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ffmpeg / libavdevice / v4l2.c @ 92d04e76

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1
/*
2
 * Video4Linux2 grab interface
3
 * Copyright (c) 2000,2001 Fabrice Bellard.
4
 * Copyright (c) 2006 Luca Abeni.
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 *
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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
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 * 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
 */
29

    
30
#undef __STRICT_ANSI__ //workaround due to broken kernel headers
31
#include "config.h"
32
#include "libavformat/avformat.h"
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#include <unistd.h>
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#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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#include <asm/types.h>
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#include <linux/videodev2.h>
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#include <time.h>
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#include <strings.h>
42

    
43
static const int desired_video_buffers = 256;
44

    
45
enum io_method {
46
    io_read,
47
    io_mmap,
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    io_userptr
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};
50

    
51
struct video_data {
52
    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;
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    int frame_rate;
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    int frame_rate_base;
58
    int frame_size;
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    int top_field_first;
60

    
61
    int buffers;
62
    void **buf_start;
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    unsigned int *buf_len;
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};
65

    
66
struct buff_data {
67
    int index;
68
    int fd;
69
};
70

    
71
struct fmt_map {
72
    enum PixelFormat ff_fmt;
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    int32_t v4l2_fmt;
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};
75

    
76
static struct fmt_map fmt_conversion_table[] = {
77
    {
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        .ff_fmt = PIX_FMT_YUV420P,
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        .v4l2_fmt = V4L2_PIX_FMT_YUV420,
80
    },
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    {
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        .ff_fmt = PIX_FMT_YUV422P,
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        .v4l2_fmt = V4L2_PIX_FMT_YUV422P,
84
    },
85
    {
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        .ff_fmt = PIX_FMT_YUYV422,
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        .v4l2_fmt = V4L2_PIX_FMT_YUYV,
88
    },
89
    {
90
        .ff_fmt = PIX_FMT_UYVY422,
91
        .v4l2_fmt = V4L2_PIX_FMT_UYVY,
92
    },
93
    {
94
        .ff_fmt = PIX_FMT_YUV411P,
95
        .v4l2_fmt = V4L2_PIX_FMT_YUV411P,
96
    },
97
    {
98
        .ff_fmt = PIX_FMT_YUV410P,
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        .v4l2_fmt = V4L2_PIX_FMT_YUV410,
100
    },
101
    {
102
        .ff_fmt = PIX_FMT_RGB555,
103
        .v4l2_fmt = V4L2_PIX_FMT_RGB555,
104
    },
105
    {
106
        .ff_fmt = PIX_FMT_RGB565,
107
        .v4l2_fmt = V4L2_PIX_FMT_RGB565,
108
    },
109
    {
110
        .ff_fmt = PIX_FMT_BGR24,
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        .v4l2_fmt = V4L2_PIX_FMT_BGR24,
112
    },
113
    {
114
        .ff_fmt = PIX_FMT_RGB24,
115
        .v4l2_fmt = V4L2_PIX_FMT_RGB24,
116
    },
117
    {
118
        .ff_fmt = PIX_FMT_BGRA,
119
        .v4l2_fmt = V4L2_PIX_FMT_BGR32,
120
    },
121
    {
122
        .ff_fmt = PIX_FMT_GRAY8,
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        .v4l2_fmt = V4L2_PIX_FMT_GREY,
124
    },
125
};
126

    
127
static int device_open(AVFormatContext *ctx, uint32_t *capabilities)
128
{
129
    struct v4l2_capability cap;
130
    int fd;
131
    int res;
132
    int flags = O_RDWR;
133

    
134
    if (ctx->flags & AVFMT_FLAG_NONBLOCK) {
135
        flags |= O_NONBLOCK;
136
    }
137
    fd = open(ctx->filename, flags, 0);
138
    if (fd < 0) {
139
        av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s : %s\n",
140
                 ctx->filename, strerror(errno));
141

    
142
        return -1;
143
    }
144

    
145
    res = ioctl(fd, VIDIOC_QUERYCAP, &cap);
146
    // ENOIOCTLCMD definition only availble on __KERNEL__
147
    if (res < 0 && errno == 515)
148
    {
149
        av_log(ctx, AV_LOG_ERROR, "QUERYCAP not implemented, probably V4L device but not supporting V4L2\n");
150
        close(fd);
151

    
152
        return -1;
153
    }
154
    if (res < 0) {
155
        av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
156
                 strerror(errno));
157
        close(fd);
158

    
159
        return -1;
160
    }
161
    if ((cap.capabilities & V4L2_CAP_VIDEO_CAPTURE) == 0) {
162
        av_log(ctx, AV_LOG_ERROR, "Not a video capture device\n");
163
        close(fd);
164

    
165
        return -1;
166
    }
167
    *capabilities = cap.capabilities;
168

    
169
    return fd;
170
}
171

    
172
static int device_init(AVFormatContext *ctx, int *width, int *height, int pix_fmt)
173
{
174
    struct video_data *s = ctx->priv_data;
175
    int fd = s->fd;
176
    struct v4l2_format fmt;
177
    int res;
178

    
179
    memset(&fmt, 0, sizeof(struct v4l2_format));
180
    fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
181
    fmt.fmt.pix.width = *width;
182
    fmt.fmt.pix.height = *height;
183
    fmt.fmt.pix.pixelformat = pix_fmt;
184
    fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;
185
    res = ioctl(fd, VIDIOC_S_FMT, &fmt);
186
    if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {
187
        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);
188
        *width = fmt.fmt.pix.width;
189
        *height = fmt.fmt.pix.height;
190
    }
191

    
192
    return res;
193
}
194

    
195
static int first_field(int fd)
196
{
197
    int res;
198
    v4l2_std_id std;
199

    
200
    res = ioctl(fd, VIDIOC_G_STD, &std);
201
    if (res < 0) {
202
        return 0;
203
    }
204
    if (std & V4L2_STD_NTSC) {
205
        return 0;
206
    }
207

    
208
    return 1;
209
}
210

    
211
static uint32_t fmt_ff2v4l(enum PixelFormat pix_fmt)
212
{
213
    int i;
214

    
215
    for (i = 0; i < sizeof(fmt_conversion_table) / sizeof(struct fmt_map); i++) {
216
        if (fmt_conversion_table[i].ff_fmt == pix_fmt) {
217
            return fmt_conversion_table[i].v4l2_fmt;
218
        }
219
    }
220

    
221
    return 0;
222
}
223

    
224
static enum PixelFormat fmt_v4l2ff(uint32_t pix_fmt)
225
{
226
    int i;
227

    
228
    for (i = 0; i < sizeof(fmt_conversion_table) / sizeof(struct fmt_map); i++) {
229
        if (fmt_conversion_table[i].v4l2_fmt == pix_fmt) {
230
            return fmt_conversion_table[i].ff_fmt;
231
        }
232
    }
233

    
234
    return PIX_FMT_NONE;
235
}
236

    
237
static int mmap_init(AVFormatContext *ctx)
238
{
239
    struct video_data *s = ctx->priv_data;
240
    struct v4l2_requestbuffers req;
241
    int i, res;
242

    
243
    memset(&req, 0, sizeof(struct v4l2_requestbuffers));
244
    req.count = desired_video_buffers;
245
    req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
246
    req.memory = V4L2_MEMORY_MMAP;
247
    res = ioctl (s->fd, VIDIOC_REQBUFS, &req);
248
    if (res < 0) {
249
        if (errno == EINVAL) {
250
            av_log(ctx, AV_LOG_ERROR, "Device does not support mmap\n");
251
        } else {
252
            av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS)\n");
253
        }
254

    
255
        return -1;
256
    }
257

    
258
    if (req.count < 2) {
259
        av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");
260

    
261
        return -1;
262
    }
263
    s->buffers = req.count;
264
    s->buf_start = av_malloc(sizeof(void *) * s->buffers);
265
    if (s->buf_start == NULL) {
266
        av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
267

    
268
        return -1;
269
    }
270
    s->buf_len = av_malloc(sizeof(unsigned int) * s->buffers);
271
    if (s->buf_len == NULL) {
272
        av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
273
        av_free(s->buf_start);
274

    
275
        return -1;
276
    }
277

    
278
    for (i = 0; i < req.count; i++) {
279
        struct v4l2_buffer buf;
280

    
281
        memset(&buf, 0, sizeof(struct v4l2_buffer));
282
        buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
283
        buf.memory = V4L2_MEMORY_MMAP;
284
        buf.index = i;
285
        res = ioctl (s->fd, VIDIOC_QUERYBUF, &buf);
286
        if (res < 0) {
287
            av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF)\n");
288

    
289
            return -1;
290
        }
291

    
292
        s->buf_len[i] = buf.length;
293
        if (s->buf_len[i] < s->frame_size) {
294
            av_log(ctx, AV_LOG_ERROR, "Buffer len [%d] = %d != %d\n", i, s->buf_len[i], s->frame_size);
295

    
296
            return -1;
297
        }
298
        s->buf_start[i] = mmap (NULL, buf.length,
299
                        PROT_READ | PROT_WRITE, MAP_SHARED, s->fd, buf.m.offset);
300
        if (s->buf_start[i] == MAP_FAILED) {
301
            av_log(ctx, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
302

    
303
            return -1;
304
        }
305
    }
306

    
307
    return 0;
308
}
309

    
310
static int read_init(AVFormatContext *ctx)
311
{
312
    return -1;
313
}
314

    
315
static void mmap_release_buffer(AVPacket *pkt)
316
{
317
    struct v4l2_buffer buf;
318
    int res, fd;
319
    struct buff_data *buf_descriptor = pkt->priv;
320

    
321
    memset(&buf, 0, sizeof(struct v4l2_buffer));
322
    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
323
    buf.memory = V4L2_MEMORY_MMAP;
324
    buf.index = buf_descriptor->index;
325
    fd = buf_descriptor->fd;
326
    av_free(buf_descriptor);
327

    
328
    res = ioctl (fd, VIDIOC_QBUF, &buf);
329
    if (res < 0) {
330
        av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF)\n");
331
    }
332
    pkt->data = NULL;
333
    pkt->size = 0;
334
}
335

    
336
static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
337
{
338
    struct video_data *s = ctx->priv_data;
339
    struct v4l2_buffer buf;
340
    struct buff_data *buf_descriptor;
341
    int res;
342

    
343
    memset(&buf, 0, sizeof(struct v4l2_buffer));
344
    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
345
    buf.memory = V4L2_MEMORY_MMAP;
346

    
347
    /* FIXME: Some special treatment might be needed in case of loss of signal... */
348
    while ((res = ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 && (errno == EINTR));
349
    if (res < 0) {
350
        if (errno == EAGAIN) {
351
            pkt->size = 0;
352

    
353
            return AVERROR(EAGAIN);
354
        }
355
        av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n", strerror(errno));
356

    
357
        return -1;
358
    }
359
    assert (buf.index < s->buffers);
360
    if (buf.bytesused != s->frame_size) {
361
        av_log(ctx, AV_LOG_ERROR, "The v4l2 frame is %d bytes, but %d bytes are expected\n", buf.bytesused, s->frame_size);
362

    
363
        return -1;
364
    }
365

    
366
    /* Image is at s->buff_start[buf.index] */
367
    pkt->data= s->buf_start[buf.index];
368
    pkt->size = buf.bytesused;
369
    pkt->pts = buf.timestamp.tv_sec * INT64_C(1000000) + buf.timestamp.tv_usec;
370
    pkt->destruct = mmap_release_buffer;
371
    buf_descriptor = av_malloc(sizeof(struct buff_data));
372
    if (buf_descriptor == NULL) {
373
        /* Something went wrong... Since av_malloc() failed, we cannot even
374
         * allocate a buffer for memcopying into it
375
         */
376
        av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
377
        res = ioctl (s->fd, VIDIOC_QBUF, &buf);
378

    
379
        return -1;
380
    }
381
    buf_descriptor->fd = s->fd;
382
    buf_descriptor->index = buf.index;
383
    pkt->priv = buf_descriptor;
384

    
385
    return s->buf_len[buf.index];
386
}
387

    
388
static int read_frame(AVFormatContext *ctx, AVPacket *pkt)
389
{
390
    return -1;
391
}
392

    
393
static int mmap_start(AVFormatContext *ctx)
394
{
395
    struct video_data *s = ctx->priv_data;
396
    enum v4l2_buf_type type;
397
    int i, res;
398

    
399
    for (i = 0; i < s->buffers; i++) {
400
        struct v4l2_buffer buf;
401

    
402
        memset(&buf, 0, sizeof(struct v4l2_buffer));
403
        buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
404
        buf.memory = V4L2_MEMORY_MMAP;
405
        buf.index  = i;
406

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

    
411
            return -1;
412
        }
413
    }
414

    
415
    type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
416
    res = ioctl (s->fd, VIDIOC_STREAMON, &type);
417
    if (res < 0) {
418
        av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n", strerror(errno));
419

    
420
        return -1;
421
    }
422

    
423
    return 0;
424
}
425

    
426
static void mmap_close(struct video_data *s)
427
{
428
    enum v4l2_buf_type type;
429
    int i;
430

    
431
    type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
432
    /* We do not check for the result, because we could
433
     * not do anything about it anyway...
434
     */
435
    ioctl(s->fd, VIDIOC_STREAMOFF, &type);
436
    for (i = 0; i < s->buffers; i++) {
437
        munmap(s->buf_start[i], s->buf_len[i]);
438
    }
439
    av_free(s->buf_start);
440
    av_free(s->buf_len);
441
}
442

    
443
static int v4l2_set_parameters( AVFormatContext *s1, AVFormatParameters *ap )
444
{
445
    struct video_data *s = s1->priv_data;
446
    struct v4l2_input input;
447
    struct v4l2_standard standard;
448
    int i;
449

    
450
    if(ap->channel>=0) {
451
        /* set tv video input */
452
        memset (&input, 0, sizeof (input));
453
        input.index = ap->channel;
454
        if(ioctl (s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
455
            av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl enum input failed:\n");
456
            return AVERROR(EIO);
457
        }
458

    
459
        av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set input_id: %d, input: %s\n",
460
               ap->channel, input.name);
461
        if(ioctl (s->fd, VIDIOC_S_INPUT, &input.index) < 0 ) {
462
            av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set input(%d) failed\n",
463
                   ap->channel);
464
            return AVERROR(EIO);
465
        }
466
    }
467

    
468
    if(ap->standard) {
469
        av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s\n",
470
               ap->standard );
471
        /* set tv standard */
472
        memset (&standard, 0, sizeof (standard));
473
        for(i=0;;i++) {
474
            standard.index = i;
475
            if (ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
476
                av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set standard(%s) failed\n",
477
                       ap->standard);
478
                return AVERROR(EIO);
479
            }
480

    
481
            if(!strcasecmp(standard.name, ap->standard)) {
482
                break;
483
            }
484
        }
485

    
486
        av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s, id: %"PRIu64"\n",
487
               ap->standard, standard.id);
488
        if (ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
489
            av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set standard(%s) failed\n",
490
                   ap->standard);
491
            return AVERROR(EIO);
492
        }
493
    }
494

    
495
    return 0;
496
}
497

    
498
static int v4l2_read_header(AVFormatContext *s1, AVFormatParameters *ap)
499
{
500
    struct video_data *s = s1->priv_data;
501
    AVStream *st;
502
    int width, height;
503
    int res, frame_rate, frame_rate_base;
504
    uint32_t desired_format, capabilities;
505

    
506
    if (ap->width <= 0 || ap->height <= 0) {
507
        av_log(s1, AV_LOG_ERROR, "Wrong size (%dx%d)\n", ap->width, ap->height);
508
        return -1;
509
    }
510
    if (ap->time_base.den <= 0) {
511
        av_log(s1, AV_LOG_ERROR, "Wrong time base (%d)\n", ap->time_base.den);
512
        return -1;
513
    }
514

    
515
    width = ap->width;
516
    height = ap->height;
517
    frame_rate = ap->time_base.den;
518
    frame_rate_base = ap->time_base.num;
519

    
520
    if((unsigned)width > 32767 || (unsigned)height > 32767) {
521
        av_log(s1, AV_LOG_ERROR, "Wrong size (%dx%d)\n", width, height);
522

    
523
        return -1;
524
    }
525

    
526
    st = av_new_stream(s1, 0);
527
    if (!st) {
528
        return AVERROR(ENOMEM);
529
    }
530
    av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
531

    
532
    s->width = width;
533
    s->height = height;
534
    s->frame_rate      = frame_rate;
535
    s->frame_rate_base = frame_rate_base;
536

    
537
    capabilities = 0;
538
    s->fd = device_open(s1, &capabilities);
539
    if (s->fd < 0) {
540
        return AVERROR(EIO);
541
    }
542
    av_log(s1, AV_LOG_INFO, "[%d]Capabilities: %x\n", s->fd, capabilities);
543

    
544
    desired_format = fmt_ff2v4l(ap->pix_fmt);
545
    if (desired_format == 0 || (device_init(s1, &width, &height, desired_format) < 0)) {
546
        int i, done;
547

    
548
        done = 0; i = 0;
549
        while (!done) {
550
            desired_format = fmt_conversion_table[i].v4l2_fmt;
551
            if (device_init(s1, &width, &height, desired_format) < 0) {
552
                desired_format = 0;
553
                i++;
554
            } else {
555
               done = 1;
556
            }
557
            if (i == sizeof(fmt_conversion_table) / sizeof(struct fmt_map)) {
558
               done = 1;
559
            }
560
        }
561
    }
562
    if (desired_format == 0) {
563
        av_log(s1, AV_LOG_ERROR, "Cannot find a proper format.\n");
564
        close(s->fd);
565

    
566
        return AVERROR(EIO);
567
    }
568
    s->frame_format = desired_format;
569

    
570
    if( v4l2_set_parameters( s1, ap ) < 0 )
571
        return AVERROR(EIO);
572

    
573
    st->codec->pix_fmt = fmt_v4l2ff(desired_format);
574
    s->frame_size = avpicture_get_size(st->codec->pix_fmt, width, height);
575
    if (capabilities & V4L2_CAP_STREAMING) {
576
        s->io_method = io_mmap;
577
        res = mmap_init(s1);
578
        if (res == 0) {
579
            res = mmap_start(s1);
580
        }
581
    } else {
582
        s->io_method = io_read;
583
        res = read_init(s1);
584
    }
585
    if (res < 0) {
586
        close(s->fd);
587

    
588
        return AVERROR(EIO);
589
    }
590
    s->top_field_first = first_field(s->fd);
591

    
592
    st->codec->codec_type = CODEC_TYPE_VIDEO;
593
    st->codec->codec_id = CODEC_ID_RAWVIDEO;
594
    st->codec->width = width;
595
    st->codec->height = height;
596
    st->codec->time_base.den = frame_rate;
597
    st->codec->time_base.num = frame_rate_base;
598
    st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;
599

    
600
    return 0;
601
}
602

    
603
static int v4l2_read_packet(AVFormatContext *s1, AVPacket *pkt)
604
{
605
    struct video_data *s = s1->priv_data;
606
    int res;
607

    
608
    if (s->io_method == io_mmap) {
609
        av_init_packet(pkt);
610
        res = mmap_read_frame(s1, pkt);
611
    } else if (s->io_method == io_read) {
612
        if (av_new_packet(pkt, s->frame_size) < 0)
613
            return AVERROR(EIO);
614

    
615
        res = read_frame(s1, pkt);
616
    } else {
617
        return AVERROR(EIO);
618
    }
619
    if (res < 0) {
620
        return res;
621
    }
622

    
623
    if (s1->streams[0]->codec->coded_frame) {
624
        s1->streams[0]->codec->coded_frame->interlaced_frame = 1;
625
        s1->streams[0]->codec->coded_frame->top_field_first = s->top_field_first;
626
    }
627

    
628
    return s->frame_size;
629
}
630

    
631
static int v4l2_read_close(AVFormatContext *s1)
632
{
633
    struct video_data *s = s1->priv_data;
634

    
635
    if (s->io_method == io_mmap) {
636
        mmap_close(s);
637
    }
638

    
639
    close(s->fd);
640
    return 0;
641
}
642

    
643
AVInputFormat v4l2_demuxer = {
644
    "video4linux2",
645
    NULL_IF_CONFIG_SMALL("video grab"),
646
    sizeof(struct video_data),
647
    NULL,
648
    v4l2_read_header,
649
    v4l2_read_packet,
650
    v4l2_read_close,
651
    .flags = AVFMT_NOFILE,
652
};