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 *
y_range(nir_builder * b,nir_ssa_def * y_channel,int bpc,VkSamplerYcbcrRange range)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 *
chroma_range(nir_builder * b,nir_ssa_def * chroma_channel,int bpc,VkSamplerYcbcrRange range)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 *
ycbcr_model_to_rgb_matrix(VkSamplerYcbcrModelConversion model)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 *
nir_convert_ycbcr_to_rgb(nir_builder * b,VkSamplerYcbcrModelConversion model,VkSamplerYcbcrRange range,nir_ssa_def * raw_channels,uint32_t * bpcs)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 }
143