kc3-lang/angle/extensions/ANGLE_yuv_internal_format.txt

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• Author : Mohan Maiya
  Date : 2021-07-12 13:28:54
  Hash : e66e3344
  Message : Vulkan: Add GL_ANGLE_yuv_internal_format extension 1. Add a new extension to support creation of immutable textures with sized internal YUV formats 2. Rename YUV format enums from *_ANGLEX to *_ANGLE 3. Move YUV format enums from angleutils.h to glext_angle.h Bug: angleproject:5773 Change-Id: Ibfe732f4c9a4a536be56481f33e4768f6227c212 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2820153 Commit-Queue: Mohan Maiya <m.maiya@samsung.com> Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>

• extensions/ANGLE_yuv_internal_format.txt

• Name
  
      ANGLE_yuv_internal_format
  
  Name Strings
  
      GL_ANGLE_yuv_internal_format
  
  Contributors
  
      Mohan Maiya, Samsung
      Jamie Madill, Google
  
  Contacts
  
      Mohan Maiya, Samsung (m.maiya 'at' samsung 'dot' com)
  
  Notice
  
      Copyright (c) 2021 The Khronos Group Inc. Copyright terms at
          http://www.khronos.org/registry/speccopyright.html
  
  Status
  
      Draft.
  
  Version
  
      Version 5, June 23, 2021
  
  Number
  
      OpenGL ES Extension ###
  
  Dependencies
  
      OpenGL ES 3.0 is required.
  
  Overview
  
      This extension introduces a few sized internal YUV texture formats
      that can be used to create immutable textures using the TexStorage2D API.
      The only valid texture target supported is TEXTURE_2D, an INVALID_ENUM
      error is generated otherwise. There is no mipmap support and only NEAREST
      minification and magnification filters are supported.
  
      Support for the extension only requires the support of the commonly used 8-bit
      2-plane YUV format listed in the "New Tokens" section, refer to [fn1] for details
      about the formats and layout. It is up to the implementation to extend support
      for the other YUV formats.
  
      [fn1] : https://www.fourcc.org/yuv.php
  
  New Types
  
      None.
  
  New Procedures and Functions
  
      None.
  
  New Tokens
  
      List of non-standard YUV internal formats
  
      // 8-bit YUV formats
      G8_B8R8_2PLANE_420_UNORM_ANGLE                    0x96B1
      G8_B8_R8_3PLANE_420_UNORM_ANGLE                   0x96B2
  
      // 10-bit YUV formats
      G10X6_B10X6R10X6_2PLANE_420_UNORM_3PACK16_ANGLE   0x96B3
      G10X6_B10X6_R10X6_3PLANE_420_UNORM_3PACK16_ANGLE  0x96B4
  
      // 12-bit YUV formats
      G12X4_B12X4R12X4_2PLANE_420_UNORM_3PACK16_ANGLE   0x96B5
      G12X4_B12X4_R12X4_3PLANE_420_UNORM_3PACK16_ANGLE  0x96B6
  
      // 16-bit YUV formats
      G16_B16R16_2PLANE_420_UNORM_ANGLE                 0x96B7
      G16_B16_R16_3PLANE_420_UNORM_ANGLE                0x96B8
  
  
  Issues
  
      1. How was the new format list chosen?
  
         Commonly used planar YUV formats across various platforms were surveyed,
         including new platforms that support HDR content. A subset of those were
         chosen to be required. It is up to the implementations to extend support
         for the rest of the formats.
  
      2. What is the colorspace of image data of a texture created with the new formats?
  
         The texture or sampler parameter APIs can be expanded to indicate the colorspace
         in a layered extension and is outside the scope of this extension. The colorspace
         for textures with the above YUV formats is assumed to be ITU-R BT.601 with YUV
         values in limited range. Refer to ITU-R BT.601 spec for further details.
  
  Revision History
  
      #5 - (June 23, 2021) Mohan Maiya
           Renamed format enums from *_ANGLEX to *_ANGLE
  
      #4 - (June 23, 2021) Mohan Maiya
           Removed references to GL_OES_EGL_image_external
           and restricted the spec to simply introducing new
           sized internal YUV formats. Also updated enum values
  
      #3 - (June 8, 2021) Mohan Maiya
           Clarification regarding default colorspace
  
      #2 - (May 10, 2021) Mohan Maiya
           Update overview section to specify support for
           immutable textures
  
      #1 - (April 10, 2021) Mohan Maiya
           Original draft