C Specification

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;

Members

  • 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.

Description

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
    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 VkVideoEncodeH264VclFrameInfoEXT or VkVideoEncodeH265VclFrameInfoEXT

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

  • 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

See Also

VK_KHR_video_encode_queue, VkBuffer, VkDeviceSize, VkStructureType, VkVideoEncodeFlagsKHR, VkVideoPictureResourceInfoKHR, VkVideoReferenceSlotInfoKHR, vkCmdEncodeVideoKHR

Document Notes

For more information, see the Vulkan Specification

This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.

Copyright

Copyright 2014-2023 The Khronos Group Inc.

SPDX-License-Identifier: CC-BY-4.0