// Copyright 2015-2022 The Khronos Group Inc. // // SPDX-License-Identifier: CC-BY-4.0 [appendix] [[compressed_image_formats]] = Compressed Image Formats The compressed texture formats used by Vulkan are described in the specifically identified sections of the <>, version 1.3. Unless otherwise described, the quantities encoded in these compressed formats are treated as normalized, unsigned values. Those formats listed as sRGB-encoded have in-memory representations of [eq]#R#, [eq]#G# and [eq]#B# components which are nonlinearly-encoded as [eq]#R'#, [eq]#G'#, and [eq]#B'#; any alpha component is unchanged. As part of filtering, the nonlinear [eq]#R'#, [eq]#G'#, and [eq]#B'# values are converted to linear [eq]#R#, [eq]#G#, and [eq]#B# components; any alpha component is unchanged. The conversion between linear and nonlinear encoding is performed as described in the "`KHR_DF_TRANSFER_SRGB`" section of the Khronos Data Format Specification. <<< [[appendix-compressedtex-bc]] == Block-Compressed Image Formats BC1, BC2 and BC3 formats are described in "`S3TC Compressed Texture Image Formats`" chapter of the <>. BC4 and BC5 are described in the "`RGTC Compressed Texture Image Formats`" chapter. BC6H and BC7 are described in the "`BPTC Compressed Texture Image Formats`" chapter. .Mapping of Vulkan BC formats to descriptions [width="90%",options="header",cols="5,4"] |==== | elink:VkFormat | <> description 2+^| Formats described in the "`S3TC Compressed Texture Image Formats`" chapter | ename:VK_FORMAT_BC1_RGB_UNORM_BLOCK |BC1 with no alpha | ename:VK_FORMAT_BC1_RGB_SRGB_BLOCK |BC1 with no alpha, sRGB-encoded | ename:VK_FORMAT_BC1_RGBA_UNORM_BLOCK|BC1 with alpha | ename:VK_FORMAT_BC1_RGBA_SRGB_BLOCK |BC1 with alpha, sRGB-encoded | ename:VK_FORMAT_BC2_UNORM_BLOCK |BC2 | ename:VK_FORMAT_BC2_SRGB_BLOCK |BC2, sRGB-encoded | ename:VK_FORMAT_BC3_UNORM_BLOCK |BC3 | ename:VK_FORMAT_BC3_SRGB_BLOCK |BC3, sRGB-encoded 2+^| Formats described in the "`RGTC Compressed Texture Image Formats`" chapter | ename:VK_FORMAT_BC4_UNORM_BLOCK |BC4 unsigned | ename:VK_FORMAT_BC4_SNORM_BLOCK |BC4 signed | ename:VK_FORMAT_BC5_UNORM_BLOCK |BC5 unsigned | ename:VK_FORMAT_BC5_SNORM_BLOCK |BC5 signed 2+^| Formats described in the "`BPTC Compressed Texture Image Formats`" chapter | ename:VK_FORMAT_BC6H_UFLOAT_BLOCK |BC6H (unsigned version) | ename:VK_FORMAT_BC6H_SFLOAT_BLOCK |BC6H (signed version) | ename:VK_FORMAT_BC7_UNORM_BLOCK |BC7 | ename:VK_FORMAT_BC7_SRGB_BLOCK |BC7, sRGB-encoded |==== <<< [[appendix-compressedtex-etc2]] == ETC Compressed Image Formats The following formats are described in the "`ETC2 Compressed Texture Image Formats`" chapter of the <>. .Mapping of Vulkan ETC formats to descriptions [options="header",cols="1,1"] |==== | elink:VkFormat | <> description | ename:VK_FORMAT_ETC2_R8G8B8_UNORM_BLOCK |RGB ETC2 | ename:VK_FORMAT_ETC2_R8G8B8_SRGB_BLOCK |RGB ETC2 with sRGB encoding | ename:VK_FORMAT_ETC2_R8G8B8A1_UNORM_BLOCK |RGB ETC2 with punch-through alpha | ename:VK_FORMAT_ETC2_R8G8B8A1_SRGB_BLOCK |RGB ETC2 with punch-through alpha and sRGB | ename:VK_FORMAT_ETC2_R8G8B8A8_UNORM_BLOCK |RGBA ETC2 | ename:VK_FORMAT_ETC2_R8G8B8A8_SRGB_BLOCK |RGBA ETC2 with sRGB encoding | ename:VK_FORMAT_EAC_R11_UNORM_BLOCK |Unsigned R11 EAC | ename:VK_FORMAT_EAC_R11_SNORM_BLOCK |Signed R11 EAC | ename:VK_FORMAT_EAC_R11G11_UNORM_BLOCK |Unsigned RG11 EAC | ename:VK_FORMAT_EAC_R11G11_SNORM_BLOCK |Signed RG11 EAC |==== <<< [[appendix-compressedtex-astc]] == ASTC Compressed Image Formats ASTC formats are described in the "`ASTC Compressed Texture Image Formats`" chapter of the <>. .Mapping of Vulkan ASTC formats to descriptions [width="90%",options="header",cols="55%,20%,25%"] |==== | elink:VkFormat ^| Compressed texel block dimensions ^| Requested mode | ename:VK_FORMAT_ASTC_4x4_UNORM_BLOCK ^|[eq]#4 {times} 4# ^|Linear LDR | ename:VK_FORMAT_ASTC_4x4_SRGB_BLOCK ^|[eq]#4 {times} 4# ^|sRGB | ename:VK_FORMAT_ASTC_5x4_UNORM_BLOCK ^|[eq]#5 {times} 4# ^|Linear LDR | ename:VK_FORMAT_ASTC_5x4_SRGB_BLOCK ^|[eq]#5 {times} 4# ^|sRGB | ename:VK_FORMAT_ASTC_5x5_UNORM_BLOCK ^|[eq]#5 {times} 5# ^|Linear LDR | ename:VK_FORMAT_ASTC_5x5_SRGB_BLOCK ^|[eq]#5 {times} 5# ^|sRGB | ename:VK_FORMAT_ASTC_6x5_UNORM_BLOCK ^|[eq]#6 {times} 5# ^|Linear LDR | ename:VK_FORMAT_ASTC_6x5_SRGB_BLOCK ^|[eq]#6 {times} 5# ^|sRGB | ename:VK_FORMAT_ASTC_6x6_UNORM_BLOCK ^|[eq]#6 {times} 6# ^|Linear LDR | ename:VK_FORMAT_ASTC_6x6_SRGB_BLOCK ^|[eq]#6 {times} 6# ^|sRGB | ename:VK_FORMAT_ASTC_8x5_UNORM_BLOCK ^|[eq]#8 {times} 5# ^|Linear LDR | ename:VK_FORMAT_ASTC_8x5_SRGB_BLOCK ^|[eq]#8 {times} 5# ^|sRGB | ename:VK_FORMAT_ASTC_8x6_UNORM_BLOCK ^|[eq]#8 {times} 6# ^|Linear LDR | ename:VK_FORMAT_ASTC_8x6_SRGB_BLOCK ^|[eq]#8 {times} 6# ^|sRGB | ename:VK_FORMAT_ASTC_8x8_UNORM_BLOCK ^|[eq]#8 {times} 8# ^|Linear LDR | ename:VK_FORMAT_ASTC_8x8_SRGB_BLOCK ^|[eq]#8 {times} 8# ^|sRGB | ename:VK_FORMAT_ASTC_10x5_UNORM_BLOCK ^|[eq]#10 {times} 5# ^|Linear LDR | ename:VK_FORMAT_ASTC_10x5_SRGB_BLOCK ^|[eq]#10 {times} 5# ^|sRGB | ename:VK_FORMAT_ASTC_10x6_UNORM_BLOCK ^|[eq]#10 {times} 6# ^|Linear LDR | ename:VK_FORMAT_ASTC_10x6_SRGB_BLOCK ^|[eq]#10 {times} 6# ^|sRGB | ename:VK_FORMAT_ASTC_10x8_UNORM_BLOCK ^|[eq]#10 {times} 8# ^|Linear LDR | ename:VK_FORMAT_ASTC_10x8_SRGB_BLOCK ^|[eq]#10 {times} 8# ^|sRGB | ename:VK_FORMAT_ASTC_10x10_UNORM_BLOCK ^|[eq]#10 {times} 10# ^|Linear LDR | ename:VK_FORMAT_ASTC_10x10_SRGB_BLOCK ^|[eq]#10 {times} 10# ^|sRGB | ename:VK_FORMAT_ASTC_12x10_UNORM_BLOCK ^|[eq]#12 {times} 10# ^|Linear LDR | ename:VK_FORMAT_ASTC_12x10_SRGB_BLOCK ^|[eq]#12 {times} 10# ^|sRGB | ename:VK_FORMAT_ASTC_12x12_UNORM_BLOCK ^|[eq]#12 {times} 12# ^|Linear LDR | ename:VK_FORMAT_ASTC_12x12_SRGB_BLOCK ^|[eq]#12 {times} 12# ^|sRGB ifdef::VK_VERSION_1_3,VK_EXT_texture_compression_astc_hdr[] | ename:VK_FORMAT_ASTC_4x4_SFLOAT_BLOCK ^|[eq]#4 {times} 4# ^|HDR | ename:VK_FORMAT_ASTC_5x4_SFLOAT_BLOCK ^|[eq]#5 {times} 4# ^|HDR | ename:VK_FORMAT_ASTC_5x5_SFLOAT_BLOCK ^|[eq]#5 {times} 5# ^|HDR | ename:VK_FORMAT_ASTC_6x5_SFLOAT_BLOCK ^|[eq]#6 {times} 5# ^|HDR | ename:VK_FORMAT_ASTC_6x6_SFLOAT_BLOCK ^|[eq]#6 {times} 6# ^|HDR | ename:VK_FORMAT_ASTC_8x5_SFLOAT_BLOCK ^|[eq]#8 {times} 5# ^|HDR | ename:VK_FORMAT_ASTC_8x6_SFLOAT_BLOCK ^|[eq]#8 {times} 6# ^|HDR | ename:VK_FORMAT_ASTC_8x8_SFLOAT_BLOCK ^|[eq]#8 {times} 8# ^|HDR | ename:VK_FORMAT_ASTC_10x5_SFLOAT_BLOCK ^|[eq]#10 {times} 5# ^|HDR | ename:VK_FORMAT_ASTC_10x6_SFLOAT_BLOCK ^|[eq]#10 {times} 6# ^|HDR | ename:VK_FORMAT_ASTC_10x8_SFLOAT_BLOCK ^|[eq]#10 {times} 8# ^|HDR | ename:VK_FORMAT_ASTC_10x10_SFLOAT_BLOCK ^|[eq]#10 {times} 10# ^|HDR | ename:VK_FORMAT_ASTC_12x10_SFLOAT_BLOCK ^|[eq]#12 {times} 10# ^|HDR | ename:VK_FORMAT_ASTC_12x12_SFLOAT_BLOCK ^|[eq]#12 {times} 12# ^|HDR endif::VK_VERSION_1_3,VK_EXT_texture_compression_astc_hdr[] |==== ifndef::VK_VERSION_1_3,VK_EXT_texture_compression_astc_hdr[] ASTC textures containing any HDR blocks should: not be passed into the API using an sRGB or UNORM texture format. endif::VK_VERSION_1_3,VK_EXT_texture_compression_astc_hdr[] ifdef::VK_VERSION_1_3,VK_EXT_texture_compression_astc_hdr[] ASTC textures containing HDR block encodings should: be passed to the API using an ASTC SFLOAT texture format. endif::VK_VERSION_1_3,VK_EXT_texture_compression_astc_hdr[] [NOTE] .Note ==== An HDR block in a texture passed using a LDR UNORM format will return the appropriate ASTC error color if the implementation supports only the ASTC LDR profile, but may result in either the error color or a decompressed HDR color if the implementation supports HDR decoding. ==== ifdef::VK_EXT_astc_decode_mode[] === ASTC decode mode If the `VK_EXT_astc_decode_mode` extension is enabled, the decode mode is determined as follows: .Mapping of Vulkan ASTC decoding format to ASTC decoding modes [width="75%",options="header",cols="75%,25%"] |==== | elink:VkFormat ^| Decoding mode | ename:VK_FORMAT_R16G16B16A16_SFLOAT ^| decode_float16 | ename:VK_FORMAT_R8G8B8A8_UNORM ^| decode_unorm8 | ename:VK_FORMAT_E5B9G9R9_UFLOAT_PACK32 ^| decode_rgb9e5 |==== Otherwise, the ASTC decode mode is decode_float16. Note that an implementation may: use HDR mode when linear LDR mode is requested unless the decode mode is decode_unorm8. endif::VK_EXT_astc_decode_mode[] ifndef::VK_EXT_astc_decode_mode[] The ASTC decode mode is decode_float16. Note that an implementation may: use HDR mode when linear LDR mode is requested. endif::VK_EXT_astc_decode_mode[] ifdef::VK_IMG_format_pvrtc[] <<< [[appendix-compressedtex-pvrtc]] == PVRTC Compressed Image Formats PVRTC formats are described in the "`PVRTC Compressed Texture Image Formats`" chapter of the <>. .Mapping of Vulkan PVRTC formats to descriptions [width="75%",options="header",cols="63%,15%,22%"] |==== | elink:VkFormat ^| Compressed texel block dimensions ^| sRGB-encoded | ename:VK_FORMAT_PVRTC1_2BPP_UNORM_BLOCK_IMG ^|[eq]#8 {times} 4# ^|No | ename:VK_FORMAT_PVRTC1_4BPP_UNORM_BLOCK_IMG ^|[eq]#4 {times} 4# ^|No | ename:VK_FORMAT_PVRTC2_2BPP_UNORM_BLOCK_IMG ^|[eq]#8 {times} 4# ^|No | ename:VK_FORMAT_PVRTC2_4BPP_UNORM_BLOCK_IMG ^|[eq]#4 {times} 4# ^|No | ename:VK_FORMAT_PVRTC1_2BPP_SRGB_BLOCK_IMG ^|[eq]#8 {times} 4# ^|Yes | ename:VK_FORMAT_PVRTC1_4BPP_SRGB_BLOCK_IMG ^|[eq]#4 {times} 4# ^|Yes | ename:VK_FORMAT_PVRTC2_2BPP_SRGB_BLOCK_IMG ^|[eq]#8 {times} 4# ^|Yes | ename:VK_FORMAT_PVRTC2_4BPP_SRGB_BLOCK_IMG ^|[eq]#4 {times} 4# ^|Yes |==== endif::VK_IMG_format_pvrtc[]