1 /*
2 * Copyright 2019 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8 #include "include/core/SkM44.h"
9 #include "src/core/SkYUVMath.h"
10
11 // in SkColorMatrix order (row-major)
12 // Created by running SkColorMatrix_DumpYUVMatrixTables()
13 const float JPEG_full_rgb_to_yuv[] = {
14 0.299000f, 0.587000f, 0.114000f, 0.000000f, 0.000000f,
15 -0.168736f, -0.331264f, 0.500000f, 0.000000f, 0.501961f,
16 0.500000f, -0.418688f, -0.081312f, 0.000000f, 0.501961f,
17 0.000000f, 0.000000f, 0.000000f, 1.000000f, 0.000000f,
18 };
19 const float JPEG_full_yuv_to_rgb[] = {
20 1.000000f, -0.000000f, 1.402000f, 0.000000f, -0.703749f,
21 1.000000f, -0.344136f, -0.714136f, 0.000000f, 0.531211f,
22 1.000000f, 1.772000f, 0.000000f, 0.000000f, -0.889475f,
23 0.000000f, 0.000000f, 0.000000f, 1.000000f, 0.000000f,
24 };
25 const float Rec601_limited_rgb_to_yuv[] = {
26 0.256788f, 0.504129f, 0.097906f, 0.000000f, 0.062745f,
27 -0.148223f, -0.290993f, 0.439216f, 0.000000f, 0.501961f,
28 0.439216f, -0.367788f, -0.071427f, 0.000000f, 0.501961f,
29 0.000000f, 0.000000f, 0.000000f, 1.000000f, 0.000000f,
30 };
31 const float Rec601_limited_yuv_to_rgb[] = {
32 1.164384f, -0.000000f, 1.596027f, 0.000000f, -0.874202f,
33 1.164384f, -0.391762f, -0.812968f, 0.000000f, 0.531668f,
34 1.164384f, 2.017232f, 0.000000f, 0.000000f, -1.085631f,
35 0.000000f, 0.000000f, 0.000000f, 1.000000f, 0.000000f,
36 };
37 const float Rec709_full_rgb_to_yuv[] = {
38 0.212600f, 0.715200f, 0.072200f, 0.000000f, 0.000000f,
39 -0.114572f, -0.385428f, 0.500000f, 0.000000f, 0.501961f,
40 0.500000f, -0.454153f, -0.045847f, 0.000000f, 0.501961f,
41 0.000000f, 0.000000f, 0.000000f, 1.000000f, 0.000000f,
42 };
43 const float Rec709_full_yuv_to_rgb[] = {
44 1.000000f, -0.000000f, 1.574800f, 0.000000f, -0.790488f,
45 1.000000f, -0.187324f, -0.468124f, 0.000000f, 0.329010f,
46 1.000000f, 1.855600f, -0.000000f, 0.000000f, -0.931439f,
47 0.000000f, 0.000000f, 0.000000f, 1.000000f, 0.000000f,
48 };
49 const float Rec709_limited_rgb_to_yuv[] = {
50 0.182586f, 0.614231f, 0.062007f, 0.000000f, 0.062745f,
51 -0.100644f, -0.338572f, 0.439216f, 0.000000f, 0.501961f,
52 0.439216f, -0.398942f, -0.040274f, 0.000000f, 0.501961f,
53 0.000000f, 0.000000f, 0.000000f, 1.000000f, 0.000000f,
54 };
55 const float Rec709_limited_yuv_to_rgb[] = {
56 1.164384f, -0.000000f, 1.792741f, 0.000000f, -0.972945f,
57 1.164384f, -0.213249f, -0.532909f, 0.000000f, 0.301483f,
58 1.164384f, 2.112402f, -0.000000f, 0.000000f, -1.133402f,
59 0.000000f, 0.000000f, 0.000000f, 1.000000f, 0.000000f,
60 };
61 const float BT2020_8bit_full_rgb_to_yuv[] = {
62 0.262700f, 0.678000f, 0.059300f, 0.000000f, 0.000000f,
63 -0.139630f, -0.360370f, 0.500000f, 0.000000f, 0.501961f,
64 0.500000f, -0.459786f, -0.040214f, 0.000000f, 0.501961f,
65 0.000000f, 0.000000f, 0.000000f, 1.000000f, 0.000000f,
66 };
67 const float BT2020_8bit_full_yuv_to_rgb[] = {
68 1.000000f, -0.000000f, 1.474600f, 0.000000f, -0.740191f,
69 1.000000f, -0.164553f, -0.571353f, 0.000000f, 0.369396f,
70 1.000000f, 1.881400f, -0.000000f, 0.000000f, -0.944389f,
71 0.000000f, 0.000000f, 0.000000f, 1.000000f, 0.000000f,
72 };
73 const float BT2020_8bit_limited_rgb_to_yuv[] = {
74 0.225613f, 0.582282f, 0.050928f, 0.000000f, 0.062745f,
75 -0.122655f, -0.316560f, 0.439216f, 0.000000f, 0.501961f,
76 0.439216f, -0.403890f, -0.035326f, 0.000000f, 0.501961f,
77 0.000000f, 0.000000f, 0.000000f, 1.000000f, 0.000000f,
78 };
79 const float BT2020_8bit_limited_yuv_to_rgb[] = {
80 1.164384f, -0.000000f, 1.678674f, 0.000000f, -0.915688f,
81 1.164384f, -0.187326f, -0.650424f, 0.000000f, 0.347458f,
82 1.164384f, 2.141772f, -0.000000f, 0.000000f, -1.148145f,
83 0.000000f, 0.000000f, 0.000000f, 1.000000f, 0.000000f,
84 };
85 const float BT2020_10bit_full_rgb_to_yuv[] = {
86 0.262700f, 0.678000f, 0.059300f, 0.000000f, 0.000000f,
87 -0.139630f, -0.360370f, 0.500000f, 0.000000f, 0.500489f,
88 0.500000f, -0.459786f, -0.040214f, 0.000000f, 0.500489f,
89 0.000000f, 0.000000f, 0.000000f, 1.000000f, 0.000000f,
90 };
91 const float BT2020_10bit_full_yuv_to_rgb[] = {
92 1.000000f, -0.000000f, 1.474600f, 0.000000f, -0.738021f,
93 1.000000f, -0.164553f, -0.571353f, 0.000000f, 0.368313f,
94 1.000000f, 1.881400f, -0.000000f, 0.000000f, -0.941620f,
95 0.000000f, 0.000000f, 0.000000f, 1.000000f, 0.000000f,
96 };
97 const float BT2020_10bit_limited_rgb_to_yuv[] = {
98 0.224951f, 0.580575f, 0.050779f, 0.000000f, 0.062561f,
99 -0.122296f, -0.315632f, 0.437928f, 0.000000f, 0.500489f,
100 0.437928f, -0.402706f, -0.035222f, 0.000000f, 0.500489f,
101 0.000000f, 0.000000f, 0.000000f, 1.000000f, 0.000000f,
102 };
103 const float BT2020_10bit_limited_yuv_to_rgb[] = {
104 1.167808f, -0.000000f, 1.683611f, 0.000000f, -0.915688f,
105 1.167808f, -0.187877f, -0.652337f, 0.000000f, 0.347458f,
106 1.167808f, 2.148072f, -0.000000f, 0.000000f, -1.148145f,
107 0.000000f, 0.000000f, 0.000000f, 1.000000f, 0.000000f,
108 };
109 const float BT2020_12bit_full_rgb_to_yuv[] = {
110 0.262700f, 0.678000f, 0.059300f, 0.000000f, 0.000000f,
111 -0.139630f, -0.360370f, 0.500000f, 0.000000f, 0.500122f,
112 0.500000f, -0.459786f, -0.040214f, 0.000000f, 0.500122f,
113 0.000000f, 0.000000f, 0.000000f, 1.000000f, 0.000000f,
114 };
115 const float BT2020_12bit_full_yuv_to_rgb[] = {
116 1.000000f, -0.000000f, 1.474600f, 0.000000f, -0.737480f,
117 1.000000f, -0.164553f, -0.571353f, 0.000000f, 0.368043f,
118 1.000000f, 1.881400f, -0.000000f, 0.000000f, -0.940930f,
119 0.000000f, 0.000000f, 0.000000f, 1.000000f, 0.000000f,
120 };
121 const float BT2020_12bit_limited_rgb_to_yuv[] = {
122 0.224787f, 0.580149f, 0.050742f, 0.000000f, 0.062515f,
123 -0.122206f, -0.315401f, 0.437607f, 0.000000f, 0.500122f,
124 0.437607f, -0.402411f, -0.035196f, 0.000000f, 0.500122f,
125 0.000000f, 0.000000f, 0.000000f, 1.000000f, 0.000000f,
126 };
127 const float BT2020_12bit_limited_yuv_to_rgb[] = {
128 1.168664f, -0.000000f, 1.684846f, 0.000000f, -0.915688f,
129 1.168664f, -0.188015f, -0.652816f, 0.000000f, 0.347458f,
130 1.168664f, 2.149647f, -0.000000f, 0.000000f, -1.148145f,
131 0.000000f, 0.000000f, 0.000000f, 1.000000f, 0.000000f,
132 };
133
134 static_assert(kJPEG_Full_SkYUVColorSpace == 0, "");
135 static_assert(kRec601_Limited_SkYUVColorSpace == 1, "");
136 static_assert(kRec709_Full_SkYUVColorSpace == 2, "");
137 static_assert(kRec709_Limited_SkYUVColorSpace == 3, "");
138 static_assert(kBT2020_8bit_Full_SkYUVColorSpace == 4, "");
139 static_assert(kBT2020_8bit_Limited_SkYUVColorSpace == 5, "");
140 static_assert(kBT2020_10bit_Full_SkYUVColorSpace == 6, "");
141 static_assert(kBT2020_10bit_Limited_SkYUVColorSpace == 7, "");
142 static_assert(kBT2020_12bit_Full_SkYUVColorSpace == 8, "");
143 static_assert(kBT2020_12bit_Limited_SkYUVColorSpace == 9, "");
144
145 const float* yuv_to_rgb_array[] = {
146 JPEG_full_yuv_to_rgb,
147 Rec601_limited_yuv_to_rgb,
148 Rec709_full_yuv_to_rgb,
149 Rec709_limited_yuv_to_rgb,
150 BT2020_8bit_full_yuv_to_rgb,
151 BT2020_8bit_limited_yuv_to_rgb,
152 BT2020_10bit_full_yuv_to_rgb,
153 BT2020_10bit_limited_yuv_to_rgb,
154 BT2020_12bit_full_yuv_to_rgb,
155 BT2020_12bit_limited_yuv_to_rgb,
156 };
157
158 const float* rgb_to_yuv_array[] = {
159 JPEG_full_rgb_to_yuv,
160 Rec601_limited_rgb_to_yuv,
161 Rec709_full_rgb_to_yuv,
162 Rec709_limited_rgb_to_yuv,
163 BT2020_8bit_full_rgb_to_yuv,
164 BT2020_8bit_limited_rgb_to_yuv,
165 BT2020_10bit_full_rgb_to_yuv,
166 BT2020_10bit_limited_rgb_to_yuv,
167 BT2020_12bit_full_rgb_to_yuv,
168 BT2020_12bit_limited_rgb_to_yuv,
169 };
170
171 constexpr size_t kSizeOfColorMatrix = 20 * sizeof(float);
172
SkColorMatrix_RGB2YUV(SkYUVColorSpace cs,float m[20])173 void SkColorMatrix_RGB2YUV(SkYUVColorSpace cs, float m[20]) {
174 if ((unsigned)cs < (unsigned)kIdentity_SkYUVColorSpace) {
175 memcpy(m, rgb_to_yuv_array[(unsigned)cs], kSizeOfColorMatrix);
176 } else {
177 memset(m, 0, kSizeOfColorMatrix);
178 m[0] = m[6] = m[12] = m[18] = 1;
179 }
180 }
181
SkColorMatrix_YUV2RGB(SkYUVColorSpace cs,float m[20])182 void SkColorMatrix_YUV2RGB(SkYUVColorSpace cs, float m[20]) {
183 if ((unsigned)cs < (unsigned)kIdentity_SkYUVColorSpace) {
184 memcpy(m, yuv_to_rgb_array[(unsigned)cs], kSizeOfColorMatrix);
185 } else {
186 memset(m, 0, kSizeOfColorMatrix);
187 m[0] = m[6] = m[12] = m[18] = 1;
188 }
189 }
190
191 ///////////////////////////////////////////////////////////////////////////////////////////////////
192
193 // we just drop the alpha rol/col from the colormatrix
194 // output is | tr |
195 // | 3x3 tg |
196 // | tb |
197 // | 0 0 0 1 |
colormatrix_to_matrix44(const float src[20],SkM44 * dst)198 static void colormatrix_to_matrix44(const float src[20], SkM44* dst) {
199 *dst = SkM44(src[ 0], src[ 1], src[ 2], src[ 4],
200 src[ 5], src[ 6], src[ 7], src[ 9],
201 src[10], src[11], src[12], src[14],
202 0, 0, 0, 1);
203 }
204
205 // input: ignore the bottom row
206 // output: inject identity row/column for alpha
matrix44_to_colormatrix(const SkM44 & src,float dst[20])207 static void matrix44_to_colormatrix(const SkM44& src, float dst[20]) {
208 dst[0] = src.rc(0,0);
209 dst[1] = src.rc(0,1);
210 dst[2] = src.rc(0,2);
211 dst[3] = 0;
212 dst[4] = src.rc(0,3); // tx
213
214 dst[5] = src.rc(1,0);
215 dst[6] = src.rc(1,1);
216 dst[7] = src.rc(1,2);
217 dst[8] = 0;
218 dst[9] = src.rc(1,3); // ty
219
220 dst[10] = src.rc(2,0);
221 dst[11] = src.rc(2,1);
222 dst[12] = src.rc(2,2);
223 dst[13] = 0;
224 dst[14] = src.rc(2,3); // tz
225
226 dst[15] = dst[16] = dst[17] = dst[19] = 0;
227 dst[18] = 1;
228 }
229
scale3(float m[],float s)230 static void scale3(float m[], float s) {
231 for (int i = 0; i < 3; ++i) {
232 m[i] *= s;
233 }
234 }
235
236 namespace {
237 enum Range { kFull, kLimited };
238 struct YUVCoeff {
239 float Kr, Kb;
240 int bits;
241 Range range;
242 };
243
244 const YUVCoeff gCoeff[] = {
245 { 0.2990f, 0.1140f, 8, kFull }, // kJPEG_Full_SkYUVColorSpace
246 { 0.2990f, 0.1140f, 8, kLimited }, // kRec601_Limited_SkYUVColorSpace
247 { 0.2126f, 0.0722f, 8, kFull }, // kRec709_Full_SkYUVColorSpace
248 { 0.2126f, 0.0722f, 8, kLimited }, // kRec709_Limited_SkYUVColorSpace
249 { 0.2627f, 0.0593f, 8, kFull }, // kBT2020_8bit_Full_SkYUVColorSpace
250 { 0.2627f, 0.0593f, 8, kLimited }, // kBT2020_8bit_Limited_SkYUVColorSpace
251 { 0.2627f, 0.0593f, 10, kFull }, // kBT2020_10bit_Full_SkYUVColorSpace
252 { 0.2627f, 0.0593f, 10, kLimited }, // kBT2020_10bit_Limited_SkYUVColorSpace
253 { 0.2627f, 0.0593f, 12, kFull }, // kBT2020_12bit_Full_SkYUVColorSpace
254 { 0.2627f, 0.0593f, 12, kLimited }, // kBT2020_12bit_Limited_SkYUVColorSpace
255 };
256 } // namespace
257
make_rgb_to_yuv_matrix(float mx[20],const YUVCoeff & c)258 static void make_rgb_to_yuv_matrix(float mx[20], const YUVCoeff& c) {
259 SkASSERT(c.bits >= 8);
260 const float Kr = c.Kr;
261 const float Kb = c.Kb;
262 const float Kg = 1.0f - Kr - Kb;
263 const float Cr = 0.5f / (1.0f - Kb);
264 const float Cb = 0.5f / (1.0f - Kr);
265
266 const int shift = c.bits - 8;
267
268 const float denom = static_cast<float>((1 << c.bits) - 1);
269 float scaleY = 1.0f,
270 addY = 0.0f,
271 scaleUV = 1.0f,
272 addUV = (128 << shift) / denom;
273
274 if (c.range == kLimited) {
275 scaleY = (219 << shift) / denom;
276 addY = ( 16 << shift) / denom;
277 scaleUV = (224 << shift) / denom;
278 }
279
280 float m[20] = {
281 Kr, Kg, Kb, 0, addY,
282 -Kr, -Kg, 1-Kb, 0, addUV,
283 1-Kr, -Kg, -Kb, 0, addUV,
284 0, 0, 0, 1, 0,
285 };
286 memcpy(mx, m, sizeof(m));
287 scale3(mx + 0, scaleY );
288 scale3(mx + 5, Cr * scaleUV);
289 scale3(mx + 10, Cb * scaleUV);
290 }
291
dump(const float m[20],SkYUVColorSpace cs,bool rgb2yuv)292 static void dump(const float m[20], SkYUVColorSpace cs, bool rgb2yuv) {
293 const char* names[] = {
294 "JPEG_full",
295 "Rec601_limited",
296 "Rec709_full",
297 "Rec709_limited",
298 "BT2020_8bit_full",
299 "BT2020_8bit_limited",
300 "BT2020_10bit_full",
301 "BT2020_10bit_limited",
302 "BT2020_12bit_full",
303 "BT2020_12bit_limited",
304 };
305 const char* dirnames[] = {
306 "yuv_to_rgb", "rgb_to_yuv",
307 };
308 SkDebugf("const float %s_%s[] = {\n", names[cs], dirnames[rgb2yuv]);
309 for (int i = 0; i < 4; ++i) {
310 SkDebugf(" ");
311 for (int j = 0; j < 5; ++j) {
312 SkDebugf(" %9.6ff,", m[i * 5 + j]);
313 }
314 SkDebugf("\n");
315 }
316 SkDebugf("};\n");
317 }
318
319 // Used to create the prebuilt tables for each colorspace.
320 // Don't remove this function, in case we want to recompute those tables in the future.
SkColorMatrix_DumpYUVMatrixTables()321 void SkColorMatrix_DumpYUVMatrixTables() {
322 for (int i = 0; i < kLastEnum_SkYUVColorSpace; ++i) {
323 SkYUVColorSpace cs = static_cast<SkYUVColorSpace>(i);
324 float m[20];
325 make_rgb_to_yuv_matrix(m, gCoeff[(unsigned)cs]);
326 dump(m, cs, true);
327 SkM44 m44, im44;
328 colormatrix_to_matrix44(m, &m44);
329 float im[20];
330 #ifdef SK_DEBUG
331 // be sure our coversion between matrix44 and colormatrix is perfect
332 matrix44_to_colormatrix(m44, im);
333 SkASSERT(memcmp(m, im, sizeof(im)) == 0);
334 #endif
335 SkAssertResult(m44.invert(&im44));
336 matrix44_to_colormatrix(im44, im);
337 dump(im, cs, false);
338 }
339 }
340