C Specification

Encoded parameter data can be retrieved from a video session parameters object created with a video encode operation using the command:

// Provided by VK_KHR_video_encode_queue
VkResult vkGetEncodedVideoSessionParametersKHR(
    VkDevice                                    device,
    const VkVideoEncodeSessionParametersGetInfoKHR* pVideoSessionParametersInfo,
    VkVideoEncodeSessionParametersFeedbackInfoKHR* pFeedbackInfo,
    size_t*                                     pDataSize,
    void*                                       pData);

Parameters

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

  • pVideoSessionParametersInfo is a pointer to a VkVideoEncodeSessionParametersGetInfoKHR structure specifying the parameters of the encoded parameter data to retrieve.

  • pFeedbackInfo is either NULL or a pointer to a VkVideoEncodeSessionParametersFeedbackInfoKHR structure in which feedback about the requested parameter data is returned.

  • pDataSize is a pointer to a size_t value related to the amount of encode parameter data returned, as described below.

  • pData is either NULL or a pointer to a buffer to write the encoded parameter data to.

Description

If pData is NULL, then the size of the encoded parameter data, in bytes, that can be retrieved is returned in pDataSize. Otherwise, pDataSize must point to a variable set by the application to the size of the buffer, in bytes, pointed to by pData, and on return the variable is overwritten with the number of bytes actually written to pData. If pDataSize is less than the size of the encoded parameter data that can be retrieved, then no data will be written to pData, zero will be written to pDataSize, and VK_INCOMPLETE will be returned instead of VK_SUCCESS, to indicate that no encoded parameter data was returned.

If pFeedbackInfo is not NULL then the members of the VkVideoEncodeSessionParametersFeedbackInfoKHR structure and any additional structures included in its pNext chain that are applicable to the video session parameters object specified in pVideoSessionParametersInfo->videoSessionParameters will be filled with feedback about the requested parameter data on all successful calls to this command.

Note

This includes the cases when pData is NULL or when VK_INCOMPLETE is returned by the command, and enables the application to determine whether the implementation overrode any of the requested video session parameters without actually needing to retrieve the encoded parameter data itself.
Valid Usage

  • VUID-vkGetEncodedVideoSessionParametersKHR-pVideoSessionParametersInfo-08359
    pVideoSessionParametersInfo->videoSessionParameters must have been created with an encode operation

  • VUID-vkGetEncodedVideoSessionParametersKHR-pVideoSessionParametersInfo-08262
    If pVideoSessionParametersInfo->videoSessionParameters was created with the video codec operation VK_VIDEO_CODEC_OPERATION_ENCODE_H264_BIT_KHR, then the pNext chain of pVideoSessionParametersInfo must include a VkVideoEncodeH264SessionParametersGetInfoKHR structure

  • VUID-vkGetEncodedVideoSessionParametersKHR-pVideoSessionParametersInfo-08263
    If pVideoSessionParametersInfo->videoSessionParameters was created with the video codec operation VK_VIDEO_CODEC_OPERATION_ENCODE_H264_BIT_KHR, then for the VkVideoEncodeH264SessionParametersGetInfoKHR structure included in the pNext chain of pVideoSessionParametersInfo, if its writeStdSPS member is VK_TRUE, then pVideoSessionParametersInfo->videoSessionParameters must contain a StdVideoH264SequenceParameterSet entry with seq_parameter_set_id matching VkVideoEncodeH264SessionParametersGetInfoKHR::stdSPSId

  • VUID-vkGetEncodedVideoSessionParametersKHR-pVideoSessionParametersInfo-08264
    If pVideoSessionParametersInfo->videoSessionParameters was created with the video codec operation VK_VIDEO_CODEC_OPERATION_ENCODE_H264_BIT_KHR, then for the VkVideoEncodeH264SessionParametersGetInfoKHR structure included in the pNext chain of pVideoSessionParametersInfo, if its writeStdPPS member is VK_TRUE, then pVideoSessionParametersInfo->videoSessionParameters must contain a StdVideoH264PictureParameterSet entry with seq_parameter_set_id and pic_parameter_set_id matching VkVideoEncodeH264SessionParametersGetInfoKHR::stdSPSId and VkVideoEncodeH264SessionParametersGetInfoKHR::stdPPSId, respectively

  • VUID-vkGetEncodedVideoSessionParametersKHR-pVideoSessionParametersInfo-08265
    If pVideoSessionParametersInfo->videoSessionParameters was created with the video codec operation VK_VIDEO_CODEC_OPERATION_ENCODE_H265_BIT_KHR, then the pNext chain of pVideoSessionParametersInfo must include a VkVideoEncodeH265SessionParametersGetInfoKHR structure

  • VUID-vkGetEncodedVideoSessionParametersKHR-pVideoSessionParametersInfo-08266
    If pVideoSessionParametersInfo->videoSessionParameters was created with the video codec operation VK_VIDEO_CODEC_OPERATION_ENCODE_H265_BIT_KHR, then for the VkVideoEncodeH265SessionParametersGetInfoKHR structure included in the pNext chain of pVideoSessionParametersInfo, if its writeStdVPS member is VK_TRUE, then pVideoSessionParametersInfo->videoSessionParameters must contain a StdVideoH265VideoParameterSet entry with vps_video_parameter_set_id matching VkVideoEncodeH265SessionParametersGetInfoKHR::stdVPSId

  • VUID-vkGetEncodedVideoSessionParametersKHR-pVideoSessionParametersInfo-08267
    If pVideoSessionParametersInfo->videoSessionParameters was created with the video codec operation VK_VIDEO_CODEC_OPERATION_ENCODE_H265_BIT_KHR, then for the VkVideoEncodeH265SessionParametersGetInfoKHR structure included in the pNext chain of pVideoSessionParametersInfo, if its writeStdSPS member is VK_TRUE, then pVideoSessionParametersInfo->videoSessionParameters must contain a StdVideoH265SequenceParameterSet entry with sps_video_parameter_set_id and sps_seq_parameter_set_id matching VkVideoEncodeH265SessionParametersGetInfoKHR::stdVPSId and VkVideoEncodeH265SessionParametersGetInfoKHR::stdSPSId, respectively

  • VUID-vkGetEncodedVideoSessionParametersKHR-pVideoSessionParametersInfo-08268
    If pVideoSessionParametersInfo->videoSessionParameters was created with the video codec operation VK_VIDEO_CODEC_OPERATION_ENCODE_H265_BIT_KHR, then for the VkVideoEncodeH265SessionParametersGetInfoKHR structure included in the pNext chain of pVideoSessionParametersInfo, if its writeStdPPS member is VK_TRUE, then pVideoSessionParametersInfo->videoSessionParameters must contain a StdVideoH265PictureParameterSet entry with sps_video_parameter_set_id, pps_seq_parameter_set_id, and pps_pic_parameter_set_id matching VkVideoEncodeH265SessionParametersGetInfoKHR::stdVPSId, VkVideoEncodeH265SessionParametersGetInfoKHR::stdSPSId, and VkVideoEncodeH265SessionParametersGetInfoKHR::stdPPSId, respectively

Valid Usage (Implicit)

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

  • VUID-vkGetEncodedVideoSessionParametersKHR-pVideoSessionParametersInfo-parameter
    pVideoSessionParametersInfo must be a valid pointer to a valid VkVideoEncodeSessionParametersGetInfoKHR structure

  • VUID-vkGetEncodedVideoSessionParametersKHR-pFeedbackInfo-parameter
    If pFeedbackInfo is not NULL, pFeedbackInfo must be a valid pointer to a VkVideoEncodeSessionParametersFeedbackInfoKHR structure

  • VUID-vkGetEncodedVideoSessionParametersKHR-pDataSize-parameter
    pDataSize must be a valid pointer to a size_t value

  • VUID-vkGetEncodedVideoSessionParametersKHR-pData-parameter
    If the value referenced by pDataSize is not 0, and pData is not NULL, pData must be a valid pointer to an array of pDataSize bytes

Return Codes
On success, this command returns

  • VK_SUCCESS

  • VK_INCOMPLETE

On failure, this command returns

  • VK_ERROR_OUT_OF_HOST_MEMORY

  • VK_ERROR_OUT_OF_DEVICE_MEMORY

See Also

VK_KHR_video_encode_queue, VkDevice, VkVideoEncodeSessionParametersFeedbackInfoKHR, VkVideoEncodeSessionParametersGetInfoKHR

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 2014-2024 The Khronos Group Inc.

SPDX-License-Identifier: CC-BY-4.0