# VkSamplerYcbcrModelConversion(3) Manual Page

## Name

VkSamplerYcbcrModelConversion - Color model component of a color space

## C Specification

VkSamplerYcbcrModelConversion defines the conversion from the source color model to the shader color model. Possible values are:

    typedef enum VkSamplerYcbcrModelConversion {
        VK_SAMPLER_YCBCR_MODEL_CONVERSION_RGB_IDENTITY = 0,
        VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_IDENTITY = 1,
        VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_709 = 2,
        VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_601 = 3,
        VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_2020 = 4,
        VK_SAMPLER_YCBCR_MODEL_CONVERSION_RGB_IDENTITY_KHR = VK_SAMPLER_YCBCR_MODEL_CONVERSION_RGB_IDENTITY,
        VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_IDENTITY_KHR = VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_IDENTITY,
        VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_709_KHR = VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_709,
        VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_601_KHR = VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_601,
        VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_2020_KHR = VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_2020,
        VK_SAMPLER_YCBCR_MODEL_CONVERSION_MAX_ENUM = 0x7FFFFFFF
    } VkSamplerYcbcrModelConversion;

or the equivalent

    typedef VkSamplerYcbcrModelConversion VkSamplerYcbcrModelConversionKHR;

## Description

- `VK_SAMPLER_YCBCR_MODEL_CONVERSION_RGB_IDENTITY` specifies that the input values to the conversion are unmodified.

- `VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_IDENTITY` specifies no model conversion but the inputs are range expanded as for Y′CBCR.

- `VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_709` specifies the color model conversion from Y′CBCR to R′G′B′ defined in BT.709 and described in the “BT.709 Y’CBCR conversion” section of the Khronos Data Format Specification.

- `VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_601` specifies the color model conversion from Y′CBCR to R′G′B′ defined in BT.601 and described in the “BT.601 Y’CBCR conversion” section of the Khronos Data Format Specification.

- `VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_2020` specifies the color model conversion from Y′CBCR to R′G′B′ defined in BT.2020 and described in the “BT.2020 Y’CBCR conversion” section of the Khronos Data Format Specification.

In the `VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_*` color models, for the input to the sampler Y′CBCR range expansion and model conversion:

- the Y (Y′ luma) channel corresponds to the G channel of an RGB image.

- the CB (CB or “U” blue color difference) channel corresponds to the B channel of an RGB image.

- the CR (CR or “V” red color difference) channel corresponds to the R channel of an RGB image.

- the alpha channel, if present, is not modified by color model conversion.

These rules reflect the mapping of channels after the channel swizzle operation (controlled by VkSamplerYcbcrConversionCreateInfo::`components`).

| Note For example, an “YUVA” 32-bit format comprising four 8-bit channels can be implemented as `VK_FORMAT_R8G8B8A8_UNORM` with a component mapping: `components.a` = `VK_COMPONENT_SWIZZLE_IDENTITY` `components.r` = `VK_COMPONENT_SWIZZLE_B` `components.g` = `VK_COMPONENT_SWIZZLE_R` `components.b` = `VK_COMPONENT_SWIZZLE_G`

## See Also

VkAndroidHardwareBufferFormatPropertiesANDROID, VkSamplerYcbcrConversionCreateInfo

## 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.