mirror of https://git.ffmpeg.org/ffmpeg.git
154 lines
4.5 KiB
C
154 lines
4.5 KiB
C
/*
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* This file is part of Libav.
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*
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* Libav 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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* Libav 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 Libav; 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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#include <errno.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#define SCALEBITS 8
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#define ONE_HALF (1 << (SCALEBITS - 1))
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#define FIX(x) ((int) ((x) * (1L << SCALEBITS) + 0.5))
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#define err_if(expr) do { \
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if (expr) { \
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fprintf(stderr, "%s\n", strerror(errno)); \
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exit(1); \
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} \
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} while (0)
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static void rgb24_to_yuv420p(unsigned char *lum, unsigned char *cb,
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unsigned char *cr, unsigned char *src,
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int width, int height)
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{
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int wrap, wrap3, x, y;
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int r, g, b, r1, g1, b1;
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unsigned char *p;
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wrap = width;
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wrap3 = width * 3;
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p = src;
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for (y = 0; y < height; y += 2) {
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for (x = 0; x < width; x += 2) {
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r = p[0];
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g = p[1];
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b = p[2];
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r1 = r;
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g1 = g;
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b1 = b;
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lum[0] = (FIX(0.29900) * r + FIX(0.58700) * g +
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FIX(0.11400) * b + ONE_HALF) >> SCALEBITS;
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r = p[3];
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g = p[4];
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b = p[5];
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r1 += r;
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g1 += g;
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b1 += b;
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lum[1] = (FIX(0.29900) * r + FIX(0.58700) * g +
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FIX(0.11400) * b + ONE_HALF) >> SCALEBITS;
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p += wrap3;
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lum += wrap;
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r = p[0];
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g = p[1];
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b = p[2];
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r1 += r;
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g1 += g;
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b1 += b;
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lum[0] = (FIX(0.29900) * r + FIX(0.58700) * g +
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FIX(0.11400) * b + ONE_HALF) >> SCALEBITS;
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r = p[3];
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g = p[4];
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b = p[5];
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r1 += r;
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g1 += g;
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b1 += b;
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lum[1] = (FIX(0.29900) * r + FIX(0.58700) * g +
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FIX(0.11400) * b + ONE_HALF) >> SCALEBITS;
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cb[0] = ((- FIX(0.16874) * r1 - FIX(0.33126) * g1 +
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FIX(0.50000) * b1 + 4 * ONE_HALF - 1) >> (SCALEBITS + 2)) + 128;
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cr[0] = ((FIX(0.50000) * r1 - FIX(0.41869) * g1 -
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FIX(0.08131) * b1 + 4 * ONE_HALF - 1) >> (SCALEBITS + 2)) + 128;
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cb++;
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cr++;
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p += -wrap3 + 2 * 3;
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lum += -wrap + 2;
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}
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p += wrap3;
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lum += wrap;
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}
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}
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/* cif format */
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#define DEFAULT_WIDTH 352
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#define DEFAULT_HEIGHT 288
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#define DEFAULT_NB_PICT 50
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static void pgmyuv_save(const char *filename, int w, int h,
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unsigned char *rgb_tab)
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{
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FILE *f;
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int i, h2, w2;
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unsigned char *cb, *cr;
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unsigned char *lum_tab, *cb_tab, *cr_tab;
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lum_tab = malloc(w * h);
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cb_tab = malloc(w * h / 4);
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cr_tab = malloc(w * h / 4);
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rgb24_to_yuv420p(lum_tab, cb_tab, cr_tab, rgb_tab, w, h);
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f = fopen(filename, "wb");
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fprintf(f, "P5\n%d %d\n%d\n", w, h * 3 / 2, 255);
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err_if(fwrite(lum_tab, 1, w * h, f) != w * h);
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h2 = h / 2;
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w2 = w / 2;
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cb = cb_tab;
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cr = cr_tab;
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for (i = 0; i < h2; i++) {
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err_if(fwrite(cb, 1, w2, f) != w2);
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err_if(fwrite(cr, 1, w2, f) != w2);
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cb += w2;
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cr += w2;
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}
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fclose(f);
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free(lum_tab);
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free(cb_tab);
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free(cr_tab);
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}
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static unsigned char *rgb_tab;
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static int width, height, wrap;
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static void put_pixel(int x, int y, int r, int g, int b)
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{
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unsigned char *p;
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if (x < 0 || x >= width ||
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y < 0 || y >= height)
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return;
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p = rgb_tab + y * wrap + x * 3;
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p[0] = r;
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p[1] = g;
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p[2] = b;
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}
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