correct pcm audio format handling
[libav.git] / libav / grab.c
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1/*
2 * Linux video grab interface
3 * Copyright (c) 2000,2001 Gerard Lantau.
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18 */
8be1c656 19#include "avformat.h"
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20#include <linux/videodev.h>
21#include <unistd.h>
22#include <fcntl.h>
23#include <sys/ioctl.h>
24#include <sys/mman.h>
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25#include <sys/time.h>
26
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27
28typedef struct {
29 int fd;
30 int frame_format; /* see VIDEO_PALETTE_xxx */
31 int use_mmap;
32 int width, height;
33 float rate;
34 INT64 time_frame;
35} VideoData;
36
37const char *v4l_device = "/dev/video";
38
39/* XXX: move all that to the context */
40
41static struct video_capability video_cap;
42static UINT8 *video_buf;
43static struct video_mbuf gb_buffers;
44static struct video_mmap gb_buf;
5a56c87c 45static struct video_audio audio, audio_saved;
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46static int gb_frame = 0;
47
48static int v4l_init(URLContext *h)
49{
50 VideoData *s = h->priv_data;
51 int width, height;
52 int ret;
53 int video_fd, frame_size;
54
55 width = s->width;
56 height = s->height;
57
58 video_fd = open(v4l_device, O_RDWR);
59 if (video_fd < 0) {
60 perror(v4l_device);
61 return -EIO;
62 }
63
64 if (ioctl(video_fd,VIDIOCGCAP,&video_cap) < 0) {
65 perror("VIDIOCGCAP");
66 goto fail;
67 }
68
69 if (!(video_cap.type & VID_TYPE_CAPTURE)) {
70 fprintf(stderr, "Fatal: grab device does not handle capture\n");
71 goto fail;
72 }
73
74 /* unmute audio */
75 ioctl(video_fd, VIDIOCGAUDIO, &audio);
5a56c87c 76 memcpy(&audio_saved, &audio, sizeof(audio));
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77 audio.flags &= ~VIDEO_AUDIO_MUTE;
78 ioctl(video_fd, VIDIOCSAUDIO, &audio);
79
80 ret = ioctl(video_fd,VIDIOCGMBUF,&gb_buffers);
81 if (ret < 0) {
82 /* try to use read based access */
83 struct video_window win;
84 struct video_picture pict;
85 int val;
86
87 win.x = 0;
88 win.y = 0;
89 win.width = width;
90 win.height = height;
91 win.chromakey = -1;
92 win.flags = 0;
93
94 ioctl(video_fd, VIDIOCSWIN, &win);
95
96 ioctl(video_fd, VIDIOCGPICT, &pict);
97#if 0
98 printf("v4l: colour=%d hue=%d brightness=%d constrast=%d whiteness=%d\n",
99 pict.colour,
100 pict.hue,
101 pict.brightness,
102 pict.contrast,
103 pict.whiteness);
104#endif
105 /* try to choose a suitable video format */
106 pict.palette=VIDEO_PALETTE_YUV420P;
107 ret = ioctl(video_fd, VIDIOCSPICT, &pict);
108 if (ret < 0) {
109 pict.palette=VIDEO_PALETTE_YUV422;
110 ret = ioctl(video_fd, VIDIOCSPICT, &pict);
111 if (ret < 0) {
112 pict.palette=VIDEO_PALETTE_RGB24;
113 ret = ioctl(video_fd, VIDIOCSPICT, &pict);
114 if (ret < 0)
115 goto fail1;
116 }
117 }
118
119 s->frame_format = pict.palette;
120
121 val = 1;
122 ioctl(video_fd, VIDIOCCAPTURE, &val);
123
124 s->time_frame = gettime();
125 s->use_mmap = 0;
126 } else {
127 video_buf = mmap(0,gb_buffers.size,PROT_READ|PROT_WRITE,MAP_SHARED,video_fd,0);
128 if ((unsigned char*)-1 == video_buf) {
129 perror("mmap");
130 goto fail;
131 }
132 gb_frame = 0;
133 s->time_frame = gettime();
134
135 /* start to grab the first frame */
5a56c87c 136 gb_buf.frame = (gb_frame + 1) % gb_buffers.frames;
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137 gb_buf.height = height;
138 gb_buf.width = width;
139 gb_buf.format = VIDEO_PALETTE_YUV420P;
140
141 ret = ioctl(video_fd, VIDIOCMCAPTURE, &gb_buf);
142 if (ret < 0 && errno != EAGAIN) {
143 /* try YUV422 */
144 gb_buf.format = VIDEO_PALETTE_YUV422;
145
146 ret = ioctl(video_fd, VIDIOCMCAPTURE, &gb_buf);
147 if (ret < 0 && errno != EAGAIN) {
148 /* try RGB24 */
149 gb_buf.format = VIDEO_PALETTE_RGB24;
150 ret = ioctl(video_fd, VIDIOCMCAPTURE, &gb_buf);
151 }
152 }
153 if (ret < 0) {
154 if (errno != EAGAIN) {
155 fail1:
156 fprintf(stderr, "Fatal: grab device does not support suitable format\n");
157 } else {
158 fprintf(stderr,"Fatal: grab device does not receive any video signal\n");
159 }
160 goto fail;
161 }
162 s->frame_format = gb_buf.format;
163 s->use_mmap = 1;
164 }
165
166 switch(s->frame_format) {
167 case VIDEO_PALETTE_YUV420P:
168 frame_size = (width * height * 3) / 2;
169 break;
170 case VIDEO_PALETTE_YUV422:
171 frame_size = width * height * 2;
172 break;
173 case VIDEO_PALETTE_RGB24:
174 frame_size = width * height * 3;
175 break;
176 default:
177 goto fail;
178 }
179 s->fd = video_fd;
180 h->packet_size = frame_size;
181 return 0;
182 fail:
183 close(video_fd);
184 return -EIO;
185}
186
187static int v4l_mm_read_picture(URLContext *h, UINT8 *buf)
188{
189 VideoData *s = h->priv_data;
190 UINT8 *ptr;
191
192 gb_buf.frame = gb_frame;
193 if (ioctl(s->fd, VIDIOCMCAPTURE, &gb_buf) < 0) {
194 if (errno == EAGAIN)
195 fprintf(stderr,"Cannot Sync\n");
196 else
197 perror("VIDIOCMCAPTURE");
198 return -EIO;
199 }
5a56c87c 200 gb_frame = (gb_frame + 1) % gb_buffers.frames;
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201
202 while (ioctl(s->fd, VIDIOCSYNC, &gb_frame) < 0 &&
203 (errno == EAGAIN || errno == EINTR));
204
205 ptr = video_buf + gb_buffers.offsets[gb_frame];
206 memcpy(buf, ptr, h->packet_size);
207 return h->packet_size;
208}
209
210/* note: we support only one picture read at a time */
211static int video_read(URLContext *h, UINT8 *buf, int size)
212{
213 VideoData *s = h->priv_data;
214 INT64 curtime;
215
216 if (size != h->packet_size)
217 return -EINVAL;
218
219 /* wait based on the frame rate */
220 s->time_frame += (int)(1000000 / s->rate);
221 do {
222 curtime = gettime();
223 } while (curtime < s->time_frame);
224
225 /* read one frame */
226 if (s->use_mmap) {
227 return v4l_mm_read_picture(h, buf);
228 } else {
229 if (read(s->fd, buf, size) != size)
230 return -EIO;
231 return h->packet_size;
232 }
233}
234
235static int video_get_format(URLContext *h, URLFormat *f)
236{
237 VideoData *s = h->priv_data;
238
239 f->width = s->width;
240 f->height = s->height;
241 f->frame_rate = (int)(s->rate * FRAME_RATE_BASE);
242 strcpy(f->format_name, "rawvideo");
243
244 switch(s->frame_format) {
245 case VIDEO_PALETTE_YUV420P:
246 f->pix_fmt = PIX_FMT_YUV420P;
247 break;
248 case VIDEO_PALETTE_YUV422:
249 f->pix_fmt = PIX_FMT_YUV422;
250 break;
251 case VIDEO_PALETTE_RGB24:
252 f->pix_fmt = PIX_FMT_BGR24; /* NOTE: v4l uses BGR24, not RGB24 ! */
253 break;
254 default:
255 abort();
256 }
257 return 0;
258}
259
260/* URI syntax: 'video:width,height,rate'
261 */
262static int video_open(URLContext *h, const char *uri, int flags)
263{
264 VideoData *s;
265 const char *p;
266 int width, height;
267 int ret;
268 float rate;
269
270 /* extract parameters */
271 p = uri;
272 strstart(p, "video:", &p);
273 width = strtol(p, (char **)&p, 0);
274 if (width <= 0)
275 return -EINVAL;
276 if (*p == ',')
277 p++;
278 height = strtol(p, (char **)&p, 0);
279 if (height <= 0)
280 return -EINVAL;
281 if (*p == ',')
282 p++;
283 rate = strtod(p, (char **)&p);
284 if (rate <= 0)
285 return -EINVAL;
286
287 s = malloc(sizeof(VideoData));
288 if (!s)
289 return -ENOMEM;
290 h->priv_data = s;
291 h->is_streamed = 1;
292 s->width = width;
293 s->height = height;
294 s->rate = rate;
295 ret = v4l_init(h);
296 if (ret)
297 free(s);
298 return ret;
299}
300
301static int video_close(URLContext *h)
302{
303 VideoData *s = h->priv_data;
304
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305 /* restore audio settings */
306 ioctl(s->fd, VIDIOCSAUDIO, &audio_saved);
307
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308 close(s->fd);
309 free(s);
310 return 0;
311}
312
313URLProtocol video_protocol = {
314 "video",
315 video_open,
316 video_read,
317 NULL,
318 NULL, /* seek */
319 video_close,
320 video_get_format,
321};