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/*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define SCALEBITS 8
#define ONE_HALF (1 << (SCALEBITS - 1))
#define FIX(x) ((int) ((x) * (1L << SCALEBITS) + 0.5))
#define err_if(expr) do { \
if (expr) { \
fprintf(stderr, "%s\n", strerror(errno)); \
exit(1); \
} \
} while (0)
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static void rgb24_to_yuv420p(unsigned char *lum, unsigned char *cb,
unsigned char *cr, unsigned char *src,
int width, int height)
{
int wrap, wrap3, x, y;
int r, g, b, r1, g1, b1;
unsigned char *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;
}
}
/* cif format */
#define DEFAULT_WIDTH 352
#define DEFAULT_HEIGHT 288
#define DEFAULT_NB_PICT 50
static void pgmyuv_save(const char *filename, int w, int h,
unsigned char *rgb_tab)
{
FILE *f;
int i, h2, w2;
unsigned char *cb, *cr;
unsigned char *lum_tab, *cb_tab, *cr_tab;
lum_tab = malloc(w * h);
cb_tab = malloc(w * h / 4);
cr_tab = malloc(w * h / 4);
rgb24_to_yuv420p(lum_tab, cb_tab, cr_tab, rgb_tab, w, h);
if (filename) {
f = fopen(filename, "wb");
fprintf(f, "P5\n%d %d\n%d\n", w, h * 3 / 2, 255);
} else {
f = stdout;
}
err_if(fwrite(lum_tab, 1, w * h, f) != w * h);
h2 = h / 2;
w2 = w / 2;
cb = cb_tab;
cr = cr_tab;
if (filename) {
for (i = 0; i < h2; i++) {
err_if(fwrite(cb, 1, w2, f) != w2);
err_if(fwrite(cr, 1, w2, f) != w2);
cb += w2;
cr += w2;
}
fclose(f);
} else {
for (i = 0; i < h2; i++) {
err_if(fwrite(cb, 1, w2, f) != w2);
cb += w2;
}
for (i = 0; i < h2; i++) {
err_if(fwrite(cr, 1, w2, f) != w2);
cr += w2;
}
}
free(lum_tab);
free(cb_tab);
free(cr_tab);
}
static unsigned char *rgb_tab;
static int width, height, wrap;
static void put_pixel(int x, int y, int r, int g, int b)
{
unsigned char *p;
if (x < 0 || x >= width ||
y < 0 || y >= height)
return;
p = rgb_tab + y * wrap + x * 3;
p[0] = r;
p[1] = g;
p[2] = b;
}