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ffmpeg / libavformat / v4l2.c @ e4dd03f3

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1
/*
2
 * Video4Linux2 grab interface
3
 * Copyright (c) 2000,2001 Fabrice Bellard.
4
 * Copyright (c) 2006 Luca Abeni.
5
 *
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 * Part of this file is based on the V4L2 video capture example
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 * (http://v4l2spec.bytesex.org/v4l2spec/capture.c)
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 *
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 * Thanks to Michael Niedermayer for providing the mapping between
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 * V4L2_PIX_FMT_* and PIX_FMT_*
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 *
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
16
 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
21
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
28
 */
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#include "avformat.h"
30
#include <unistd.h>
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#include <fcntl.h>
32
#include <sys/ioctl.h>
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#include <sys/mman.h>
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#include <sys/time.h>
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#include <asm/types.h>
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#include <linux/videodev2.h>
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#include <time.h>
38

    
39
static const int desired_video_buffers = 256;
40

    
41
enum io_method {
42
    io_read,
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    io_mmap,
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    io_userptr
45
};
46

    
47
struct video_data {
48
    int fd;
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    int frame_format; /* V4L2_PIX_FMT_* */
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    enum io_method io_method;
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    int width, height;
52
    int frame_rate;
53
    int frame_rate_base;
54
    int frame_size;
55
    int top_field_first;
56

    
57
    int buffers;
58
    void **buf_start;
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    unsigned int *buf_len;
60
};
61

    
62
struct buff_data {
63
    int index;
64
    int fd;
65
};
66

    
67
struct fmt_map {
68
    enum PixelFormat ff_fmt;
69
    int32_t v4l2_fmt;
70
};
71

    
72
static struct fmt_map fmt_conversion_table[] = {
73
    {
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        .ff_fmt = PIX_FMT_YUV420P,
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        .v4l2_fmt = V4L2_PIX_FMT_YUV420,
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    },
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    {
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        .ff_fmt = PIX_FMT_YUV422P,
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        .v4l2_fmt = V4L2_PIX_FMT_YUV422P,
80
    },
81
    {
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        .ff_fmt = PIX_FMT_YUYV422,
83
        .v4l2_fmt = V4L2_PIX_FMT_YUYV,
84
    },
85
    {
86
        .ff_fmt = PIX_FMT_UYVY422,
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        .v4l2_fmt = V4L2_PIX_FMT_UYVY,
88
    },
89
    {
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        .ff_fmt = PIX_FMT_YUV411P,
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        .v4l2_fmt = V4L2_PIX_FMT_YUV411P,
92
    },
93
    {
94
        .ff_fmt = PIX_FMT_YUV410P,
95
        .v4l2_fmt = V4L2_PIX_FMT_YUV410,
96
    },
97
    {
98
        .ff_fmt = PIX_FMT_BGR24,
99
        .v4l2_fmt = V4L2_PIX_FMT_BGR24,
100
    },
101
    {
102
        .ff_fmt = PIX_FMT_RGB24,
103
        .v4l2_fmt = V4L2_PIX_FMT_RGB24,
104
    },
105
    /*
106
    {
107
        .ff_fmt = PIX_FMT_RGB32,
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        .v4l2_fmt = V4L2_PIX_FMT_BGR32,
109
    },
110
    */
111
    {
112
        .ff_fmt = PIX_FMT_GRAY8,
113
        .v4l2_fmt = V4L2_PIX_FMT_GREY,
114
    },
115
};
116

    
117
static int device_open(AVFormatContext *ctx, uint32_t *capabilities)
118
{
119
    struct v4l2_capability cap;
120
    int fd;
121
    int res;
122

    
123
    fd = open(ctx->filename, O_RDWR /*| O_NONBLOCK*/, 0);
124
    if (fd < 0) {
125
        av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s : %s\n",
126
                 ctx->filename, strerror(errno));
127

    
128
        return -1;
129
    }
130

    
131
    res = ioctl(fd, VIDIOC_QUERYCAP, &cap);
132
    // ENOIOCTLCMD definition only availble on __KERNEL__
133
    if (res < 0 && errno == 515)
134
    {
135
        av_log(ctx, AV_LOG_ERROR, "QUERYCAP not implemented, probably V4L device but not supporting V4L2\n");
136
        close(fd);
137

    
138
        return -1;
139
    }
140
    if (res < 0) {
141
        av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
142
                 strerror(errno));
143
        close(fd);
144

    
145
        return -1;
146
    }
147
    if ((cap.capabilities & V4L2_CAP_VIDEO_CAPTURE) == 0) {
148
        av_log(ctx, AV_LOG_ERROR, "Not a video capture device\n");
149
        close(fd);
150

    
151
        return -1;
152
    }
153
    *capabilities = cap.capabilities;
154

    
155
    return fd;
156
}
157

    
158
static int device_init(AVFormatContext *ctx, int *width, int *height, int pix_fmt)
159
{
160
    struct video_data *s = ctx->priv_data;
161
    int fd = s->fd;
162
    struct v4l2_format fmt;
163
    int res;
164

    
165
    memset(&fmt, 0, sizeof(struct v4l2_format));
166
    fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
167
    fmt.fmt.pix.width = *width;
168
    fmt.fmt.pix.height = *height;
169
    fmt.fmt.pix.pixelformat = pix_fmt;
170
    fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;
171
    res = ioctl(fd, VIDIOC_S_FMT, &fmt);
172
    if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {
173
        av_log(ctx, AV_LOG_INFO, "The V4L2 driver changed the video from %dx%d to %dx%d\n", *width, *height, fmt.fmt.pix.width, fmt.fmt.pix.height);
174
        *width = fmt.fmt.pix.width;
175
        *height = fmt.fmt.pix.height;
176
    }
177

    
178
    return res;
179
}
180

    
181
static int first_field(int fd)
182
{
183
    int res;
184
    v4l2_std_id std;
185

    
186
    res = ioctl(fd, VIDIOC_G_STD, &std);
187
    if (res < 0) {
188
        return 0;
189
    }
190
    if (std & V4L2_STD_NTSC) {
191
        return 0;
192
    }
193

    
194
    return 1;
195
}
196

    
197
static uint32_t fmt_ff2v4l(enum PixelFormat pix_fmt)
198
{
199
    int i;
200

    
201
    for (i = 0; i < sizeof(fmt_conversion_table) / sizeof(struct fmt_map); i++) {
202
        if (fmt_conversion_table[i].ff_fmt == pix_fmt) {
203
            return fmt_conversion_table[i].v4l2_fmt;
204
        }
205
    }
206

    
207
    return 0;
208
}
209

    
210
static enum PixelFormat fmt_v4l2ff(uint32_t pix_fmt)
211
{
212
    int i;
213

    
214
    for (i = 0; i < sizeof(fmt_conversion_table) / sizeof(struct fmt_map); i++) {
215
        if (fmt_conversion_table[i].v4l2_fmt == pix_fmt) {
216
            return fmt_conversion_table[i].ff_fmt;
217
        }
218
    }
219

    
220
    return -1;
221
}
222

    
223
static int mmap_init(AVFormatContext *ctx)
224
{
225
    struct video_data *s = ctx->priv_data;
226
    struct v4l2_requestbuffers req;
227
    int i, res;
228

    
229
    memset(&req, 0, sizeof(struct v4l2_requestbuffers));
230
    req.count = desired_video_buffers;
231
    req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
232
    req.memory = V4L2_MEMORY_MMAP;
233
    res = ioctl (s->fd, VIDIOC_REQBUFS, &req);
234
    if (res < 0) {
235
        if (errno == EINVAL) {
236
            av_log(ctx, AV_LOG_ERROR, "Device does not support mmap\n");
237
        } else {
238
            av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS)\n");
239
        }
240

    
241
        return -1;
242
    }
243

    
244
    if (req.count < 2) {
245
        av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");
246

    
247
        return -1;
248
    }
249
    s->buffers = req.count;
250
    s->buf_start = av_malloc(sizeof(void *) * s->buffers);
251
    if (s->buf_start == NULL) {
252
        av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
253

    
254
        return -1;
255
    }
256
    s->buf_len = av_malloc(sizeof(unsigned int) * s->buffers);
257
    if (s->buf_len == NULL) {
258
        av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
259
        av_free(s->buf_start);
260

    
261
        return -1;
262
    }
263

    
264
    for (i = 0; i < req.count; i++) {
265
        struct v4l2_buffer buf;
266

    
267
        memset(&buf, 0, sizeof(struct v4l2_buffer));
268
        buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
269
        buf.memory = V4L2_MEMORY_MMAP;
270
        buf.index = i;
271
        res = ioctl (s->fd, VIDIOC_QUERYBUF, &buf);
272
        if (res < 0) {
273
            av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF)\n");
274

    
275
            return -1;
276
        }
277

    
278
        s->buf_len[i] = buf.length;
279
        if (s->buf_len[i] < s->frame_size) {
280
            av_log(ctx, AV_LOG_ERROR, "Buffer len [%d] = %d != %d\n", i, s->buf_len[i], s->frame_size);
281

    
282
            return -1;
283
        }
284
        s->buf_start[i] = mmap (NULL, buf.length,
285
                        PROT_READ | PROT_WRITE, MAP_SHARED, s->fd, buf.m.offset);
286
        if (s->buf_start[i] == MAP_FAILED) {
287
            av_log(ctx, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
288

    
289
            return -1;
290
        }
291
    }
292

    
293
    return 0;
294
}
295

    
296
static int read_init(AVFormatContext *ctx)
297
{
298
    return -1;
299
}
300

    
301
static void mmap_release_buffer(AVPacket *pkt)
302
{
303
    struct v4l2_buffer buf;
304
    int res, fd;
305
    struct buff_data *buf_descriptor = pkt->priv;
306

    
307
    memset(&buf, 0, sizeof(struct v4l2_buffer));
308
    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
309
    buf.memory = V4L2_MEMORY_MMAP;
310
    buf.index = buf_descriptor->index;
311
    fd = buf_descriptor->fd;
312
    av_free(buf_descriptor);
313

    
314
    res = ioctl (fd, VIDIOC_QBUF, &buf);
315
    if (res < 0) {
316
        av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF)\n");
317
    }
318
    pkt->data = NULL;
319
    pkt->size = 0;
320
}
321

    
322
static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
323
{
324
    struct video_data *s = ctx->priv_data;
325
    struct v4l2_buffer buf;
326
    struct buff_data *buf_descriptor;
327
    int res;
328

    
329
    memset(&buf, 0, sizeof(struct v4l2_buffer));
330
    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
331
    buf.memory = V4L2_MEMORY_MMAP;
332

    
333
    /* FIXME: Some special treatment might be needed in case of loss of signal... */
334
    while ((res = ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 &&
335
           ((errno == EAGAIN) || (errno == EINTR)));
336
    if (res < 0) {
337
        av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n", strerror(errno));
338

    
339
        return -1;
340
    }
341
    assert (buf.index < s->buffers);
342
    if (buf.bytesused != s->frame_size) {
343
        av_log(ctx, AV_LOG_ERROR, "The v4l2 frame is %d bytes, but %d bytes are expected\n", buf.bytesused, s->frame_size);
344

    
345
        return -1;
346
    }
347

    
348
    /* Image is at s->buff_start[buf.index] */
349
    pkt->data= s->buf_start[buf.index];
350
    pkt->size = buf.bytesused;
351
    pkt->pts = buf.timestamp.tv_sec * INT64_C(1000000) + buf.timestamp.tv_usec;
352
    pkt->destruct = mmap_release_buffer;
353
    buf_descriptor = av_malloc(sizeof(struct buff_data));
354
    if (buf_descriptor == NULL) {
355
        /* Something went wrong... Since av_malloc() failed, we cannot even
356
         * allocate a buffer for memcopying into it
357
         */
358
        av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
359
        res = ioctl (s->fd, VIDIOC_QBUF, &buf);
360

    
361
        return -1;
362
    }
363
    buf_descriptor->fd = s->fd;
364
    buf_descriptor->index = buf.index;
365
    pkt->priv = buf_descriptor;
366

    
367
    return s->buf_len[buf.index];
368
}
369

    
370
static int read_frame(AVFormatContext *ctx, AVPacket *pkt)
371
{
372
    return -1;
373
}
374

    
375
static int mmap_start(AVFormatContext *ctx)
376
{
377
    struct video_data *s = ctx->priv_data;
378
    enum v4l2_buf_type type;
379
    int i, res;
380

    
381
    for (i = 0; i < s->buffers; i++) {
382
        struct v4l2_buffer buf;
383

    
384
        memset(&buf, 0, sizeof(struct v4l2_buffer));
385
        buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
386
        buf.memory = V4L2_MEMORY_MMAP;
387
        buf.index  = i;
388

    
389
        res = ioctl (s->fd, VIDIOC_QBUF, &buf);
390
        if (res < 0) {
391
            av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", strerror(errno));
392

    
393
            return -1;
394
        }
395
    }
396

    
397
    type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
398
    res = ioctl (s->fd, VIDIOC_STREAMON, &type);
399
    if (res < 0) {
400
        av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n", strerror(errno));
401

    
402
        return -1;
403
    }
404

    
405
    return 0;
406
}
407

    
408
static void mmap_close(struct video_data *s)
409
{
410
    enum v4l2_buf_type type;
411
    int i;
412

    
413
    type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
414
    /* We do not check for the result, because we could
415
     * not do anything about it anyway...
416
     */
417
    ioctl(s->fd, VIDIOC_STREAMOFF, &type);
418
    for (i = 0; i < s->buffers; i++) {
419
        munmap(s->buf_start[i], s->buf_len[i]);
420
    }
421
    av_free(s->buf_start);
422
    av_free(s->buf_len);
423
}
424

    
425
static int v4l2_set_parameters( AVFormatContext *s1, AVFormatParameters *ap )
426
{
427
    struct video_data *s = s1->priv_data;
428
    struct v4l2_input input;
429
    struct v4l2_standard standard;
430
    int i;
431

    
432
    if(ap->channel>=0) {
433
        /* set tv video input */
434
        memset (&input, 0, sizeof (input));
435
        input.index = ap->channel;
436
        if(ioctl (s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
437
            av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl enum input failed:\n");
438
            return AVERROR_IO;
439
        }
440

    
441
        av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set input_id: %d, input: %s\n",
442
               ap->channel, input.name);
443
        if(ioctl (s->fd, VIDIOC_S_INPUT, &input.index) < 0 ) {
444
            av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set input(%d) failed\n",
445
                   ap->channel);
446
            return AVERROR_IO;
447
        }
448
    }
449

    
450
    if(ap->standard) {
451
        av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s\n",
452
               ap->standard );
453
        /* set tv standard */
454
        memset (&standard, 0, sizeof (standard));
455
        for(i=0;;i++) {
456
            standard.index = i;
457
            if (ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
458
                av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set standard(%s) failed\n",
459
                       ap->standard);
460
                return AVERROR_IO;
461
            }
462

    
463
            if(!strcasecmp(standard.name, ap->standard)) {
464
                break;
465
            }
466
        }
467

    
468
        av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s, id: %"PRIu64"\n",
469
               ap->standard, standard.id);
470
        if (ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
471
            av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set standard(%s) failed\n",
472
                   ap->standard);
473
            return AVERROR_IO;
474
        }
475
    }
476

    
477
    return 0;
478
}
479

    
480
static int v4l2_read_header(AVFormatContext *s1, AVFormatParameters *ap)
481
{
482
    struct video_data *s = s1->priv_data;
483
    AVStream *st;
484
    int width, height;
485
    int res, frame_rate, frame_rate_base;
486
    uint32_t desired_format, capabilities;
487

    
488
    if (ap->width <= 0 || ap->height <= 0 || ap->time_base.den <= 0) {
489
        av_log(s1, AV_LOG_ERROR, "Missing/Wrong parameters\n");
490

    
491
        return -1;
492
    }
493

    
494
    width = ap->width;
495
    height = ap->height;
496
    frame_rate = ap->time_base.den;
497
    frame_rate_base = ap->time_base.num;
498

    
499
    if((unsigned)width > 32767 || (unsigned)height > 32767) {
500
        av_log(s1, AV_LOG_ERROR, "Wrong size %dx%d\n", width, height);
501

    
502
        return -1;
503
    }
504

    
505
    st = av_new_stream(s1, 0);
506
    if (!st) {
507
        return AVERROR(ENOMEM);
508
    }
509
    av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
510

    
511
    s->width = width;
512
    s->height = height;
513
    s->frame_rate      = frame_rate;
514
    s->frame_rate_base = frame_rate_base;
515

    
516
    capabilities = 0;
517
    s->fd = device_open(s1, &capabilities);
518
    if (s->fd < 0) {
519
        av_free(st);
520

    
521
        return AVERROR_IO;
522
    }
523
    av_log(s1, AV_LOG_INFO, "[%d]Capabilities: %x\n", s->fd, capabilities);
524

    
525
    desired_format = fmt_ff2v4l(ap->pix_fmt);
526
    if (desired_format == 0 || (device_init(s1, &width, &height, desired_format) < 0)) {
527
        int i, done;
528

    
529
        done = 0; i = 0;
530
        while (!done) {
531
            desired_format = fmt_conversion_table[i].v4l2_fmt;
532
            if (device_init(s1, &width, &height, desired_format) < 0) {
533
                desired_format = 0;
534
                i++;
535
            } else {
536
               done = 1;
537
            }
538
            if (i == sizeof(fmt_conversion_table) / sizeof(struct fmt_map)) {
539
               done = 1;
540
            }
541
        }
542
    }
543
    if (desired_format == 0) {
544
        av_log(s1, AV_LOG_ERROR, "Cannot find a proper format.\n");
545
        close(s->fd);
546
        av_free(st);
547

    
548
        return AVERROR_IO;
549
    }
550
    s->frame_format = desired_format;
551

    
552
    if( v4l2_set_parameters( s1, ap ) < 0 )
553
        return AVERROR_IO;
554

    
555
    st->codec->pix_fmt = fmt_v4l2ff(desired_format);
556
    s->frame_size = avpicture_get_size(st->codec->pix_fmt, width, height);
557
    if (capabilities & V4L2_CAP_STREAMING) {
558
        s->io_method = io_mmap;
559
        res = mmap_init(s1);
560
        if (res == 0) {
561
            res = mmap_start(s1);
562
        }
563
    } else {
564
        s->io_method = io_read;
565
        res = read_init(s1);
566
    }
567
    if (res < 0) {
568
        close(s->fd);
569
        av_free(st);
570

    
571
        return AVERROR_IO;
572
    }
573
    s->top_field_first = first_field(s->fd);
574

    
575
    st->codec->codec_type = CODEC_TYPE_VIDEO;
576
    st->codec->codec_id = CODEC_ID_RAWVIDEO;
577
    st->codec->width = width;
578
    st->codec->height = height;
579
    st->codec->time_base.den = frame_rate;
580
    st->codec->time_base.num = frame_rate_base;
581
    st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;
582

    
583
    return 0;
584
}
585

    
586
static int v4l2_read_packet(AVFormatContext *s1, AVPacket *pkt)
587
{
588
    struct video_data *s = s1->priv_data;
589
    int res;
590

    
591
    if (s->io_method == io_mmap) {
592
        av_init_packet(pkt);
593
        res = mmap_read_frame(s1, pkt);
594
    } else if (s->io_method == io_read) {
595
        if (av_new_packet(pkt, s->frame_size) < 0)
596
            return AVERROR_IO;
597

    
598
        res = read_frame(s1, pkt);
599
    } else {
600
        return AVERROR_IO;
601
    }
602
    if (res < 0) {
603
        return AVERROR_IO;
604
    }
605

    
606
    if (s1->streams[0]->codec->coded_frame) {
607
        s1->streams[0]->codec->coded_frame->interlaced_frame = 1;
608
        s1->streams[0]->codec->coded_frame->top_field_first = s->top_field_first;
609
    }
610

    
611
    return s->frame_size;
612
}
613

    
614
static int v4l2_read_close(AVFormatContext *s1)
615
{
616
    struct video_data *s = s1->priv_data;
617

    
618
    if (s->io_method == io_mmap) {
619
        mmap_close(s);
620
    }
621

    
622
    close(s->fd);
623
    return 0;
624
}
625

    
626
AVInputFormat v4l2_demuxer = {
627
    "video4linux2",
628
    "video grab",
629
    sizeof(struct video_data),
630
    NULL,
631
    v4l2_read_header,
632
    v4l2_read_packet,
633
    v4l2_read_close,
634
    .flags = AVFMT_NOFILE,
635
};