VkVideoDecodeH265PictureInfoKHR(3)

# VkVideoDecodeH265PictureInfoKHR(3) Manual Page

## Name

VkVideoDecodeH265PictureInfoKHR - Structure specifies H.265 picture information when decoding a frame

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## C Specification

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;

## Members

- `sType` is a VkStructureType value identifying 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.

## Description

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:

  - The image subregion used is determined according to the H.265 Decode Picture Data Access section.

  - The decode output picture is associated with the H.265 picture information provided in `pStdPictureInfo`.

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`

## See Also

VK_KHR_video_decode_h265, VkStructureType

## 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