# VkImageViewASTCDecodeModeEXT(3) Manual Page

## Name

VkImageViewASTCDecodeModeEXT - Structure describing the ASTC decode mode for an image view

## C Specification

If the `pNext` list includes a `VkImageViewASTCDecodeModeEXT` structure, then that structure includes a parameter specifying the decode mode for image views using ASTC compressed formats.

The `VkImageViewASTCDecodeModeEXT` structure is defined as:

    typedef struct VkImageViewASTCDecodeModeEXT {
        VkStructureType    sType;
        const void*        pNext;
        VkFormat           decodeMode;
    } VkImageViewASTCDecodeModeEXT;

## Members

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to an extension-specific structure.

- `decodeMode` is the intermediate format used to decode ASTC compressed formats.

## Description

Valid Usage

- `decodeMode` must be one of `VK_FORMAT_R16G16B16A16_SFLOAT`, `VK_FORMAT_R8G8B8A8_UNORM`, or `VK_FORMAT_E5B9G9R9_UFLOAT_PACK32`

- If the `decodeModeSharedExponent` feature is not enabled, `decodeMode` must not be `VK_FORMAT_E5B9G9R9_UFLOAT_PACK32`

- If `decodeMode` is `VK_FORMAT_R8G8B8A8_UNORM` the image view must not include blocks using any of the ASTC HDR modes

- `format` of the image view must be one of `VK_FORMAT_ASTC_4x4_UNORM_BLOCK`, `VK_FORMAT_ASTC_4x4_SRGB_BLOCK`, `VK_FORMAT_ASTC_5x4_UNORM_BLOCK`, `VK_FORMAT_ASTC_5x4_SRGB_BLOCK`, `VK_FORMAT_ASTC_5x5_UNORM_BLOCK`, `VK_FORMAT_ASTC_5x5_SRGB_BLOCK`, `VK_FORMAT_ASTC_6x5_UNORM_BLOCK`, `VK_FORMAT_ASTC_6x5_SRGB_BLOCK`, `VK_FORMAT_ASTC_6x6_UNORM_BLOCK`, `VK_FORMAT_ASTC_6x6_SRGB_BLOCK`, `VK_FORMAT_ASTC_8x5_UNORM_BLOCK`, `VK_FORMAT_ASTC_8x5_SRGB_BLOCK`, `VK_FORMAT_ASTC_8x6_UNORM_BLOCK`, `VK_FORMAT_ASTC_8x6_SRGB_BLOCK`, `VK_FORMAT_ASTC_8x8_UNORM_BLOCK`, `VK_FORMAT_ASTC_8x8_SRGB_BLOCK`, `VK_FORMAT_ASTC_10x5_UNORM_BLOCK`, `VK_FORMAT_ASTC_10x5_SRGB_BLOCK`, `VK_FORMAT_ASTC_10x6_UNORM_BLOCK`, `VK_FORMAT_ASTC_10x6_SRGB_BLOCK`, `VK_FORMAT_ASTC_10x8_UNORM_BLOCK`, `VK_FORMAT_ASTC_10x8_SRGB_BLOCK`, `VK_FORMAT_ASTC_10x10_UNORM_BLOCK`, `VK_FORMAT_ASTC_10x10_SRGB_BLOCK`, `VK_FORMAT_ASTC_12x10_UNORM_BLOCK`, `VK_FORMAT_ASTC_12x10_SRGB_BLOCK`, `VK_FORMAT_ASTC_12x12_UNORM_BLOCK`, or `VK_FORMAT_ASTC_12x12_SRGB_BLOCK`

If `format` uses sRGB encoding then the `decodeMode` has no effect.

Valid Usage (Implicit)

- `sType` must be `VK_STRUCTURE_TYPE_IMAGE_VIEW_ASTC_DECODE_MODE_EXT`

- `decodeMode` must be a valid VkFormat value

## See Also

VkFormat, 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 (c) 2014-2020 Khronos Group. This work is licensed under a Creative Commons Attribution 4.0 International License.