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ffmpeg / libavdevice / v4l2.c @ e7b987dc

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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
10
 * 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
22
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
24
 *
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 * 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
#undef __STRICT_ANSI__ //workaround due to broken kernel headers
31
#include "config.h"
32
#include "libavformat/avformat.h"
33
#include <unistd.h>
34
#include <fcntl.h>
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#include <sys/ioctl.h>
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#include <sys/mman.h>
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#include <sys/time.h>
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#ifdef HAVE_SYS_VIDEOIO_H
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#include <sys/videoio.h>
40
#else
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#include <asm/types.h>
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#include <linux/videodev2.h>
43
#endif
44
#include <time.h>
45
#include <strings.h>
46

    
47
static const int desired_video_buffers = 256;
48

    
49
enum io_method {
50
    io_read,
51
    io_mmap,
52
    io_userptr
53
};
54

    
55
struct video_data {
56
    int fd;
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    int frame_format; /* V4L2_PIX_FMT_* */
58
    enum io_method io_method;
59
    int width, height;
60
    int frame_size;
61
    int top_field_first;
62

    
63
    int buffers;
64
    void **buf_start;
65
    unsigned int *buf_len;
66
};
67

    
68
struct buff_data {
69
    int index;
70
    int fd;
71
};
72

    
73
struct fmt_map {
74
    enum PixelFormat ff_fmt;
75
    int32_t v4l2_fmt;
76
};
77

    
78
static struct fmt_map fmt_conversion_table[] = {
79
    {
80
        .ff_fmt = PIX_FMT_YUV420P,
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        .v4l2_fmt = V4L2_PIX_FMT_YUV420,
82
    },
83
    {
84
        .ff_fmt = PIX_FMT_YUV422P,
85
        .v4l2_fmt = V4L2_PIX_FMT_YUV422P,
86
    },
87
    {
88
        .ff_fmt = PIX_FMT_YUYV422,
89
        .v4l2_fmt = V4L2_PIX_FMT_YUYV,
90
    },
91
    {
92
        .ff_fmt = PIX_FMT_UYVY422,
93
        .v4l2_fmt = V4L2_PIX_FMT_UYVY,
94
    },
95
    {
96
        .ff_fmt = PIX_FMT_YUV411P,
97
        .v4l2_fmt = V4L2_PIX_FMT_YUV411P,
98
    },
99
    {
100
        .ff_fmt = PIX_FMT_YUV410P,
101
        .v4l2_fmt = V4L2_PIX_FMT_YUV410,
102
    },
103
    {
104
        .ff_fmt = PIX_FMT_RGB555,
105
        .v4l2_fmt = V4L2_PIX_FMT_RGB555,
106
    },
107
    {
108
        .ff_fmt = PIX_FMT_RGB565,
109
        .v4l2_fmt = V4L2_PIX_FMT_RGB565,
110
    },
111
    {
112
        .ff_fmt = PIX_FMT_BGR24,
113
        .v4l2_fmt = V4L2_PIX_FMT_BGR24,
114
    },
115
    {
116
        .ff_fmt = PIX_FMT_RGB24,
117
        .v4l2_fmt = V4L2_PIX_FMT_RGB24,
118
    },
119
    {
120
        .ff_fmt = PIX_FMT_BGRA,
121
        .v4l2_fmt = V4L2_PIX_FMT_BGR32,
122
    },
123
    {
124
        .ff_fmt = PIX_FMT_GRAY8,
125
        .v4l2_fmt = V4L2_PIX_FMT_GREY,
126
    },
127
};
128

    
129
static int device_open(AVFormatContext *ctx, uint32_t *capabilities)
130
{
131
    struct v4l2_capability cap;
132
    int fd;
133
    int res;
134
    int flags = O_RDWR;
135

    
136
    if (ctx->flags & AVFMT_FLAG_NONBLOCK) {
137
        flags |= O_NONBLOCK;
138
    }
139
    fd = open(ctx->filename, flags, 0);
140
    if (fd < 0) {
141
        av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s : %s\n",
142
                 ctx->filename, strerror(errno));
143

    
144
        return -1;
145
    }
146

    
147
    res = ioctl(fd, VIDIOC_QUERYCAP, &cap);
148
    // ENOIOCTLCMD definition only availble on __KERNEL__
149
    if (res < 0 && errno == 515)
150
    {
151
        av_log(ctx, AV_LOG_ERROR, "QUERYCAP not implemented, probably V4L device but not supporting V4L2\n");
152
        close(fd);
153

    
154
        return -1;
155
    }
156
    if (res < 0) {
157
        av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
158
                 strerror(errno));
159
        close(fd);
160

    
161
        return -1;
162
    }
163
    if ((cap.capabilities & V4L2_CAP_VIDEO_CAPTURE) == 0) {
164
        av_log(ctx, AV_LOG_ERROR, "Not a video capture device\n");
165
        close(fd);
166

    
167
        return -1;
168
    }
169
    *capabilities = cap.capabilities;
170

    
171
    return fd;
172
}
173

    
174
static int device_init(AVFormatContext *ctx, int *width, int *height, int pix_fmt)
175
{
176
    struct video_data *s = ctx->priv_data;
177
    int fd = s->fd;
178
    struct v4l2_format fmt;
179
    int res;
180

    
181
    memset(&fmt, 0, sizeof(struct v4l2_format));
182
    fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
183
    fmt.fmt.pix.width = *width;
184
    fmt.fmt.pix.height = *height;
185
    fmt.fmt.pix.pixelformat = pix_fmt;
186
    fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;
187
    res = ioctl(fd, VIDIOC_S_FMT, &fmt);
188
    if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {
189
        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);
190
        *width = fmt.fmt.pix.width;
191
        *height = fmt.fmt.pix.height;
192
    }
193

    
194
    if (pix_fmt != fmt.fmt.pix.pixelformat) {
195
        av_log(ctx, AV_LOG_DEBUG, "The V4L2 driver changed the pixel format from 0x%08X to 0x%08X\n", pix_fmt, fmt.fmt.pix.pixelformat);
196
        res = -1;
197
    }
198

    
199
    return res;
200
}
201

    
202
static int first_field(int fd)
203
{
204
    int res;
205
    v4l2_std_id std;
206

    
207
    res = ioctl(fd, VIDIOC_G_STD, &std);
208
    if (res < 0) {
209
        return 0;
210
    }
211
    if (std & V4L2_STD_NTSC) {
212
        return 0;
213
    }
214

    
215
    return 1;
216
}
217

    
218
static uint32_t fmt_ff2v4l(enum PixelFormat pix_fmt)
219
{
220
    int i;
221

    
222
    for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
223
        if (fmt_conversion_table[i].ff_fmt == pix_fmt) {
224
            return fmt_conversion_table[i].v4l2_fmt;
225
        }
226
    }
227

    
228
    return 0;
229
}
230

    
231
static enum PixelFormat fmt_v4l2ff(uint32_t pix_fmt)
232
{
233
    int i;
234

    
235
    for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
236
        if (fmt_conversion_table[i].v4l2_fmt == pix_fmt) {
237
            return fmt_conversion_table[i].ff_fmt;
238
        }
239
    }
240

    
241
    return PIX_FMT_NONE;
242
}
243

    
244
static int mmap_init(AVFormatContext *ctx)
245
{
246
    struct video_data *s = ctx->priv_data;
247
    struct v4l2_requestbuffers req;
248
    int i, res;
249

    
250
    memset(&req, 0, sizeof(struct v4l2_requestbuffers));
251
    req.count = desired_video_buffers;
252
    req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
253
    req.memory = V4L2_MEMORY_MMAP;
254
    res = ioctl (s->fd, VIDIOC_REQBUFS, &req);
255
    if (res < 0) {
256
        if (errno == EINVAL) {
257
            av_log(ctx, AV_LOG_ERROR, "Device does not support mmap\n");
258
        } else {
259
            av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS)\n");
260
        }
261

    
262
        return -1;
263
    }
264

    
265
    if (req.count < 2) {
266
        av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");
267

    
268
        return -1;
269
    }
270
    s->buffers = req.count;
271
    s->buf_start = av_malloc(sizeof(void *) * s->buffers);
272
    if (s->buf_start == NULL) {
273
        av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
274

    
275
        return -1;
276
    }
277
    s->buf_len = av_malloc(sizeof(unsigned int) * s->buffers);
278
    if (s->buf_len == NULL) {
279
        av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
280
        av_free(s->buf_start);
281

    
282
        return -1;
283
    }
284

    
285
    for (i = 0; i < req.count; i++) {
286
        struct v4l2_buffer buf;
287

    
288
        memset(&buf, 0, sizeof(struct v4l2_buffer));
289
        buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
290
        buf.memory = V4L2_MEMORY_MMAP;
291
        buf.index = i;
292
        res = ioctl (s->fd, VIDIOC_QUERYBUF, &buf);
293
        if (res < 0) {
294
            av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF)\n");
295

    
296
            return -1;
297
        }
298

    
299
        s->buf_len[i] = buf.length;
300
        if (s->buf_len[i] < s->frame_size) {
301
            av_log(ctx, AV_LOG_ERROR, "Buffer len [%d] = %d != %d\n", i, s->buf_len[i], s->frame_size);
302

    
303
            return -1;
304
        }
305
        s->buf_start[i] = mmap (NULL, buf.length,
306
                        PROT_READ | PROT_WRITE, MAP_SHARED, s->fd, buf.m.offset);
307
        if (s->buf_start[i] == MAP_FAILED) {
308
            av_log(ctx, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
309

    
310
            return -1;
311
        }
312
    }
313

    
314
    return 0;
315
}
316

    
317
static int read_init(AVFormatContext *ctx)
318
{
319
    return -1;
320
}
321

    
322
static void mmap_release_buffer(AVPacket *pkt)
323
{
324
    struct v4l2_buffer buf;
325
    int res, fd;
326
    struct buff_data *buf_descriptor = pkt->priv;
327

    
328
    memset(&buf, 0, sizeof(struct v4l2_buffer));
329
    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
330
    buf.memory = V4L2_MEMORY_MMAP;
331
    buf.index = buf_descriptor->index;
332
    fd = buf_descriptor->fd;
333
    av_free(buf_descriptor);
334

    
335
    res = ioctl (fd, VIDIOC_QBUF, &buf);
336
    if (res < 0) {
337
        av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF)\n");
338
    }
339
    pkt->data = NULL;
340
    pkt->size = 0;
341
}
342

    
343
static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
344
{
345
    struct video_data *s = ctx->priv_data;
346
    struct v4l2_buffer buf;
347
    struct buff_data *buf_descriptor;
348
    int res;
349

    
350
    memset(&buf, 0, sizeof(struct v4l2_buffer));
351
    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
352
    buf.memory = V4L2_MEMORY_MMAP;
353

    
354
    /* FIXME: Some special treatment might be needed in case of loss of signal... */
355
    while ((res = ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 && (errno == EINTR));
356
    if (res < 0) {
357
        if (errno == EAGAIN) {
358
            pkt->size = 0;
359

    
360
            return AVERROR(EAGAIN);
361
        }
362
        av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n", strerror(errno));
363

    
364
        return -1;
365
    }
366
    assert (buf.index < s->buffers);
367
    if (buf.bytesused != s->frame_size) {
368
        av_log(ctx, AV_LOG_ERROR, "The v4l2 frame is %d bytes, but %d bytes are expected\n", buf.bytesused, s->frame_size);
369

    
370
        return -1;
371
    }
372

    
373
    /* Image is at s->buff_start[buf.index] */
374
    pkt->data= s->buf_start[buf.index];
375
    pkt->size = buf.bytesused;
376
    pkt->pts = buf.timestamp.tv_sec * INT64_C(1000000) + buf.timestamp.tv_usec;
377
    pkt->destruct = mmap_release_buffer;
378
    buf_descriptor = av_malloc(sizeof(struct buff_data));
379
    if (buf_descriptor == NULL) {
380
        /* Something went wrong... Since av_malloc() failed, we cannot even
381
         * allocate a buffer for memcopying into it
382
         */
383
        av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
384
        res = ioctl (s->fd, VIDIOC_QBUF, &buf);
385

    
386
        return -1;
387
    }
388
    buf_descriptor->fd = s->fd;
389
    buf_descriptor->index = buf.index;
390
    pkt->priv = buf_descriptor;
391

    
392
    return s->buf_len[buf.index];
393
}
394

    
395
static int read_frame(AVFormatContext *ctx, AVPacket *pkt)
396
{
397
    return -1;
398
}
399

    
400
static int mmap_start(AVFormatContext *ctx)
401
{
402
    struct video_data *s = ctx->priv_data;
403
    enum v4l2_buf_type type;
404
    int i, res;
405

    
406
    for (i = 0; i < s->buffers; i++) {
407
        struct v4l2_buffer buf;
408

    
409
        memset(&buf, 0, sizeof(struct v4l2_buffer));
410
        buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
411
        buf.memory = V4L2_MEMORY_MMAP;
412
        buf.index  = i;
413

    
414
        res = ioctl (s->fd, VIDIOC_QBUF, &buf);
415
        if (res < 0) {
416
            av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", strerror(errno));
417

    
418
            return -1;
419
        }
420
    }
421

    
422
    type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
423
    res = ioctl (s->fd, VIDIOC_STREAMON, &type);
424
    if (res < 0) {
425
        av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n", strerror(errno));
426

    
427
        return -1;
428
    }
429

    
430
    return 0;
431
}
432

    
433
static void mmap_close(struct video_data *s)
434
{
435
    enum v4l2_buf_type type;
436
    int i;
437

    
438
    type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
439
    /* We do not check for the result, because we could
440
     * not do anything about it anyway...
441
     */
442
    ioctl(s->fd, VIDIOC_STREAMOFF, &type);
443
    for (i = 0; i < s->buffers; i++) {
444
        munmap(s->buf_start[i], s->buf_len[i]);
445
    }
446
    av_free(s->buf_start);
447
    av_free(s->buf_len);
448
}
449

    
450
static int v4l2_set_parameters( AVFormatContext *s1, AVFormatParameters *ap )
451
{
452
    struct video_data *s = s1->priv_data;
453
    struct v4l2_input input;
454
    struct v4l2_standard standard;
455
    int i;
456

    
457
    if(ap->channel>=0) {
458
        /* set tv video input */
459
        memset (&input, 0, sizeof (input));
460
        input.index = ap->channel;
461
        if(ioctl (s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
462
            av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl enum input failed:\n");
463
            return AVERROR(EIO);
464
        }
465

    
466
        av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set input_id: %d, input: %s\n",
467
               ap->channel, input.name);
468
        if(ioctl (s->fd, VIDIOC_S_INPUT, &input.index) < 0 ) {
469
            av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set input(%d) failed\n",
470
                   ap->channel);
471
            return AVERROR(EIO);
472
        }
473
    }
474

    
475
    if(ap->standard) {
476
        av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s\n",
477
               ap->standard );
478
        /* set tv standard */
479
        memset (&standard, 0, sizeof (standard));
480
        for(i=0;;i++) {
481
            standard.index = i;
482
            if (ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
483
                av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set standard(%s) failed\n",
484
                       ap->standard);
485
                return AVERROR(EIO);
486
            }
487

    
488
            if(!strcasecmp(standard.name, ap->standard)) {
489
                break;
490
            }
491
        }
492

    
493
        av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s, id: %"PRIu64"\n",
494
               ap->standard, standard.id);
495
        if (ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
496
            av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set standard(%s) failed\n",
497
                   ap->standard);
498
            return AVERROR(EIO);
499
        }
500
    }
501

    
502
    return 0;
503
}
504

    
505
static int v4l2_read_header(AVFormatContext *s1, AVFormatParameters *ap)
506
{
507
    struct video_data *s = s1->priv_data;
508
    AVStream *st;
509
    int width, height;
510
    int res;
511
    uint32_t desired_format, capabilities;
512

    
513
    if (ap->width <= 0 || ap->height <= 0) {
514
        av_log(s1, AV_LOG_ERROR, "Wrong size (%dx%d)\n", ap->width, ap->height);
515
        return -1;
516
    }
517

    
518
    width = ap->width;
519
    height = ap->height;
520

    
521
    if(avcodec_check_dimensions(s1, ap->width, ap->height) < 0)
522
        return -1;
523

    
524
    st = av_new_stream(s1, 0);
525
    if (!st) {
526
        return AVERROR(ENOMEM);
527
    }
528
    av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
529

    
530
    s->width = width;
531
    s->height = height;
532

    
533
    capabilities = 0;
534
    s->fd = device_open(s1, &capabilities);
535
    if (s->fd < 0) {
536
        return AVERROR(EIO);
537
    }
538
    av_log(s1, AV_LOG_INFO, "[%d]Capabilities: %x\n", s->fd, capabilities);
539

    
540
    desired_format = fmt_ff2v4l(ap->pix_fmt);
541
    if (desired_format == 0 || (device_init(s1, &width, &height, desired_format) < 0)) {
542
        int i, done;
543

    
544
        done = 0; i = 0;
545
        while (!done) {
546
            desired_format = fmt_conversion_table[i].v4l2_fmt;
547
            if (device_init(s1, &width, &height, desired_format) < 0) {
548
                desired_format = 0;
549
                i++;
550
            } else {
551
               done = 1;
552
            }
553
            if (i == FF_ARRAY_ELEMS(fmt_conversion_table)) {
554
               done = 1;
555
            }
556
        }
557
    }
558
    if (desired_format == 0) {
559
        av_log(s1, AV_LOG_ERROR, "Cannot find a proper format.\n");
560
        close(s->fd);
561

    
562
        return AVERROR(EIO);
563
    }
564
    s->frame_format = desired_format;
565

    
566
    if( v4l2_set_parameters( s1, ap ) < 0 )
567
        return AVERROR(EIO);
568

    
569
    st->codec->pix_fmt = fmt_v4l2ff(desired_format);
570
    s->frame_size = avpicture_get_size(st->codec->pix_fmt, width, height);
571
    if (capabilities & V4L2_CAP_STREAMING) {
572
        s->io_method = io_mmap;
573
        res = mmap_init(s1);
574
        if (res == 0) {
575
            res = mmap_start(s1);
576
        }
577
    } else {
578
        s->io_method = io_read;
579
        res = read_init(s1);
580
    }
581
    if (res < 0) {
582
        close(s->fd);
583

    
584
        return AVERROR(EIO);
585
    }
586
    s->top_field_first = first_field(s->fd);
587

    
588
    st->codec->codec_type = CODEC_TYPE_VIDEO;
589
    st->codec->codec_id = CODEC_ID_RAWVIDEO;
590
    st->codec->width = width;
591
    st->codec->height = height;
592
    st->codec->time_base.den = ap->time_base.den;
593
    st->codec->time_base.num = ap->time_base.num;
594
    st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;
595

    
596
    return 0;
597
}
598

    
599
static int v4l2_read_packet(AVFormatContext *s1, AVPacket *pkt)
600
{
601
    struct video_data *s = s1->priv_data;
602
    int res;
603

    
604
    if (s->io_method == io_mmap) {
605
        av_init_packet(pkt);
606
        res = mmap_read_frame(s1, pkt);
607
    } else if (s->io_method == io_read) {
608
        if (av_new_packet(pkt, s->frame_size) < 0)
609
            return AVERROR(EIO);
610

    
611
        res = read_frame(s1, pkt);
612
    } else {
613
        return AVERROR(EIO);
614
    }
615
    if (res < 0) {
616
        return res;
617
    }
618

    
619
    if (s1->streams[0]->codec->coded_frame) {
620
        s1->streams[0]->codec->coded_frame->interlaced_frame = 1;
621
        s1->streams[0]->codec->coded_frame->top_field_first = s->top_field_first;
622
    }
623

    
624
    return s->frame_size;
625
}
626

    
627
static int v4l2_read_close(AVFormatContext *s1)
628
{
629
    struct video_data *s = s1->priv_data;
630

    
631
    if (s->io_method == io_mmap) {
632
        mmap_close(s);
633
    }
634

    
635
    close(s->fd);
636
    return 0;
637
}
638

    
639
AVInputFormat v4l2_demuxer = {
640
    "video4linux2",
641
    NULL_IF_CONFIG_SMALL("Video4Linux2 device grab"),
642
    sizeof(struct video_data),
643
    NULL,
644
    v4l2_read_header,
645
    v4l2_read_packet,
646
    v4l2_read_close,
647
    .flags = AVFMT_NOFILE,
648
};