# VkVideoDecodeAV1PictureInfoKHR(3) Manual Page

## Name

VkVideoDecodeAV1PictureInfoKHR - Structure specifies AV1 picture information when decoding a frame

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## C Specification

The `VkVideoDecodeAV1PictureInfoKHR` structure is defined as:

    // Provided by VK_KHR_video_decode_av1
    typedef struct VkVideoDecodeAV1PictureInfoKHR {
        VkStructureType                        sType;
        const void*                            pNext;
        const StdVideoDecodeAV1PictureInfo*    pStdPictureInfo;
        int32_t                                referenceNameSlotIndices[VK_MAX_VIDEO_AV1_REFERENCES_PER_FRAME_KHR];
        uint32_t                               frameHeaderOffset;
        uint32_t                               tileCount;
        const uint32_t*                        pTileOffsets;
        const uint32_t*                        pTileSizes;
    } VkVideoDecodeAV1PictureInfoKHR;

## 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 `StdVideoDecodeAV1PictureInfo` structure specifying AV1 picture information.

- `referenceNameSlotIndices` is an array of seven (`VK_MAX_VIDEO_AV1_REFERENCES_PER_FRAME_KHR`, which is equal to the Video Std definition `STD_VIDEO_AV1_REFS_PER_FRAME`) signed integer values specifying the index of the DPB slot or a negative integer value for each AV1 reference name used for inter coding. In particular, the DPB slot index for the AV1 reference name `frame` is specified in `referenceNameSlotIndices`[`frame` - `STD_VIDEO_AV1_REFERENCE_NAME_LAST_FRAME`].

- `frameHeaderOffset` is the byte offset of the AV1 frame header OBU, as defined in section 5.9 of the AV1 Specification, within the video bitstream buffer range specified in VkVideoDecodeInfoKHR.

- `tileCount` is the number of elements in `pTileOffsets` and `pTileSizes`.

- `pTileOffsets` is a pointer to an array of `tileCount` integers specifying the byte offset of the tiles of the picture within the video bitstream buffer range specified in VkVideoDecodeInfoKHR.

- `pTileSizes` is a pointer to an array of `tileCount` integers specifying the byte size of the tiles 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 AV1 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 AV1 Decode Picture Data Access section.

  - The decode output picture is associated with the AV1 picture information provided in `pStdPictureInfo`.

Std Picture Information

  The members of the `StdVideoDecodeAV1PictureInfo` structure pointed to by `pStdPictureInfo` are interpreted as follows:

  - `flags.reserved`, `reserved1`, and `reserved2` are used only for padding purposes and are otherwise ignored;

  - `flags.apply_grain` indicates that film grain is enabled for the decoded picture, as defined in section 6.8.20 of the AV1 Specification;

  - `OrderHint`, `OrderHints`, and `expectedFrameId` are interpreted as defined in section 6.8.2 of the AV1 Specification;

  - the `StdVideoAV1TileInfo` structure pointed to by `pTileInfo` is interpreted as follows:

    - `flags.reserved` and `reserved1` are used only for padding purposes and are otherwise ignored;

    - `pMiColStarts` is a pointer to an array of `TileCols` number of unsigned integers that corresponds to `MiColStarts` defined in section 6.8.14 of the AV1 Specification;

    - `pMiRowStarts` is a pointer to an array of `TileRows` number of unsigned integers that corresponds to `MiRowStarts` defined in section 6.8.14 of the AV1 Specification;

    - `pWidthInSbsMinus1` is a pointer to an array of `TileCols` number of unsigned integers that corresponds to `width_in_sbs_minus_1` defined in section 6.8.14 of the AV1 Specification;

    - `pHeightInSbsMinus1` is a pointer to an array of `TileRows` number of unsigned integers that corresponds to `height_in_sbs_minus_1` defined in section 6.8.14 of the AV1 Specification;

    - all other members of `StdVideoAV1TileInfo` are interpreted as defined in section 6.8.14 of the AV1 Specification;

  - the `StdVideoAV1Quantization` structure pointed to by `pQuantization` is interpreted as follows:

    - `flags.reserved` is used only for padding purposes and is otherwise ignored;

    - all other members of `StdVideoAV1Quantization` are interpreted as defined in section 6.8.11 of the AV1 Specification;

  - if `flags.segmentation_enabled` is set, then the `StdVideoAV1Segmentation` structure pointed to by `pSegmentation` is interpreted as follows:

    - the elements of `FeatureEnabled` are bitmasks where bit index j of element i corresponds to `FeatureEnabled[i][j]` as defined in section 5.9.14 of the AV1 Specification;

    - `FeatureData` is interpreted as defined in section 5.9.14 of the AV1 Specification;

  - the `StdVideoAV1LoopFilter` structure pointed to by `pLoopFilter` is interpreted as follows:

    - `flags.reserved` is used only for padding purposes and is otherwise ignored;

    - `update_ref_delta` is a bitmask where bit index i is interpreted as the value of `update_ref_delta` corresponding to element i of `loop_filter_ref_deltas` as defined in section 6.8.10 of the AV1 Specification;

    - `update_mode_delta` is a bitmask where bit index i is interpreted as the value of `update_mode_delta` corresponding to element i of `loop_filter_mode_deltas` as defined in section 6.8.10 of the AV1 Specification;

    - all other members of `StdVideoAV1LoopFilter` are interpreted as defined in section 6.8.10 of the AV1 Specification;

      Note | If the syntax elements corresponding to `loop_filter_ref_deltas` and `loop_filter_mode_deltas` are not present or otherwise defined according to section 5.9.11 of the AV1 Specification, the application should specify the previous values, as defined in section 6.8.10 of the AV1 Specification.

  - if `flags.enable_cdef` is set in the active sequence header, then the members of the `StdVideoAV1CDEF` structure pointed to by `pCDEF` are interpreted as follows:

    - `cdef_y_sec_strength` and `cdef_uv_sec_strength` are the bitstream values of the corresponding syntax elements defined in section 5.9.19 of the AV1 Specification;

    - all other members of `StdVideoAV1CDEF` are interpreted as defined in section 6.10.14 of the AV1 Specification;

  - the `StdVideoAV1LoopRestoration` structure pointed to by `pLoopRestoration` is interpreted as follows:

    - `LoopRestorationSize`[`plane`] is interpreted as log2(`size`) - 5, where `size` is the value of `LoopRestorationSize`[`plane`] as defined in section 6.10.15 of the AV1 Specification.

    - all other members of `StdVideoAV1LoopRestoration` are defined as in section 6.10.15 of the AV1 Specification;

  - the members of the `StdVideoAV1GlobalMotion` structure provided in `global_motion` are interpreted as defined in section 7.10 of the AV1 Specification;

  - if `flags.film_grain_params_present` is set in the active sequence header, then the `StdVideoAV1FilmGrain` structure pointed to by `pFilmGrain` is interpreted as follows:

    - `flags.reserved` is used only for padding purposes and is otherwise ignored;

    - all other members of `StdVideoAV1FilmGrain` are interpreted as defined in section 6.8.20 of the AV1 Specification;

  - all other members are interpreted as defined in section 6.8 of the AV1 Specification.

When film grain is enabled for the decoded frame, the `flags.update_grain` and `film_grain_params_ref_idx` values specified in `StdVideoAV1FilmGrain` are ignored by AV1 decode operations and the `load_grain_params` function, as defined in section 6.8.20 of the AV1 Specification, is not executed. Instead, the application is responsible for specifying the effective film grain parameters for the frame in `StdVideoAV1FilmGrain`.

When film grain is enabled for the decoded frame, the application is required to specify a different decode output picture resource in VkVideoDecodeInfoKHR::`dstPictureResource` compared to the reconstructed picture specified in VkVideoDecodeInfoKHR::`pSetupReferenceSlot->pPictureResource` even if the implementation does not report support for `VK_VIDEO_DECODE_CAPABILITY_DPB_AND_OUTPUT_DISTINCT_BIT_KHR` in VkVideoDecodeCapabilitiesKHR::`flags` for the video decode profile.

Reference picture setup is controlled by the value of `StdVideoDecodeAV1PictureInfo`::`refresh_frame_flags`. If it is not zero and a reconstructed picture is specified, then the latter is used as the target of picture reconstruction to activate the DPB slot specified in `pDecodeInfo->pSetupReferenceSlot->slotIndex`. If `StdVideoDecodeAV1PictureInfo`::`refresh_frame_flags` is zero, but a reconstructed picture is specified, then the corresponding picture reference associated with the DPB slot is invalidated, as described in the DPB Slot States section.

Active Parameter Sets

  The active sequence header is the AV1 sequence header stored in the bound video session parameters object , unless the bound video session was created with `VK_VIDEO_SESSION_CREATE_INLINE_SESSION_PARAMETERS_BIT_KHR` and the active sequence header is specified inline. .

Valid Usage (Implicit)

- VUID-VkVideoDecodeAV1PictureInfoKHR-sType-sType
  `sType` must be `VK_STRUCTURE_TYPE_VIDEO_DECODE_AV1_PICTURE_INFO_KHR`

- VUID-VkVideoDecodeAV1PictureInfoKHR-pStdPictureInfo-parameter
  `pStdPictureInfo` must be a valid pointer to a valid `StdVideoDecodeAV1PictureInfo` value

- VUID-VkVideoDecodeAV1PictureInfoKHR-pTileOffsets-parameter
  `pTileOffsets` must be a valid pointer to an array of `tileCount` `uint32_t` values

- VUID-VkVideoDecodeAV1PictureInfoKHR-pTileSizes-parameter
  `pTileSizes` must be a valid pointer to an array of `tileCount` `uint32_t` values

- VUID-VkVideoDecodeAV1PictureInfoKHR-tileCount-arraylength
  `tileCount` must be greater than `0`

## See Also

VK_KHR_video_decode_av1, 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 2014-2025 The Khronos Group Inc.

SPDX-License-Identifier: CC-BY-4.0