FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavdevice/v4l2.c
Date: 2024-07-14 13:34:57
Exec Total Coverage
Lines: 3 569 0.5%
Functions: 1 23 4.3%
Branches: 1 321 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 "libavutil/avassert.h"
36 #include "libavutil/avstring.h"
37 #include "libavutil/imgutils.h"
38 #include "libavutil/mem.h"
39 #include "libavutil/parseutils.h"
40 #include "libavutil/pixdesc.h"
41 #include "libavutil/time.h"
42 #include "libavcodec/avcodec.h"
43 #include "libavcodec/codec_desc.h"
44 #include "libavformat/demux.h"
45 #include "libavformat/internal.h"
46 #include "avdevice.h"
47 #include "timefilter.h"
48 #include "v4l2-common.h"
49 #include <dirent.h>
50
51 #if CONFIG_LIBV4L2
52 #include <libv4l2.h>
53 #endif
54
55 static const int desired_video_buffers = 256;
56
57 #define V4L_ALLFORMATS 3
58 #define V4L_RAWFORMATS 1
59 #define V4L_COMPFORMATS 2
60
61 /**
62 * Return timestamps to the user exactly as returned by the kernel
63 */
64 #define V4L_TS_DEFAULT 0
65 /**
66 * Autodetect the kind of timestamps returned by the kernel and convert to
67 * absolute (wall clock) timestamps.
68 */
69 #define V4L_TS_ABS 1
70 /**
71 * Assume kernel timestamps are from the monotonic clock and convert to
72 * absolute timestamps.
73 */
74 #define V4L_TS_MONO2ABS 2
75
76 /**
77 * Once the kind of timestamps returned by the kernel have been detected,
78 * the value of the timefilter (NULL or not) determines whether a conversion
79 * takes place.
80 */
81 #define V4L_TS_CONVERT_READY V4L_TS_DEFAULT
82
83 struct video_data {
84 AVClass *class;
85 int fd;
86 int pixelformat; /* V4L2_PIX_FMT_* */
87 int width, height;
88 int frame_size;
89 int interlaced;
90 int top_field_first;
91 int ts_mode;
92 TimeFilter *timefilter;
93 int64_t last_time_m;
94
95 int multiplanar;
96 enum v4l2_buf_type buf_type;
97
98 int buffers;
99 atomic_int buffers_queued;
100 void **buf_start;
101 unsigned int *buf_len;
102 char *standard;
103 v4l2_std_id std_id;
104 int channel;
105 char *pixel_format; /**< Set by a private option. */
106 int list_format; /**< Set by a private option. */
107 int list_standard; /**< Set by a private option. */
108 char *framerate; /**< Set by a private option. */
109
110 int use_libv4l2;
111 int (*open_f)(const char *file, int oflag, ...);
112 int (*close_f)(int fd);
113 int (*dup_f)(int fd);
114 #if defined(__sun) || defined(__BIONIC__) || defined(__musl__) /* POSIX-like */
115 int (*ioctl_f)(int fd, int request, ...);
116 #else
117 int (*ioctl_f)(int fd, unsigned long int request, ...);
118 #endif
119 ssize_t (*read_f)(int fd, void *buffer, size_t n);
120 void *(*mmap_f)(void *start, size_t length, int prot, int flags, int fd, int64_t offset);
121 int (*munmap_f)(void *_start, size_t length);
122 };
123
124 struct buff_data {
125 struct video_data *s;
126 int index;
127 };
128
129 static int device_open(AVFormatContext *ctx, const char* device_path)
130 {
131 struct video_data *s = ctx->priv_data;
132 struct v4l2_capability cap;
133 int fd;
134 int err;
135 int flags = O_RDWR;
136
137 #define SET_WRAPPERS(prefix) do { \
138 s->open_f = prefix ## open; \
139 s->close_f = prefix ## close; \
140 s->dup_f = prefix ## dup; \
141 s->ioctl_f = prefix ## ioctl; \
142 s->read_f = prefix ## read; \
143 s->mmap_f = prefix ## mmap; \
144 s->munmap_f = prefix ## munmap; \
145 } while (0)
146
147 if (s->use_libv4l2) {
148 #if CONFIG_LIBV4L2
149 SET_WRAPPERS(v4l2_);
150 #else
151 av_log(ctx, AV_LOG_ERROR, "libavdevice is not built with libv4l2 support.\n");
152 return AVERROR(EINVAL);
153 #endif
154 } else {
155 SET_WRAPPERS();
156 }
157
158 #define v4l2_open s->open_f
159 #define v4l2_close s->close_f
160 #define v4l2_dup s->dup_f
161 #define v4l2_ioctl s->ioctl_f
162 #define v4l2_read s->read_f
163 #define v4l2_mmap s->mmap_f
164 #define v4l2_munmap s->munmap_f
165
166 if (ctx->flags & AVFMT_FLAG_NONBLOCK) {
167 flags |= O_NONBLOCK;
168 }
169
170 fd = v4l2_open(device_path, flags, 0);
171 if (fd < 0) {
172 err = AVERROR(errno);
173 av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s: %s\n",
174 device_path, av_err2str(err));
175 return err;
176 }
177
178 if (v4l2_ioctl(fd, VIDIOC_QUERYCAP, &cap) < 0) {
179 err = AVERROR(errno);
180 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
181 av_err2str(err));
182 goto fail;
183 }
184
185 av_log(ctx, AV_LOG_VERBOSE, "fd:%d capabilities:%x\n",
186 fd, cap.capabilities);
187
188 if (cap.capabilities & V4L2_CAP_VIDEO_CAPTURE) {
189 s->multiplanar = 0;
190 s->buf_type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
191 } else if (cap.capabilities & V4L2_CAP_VIDEO_CAPTURE_MPLANE) {
192 s->multiplanar = 1;
193 s->buf_type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
194 } else {
195 av_log(ctx, AV_LOG_ERROR, "Not a video capture device.\n");
196 err = AVERROR(ENODEV);
197 goto fail;
198 }
199
200 if (!(cap.capabilities & V4L2_CAP_STREAMING)) {
201 av_log(ctx, AV_LOG_ERROR,
202 "The device does not support the streaming I/O method.\n");
203 err = AVERROR(ENOSYS);
204 goto fail;
205 }
206
207 return fd;
208
209 fail:
210 v4l2_close(fd);
211 return err;
212 }
213
214 static int device_init(AVFormatContext *ctx, int *width, int *height,
215 uint32_t pixelformat)
216 {
217 struct video_data *s = ctx->priv_data;
218 struct v4l2_format fmt = { .type = s->buf_type };
219 int res = 0;
220
221 fmt.fmt.pix.width = *width;
222 fmt.fmt.pix.height = *height;
223 fmt.fmt.pix.pixelformat = pixelformat;
224 fmt.fmt.pix.field = V4L2_FIELD_ANY;
225
226 /* Some drivers will fail and return EINVAL when the pixelformat
227 is not supported (even if type field is valid and supported) */
228 if (v4l2_ioctl(s->fd, VIDIOC_S_FMT, &fmt) < 0)
229 res = AVERROR(errno);
230
231 if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {
232 av_log(ctx, AV_LOG_INFO,
233 "The V4L2 driver changed the video from %dx%d to %dx%d\n",
234 *width, *height, fmt.fmt.pix.width, fmt.fmt.pix.height);
235 *width = fmt.fmt.pix.width;
236 *height = fmt.fmt.pix.height;
237 }
238
239 if (pixelformat != fmt.fmt.pix.pixelformat) {
240 av_log(ctx, AV_LOG_DEBUG,
241 "The V4L2 driver changed the pixel format "
242 "from 0x%08X to 0x%08X\n",
243 pixelformat, fmt.fmt.pix.pixelformat);
244 res = AVERROR(EINVAL);
245 }
246
247 if (fmt.fmt.pix.field == V4L2_FIELD_INTERLACED) {
248 av_log(ctx, AV_LOG_DEBUG,
249 "The V4L2 driver is using the interlaced mode\n");
250 s->interlaced = 1;
251 }
252
253 return res;
254 }
255
256 static int first_field(const struct video_data *s)
257 {
258 int res;
259 v4l2_std_id std;
260
261 res = v4l2_ioctl(s->fd, VIDIOC_G_STD, &std);
262 if (res < 0)
263 return 0;
264 if (std & V4L2_STD_NTSC)
265 return 0;
266
267 return 1;
268 }
269
270 #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
271 static void list_framesizes(AVFormatContext *ctx, uint32_t pixelformat)
272 {
273 const struct video_data *s = ctx->priv_data;
274 struct v4l2_frmsizeenum vfse = { .pixel_format = pixelformat };
275
276 while(!v4l2_ioctl(s->fd, VIDIOC_ENUM_FRAMESIZES, &vfse)) {
277 switch (vfse.type) {
278 case V4L2_FRMSIZE_TYPE_DISCRETE:
279 av_log(ctx, AV_LOG_INFO, " %ux%u",
280 vfse.discrete.width, vfse.discrete.height);
281 break;
282 case V4L2_FRMSIZE_TYPE_CONTINUOUS:
283 case V4L2_FRMSIZE_TYPE_STEPWISE:
284 av_log(ctx, AV_LOG_INFO, " {%u-%u, %u}x{%u-%u, %u}",
285 vfse.stepwise.min_width,
286 vfse.stepwise.max_width,
287 vfse.stepwise.step_width,
288 vfse.stepwise.min_height,
289 vfse.stepwise.max_height,
290 vfse.stepwise.step_height);
291 }
292 vfse.index++;
293 }
294 }
295 #endif
296
297 static void list_formats(AVFormatContext *ctx, int type)
298 {
299 const struct video_data *s = ctx->priv_data;
300 struct v4l2_fmtdesc vfd = { .type = s->buf_type };
301
302 while(!v4l2_ioctl(s->fd, VIDIOC_ENUM_FMT, &vfd)) {
303 enum AVCodecID codec_id = ff_fmt_v4l2codec(vfd.pixelformat);
304 enum AVPixelFormat pix_fmt = ff_fmt_v4l2ff(vfd.pixelformat, codec_id);
305
306 vfd.index++;
307
308 if (!(vfd.flags & V4L2_FMT_FLAG_COMPRESSED) &&
309 type & V4L_RAWFORMATS) {
310 const char *fmt_name = av_get_pix_fmt_name(pix_fmt);
311 av_log(ctx, AV_LOG_INFO, "Raw : %11s : %20s :",
312 fmt_name ? fmt_name : "Unsupported",
313 vfd.description);
314 } else if (vfd.flags & V4L2_FMT_FLAG_COMPRESSED &&
315 type & V4L_COMPFORMATS) {
316 const AVCodecDescriptor *desc = avcodec_descriptor_get(codec_id);
317 av_log(ctx, AV_LOG_INFO, "Compressed: %11s : %20s :",
318 desc ? desc->name : "Unsupported",
319 vfd.description);
320 } else {
321 continue;
322 }
323
324 #ifdef V4L2_FMT_FLAG_EMULATED
325 if (vfd.flags & V4L2_FMT_FLAG_EMULATED)
326 av_log(ctx, AV_LOG_INFO, " Emulated :");
327 #endif
328 #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
329 list_framesizes(ctx, vfd.pixelformat);
330 #endif
331 av_log(ctx, AV_LOG_INFO, "\n");
332 }
333 }
334
335 static void list_standards(AVFormatContext *ctx)
336 {
337 int ret;
338 struct video_data *s = ctx->priv_data;
339 struct v4l2_standard standard;
340
341 if (s->std_id == 0)
342 return;
343
344 for (standard.index = 0; ; standard.index++) {
345 if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
346 ret = AVERROR(errno);
347 if (ret == AVERROR(EINVAL)) {
348 break;
349 } else {
350 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMSTD): %s\n", av_err2str(ret));
351 return;
352 }
353 }
354 av_log(ctx, AV_LOG_INFO, "%2d, %16"PRIx64", %s\n",
355 standard.index, (uint64_t)standard.id, standard.name);
356 }
357 }
358
359 static int mmap_init(AVFormatContext *ctx)
360 {
361 int i, res;
362 struct video_data *s = ctx->priv_data;
363 struct v4l2_requestbuffers req = {
364 .type = s->buf_type,
365 .count = desired_video_buffers,
366 .memory = V4L2_MEMORY_MMAP
367 };
368
369 if (v4l2_ioctl(s->fd, VIDIOC_REQBUFS, &req) < 0) {
370 res = AVERROR(errno);
371 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS): %s\n", av_err2str(res));
372 return res;
373 }
374
375 if (req.count < 2) {
376 av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");
377 return AVERROR(ENOMEM);
378 }
379 s->buffers = req.count;
380 s->buf_start = av_malloc_array(s->buffers, sizeof(void *));
381 if (!s->buf_start) {
382 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
383 return AVERROR(ENOMEM);
384 }
385 s->buf_len = av_malloc_array(s->buffers, sizeof(unsigned int));
386 if (!s->buf_len) {
387 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
388 av_freep(&s->buf_start);
389 return AVERROR(ENOMEM);
390 }
391
392 for (i = 0; i < req.count; i++) {
393 unsigned int buf_length, buf_offset;
394 struct v4l2_plane planes[VIDEO_MAX_PLANES];
395 struct v4l2_buffer buf = {
396 .type = s->buf_type,
397 .index = i,
398 .memory = V4L2_MEMORY_MMAP,
399 .m.planes = s->multiplanar ? planes : NULL,
400 .length = s->multiplanar ? VIDEO_MAX_PLANES : 0,
401 };
402 if (v4l2_ioctl(s->fd, VIDIOC_QUERYBUF, &buf) < 0) {
403 res = AVERROR(errno);
404 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF): %s\n", av_err2str(res));
405 return res;
406 }
407
408 if (s->multiplanar) {
409 if (buf.length != 1) {
410 av_log(ctx, AV_LOG_ERROR, "multiplanar only supported when buf.length == 1\n");
411 return AVERROR_PATCHWELCOME;
412 }
413 buf_length = buf.m.planes[0].length;
414 buf_offset = buf.m.planes[0].m.mem_offset;
415 } else {
416 buf_length = buf.length;
417 buf_offset = buf.m.offset;
418 }
419
420 s->buf_len[i] = buf_length;
421 if (s->frame_size > 0 && s->buf_len[i] < s->frame_size) {
422 av_log(ctx, AV_LOG_ERROR,
423 "buf_len[%d] = %d < expected frame size %d\n",
424 i, s->buf_len[i], s->frame_size);
425 return AVERROR(ENOMEM);
426 }
427 s->buf_start[i] = v4l2_mmap(NULL, buf_length,
428 PROT_READ | PROT_WRITE, MAP_SHARED,
429 s->fd, buf_offset);
430
431 if (s->buf_start[i] == MAP_FAILED) {
432 res = AVERROR(errno);
433 av_log(ctx, AV_LOG_ERROR, "mmap: %s\n", av_err2str(res));
434 return res;
435 }
436 }
437
438 return 0;
439 }
440
441 static int enqueue_buffer(struct video_data *s, struct v4l2_buffer *buf)
442 {
443 int res = 0;
444
445 if (v4l2_ioctl(s->fd, VIDIOC_QBUF, buf) < 0) {
446 res = AVERROR(errno);
447 av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", av_err2str(res));
448 } else {
449 atomic_fetch_add(&s->buffers_queued, 1);
450 }
451
452 return res;
453 }
454
455 static void mmap_release_buffer(void *opaque, uint8_t *data)
456 {
457 struct v4l2_plane planes[VIDEO_MAX_PLANES];
458 struct v4l2_buffer buf = { 0 };
459 struct buff_data *buf_descriptor = opaque;
460 struct video_data *s = buf_descriptor->s;
461
462 buf.type = s->buf_type;
463 buf.memory = V4L2_MEMORY_MMAP;
464 buf.index = buf_descriptor->index;
465 buf.m.planes = s->multiplanar ? planes : NULL;
466 buf.length = s->multiplanar ? VIDEO_MAX_PLANES : 0;
467 av_free(buf_descriptor);
468
469 enqueue_buffer(s, &buf);
470 }
471
472 #if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
473 static int64_t av_gettime_monotonic(void)
474 {
475 return av_gettime_relative();
476 }
477 #endif
478
479 static int init_convert_timestamp(AVFormatContext *ctx, int64_t ts)
480 {
481 struct video_data *s = ctx->priv_data;
482 int64_t now;
483
484 now = av_gettime();
485 if (s->ts_mode == V4L_TS_ABS &&
486 ts <= now + 1 * AV_TIME_BASE && ts >= now - 10 * AV_TIME_BASE) {
487 av_log(ctx, AV_LOG_INFO, "Detected absolute timestamps\n");
488 s->ts_mode = V4L_TS_CONVERT_READY;
489 return 0;
490 }
491 #if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
492 if (ctx->streams[0]->avg_frame_rate.num) {
493 now = av_gettime_monotonic();
494 if (s->ts_mode == V4L_TS_MONO2ABS ||
495 (ts <= now + 1 * AV_TIME_BASE && ts >= now - 10 * AV_TIME_BASE)) {
496 AVRational tb = {AV_TIME_BASE, 1};
497 int64_t period = av_rescale_q(1, tb, ctx->streams[0]->avg_frame_rate);
498 av_log(ctx, AV_LOG_INFO, "Detected monotonic timestamps, converting\n");
499 /* microseconds instead of seconds, MHz instead of Hz */
500 s->timefilter = ff_timefilter_new(1, period, 1.0E-6);
501 if (!s->timefilter)
502 return AVERROR(ENOMEM);
503 s->ts_mode = V4L_TS_CONVERT_READY;
504 return 0;
505 }
506 }
507 #endif
508 av_log(ctx, AV_LOG_ERROR, "Unknown timestamps\n");
509 return AVERROR(EIO);
510 }
511
512 static int convert_timestamp(AVFormatContext *ctx, int64_t *ts)
513 {
514 struct video_data *s = ctx->priv_data;
515
516 if (s->ts_mode) {
517 int r = init_convert_timestamp(ctx, *ts);
518 if (r < 0)
519 return r;
520 }
521 #if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
522 if (s->timefilter) {
523 int64_t nowa = av_gettime();
524 int64_t nowm = av_gettime_monotonic();
525 ff_timefilter_update(s->timefilter, nowa, nowm - s->last_time_m);
526 s->last_time_m = nowm;
527 *ts = ff_timefilter_eval(s->timefilter, *ts - nowm);
528 }
529 #endif
530 return 0;
531 }
532
533 static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
534 {
535 struct video_data *s = ctx->priv_data;
536 struct v4l2_plane planes[VIDEO_MAX_PLANES];
537 struct v4l2_buffer buf = {
538 .type = s->buf_type,
539 .memory = V4L2_MEMORY_MMAP,
540 .m.planes = s->multiplanar ? planes : NULL,
541 .length = s->multiplanar ? VIDEO_MAX_PLANES : 0,
542 };
543 struct timeval buf_ts;
544 unsigned int bytesused;
545 int res;
546
547 pkt->size = 0;
548
549 /* FIXME: Some special treatment might be needed in case of loss of signal... */
550 while ((res = v4l2_ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 && (errno == EINTR));
551 if (res < 0) {
552 if (errno == EAGAIN)
553 return AVERROR(EAGAIN);
554
555 res = AVERROR(errno);
556 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n",
557 av_err2str(res));
558 return res;
559 }
560
561 buf_ts = buf.timestamp;
562
563 if (buf.index >= s->buffers) {
564 av_log(ctx, AV_LOG_ERROR, "Invalid buffer index received.\n");
565 return AVERROR(EINVAL);
566 }
567 atomic_fetch_add(&s->buffers_queued, -1);
568 // always keep at least one buffer queued
569 av_assert0(atomic_load(&s->buffers_queued) >= 1);
570
571 bytesused = s->multiplanar ? buf.m.planes[0].bytesused : buf.bytesused;
572
573 #ifdef V4L2_BUF_FLAG_ERROR
574 if (buf.flags & V4L2_BUF_FLAG_ERROR) {
575 av_log(ctx, AV_LOG_WARNING,
576 "Dequeued v4l2 buffer contains corrupted data (%d bytes).\n",
577 bytesused);
578 bytesused = 0;
579 } else
580 #endif
581 {
582 /* CPIA is a compressed format and we don't know the exact number of bytes
583 * used by a frame, so set it here as the driver announces it. */
584 if (ctx->video_codec_id == AV_CODEC_ID_CPIA)
585 s->frame_size = bytesused;
586
587 if (s->frame_size > 0 && bytesused != s->frame_size) {
588 av_log(ctx, AV_LOG_WARNING,
589 "Dequeued v4l2 buffer contains %d bytes, but %d were expected. Flags: 0x%08X.\n",
590 bytesused, s->frame_size, buf.flags);
591 bytesused = 0;
592 }
593 }
594
595 /* Image is at s->buff_start[buf.index] */
596 if (atomic_load(&s->buffers_queued) == FFMAX(s->buffers / 8, 1)) {
597 /* when we start getting low on queued buffers, fall back on copying data */
598 res = av_new_packet(pkt, bytesused);
599 if (res < 0) {
600 av_log(ctx, AV_LOG_ERROR, "Error allocating a packet.\n");
601 enqueue_buffer(s, &buf);
602 return res;
603 }
604 memcpy(pkt->data, s->buf_start[buf.index], bytesused);
605
606 res = enqueue_buffer(s, &buf);
607 if (res) {
608 av_packet_unref(pkt);
609 return res;
610 }
611 } else {
612 struct buff_data *buf_descriptor;
613
614 pkt->data = s->buf_start[buf.index];
615 pkt->size = bytesused;
616
617 buf_descriptor = av_malloc(sizeof(struct buff_data));
618 if (!buf_descriptor) {
619 /* Something went wrong... Since av_malloc() failed, we cannot even
620 * allocate a buffer for memcpying into it
621 */
622 av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
623 enqueue_buffer(s, &buf);
624
625 return AVERROR(ENOMEM);
626 }
627 buf_descriptor->index = buf.index;
628 buf_descriptor->s = s;
629
630 pkt->buf = av_buffer_create(pkt->data, pkt->size, mmap_release_buffer,
631 buf_descriptor, 0);
632 if (!pkt->buf) {
633 av_log(ctx, AV_LOG_ERROR, "Failed to create a buffer\n");
634 enqueue_buffer(s, &buf);
635 av_freep(&buf_descriptor);
636 return AVERROR(ENOMEM);
637 }
638 }
639 pkt->pts = buf_ts.tv_sec * INT64_C(1000000) + buf_ts.tv_usec;
640 convert_timestamp(ctx, &pkt->pts);
641
642 return pkt->size;
643 }
644
645 static int mmap_start(AVFormatContext *ctx)
646 {
647 struct video_data *s = ctx->priv_data;
648 enum v4l2_buf_type type;
649 int i, res;
650
651 for (i = 0; i < s->buffers; i++) {
652 struct v4l2_plane planes[VIDEO_MAX_PLANES];
653 struct v4l2_buffer buf = {
654 .type = s->buf_type,
655 .index = i,
656 .memory = V4L2_MEMORY_MMAP,
657 .m.planes = s->multiplanar ? planes : NULL,
658 .length = s->multiplanar ? VIDEO_MAX_PLANES : 0,
659 };
660
661 if (v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf) < 0) {
662 res = AVERROR(errno);
663 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n",
664 av_err2str(res));
665 return res;
666 }
667 }
668 atomic_store(&s->buffers_queued, s->buffers);
669
670 type = s->buf_type;
671 if (v4l2_ioctl(s->fd, VIDIOC_STREAMON, &type) < 0) {
672 res = AVERROR(errno);
673 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n",
674 av_err2str(res));
675 return res;
676 }
677
678 return 0;
679 }
680
681 static void mmap_close(struct video_data *s)
682 {
683 enum v4l2_buf_type type;
684 int i;
685
686 type = s->buf_type;
687 /* We do not check for the result, because we could
688 * not do anything about it anyway...
689 */
690 v4l2_ioctl(s->fd, VIDIOC_STREAMOFF, &type);
691 for (i = 0; i < s->buffers; i++) {
692 v4l2_munmap(s->buf_start[i], s->buf_len[i]);
693 }
694 av_freep(&s->buf_start);
695 av_freep(&s->buf_len);
696 }
697
698 static int v4l2_set_parameters(AVFormatContext *ctx)
699 {
700 struct video_data *s = ctx->priv_data;
701 struct v4l2_standard standard = { 0 };
702 struct v4l2_streamparm streamparm = { 0 };
703 struct v4l2_fract *tpf;
704 AVRational framerate_q = { 0 };
705 int i, ret;
706
707 if (s->framerate &&
708 (ret = av_parse_video_rate(&framerate_q, s->framerate)) < 0) {
709 av_log(ctx, AV_LOG_ERROR, "Could not parse framerate '%s'.\n",
710 s->framerate);
711 return ret;
712 }
713
714 if (s->standard) {
715 if (s->std_id) {
716 ret = 0;
717 av_log(ctx, AV_LOG_DEBUG, "Setting standard: %s\n", s->standard);
718 /* set tv standard */
719 for (i = 0; ; i++) {
720 standard.index = i;
721 if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
722 ret = AVERROR(errno);
723 break;
724 }
725 if (!av_strcasecmp(standard.name, s->standard))
726 break;
727 }
728 if (ret < 0) {
729 av_log(ctx, AV_LOG_ERROR, "Unknown or unsupported standard '%s'\n", s->standard);
730 return ret;
731 }
732
733 if (v4l2_ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
734 ret = AVERROR(errno);
735 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_S_STD): %s\n", av_err2str(ret));
736 return ret;
737 }
738 } else {
739 av_log(ctx, AV_LOG_WARNING,
740 "This device does not support any standard\n");
741 }
742 }
743
744 /* get standard */
745 if (v4l2_ioctl(s->fd, VIDIOC_G_STD, &s->std_id) == 0) {
746 tpf = &standard.frameperiod;
747 for (i = 0; ; i++) {
748 standard.index = i;
749 if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
750 ret = AVERROR(errno);
751 if (ret == AVERROR(EINVAL)
752 #ifdef ENODATA
753 || ret == AVERROR(ENODATA)
754 #endif
755 ) {
756 tpf = &streamparm.parm.capture.timeperframe;
757 break;
758 }
759 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMSTD): %s\n", av_err2str(ret));
760 return ret;
761 }
762 if (standard.id == s->std_id) {
763 av_log(ctx, AV_LOG_DEBUG,
764 "Current standard: %s, id: %"PRIx64", frameperiod: %d/%d\n",
765 standard.name, (uint64_t)standard.id, tpf->numerator, tpf->denominator);
766 break;
767 }
768 }
769 } else {
770 tpf = &streamparm.parm.capture.timeperframe;
771 }
772
773 streamparm.type = s->buf_type;
774 if (v4l2_ioctl(s->fd, VIDIOC_G_PARM, &streamparm) < 0) {
775 ret = AVERROR(errno);
776 av_log(ctx, AV_LOG_WARNING, "ioctl(VIDIOC_G_PARM): %s\n", av_err2str(ret));
777 } else if (framerate_q.num && framerate_q.den) {
778 if (streamparm.parm.capture.capability & V4L2_CAP_TIMEPERFRAME) {
779 tpf = &streamparm.parm.capture.timeperframe;
780
781 av_log(ctx, AV_LOG_DEBUG, "Setting time per frame to %d/%d\n",
782 framerate_q.den, framerate_q.num);
783 tpf->numerator = framerate_q.den;
784 tpf->denominator = framerate_q.num;
785
786 if (v4l2_ioctl(s->fd, VIDIOC_S_PARM, &streamparm) < 0) {
787 ret = AVERROR(errno);
788 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_S_PARM): %s\n",
789 av_err2str(ret));
790 return ret;
791 }
792
793 if (framerate_q.num != tpf->denominator ||
794 framerate_q.den != tpf->numerator) {
795 av_log(ctx, AV_LOG_INFO,
796 "The driver changed the time per frame from "
797 "%d/%d to %d/%d\n",
798 framerate_q.den, framerate_q.num,
799 tpf->numerator, tpf->denominator);
800 }
801 } else {
802 av_log(ctx, AV_LOG_WARNING,
803 "The driver does not permit changing the time per frame\n");
804 }
805 }
806 if (tpf->denominator > 0 && tpf->numerator > 0) {
807 ctx->streams[0]->avg_frame_rate.num = tpf->denominator;
808 ctx->streams[0]->avg_frame_rate.den = tpf->numerator;
809 ctx->streams[0]->r_frame_rate = ctx->streams[0]->avg_frame_rate;
810 } else
811 av_log(ctx, AV_LOG_WARNING, "Time per frame unknown\n");
812
813 return 0;
814 }
815
816 static int device_try_init(AVFormatContext *ctx,
817 enum AVPixelFormat pix_fmt,
818 int *width,
819 int *height,
820 uint32_t *desired_format,
821 enum AVCodecID *codec_id)
822 {
823 int ret, i;
824
825 *desired_format = ff_fmt_ff2v4l(pix_fmt, ctx->video_codec_id);
826
827 if (*desired_format) {
828 ret = device_init(ctx, width, height, *desired_format);
829 if (ret < 0) {
830 *desired_format = 0;
831 if (ret != AVERROR(EINVAL))
832 return ret;
833 }
834 }
835
836 if (!*desired_format) {
837 for (i = 0; ff_fmt_conversion_table[i].codec_id != AV_CODEC_ID_NONE; i++) {
838 if (ctx->video_codec_id == AV_CODEC_ID_NONE ||
839 ff_fmt_conversion_table[i].codec_id == ctx->video_codec_id) {
840 av_log(ctx, AV_LOG_DEBUG, "Trying to set codec:%s pix_fmt:%s\n",
841 avcodec_get_name(ff_fmt_conversion_table[i].codec_id),
842 (char *)av_x_if_null(av_get_pix_fmt_name(ff_fmt_conversion_table[i].ff_fmt), "none"));
843
844 *desired_format = ff_fmt_conversion_table[i].v4l2_fmt;
845 ret = device_init(ctx, width, height, *desired_format);
846 if (ret >= 0)
847 break;
848 else if (ret != AVERROR(EINVAL))
849 return ret;
850 *desired_format = 0;
851 }
852 }
853
854 if (*desired_format == 0) {
855 av_log(ctx, AV_LOG_ERROR, "Cannot find a proper format for "
856 "codec '%s' (id %d), pixel format '%s' (id %d)\n",
857 avcodec_get_name(ctx->video_codec_id), ctx->video_codec_id,
858 (char *)av_x_if_null(av_get_pix_fmt_name(pix_fmt), "none"), pix_fmt);
859 ret = AVERROR(EINVAL);
860 }
861 }
862
863 *codec_id = ff_fmt_v4l2codec(*desired_format);
864 if (*codec_id == AV_CODEC_ID_NONE)
865 av_assert0(ret == AVERROR(EINVAL));
866 return ret;
867 }
868
869 3678 static int v4l2_read_probe(const AVProbeData *p)
870 {
871
1/2
✗ Branch 1 not taken.
✓ Branch 2 taken 3678 times.
3678 if (av_strstart(p->filename, "/dev/video", NULL))
872 return AVPROBE_SCORE_MAX - 1;
873 3678 return 0;
874 }
875
876 static int v4l2_read_header(AVFormatContext *ctx)
877 {
878 struct video_data *s = ctx->priv_data;
879 AVStream *st;
880 int res = 0;
881 uint32_t desired_format;
882 enum AVCodecID codec_id = AV_CODEC_ID_NONE;
883 enum AVPixelFormat pix_fmt = AV_PIX_FMT_NONE;
884 struct v4l2_input input = { 0 };
885
886 st = avformat_new_stream(ctx, NULL);
887 if (!st)
888 return AVERROR(ENOMEM);
889
890 #if CONFIG_LIBV4L2
891 /* silence libv4l2 logging. if fopen() fails v4l2_log_file will be NULL
892 and errors will get sent to stderr */
893 if (s->use_libv4l2)
894 v4l2_log_file = fopen("/dev/null", "w");
895 #endif
896
897 s->fd = device_open(ctx, ctx->url);
898 if (s->fd < 0)
899 return s->fd;
900
901 if (s->channel != -1) {
902 /* set video input */
903 av_log(ctx, AV_LOG_DEBUG, "Selecting input_channel: %d\n", s->channel);
904 if (v4l2_ioctl(s->fd, VIDIOC_S_INPUT, &s->channel) < 0) {
905 res = AVERROR(errno);
906 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_S_INPUT): %s\n", av_err2str(res));
907 goto fail;
908 }
909 } else {
910 /* get current video input */
911 if (v4l2_ioctl(s->fd, VIDIOC_G_INPUT, &s->channel) < 0) {
912 res = AVERROR(errno);
913 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_G_INPUT): %s\n", av_err2str(res));
914 goto fail;
915 }
916 }
917
918 /* enum input */
919 input.index = s->channel;
920 if (v4l2_ioctl(s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
921 res = AVERROR(errno);
922 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMINPUT): %s\n", av_err2str(res));
923 goto fail;
924 }
925 s->std_id = input.std;
926 av_log(ctx, AV_LOG_DEBUG, "Current input_channel: %d, input_name: %s, input_std: %"PRIx64"\n",
927 s->channel, input.name, (uint64_t)input.std);
928
929 if (s->list_format) {
930 list_formats(ctx, s->list_format);
931 res = AVERROR_EXIT;
932 goto fail;
933 }
934
935 if (s->list_standard) {
936 list_standards(ctx);
937 res = AVERROR_EXIT;
938 goto fail;
939 }
940
941 avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
942
943 if (s->pixel_format) {
944 const AVCodecDescriptor *desc = avcodec_descriptor_get_by_name(s->pixel_format);
945
946 if (desc)
947 ctx->video_codec_id = desc->id;
948
949 pix_fmt = av_get_pix_fmt(s->pixel_format);
950
951 if (pix_fmt == AV_PIX_FMT_NONE && !desc) {
952 av_log(ctx, AV_LOG_ERROR, "No such input format: %s.\n",
953 s->pixel_format);
954
955 res = AVERROR(EINVAL);
956 goto fail;
957 }
958 }
959
960 if (!s->width && !s->height) {
961 struct v4l2_format fmt = { .type = s->buf_type };
962
963 av_log(ctx, AV_LOG_VERBOSE,
964 "Querying the device for the current frame size\n");
965 if (v4l2_ioctl(s->fd, VIDIOC_G_FMT, &fmt) < 0) {
966 res = AVERROR(errno);
967 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n",
968 av_err2str(res));
969 goto fail;
970 }
971
972 s->width = fmt.fmt.pix.width;
973 s->height = fmt.fmt.pix.height;
974 av_log(ctx, AV_LOG_VERBOSE,
975 "Setting frame size to %dx%d\n", s->width, s->height);
976 }
977
978 res = device_try_init(ctx, pix_fmt, &s->width, &s->height, &desired_format, &codec_id);
979 if (res < 0)
980 goto fail;
981
982 /* If no pixel_format was specified, the codec_id was not known up
983 * until now. Set video_codec_id in the context, as codec_id will
984 * not be available outside this function
985 */
986 if (codec_id != AV_CODEC_ID_NONE && ctx->video_codec_id == AV_CODEC_ID_NONE)
987 ctx->video_codec_id = codec_id;
988
989 if ((res = av_image_check_size(s->width, s->height, 0, ctx)) < 0)
990 goto fail;
991
992 s->pixelformat = desired_format;
993
994 if ((res = v4l2_set_parameters(ctx)) < 0)
995 goto fail;
996
997 st->codecpar->format = ff_fmt_v4l2ff(desired_format, codec_id);
998 if (st->codecpar->format != AV_PIX_FMT_NONE)
999 s->frame_size = av_image_get_buffer_size(st->codecpar->format,
1000 s->width, s->height, 1);
1001
1002 if ((res = mmap_init(ctx)) ||
1003 (res = mmap_start(ctx)) < 0)
1004 goto fail;
1005
1006 s->top_field_first = first_field(s);
1007
1008 st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
1009 st->codecpar->codec_id = codec_id;
1010 if (codec_id == AV_CODEC_ID_RAWVIDEO)
1011 st->codecpar->codec_tag =
1012 avcodec_pix_fmt_to_codec_tag(st->codecpar->format);
1013 else if (codec_id == AV_CODEC_ID_H264) {
1014 avpriv_stream_set_need_parsing(st, AVSTREAM_PARSE_FULL_ONCE);
1015 }
1016 if (desired_format == V4L2_PIX_FMT_YVU420)
1017 st->codecpar->codec_tag = MKTAG('Y', 'V', '1', '2');
1018 else if (desired_format == V4L2_PIX_FMT_YVU410)
1019 st->codecpar->codec_tag = MKTAG('Y', 'V', 'U', '9');
1020 st->codecpar->width = s->width;
1021 st->codecpar->height = s->height;
1022 if (st->avg_frame_rate.den)
1023 st->codecpar->bit_rate = s->frame_size * av_q2d(st->avg_frame_rate) * 8;
1024
1025 return 0;
1026
1027 fail:
1028 v4l2_close(s->fd);
1029 return res;
1030 }
1031
1032 static int v4l2_read_packet(AVFormatContext *ctx, AVPacket *pkt)
1033 {
1034 int res;
1035
1036 if ((res = mmap_read_frame(ctx, pkt)) < 0) {
1037 return res;
1038 }
1039
1040 return pkt->size;
1041 }
1042
1043 static int v4l2_read_close(AVFormatContext *ctx)
1044 {
1045 struct video_data *s = ctx->priv_data;
1046
1047 if (atomic_load(&s->buffers_queued) != s->buffers)
1048 av_log(ctx, AV_LOG_WARNING, "Some buffers are still owned by the caller on "
1049 "close.\n");
1050
1051 mmap_close(s);
1052
1053 ff_timefilter_destroy(s->timefilter);
1054 v4l2_close(s->fd);
1055 return 0;
1056 }
1057
1058 static int v4l2_is_v4l_dev(const char *name)
1059 {
1060 return !strncmp(name, "video", 5) ||
1061 !strncmp(name, "radio", 5) ||
1062 !strncmp(name, "vbi", 3) ||
1063 !strncmp(name, "v4l-subdev", 10);
1064 }
1065
1066 static int v4l2_get_device_list(AVFormatContext *ctx, AVDeviceInfoList *device_list)
1067 {
1068 struct video_data *s = ctx->priv_data;
1069 DIR *dir;
1070 struct dirent *entry;
1071 int ret = 0;
1072
1073 if (!device_list)
1074 return AVERROR(EINVAL);
1075
1076 dir = opendir("/dev");
1077 if (!dir) {
1078 ret = AVERROR(errno);
1079 av_log(ctx, AV_LOG_ERROR, "Couldn't open the directory: %s\n", av_err2str(ret));
1080 return ret;
1081 }
1082 while ((entry = readdir(dir))) {
1083 AVDeviceInfo *device = NULL;
1084 struct v4l2_capability cap;
1085 int fd = -1, size;
1086 char device_name[256];
1087
1088 if (!v4l2_is_v4l_dev(entry->d_name))
1089 continue;
1090
1091 size = snprintf(device_name, sizeof(device_name), "/dev/%s", entry->d_name);
1092 if (size >= sizeof(device_name)) {
1093 av_log(ctx, AV_LOG_ERROR, "Device name too long.\n");
1094 ret = AVERROR(ENOSYS);
1095 break;
1096 }
1097
1098 if ((fd = device_open(ctx, device_name)) < 0)
1099 continue;
1100
1101 if (v4l2_ioctl(fd, VIDIOC_QUERYCAP, &cap) < 0) {
1102 ret = AVERROR(errno);
1103 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n", av_err2str(ret));
1104 goto fail;
1105 }
1106
1107 device = av_mallocz(sizeof(AVDeviceInfo));
1108 if (!device) {
1109 ret = AVERROR(ENOMEM);
1110 goto fail;
1111 }
1112 device->device_name = av_strdup(device_name);
1113 device->device_description = av_strdup(cap.card);
1114 if (!device->device_name || !device->device_description) {
1115 ret = AVERROR(ENOMEM);
1116 goto fail;
1117 }
1118
1119 if ((ret = av_dynarray_add_nofree(&device_list->devices,
1120 &device_list->nb_devices, device)) < 0)
1121 goto fail;
1122
1123 v4l2_close(fd);
1124 continue;
1125
1126 fail:
1127 if (device) {
1128 av_freep(&device->device_name);
1129 av_freep(&device->device_description);
1130 av_freep(&device);
1131 }
1132 v4l2_close(fd);
1133 break;
1134 }
1135 closedir(dir);
1136 return ret;
1137 }
1138
1139 #define OFFSET(x) offsetof(struct video_data, x)
1140 #define DEC AV_OPT_FLAG_DECODING_PARAM
1141
1142 static const AVOption options[] = {
1143 { "standard", "set TV standard, used only by analog frame grabber", OFFSET(standard), AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, DEC },
1144 { "channel", "set TV channel, used only by frame grabber", OFFSET(channel), AV_OPT_TYPE_INT, {.i64 = -1 }, -1, INT_MAX, DEC },
1145 { "video_size", "set frame size", OFFSET(width), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, DEC },
1146 { "pixel_format", "set preferred pixel format", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
1147 { "input_format", "set preferred pixel format (for raw video) or codec name", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
1148 { "framerate", "set frame rate", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
1149
1150 { "list_formats", "list available formats and exit", OFFSET(list_format), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, DEC, .unit = "list_formats" },
1151 { "all", "show all available formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_ALLFORMATS }, 0, INT_MAX, DEC, .unit = "list_formats" },
1152 { "raw", "show only non-compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_RAWFORMATS }, 0, INT_MAX, DEC, .unit = "list_formats" },
1153 { "compressed", "show only compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_COMPFORMATS }, 0, INT_MAX, DEC, .unit = "list_formats" },
1154
1155 { "list_standards", "list supported standards and exit", OFFSET(list_standard), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 1, DEC, .unit = "list_standards" },
1156 { "all", "show all supported standards", OFFSET(list_standard), AV_OPT_TYPE_CONST, {.i64 = 1 }, 0, 0, DEC, .unit = "list_standards" },
1157
1158 { "timestamps", "set type of timestamps for grabbed frames", OFFSET(ts_mode), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 2, DEC, .unit = "timestamps" },
1159 { "ts", "set type of timestamps for grabbed frames", OFFSET(ts_mode), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 2, DEC, .unit = "timestamps" },
1160 { "default", "use timestamps from the kernel", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.i64 = V4L_TS_DEFAULT }, 0, 2, DEC, .unit = "timestamps" },
1161 { "abs", "use absolute timestamps (wall clock)", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.i64 = V4L_TS_ABS }, 0, 2, DEC, .unit = "timestamps" },
1162 { "mono2abs", "force conversion from monotonic to absolute timestamps", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.i64 = V4L_TS_MONO2ABS }, 0, 2, DEC, .unit = "timestamps" },
1163 { "use_libv4l2", "use libv4l2 (v4l-utils) conversion functions", OFFSET(use_libv4l2), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, DEC },
1164 { NULL },
1165 };
1166
1167 static const AVClass v4l2_class = {
1168 .class_name = "V4L2 indev",
1169 .item_name = av_default_item_name,
1170 .option = options,
1171 .version = LIBAVUTIL_VERSION_INT,
1172 .category = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
1173 };
1174
1175 const FFInputFormat ff_v4l2_demuxer = {
1176 .p.name = "video4linux2,v4l2",
1177 .p.long_name = NULL_IF_CONFIG_SMALL("Video4Linux2 device grab"),
1178 .p.flags = AVFMT_NOFILE,
1179 .p.priv_class = &v4l2_class,
1180 .priv_data_size = sizeof(struct video_data),
1181 .read_probe = v4l2_read_probe,
1182 .read_header = v4l2_read_header,
1183 .read_packet = v4l2_read_packet,
1184 .read_close = v4l2_read_close,
1185 .get_device_list = v4l2_get_device_list,
1186 };
1187