src/compiler/nir/nir_convert_ycbcr.c

   1 /*
   2  * Copyright © 2017 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  */
  23
  24 #include "nir_vulkan.h"
  25 #include <math.h>
  26
  27 static nir_ssa_def *
  28 y_range(nir_builder *b,
  29         nir_ssa_def *y_channel,
  30         int bpc,
  31         VkSamplerYcbcrRange range)
  32 {
  33    switch (range) {
  34    case VK_SAMPLER_YCBCR_RANGE_ITU_FULL:
  35       return y_channel;
  36    case VK_SAMPLER_YCBCR_RANGE_ITU_NARROW:
  37       return nir_fmul(b,
  38                       nir_fadd(b,
  39                                nir_fmul(b, y_channel,
  40                                         nir_imm_float(b, pow(2, bpc) - 1)),
  41                                nir_imm_float(b, -16.0f * pow(2, bpc - 8))),
  42                       nir_frcp(b, nir_imm_float(b, 219.0f * pow(2, bpc - 8))));
  43    default:
  44       unreachable("missing Ycbcr range");
  45       return NULL;
  46    }
  47 }
  48
  49 static nir_ssa_def *
  50 chroma_range(nir_builder *b,
  51              nir_ssa_def *chroma_channel,
  52              int bpc,
  53              VkSamplerYcbcrRange range)
  54 {
  55    switch (range) {
  56    case VK_SAMPLER_YCBCR_RANGE_ITU_FULL:
  57       return nir_fadd(b, chroma_channel,
  58                       nir_imm_float(b, -pow(2, bpc - 1) / (pow(2, bpc) - 1.0f)));
  59    case VK_SAMPLER_YCBCR_RANGE_ITU_NARROW:
  60       return nir_fmul(b,
  61                       nir_fadd(b,
  62                                nir_fmul(b, chroma_channel,
  63                                         nir_imm_float(b, pow(2, bpc) - 1)),
  64                                nir_imm_float(b, -128.0f * pow(2, bpc - 8))),
  65                       nir_frcp(b, nir_imm_float(b, 224.0f * pow(2, bpc - 8))));
  66    default:
  67       unreachable("missing Ycbcr range");
  68       return NULL;
  69    }
  70 }
  71
  72 typedef struct nir_const_value_3_4 {
  73    nir_const_value v[3][4];
  74 } nir_const_value_3_4;
  75
  76 static const nir_const_value_3_4 *
  77 ycbcr_model_to_rgb_matrix(VkSamplerYcbcrModelConversion model)
  78 {
  79    switch (model) {
  80    case VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_601: {
  81       static const nir_const_value_3_4 bt601 = { {
  82          { { .f32 =  1.402f             }, { .f32 = 1.0f }, { .f32 =  0.0f               }, { .f32 = 0.0f } },
  83          { { .f32 = -0.714136286201022f }, { .f32 = 1.0f }, { .f32 = -0.344136286201022f }, { .f32 = 0.0f } },
  84          { { .f32 =  0.0f               }, { .f32 = 1.0f }, { .f32 =  1.772f             }, { .f32 = 0.0f } },
  85       } };
  86
  87       return &bt601;
  88    }
  89    case VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_709: {
  90       static const nir_const_value_3_4 bt709 = { {
  91          { { .f32 =  1.5748031496063f   }, { .f32 = 1.0f }, { .f32 =  0.0f               }, { .f32 = 0.0f } },
  92          { { .f32 = -0.468125209181067f }, { .f32 = 1.0f }, { .f32 = -0.187327487470334f }, { .f32 = 0.0f } },
  93          { { .f32 =  0.0f               }, { .f32 = 1.0f }, { .f32 =  1.85563184264242f  }, { .f32 = 0.0f } },
  94       } };
  95
  96       return &bt709;
  97    }
  98    case VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_2020: {
  99       static const nir_const_value_3_4 bt2020 = { {
 100          { { .f32 =  1.4746f            }, { .f32 = 1.0f }, { .f32 =  0.0f               }, { .f32 = 0.0f } },
 101          { { .f32 = -0.571353126843658f }, { .f32 = 1.0f }, { .f32 = -0.164553126843658f }, { .f32 = 0.0f } },
 102          { { .f32 =  0.0f               }, { .f32 = 1.0f }, { .f32 =  1.8814f            }, { .f32 = 0.0f } },
 103       } };
 104
 105       return &bt2020;
 106    }
 107    default:
 108       unreachable("missing Ycbcr model");
 109       return NULL;
 110    }
 111 }
 112
 113 nir_ssa_def *
 114 nir_convert_ycbcr_to_rgb(nir_builder *b,
 115                          VkSamplerYcbcrModelConversion model,
 116                          VkSamplerYcbcrRange range,
 117                          nir_ssa_def *raw_channels,
 118                          uint32_t *bpcs)
 119 {
 120    nir_ssa_def *expanded_channels =
 121       nir_vec4(b,
 122                chroma_range(b, nir_channel(b, raw_channels, 0), bpcs[0], range),
 123                y_range(b, nir_channel(b, raw_channels, 1), bpcs[1], range),
 124                chroma_range(b, nir_channel(b, raw_channels, 2), bpcs[2], range),
 125                nir_channel(b, raw_channels, 3));
 126
 127    if (model == VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_IDENTITY)
 128       return expanded_channels;
 129
 130    const nir_const_value_3_4 *conversion_matrix =
 131       ycbcr_model_to_rgb_matrix(model);
 132
 133    nir_ssa_def *converted_channels[] = {
 134       nir_fdot4(b, expanded_channels, nir_build_imm(b, 4, 32, conversion_matrix->v[0])),
 135       nir_fdot4(b, expanded_channels, nir_build_imm(b, 4, 32, conversion_matrix->v[1])),
 136       nir_fdot4(b, expanded_channels, nir_build_imm(b, 4, 32, conversion_matrix->v[2]))
 137    };
 138
 139    return nir_vec4(b,
 140                    converted_channels[0], converted_channels[1],
 141                    converted_channels[2], nir_channel(b, raw_channels, 3));
 142 }