FFmpeg
libavutil
colorspace.h
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/*
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* Colorspace conversion defines
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* Copyright (c) 2001, 2002, 2003 Fabrice Bellard
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/**
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* @file
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* Various defines for YUV<->RGB conversion
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*/
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#ifndef AVUTIL_COLORSPACE_H
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#define AVUTIL_COLORSPACE_H
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#define SCALEBITS 10
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#define ONE_HALF (1 << (SCALEBITS - 1))
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#define FIX(x) ((int) ((x) * (1<<SCALEBITS) + 0.5))
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#define YUV_TO_RGB1_CCIR(cb1, cr1)\
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{\
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cb = (cb1) - 128;\
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cr = (cr1) - 128;\
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r_add = FIX(1.40200*255.0/224.0) * cr + ONE_HALF;\
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g_add = - FIX(0.34414*255.0/224.0) * cb - FIX(0.71414*255.0/224.0) * cr + \
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ONE_HALF;\
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b_add = FIX(1.77200*255.0/224.0) * cb + ONE_HALF;\
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}
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#define YUV_TO_RGB1_CCIR_BT709(cb1, cr1) \
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{ \
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cb = (cb1) - 128; \
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cr = (cr1) - 128; \
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r_add = ONE_HALF + FIX(1.5747 * 255.0 / 224.0) * cr; \
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g_add = ONE_HALF - FIX(0.1873 * 255.0 / 224.0) * cb - \
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FIX(0.4682 * 255.0 / 224.0) * cr; \
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b_add = ONE_HALF + FIX(1.8556 * 255.0 / 224.0) * cb; \
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}
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// To be used for the BT709 variant as well
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#define YUV_TO_RGB2_CCIR(r, g, b, y1)\
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{\
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y = ((y1) - 16) * FIX(255.0/219.0);\
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r = cm[(y + r_add) >> SCALEBITS];\
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g = cm[(y + g_add) >> SCALEBITS];\
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b = cm[(y + b_add) >> SCALEBITS];\
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}
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#define YUV_TO_RGB1(cb1, cr1)\
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{\
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cb = (cb1) - 128;\
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cr = (cr1) - 128;\
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r_add = FIX(1.40200) * cr + ONE_HALF;\
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g_add = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;\
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b_add = FIX(1.77200) * cb + ONE_HALF;\
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}
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#define YUV_TO_RGB2(r, g, b, y1)\
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{\
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y = (y1) << SCALEBITS;\
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r = cm[(y + r_add) >> SCALEBITS];\
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g = cm[(y + g_add) >> SCALEBITS];\
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b = cm[(y + b_add) >> SCALEBITS];\
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}
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#define Y_CCIR_TO_JPEG(y)\
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cm[((y) * FIX(255.0/219.0) + (ONE_HALF - 16 * FIX(255.0/219.0))) >> SCALEBITS]
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#define Y_JPEG_TO_CCIR(y)\
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(((y) * FIX(219.0/255.0) + (ONE_HALF + (16 << SCALEBITS))) >> SCALEBITS)
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#define C_CCIR_TO_JPEG(y)\
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cm[(((y) - 128) * FIX(127.0/112.0) + (ONE_HALF + (128 << SCALEBITS))) >> SCALEBITS]
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/* NOTE: the clamp is really necessary! */
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static
inline
int
C_JPEG_TO_CCIR
(
int
y) {
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y = (((y - 128) *
FIX
(112.0/127.0) + (
ONE_HALF
+ (128 <<
SCALEBITS
))) >>
SCALEBITS
);
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if
(y < 16)
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y = 16;
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return
y;
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}
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#define RGB_TO_Y_CCIR(r, g, b) \
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((FIX(0.29900*219.0/255.0) * (r) + FIX(0.58700*219.0/255.0) * (g) + \
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FIX(0.11400*219.0/255.0) * (b) + (ONE_HALF + (16 << SCALEBITS))) >> SCALEBITS)
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#define RGB_TO_U_CCIR(r1, g1, b1, shift)\
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(((- FIX(0.16874*224.0/255.0) * r1 - FIX(0.33126*224.0/255.0) * g1 + \
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FIX(0.50000*224.0/255.0) * b1 + (ONE_HALF << shift) - 1) >> (SCALEBITS + shift)) + 128)
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#define RGB_TO_V_CCIR(r1, g1, b1, shift)\
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(((FIX(0.50000*224.0/255.0) * r1 - FIX(0.41869*224.0/255.0) * g1 - \
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FIX(0.08131*224.0/255.0) * b1 + (ONE_HALF << shift) - 1) >> (SCALEBITS + shift)) + 128)
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#define RGB_TO_Y_JPEG(r, g, b) \
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(FFMIN((FIX(0.29900) * (r) + FIX(0.58700) * (g) + \
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FIX(0.11400) * (b) + (ONE_HALF)) >> SCALEBITS, 255))
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#define RGB_TO_U_JPEG(r1, g1, b1)\
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(((- FIX(0.16874) * r1 - FIX(0.33126) * g1 + \
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FIX(0.50000) * b1 + (ONE_HALF) - 1) >> (SCALEBITS)) + 128)
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#define RGB_TO_V_JPEG(r1, g1, b1)\
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(((FIX(0.50000) * r1 - FIX(0.41869) * g1 - \
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FIX(0.08131) * b1 + (ONE_HALF) - 1) >> (SCALEBITS)) + 128)
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// Conversion macros for 8-bit RGB to YUV
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// Derived from ITU-R BT.709-6 (06/2015) Item 3.5
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// https://www.itu.int/rec/R-REC-BT.709-6-201506-I/en
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#define RGB_TO_Y_BT709(r, g, b) \
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((FIX(0.21260*219.0/255.0) * (r) + FIX(0.71520*219.0/255.0) * (g) + \
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FIX(0.07220*219.0/255.0) * (b) + (ONE_HALF + (16 << SCALEBITS))) >> SCALEBITS)
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#define RGB_TO_U_BT709(r1, g1, b1, shift)\
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(((- FIX(0.11457*224.0/255.0) * r1 - FIX(0.38543*224.0/255.0) * g1 + \
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FIX(0.50000*224.0/255.0) * b1 + (ONE_HALF << shift) - 1) >> (SCALEBITS + shift)) + 128)
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#define RGB_TO_V_BT709(r1, g1, b1, shift)\
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(((FIX(0.50000*224.0/255.0) * r1 - FIX(0.45415*224.0/255.0) * g1 - \
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FIX(0.04585*224.0/255.0) * b1 + (ONE_HALF << shift) - 1) >> (SCALEBITS + shift)) + 128)
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#define RGB_TO_Y_BT709_FULL(r, g, b) \
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(FFMIN((FIX(0.21260) * (r) + FIX(0.71520) * (g) + \
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FIX(0.07220) * (b) + (ONE_HALF)) >> SCALEBITS, 255))
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#define RGB_TO_U_BT709_FULL(r1, g1, b1)\
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(((- FIX(0.11457) * r1 - FIX(0.38543) * g1 + \
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FIX(0.50000) * b1 + (ONE_HALF) - 1) >> (SCALEBITS)) + 128)
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#define RGB_TO_V_BT709_FULL(r1, g1, b1)\
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(((FIX(0.50000) * r1 - FIX(0.45415) * g1 - \
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FIX(0.04585) * b1 + (ONE_HALF) - 1) >> (SCALEBITS)) + 128)
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#endif
/* AVUTIL_COLORSPACE_H */
FIX
#define FIX(x)
Definition:
colorspace.h:32
SCALEBITS
#define SCALEBITS
Definition:
colorspace.h:30
ONE_HALF
#define ONE_HALF
Definition:
colorspace.h:31
C_JPEG_TO_CCIR
static int C_JPEG_TO_CCIR(int y)
Definition:
colorspace.h:90
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