Statistics
| Branch: | Revision:

ffmpeg / libavdevice / v4l.c @ df2a3f27

History | View | Annotate | Download (10.8 KB)

1
/*
2
 * Linux video grab interface
3
 * Copyright (c) 2000,2001 Fabrice Bellard.
4
 *
5
 * This file is part of FFmpeg.
6
 *
7
 * FFmpeg is free software; you can redistribute it and/or
8
 * modify it under the terms of the GNU Lesser General Public
9
 * License as published by the Free Software Foundation; either
10
 * version 2.1 of the License, or (at your option) any later version.
11
 *
12
 * FFmpeg is distributed in the hope that it will be useful,
13
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15
 * Lesser General Public License for more details.
16
 *
17
 * You should have received a copy of the GNU Lesser General Public
18
 * License along with FFmpeg; if not, write to the Free Software
19
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20
 */
21

    
22
#undef __STRICT_ANSI__ //workaround due to broken kernel headers
23
#include "config.h"
24
#include "libavutil/rational.h"
25
#include "libavformat/avformat.h"
26
#include "libavcodec/dsputil.h"
27
#include <unistd.h>
28
#include <fcntl.h>
29
#include <sys/ioctl.h>
30
#include <sys/mman.h>
31
#include <sys/time.h>
32
#define _LINUX_TIME_H 1
33
#include <linux/videodev.h>
34
#include <time.h>
35
#include <strings.h>
36

    
37
typedef struct {
38
    int fd;
39
    int frame_format; /* see VIDEO_PALETTE_xxx */
40
    int use_mmap;
41
    AVRational time_base;
42
    int64_t time_frame;
43
    int frame_size;
44
    struct video_capability video_cap;
45
    struct video_audio audio_saved;
46
    struct video_window video_win;
47
    uint8_t *video_buf;
48
    struct video_mbuf gb_buffers;
49
    struct video_mmap gb_buf;
50
    int gb_frame;
51
} VideoData;
52

    
53
static const struct {
54
    int palette;
55
    int depth;
56
    enum PixelFormat pix_fmt;
57
} video_formats [] = {
58
    {.palette = VIDEO_PALETTE_YUV420P, .depth = 12, .pix_fmt = PIX_FMT_YUV420P },
59
    {.palette = VIDEO_PALETTE_YUV422,  .depth = 16, .pix_fmt = PIX_FMT_YUYV422 },
60
    {.palette = VIDEO_PALETTE_UYVY,    .depth = 16, .pix_fmt = PIX_FMT_UYVY422 },
61
    {.palette = VIDEO_PALETTE_YUYV,    .depth = 16, .pix_fmt = PIX_FMT_YUYV422 },
62
    /* NOTE: v4l uses BGR24, not RGB24 */
63
    {.palette = VIDEO_PALETTE_RGB24,   .depth = 24, .pix_fmt = PIX_FMT_BGR24   },
64
    {.palette = VIDEO_PALETTE_RGB565,  .depth = 16, .pix_fmt = PIX_FMT_BGR565  },
65
    {.palette = VIDEO_PALETTE_GREY,    .depth = 8,  .pix_fmt = PIX_FMT_GRAY8   },
66
};
67

    
68

    
69
static int grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
70
{
71
    VideoData *s = s1->priv_data;
72
    AVStream *st;
73
    int video_fd;
74
    int desired_palette, desired_depth;
75
    struct video_tuner tuner;
76
    struct video_audio audio;
77
    struct video_picture pict;
78
    int j;
79
    int vformat_num = FF_ARRAY_ELEMS(video_formats);
80

    
81
    if (ap->time_base.den <= 0) {
82
        av_log(s1, AV_LOG_ERROR, "Wrong time base (%d)\n", ap->time_base.den);
83
        return -1;
84
    }
85
    s->time_base = ap->time_base;
86

    
87
    if((unsigned)ap->width > 32767 || (unsigned)ap->height > 32767) {
88
        av_log(s1, AV_LOG_ERROR, "Capture size is out of range: %dx%d\n",
89
            ap->width, ap->height);
90
        return -1;
91
    }
92
    s->video_win.width = ap->width;
93
    s->video_win.height = ap->height;
94

    
95
    st = av_new_stream(s1, 0);
96
    if (!st)
97
        return AVERROR(ENOMEM);
98
    av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
99

    
100
    video_fd = open(s1->filename, O_RDWR);
101
    if (video_fd < 0) {
102
        av_log(s1, AV_LOG_ERROR, "%s: %s\n", s1->filename, strerror(errno));
103
        goto fail;
104
    }
105

    
106
    if (ioctl(video_fd, VIDIOCGCAP, &s->video_cap) < 0) {
107
        av_log(s1, AV_LOG_ERROR, "VIDIOCGCAP: %s\n", strerror(errno));
108
        goto fail;
109
    }
110

    
111
    if (!(s->video_cap.type & VID_TYPE_CAPTURE)) {
112
        av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not handle capture\n");
113
        goto fail;
114
    }
115

    
116
    /* no values set, autodetect them */
117
    if (s->video_win.width <= 0 || s->video_win.height <= 0) {
118
        if (ioctl(video_fd, VIDIOCGWIN, &s->video_win, sizeof(s->video_win)) < 0) {
119
            av_log(s1, AV_LOG_ERROR, "VIDIOCGWIN: %s\n", strerror(errno));
120
            goto fail;
121
        }
122
    }
123

    
124
    desired_palette = -1;
125
    desired_depth = -1;
126
    for (j = 0; j < vformat_num; j++) {
127
        if (ap->pix_fmt == video_formats[j].pix_fmt) {
128
            desired_palette = video_formats[j].palette;
129
            desired_depth = video_formats[j].depth;
130
            break;
131
        }
132
    }
133

    
134
    /* set tv standard */
135
    if (ap->standard && !ioctl(video_fd, VIDIOCGTUNER, &tuner)) {
136
        if (!strcasecmp(ap->standard, "pal"))
137
            tuner.mode = VIDEO_MODE_PAL;
138
        else if (!strcasecmp(ap->standard, "secam"))
139
            tuner.mode = VIDEO_MODE_SECAM;
140
        else
141
            tuner.mode = VIDEO_MODE_NTSC;
142
        ioctl(video_fd, VIDIOCSTUNER, &tuner);
143
    }
144

    
145
    /* unmute audio */
146
    audio.audio = 0;
147
    ioctl(video_fd, VIDIOCGAUDIO, &audio);
148
    memcpy(&s->audio_saved, &audio, sizeof(audio));
149
    audio.flags &= ~VIDEO_AUDIO_MUTE;
150
    ioctl(video_fd, VIDIOCSAUDIO, &audio);
151

    
152
    ioctl(video_fd, VIDIOCGPICT, &pict);
153
#if 0
154
    printf("v4l: colour=%d hue=%d brightness=%d constrast=%d whiteness=%d\n",
155
           pict.colour,
156
           pict.hue,
157
           pict.brightness,
158
           pict.contrast,
159
           pict.whiteness);
160
#endif
161
    /* try to choose a suitable video format */
162
    pict.palette = desired_palette;
163
    pict.depth= desired_depth;
164
    if (desired_palette == -1 || ioctl(video_fd, VIDIOCSPICT, &pict) < 0) {
165
        for (j = 0; j < vformat_num; j++) {
166
            pict.palette = video_formats[j].palette;
167
            pict.depth = video_formats[j].depth;
168
            if (-1 != ioctl(video_fd, VIDIOCSPICT, &pict))
169
                break;
170
        }
171
        if (j >= vformat_num)
172
            goto fail1;
173
    }
174

    
175
    if (ioctl(video_fd, VIDIOCGMBUF, &s->gb_buffers) < 0) {
176
        /* try to use read based access */
177
        int val;
178

    
179
        s->video_win.x = 0;
180
        s->video_win.y = 0;
181
        s->video_win.chromakey = -1;
182
        s->video_win.flags = 0;
183

    
184
        ioctl(video_fd, VIDIOCSWIN, s->video_win);
185

    
186
        s->frame_format = pict.palette;
187

    
188
        val = 1;
189
        if (ioctl(video_fd, VIDIOCCAPTURE, &val) < 0) {
190
            av_log(s1, AV_LOG_ERROR, "VIDIOCCAPTURE: %s\n", strerror(errno));
191
            goto fail;
192
        }
193

    
194
        s->time_frame = av_gettime() * s->time_base.den / s->time_base.num;
195
        s->use_mmap = 0;
196
    } else {
197
        s->video_buf = mmap(0, s->gb_buffers.size, PROT_READ|PROT_WRITE, MAP_SHARED, video_fd, 0);
198
        if ((unsigned char*)-1 == s->video_buf) {
199
            s->video_buf = mmap(0, s->gb_buffers.size, PROT_READ|PROT_WRITE, MAP_PRIVATE, video_fd, 0);
200
            if ((unsigned char*)-1 == s->video_buf) {
201
                av_log(s1, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
202
                goto fail;
203
            }
204
        }
205
        s->gb_frame = 0;
206
        s->time_frame = av_gettime() * s->time_base.den / s->time_base.num;
207

    
208
        /* start to grab the first frame */
209
        s->gb_buf.frame = s->gb_frame % s->gb_buffers.frames;
210
        s->gb_buf.height = s->video_win.height;
211
        s->gb_buf.width = s->video_win.width;
212
        s->gb_buf.format = pict.palette;
213

    
214
        if (ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) {
215
            if (errno != EAGAIN) {
216
            fail1:
217
                av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not support suitable format\n");
218
            } else {
219
                av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not receive any video signal\n");
220
            }
221
            goto fail;
222
        }
223
        for (j = 1; j < s->gb_buffers.frames; j++) {
224
          s->gb_buf.frame = j;
225
          ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf);
226
        }
227
        s->frame_format = s->gb_buf.format;
228
        s->use_mmap = 1;
229
    }
230

    
231
    for (j = 0; j < vformat_num; j++) {
232
        if (s->frame_format == video_formats[j].palette) {
233
            s->frame_size = s->video_win.width * s->video_win.height * video_formats[j].depth / 8;
234
            st->codec->pix_fmt = video_formats[j].pix_fmt;
235
            break;
236
        }
237
    }
238

    
239
    if (j >= vformat_num)
240
        goto fail;
241

    
242
    s->fd = video_fd;
243

    
244
    st->codec->codec_type = CODEC_TYPE_VIDEO;
245
    st->codec->codec_id = CODEC_ID_RAWVIDEO;
246
    st->codec->width = s->video_win.width;
247
    st->codec->height = s->video_win.height;
248
    st->codec->time_base = s->time_base;
249
    st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;
250

    
251
    return 0;
252
 fail:
253
    if (video_fd >= 0)
254
        close(video_fd);
255
    return AVERROR(EIO);
256
}
257

    
258
static int v4l_mm_read_picture(VideoData *s, uint8_t *buf)
259
{
260
    uint8_t *ptr;
261

    
262
    while (ioctl(s->fd, VIDIOCSYNC, &s->gb_frame) < 0 &&
263
           (errno == EAGAIN || errno == EINTR));
264

    
265
    ptr = s->video_buf + s->gb_buffers.offsets[s->gb_frame];
266
    memcpy(buf, ptr, s->frame_size);
267

    
268
    /* Setup to capture the next frame */
269
    s->gb_buf.frame = s->gb_frame;
270
    if (ioctl(s->fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) {
271
        if (errno == EAGAIN)
272
            av_log(NULL, AV_LOG_ERROR, "Cannot Sync\n");
273
        else
274
            av_log(NULL, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno));
275
        return AVERROR(EIO);
276
    }
277

    
278
    /* This is now the grabbing frame */
279
    s->gb_frame = (s->gb_frame + 1) % s->gb_buffers.frames;
280

    
281
    return s->frame_size;
282
}
283

    
284
static int grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
285
{
286
    VideoData *s = s1->priv_data;
287
    int64_t curtime, delay;
288
    struct timespec ts;
289

    
290
    /* Calculate the time of the next frame */
291
    s->time_frame += INT64_C(1000000);
292

    
293
    /* wait based on the frame rate */
294
    for(;;) {
295
        curtime = av_gettime();
296
        delay = s->time_frame * s->time_base.num / s->time_base.den - curtime;
297
        if (delay <= 0) {
298
            if (delay < INT64_C(-1000000) * s->time_base.num / s->time_base.den) {
299
                /* printf("grabbing is %d frames late (dropping)\n", (int) -(delay / 16666)); */
300
                s->time_frame += INT64_C(1000000);
301
            }
302
            break;
303
        }
304
        ts.tv_sec = delay / 1000000;
305
        ts.tv_nsec = (delay % 1000000) * 1000;
306
        nanosleep(&ts, NULL);
307
    }
308

    
309
    if (av_new_packet(pkt, s->frame_size) < 0)
310
        return AVERROR(EIO);
311

    
312
    pkt->pts = curtime;
313

    
314
    /* read one frame */
315
    if (s->use_mmap) {
316
        return v4l_mm_read_picture(s, pkt->data);
317
    } else {
318
        if (read(s->fd, pkt->data, pkt->size) != pkt->size)
319
            return AVERROR(EIO);
320
        return s->frame_size;
321
    }
322
}
323

    
324
static int grab_read_close(AVFormatContext *s1)
325
{
326
    VideoData *s = s1->priv_data;
327

    
328
    if (s->use_mmap)
329
        munmap(s->video_buf, s->gb_buffers.size);
330

    
331
    /* mute audio. we must force it because the BTTV driver does not
332
       return its state correctly */
333
    s->audio_saved.flags |= VIDEO_AUDIO_MUTE;
334
    ioctl(s->fd, VIDIOCSAUDIO, &s->audio_saved);
335

    
336
    close(s->fd);
337
    return 0;
338
}
339

    
340
AVInputFormat v4l_demuxer = {
341
    "video4linux",
342
    NULL_IF_CONFIG_SMALL("Video4Linux device grab"),
343
    sizeof(VideoData),
344
    NULL,
345
    grab_read_header,
346
    grab_read_packet,
347
    grab_read_close,
348
    .flags = AVFMT_NOFILE,
349
};