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Diffstat (limited to 'Documentation/video4linux/v4lgrab.c')
-rw-r--r-- | Documentation/video4linux/v4lgrab.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/Documentation/video4linux/v4lgrab.c b/Documentation/video4linux/v4lgrab.c new file mode 100644 index 000000000000..079b628481cf --- /dev/null +++ b/Documentation/video4linux/v4lgrab.c | |||
@@ -0,0 +1,192 @@ | |||
1 | /* Simple Video4Linux image grabber. */ | ||
2 | /* | ||
3 | * Video4Linux Driver Test/Example Framegrabbing Program | ||
4 | * | ||
5 | * Compile with: | ||
6 | * gcc -s -Wall -Wstrict-prototypes v4lgrab.c -o v4lgrab | ||
7 | * Use as: | ||
8 | * v4lgrab >image.ppm | ||
9 | * | ||
10 | * Copyright (C) 1998-05-03, Phil Blundell <philb@gnu.org> | ||
11 | * Copied from http://www.tazenda.demon.co.uk/phil/vgrabber.c | ||
12 | * with minor modifications (Dave Forrest, drf5n@virginia.edu). | ||
13 | * | ||
14 | */ | ||
15 | |||
16 | #include <unistd.h> | ||
17 | #include <sys/types.h> | ||
18 | #include <sys/stat.h> | ||
19 | #include <fcntl.h> | ||
20 | #include <stdio.h> | ||
21 | #include <sys/ioctl.h> | ||
22 | #include <stdlib.h> | ||
23 | |||
24 | #include <linux/types.h> | ||
25 | #include <linux/videodev.h> | ||
26 | |||
27 | #define FILE "/dev/video0" | ||
28 | |||
29 | /* Stole this from tvset.c */ | ||
30 | |||
31 | #define READ_VIDEO_PIXEL(buf, format, depth, r, g, b) \ | ||
32 | { \ | ||
33 | switch (format) \ | ||
34 | { \ | ||
35 | case VIDEO_PALETTE_GREY: \ | ||
36 | switch (depth) \ | ||
37 | { \ | ||
38 | case 4: \ | ||
39 | case 6: \ | ||
40 | case 8: \ | ||
41 | (r) = (g) = (b) = (*buf++ << 8);\ | ||
42 | break; \ | ||
43 | \ | ||
44 | case 16: \ | ||
45 | (r) = (g) = (b) = \ | ||
46 | *((unsigned short *) buf); \ | ||
47 | buf += 2; \ | ||
48 | break; \ | ||
49 | } \ | ||
50 | break; \ | ||
51 | \ | ||
52 | \ | ||
53 | case VIDEO_PALETTE_RGB565: \ | ||
54 | { \ | ||
55 | unsigned short tmp = *(unsigned short *)buf; \ | ||
56 | (r) = tmp&0xF800; \ | ||
57 | (g) = (tmp<<5)&0xFC00; \ | ||
58 | (b) = (tmp<<11)&0xF800; \ | ||
59 | buf += 2; \ | ||
60 | } \ | ||
61 | break; \ | ||
62 | \ | ||
63 | case VIDEO_PALETTE_RGB555: \ | ||
64 | (r) = (buf[0]&0xF8)<<8; \ | ||
65 | (g) = ((buf[0] << 5 | buf[1] >> 3)&0xF8)<<8; \ | ||
66 | (b) = ((buf[1] << 2 ) & 0xF8)<<8; \ | ||
67 | buf += 2; \ | ||
68 | break; \ | ||
69 | \ | ||
70 | case VIDEO_PALETTE_RGB24: \ | ||
71 | (r) = buf[0] << 8; (g) = buf[1] << 8; \ | ||
72 | (b) = buf[2] << 8; \ | ||
73 | buf += 3; \ | ||
74 | break; \ | ||
75 | \ | ||
76 | default: \ | ||
77 | fprintf(stderr, \ | ||
78 | "Format %d not yet supported\n", \ | ||
79 | format); \ | ||
80 | } \ | ||
81 | } | ||
82 | |||
83 | int get_brightness_adj(unsigned char *image, long size, int *brightness) { | ||
84 | long i, tot = 0; | ||
85 | for (i=0;i<size*3;i++) | ||
86 | tot += image[i]; | ||
87 | *brightness = (128 - tot/(size*3))/3; | ||
88 | return !((tot/(size*3)) >= 126 && (tot/(size*3)) <= 130); | ||
89 | } | ||
90 | |||
91 | int main(int argc, char ** argv) | ||
92 | { | ||
93 | int fd = open(FILE, O_RDONLY), f; | ||
94 | struct video_capability cap; | ||
95 | struct video_window win; | ||
96 | struct video_picture vpic; | ||
97 | |||
98 | unsigned char *buffer, *src; | ||
99 | int bpp = 24, r, g, b; | ||
100 | unsigned int i, src_depth; | ||
101 | |||
102 | if (fd < 0) { | ||
103 | perror(FILE); | ||
104 | exit(1); | ||
105 | } | ||
106 | |||
107 | if (ioctl(fd, VIDIOCGCAP, &cap) < 0) { | ||
108 | perror("VIDIOGCAP"); | ||
109 | fprintf(stderr, "(" FILE " not a video4linux device?)\n"); | ||
110 | close(fd); | ||
111 | exit(1); | ||
112 | } | ||
113 | |||
114 | if (ioctl(fd, VIDIOCGWIN, &win) < 0) { | ||
115 | perror("VIDIOCGWIN"); | ||
116 | close(fd); | ||
117 | exit(1); | ||
118 | } | ||
119 | |||
120 | if (ioctl(fd, VIDIOCGPICT, &vpic) < 0) { | ||
121 | perror("VIDIOCGPICT"); | ||
122 | close(fd); | ||
123 | exit(1); | ||
124 | } | ||
125 | |||
126 | if (cap.type & VID_TYPE_MONOCHROME) { | ||
127 | vpic.depth=8; | ||
128 | vpic.palette=VIDEO_PALETTE_GREY; /* 8bit grey */ | ||
129 | if(ioctl(fd, VIDIOCSPICT, &vpic) < 0) { | ||
130 | vpic.depth=6; | ||
131 | if(ioctl(fd, VIDIOCSPICT, &vpic) < 0) { | ||
132 | vpic.depth=4; | ||
133 | if(ioctl(fd, VIDIOCSPICT, &vpic) < 0) { | ||
134 | fprintf(stderr, "Unable to find a supported capture format.\n"); | ||
135 | close(fd); | ||
136 | exit(1); | ||
137 | } | ||
138 | } | ||
139 | } | ||
140 | } else { | ||
141 | vpic.depth=24; | ||
142 | vpic.palette=VIDEO_PALETTE_RGB24; | ||
143 | |||
144 | if(ioctl(fd, VIDIOCSPICT, &vpic) < 0) { | ||
145 | vpic.palette=VIDEO_PALETTE_RGB565; | ||
146 | vpic.depth=16; | ||
147 | |||
148 | if(ioctl(fd, VIDIOCSPICT, &vpic)==-1) { | ||
149 | vpic.palette=VIDEO_PALETTE_RGB555; | ||
150 | vpic.depth=15; | ||
151 | |||
152 | if(ioctl(fd, VIDIOCSPICT, &vpic)==-1) { | ||
153 | fprintf(stderr, "Unable to find a supported capture format.\n"); | ||
154 | return -1; | ||
155 | } | ||
156 | } | ||
157 | } | ||
158 | } | ||
159 | |||
160 | buffer = malloc(win.width * win.height * bpp); | ||
161 | if (!buffer) { | ||
162 | fprintf(stderr, "Out of memory.\n"); | ||
163 | exit(1); | ||
164 | } | ||
165 | |||
166 | do { | ||
167 | int newbright; | ||
168 | read(fd, buffer, win.width * win.height * bpp); | ||
169 | f = get_brightness_adj(buffer, win.width * win.height, &newbright); | ||
170 | if (f) { | ||
171 | vpic.brightness += (newbright << 8); | ||
172 | if(ioctl(fd, VIDIOCSPICT, &vpic)==-1) { | ||
173 | perror("VIDIOSPICT"); | ||
174 | break; | ||
175 | } | ||
176 | } | ||
177 | } while (f); | ||
178 | |||
179 | fprintf(stdout, "P6\n%d %d 255\n", win.width, win.height); | ||
180 | |||
181 | src = buffer; | ||
182 | |||
183 | for (i = 0; i < win.width * win.height; i++) { | ||
184 | READ_VIDEO_PIXEL(src, vpic.palette, src_depth, r, g, b); | ||
185 | fputc(r>>8, stdout); | ||
186 | fputc(g>>8, stdout); | ||
187 | fputc(b>>8, stdout); | ||
188 | } | ||
189 | |||
190 | close(fd); | ||
191 | return 0; | ||
192 | } | ||