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ffmpeg / libavdevice / v4l2.c @ 831ec935

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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
7
 * (http://v4l2spec.bytesex.org/v4l2spec/capture.c)
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 *
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 * Thanks to Michael Niedermayer for providing the mapping between
10
 * V4L2_PIX_FMT_* and PIX_FMT_*
11
 *
12
 *
13
 * This file is part of FFmpeg.
14
 *
15
 * 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
22
 * 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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 *
25
 * You should have received a copy of the GNU Lesser General Public
26
 * License along with FFmpeg; if not, write to the Free Software
27
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
28
 */
29

    
30
#include "config.h"
31
#include "libavformat/avformat.h"
32
#include <unistd.h>
33
#include <fcntl.h>
34
#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>
38
#include <linux/videodev2.h>
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#include <time.h>
40

    
41
static const int desired_video_buffers = 256;
42

    
43
enum io_method {
44
    io_read,
45
    io_mmap,
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    io_userptr
47
};
48

    
49
struct video_data {
50
    int fd;
51
    int frame_format; /* V4L2_PIX_FMT_* */
52
    enum io_method io_method;
53
    int width, height;
54
    int frame_rate;
55
    int frame_rate_base;
56
    int frame_size;
57
    int top_field_first;
58

    
59
    int buffers;
60
    void **buf_start;
61
    unsigned int *buf_len;
62
};
63

    
64
struct buff_data {
65
    int index;
66
    int fd;
67
};
68

    
69
struct fmt_map {
70
    enum PixelFormat ff_fmt;
71
    int32_t v4l2_fmt;
72
};
73

    
74
static struct fmt_map fmt_conversion_table[] = {
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    {
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        .ff_fmt = PIX_FMT_YUV420P,
77
        .v4l2_fmt = V4L2_PIX_FMT_YUV420,
78
    },
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    {
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        .ff_fmt = PIX_FMT_YUV422P,
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        .v4l2_fmt = V4L2_PIX_FMT_YUV422P,
82
    },
83
    {
84
        .ff_fmt = PIX_FMT_YUYV422,
85
        .v4l2_fmt = V4L2_PIX_FMT_YUYV,
86
    },
87
    {
88
        .ff_fmt = PIX_FMT_UYVY422,
89
        .v4l2_fmt = V4L2_PIX_FMT_UYVY,
90
    },
91
    {
92
        .ff_fmt = PIX_FMT_YUV411P,
93
        .v4l2_fmt = V4L2_PIX_FMT_YUV411P,
94
    },
95
    {
96
        .ff_fmt = PIX_FMT_YUV410P,
97
        .v4l2_fmt = V4L2_PIX_FMT_YUV410,
98
    },
99
    {
100
        .ff_fmt = PIX_FMT_BGR24,
101
        .v4l2_fmt = V4L2_PIX_FMT_BGR24,
102
    },
103
    {
104
        .ff_fmt = PIX_FMT_RGB24,
105
        .v4l2_fmt = V4L2_PIX_FMT_RGB24,
106
    },
107
    /*
108
    {
109
        .ff_fmt = PIX_FMT_RGB32,
110
        .v4l2_fmt = V4L2_PIX_FMT_BGR32,
111
    },
112
    */
113
    {
114
        .ff_fmt = PIX_FMT_GRAY8,
115
        .v4l2_fmt = V4L2_PIX_FMT_GREY,
116
    },
117
};
118

    
119
static int device_open(AVFormatContext *ctx, uint32_t *capabilities)
120
{
121
    struct v4l2_capability cap;
122
    int fd;
123
    int res;
124
    int flags = O_RDWR;
125

    
126
    if (ctx->flags & AVFMT_FLAG_NONBLOCK) {
127
        flags |= O_NONBLOCK;
128
    }
129
    fd = open(ctx->filename, flags, 0);
130
    if (fd < 0) {
131
        av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s : %s\n",
132
                 ctx->filename, strerror(errno));
133

    
134
        return -1;
135
    }
136

    
137
    res = ioctl(fd, VIDIOC_QUERYCAP, &cap);
138
    // ENOIOCTLCMD definition only availble on __KERNEL__
139
    if (res < 0 && errno == 515)
140
    {
141
        av_log(ctx, AV_LOG_ERROR, "QUERYCAP not implemented, probably V4L device but not supporting V4L2\n");
142
        close(fd);
143

    
144
        return -1;
145
    }
146
    if (res < 0) {
147
        av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
148
                 strerror(errno));
149
        close(fd);
150

    
151
        return -1;
152
    }
153
    if ((cap.capabilities & V4L2_CAP_VIDEO_CAPTURE) == 0) {
154
        av_log(ctx, AV_LOG_ERROR, "Not a video capture device\n");
155
        close(fd);
156

    
157
        return -1;
158
    }
159
    *capabilities = cap.capabilities;
160

    
161
    return fd;
162
}
163

    
164
static int device_init(AVFormatContext *ctx, int *width, int *height, int pix_fmt)
165
{
166
    struct video_data *s = ctx->priv_data;
167
    int fd = s->fd;
168
    struct v4l2_format fmt;
169
    int res;
170

    
171
    memset(&fmt, 0, sizeof(struct v4l2_format));
172
    fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
173
    fmt.fmt.pix.width = *width;
174
    fmt.fmt.pix.height = *height;
175
    fmt.fmt.pix.pixelformat = pix_fmt;
176
    fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;
177
    res = ioctl(fd, VIDIOC_S_FMT, &fmt);
178
    if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {
179
        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);
180
        *width = fmt.fmt.pix.width;
181
        *height = fmt.fmt.pix.height;
182
    }
183

    
184
    return res;
185
}
186

    
187
static int first_field(int fd)
188
{
189
    int res;
190
    v4l2_std_id std;
191

    
192
    res = ioctl(fd, VIDIOC_G_STD, &std);
193
    if (res < 0) {
194
        return 0;
195
    }
196
    if (std & V4L2_STD_NTSC) {
197
        return 0;
198
    }
199

    
200
    return 1;
201
}
202

    
203
static uint32_t fmt_ff2v4l(enum PixelFormat pix_fmt)
204
{
205
    int i;
206

    
207
    for (i = 0; i < sizeof(fmt_conversion_table) / sizeof(struct fmt_map); i++) {
208
        if (fmt_conversion_table[i].ff_fmt == pix_fmt) {
209
            return fmt_conversion_table[i].v4l2_fmt;
210
        }
211
    }
212

    
213
    return 0;
214
}
215

    
216
static enum PixelFormat fmt_v4l2ff(uint32_t pix_fmt)
217
{
218
    int i;
219

    
220
    for (i = 0; i < sizeof(fmt_conversion_table) / sizeof(struct fmt_map); i++) {
221
        if (fmt_conversion_table[i].v4l2_fmt == pix_fmt) {
222
            return fmt_conversion_table[i].ff_fmt;
223
        }
224
    }
225

    
226
    return PIX_FMT_NONE;
227
}
228

    
229
static int mmap_init(AVFormatContext *ctx)
230
{
231
    struct video_data *s = ctx->priv_data;
232
    struct v4l2_requestbuffers req;
233
    int i, res;
234

    
235
    memset(&req, 0, sizeof(struct v4l2_requestbuffers));
236
    req.count = desired_video_buffers;
237
    req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
238
    req.memory = V4L2_MEMORY_MMAP;
239
    res = ioctl (s->fd, VIDIOC_REQBUFS, &req);
240
    if (res < 0) {
241
        if (errno == EINVAL) {
242
            av_log(ctx, AV_LOG_ERROR, "Device does not support mmap\n");
243
        } else {
244
            av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS)\n");
245
        }
246

    
247
        return -1;
248
    }
249

    
250
    if (req.count < 2) {
251
        av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");
252

    
253
        return -1;
254
    }
255
    s->buffers = req.count;
256
    s->buf_start = av_malloc(sizeof(void *) * s->buffers);
257
    if (s->buf_start == NULL) {
258
        av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
259

    
260
        return -1;
261
    }
262
    s->buf_len = av_malloc(sizeof(unsigned int) * s->buffers);
263
    if (s->buf_len == NULL) {
264
        av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
265
        av_free(s->buf_start);
266

    
267
        return -1;
268
    }
269

    
270
    for (i = 0; i < req.count; i++) {
271
        struct v4l2_buffer buf;
272

    
273
        memset(&buf, 0, sizeof(struct v4l2_buffer));
274
        buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
275
        buf.memory = V4L2_MEMORY_MMAP;
276
        buf.index = i;
277
        res = ioctl (s->fd, VIDIOC_QUERYBUF, &buf);
278
        if (res < 0) {
279
            av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF)\n");
280

    
281
            return -1;
282
        }
283

    
284
        s->buf_len[i] = buf.length;
285
        if (s->buf_len[i] < s->frame_size) {
286
            av_log(ctx, AV_LOG_ERROR, "Buffer len [%d] = %d != %d\n", i, s->buf_len[i], s->frame_size);
287

    
288
            return -1;
289
        }
290
        s->buf_start[i] = mmap (NULL, buf.length,
291
                        PROT_READ | PROT_WRITE, MAP_SHARED, s->fd, buf.m.offset);
292
        if (s->buf_start[i] == MAP_FAILED) {
293
            av_log(ctx, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
294

    
295
            return -1;
296
        }
297
    }
298

    
299
    return 0;
300
}
301

    
302
static int read_init(AVFormatContext *ctx)
303
{
304
    return -1;
305
}
306

    
307
static void mmap_release_buffer(AVPacket *pkt)
308
{
309
    struct v4l2_buffer buf;
310
    int res, fd;
311
    struct buff_data *buf_descriptor = pkt->priv;
312

    
313
    memset(&buf, 0, sizeof(struct v4l2_buffer));
314
    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
315
    buf.memory = V4L2_MEMORY_MMAP;
316
    buf.index = buf_descriptor->index;
317
    fd = buf_descriptor->fd;
318
    av_free(buf_descriptor);
319

    
320
    res = ioctl (fd, VIDIOC_QBUF, &buf);
321
    if (res < 0) {
322
        av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF)\n");
323
    }
324
    pkt->data = NULL;
325
    pkt->size = 0;
326
}
327

    
328
static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
329
{
330
    struct video_data *s = ctx->priv_data;
331
    struct v4l2_buffer buf;
332
    struct buff_data *buf_descriptor;
333
    int res;
334

    
335
    memset(&buf, 0, sizeof(struct v4l2_buffer));
336
    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
337
    buf.memory = V4L2_MEMORY_MMAP;
338

    
339
    /* FIXME: Some special treatment might be needed in case of loss of signal... */
340
    while ((res = ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 && (errno == EINTR));
341
    if (res < 0) {
342
        if (errno == EAGAIN) {
343
            pkt->size = 0;
344

    
345
            return AVERROR(EAGAIN);
346
        }
347
        av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n", strerror(errno));
348

    
349
        return -1;
350
    }
351
    assert (buf.index < s->buffers);
352
    if (buf.bytesused != s->frame_size) {
353
        av_log(ctx, AV_LOG_ERROR, "The v4l2 frame is %d bytes, but %d bytes are expected\n", buf.bytesused, s->frame_size);
354

    
355
        return -1;
356
    }
357

    
358
    /* Image is at s->buff_start[buf.index] */
359
    pkt->data= s->buf_start[buf.index];
360
    pkt->size = buf.bytesused;
361
    pkt->pts = buf.timestamp.tv_sec * INT64_C(1000000) + buf.timestamp.tv_usec;
362
    pkt->destruct = mmap_release_buffer;
363
    buf_descriptor = av_malloc(sizeof(struct buff_data));
364
    if (buf_descriptor == NULL) {
365
        /* Something went wrong... Since av_malloc() failed, we cannot even
366
         * allocate a buffer for memcopying into it
367
         */
368
        av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
369
        res = ioctl (s->fd, VIDIOC_QBUF, &buf);
370

    
371
        return -1;
372
    }
373
    buf_descriptor->fd = s->fd;
374
    buf_descriptor->index = buf.index;
375
    pkt->priv = buf_descriptor;
376

    
377
    return s->buf_len[buf.index];
378
}
379

    
380
static int read_frame(AVFormatContext *ctx, AVPacket *pkt)
381
{
382
    return -1;
383
}
384

    
385
static int mmap_start(AVFormatContext *ctx)
386
{
387
    struct video_data *s = ctx->priv_data;
388
    enum v4l2_buf_type type;
389
    int i, res;
390

    
391
    for (i = 0; i < s->buffers; i++) {
392
        struct v4l2_buffer buf;
393

    
394
        memset(&buf, 0, sizeof(struct v4l2_buffer));
395
        buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
396
        buf.memory = V4L2_MEMORY_MMAP;
397
        buf.index  = i;
398

    
399
        res = ioctl (s->fd, VIDIOC_QBUF, &buf);
400
        if (res < 0) {
401
            av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", strerror(errno));
402

    
403
            return -1;
404
        }
405
    }
406

    
407
    type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
408
    res = ioctl (s->fd, VIDIOC_STREAMON, &type);
409
    if (res < 0) {
410
        av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n", strerror(errno));
411

    
412
        return -1;
413
    }
414

    
415
    return 0;
416
}
417

    
418
static void mmap_close(struct video_data *s)
419
{
420
    enum v4l2_buf_type type;
421
    int i;
422

    
423
    type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
424
    /* We do not check for the result, because we could
425
     * not do anything about it anyway...
426
     */
427
    ioctl(s->fd, VIDIOC_STREAMOFF, &type);
428
    for (i = 0; i < s->buffers; i++) {
429
        munmap(s->buf_start[i], s->buf_len[i]);
430
    }
431
    av_free(s->buf_start);
432
    av_free(s->buf_len);
433
}
434

    
435
static int v4l2_set_parameters( AVFormatContext *s1, AVFormatParameters *ap )
436
{
437
    struct video_data *s = s1->priv_data;
438
    struct v4l2_input input;
439
    struct v4l2_standard standard;
440
    int i;
441

    
442
    if(ap->channel>=0) {
443
        /* set tv video input */
444
        memset (&input, 0, sizeof (input));
445
        input.index = ap->channel;
446
        if(ioctl (s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
447
            av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl enum input failed:\n");
448
            return AVERROR(EIO);
449
        }
450

    
451
        av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set input_id: %d, input: %s\n",
452
               ap->channel, input.name);
453
        if(ioctl (s->fd, VIDIOC_S_INPUT, &input.index) < 0 ) {
454
            av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set input(%d) failed\n",
455
                   ap->channel);
456
            return AVERROR(EIO);
457
        }
458
    }
459

    
460
    if(ap->standard) {
461
        av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s\n",
462
               ap->standard );
463
        /* set tv standard */
464
        memset (&standard, 0, sizeof (standard));
465
        for(i=0;;i++) {
466
            standard.index = i;
467
            if (ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
468
                av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set standard(%s) failed\n",
469
                       ap->standard);
470
                return AVERROR(EIO);
471
            }
472

    
473
            if(!strcasecmp(standard.name, ap->standard)) {
474
                break;
475
            }
476
        }
477

    
478
        av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s, id: %"PRIu64"\n",
479
               ap->standard, standard.id);
480
        if (ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
481
            av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set standard(%s) failed\n",
482
                   ap->standard);
483
            return AVERROR(EIO);
484
        }
485
    }
486

    
487
    return 0;
488
}
489

    
490
static int v4l2_read_header(AVFormatContext *s1, AVFormatParameters *ap)
491
{
492
    struct video_data *s = s1->priv_data;
493
    AVStream *st;
494
    int width, height;
495
    int res, frame_rate, frame_rate_base;
496
    uint32_t desired_format, capabilities;
497

    
498
    if (ap->width <= 0 || ap->height <= 0 || ap->time_base.den <= 0) {
499
        av_log(s1, AV_LOG_ERROR, "Missing/Wrong width, height or framerate\n");
500

    
501
        return -1;
502
    }
503

    
504
    width = ap->width;
505
    height = ap->height;
506
    frame_rate = ap->time_base.den;
507
    frame_rate_base = ap->time_base.num;
508

    
509
    if((unsigned)width > 32767 || (unsigned)height > 32767) {
510
        av_log(s1, AV_LOG_ERROR, "Wrong size %dx%d\n", width, height);
511

    
512
        return -1;
513
    }
514

    
515
    st = av_new_stream(s1, 0);
516
    if (!st) {
517
        return AVERROR(ENOMEM);
518
    }
519
    av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
520

    
521
    s->width = width;
522
    s->height = height;
523
    s->frame_rate      = frame_rate;
524
    s->frame_rate_base = frame_rate_base;
525

    
526
    capabilities = 0;
527
    s->fd = device_open(s1, &capabilities);
528
    if (s->fd < 0) {
529
        av_free(st);
530

    
531
        return AVERROR(EIO);
532
    }
533
    av_log(s1, AV_LOG_INFO, "[%d]Capabilities: %x\n", s->fd, capabilities);
534

    
535
    desired_format = fmt_ff2v4l(ap->pix_fmt);
536
    if (desired_format == 0 || (device_init(s1, &width, &height, desired_format) < 0)) {
537
        int i, done;
538

    
539
        done = 0; i = 0;
540
        while (!done) {
541
            desired_format = fmt_conversion_table[i].v4l2_fmt;
542
            if (device_init(s1, &width, &height, desired_format) < 0) {
543
                desired_format = 0;
544
                i++;
545
            } else {
546
               done = 1;
547
            }
548
            if (i == sizeof(fmt_conversion_table) / sizeof(struct fmt_map)) {
549
               done = 1;
550
            }
551
        }
552
    }
553
    if (desired_format == 0) {
554
        av_log(s1, AV_LOG_ERROR, "Cannot find a proper format.\n");
555
        close(s->fd);
556
        av_free(st);
557

    
558
        return AVERROR(EIO);
559
    }
560
    s->frame_format = desired_format;
561

    
562
    if( v4l2_set_parameters( s1, ap ) < 0 )
563
        return AVERROR(EIO);
564

    
565
    st->codec->pix_fmt = fmt_v4l2ff(desired_format);
566
    s->frame_size = avpicture_get_size(st->codec->pix_fmt, width, height);
567
    if (capabilities & V4L2_CAP_STREAMING) {
568
        s->io_method = io_mmap;
569
        res = mmap_init(s1);
570
        if (res == 0) {
571
            res = mmap_start(s1);
572
        }
573
    } else {
574
        s->io_method = io_read;
575
        res = read_init(s1);
576
    }
577
    if (res < 0) {
578
        close(s->fd);
579
        av_free(st);
580

    
581
        return AVERROR(EIO);
582
    }
583
    s->top_field_first = first_field(s->fd);
584

    
585
    st->codec->codec_type = CODEC_TYPE_VIDEO;
586
    st->codec->codec_id = CODEC_ID_RAWVIDEO;
587
    st->codec->width = width;
588
    st->codec->height = height;
589
    st->codec->time_base.den = frame_rate;
590
    st->codec->time_base.num = frame_rate_base;
591
    st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;
592

    
593
    return 0;
594
}
595

    
596
static int v4l2_read_packet(AVFormatContext *s1, AVPacket *pkt)
597
{
598
    struct video_data *s = s1->priv_data;
599
    int res;
600

    
601
    if (s->io_method == io_mmap) {
602
        av_init_packet(pkt);
603
        res = mmap_read_frame(s1, pkt);
604
    } else if (s->io_method == io_read) {
605
        if (av_new_packet(pkt, s->frame_size) < 0)
606
            return AVERROR(EIO);
607

    
608
        res = read_frame(s1, pkt);
609
    } else {
610
        return AVERROR(EIO);
611
    }
612
    if (res < 0) {
613
        return res;
614
    }
615

    
616
    if (s1->streams[0]->codec->coded_frame) {
617
        s1->streams[0]->codec->coded_frame->interlaced_frame = 1;
618
        s1->streams[0]->codec->coded_frame->top_field_first = s->top_field_first;
619
    }
620

    
621
    return s->frame_size;
622
}
623

    
624
static int v4l2_read_close(AVFormatContext *s1)
625
{
626
    struct video_data *s = s1->priv_data;
627

    
628
    if (s->io_method == io_mmap) {
629
        mmap_close(s);
630
    }
631

    
632
    close(s->fd);
633
    return 0;
634
}
635

    
636
AVInputFormat v4l2_demuxer = {
637
    "video4linux2",
638
    NULL_IF_CONFIG_SMALL("video grab"),
639
    sizeof(struct video_data),
640
    NULL,
641
    v4l2_read_header,
642
    v4l2_read_packet,
643
    v4l2_read_close,
644
    .flags = AVFMT_NOFILE,
645
};