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
rgb24_to_yuv420p(unsigned char * lum,unsigned char * cb,unsigned char * cr,const unsigned char * src,int width,int height)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
pgmyuv_save(const char * filename,int w,int h,const unsigned char * rgb_tab)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
put_pixel(int x,int y,int r,int g,int b)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 }
173