1 /*
2 * Colorspace conversion defines
3 * Copyright (c) 2001, 2002, 2003 Fabrice Bellard
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 /**
23 * @file
24 * Various defines for YUV<->RGB conversion
25 */
26
27 #ifndef AVUTIL_COLORSPACE_H
28 #define AVUTIL_COLORSPACE_H
29
30 #define SCALEBITS 10
31 #define ONE_HALF (1 << (SCALEBITS - 1))
32 #define FIX(x) ((int) ((x) * (1<<SCALEBITS) + 0.5))
33
34 #define YUV_TO_RGB1_CCIR(cb1, cr1)\
35 {\
36 cb = (cb1) - 128;\
37 cr = (cr1) - 128;\
38 r_add = FIX(1.40200*255.0/224.0) * cr + ONE_HALF;\
39 g_add = - FIX(0.34414*255.0/224.0) * cb - FIX(0.71414*255.0/224.0) * cr + \
40 ONE_HALF;\
41 b_add = FIX(1.77200*255.0/224.0) * cb + ONE_HALF;\
42 }
43
44 #define YUV_TO_RGB1_CCIR_BT709(cb1, cr1) \
45 { \
46 cb = (cb1) - 128; \
47 cr = (cr1) - 128; \
48 r_add = ONE_HALF + FIX(1.5747 * 255.0 / 224.0) * cr; \
49 g_add = ONE_HALF - FIX(0.1873 * 255.0 / 224.0) * cb - \
50 FIX(0.4682 * 255.0 / 224.0) * cr; \
51 b_add = ONE_HALF + FIX(1.8556 * 255.0 / 224.0) * cb; \
52 }
53
54 // To be used for the BT709 variant as well
55 #define YUV_TO_RGB2_CCIR(r, g, b, y1)\
56 {\
57 y = ((y1) - 16) * FIX(255.0/219.0);\
58 r = cm[(y + r_add) >> SCALEBITS];\
59 g = cm[(y + g_add) >> SCALEBITS];\
60 b = cm[(y + b_add) >> SCALEBITS];\
61 }
62
63 #define YUV_TO_RGB1(cb1, cr1)\
64 {\
65 cb = (cb1) - 128;\
66 cr = (cr1) - 128;\
67 r_add = FIX(1.40200) * cr + ONE_HALF;\
68 g_add = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;\
69 b_add = FIX(1.77200) * cb + ONE_HALF;\
70 }
71
72 #define YUV_TO_RGB2(r, g, b, y1)\
73 {\
74 y = (y1) << SCALEBITS;\
75 r = cm[(y + r_add) >> SCALEBITS];\
76 g = cm[(y + g_add) >> SCALEBITS];\
77 b = cm[(y + b_add) >> SCALEBITS];\
78 }
79
80 #define Y_CCIR_TO_JPEG(y)\
81 cm[((y) * FIX(255.0/219.0) + (ONE_HALF - 16 * FIX(255.0/219.0))) >> SCALEBITS]
82
83 #define Y_JPEG_TO_CCIR(y)\
84 (((y) * FIX(219.0/255.0) + (ONE_HALF + (16 << SCALEBITS))) >> SCALEBITS)
85
86 #define C_CCIR_TO_JPEG(y)\
87 cm[(((y) - 128) * FIX(127.0/112.0) + (ONE_HALF + (128 << SCALEBITS))) >> SCALEBITS]
88
89 /* NOTE: the clamp is really necessary! */
C_JPEG_TO_CCIR(int y)90 static inline int C_JPEG_TO_CCIR(int y) {
91 y = (((y - 128) * FIX(112.0/127.0) + (ONE_HALF + (128 << SCALEBITS))) >> SCALEBITS);
92 if (y < 16)
93 y = 16;
94 return y;
95 }
96
97
98 #define RGB_TO_Y_CCIR(r, g, b) \
99 ((FIX(0.29900*219.0/255.0) * (r) + FIX(0.58700*219.0/255.0) * (g) + \
100 FIX(0.11400*219.0/255.0) * (b) + (ONE_HALF + (16 << SCALEBITS))) >> SCALEBITS)
101
102 #define RGB_TO_U_CCIR(r1, g1, b1, shift)\
103 (((- FIX(0.16874*224.0/255.0) * r1 - FIX(0.33126*224.0/255.0) * g1 + \
104 FIX(0.50000*224.0/255.0) * b1 + (ONE_HALF << shift) - 1) >> (SCALEBITS + shift)) + 128)
105
106 #define RGB_TO_V_CCIR(r1, g1, b1, shift)\
107 (((FIX(0.50000*224.0/255.0) * r1 - FIX(0.41869*224.0/255.0) * g1 - \
108 FIX(0.08131*224.0/255.0) * b1 + (ONE_HALF << shift) - 1) >> (SCALEBITS + shift)) + 128)
109
110 #define RGB_TO_Y_JPEG(r, g, b) \
111 (FFMIN((FIX(0.29900) * (r) + FIX(0.58700) * (g) + \
112 FIX(0.11400) * (b) + (ONE_HALF)) >> SCALEBITS, 255))
113
114 #define RGB_TO_U_JPEG(r1, g1, b1)\
115 (((- FIX(0.16874) * r1 - FIX(0.33126) * g1 + \
116 FIX(0.50000) * b1 + (ONE_HALF) - 1) >> (SCALEBITS)) + 128)
117
118 #define RGB_TO_V_JPEG(r1, g1, b1)\
119 (((FIX(0.50000) * r1 - FIX(0.41869) * g1 - \
120 FIX(0.08131) * b1 + (ONE_HALF) - 1) >> (SCALEBITS)) + 128)
121
122 // Conversion macros for 8-bit RGB to YUV
123 // Derived from ITU-R BT.709-6 (06/2015) Item 3.5
124 // https://www.itu.int/rec/R-REC-BT.709-6-201506-I/en
125
126 #define RGB_TO_Y_BT709(r, g, b) \
127 ((FIX(0.21260*219.0/255.0) * (r) + FIX(0.71520*219.0/255.0) * (g) + \
128 FIX(0.07220*219.0/255.0) * (b) + (ONE_HALF + (16 << SCALEBITS))) >> SCALEBITS)
129
130 #define RGB_TO_U_BT709(r1, g1, b1, shift)\
131 (((- FIX(0.11457*224.0/255.0) * r1 - FIX(0.38543*224.0/255.0) * g1 + \
132 FIX(0.50000*224.0/255.0) * b1 + (ONE_HALF << shift) - 1) >> (SCALEBITS + shift)) + 128)
133
134 #define RGB_TO_V_BT709(r1, g1, b1, shift)\
135 (((FIX(0.50000*224.0/255.0) * r1 - FIX(0.45415*224.0/255.0) * g1 - \
136 FIX(0.04585*224.0/255.0) * b1 + (ONE_HALF << shift) - 1) >> (SCALEBITS + shift)) + 128)
137
138 #define RGB_TO_Y_BT709_FULL(r, g, b) \
139 (FFMIN((FIX(0.21260) * (r) + FIX(0.71520) * (g) + \
140 FIX(0.07220) * (b) + (ONE_HALF)) >> SCALEBITS, 255))
141
142 #define RGB_TO_U_BT709_FULL(r1, g1, b1)\
143 (((- FIX(0.11457) * r1 - FIX(0.38543) * g1 + \
144 FIX(0.50000) * b1 + (ONE_HALF) - 1) >> (SCALEBITS)) + 128)
145
146 #define RGB_TO_V_BT709_FULL(r1, g1, b1)\
147 (((FIX(0.50000) * r1 - FIX(0.45415) * g1 - \
148 FIX(0.04585) * b1 + (ONE_HALF) - 1) >> (SCALEBITS)) + 128)
149
150 #endif /* AVUTIL_COLORSPACE_H */
151