C Specification

Bits which can be set in VkQueryPoolVideoEncodeFeedbackCreateInfoKHR::encodeFeedbackFlags for video encode feedback query pools are:

// Provided by VK_KHR_video_encode_queue
typedef enum VkVideoEncodeFeedbackFlagBitsKHR {
    VK_VIDEO_ENCODE_FEEDBACK_BITSTREAM_BUFFER_OFFSET_BIT_KHR = 0x00000001,
    VK_VIDEO_ENCODE_FEEDBACK_BITSTREAM_BYTES_WRITTEN_BIT_KHR = 0x00000002,
    VK_VIDEO_ENCODE_FEEDBACK_BITSTREAM_HAS_OVERRIDES_BIT_KHR = 0x00000004,
} VkVideoEncodeFeedbackFlagBitsKHR;

Description

  • VK_VIDEO_ENCODE_FEEDBACK_BITSTREAM_BUFFER_OFFSET_BIT_KHR specifies that queries managed by the pool will capture the byte offset of the bitstream data written by the video encode operation to the bitstream buffer specified in VkVideoEncodeInfoKHR::dstBuffer relative to the offset specified in VkVideoEncodeInfoKHR::dstBufferOffset. For the first video encode operation issued by any video encode command, this value will always be zero, meaning that bitstream data is always written to the buffer specified in VkVideoEncodeInfoKHR::dstBuffer starting from the offset specified in VkVideoEncodeInfoKHR::dstBufferOffset.

  • VK_VIDEO_ENCODE_FEEDBACK_BITSTREAM_BYTES_WRITTEN_BIT_KHR specifies that queries managed by the pool will capture the number of bytes written by the video encode operation to the bitstream buffer specified in VkVideoEncodeInfoKHR::dstBuffer.

  • VK_VIDEO_ENCODE_FEEDBACK_BITSTREAM_HAS_OVERRIDES_BIT_KHR specifies that queries managed by the pool will capture a boolean value indicating that the data written to the bitstream buffer specified in VkVideoEncodeInfoKHR::dstBuffer contains overridden parameters.

When retrieving the results of video encode feedback queries, the values corresponding to each enabled video encode feedback are written in the order of the bits defined above, followed by an optional value indicating availability or result status if VK_QUERY_RESULT_WITH_AVAILABILITY_BIT or VK_QUERY_RESULT_WITH_STATUS_BIT_KHR is specified, respectively.

If the result status of a video encode feedback query is negative, then the results of all enabled video encode feedback values will be undefined.

Note

Thus it is recommended that applications always specify VK_QUERY_RESULT_WITH_STATUS_BIT_KHR when retrieving the results of video encode feedback queries and ignore such undefined video encode feedback values for any unsuccessfully completed video encode operations.

See Also

VK_KHR_video_encode_queue, VkVideoEncodeFeedbackFlagsKHR

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