Statistics
| Branch: | Revision:

ffmpeg / libavformat / v4l2.c @ af74c95a

History | View | Annotate | Download (16.7 KB)

1
/*
2
 * Video4Linux2 grab interface
3
 * Copyright (c) 2000,2001 Fabrice Bellard.
4
 * Copyright (c) 2006 Luca Abeni.
5
 *
6
 * Part of this file is based on the V4L2 video capture example
7
 * (http://v4l2spec.bytesex.org/v4l2spec/capture.c)
8
 *
9
 * 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
17
 * License as published by the Free Software Foundation; either
18
 * version 2.1 of the License, or (at your option) any later version.
19
 *
20
 * 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
23
 * Lesser General Public License for more details.
24
 *
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
#include "avformat.h"
30
#include <unistd.h>
31
#include <fcntl.h>
32
#include <sys/ioctl.h>
33
#include <sys/mman.h>
34
#include <sys/time.h>
35
#include <asm/types.h>
36
#include <linux/videodev2.h>
37
#include <time.h>
38

    
39
static const int desired_video_buffers = 256;
40

    
41
enum io_method {
42
    io_read,
43
    io_mmap,
44
    io_userptr
45
};
46

    
47
struct video_data {
48
    int fd;
49
    int frame_format; /* V4L2_PIX_FMT_* */
50
    enum io_method io_method;
51
    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;
59
    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
    {
74
        .ff_fmt = PIX_FMT_YUV420P,
75
        .v4l2_fmt = V4L2_PIX_FMT_YUV420,
76
    },
77
    {
78
        .ff_fmt = PIX_FMT_YUV422P,
79
        .v4l2_fmt = V4L2_PIX_FMT_YUV422P,
80
    },
81
    {
82
        .ff_fmt = PIX_FMT_YUYV422,
83
        .v4l2_fmt = V4L2_PIX_FMT_YUYV,
84
    },
85
    {
86
        .ff_fmt = PIX_FMT_UYVY422,
87
        .v4l2_fmt = V4L2_PIX_FMT_UYVY,
88
    },
89
    {
90
        .ff_fmt = PIX_FMT_YUV411P,
91
        .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,
108
        .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
    int flags = O_RDWR;
123

    
124
    if (ctx->flags & AVFMT_FLAG_NONBLOCK) {
125
        flags |= O_NONBLOCK;
126
    }
127
    fd = open(ctx->filename, flags, 0);
128
    if (fd < 0) {
129
        av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s : %s\n",
130
                 ctx->filename, strerror(errno));
131

    
132
        return -1;
133
    }
134

    
135
    res = ioctl(fd, VIDIOC_QUERYCAP, &cap);
136
    // ENOIOCTLCMD definition only availble on __KERNEL__
137
    if (res < 0 && errno == 515)
138
    {
139
        av_log(ctx, AV_LOG_ERROR, "QUERYCAP not implemented, probably V4L device but not supporting V4L2\n");
140
        close(fd);
141

    
142
        return -1;
143
    }
144
    if (res < 0) {
145
        av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
146
                 strerror(errno));
147
        close(fd);
148

    
149
        return -1;
150
    }
151
    if ((cap.capabilities & V4L2_CAP_VIDEO_CAPTURE) == 0) {
152
        av_log(ctx, AV_LOG_ERROR, "Not a video capture device\n");
153
        close(fd);
154

    
155
        return -1;
156
    }
157
    *capabilities = cap.capabilities;
158

    
159
    return fd;
160
}
161

    
162
static int device_init(AVFormatContext *ctx, int *width, int *height, int pix_fmt)
163
{
164
    struct video_data *s = ctx->priv_data;
165
    int fd = s->fd;
166
    struct v4l2_format fmt;
167
    int res;
168

    
169
    memset(&fmt, 0, sizeof(struct v4l2_format));
170
    fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
171
    fmt.fmt.pix.width = *width;
172
    fmt.fmt.pix.height = *height;
173
    fmt.fmt.pix.pixelformat = pix_fmt;
174
    fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;
175
    res = ioctl(fd, VIDIOC_S_FMT, &fmt);
176
    if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {
177
        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);
178
        *width = fmt.fmt.pix.width;
179
        *height = fmt.fmt.pix.height;
180
    }
181

    
182
    return res;
183
}
184

    
185
static int first_field(int fd)
186
{
187
    int res;
188
    v4l2_std_id std;
189

    
190
    res = ioctl(fd, VIDIOC_G_STD, &std);
191
    if (res < 0) {
192
        return 0;
193
    }
194
    if (std & V4L2_STD_NTSC) {
195
        return 0;
196
    }
197

    
198
    return 1;
199
}
200

    
201
static uint32_t fmt_ff2v4l(enum PixelFormat pix_fmt)
202
{
203
    int i;
204

    
205
    for (i = 0; i < sizeof(fmt_conversion_table) / sizeof(struct fmt_map); i++) {
206
        if (fmt_conversion_table[i].ff_fmt == pix_fmt) {
207
            return fmt_conversion_table[i].v4l2_fmt;
208
        }
209
    }
210

    
211
    return 0;
212
}
213

    
214
static enum PixelFormat fmt_v4l2ff(uint32_t pix_fmt)
215
{
216
    int i;
217

    
218
    for (i = 0; i < sizeof(fmt_conversion_table) / sizeof(struct fmt_map); i++) {
219
        if (fmt_conversion_table[i].v4l2_fmt == pix_fmt) {
220
            return fmt_conversion_table[i].ff_fmt;
221
        }
222
    }
223

    
224
    return -1;
225
}
226

    
227
static int mmap_init(AVFormatContext *ctx)
228
{
229
    struct video_data *s = ctx->priv_data;
230
    struct v4l2_requestbuffers req;
231
    int i, res;
232

    
233
    memset(&req, 0, sizeof(struct v4l2_requestbuffers));
234
    req.count = desired_video_buffers;
235
    req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
236
    req.memory = V4L2_MEMORY_MMAP;
237
    res = ioctl (s->fd, VIDIOC_REQBUFS, &req);
238
    if (res < 0) {
239
        if (errno == EINVAL) {
240
            av_log(ctx, AV_LOG_ERROR, "Device does not support mmap\n");
241
        } else {
242
            av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS)\n");
243
        }
244

    
245
        return -1;
246
    }
247

    
248
    if (req.count < 2) {
249
        av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");
250

    
251
        return -1;
252
    }
253
    s->buffers = req.count;
254
    s->buf_start = av_malloc(sizeof(void *) * s->buffers);
255
    if (s->buf_start == NULL) {
256
        av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
257

    
258
        return -1;
259
    }
260
    s->buf_len = av_malloc(sizeof(unsigned int) * s->buffers);
261
    if (s->buf_len == NULL) {
262
        av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
263
        av_free(s->buf_start);
264

    
265
        return -1;
266
    }
267

    
268
    for (i = 0; i < req.count; i++) {
269
        struct v4l2_buffer buf;
270

    
271
        memset(&buf, 0, sizeof(struct v4l2_buffer));
272
        buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
273
        buf.memory = V4L2_MEMORY_MMAP;
274
        buf.index = i;
275
        res = ioctl (s->fd, VIDIOC_QUERYBUF, &buf);
276
        if (res < 0) {
277
            av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF)\n");
278

    
279
            return -1;
280
        }
281

    
282
        s->buf_len[i] = buf.length;
283
        if (s->buf_len[i] < s->frame_size) {
284
            av_log(ctx, AV_LOG_ERROR, "Buffer len [%d] = %d != %d\n", i, s->buf_len[i], s->frame_size);
285

    
286
            return -1;
287
        }
288
        s->buf_start[i] = mmap (NULL, buf.length,
289
                        PROT_READ | PROT_WRITE, MAP_SHARED, s->fd, buf.m.offset);
290
        if (s->buf_start[i] == MAP_FAILED) {
291
            av_log(ctx, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
292

    
293
            return -1;
294
        }
295
    }
296

    
297
    return 0;
298
}
299

    
300
static int read_init(AVFormatContext *ctx)
301
{
302
    return -1;
303
}
304

    
305
static void mmap_release_buffer(AVPacket *pkt)
306
{
307
    struct v4l2_buffer buf;
308
    int res, fd;
309
    struct buff_data *buf_descriptor = pkt->priv;
310

    
311
    memset(&buf, 0, sizeof(struct v4l2_buffer));
312
    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
313
    buf.memory = V4L2_MEMORY_MMAP;
314
    buf.index = buf_descriptor->index;
315
    fd = buf_descriptor->fd;
316
    av_free(buf_descriptor);
317

    
318
    res = ioctl (fd, VIDIOC_QBUF, &buf);
319
    if (res < 0) {
320
        av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF)\n");
321
    }
322
    pkt->data = NULL;
323
    pkt->size = 0;
324
}
325

    
326
static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
327
{
328
    struct video_data *s = ctx->priv_data;
329
    struct v4l2_buffer buf;
330
    struct buff_data *buf_descriptor;
331
    int res;
332

    
333
    memset(&buf, 0, sizeof(struct v4l2_buffer));
334
    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
335
    buf.memory = V4L2_MEMORY_MMAP;
336

    
337
    /* FIXME: Some special treatment might be needed in case of loss of signal... */
338
    while ((res = ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 && (errno == EINTR));
339
    if (res < 0) {
340
        if (errno == EAGAIN) {
341
            pkt->size = 0;
342

    
343
            return AVERROR(EAGAIN);
344
        }
345
        av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n", strerror(errno));
346

    
347
        return -1;
348
    }
349
    assert (buf.index < s->buffers);
350
    if (buf.bytesused != s->frame_size) {
351
        av_log(ctx, AV_LOG_ERROR, "The v4l2 frame is %d bytes, but %d bytes are expected\n", buf.bytesused, s->frame_size);
352

    
353
        return -1;
354
    }
355

    
356
    /* Image is at s->buff_start[buf.index] */
357
    pkt->data= s->buf_start[buf.index];
358
    pkt->size = buf.bytesused;
359
    pkt->pts = buf.timestamp.tv_sec * INT64_C(1000000) + buf.timestamp.tv_usec;
360
    pkt->destruct = mmap_release_buffer;
361
    buf_descriptor = av_malloc(sizeof(struct buff_data));
362
    if (buf_descriptor == NULL) {
363
        /* Something went wrong... Since av_malloc() failed, we cannot even
364
         * allocate a buffer for memcopying into it
365
         */
366
        av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
367
        res = ioctl (s->fd, VIDIOC_QBUF, &buf);
368

    
369
        return -1;
370
    }
371
    buf_descriptor->fd = s->fd;
372
    buf_descriptor->index = buf.index;
373
    pkt->priv = buf_descriptor;
374

    
375
    return s->buf_len[buf.index];
376
}
377

    
378
static int read_frame(AVFormatContext *ctx, AVPacket *pkt)
379
{
380
    return -1;
381
}
382

    
383
static int mmap_start(AVFormatContext *ctx)
384
{
385
    struct video_data *s = ctx->priv_data;
386
    enum v4l2_buf_type type;
387
    int i, res;
388

    
389
    for (i = 0; i < s->buffers; i++) {
390
        struct v4l2_buffer buf;
391

    
392
        memset(&buf, 0, sizeof(struct v4l2_buffer));
393
        buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
394
        buf.memory = V4L2_MEMORY_MMAP;
395
        buf.index  = i;
396

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

    
401
            return -1;
402
        }
403
    }
404

    
405
    type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
406
    res = ioctl (s->fd, VIDIOC_STREAMON, &type);
407
    if (res < 0) {
408
        av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n", strerror(errno));
409

    
410
        return -1;
411
    }
412

    
413
    return 0;
414
}
415

    
416
static void mmap_close(struct video_data *s)
417
{
418
    enum v4l2_buf_type type;
419
    int i;
420

    
421
    type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
422
    /* We do not check for the result, because we could
423
     * not do anything about it anyway...
424
     */
425
    ioctl(s->fd, VIDIOC_STREAMOFF, &type);
426
    for (i = 0; i < s->buffers; i++) {
427
        munmap(s->buf_start[i], s->buf_len[i]);
428
    }
429
    av_free(s->buf_start);
430
    av_free(s->buf_len);
431
}
432

    
433
static int v4l2_set_parameters( AVFormatContext *s1, AVFormatParameters *ap )
434
{
435
    struct video_data *s = s1->priv_data;
436
    struct v4l2_input input;
437
    struct v4l2_standard standard;
438
    int i;
439

    
440
    if(ap->channel>=0) {
441
        /* set tv video input */
442
        memset (&input, 0, sizeof (input));
443
        input.index = ap->channel;
444
        if(ioctl (s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
445
            av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl enum input failed:\n");
446
            return AVERROR(EIO);
447
        }
448

    
449
        av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set input_id: %d, input: %s\n",
450
               ap->channel, input.name);
451
        if(ioctl (s->fd, VIDIOC_S_INPUT, &input.index) < 0 ) {
452
            av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set input(%d) failed\n",
453
                   ap->channel);
454
            return AVERROR(EIO);
455
        }
456
    }
457

    
458
    if(ap->standard) {
459
        av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s\n",
460
               ap->standard );
461
        /* set tv standard */
462
        memset (&standard, 0, sizeof (standard));
463
        for(i=0;;i++) {
464
            standard.index = i;
465
            if (ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
466
                av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set standard(%s) failed\n",
467
                       ap->standard);
468
                return AVERROR(EIO);
469
            }
470

    
471
            if(!strcasecmp(standard.name, ap->standard)) {
472
                break;
473
            }
474
        }
475

    
476
        av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s, id: %"PRIu64"\n",
477
               ap->standard, standard.id);
478
        if (ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
479
            av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set standard(%s) failed\n",
480
                   ap->standard);
481
            return AVERROR(EIO);
482
        }
483
    }
484

    
485
    return 0;
486
}
487

    
488
static int v4l2_read_header(AVFormatContext *s1, AVFormatParameters *ap)
489
{
490
    struct video_data *s = s1->priv_data;
491
    AVStream *st;
492
    int width, height;
493
    int res, frame_rate, frame_rate_base;
494
    uint32_t desired_format, capabilities;
495

    
496
    if (ap->width <= 0 || ap->height <= 0 || ap->time_base.den <= 0) {
497
        av_log(s1, AV_LOG_ERROR, "Missing/Wrong parameters\n");
498

    
499
        return -1;
500
    }
501

    
502
    width = ap->width;
503
    height = ap->height;
504
    frame_rate = ap->time_base.den;
505
    frame_rate_base = ap->time_base.num;
506

    
507
    if((unsigned)width > 32767 || (unsigned)height > 32767) {
508
        av_log(s1, AV_LOG_ERROR, "Wrong size %dx%d\n", width, height);
509

    
510
        return -1;
511
    }
512

    
513
    st = av_new_stream(s1, 0);
514
    if (!st) {
515
        return AVERROR(ENOMEM);
516
    }
517
    av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
518

    
519
    s->width = width;
520
    s->height = height;
521
    s->frame_rate      = frame_rate;
522
    s->frame_rate_base = frame_rate_base;
523

    
524
    capabilities = 0;
525
    s->fd = device_open(s1, &capabilities);
526
    if (s->fd < 0) {
527
        av_free(st);
528

    
529
        return AVERROR(EIO);
530
    }
531
    av_log(s1, AV_LOG_INFO, "[%d]Capabilities: %x\n", s->fd, capabilities);
532

    
533
    desired_format = fmt_ff2v4l(ap->pix_fmt);
534
    if (desired_format == 0 || (device_init(s1, &width, &height, desired_format) < 0)) {
535
        int i, done;
536

    
537
        done = 0; i = 0;
538
        while (!done) {
539
            desired_format = fmt_conversion_table[i].v4l2_fmt;
540
            if (device_init(s1, &width, &height, desired_format) < 0) {
541
                desired_format = 0;
542
                i++;
543
            } else {
544
               done = 1;
545
            }
546
            if (i == sizeof(fmt_conversion_table) / sizeof(struct fmt_map)) {
547
               done = 1;
548
            }
549
        }
550
    }
551
    if (desired_format == 0) {
552
        av_log(s1, AV_LOG_ERROR, "Cannot find a proper format.\n");
553
        close(s->fd);
554
        av_free(st);
555

    
556
        return AVERROR(EIO);
557
    }
558
    s->frame_format = desired_format;
559

    
560
    if( v4l2_set_parameters( s1, ap ) < 0 )
561
        return AVERROR(EIO);
562

    
563
    st->codec->pix_fmt = fmt_v4l2ff(desired_format);
564
    s->frame_size = avpicture_get_size(st->codec->pix_fmt, width, height);
565
    if (capabilities & V4L2_CAP_STREAMING) {
566
        s->io_method = io_mmap;
567
        res = mmap_init(s1);
568
        if (res == 0) {
569
            res = mmap_start(s1);
570
        }
571
    } else {
572
        s->io_method = io_read;
573
        res = read_init(s1);
574
    }
575
    if (res < 0) {
576
        close(s->fd);
577
        av_free(st);
578

    
579
        return AVERROR(EIO);
580
    }
581
    s->top_field_first = first_field(s->fd);
582

    
583
    st->codec->codec_type = CODEC_TYPE_VIDEO;
584
    st->codec->codec_id = CODEC_ID_RAWVIDEO;
585
    st->codec->width = width;
586
    st->codec->height = height;
587
    st->codec->time_base.den = frame_rate;
588
    st->codec->time_base.num = frame_rate_base;
589
    st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;
590

    
591
    return 0;
592
}
593

    
594
static int v4l2_read_packet(AVFormatContext *s1, AVPacket *pkt)
595
{
596
    struct video_data *s = s1->priv_data;
597
    int res;
598

    
599
    if (s->io_method == io_mmap) {
600
        av_init_packet(pkt);
601
        res = mmap_read_frame(s1, pkt);
602
    } else if (s->io_method == io_read) {
603
        if (av_new_packet(pkt, s->frame_size) < 0)
604
            return AVERROR(EIO);
605

    
606
        res = read_frame(s1, pkt);
607
    } else {
608
        return AVERROR(EIO);
609
    }
610
    if (res < 0) {
611
        return AVERROR(EIO);
612
    }
613

    
614
    if (s1->streams[0]->codec->coded_frame) {
615
        s1->streams[0]->codec->coded_frame->interlaced_frame = 1;
616
        s1->streams[0]->codec->coded_frame->top_field_first = s->top_field_first;
617
    }
618

    
619
    return s->frame_size;
620
}
621

    
622
static int v4l2_read_close(AVFormatContext *s1)
623
{
624
    struct video_data *s = s1->priv_data;
625

    
626
    if (s->io_method == io_mmap) {
627
        mmap_close(s);
628
    }
629

    
630
    close(s->fd);
631
    return 0;
632
}
633

    
634
AVInputFormat v4l2_demuxer = {
635
    "video4linux2",
636
    "video grab",
637
    sizeof(struct video_data),
638
    NULL,
639
    v4l2_read_header,
640
    v4l2_read_packet,
641
    v4l2_read_close,
642
    .flags = AVFMT_NOFILE,
643
};