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utils.c
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1 /*
2  * copyright (c) Sebastien Bechet <s.bechet@av7.net>
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include <errno.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <string.h>
25 
26 #define SCALEBITS 8
27 #define ONE_HALF (1 << (SCALEBITS - 1))
28 #define FIX(x) ((int) ((x) * (1 << SCALEBITS) + 0.5))
29 
30 #define err_if(expr) do { \
31  if (expr) { \
32  fprintf(stderr, "%s\n", strerror(errno)); \
33  exit(1); \
34  } \
35 } while (0)
36 
37 static void rgb24_to_yuv420p(unsigned char *lum, unsigned char *cb,
38  unsigned char *cr, const unsigned char *src,
39  int width, int height)
40 {
41  int wrap, wrap3, x, y;
42  int r, g, b, r1, g1, b1;
43  const unsigned char *p;
44 
45  wrap = width;
46  wrap3 = width * 3;
47  p = src;
48  for (y = 0; y < height; y += 2) {
49  for (x = 0; x < width; x += 2) {
50  r = p[0];
51  g = p[1];
52  b = p[2];
53  r1 = r;
54  g1 = g;
55  b1 = b;
56  lum[0] = (FIX(0.29900) * r + FIX(0.58700) * g +
57  FIX(0.11400) * b + ONE_HALF) >> SCALEBITS;
58  r = p[3];
59  g = p[4];
60  b = p[5];
61  r1 += r;
62  g1 += g;
63  b1 += b;
64  lum[1] = (FIX(0.29900) * r + FIX(0.58700) * g +
65  FIX(0.11400) * b + ONE_HALF) >> SCALEBITS;
66  p += wrap3;
67  lum += wrap;
68 
69  r = p[0];
70  g = p[1];
71  b = p[2];
72  r1 += r;
73  g1 += g;
74  b1 += b;
75  lum[0] = (FIX(0.29900) * r + FIX(0.58700) * g +
76  FIX(0.11400) * b + ONE_HALF) >> SCALEBITS;
77  r = p[3];
78  g = p[4];
79  b = p[5];
80  r1 += r;
81  g1 += g;
82  b1 += b;
83  lum[1] = (FIX(0.29900) * r + FIX(0.58700) * g +
84  FIX(0.11400) * b + ONE_HALF) >> SCALEBITS;
85 
86  cb[0] = ((- FIX(0.16874) * r1 - FIX(0.33126) * g1 +
87  FIX(0.50000) * b1 + 4 * ONE_HALF - 1) >> (SCALEBITS + 2)) + 128;
88  cr[0] = ((FIX(0.50000) * r1 - FIX(0.41869) * g1 -
89  FIX(0.08131) * b1 + 4 * ONE_HALF - 1) >> (SCALEBITS + 2)) + 128;
90 
91  cb++;
92  cr++;
93  p += -wrap3 + 2 * 3;
94  lum += -wrap + 2;
95  }
96  p += wrap3;
97  lum += wrap;
98  }
99 }
100 
101 /* cif format */
102 #define DEFAULT_WIDTH 352
103 #define DEFAULT_HEIGHT 288
104 #define DEFAULT_NB_PICT 50
105 
106 static void pgmyuv_save(const char *filename, int w, int h,
107  const unsigned char *rgb_tab)
108 {
109  FILE *f;
110  int i, h2, w2;
111  unsigned char *cb, *cr;
112  unsigned char *lum_tab, *cb_tab, *cr_tab;
113 
114  lum_tab = malloc(w * h);
115  cb_tab = malloc(w * h / 4);
116  cr_tab = malloc(w * h / 4);
117 
118  rgb24_to_yuv420p(lum_tab, cb_tab, cr_tab, rgb_tab, w, h);
119 
120  if (filename) {
121  f = fopen(filename, "wb");
122  fprintf(f, "P5\n%d %d\n%d\n", w, h * 3 / 2, 255);
123  } else {
124  f = stdout;
125  }
126 
127  err_if(fwrite(lum_tab, 1, w * h, f) != w * h);
128  h2 = h / 2;
129  w2 = w / 2;
130  cb = cb_tab;
131  cr = cr_tab;
132 
133  if (filename) {
134  for (i = 0; i < h2; i++) {
135  err_if(fwrite(cb, 1, w2, f) != w2);
136  err_if(fwrite(cr, 1, w2, f) != w2);
137  cb += w2;
138  cr += w2;
139  }
140  fclose(f);
141  } else {
142  for (i = 0; i < h2; i++) {
143  err_if(fwrite(cb, 1, w2, f) != w2);
144  cb += w2;
145  }
146  for (i = 0; i < h2; i++) {
147  err_if(fwrite(cr, 1, w2, f) != w2);
148  cr += w2;
149  }
150  }
151 
152  free(lum_tab);
153  free(cb_tab);
154  free(cr_tab);
155 }
156 
157 static unsigned char *rgb_tab;
158 static int width, height, wrap;
159 
160 static void put_pixel(int x, int y, int r, int g, int b)
161 {
162  unsigned char *p;
163 
164  if (x < 0 || x >= width ||
165  y < 0 || y >= height)
166  return;
167 
168  p = rgb_tab + y * wrap + x * 3;
169  p[0] = r;
170  p[1] = g;
171  p[2] = b;
172 }
#define FIX(x)
Definition: utils.c:28
const char * g
Definition: vf_curves.c:112
const char * b
Definition: vf_curves.c:113
static void pgmyuv_save(const char *filename, int w, int h, const unsigned char *rgb_tab)
Definition: utils.c:106
#define src
Definition: vp8dsp.c:254
static void put_pixel(int x, int y, int r, int g, int b)
Definition: utils.c:160
static double cb(void *priv, double x, double y)
Definition: vf_geq.c:106
static unsigned char * rgb_tab
Definition: utils.c:157
#define err_if(expr)
Definition: utils.c:30
const char * r
Definition: vf_curves.c:111
static double lum(void *priv, double x, double y, int plane)
Definition: vf_fftfilt.c:74
static int wrap
Definition: utils.c:158
static int width
Definition: utils.c:158
#define ONE_HALF
Definition: utils.c:27
static void rgb24_to_yuv420p(unsigned char *lum, unsigned char *cb, unsigned char *cr, const unsigned char *src, int width, int height)
Definition: utils.c:37
#define SCALEBITS
Definition: utils.c:26
static int height
Definition: utils.c:158
static double cr(void *priv, double x, double y)
Definition: vf_geq.c:107