GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavdevice/v4l2.c Lines: 3 541 0.6 %
Date: 2020-10-23 17:01:47 Branches: 1 301 0.3 %

Line Branch Exec Source
1
/*
2
 * Copyright (c) 2000,2001 Fabrice Bellard
3
 * Copyright (c) 2006 Luca Abeni
4
 *
5
 * This file is part of FFmpeg.
6
 *
7
 * FFmpeg is free software; you can redistribute it and/or
8
 * modify it under the terms of the GNU Lesser General Public
9
 * License as published by the Free Software Foundation; either
10
 * version 2.1 of the License, or (at your option) any later version.
11
 *
12
 * FFmpeg is distributed in the hope that it will be useful,
13
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15
 * Lesser General Public License for more details.
16
 *
17
 * You should have received a copy of the GNU Lesser General Public
18
 * License along with FFmpeg; if not, write to the Free Software
19
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20
 */
21
22
/**
23
 * @file
24
 * Video4Linux2 grab interface
25
 *
26
 * Part of this file is based on the V4L2 video capture example
27
 * (http://linuxtv.org/downloads/v4l-dvb-apis/capture-example.html)
28
 *
29
 * Thanks to Michael Niedermayer for providing the mapping between
30
 * V4L2_PIX_FMT_* and AV_PIX_FMT_*
31
 */
32
33
#include <stdatomic.h>
34
35
#include "v4l2-common.h"
36
#include <dirent.h>
37
38
#if CONFIG_LIBV4L2
39
#include <libv4l2.h>
40
#endif
41
42
static const int desired_video_buffers = 256;
43
44
#define V4L_ALLFORMATS  3
45
#define V4L_RAWFORMATS  1
46
#define V4L_COMPFORMATS 2
47
48
/**
49
 * Return timestamps to the user exactly as returned by the kernel
50
 */
51
#define V4L_TS_DEFAULT  0
52
/**
53
 * Autodetect the kind of timestamps returned by the kernel and convert to
54
 * absolute (wall clock) timestamps.
55
 */
56
#define V4L_TS_ABS      1
57
/**
58
 * Assume kernel timestamps are from the monotonic clock and convert to
59
 * absolute timestamps.
60
 */
61
#define V4L_TS_MONO2ABS 2
62
63
/**
64
 * Once the kind of timestamps returned by the kernel have been detected,
65
 * the value of the timefilter (NULL or not) determines whether a conversion
66
 * takes place.
67
 */
68
#define V4L_TS_CONVERT_READY V4L_TS_DEFAULT
69
70
struct video_data {
71
    AVClass *class;
72
    int fd;
73
    int pixelformat; /* V4L2_PIX_FMT_* */
74
    int width, height;
75
    int frame_size;
76
    int interlaced;
77
    int top_field_first;
78
    int ts_mode;
79
    TimeFilter *timefilter;
80
    int64_t last_time_m;
81
82
    int buffers;
83
    atomic_int buffers_queued;
84
    void **buf_start;
85
    unsigned int *buf_len;
86
    char *standard;
87
    v4l2_std_id std_id;
88
    int channel;
89
    char *pixel_format; /**< Set by a private option. */
90
    int list_format;    /**< Set by a private option. */
91
    int list_standard;  /**< Set by a private option. */
92
    char *framerate;    /**< Set by a private option. */
93
94
    int use_libv4l2;
95
    int (*open_f)(const char *file, int oflag, ...);
96
    int (*close_f)(int fd);
97
    int (*dup_f)(int fd);
98
#ifdef __GLIBC__
99
    int (*ioctl_f)(int fd, unsigned long int request, ...);
100
#else
101
    int (*ioctl_f)(int fd, int request, ...);
102
#endif
103
    ssize_t (*read_f)(int fd, void *buffer, size_t n);
104
    void *(*mmap_f)(void *start, size_t length, int prot, int flags, int fd, int64_t offset);
105
    int (*munmap_f)(void *_start, size_t length);
106
};
107
108
struct buff_data {
109
    struct video_data *s;
110
    int index;
111
};
112
113
static int device_open(AVFormatContext *ctx, const char* device_path)
114
{
115
    struct video_data *s = ctx->priv_data;
116
    struct v4l2_capability cap;
117
    int fd;
118
    int err;
119
    int flags = O_RDWR;
120
121
#define SET_WRAPPERS(prefix) do {       \
122
    s->open_f   = prefix ## open;       \
123
    s->close_f  = prefix ## close;      \
124
    s->dup_f    = prefix ## dup;        \
125
    s->ioctl_f  = prefix ## ioctl;      \
126
    s->read_f   = prefix ## read;       \
127
    s->mmap_f   = prefix ## mmap;       \
128
    s->munmap_f = prefix ## munmap;     \
129
} while (0)
130
131
    if (s->use_libv4l2) {
132
#if CONFIG_LIBV4L2
133
        SET_WRAPPERS(v4l2_);
134
#else
135
        av_log(ctx, AV_LOG_ERROR, "libavdevice is not built with libv4l2 support.\n");
136
        return AVERROR(EINVAL);
137
#endif
138
    } else {
139
        SET_WRAPPERS();
140
    }
141
142
#define v4l2_open   s->open_f
143
#define v4l2_close  s->close_f
144
#define v4l2_dup    s->dup_f
145
#define v4l2_ioctl  s->ioctl_f
146
#define v4l2_read   s->read_f
147
#define v4l2_mmap   s->mmap_f
148
#define v4l2_munmap s->munmap_f
149
150
    if (ctx->flags & AVFMT_FLAG_NONBLOCK) {
151
        flags |= O_NONBLOCK;
152
    }
153
154
    fd = v4l2_open(device_path, flags, 0);
155
    if (fd < 0) {
156
        err = AVERROR(errno);
157
        av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s: %s\n",
158
               device_path, av_err2str(err));
159
        return err;
160
    }
161
162
    if (v4l2_ioctl(fd, VIDIOC_QUERYCAP, &cap) < 0) {
163
        err = AVERROR(errno);
164
        av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
165
               av_err2str(err));
166
        goto fail;
167
    }
168
169
    av_log(ctx, AV_LOG_VERBOSE, "fd:%d capabilities:%x\n",
170
           fd, cap.capabilities);
171
172
    if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {
173
        av_log(ctx, AV_LOG_ERROR, "Not a video capture device.\n");
174
        err = AVERROR(ENODEV);
175
        goto fail;
176
    }
177
178
    if (!(cap.capabilities & V4L2_CAP_STREAMING)) {
179
        av_log(ctx, AV_LOG_ERROR,
180
               "The device does not support the streaming I/O method.\n");
181
        err = AVERROR(ENOSYS);
182
        goto fail;
183
    }
184
185
    return fd;
186
187
fail:
188
    v4l2_close(fd);
189
    return err;
190
}
191
192
static int device_init(AVFormatContext *ctx, int *width, int *height,
193
                       uint32_t pixelformat)
194
{
195
    struct video_data *s = ctx->priv_data;
196
    struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
197
    int res = 0;
198
199
    fmt.fmt.pix.width = *width;
200
    fmt.fmt.pix.height = *height;
201
    fmt.fmt.pix.pixelformat = pixelformat;
202
    fmt.fmt.pix.field = V4L2_FIELD_ANY;
203
204
    /* Some drivers will fail and return EINVAL when the pixelformat
205
       is not supported (even if type field is valid and supported) */
206
    if (v4l2_ioctl(s->fd, VIDIOC_S_FMT, &fmt) < 0)
207
        res = AVERROR(errno);
208
209
    if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {
210
        av_log(ctx, AV_LOG_INFO,
211
               "The V4L2 driver changed the video from %dx%d to %dx%d\n",
212
               *width, *height, fmt.fmt.pix.width, fmt.fmt.pix.height);
213
        *width = fmt.fmt.pix.width;
214
        *height = fmt.fmt.pix.height;
215
    }
216
217
    if (pixelformat != fmt.fmt.pix.pixelformat) {
218
        av_log(ctx, AV_LOG_DEBUG,
219
               "The V4L2 driver changed the pixel format "
220
               "from 0x%08X to 0x%08X\n",
221
               pixelformat, fmt.fmt.pix.pixelformat);
222
        res = AVERROR(EINVAL);
223
    }
224
225
    if (fmt.fmt.pix.field == V4L2_FIELD_INTERLACED) {
226
        av_log(ctx, AV_LOG_DEBUG,
227
               "The V4L2 driver is using the interlaced mode\n");
228
        s->interlaced = 1;
229
    }
230
231
    return res;
232
}
233
234
static int first_field(const struct video_data *s)
235
{
236
    int res;
237
    v4l2_std_id std;
238
239
    res = v4l2_ioctl(s->fd, VIDIOC_G_STD, &std);
240
    if (res < 0)
241
        return 0;
242
    if (std & V4L2_STD_NTSC)
243
        return 0;
244
245
    return 1;
246
}
247
248
#if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
249
static void list_framesizes(AVFormatContext *ctx, uint32_t pixelformat)
250
{
251
    const struct video_data *s = ctx->priv_data;
252
    struct v4l2_frmsizeenum vfse = { .pixel_format = pixelformat };
253
254
    while(!v4l2_ioctl(s->fd, VIDIOC_ENUM_FRAMESIZES, &vfse)) {
255
        switch (vfse.type) {
256
        case V4L2_FRMSIZE_TYPE_DISCRETE:
257
            av_log(ctx, AV_LOG_INFO, " %ux%u",
258
                   vfse.discrete.width, vfse.discrete.height);
259
        break;
260
        case V4L2_FRMSIZE_TYPE_CONTINUOUS:
261
        case V4L2_FRMSIZE_TYPE_STEPWISE:
262
            av_log(ctx, AV_LOG_INFO, " {%u-%u, %u}x{%u-%u, %u}",
263
                   vfse.stepwise.min_width,
264
                   vfse.stepwise.max_width,
265
                   vfse.stepwise.step_width,
266
                   vfse.stepwise.min_height,
267
                   vfse.stepwise.max_height,
268
                   vfse.stepwise.step_height);
269
        }
270
        vfse.index++;
271
    }
272
}
273
#endif
274
275
static void list_formats(AVFormatContext *ctx, int type)
276
{
277
    const struct video_data *s = ctx->priv_data;
278
    struct v4l2_fmtdesc vfd = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
279
280
    while(!v4l2_ioctl(s->fd, VIDIOC_ENUM_FMT, &vfd)) {
281
        enum AVCodecID codec_id = ff_fmt_v4l2codec(vfd.pixelformat);
282
        enum AVPixelFormat pix_fmt = ff_fmt_v4l2ff(vfd.pixelformat, codec_id);
283
284
        vfd.index++;
285
286
        if (!(vfd.flags & V4L2_FMT_FLAG_COMPRESSED) &&
287
            type & V4L_RAWFORMATS) {
288
            const char *fmt_name = av_get_pix_fmt_name(pix_fmt);
289
            av_log(ctx, AV_LOG_INFO, "Raw       : %11s : %20s :",
290
                   fmt_name ? fmt_name : "Unsupported",
291
                   vfd.description);
292
        } else if (vfd.flags & V4L2_FMT_FLAG_COMPRESSED &&
293
                   type & V4L_COMPFORMATS) {
294
            const AVCodecDescriptor *desc = avcodec_descriptor_get(codec_id);
295
            av_log(ctx, AV_LOG_INFO, "Compressed: %11s : %20s :",
296
                   desc ? desc->name : "Unsupported",
297
                   vfd.description);
298
        } else {
299
            continue;
300
        }
301
302
#ifdef V4L2_FMT_FLAG_EMULATED
303
        if (vfd.flags & V4L2_FMT_FLAG_EMULATED)
304
            av_log(ctx, AV_LOG_INFO, " Emulated :");
305
#endif
306
#if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
307
        list_framesizes(ctx, vfd.pixelformat);
308
#endif
309
        av_log(ctx, AV_LOG_INFO, "\n");
310
    }
311
}
312
313
static void list_standards(AVFormatContext *ctx)
314
{
315
    int ret;
316
    struct video_data *s = ctx->priv_data;
317
    struct v4l2_standard standard;
318
319
    if (s->std_id == 0)
320
        return;
321
322
    for (standard.index = 0; ; standard.index++) {
323
        if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
324
            ret = AVERROR(errno);
325
            if (ret == AVERROR(EINVAL)) {
326
                break;
327
            } else {
328
                av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMSTD): %s\n", av_err2str(ret));
329
                return;
330
            }
331
        }
332
        av_log(ctx, AV_LOG_INFO, "%2d, %16"PRIx64", %s\n",
333
               standard.index, (uint64_t)standard.id, standard.name);
334
    }
335
}
336
337
static int mmap_init(AVFormatContext *ctx)
338
{
339
    int i, res;
340
    struct video_data *s = ctx->priv_data;
341
    struct v4l2_requestbuffers req = {
342
        .type   = V4L2_BUF_TYPE_VIDEO_CAPTURE,
343
        .count  = desired_video_buffers,
344
        .memory = V4L2_MEMORY_MMAP
345
    };
346
347
    if (v4l2_ioctl(s->fd, VIDIOC_REQBUFS, &req) < 0) {
348
        res = AVERROR(errno);
349
        av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS): %s\n", av_err2str(res));
350
        return res;
351
    }
352
353
    if (req.count < 2) {
354
        av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");
355
        return AVERROR(ENOMEM);
356
    }
357
    s->buffers = req.count;
358
    s->buf_start = av_malloc_array(s->buffers, sizeof(void *));
359
    if (!s->buf_start) {
360
        av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
361
        return AVERROR(ENOMEM);
362
    }
363
    s->buf_len = av_malloc_array(s->buffers, sizeof(unsigned int));
364
    if (!s->buf_len) {
365
        av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
366
        av_freep(&s->buf_start);
367
        return AVERROR(ENOMEM);
368
    }
369
370
    for (i = 0; i < req.count; i++) {
371
        struct v4l2_buffer buf = {
372
            .type   = V4L2_BUF_TYPE_VIDEO_CAPTURE,
373
            .index  = i,
374
            .memory = V4L2_MEMORY_MMAP
375
        };
376
        if (v4l2_ioctl(s->fd, VIDIOC_QUERYBUF, &buf) < 0) {
377
            res = AVERROR(errno);
378
            av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF): %s\n", av_err2str(res));
379
            return res;
380
        }
381
382
        s->buf_len[i] = buf.length;
383
        if (s->frame_size > 0 && s->buf_len[i] < s->frame_size) {
384
            av_log(ctx, AV_LOG_ERROR,
385
                   "buf_len[%d] = %d < expected frame size %d\n",
386
                   i, s->buf_len[i], s->frame_size);
387
            return AVERROR(ENOMEM);
388
        }
389
        s->buf_start[i] = v4l2_mmap(NULL, buf.length,
390
                               PROT_READ | PROT_WRITE, MAP_SHARED,
391
                               s->fd, buf.m.offset);
392
393
        if (s->buf_start[i] == MAP_FAILED) {
394
            res = AVERROR(errno);
395
            av_log(ctx, AV_LOG_ERROR, "mmap: %s\n", av_err2str(res));
396
            return res;
397
        }
398
    }
399
400
    return 0;
401
}
402
403
static int enqueue_buffer(struct video_data *s, struct v4l2_buffer *buf)
404
{
405
    int res = 0;
406
407
    if (v4l2_ioctl(s->fd, VIDIOC_QBUF, buf) < 0) {
408
        res = AVERROR(errno);
409
        av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", av_err2str(res));
410
    } else {
411
        atomic_fetch_add(&s->buffers_queued, 1);
412
    }
413
414
    return res;
415
}
416
417
static void mmap_release_buffer(void *opaque, uint8_t *data)
418
{
419
    struct v4l2_buffer buf = { 0 };
420
    struct buff_data *buf_descriptor = opaque;
421
    struct video_data *s = buf_descriptor->s;
422
423
    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
424
    buf.memory = V4L2_MEMORY_MMAP;
425
    buf.index = buf_descriptor->index;
426
    av_free(buf_descriptor);
427
428
    enqueue_buffer(s, &buf);
429
}
430
431
#if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
432
static int64_t av_gettime_monotonic(void)
433
{
434
    return av_gettime_relative();
435
}
436
#endif
437
438
static int init_convert_timestamp(AVFormatContext *ctx, int64_t ts)
439
{
440
    struct video_data *s = ctx->priv_data;
441
    int64_t now;
442
443
    now = av_gettime();
444
    if (s->ts_mode == V4L_TS_ABS &&
445
        ts <= now + 1 * AV_TIME_BASE && ts >= now - 10 * AV_TIME_BASE) {
446
        av_log(ctx, AV_LOG_INFO, "Detected absolute timestamps\n");
447
        s->ts_mode = V4L_TS_CONVERT_READY;
448
        return 0;
449
    }
450
#if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
451
    if (ctx->streams[0]->avg_frame_rate.num) {
452
        now = av_gettime_monotonic();
453
        if (s->ts_mode == V4L_TS_MONO2ABS ||
454
            (ts <= now + 1 * AV_TIME_BASE && ts >= now - 10 * AV_TIME_BASE)) {
455
            AVRational tb = {AV_TIME_BASE, 1};
456
            int64_t period = av_rescale_q(1, tb, ctx->streams[0]->avg_frame_rate);
457
            av_log(ctx, AV_LOG_INFO, "Detected monotonic timestamps, converting\n");
458
            /* microseconds instead of seconds, MHz instead of Hz */
459
            s->timefilter = ff_timefilter_new(1, period, 1.0E-6);
460
            if (!s->timefilter)
461
                return AVERROR(ENOMEM);
462
            s->ts_mode = V4L_TS_CONVERT_READY;
463
            return 0;
464
        }
465
    }
466
#endif
467
    av_log(ctx, AV_LOG_ERROR, "Unknown timestamps\n");
468
    return AVERROR(EIO);
469
}
470
471
static int convert_timestamp(AVFormatContext *ctx, int64_t *ts)
472
{
473
    struct video_data *s = ctx->priv_data;
474
475
    if (s->ts_mode) {
476
        int r = init_convert_timestamp(ctx, *ts);
477
        if (r < 0)
478
            return r;
479
    }
480
#if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
481
    if (s->timefilter) {
482
        int64_t nowa = av_gettime();
483
        int64_t nowm = av_gettime_monotonic();
484
        ff_timefilter_update(s->timefilter, nowa, nowm - s->last_time_m);
485
        s->last_time_m = nowm;
486
        *ts = ff_timefilter_eval(s->timefilter, *ts - nowm);
487
    }
488
#endif
489
    return 0;
490
}
491
492
static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
493
{
494
    struct video_data *s = ctx->priv_data;
495
    struct v4l2_buffer buf = {
496
        .type   = V4L2_BUF_TYPE_VIDEO_CAPTURE,
497
        .memory = V4L2_MEMORY_MMAP
498
    };
499
    struct timeval buf_ts;
500
    int res;
501
502
    pkt->size = 0;
503
504
    /* FIXME: Some special treatment might be needed in case of loss of signal... */
505
    while ((res = v4l2_ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 && (errno == EINTR));
506
    if (res < 0) {
507
        if (errno == EAGAIN)
508
            return AVERROR(EAGAIN);
509
510
        res = AVERROR(errno);
511
        av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n",
512
               av_err2str(res));
513
        return res;
514
    }
515
516
    buf_ts = buf.timestamp;
517
518
    if (buf.index >= s->buffers) {
519
        av_log(ctx, AV_LOG_ERROR, "Invalid buffer index received.\n");
520
        return AVERROR(EINVAL);
521
    }
522
    atomic_fetch_add(&s->buffers_queued, -1);
523
    // always keep at least one buffer queued
524
    av_assert0(atomic_load(&s->buffers_queued) >= 1);
525
526
#ifdef V4L2_BUF_FLAG_ERROR
527
    if (buf.flags & V4L2_BUF_FLAG_ERROR) {
528
        av_log(ctx, AV_LOG_WARNING,
529
               "Dequeued v4l2 buffer contains corrupted data (%d bytes).\n",
530
               buf.bytesused);
531
        buf.bytesused = 0;
532
    } else
533
#endif
534
    {
535
        /* CPIA is a compressed format and we don't know the exact number of bytes
536
         * used by a frame, so set it here as the driver announces it. */
537
        if (ctx->video_codec_id == AV_CODEC_ID_CPIA)
538
            s->frame_size = buf.bytesused;
539
540
        if (s->frame_size > 0 && buf.bytesused != s->frame_size) {
541
            av_log(ctx, AV_LOG_WARNING,
542
                   "Dequeued v4l2 buffer contains %d bytes, but %d were expected. Flags: 0x%08X.\n",
543
                   buf.bytesused, s->frame_size, buf.flags);
544
            buf.bytesused = 0;
545
        }
546
    }
547
548
    /* Image is at s->buff_start[buf.index] */
549
    if (atomic_load(&s->buffers_queued) == FFMAX(s->buffers / 8, 1)) {
550
        /* when we start getting low on queued buffers, fall back on copying data */
551
        res = av_new_packet(pkt, buf.bytesused);
552
        if (res < 0) {
553
            av_log(ctx, AV_LOG_ERROR, "Error allocating a packet.\n");
554
            enqueue_buffer(s, &buf);
555
            return res;
556
        }
557
        memcpy(pkt->data, s->buf_start[buf.index], buf.bytesused);
558
559
        res = enqueue_buffer(s, &buf);
560
        if (res) {
561
            av_packet_unref(pkt);
562
            return res;
563
        }
564
    } else {
565
        struct buff_data *buf_descriptor;
566
567
        pkt->data     = s->buf_start[buf.index];
568
        pkt->size     = buf.bytesused;
569
570
        buf_descriptor = av_malloc(sizeof(struct buff_data));
571
        if (!buf_descriptor) {
572
            /* Something went wrong... Since av_malloc() failed, we cannot even
573
             * allocate a buffer for memcpying into it
574
             */
575
            av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
576
            enqueue_buffer(s, &buf);
577
578
            return AVERROR(ENOMEM);
579
        }
580
        buf_descriptor->index = buf.index;
581
        buf_descriptor->s     = s;
582
583
        pkt->buf = av_buffer_create(pkt->data, pkt->size, mmap_release_buffer,
584
                                    buf_descriptor, 0);
585
        if (!pkt->buf) {
586
            av_log(ctx, AV_LOG_ERROR, "Failed to create a buffer\n");
587
            enqueue_buffer(s, &buf);
588
            av_freep(&buf_descriptor);
589
            return AVERROR(ENOMEM);
590
        }
591
    }
592
    pkt->pts = buf_ts.tv_sec * INT64_C(1000000) + buf_ts.tv_usec;
593
    convert_timestamp(ctx, &pkt->pts);
594
595
    return pkt->size;
596
}
597
598
static int mmap_start(AVFormatContext *ctx)
599
{
600
    struct video_data *s = ctx->priv_data;
601
    enum v4l2_buf_type type;
602
    int i, res;
603
604
    for (i = 0; i < s->buffers; i++) {
605
        struct v4l2_buffer buf = {
606
            .type   = V4L2_BUF_TYPE_VIDEO_CAPTURE,
607
            .index  = i,
608
            .memory = V4L2_MEMORY_MMAP
609
        };
610
611
        if (v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf) < 0) {
612
            res = AVERROR(errno);
613
            av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n",
614
                   av_err2str(res));
615
            return res;
616
        }
617
    }
618
    atomic_store(&s->buffers_queued, s->buffers);
619
620
    type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
621
    if (v4l2_ioctl(s->fd, VIDIOC_STREAMON, &type) < 0) {
622
        res = AVERROR(errno);
623
        av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n",
624
               av_err2str(res));
625
        return res;
626
    }
627
628
    return 0;
629
}
630
631
static void mmap_close(struct video_data *s)
632
{
633
    enum v4l2_buf_type type;
634
    int i;
635
636
    type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
637
    /* We do not check for the result, because we could
638
     * not do anything about it anyway...
639
     */
640
    v4l2_ioctl(s->fd, VIDIOC_STREAMOFF, &type);
641
    for (i = 0; i < s->buffers; i++) {
642
        v4l2_munmap(s->buf_start[i], s->buf_len[i]);
643
    }
644
    av_freep(&s->buf_start);
645
    av_freep(&s->buf_len);
646
}
647
648
static int v4l2_set_parameters(AVFormatContext *ctx)
649
{
650
    struct video_data *s = ctx->priv_data;
651
    struct v4l2_standard standard = { 0 };
652
    struct v4l2_streamparm streamparm = { 0 };
653
    struct v4l2_fract *tpf;
654
    AVRational framerate_q = { 0 };
655
    int i, ret;
656
657
    if (s->framerate &&
658
        (ret = av_parse_video_rate(&framerate_q, s->framerate)) < 0) {
659
        av_log(ctx, AV_LOG_ERROR, "Could not parse framerate '%s'.\n",
660
               s->framerate);
661
        return ret;
662
    }
663
664
    if (s->standard) {
665
        if (s->std_id) {
666
            ret = 0;
667
            av_log(ctx, AV_LOG_DEBUG, "Setting standard: %s\n", s->standard);
668
            /* set tv standard */
669
            for (i = 0; ; i++) {
670
                standard.index = i;
671
                if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
672
                    ret = AVERROR(errno);
673
                    break;
674
                }
675
                if (!av_strcasecmp(standard.name, s->standard))
676
                    break;
677
            }
678
            if (ret < 0) {
679
                av_log(ctx, AV_LOG_ERROR, "Unknown or unsupported standard '%s'\n", s->standard);
680
                return ret;
681
            }
682
683
            if (v4l2_ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
684
                ret = AVERROR(errno);
685
                av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_S_STD): %s\n", av_err2str(ret));
686
                return ret;
687
            }
688
        } else {
689
            av_log(ctx, AV_LOG_WARNING,
690
                   "This device does not support any standard\n");
691
        }
692
    }
693
694
    /* get standard */
695
    if (v4l2_ioctl(s->fd, VIDIOC_G_STD, &s->std_id) == 0) {
696
        tpf = &standard.frameperiod;
697
        for (i = 0; ; i++) {
698
            standard.index = i;
699
            if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
700
                ret = AVERROR(errno);
701
                if (ret == AVERROR(EINVAL)
702
#ifdef ENODATA
703
                    || ret == AVERROR(ENODATA)
704
#endif
705
                ) {
706
                    tpf = &streamparm.parm.capture.timeperframe;
707
                    break;
708
                }
709
                av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMSTD): %s\n", av_err2str(ret));
710
                return ret;
711
            }
712
            if (standard.id == s->std_id) {
713
                av_log(ctx, AV_LOG_DEBUG,
714
                       "Current standard: %s, id: %"PRIx64", frameperiod: %d/%d\n",
715
                       standard.name, (uint64_t)standard.id, tpf->numerator, tpf->denominator);
716
                break;
717
            }
718
        }
719
    } else {
720
        tpf = &streamparm.parm.capture.timeperframe;
721
    }
722
723
    streamparm.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
724
    if (v4l2_ioctl(s->fd, VIDIOC_G_PARM, &streamparm) < 0) {
725
        ret = AVERROR(errno);
726
        av_log(ctx, AV_LOG_WARNING, "ioctl(VIDIOC_G_PARM): %s\n", av_err2str(ret));
727
    } else if (framerate_q.num && framerate_q.den) {
728
        if (streamparm.parm.capture.capability & V4L2_CAP_TIMEPERFRAME) {
729
            tpf = &streamparm.parm.capture.timeperframe;
730
731
            av_log(ctx, AV_LOG_DEBUG, "Setting time per frame to %d/%d\n",
732
                   framerate_q.den, framerate_q.num);
733
            tpf->numerator   = framerate_q.den;
734
            tpf->denominator = framerate_q.num;
735
736
            if (v4l2_ioctl(s->fd, VIDIOC_S_PARM, &streamparm) < 0) {
737
                ret = AVERROR(errno);
738
                av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_S_PARM): %s\n",
739
                       av_err2str(ret));
740
                return ret;
741
            }
742
743
            if (framerate_q.num != tpf->denominator ||
744
                framerate_q.den != tpf->numerator) {
745
                av_log(ctx, AV_LOG_INFO,
746
                       "The driver changed the time per frame from "
747
                       "%d/%d to %d/%d\n",
748
                       framerate_q.den, framerate_q.num,
749
                       tpf->numerator, tpf->denominator);
750
            }
751
        } else {
752
            av_log(ctx, AV_LOG_WARNING,
753
                   "The driver does not permit changing the time per frame\n");
754
        }
755
    }
756
    if (tpf->denominator > 0 && tpf->numerator > 0) {
757
        ctx->streams[0]->avg_frame_rate.num = tpf->denominator;
758
        ctx->streams[0]->avg_frame_rate.den = tpf->numerator;
759
        ctx->streams[0]->r_frame_rate = ctx->streams[0]->avg_frame_rate;
760
    } else
761
        av_log(ctx, AV_LOG_WARNING, "Time per frame unknown\n");
762
763
    return 0;
764
}
765
766
static int device_try_init(AVFormatContext *ctx,
767
                           enum AVPixelFormat pix_fmt,
768
                           int *width,
769
                           int *height,
770
                           uint32_t *desired_format,
771
                           enum AVCodecID *codec_id)
772
{
773
    int ret, i;
774
775
    *desired_format = ff_fmt_ff2v4l(pix_fmt, ctx->video_codec_id);
776
777
    if (*desired_format) {
778
        ret = device_init(ctx, width, height, *desired_format);
779
        if (ret < 0) {
780
            *desired_format = 0;
781
            if (ret != AVERROR(EINVAL))
782
                return ret;
783
        }
784
    }
785
786
    if (!*desired_format) {
787
        for (i = 0; ff_fmt_conversion_table[i].codec_id != AV_CODEC_ID_NONE; i++) {
788
            if (ctx->video_codec_id == AV_CODEC_ID_NONE ||
789
                ff_fmt_conversion_table[i].codec_id == ctx->video_codec_id) {
790
                av_log(ctx, AV_LOG_DEBUG, "Trying to set codec:%s pix_fmt:%s\n",
791
                       avcodec_get_name(ff_fmt_conversion_table[i].codec_id),
792
                       (char *)av_x_if_null(av_get_pix_fmt_name(ff_fmt_conversion_table[i].ff_fmt), "none"));
793
794
                *desired_format = ff_fmt_conversion_table[i].v4l2_fmt;
795
                ret = device_init(ctx, width, height, *desired_format);
796
                if (ret >= 0)
797
                    break;
798
                else if (ret != AVERROR(EINVAL))
799
                    return ret;
800
                *desired_format = 0;
801
            }
802
        }
803
804
        if (*desired_format == 0) {
805
            av_log(ctx, AV_LOG_ERROR, "Cannot find a proper format for "
806
                   "codec '%s' (id %d), pixel format '%s' (id %d)\n",
807
                   avcodec_get_name(ctx->video_codec_id), ctx->video_codec_id,
808
                   (char *)av_x_if_null(av_get_pix_fmt_name(pix_fmt), "none"), pix_fmt);
809
            ret = AVERROR(EINVAL);
810
        }
811
    }
812
813
    *codec_id = ff_fmt_v4l2codec(*desired_format);
814
    if (*codec_id == AV_CODEC_ID_NONE)
815
        av_assert0(ret == AVERROR(EINVAL));
816
    return ret;
817
}
818
819
3269
static int v4l2_read_probe(const AVProbeData *p)
820
{
821
3269
    if (av_strstart(p->filename, "/dev/video", NULL))
822
        return AVPROBE_SCORE_MAX - 1;
823
3269
    return 0;
824
}
825
826
static int v4l2_read_header(AVFormatContext *ctx)
827
{
828
    struct video_data *s = ctx->priv_data;
829
    AVStream *st;
830
    int res = 0;
831
    uint32_t desired_format;
832
    enum AVCodecID codec_id = AV_CODEC_ID_NONE;
833
    enum AVPixelFormat pix_fmt = AV_PIX_FMT_NONE;
834
    struct v4l2_input input = { 0 };
835
836
    st = avformat_new_stream(ctx, NULL);
837
    if (!st)
838
        return AVERROR(ENOMEM);
839
840
#if CONFIG_LIBV4L2
841
    /* silence libv4l2 logging. if fopen() fails v4l2_log_file will be NULL
842
       and errors will get sent to stderr */
843
    if (s->use_libv4l2)
844
        v4l2_log_file = fopen("/dev/null", "w");
845
#endif
846
847
    s->fd = device_open(ctx, ctx->url);
848
    if (s->fd < 0)
849
        return s->fd;
850
851
    if (s->channel != -1) {
852
        /* set video input */
853
        av_log(ctx, AV_LOG_DEBUG, "Selecting input_channel: %d\n", s->channel);
854
        if (v4l2_ioctl(s->fd, VIDIOC_S_INPUT, &s->channel) < 0) {
855
            res = AVERROR(errno);
856
            av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_S_INPUT): %s\n", av_err2str(res));
857
            goto fail;
858
        }
859
    } else {
860
        /* get current video input */
861
        if (v4l2_ioctl(s->fd, VIDIOC_G_INPUT, &s->channel) < 0) {
862
            res = AVERROR(errno);
863
            av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_G_INPUT): %s\n", av_err2str(res));
864
            goto fail;
865
        }
866
    }
867
868
    /* enum input */
869
    input.index = s->channel;
870
    if (v4l2_ioctl(s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
871
        res = AVERROR(errno);
872
        av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMINPUT): %s\n", av_err2str(res));
873
        goto fail;
874
    }
875
    s->std_id = input.std;
876
    av_log(ctx, AV_LOG_DEBUG, "Current input_channel: %d, input_name: %s, input_std: %"PRIx64"\n",
877
           s->channel, input.name, (uint64_t)input.std);
878
879
    if (s->list_format) {
880
        list_formats(ctx, s->list_format);
881
        res = AVERROR_EXIT;
882
        goto fail;
883
    }
884
885
    if (s->list_standard) {
886
        list_standards(ctx);
887
        res = AVERROR_EXIT;
888
        goto fail;
889
    }
890
891
    avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
892
893
    if (s->pixel_format) {
894
        const AVCodecDescriptor *desc = avcodec_descriptor_get_by_name(s->pixel_format);
895
896
        if (desc)
897
            ctx->video_codec_id = desc->id;
898
899
        pix_fmt = av_get_pix_fmt(s->pixel_format);
900
901
        if (pix_fmt == AV_PIX_FMT_NONE && !desc) {
902
            av_log(ctx, AV_LOG_ERROR, "No such input format: %s.\n",
903
                   s->pixel_format);
904
905
            res = AVERROR(EINVAL);
906
            goto fail;
907
        }
908
    }
909
910
    if (!s->width && !s->height) {
911
        struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
912
913
        av_log(ctx, AV_LOG_VERBOSE,
914
               "Querying the device for the current frame size\n");
915
        if (v4l2_ioctl(s->fd, VIDIOC_G_FMT, &fmt) < 0) {
916
            res = AVERROR(errno);
917
            av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n",
918
                   av_err2str(res));
919
            goto fail;
920
        }
921
922
        s->width  = fmt.fmt.pix.width;
923
        s->height = fmt.fmt.pix.height;
924
        av_log(ctx, AV_LOG_VERBOSE,
925
               "Setting frame size to %dx%d\n", s->width, s->height);
926
    }
927
928
    res = device_try_init(ctx, pix_fmt, &s->width, &s->height, &desired_format, &codec_id);
929
    if (res < 0)
930
        goto fail;
931
932
    /* If no pixel_format was specified, the codec_id was not known up
933
     * until now. Set video_codec_id in the context, as codec_id will
934
     * not be available outside this function
935
     */
936
    if (codec_id != AV_CODEC_ID_NONE && ctx->video_codec_id == AV_CODEC_ID_NONE)
937
        ctx->video_codec_id = codec_id;
938
939
    if ((res = av_image_check_size(s->width, s->height, 0, ctx)) < 0)
940
        goto fail;
941
942
    s->pixelformat = desired_format;
943
944
    if ((res = v4l2_set_parameters(ctx)) < 0)
945
        goto fail;
946
947
    st->codecpar->format = ff_fmt_v4l2ff(desired_format, codec_id);
948
    if (st->codecpar->format != AV_PIX_FMT_NONE)
949
        s->frame_size = av_image_get_buffer_size(st->codecpar->format,
950
                                                 s->width, s->height, 1);
951
952
    if ((res = mmap_init(ctx)) ||
953
        (res = mmap_start(ctx)) < 0)
954
            goto fail;
955
956
    s->top_field_first = first_field(s);
957
958
    st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
959
    st->codecpar->codec_id = codec_id;
960
    if (codec_id == AV_CODEC_ID_RAWVIDEO)
961
        st->codecpar->codec_tag =
962
            avcodec_pix_fmt_to_codec_tag(st->codecpar->format);
963
    else if (codec_id == AV_CODEC_ID_H264) {
964
        st->need_parsing = AVSTREAM_PARSE_FULL_ONCE;
965
    }
966
    if (desired_format == V4L2_PIX_FMT_YVU420)
967
        st->codecpar->codec_tag = MKTAG('Y', 'V', '1', '2');
968
    else if (desired_format == V4L2_PIX_FMT_YVU410)
969
        st->codecpar->codec_tag = MKTAG('Y', 'V', 'U', '9');
970
    st->codecpar->width = s->width;
971
    st->codecpar->height = s->height;
972
    if (st->avg_frame_rate.den)
973
        st->codecpar->bit_rate = s->frame_size * av_q2d(st->avg_frame_rate) * 8;
974
975
    return 0;
976
977
fail:
978
    v4l2_close(s->fd);
979
    return res;
980
}
981
982
static int v4l2_read_packet(AVFormatContext *ctx, AVPacket *pkt)
983
{
984
#if FF_API_CODED_FRAME && FF_API_LAVF_AVCTX
985
FF_DISABLE_DEPRECATION_WARNINGS
986
    struct video_data *s = ctx->priv_data;
987
    AVFrame *frame = ctx->streams[0]->codec->coded_frame;
988
FF_ENABLE_DEPRECATION_WARNINGS
989
#endif
990
    int res;
991
992
    if ((res = mmap_read_frame(ctx, pkt)) < 0) {
993
        return res;
994
    }
995
996
#if FF_API_CODED_FRAME && FF_API_LAVF_AVCTX
997
FF_DISABLE_DEPRECATION_WARNINGS
998
    if (frame && s->interlaced) {
999
        frame->interlaced_frame = 1;
1000
        frame->top_field_first = s->top_field_first;
1001
    }
1002
FF_ENABLE_DEPRECATION_WARNINGS
1003
#endif
1004
1005
    return pkt->size;
1006
}
1007
1008
static int v4l2_read_close(AVFormatContext *ctx)
1009
{
1010
    struct video_data *s = ctx->priv_data;
1011
1012
    if (atomic_load(&s->buffers_queued) != s->buffers)
1013
        av_log(ctx, AV_LOG_WARNING, "Some buffers are still owned by the caller on "
1014
               "close.\n");
1015
1016
    mmap_close(s);
1017
1018
    v4l2_close(s->fd);
1019
    return 0;
1020
}
1021
1022
static int v4l2_is_v4l_dev(const char *name)
1023
{
1024
    return !strncmp(name, "video", 5) ||
1025
           !strncmp(name, "radio", 5) ||
1026
           !strncmp(name, "vbi", 3) ||
1027
           !strncmp(name, "v4l-subdev", 10);
1028
}
1029
1030
static int v4l2_get_device_list(AVFormatContext *ctx, AVDeviceInfoList *device_list)
1031
{
1032
    struct video_data *s = ctx->priv_data;
1033
    DIR *dir;
1034
    struct dirent *entry;
1035
    AVDeviceInfo *device = NULL;
1036
    struct v4l2_capability cap;
1037
    int ret = 0;
1038
1039
    if (!device_list)
1040
        return AVERROR(EINVAL);
1041
1042
    dir = opendir("/dev");
1043
    if (!dir) {
1044
        ret = AVERROR(errno);
1045
        av_log(ctx, AV_LOG_ERROR, "Couldn't open the directory: %s\n", av_err2str(ret));
1046
        return ret;
1047
    }
1048
    while ((entry = readdir(dir))) {
1049
        char device_name[256];
1050
1051
        if (!v4l2_is_v4l_dev(entry->d_name))
1052
            continue;
1053
1054
        snprintf(device_name, sizeof(device_name), "/dev/%s", entry->d_name);
1055
        if ((s->fd = device_open(ctx, device_name)) < 0)
1056
            continue;
1057
1058
        if (v4l2_ioctl(s->fd, VIDIOC_QUERYCAP, &cap) < 0) {
1059
            ret = AVERROR(errno);
1060
            av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n", av_err2str(ret));
1061
            goto fail;
1062
        }
1063
1064
        device = av_mallocz(sizeof(AVDeviceInfo));
1065
        if (!device) {
1066
            ret = AVERROR(ENOMEM);
1067
            goto fail;
1068
        }
1069
        device->device_name = av_strdup(device_name);
1070
        device->device_description = av_strdup(cap.card);
1071
        if (!device->device_name || !device->device_description) {
1072
            ret = AVERROR(ENOMEM);
1073
            goto fail;
1074
        }
1075
1076
        if ((ret = av_dynarray_add_nofree(&device_list->devices,
1077
                                          &device_list->nb_devices, device)) < 0)
1078
            goto fail;
1079
1080
        v4l2_close(s->fd);
1081
        s->fd = -1;
1082
        continue;
1083
1084
      fail:
1085
        if (device) {
1086
            av_freep(&device->device_name);
1087
            av_freep(&device->device_description);
1088
            av_freep(&device);
1089
        }
1090
        if (s->fd >= 0)
1091
            v4l2_close(s->fd);
1092
        s->fd = -1;
1093
        break;
1094
    }
1095
    closedir(dir);
1096
    return ret;
1097
}
1098
1099
#define OFFSET(x) offsetof(struct video_data, x)
1100
#define DEC AV_OPT_FLAG_DECODING_PARAM
1101
1102
static const AVOption options[] = {
1103
    { "standard",     "set TV standard, used only by analog frame grabber",       OFFSET(standard),     AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0,       DEC },
1104
    { "channel",      "set TV channel, used only by frame grabber",               OFFSET(channel),      AV_OPT_TYPE_INT,    {.i64 = -1 },  -1, INT_MAX, DEC },
1105
    { "video_size",   "set frame size",                                           OFFSET(width),        AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL},  0, 0,   DEC },
1106
    { "pixel_format", "set preferred pixel format",                               OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       DEC },
1107
    { "input_format", "set preferred pixel format (for raw video) or codec name", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       DEC },
1108
    { "framerate",    "set frame rate",                                           OFFSET(framerate),    AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       DEC },
1109
1110
    { "list_formats", "list available formats and exit",                          OFFSET(list_format),  AV_OPT_TYPE_INT,    {.i64 = 0 },  0, INT_MAX, DEC, "list_formats" },
1111
    { "all",          "show all available formats",                               OFFSET(list_format),  AV_OPT_TYPE_CONST,  {.i64 = V4L_ALLFORMATS  },    0, INT_MAX, DEC, "list_formats" },
1112
    { "raw",          "show only non-compressed formats",                         OFFSET(list_format),  AV_OPT_TYPE_CONST,  {.i64 = V4L_RAWFORMATS  },    0, INT_MAX, DEC, "list_formats" },
1113
    { "compressed",   "show only compressed formats",                             OFFSET(list_format),  AV_OPT_TYPE_CONST,  {.i64 = V4L_COMPFORMATS },    0, INT_MAX, DEC, "list_formats" },
1114
1115
    { "list_standards", "list supported standards and exit",                      OFFSET(list_standard), AV_OPT_TYPE_INT,   {.i64 = 0 },  0, 1, DEC, "list_standards" },
1116
    { "all",            "show all supported standards",                           OFFSET(list_standard), AV_OPT_TYPE_CONST, {.i64 = 1 },  0, 0, DEC, "list_standards" },
1117
1118
    { "timestamps",   "set type of timestamps for grabbed frames",                OFFSET(ts_mode),      AV_OPT_TYPE_INT,    {.i64 = 0 }, 0, 2, DEC, "timestamps" },
1119
    { "ts",           "set type of timestamps for grabbed frames",                OFFSET(ts_mode),      AV_OPT_TYPE_INT,    {.i64 = 0 }, 0, 2, DEC, "timestamps" },
1120
    { "default",      "use timestamps from the kernel",                           OFFSET(ts_mode),      AV_OPT_TYPE_CONST,  {.i64 = V4L_TS_DEFAULT  }, 0, 2, DEC, "timestamps" },
1121
    { "abs",          "use absolute timestamps (wall clock)",                     OFFSET(ts_mode),      AV_OPT_TYPE_CONST,  {.i64 = V4L_TS_ABS      }, 0, 2, DEC, "timestamps" },
1122
    { "mono2abs",     "force conversion from monotonic to absolute timestamps",   OFFSET(ts_mode),      AV_OPT_TYPE_CONST,  {.i64 = V4L_TS_MONO2ABS }, 0, 2, DEC, "timestamps" },
1123
    { "use_libv4l2",  "use libv4l2 (v4l-utils) conversion functions",             OFFSET(use_libv4l2),  AV_OPT_TYPE_BOOL,   {.i64 = 0}, 0, 1, DEC },
1124
    { NULL },
1125
};
1126
1127
static const AVClass v4l2_class = {
1128
    .class_name = "V4L2 indev",
1129
    .item_name  = av_default_item_name,
1130
    .option     = options,
1131
    .version    = LIBAVUTIL_VERSION_INT,
1132
    .category   = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
1133
};
1134
1135
AVInputFormat ff_v4l2_demuxer = {
1136
    .name           = "video4linux2,v4l2",
1137
    .long_name      = NULL_IF_CONFIG_SMALL("Video4Linux2 device grab"),
1138
    .priv_data_size = sizeof(struct video_data),
1139
    .read_probe     = v4l2_read_probe,
1140
    .read_header    = v4l2_read_header,
1141
    .read_packet    = v4l2_read_packet,
1142
    .read_close     = v4l2_read_close,
1143
    .get_device_list = v4l2_get_device_list,
1144
    .flags          = AVFMT_NOFILE,
1145
    .priv_class     = &v4l2_class,
1146
};