to be provided for referencing the two fields, each only setting one of flags.top_field_flag or flags.bottom_field_flag, and providing the appropriate video picture resource information in VkVideoReferenceSlotInfoKHR::pPictureResource.
    Reconstructed Picture Information

    When this structure is specified in the pNext chain of VkVideoDecodeInfoKHR::pSetupReferenceSlot, the information related to the reconstructed picture is defined as follows:

    • If neither pStdReferenceInfo->flags.top_field_flag nor pStdReferenceInfo->flags.bottom_field_flag is set, then the picture represents a frame.

    • If pStdReferenceInfo->flags.top_field_flag is set, then the picture represents a field, specifically, the top field of the frame.

    • If pStdReferenceInfo->flags.bottom_field_flag is set, then the picture represents a field, specifically, the bottom field of the frame.

    • The image subregion used is determined according to the H.264 Decode Picture Data Access section.

    • The reconstructed picture is used to activate the DPB slot with the index specified in VkVideoDecodeInfoKHR::pSetupReferenceSlot->slotIndex.

    • The reconstructed picture is associated with the H.264 reference information provided in pStdReferenceInfo.

    Std Reference Information

    The members of the StdVideoDecodeH264ReferenceInfo structure pointed to by pStdReferenceInfo are interpreted as follows:

    • flags.top_field_flag is used to indicate whether the reference is used as top field reference;

    • flags.bottom_field_flag is used to indicate whether the reference is used as bottom field reference;

    • flags.used_for_long_term_reference is used to indicate whether the picture is marked as “used for long-term reference” as defined in section 8.2.5.1 of the ITU-T H.264 Specification;

    • flags.is_non_existing is used to indicate whether the picture is marked as “non-existing” as defined in section 8.2.5.2 of the ITU-T H.264 Specification;

    • all other members are interpreted as defined in section 8.2 of the ITU-T H.264 Specification.

    Valid Usage (Implicit)

    • VUID-VkVideoDecodeH264DpbSlotInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_DECODE_H264_DPB_SLOT_INFO_KHR

    • VUID-VkVideoDecodeH264DpbSlotInfoKHR-pStdReferenceInfo-parameter
      pStdReferenceInfo must be a valid pointer to a valid StdVideoDecodeH264ReferenceInfo value

    36.11.7. H.264 Decode Requirements

    This section describes the required H.264 decoding capabilities for physical devices that have at least one queue family that supports the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H264_BIT_KHR, as returned by vkGetPhysicalDeviceQueueFamilyProperties2 in VkQueueFamilyVideoPropertiesKHR::videoCodecOperations.

    Table 39. Required Video Std Header Versions
    Video Std Header Name Version

    vulkan_video_codec_h264std_decode

    1.0.0

    36.12. H.265 Decode Operations

    Video decode operations using an H.265 decode profile can be used to decode elementary video stream sequences compliant to the ITU-T H.265 Specification.

    Note

    Refer to the Preamble for information on how the Khronos Intellectual Property Rights Policy relates to normative references to external materials not created by Khronos.

    This process is performed according to the video decode operation steps with the codec-specific semantics defined in section 8 of ITU-T H.265 Specification:

    If the parameters and the bitstream adhere to the syntactic and semantic requirements defined in the corresponding sections of the ITU-T H.265 Specification, as described above, and the DPB slots associated with the active reference pictures all refer to valid picture references, then the video decode operation will complete successfully. Otherwise, the video decode operation may complete unsuccessfully.

    36.12.1. H.265 Decode Bitstream Data Access

    The video bitstream buffer range should contain a VCL NAL unit comprised of the slice segment headers and data of a picture representing a frame, as defined in sections 7.3.6 and 7.3.8, and this data is interpreted as defined in sections 7.4.7 and 7.4.9 of the ITU-T H.265 Specification, respectively.

    The offsets provided in VkVideoDecodeH265PictureInfoKHR::pSliceSegmentOffsets should specify the starting offsets corresponding to each slice segment header within the video bitstream buffer range.

    36.12.2. H.265 Decode Picture Data Access

    Accesses to image data within a video picture resource happen at the granularity indicated by VkVideoCapabilitiesKHR::pictureAccessGranularity, as returned by vkGetPhysicalDeviceVideoCapabilitiesKHR for the used video profile. Accordingly, the complete image subregion of a decode output picture, reference picture, or reconstructed picture accessed by video coding operations using an H.265 decode profile is defined as the set of texels within the coordinate range:

    ([0,endX),[0,endY))

    Where:

    • endX equals codedExtent.width rounded up to the nearest integer multiple of pictureAccessGranularity.width and clamped to the width of the image subresource referred to by the corresponding VkVideoPictureResourceInfoKHR structure;

    • endY equals codedExtent.height rounded up to the nearest integer multiple of pictureAccessGranularity.height and clamped to the height of the image subresource referred to by the corresponding VkVideoPictureResourceInfoKHR structure;

    Where codedExtent is the member of the VkVideoPictureResourceInfoKHR structure corresponding to the picture.

    In case of video decode operations using an H.265 decode profile, any access to a picture at the coordinates (x,y), as defined by the ITU-T H.265 Specification, is an access to the image subresource referred to by the corresponding VkVideoPictureResourceInfoKHR structure at the texel coordinates (x,y).

    36.12.3. H.265 Decode Profile

    A video profile supporting H.265 video decode operations is specified by setting VkVideoProfileInfoKHR::videoCodecOperation to VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR and adding a VkVideoDecodeH265ProfileInfoKHR structure to the VkVideoProfileInfoKHR::pNext chain.

    The VkVideoDecodeH265ProfileInfoKHR structure is defined as:

    // Provided by VK_KHR_video_decode_h265
typedef struct VkVideoDecodeH265ProfileInfoKHR {
    VkStructureType           sType;
    const void*               pNext;
    StdVideoH265ProfileIdc    stdProfileIdc;
} VkVideoDecodeH265ProfileInfoKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • stdProfileIdc is a StdVideoH265ProfileIdc value specifying the H.265 codec profile IDC, as defined in section A3 of the ITU-T H.265 Specification.

    Valid Usage (Implicit)

    • VUID-VkVideoDecodeH265ProfileInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_DECODE_H265_PROFILE_INFO_KHR

    36.12.4. H.265 Decode Capabilities

    When calling vkGetPhysicalDeviceVideoCapabilitiesKHR to query the capabilities for an H.265 decode profile, the VkVideoCapabilitiesKHR::pNext chain must include a VkVideoDecodeH265CapabilitiesKHR structure that will be filled with the profile-specific capabilities.

    The VkVideoDecodeH265CapabilitiesKHR structure is defined as:

    // Provided by VK_KHR_video_decode_h265
typedef struct VkVideoDecodeH265CapabilitiesKHR {
    VkStructureType         sType;
    void*                   pNext;
    StdVideoH265LevelIdc    maxLevelIdc;
} VkVideoDecodeH265CapabilitiesKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • maxLevelIdc is a StdVideoH265LevelIdc value specifying the maximum H.265 level supported by the profile, as defined in section A.4 of the ITU-T H.265 Specification.

    Valid Usage (Implicit)

    • VUID-VkVideoDecodeH265CapabilitiesKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_DECODE_H265_CAPABILITIES_KHR

    36.12.5. H.265 Decode Parameter Sets

    Video session parameters objects created with the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR can contain the following types of parameters:

    H.265 Video Parameter Sets (VPS)

    Represented by StdVideoH265VideoParameterSet structures and interpreted as follows:

    • reserved1, reserved2, and reserved3 are used only for padding purposes and are otherwise ignored;

    • vps_video_parameter_set_id is used as the key of the VPS entry;

    • the max_latency_increase_plus1, max_dec_pic_buffering_minus1, and max_num_reorder_pics members of the StdVideoH265DecPicBufMgr structure pointed to by pDecPicBufMgr correspond to vps_max_latency_increase_plus1, vps_max_dec_pic_buffering_minus1, and vps_max_num_reorder_pics, respectively, as defined in section 7.4.3.1 of the ITU-T H.265 Specification;

    • the StdVideoH265HrdParameters structure pointed to by pHrdParameters is interpreted as follows:

      • reserved is used only for padding purposes and is otherwise ignored;

      • flags.fixed_pic_rate_general_flag is a bitmask where bit index i corresponds to fixed_pic_rate_general_flag[i] as defined in section E.3.2 of the ITU-T H.265 Specification;

      • flags.fixed_pic_rate_within_cvs_flag is a bitmask where bit index i corresponds to fixed_pic_rate_within_cvs_flag[i] as defined in section E.3.2 of the ITU-T H.265 Specification;

      • flags.low_delay_hrd_flag is a bitmask where bit index i corresponds to low_delay_hrd_flag[i] as defined in section E.3.2 of the ITU-T H.265 Specification;

      • if flags.nal_hrd_parameters_present_flag is set, then pSubLayerHrdParametersNal points to an array of vps_max_sub_layers_minus1 + 1 number of StdVideoH265SubLayerHrdParameters structures where vps_max_sub_layers_minus1 is the corresponding member of the encompassing StdVideoH265VideoParameterSet structure and each element is interpreted as follows:

        • cbr_flag is a bitmask where bit index i corresponds to cbr_flag[i] as defined in section E.3.3 of the ITU-T H.265 Specification;

        • all other members of the StdVideoH265SubLayerHrdParameters structure are interpreted as defined in section E.3.3 of the ITU-T H.265 Specification;

      • if flags.vcl_hrd_parameters_present_flag is set, then pSubLayerHrdParametersVcl points to an array of vps_max_sub_layers_minus1 + 1 number of StdVideoH265SubLayerHrdParameters structures where vps_max_sub_layers_minus1 is the corresponding member of the encompassing StdVideoH265VideoParameterSet structure and each element is interpreted as follows:

        • cbr_flag is a bitmask where bit index i corresponds to cbr_flag[i] as defined in section E.3.3 of the ITU-T H.265 Specification;

        • all other members of the StdVideoH265SubLayerHrdParameters structure are interpreted as defined in section E.3.3 of the ITU-T H.265 Specification;

      • all other members of StdVideoH265HrdParameters are interpreted as defined in section E.3.2 of the ITU-T H.265 Specification;

    • the members of the StdVideoH265ProfileTierLevel structure pointed to by pProfileTierLevel are interpreted as defined in section 7.4.4 of the ITU-T H.265 Specification;

    • all other members of StdVideoH265VideoParameterSet are interpreted as defined in section 7.4.3.1 of the ITU-T H.265 Specification.

    H.265 Sequence Parameter Sets (SPS)

    Represented by StdVideoH265SequenceParameterSet structures and interpreted as follows:

    • reserved1 and reserved2 are used only for padding purposes and are otherwise ignored;

    • the pair constructed from sps_video_parameter_set_id and sps_seq_parameter_set_id is used as the key of the SPS entry;

    • the members of the StdVideoH265ProfileTierLevel structure pointed to by pProfileTierLevel are interpreted as defined in section 7.4.4 of the ITU-T H.265 Specification;

    • the max_latency_increase_plus1, max_dec_pic_buffering_minus1, and max_num_reorder_pics members of the StdVideoH265DecPicBufMgr structure pointed to by pDecPicBufMgr correspond to sps_max_latency_increase_plus1, sps_max_dec_pic_buffering_minus1, and sps_max_num_reorder_pics, respectively, as defined in section 7.4.3.2 of the ITU-T H.265 Specification;

    • if flags.sps_scaling_list_data_present_flag is set, then the StdVideoH265ScalingLists structure pointed to by pScalingLists is interpreted as follows:

      • ScalingList4x4, ScalingList8x8, ScalingList16x16, and ScalingList32x32 correspond to ScalingList[0], ScalingList[1], ScalingList[2], and ScalingList[3], respectively, as defined in section 7.3.4 of the ITU-T H.265 Specification;

      • ScalingListDCCoef16x16 and ScalingListDCCoef32x32 correspond to scaling_list_dc_coef_minus8[0] and scaling_list_dc_coef_minus8[1], respectively, as defined in section 7.3.4 of the ITU-T H.265 Specification;

    • pShortTermRefPicSet points to an array of num_short_term_ref_pic_sets number of StdVideoH265ShortTermRefPicSet structures where each element is interpreted as follows:

      • reserved1, reserved2, and reserved3 are used only for padding purposes and are otherwise ignored;

      • used_by_curr_pic_flag is a bitmask where bit index i corresponds to used_by_curr_pic_flag[i] as defined in section 7.4.8 of the ITU-T H.265 Specification;

      • use_delta_flag is a bitmask where bit index i corresponds to use_delta_flag[i] as defined in section 7.4.8 of the ITU-T H.265 Specification;

      • used_by_curr_pic_s0_flag is a bitmask where bit index i corresponds to used_by_curr_pic_s0_flag[i] as defined in section 7.4.8 of the ITU-T H.265 Specification;

      • used_by_curr_pic_s1_flag is a bitmask where bit index i corresponds to used_by_curr_pic_s1_flag[i] as defined in section 7.4.8 of the ITU-T H.265 Specification;

      • all other members of StdVideoH265ShortTermRefPicSet are interpreted as defined in section 7.4.8 of the ITU-T H.265 Specification;

    • if flags.long_term_ref_pics_present_flag is set then the StdVideoH265LongTermRefPicsSps structure pointed to by pLongTermRefPicsSps is interpreted as follows:

      • used_by_curr_pic_lt_sps_flag is a bitmask where bit index i corresponds to used_by_curr_pic_lt_sps_flag[i] as defined in section 7.4.3.2 of the ITU-T H.265 Specification;

      • all other members of StdVideoH265LongTermRefPicsSps are interpreted as defined in section 7.4.3.2 of the ITU-T H.265 Specification;

    • if flags.vui_parameters_present_flag is set, then the StdVideoH265SequenceParameterSetVui structure pointed to by pSequenceParameterSetVui is interpreted as follows:

      • reserved1, reserved2, and reserved3 are used only for padding purposes and are otherwise ignored;

      • the StdVideoH265HrdParameters structure pointed to by pHrdParameters is interpreted as follows:

        • flags.fixed_pic_rate_general_flag is a bitmask where bit index i corresponds to fixed_pic_rate_general_flag[i] as defined in section E.3.2 of the ITU-T H.265 Specification;

        • flags.fixed_pic_rate_within_cvs_flag is a bitmask where bit index i corresponds to fixed_pic_rate_within_cvs_flag[i] as defined in section E.3.2 of the ITU-T H.265 Specification;

        • flags.low_delay_hrd_flag is a bitmask where bit index i corresponds to low_delay_hrd_flag[i] as defined in section E.3.2 of the ITU-T H.265 Specification;

        • if flags.nal_hrd_parameters_present_flag is set, then pSubLayerHrdParametersNal points to an array of sps_max_sub_layers_minus1 + 1 number of StdVideoH265SubLayerHrdParameters structures where sps_max_sub_layers_minus1 is the corresponding member of the encompassing StdVideoH265SequenceParameterSet structure and each element is interpreted as follows:

          • cbr_flag is a bitmask where bit index i corresponds to cbr_flag[i] as defined in section E.3.3 of the ITU-T H.265 Specification;

          • all other members of the StdVideoH265SubLayerHrdParameters structure are interpreted as defined in section E.3.3 of the ITU-T H.265 Specification;

        • if flags.vcl_hrd_parameters_present_flag is set, then pSubLayerHrdParametersVcl points to an array of sps_max_sub_layers_minus1 + 1 number of StdVideoH265SubLayerHrdParameters structures where sps_max_sub_layers_minus1 is the corresponding member of the encompassing StdVideoH265SequenceParameterSet structure and each element is interpreted as follows:

          • cbr_flag is a bitmask where bit index i corresponds to cbr_flag[i] as defined in section E.3.3 of the ITU-T H.265 Specification;

          • all other members of the StdVideoH265SubLayerHrdParameters structure are interpreted as defined in section E.3.3 of the ITU-T H.265 Specification;

        • all other members of StdVideoH265HrdParameters are interpreted as defined in section E.3.2 of the ITU-T H.265 Specification;

      • all other members of pSequenceParameterSetVui are interpreted as defined in section E.3.1 of the ITU-T H.265 Specification;

    • if flags.sps_palette_predictor_initializer_present_flag is set, then the PredictorPaletteEntries member of the StdVideoH265PredictorPaletteEntries structure pointed to by pPredictorPaletteEntries is interpreted as defined in section 7.4.9.13 of the ITU-T H.265 Specification;

    • all other members of StdVideoH265SequenceParameterSet are interpreted as defined in section 7.4.3.1 of the ITU-T H.265 Specification.

    H.265 Picture Parameter Sets (PPS)

    Represented by StdVideoH265PictureParameterSet structures and interpreted as follows:

    • reserved1, reserved2, and reserved3 are used only for padding purposes and are otherwise ignored;

    • the triplet constructed from sps_video_parameter_set_id, pps_seq_parameter_set_id, and pps_pic_parameter_set_id is used as the key of the PPS entry;

    • if flags.pps_scaling_list_data_present_flag is set, then the StdVideoH265ScalingLists structure pointed to by pScalingLists is interpreted as follows:

      • ScalingList4x4, ScalingList8x8, ScalingList16x16, and ScalingList32x32 correspond to ScalingList[0], ScalingList[1], ScalingList[2], and ScalingList[3], respectively, as defined in section 7.3.4 of the ITU-T H.265 Specification;

      • ScalingListDCCoef16x16 and ScalingListDCCoef32x32 correspond to scaling_list_dc_coef_minus8[0] and scaling_list_dc_coef_minus8[1], respectively, as defined in section 7.3.4 of the ITU-T H.265 Specification;

    • if flags.pps_palette_predictor_initializer_present_flag is set, then the PredictorPaletteEntries member of the StdVideoH265PredictorPaletteEntries structure pointed to by pPredictorPaletteEntries is interpreted as defined in section 7.4.9.13 of the ITU-T H.265 Specification;

    • all other members of StdVideoH265PictureParameterSet are interpreted as defined in section 7.4.3.3 of the ITU-T H.265 Specification.

    When a video session parameters object is created with the codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR, the VkVideoSessionParametersCreateInfoKHR::pNext chain must include a VkVideoDecodeH265SessionParametersCreateInfoKHR structure specifying the capacity and initial contents of the object.

    The VkVideoDecodeH265SessionParametersCreateInfoKHR structure is defined as:

    // Provided by VK_KHR_video_decode_h265
typedef struct VkVideoDecodeH265SessionParametersCreateInfoKHR {
    VkStructureType                                        sType;
    const void*                                            pNext;
    uint32_t                                               maxStdVPSCount;
    uint32_t                                               maxStdSPSCount;
    uint32_t                                               maxStdPPSCount;
    const VkVideoDecodeH265SessionParametersAddInfoKHR*    pParametersAddInfo;
} VkVideoDecodeH265SessionParametersCreateInfoKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • maxStdVPSCount is the maximum number of H.265 VPS entries the created VkVideoSessionParametersKHR can contain.

    • maxStdSPSCount is the maximum number of H.265 SPS entries the created VkVideoSessionParametersKHR can contain.

    • maxStdPPSCount is the maximum number of H.265 PPS entries the created VkVideoSessionParametersKHR can contain.

    • pParametersAddInfo is NULL or a pointer to a VkVideoDecodeH265SessionParametersAddInfoKHR structure specifying H.265 parameters to add upon object creation.

    Valid Usage (Implicit)

    • VUID-VkVideoDecodeH265SessionParametersCreateInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_DECODE_H265_SESSION_PARAMETERS_CREATE_INFO_KHR

    • VUID-VkVideoDecodeH265SessionParametersCreateInfoKHR-pParametersAddInfo-parameter
      If pParametersAddInfo is not NULL, pParametersAddInfo must be a valid pointer to a valid VkVideoDecodeH265SessionParametersAddInfoKHR structure

    The VkVideoDecodeH265SessionParametersAddInfoKHR structure is defined as:

    // Provided by VK_KHR_video_decode_h265
typedef struct VkVideoDecodeH265SessionParametersAddInfoKHR {
    VkStructureType                            sType;
    const void*                                pNext;
    uint32_t                                   stdVPSCount;
    const StdVideoH265VideoParameterSet*       pStdVPSs;
    uint32_t                                   stdSPSCount;
    const StdVideoH265SequenceParameterSet*    pStdSPSs;
    uint32_t                                   stdPPSCount;
    const StdVideoH265PictureParameterSet*     pStdPPSs;
} VkVideoDecodeH265SessionParametersAddInfoKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • stdVPSCount is the number of elements in the pStdVPSs array.

    • pStdVPSs is a pointer to an array of StdVideoH265VideoParameterSet structures describing the H.265 VPS entries to add.

    • stdSPSCount is the number of elements in the pStdSPSs array.

    • pStdSPSs is a pointer to an array of StdVideoH265SequenceParameterSet structures describing the H.265 SPS entries to add.

    • stdPPSCount is the number of elements in the pStdPPSs array.

    • pStdPPSs is a pointer to an array of StdVideoH265PictureParameterSet structures describing the H.265 PPS entries to add.

    This structure can be specified in the following places:

    Valid Usage

    • VUID-VkVideoDecodeH265SessionParametersAddInfoKHR-None-04833
      The vps_video_parameter_set_id member of each StdVideoH265VideoParameterSet structure specified in the elements of pStdVPSs must be unique within pStdVPSs

    • VUID-VkVideoDecodeH265SessionParametersAddInfoKHR-None-04834
      The pair constructed from the sps_video_parameter_set_id and sps_seq_parameter_set_id members of each StdVideoH265SequenceParameterSet structure specified in the elements of pStdSPSs must be unique within pStdSPSs

    • VUID-VkVideoDecodeH265SessionParametersAddInfoKHR-None-04835
      The triplet constructed from the sps_video_parameter_set_id, pps_seq_parameter_set_id, and pps_pic_parameter_set_id members of each StdVideoH265PictureParameterSet structure specified in the elements of pStdPPSs must be unique within pStdPPSs

    Valid Usage (Implicit)

    • VUID-VkVideoDecodeH265SessionParametersAddInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_DECODE_H265_SESSION_PARAMETERS_ADD_INFO_KHR

    • VUID-VkVideoDecodeH265SessionParametersAddInfoKHR-pStdVPSs-parameter
      If stdVPSCount is not 0, pStdVPSs must be a valid pointer to an array of stdVPSCount StdVideoH265VideoParameterSet values

    • VUID-VkVideoDecodeH265SessionParametersAddInfoKHR-pStdSPSs-parameter
      If stdSPSCount is not 0, pStdSPSs must be a valid pointer to an array of stdSPSCount StdVideoH265SequenceParameterSet values

    • VUID-VkVideoDecodeH265SessionParametersAddInfoKHR-pStdPPSs-parameter
      If stdPPSCount is not 0, pStdPPSs must be a valid pointer to an array of stdPPSCount StdVideoH265PictureParameterSet values

    36.12.6. H.265 Decoding Parameters

    The VkVideoDecodeH265PictureInfoKHR structure is defined as:

    // Provided by VK_KHR_video_decode_h265
typedef struct VkVideoDecodeH265PictureInfoKHR {
    VkStructureType                         sType;
    const void*                             pNext;
    const StdVideoDecodeH265PictureInfo*    pStdPictureInfo;
    uint32_t                                sliceSegmentCount;
    const uint32_t*                         pSliceSegmentOffsets;
} VkVideoDecodeH265PictureInfoKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • pStdPictureInfo is a pointer to a StdVideoDecodeH265PictureInfo structure specifying H.265 picture information.

    • sliceSegmentCount is the number of elements in pSliceSegmentOffsets.

    • pSliceSegmentOffsets is a pointer to an array of sliceSegmentCount offsets specifying the start offset of the slice segments of the picture within the video bitstream buffer range specified in VkVideoDecodeInfoKHR.

    This structure is specified in the pNext chain of the VkVideoDecodeInfoKHR structure passed to vkCmdDecodeVideoKHR to specify the codec-specific picture information for an H.265 decode operation.

    Decode Output Picture Information

    When this structure is specified in the pNext chain of the VkVideoDecodeInfoKHR structure passed to vkCmdDecodeVideoKHR, the information related to the decode output picture is defined as follows:

    Std Picture Information

    The members of the StdVideoDecodeH265PictureInfo structure pointed to by pStdPictureInfo are interpreted as follows:

    • reserved is used only for padding purposes and is otherwise ignored;

    • flags.IrapPicFlag as defined in section 3.73 of the ITU-T H.265 Specification;

    • flags.IdrPicFlag as defined in section 3.67 of the ITU-T H.265 Specification;

    • flags.IsReference as defined in section 3.132 of the ITU-T H.265 Specification;

    • sps_video_parameter_set_id, pps_seq_parameter_set_id, and pps_pic_parameter_set_id are used to identify the active parameter sets, as described below;

    • PicOrderCntVal as defined in section 8.3.1 of the ITU-T H.265 Specification;

    • NumBitsForSTRefPicSetInSlice is the number of bits used in st_ref_pic_set when short_term_ref_pic_set_sps_flag is 0, or 0 otherwise, as defined in sections 7.4.7 and 7.4.8 of the ITU-T H.265 Specification;

    • NumDeltaPocsOfRefRpsIdx is the value of NumDeltaPocs[RefRpsIdx] when short_term_ref_pic_set_sps_flag is 1, or 0 otherwise, as defined in sections 7.4.7 and 7.4.8 of the ITU-T H.265 Specification;

    • RefPicSetStCurrBefore, RefPicSetStCurrAfter, and RefPicSetLtCurr are interpreted as defined in section 8.3.2 of the ITU-T H.265 Specification where each element of these arrays either identifies an active reference picture using its DPB slot index or contains the value 0xFF to indicate "no reference picture";

    • all other members are interpreted as defined in section 8.3.2 of the ITU-T H.265 Specification.

    Active Parameter Sets

    The members of the StdVideoDecodeH265PictureInfo structure pointed to by pStdPictureInfo are used to select the active parameter sets to use from the bound video session parameters object, as follows:

    • The active VPS is the VPS identified by the key specified in StdVideoDecodeH265PictureInfo::sps_video_parameter_set_id.

    • The active SPS is the SPS identified by the key specified by the pair constructed from StdVideoDecodeH265PictureInfo::sps_video_parameter_set_id and StdVideoDecodeH265PictureInfo::pps_seq_parameter_set_id.

    • The active PPS is the PPS identified by the key specified by the triplet constructed from StdVideoDecodeH265PictureInfo::sps_video_parameter_set_id, StdVideoDecodeH265PictureInfo::pps_seq_parameter_set_id, and StdVideoDecodeH265PictureInfo::pps_pic_parameter_set_id.

    Valid Usage (Implicit)

    • VUID-VkVideoDecodeH265PictureInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_DECODE_H265_PICTURE_INFO_KHR

    • VUID-VkVideoDecodeH265PictureInfoKHR-pStdPictureInfo-parameter
      pStdPictureInfo must be a valid pointer to a valid StdVideoDecodeH265PictureInfo value

    • VUID-VkVideoDecodeH265PictureInfoKHR-pSliceSegmentOffsets-parameter
      pSliceSegmentOffsets must be a valid pointer to an array of sliceSegmentCount uint32_t values

    • VUID-VkVideoDecodeH265PictureInfoKHR-sliceSegmentCount-arraylength
      sliceSegmentCount must be greater than 0

    The VkVideoDecodeH265DpbSlotInfoKHR structure is defined as:

    // Provided by VK_KHR_video_decode_h265
typedef struct VkVideoDecodeH265DpbSlotInfoKHR {
    VkStructureType                           sType;
    const void*                               pNext;
    const StdVideoDecodeH265ReferenceInfo*    pStdReferenceInfo;
} VkVideoDecodeH265DpbSlotInfoKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • pStdReferenceInfo is a pointer to a StdVideoDecodeH265ReferenceInfo structure specifying reference picture information described in section 8.3 of the ITU-T H.265 Specification.

    This structure is specified in the pNext chain of VkVideoDecodeInfoKHR::pSetupReferenceSlot, if not NULL, and the pNext chain of the elements of VkVideoDecodeInfoKHR::pReferenceSlots to specify the codec-specific reference picture information for an H.265 decode operation.

    Active Reference Picture Information

    When this structure is specified in the pNext chain of the elements of VkVideoDecodeInfoKHR::pReferenceSlots, one element is added to the list of active reference pictures used by the video decode operation for each element of VkVideoDecodeInfoKHR::pReferenceSlots as follows:

    Reconstructed Picture Information

    When this structure is specified in the pNext chain of VkVideoDecodeInfoKHR::pSetupReferenceSlot, the information related to the reconstructed picture is defined as follows:

    Std Reference Information

    The members of the StdVideoDecodeH265ReferenceInfo structure pointed to by pStdReferenceInfo are interpreted as follows:

    • flags.used_for_long_term_reference is used to indicate whether the picture is marked as “used for long-term reference” as defined in section 8.3.2 of the ITU-T H.265 Specification;

    • flags.unused_for_reference is used to indicate whether the picture is marked as “unused for reference” as defined in section 8.3.2 of the ITU-T H.265 Specification;

    • all other members are interpreted as defined in section 8.3 of the ITU-T H.265 Specification.

    Valid Usage (Implicit)

    • VUID-VkVideoDecodeH265DpbSlotInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_DECODE_H265_DPB_SLOT_INFO_KHR

    • VUID-VkVideoDecodeH265DpbSlotInfoKHR-pStdReferenceInfo-parameter
      pStdReferenceInfo must be a valid pointer to a valid StdVideoDecodeH265ReferenceInfo value

    36.12.7. H.265 Decode Requirements

    This section describes the required H.265 decoding capabilities for physical devices that have at least one queue family that supports the video codec operation VK_VIDEO_CODEC_OPERATION_DECODE_H265_BIT_KHR, as returned by vkGetPhysicalDeviceQueueFamilyProperties2 in VkQueueFamilyVideoPropertiesKHR::videoCodecOperations.

    Table 40. Required Video Std Header Versions
    Video Std Header Name Version

    vulkan_video_codec_h265std_decode

    1.0.0

    36.13. Video Encode Operations

    Before the application can start recording Vulkan command buffers for the Video Encode Operations, it must do the following, beforehand:

    1. Ensure that the implementation can encode the Video Content by querying the supported codec operations and profiles using vkGetPhysicalDeviceQueueFamilyProperties2.

    2. By using vkGetPhysicalDeviceVideoFormatPropertiesKHR and providing one or more video profiles, choose the Vulkan formats supported by the implementation. The formats for input and reference pictures must be queried and chosen separately. Refer to the section on Video Format Capabilities.

    3. Before creating an image to be used as a video picture resource, obtain the supported image creation parameters by querying with vkGetPhysicalDeviceFormatProperties2 and vkGetPhysicalDeviceImageFormatProperties2 using one of the reported formats and adding VkVideoProfileListInfoKHR to the pNext chain of VkFormatProperties2. When querying the parameters with vkGetPhysicalDeviceImageFormatProperties2 for images targeting input and reference (DPB) pictures, the VkPhysicalDeviceImageFormatInfo2::usage field should contain VK_IMAGE_USAGE_VIDEO_ENCODE_SRC_BIT_KHR and VK_IMAGE_USAGE_VIDEO_ENCODE_DPB_BIT_KHR, respectively.

    4. Create none, some, or all of the required images for the input and reference pictures. More Video Picture Resources can be created at some later point if needed while processing the content to be encoded. Also, if the size of the picture to be encoded is expected to change, the images can be created based on the maximum expected content size.

    5. Create the video session to be used for video encode operations. Before creating the Encode Video Session, the encode capabilities should be queried with vkGetPhysicalDeviceVideoCapabilitiesKHR to obtain the limits of the parameters allowed by the implementation for a particular codec profile.

    6. Bind memory resources with the encode video session by calling vkBindVideoSessionMemoryKHR. The video session cannot be used until memory resources are allocated and bound to it. In order to determine the required memory sizes and heap types of the device memory allocations, vkGetVideoSessionMemoryRequirementsKHR should be called.

    7. Create one or more Video Session Parameter objects for use across command buffer recording operations, if required by the codec extension in use. These objects must be created against a video session with the parameters required by the codec. Each Video Session Parameter object created is a child object of the associated Session object and cannot be bound in the command buffer with any other Session Object.

    The recording of Video Encode Commands against a Vulkan Command Buffer consists of the following sequence:

    1. vkCmdBeginVideoCodingKHR starts the recording of one or more Video Encode operations in the command buffer. For each Video Encode Command operation, a Video Session must be bound to the command buffer within this command. This command establishes a Vulkan Video Encode Context that consists of the bound Video Session Object, Session Parameters Object, and the required Video Picture Resources. The established Video Encode Context is in effect until the vkCmdEndVideoCodingKHR command is recorded. If more Video Encode operations are to be required after the vkCmdEndVideoCodingKHR command, another Video Encode Context can be started with the vkCmdBeginVideoCodingKHR command.

    2. vkCmdEncodeVideoKHR specifies one or more frames to be encoded. The VkVideoEncodeInfoKHR parameters, and the codec extension structures chained to this, specify the details of the encode operation.

    3. vkCmdControlVideoCodingKHR records operations against the encoded data, encoding device, or the Video Session state.

    4. vkCmdEndVideoCodingKHR signals the end of the recording of the Vulkan Video Encode Context, as established by vkCmdBeginVideoCodingKHR.

    In addition to the above, the following commands can be recorded between vkCmdBeginVideoCodingKHR and vkCmdEndVideoCodingKHR:

    • Query operations

    • Global Memory Barriers

    • Buffer Memory Barriers

    • Image Memory Barriers (these must be used to transition the Video Picture Resources to the proper VK_IMAGE_LAYOUT_VIDEO_ENCODE_SRC_KHR and VK_IMAGE_LAYOUT_VIDEO_ENCODE_DPB_KHR layouts).

    • Pipeline Barriers

    • Events

    • Timestamps

    • Device Groups (device mask)

    The following Video Encode related commands must be recorded outside the Vulkan Video Encode Context established with the vkCmdBeginVideoCodingKHR and vkCmdEndVideoCodingKHR commands:

    • Sparse Memory Binding

    • Copy Commands

    • Clear Commands

    36.13.1. Encode Input Picture

    The primary source of input pixels for the video encoding process is the Encode Input Picture, represented by a VkImageView. It may also be a direct target of video decode, graphics, or compute operations , or with Window System Integration APIs .

    36.13.2. Capabilities

    When calling vkGetPhysicalDeviceVideoCapabilitiesKHR with pVideoProfile->videoCodecOperation specified as one of the encode operation bits, the VkVideoEncodeCapabilitiesKHR structure must be included in the pNext chain of the VkVideoCapabilitiesKHR structure to retrieve capabilities specific to video encoding.

    The VkVideoEncodeCapabilitiesKHR structure is defined as:

    // Provided by VK_KHR_video_encode_queue
typedef struct VkVideoEncodeCapabilitiesKHR {
    VkStructureType                         sType;
    void*                                   pNext;
    VkVideoEncodeCapabilityFlagsKHR         flags;
    VkVideoEncodeRateControlModeFlagsKHR    rateControlModes;
    uint32_t                                maxRateControlLayers;
    uint32_t                                maxQualityLevels;
    VkExtent2D                              inputImageDataFillAlignment;
    VkVideoEncodeFeedbackFlagsKHR           supportedEncodeFeedbackFlags;
} VkVideoEncodeCapabilitiesKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • flags is a bitmask of VkVideoEncodeCapabilityFlagBitsKHR describing supported encoding features.

    • rateControlModes is a bitmask of VkVideoEncodeRateControlModeFlagBitsKHR describing supported rate control modes.

    • maxRateControlLayers reports the maximum number of rate control layers supported. Implementations must report at least 1.

    • maxQualityLevels is the number of discrete quality levels supported. Implementations must report at least 1.

    • inputImageDataFillAlignment reports alignment of data that should be filled in the input image horizontally and vertically in pixels before encode operations are performed on the input image.

    • supportedEncodeFeedbackFlags is a bitmask of VkVideoEncodeFeedbackFlagBitsKHR values specifying the supported flags for video encode feedback queries.

    Implementations must include support for at least VK_VIDEO_ENCODE_FEEDBACK_BITSTREAM_BUFFER_OFFSET_BIT_KHR and VK_VIDEO_ENCODE_FEEDBACK_BITSTREAM_BYTES_WRITTEN_BIT_KHR in supportedEncodeFeedbackFlags.

    The input content and encode resolution (specified in VkVideoEncodeInfoKHR::codedExtent) may not be aligned with the codec-specific coding block size. For example, the input content may be 1920x1080 and the coding block size may be 16x16 pixel blocks. In this example, the content is horizontally aligned with the coding block size, but not vertically aligned with the coding block size. Encoding of the last row of blocks may be impacted by contents of the input image in pixel rows 1081 to 1088 (the next vertical alignment with the coding block size). In general, to ensure efficient encoding for the last row/column of blocks, and/or to ensure consistent encoding results between repeated encoding of the same input content, these extra pixel rows/columns should be filled to known values up to the coding block size alignment before encoding operations are performed. Some implementations support performing auto-fill of unaligned pixels beyond a specific alignment, which is reported in inputImageDataFillAlignment. For example, if an implementation reports 1x1 in inputImageDataFillAlignment, then the implementation will perform auto-fill for any unaligned pixels beyond the encode resolution up to the next coding block size. For a coding block size of 16x16, if the implementation reports 16x16 in inputImageDataFillAlignment, then it is the application’s responsibility to fill any unaligned pixels, if desired. If not, it may impact the encoding efficiency, but it will not affect the validity of the generated bitstream. If the implementation reports 8x8 in inputImageDataFillAlignment, then for the 1920x1080 example, since the content is aligned to 8 pixels vertically, the implementation will auto-fill pixel rows 1081 to 1088 (up to the 16x16 coding block size in the example). The auto-fill value(s) are implementation-specific. The auto-fill value(s) are not written to the input image memory, but are used as part of the encoding operation on the input image.

    Valid Usage (Implicit)

    • VUID-VkVideoEncodeCapabilitiesKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_ENCODE_CAPABILITIES_KHR

    // Provided by VK_KHR_video_encode_queue
typedef VkFlags VkVideoEncodeCapabilityFlagsKHR;

    VkVideoEncodeCapabilityFlagsKHR is a bitmask type for setting a mask of zero or more VkVideoEncodeCapabilityFlagBitsKHR.

    Bits which may be set in VkVideoEncodeCapabilitiesKHR::flags, indicating the encoding tools supported, are:

    // Provided by VK_KHR_video_encode_queue
typedef enum VkVideoEncodeCapabilityFlagBitsKHR {
    VK_VIDEO_ENCODE_CAPABILITY_PRECEDING_EXTERNALLY_ENCODED_BYTES_BIT_KHR = 0x00000001,
} VkVideoEncodeCapabilityFlagBitsKHR;

    • VK_VIDEO_ENCODE_CAPABILITY_PRECEDING_EXTERNALLY_ENCODED_BYTES_BIT_KHR reports that the implementation supports use of VkVideoEncodeInfoKHR::precedingExternallyEncodedBytes.

    36.13.3. Video Encode Commands

    To launch video encode operations, call:

    // Provided by VK_KHR_video_encode_queue
void vkCmdEncodeVideoKHR(
    VkCommandBuffer                             commandBuffer,
    const VkVideoEncodeInfoKHR*                 pEncodeInfo);

    • commandBuffer is the command buffer to be filled with this function for encoding to generate a bitstream.

    • pEncodeInfo is a pointer to a VkVideoEncodeInfoKHR structure.

    Each call issues one or more video encode operations. The implicit parameter opCount corresponds to the number of video encode operations issued by the command. After calling this command, the active query index of each active query is incremented by opCount.

    Currently each call to this command results in the issue of a single video encode operation.

    Valid Usage

    • VUID-vkCmdEncodeVideoKHR-opCount-07174
      For each active query, the active query index corresponding to the query type of that query plus opCount must be less than or equal to the last activatable query index corresponding to the query type of that query plus one

    Valid Usage (Implicit)

    • VUID-vkCmdEncodeVideoKHR-commandBuffer-parameter
      commandBuffer must be a valid VkCommandBuffer handle

    • VUID-vkCmdEncodeVideoKHR-pEncodeInfo-parameter
      pEncodeInfo must be a valid pointer to a valid VkVideoEncodeInfoKHR structure

    • VUID-vkCmdEncodeVideoKHR-commandBuffer-recording
      commandBuffer must be in the recording state

    • VUID-vkCmdEncodeVideoKHR-commandBuffer-cmdpool
      The VkCommandPool that commandBuffer was allocated from must support encode operations

    • VUID-vkCmdEncodeVideoKHR-renderpass
      This command must only be called outside of a render pass instance

    • VUID-vkCmdEncodeVideoKHR-videocoding
      This command must only be called inside of a video coding scope

    • VUID-vkCmdEncodeVideoKHR-bufferlevel
      commandBuffer must be a primary VkCommandBuffer

    Host Synchronization

    • Host access to commandBuffer must be externally synchronized

    • Host access to the VkCommandPool that commandBuffer was allocated from must be externally synchronized

    Command Properties
    Command Buffer Levels Render Pass Scope Video Coding Scope Supported Queue Types Command Type

    Primary

    Outside

    Inside

    Encode

    Action

    The VkVideoEncodeInfoKHR structure is defined as:

    // Provided by VK_KHR_video_encode_queue
typedef struct VkVideoEncodeInfoKHR {
    VkStructureType                       sType;
    const void*                           pNext;
    VkVideoEncodeFlagsKHR                 flags;
    uint32_t                              qualityLevel;
    VkBuffer                              dstBuffer;
    VkDeviceSize                          dstBufferOffset;
    VkDeviceSize                          dstBufferRange;
    VkVideoPictureResourceInfoKHR         srcPictureResource;
    const VkVideoReferenceSlotInfoKHR*    pSetupReferenceSlot;
    uint32_t                              referenceSlotCount;
    const VkVideoReferenceSlotInfoKHR*    pReferenceSlots;
    uint32_t                              precedingExternallyEncodedBytes;
} VkVideoEncodeInfoKHR;

    • sType is the type of this structure.

    • pNext is a pointer to a structure extending this structure. A codec-specific extension structure must be chained to specify what bitstream unit to generate with this encode operation.

    • flags is reserved for future use.

    • qualityLevel is the coding quality level of the encoding. It is defined by the codec-specific extensions.

    • dstBuffer is the destination video bitstream buffer to write the encoded bitstream to.

    • dstBufferOffset is the starting offset in bytes from the start of dstBuffer to write the encoded bitstream to. dstBufferOffset’s value must be aligned to VkVideoCapabilitiesKHR::minBitstreamBufferOffsetAlignment, as reported by the implementation.

    • dstBufferRange is the maximum size in bytes of the encoded bitstream written to dstBuffer, starting from dstBufferOffset. dstBufferRange’s value must be aligned to VkVideoCapabilitiesKHR::minBitstreamBufferSizeAlignment, as reported by the implementation.

    • srcPictureResource is the Picture Resource of the Input Picture to be encoded by the operation.

    • pSetupReferenceSlot is a pointer to a VkVideoReferenceSlotInfoKHR structure used for generating a reconstructed reference slot and Picture Resource. pSetupReferenceSlot->slotIndex specifies the slot index number to use as a target for producing the Reconstructed (DPB) data. pSetupReferenceSlot must be one of the entries provided in VkVideoBeginCodingInfoKHR via the pReferenceSlots within the vkCmdBeginVideoCodingKHR command that established the Vulkan Video Encode Context for this command.

    • referenceSlotCount is the number of Reconstructed Reference Pictures that will be used when this encoding operation is executing.

    • pReferenceSlots is NULL or a pointer to an array of VkVideoReferenceSlotInfoKHR structures that will be used when this encoding operation is executing. Each entry in pReferenceSlots must be one of the entries provided in VkVideoBeginCodingInfoKHR via the pReferenceSlots within the vkCmdBeginVideoCodingKHR command that established the Vulkan Video Encode Context for this command.

    • precedingExternallyEncodedBytes is the number of bytes externally encoded for insertion in the active video encode session overall bitstream prior to the bitstream that will be generated by the implementation for this instance of VkVideoEncodeInfoKHR. The value provided is used to update the implementation’s rate control algorithm for the rate control layer this instance of VkVideoEncodeInfoKHR belongs to, by accounting for the bitrate budget consumed by these externally encoded bytes. See VkVideoEncodeRateControlInfoKHR for additional information about encode rate control.

    The coded size of the encode operation is specified in codedExtent of srcPictureResource.

    Multiple vkCmdEncodeVideoKHR commands may be recorded within a Vulkan Video Encode Context. The execution of each vkCmdEncodeVideoKHR command will result in generating codec-specific bitstream units. These bitstream units are generated consecutively into the bitstream buffer specified in dstBuffer of a VkVideoEncodeInfoKHR structure within the vkCmdBeginVideoCodingKHR command. The produced bitstream is the sum of all these bitstream units, including any padding between the bitstream units. Any bitstream padding must be filled with data compliant to the codec standard so as not to cause any syntax errors during decoding of the bitstream units with the padding included. The range of the bitstream buffer written can be queried via video encode feedback queries.

    Valid Usage

    • VUID-VkVideoEncodeInfoKHR-None-07012
      The bound video session must not be in uninitialized state at the time the command is executed on the device

    Valid Usage (Implicit)

    • VUID-VkVideoEncodeInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_ENCODE_INFO_KHR

    • VUID-VkVideoEncodeInfoKHR-pNext-pNext
      pNext must be NULL

    • VUID-VkVideoEncodeInfoKHR-flags-zerobitmask
      flags must be 0

    • VUID-VkVideoEncodeInfoKHR-dstBuffer-parameter
      dstBuffer must be a valid VkBuffer handle

    • VUID-VkVideoEncodeInfoKHR-srcPictureResource-parameter
      srcPictureResource must be a valid VkVideoPictureResourceInfoKHR structure

    • VUID-VkVideoEncodeInfoKHR-pSetupReferenceSlot-parameter
      If pSetupReferenceSlot is not NULL, pSetupReferenceSlot must be a valid pointer to a valid VkVideoReferenceSlotInfoKHR structure

    • VUID-VkVideoEncodeInfoKHR-pReferenceSlots-parameter
      If referenceSlotCount is not 0, pReferenceSlots must be a valid pointer to an array of referenceSlotCount valid VkVideoReferenceSlotInfoKHR structures

    // Provided by VK_KHR_video_encode_queue
typedef VkFlags VkVideoEncodeFlagsKHR;

    VkVideoEncodeFlagsKHR is a bitmask type for setting a mask, but is currently reserved for future use.

    The VkVideoEncodeRateControlInfoKHR structure is defined as:

    // Provided by VK_KHR_video_encode_queue
typedef struct VkVideoEncodeRateControlInfoKHR {
    VkStructureType                                sType;
    const void*                                    pNext;
    VkVideoEncodeRateControlFlagsKHR               flags;
    VkVideoEncodeRateControlModeFlagBitsKHR        rateControlMode;
    uint32_t                                       layerCount;
    const VkVideoEncodeRateControlLayerInfoKHR*    pLayers;
} VkVideoEncodeRateControlInfoKHR;

    • sType is the type of this structure.

    • pNext is NULL or a pointer to a structure extending this structure.

    • flags is reserved for future use.

    • rateControlMode is a VkVideoEncodeRateControlModeFlagBitsKHR value specifying the encode stream rate control mode.

    • layerCount specifies the number of rate control layers in the video encode stream.

    • pLayers is a pointer to an array of VkVideoEncodeRateControlLayerInfoKHR structures specifying the rate control configurations of layerCount rate control layers.

    Including this structure in the pNext chain of VkVideoCodingControlInfoKHR and including VK_VIDEO_CODING_CONTROL_ENCODE_RATE_CONTROL_BIT_KHR in VkVideoCodingControlInfoKHR::flags will define stream rate control settings for video encoding.

    Additional structures providing codec-specific rate control parameters may need to be included in the pNext chain of VkVideoCodingControlInfoKHR depending on the codec profile the bound video session was created with and the parameters specified in VkVideoEncodeRateControlInfoKHR (see Video Coding Control).

    To ensure that the video session is properly initialized with stream-level rate control settings, the application must call vkCmdControlVideoCodingKHR with stream-level rate control settings at least once in execution order before the first vkCmdEncodeVideoKHR command that is executed after video session reset. If not provided, default implementation-specific stream rate control settings will be used.

    Stream rate control settings can also be re-initialized during an active video encoding session. The re-initialization takes effect whenever the VkVideoEncodeRateControlInfoKHR structure is included in the pNext chain of the VkVideoCodingControlInfoKHR structure in the call to vkCmdControlVideoCodingKHR, and only impacts vkCmdEncodeVideoKHR operations that follow in execution order.

    Valid Usage (Implicit)

    • VUID-VkVideoEncodeRateControlInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_ENCODE_RATE_CONTROL_INFO_KHR

    • VUID-VkVideoEncodeRateControlInfoKHR-flags-zerobitmask
      flags must be 0

    • VUID-VkVideoEncodeRateControlInfoKHR-rateControlMode-parameter
      If rateControlMode is not 0, rateControlMode must be a valid VkVideoEncodeRateControlModeFlagBitsKHR value

    • VUID-VkVideoEncodeRateControlInfoKHR-pLayers-parameter
      If layerCount is not 0, pLayers must be a valid pointer to an array of layerCount valid VkVideoEncodeRateControlLayerInfoKHR structures

    // Provided by VK_KHR_video_encode_queue
typedef VkFlags VkVideoEncodeRateControlFlagsKHR;

    VkVideoEncodeRateControlFlagsKHR is a bitmask type for setting a mask, but currently reserved for future use.

    The rate control modes are defined with the following enums:

    // Provided by VK_KHR_video_encode_queue
typedef enum VkVideoEncodeRateControlModeFlagBitsKHR {
    VK_VIDEO_ENCODE_RATE_CONTROL_MODE_DEFAULT_KHR = 0,
    VK_VIDEO_ENCODE_RATE_CONTROL_MODE_DISABLED_BIT_KHR = 0x00000001,
    VK_VIDEO_ENCODE_RATE_CONTROL_MODE_CBR_BIT_KHR = 0x00000002,
    VK_VIDEO_ENCODE_RATE_CONTROL_MODE_VBR_BIT_KHR = 0x00000004,
} VkVideoEncodeRateControlModeFlagBitsKHR;

    • VK_VIDEO_ENCODE_RATE_CONTROL_MODE_DEFAULT_KHR specifies the use of implementation-specific rate control.

    • VK_VIDEO_ENCODE_RATE_CONTROL_MODE_DISABLED_BIT_KHR specifies that rate control is disabled and any quality control parameters for the encoding are provided on a per-picture basis. In this mode implementations will encode pictures independently of the output bitrate of prior video encode operations.

    • VK_VIDEO_ENCODE_RATE_CONTROL_MODE_CBR_BIT_KHR specifies the use of constant bitrate rate control mode.

    • VK_VIDEO_ENCODE_RATE_CONTROL_MODE_VBR_BIT_KHR specifies the use of variable bitrate rate control mode.

    // Provided by VK_KHR_video_encode_queue
typedef VkFlags VkVideoEncodeRateControlModeFlagsKHR;

    VkVideoEncodeRateControlModeFlagsKHR is a bitmask type for setting a mask of zero or more VkVideoEncodeRateControlModeFlagBitsKHR.

    The VkVideoEncodeRateControlLayerInfoKHR structure is defined as:

    // Provided by VK_KHR_video_encode_queue
typedef struct VkVideoEncodeRateControlLayerInfoKHR {
    VkStructureType    sType;
    const void*        pNext;
    uint64_t           averageBitrate;
    uint64_t           maxBitrate;
    uint32_t           frameRateNumerator;
    uint32_t           frameRateDenominator;
    uint32_t           virtualBufferSizeInMs;
    uint32_t           initialVirtualBufferSizeInMs;
} VkVideoEncodeRateControlLayerInfoKHR;

    • sType is the type of this structure.

    • pNext is a pointer to a structure extending this structure.

    • averageBitrate is the average bitrate in bits/second. Valid when rate control mode is VK_VIDEO_ENCODE_RATE_CONTROL_MODE_CBR_BIT_KHR or VK_VIDEO_ENCODE_RATE_CONTROL_MODE_VBR_BIT_KHR.

    • maxBitrate is the peak bitrate in bits/second. Valid when rate control mode is VK_VIDEO_ENCODE_RATE_CONTROL_MODE_VBR_BIT_KHR.

    • frameRateNumerator is the numerator of the frame rate. Valid when rate control mode is VK_VIDEO_ENCODE_RATE_CONTROL_MODE_CBR_BIT_KHR or VK_VIDEO_ENCODE_RATE_CONTROL_MODE_VBR_BIT_KHR.

    • frameRateDenominator is the denominator of the frame rate. Valid when rate control mode is VK_VIDEO_ENCODE_RATE_CONTROL_MODE_CBR_BIT_KHR or VK_VIDEO_ENCODE_RATE_CONTROL_MODE_VBR_BIT_KHR.

    • virtualBufferSizeInMs is the leaky bucket model virtual buffer size in milliseconds, with respect to peak bitrate. Valid when rate control mode is VK_VIDEO_ENCODE_RATE_CONTROL_MODE_CBR_BIT_KHR or VK_VIDEO_ENCODE_RATE_CONTROL_MODE_VBR_BIT_KHR. For example, virtual buffer size is (virtualBufferSizeInMs × maxBitrate / 1000).

    • initialVirtualBufferSizeInMs is the initial occupancy in milliseconds of the virtual buffer in the leaky bucket model. Valid when rate control mode is VK_VIDEO_ENCODE_RATE_CONTROL_MODE_CBR_BIT_KHR or VK_VIDEO_ENCODE_RATE_CONTROL_MODE_VBR_BIT_KHR.

    A codec-specific structure specifying additional per-layer rate control settings must be chained to VkVideoEncodeRateControlLayerInfoKHR. If multiple rate control layers are enabled (VkVideoEncodeRateControlInfoKHR::layerCount is greater than 1), then the chained codec-specific extension structure also identifies the specific video coding layer its parent VkVideoEncodeRateControlLayerInfoKHR applies to. If multiple rate control layers are enabled, the number of rate control layers must match the number of video coding layers. The specification for an encode codec-specific extension would describe how multiple video coding layers are enabled for the corresponding codec.

    Per-layer rate control settings for all enabled rate control layers must be initialized or re-initialized whenever stream rate control settings are provided via VkVideoEncodeRateControlInfoKHR. This is done by specifying settings for all enabled rate control layers in VkVideoEncodeRateControlInfoKHR::pLayers.

    Including this structure in the pNext chain of VkVideoCodingControlInfoKHR and including VK_VIDEO_CODING_CONTROL_ENCODE_RATE_CONTROL_LAYER_BIT_KHR in VkVideoCodingControlInfoKHR::flags will define stream rate control settings for individual layers during video encoding. This adjustment only impacts the specified layer without impacting the rate control settings or implementation rate control algorithm behavior for any other enabled rate control layers. The adjustment takes effect whenever the corresponding vkCmdControlVideoCodingKHR is executed, and only impacts vkCmdEncodeVideoKHR operations pertaining to the corresponding video coding layer that follow in execution order.

    It is possible for an application to enable multiple video coding layers (via codec-specific extensions to encoding operations) while only enabling a single layer of rate control for the entire video stream. To achieve this, layerCount in VkVideoEncodeRateControlInfoKHR must be set to 1, and the single VkVideoEncodeRateControlLayerInfoKHR provided in pLayers would apply to all encoded segments of the video stream, regardless of which codec-defined video coding layer they belong to. In this case, the implementation decides bitrate distribution across video coding layers (if applicable to the specified stream rate control mode).

    Valid Usage (Implicit)

    • VUID-VkVideoEncodeRateControlLayerInfoKHR-sType-sType
      sType must be VK_STRUCTURE_TYPE_VIDEO_ENCODE_RATE_CONTROL_LAYER_INFO_KHR