1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
|
/*
* 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 <stdio.h>
#include <stdlib.h>
#define SCALEBITS 8
#define ONE_HALF (1 << (SCALEBITS - 1))
#define FIX(x) ((int) ((x) * (1L << SCALEBITS) + 0.5))
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);
f = fopen(filename, "wb");
fprintf(f, "P5\n%d %d\n%d\n", w, h * 3 / 2, 255);
fwrite(lum_tab, 1, w * h, f);
h2 = h / 2;
w2 = w / 2;
cb = cb_tab;
cr = cr_tab;
for (i = 0; i < h2; i++) {
fwrite(cb, 1, w2, f);
fwrite(cr, 1, w2, f);
cb += w2;
cr += w2;
}
fclose(f);
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;
}
|
