ffmpeg/libavcodec/imgconvert.c

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/*
* Misc image convertion routines
* Copyright (c) 2001 Gerard Lantau.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "avcodec.h"
/* XXX: totally non optimized */
static void yuv422_to_yuv420p(UINT8 *lum, UINT8 *cb, UINT8 *cr,
UINT8 *src, int width, int height)
{
int x, y;
UINT8 *p = src;
for(y=0;y<height;y+=2) {
for(x=0;x<width;x+=2) {
lum[0] = p[0];
cb[0] = p[1];
lum[1] = p[2];
cr[0] = p[3];
p += 4;
lum += 2;
cb++;
cr++;
}
for(x=0;x<width;x+=2) {
lum[0] = p[0];
lum[1] = p[2];
p += 4;
lum += 2;
}
}
}
#define SCALEBITS 8
#define ONE_HALF (1 << (SCALEBITS - 1))
#define FIX(x) ((int) ((x) * (1L<<SCALEBITS) + 0.5))
static void rgb24_to_yuv420p(UINT8 *lum, UINT8 *cb, UINT8 *cr,
UINT8 *src, int width, int height)
{
int wrap, wrap3, x, y;
int r, g, b, r1, g1, b1;
UINT8 *p;
wrap = width;
wrap3 = width * 3;
p = src;
for(y=0;y<height;y+=2) {
for(x=0;x<width;x+=2) {
r = p[0];
g = p[1];
b = p[2];
r1 = r;
g1 = g;
b1 = b;
lum[0] = (FIX(0.29900) * r + FIX(0.58700) * g +
FIX(0.11400) * b + ONE_HALF) >> SCALEBITS;
r = p[3];
g = p[4];
b = p[5];
r1 += r;
g1 += g;
b1 += b;
lum[1] = (FIX(0.29900) * r + FIX(0.58700) * g +
FIX(0.11400) * b + ONE_HALF) >> SCALEBITS;
p += wrap3;
lum += wrap;
r = p[0];
g = p[1];
b = p[2];
r1 += r;
g1 += g;
b1 += b;
lum[0] = (FIX(0.29900) * r + FIX(0.58700) * g +
FIX(0.11400) * b + ONE_HALF) >> SCALEBITS;
r = p[3];
g = p[4];
b = p[5];
r1 += r;
g1 += g;
b1 += b;
lum[1] = (FIX(0.29900) * r + FIX(0.58700) * g +
FIX(0.11400) * b + ONE_HALF) >> SCALEBITS;
cb[0] = ((- FIX(0.16874) * r1 - FIX(0.33126) * g1 +
FIX(0.50000) * b1 + 4 * ONE_HALF - 1) >> (SCALEBITS + 2)) + 128;
cr[0] = ((FIX(0.50000) * r1 - FIX(0.41869) * g1 -
FIX(0.08131) * b1 + 4 * ONE_HALF - 1) >> (SCALEBITS + 2)) + 128;
cb++;
cr++;
p += -wrap3 + 2 * 3;
lum += -wrap + 2;
}
p += wrap3;
lum += wrap;
}
}
static void bgr24_to_yuv420p(UINT8 *lum, UINT8 *cb, UINT8 *cr,
UINT8 *src, int width, int height)
{
int wrap, wrap3, x, y;
int r, g, b, r1, g1, b1;
UINT8 *p;
wrap = width;
wrap3 = width * 3;
p = src;
for(y=0;y<height;y+=2) {
for(x=0;x<width;x+=2) {
b = p[0];
g = p[1];
r = p[2];
r1 = r;
g1 = g;
b1 = b;
lum[0] = (FIX(0.29900) * r + FIX(0.58700) * g +
FIX(0.11400) * b + ONE_HALF) >> SCALEBITS;
b = p[3];
g = p[4];
r = p[5];
r1 += r;
g1 += g;
b1 += b;
lum[1] = (FIX(0.29900) * r + FIX(0.58700) * g +
FIX(0.11400) * b + ONE_HALF) >> SCALEBITS;
p += wrap3;
lum += wrap;
b = p[0];
g = p[1];
r = p[2];
r1 += r;
g1 += g;
b1 += b;
lum[0] = (FIX(0.29900) * r + FIX(0.58700) * g +
FIX(0.11400) * b + ONE_HALF) >> SCALEBITS;
b = p[3];
g = p[4];
r = p[5];
r1 += r;
g1 += g;
b1 += b;
lum[1] = (FIX(0.29900) * r + FIX(0.58700) * g +
FIX(0.11400) * b + ONE_HALF) >> SCALEBITS;
cb[0] = ((- FIX(0.16874) * r1 - FIX(0.33126) * g1 +
FIX(0.50000) * b1 + 4 * ONE_HALF - 1) >> (SCALEBITS + 2)) + 128;
cr[0] = ((FIX(0.50000) * r1 - FIX(0.41869) * g1 -
FIX(0.08131) * b1 + 4 * ONE_HALF - 1) >> (SCALEBITS + 2)) + 128;
cb++;
cr++;
p += -wrap3 + 2 * 3;
lum += -wrap + 2;
}
p += wrap3;
lum += wrap;
}
}
int img_convert_to_yuv420(UINT8 *img_out, UINT8 *img,
int pix_fmt, int width, int height)
{
UINT8 *pict;
int size, size_out;
UINT8 *picture[3];
pict = img_out;
size = width * height;
size_out = (size * 3) / 2;
picture[0] = pict;
picture[1] = pict + size;
picture[2] = picture[1] + (size / 4);
switch(pix_fmt) {
case PIX_FMT_YUV420P:
memcpy(pict, img, size_out);
break;
case PIX_FMT_YUV422:
yuv422_to_yuv420p(picture[0], picture[1], picture[2],
img, width, height);
break;
case PIX_FMT_RGB24:
rgb24_to_yuv420p(picture[0], picture[1], picture[2],
img, width, height);
break;
case PIX_FMT_BGR24:
bgr24_to_yuv420p(picture[0], picture[1], picture[2],
img, width, height);
break;
}
return size_out;
}