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path: root/libavdevice/v4l2.c (plain)
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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
42static 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
70struct 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 int (*ioctl_f)(int fd, unsigned long int request, ...);
99 ssize_t (*read_f)(int fd, void *buffer, size_t n);
100 void *(*mmap_f)(void *start, size_t length, int prot, int flags, int fd, int64_t offset);
101 int (*munmap_f)(void *_start, size_t length);
102};
103
104struct buff_data {
105 struct video_data *s;
106 int index;
107};
108
109static int device_open(AVFormatContext *ctx)
110{
111 struct video_data *s = ctx->priv_data;
112 struct v4l2_capability cap;
113 int fd;
114 int err;
115 int flags = O_RDWR;
116
117#define SET_WRAPPERS(prefix) do { \
118 s->open_f = prefix ## open; \
119 s->close_f = prefix ## close; \
120 s->dup_f = prefix ## dup; \
121 s->ioctl_f = prefix ## ioctl; \
122 s->read_f = prefix ## read; \
123 s->mmap_f = prefix ## mmap; \
124 s->munmap_f = prefix ## munmap; \
125} while (0)
126
127 if (s->use_libv4l2) {
128#if CONFIG_LIBV4L2
129 SET_WRAPPERS(v4l2_);
130#else
131 av_log(ctx, AV_LOG_ERROR, "libavdevice is not built with libv4l2 support.\n");
132 return AVERROR(EINVAL);
133#endif
134 } else {
135 SET_WRAPPERS();
136 }
137
138#define v4l2_open s->open_f
139#define v4l2_close s->close_f
140#define v4l2_dup s->dup_f
141#define v4l2_ioctl s->ioctl_f
142#define v4l2_read s->read_f
143#define v4l2_mmap s->mmap_f
144#define v4l2_munmap s->munmap_f
145
146 if (ctx->flags & AVFMT_FLAG_NONBLOCK) {
147 flags |= O_NONBLOCK;
148 }
149
150 fd = v4l2_open(ctx->filename, flags, 0);
151 if (fd < 0) {
152 err = AVERROR(errno);
153 av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s: %s\n",
154 ctx->filename, av_err2str(err));
155 return err;
156 }
157
158 if (v4l2_ioctl(fd, VIDIOC_QUERYCAP, &cap) < 0) {
159 err = AVERROR(errno);
160 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
161 av_err2str(err));
162 goto fail;
163 }
164
165 av_log(ctx, AV_LOG_VERBOSE, "fd:%d capabilities:%x\n",
166 fd, cap.capabilities);
167
168 if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {
169 av_log(ctx, AV_LOG_ERROR, "Not a video capture device.\n");
170 err = AVERROR(ENODEV);
171 goto fail;
172 }
173
174 if (!(cap.capabilities & V4L2_CAP_STREAMING)) {
175 av_log(ctx, AV_LOG_ERROR,
176 "The device does not support the streaming I/O method.\n");
177 err = AVERROR(ENOSYS);
178 goto fail;
179 }
180
181 return fd;
182
183fail:
184 v4l2_close(fd);
185 return err;
186}
187
188static int device_init(AVFormatContext *ctx, int *width, int *height,
189 uint32_t pixelformat)
190{
191 struct video_data *s = ctx->priv_data;
192 struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
193 int res = 0;
194
195 fmt.fmt.pix.width = *width;
196 fmt.fmt.pix.height = *height;
197 fmt.fmt.pix.pixelformat = pixelformat;
198 fmt.fmt.pix.field = V4L2_FIELD_ANY;
199
200 /* Some drivers will fail and return EINVAL when the pixelformat
201 is not supported (even if type field is valid and supported) */
202 if (v4l2_ioctl(s->fd, VIDIOC_S_FMT, &fmt) < 0)
203 res = AVERROR(errno);
204
205 if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {
206 av_log(ctx, AV_LOG_INFO,
207 "The V4L2 driver changed the video from %dx%d to %dx%d\n",
208 *width, *height, fmt.fmt.pix.width, fmt.fmt.pix.height);
209 *width = fmt.fmt.pix.width;
210 *height = fmt.fmt.pix.height;
211 }
212
213 if (pixelformat != fmt.fmt.pix.pixelformat) {
214 av_log(ctx, AV_LOG_DEBUG,
215 "The V4L2 driver changed the pixel format "
216 "from 0x%08X to 0x%08X\n",
217 pixelformat, fmt.fmt.pix.pixelformat);
218 res = AVERROR(EINVAL);
219 }
220
221 if (fmt.fmt.pix.field == V4L2_FIELD_INTERLACED) {
222 av_log(ctx, AV_LOG_DEBUG,
223 "The V4L2 driver is using the interlaced mode\n");
224 s->interlaced = 1;
225 }
226
227 return res;
228}
229
230static int first_field(const struct video_data *s)
231{
232 int res;
233 v4l2_std_id std;
234
235 res = v4l2_ioctl(s->fd, VIDIOC_G_STD, &std);
236 if (res < 0)
237 return 0;
238 if (std & V4L2_STD_NTSC)
239 return 0;
240
241 return 1;
242}
243
244#if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
245static void list_framesizes(AVFormatContext *ctx, uint32_t pixelformat)
246{
247 const struct video_data *s = ctx->priv_data;
248 struct v4l2_frmsizeenum vfse = { .pixel_format = pixelformat };
249
250 while(!v4l2_ioctl(s->fd, VIDIOC_ENUM_FRAMESIZES, &vfse)) {
251 switch (vfse.type) {
252 case V4L2_FRMSIZE_TYPE_DISCRETE:
253 av_log(ctx, AV_LOG_INFO, " %ux%u",
254 vfse.discrete.width, vfse.discrete.height);
255 break;
256 case V4L2_FRMSIZE_TYPE_CONTINUOUS:
257 case V4L2_FRMSIZE_TYPE_STEPWISE:
258 av_log(ctx, AV_LOG_INFO, " {%u-%u, %u}x{%u-%u, %u}",
259 vfse.stepwise.min_width,
260 vfse.stepwise.max_width,
261 vfse.stepwise.step_width,
262 vfse.stepwise.min_height,
263 vfse.stepwise.max_height,
264 vfse.stepwise.step_height);
265 }
266 vfse.index++;
267 }
268}
269#endif
270
271static void list_formats(AVFormatContext *ctx, int type)
272{
273 const struct video_data *s = ctx->priv_data;
274 struct v4l2_fmtdesc vfd = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
275
276 while(!v4l2_ioctl(s->fd, VIDIOC_ENUM_FMT, &vfd)) {
277 enum AVCodecID codec_id = ff_fmt_v4l2codec(vfd.pixelformat);
278 enum AVPixelFormat pix_fmt = ff_fmt_v4l2ff(vfd.pixelformat, codec_id);
279
280 vfd.index++;
281
282 if (!(vfd.flags & V4L2_FMT_FLAG_COMPRESSED) &&
283 type & V4L_RAWFORMATS) {
284 const char *fmt_name = av_get_pix_fmt_name(pix_fmt);
285 av_log(ctx, AV_LOG_INFO, "Raw : %11s : %20s :",
286 fmt_name ? fmt_name : "Unsupported",
287 vfd.description);
288 } else if (vfd.flags & V4L2_FMT_FLAG_COMPRESSED &&
289 type & V4L_COMPFORMATS) {
290 const AVCodecDescriptor *desc = avcodec_descriptor_get(codec_id);
291 av_log(ctx, AV_LOG_INFO, "Compressed: %11s : %20s :",
292 desc ? desc->name : "Unsupported",
293 vfd.description);
294 } else {
295 continue;
296 }
297
298#ifdef V4L2_FMT_FLAG_EMULATED
299 if (vfd.flags & V4L2_FMT_FLAG_EMULATED)
300 av_log(ctx, AV_LOG_INFO, " Emulated :");
301#endif
302#if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
303 list_framesizes(ctx, vfd.pixelformat);
304#endif
305 av_log(ctx, AV_LOG_INFO, "\n");
306 }
307}
308
309static void list_standards(AVFormatContext *ctx)
310{
311 int ret;
312 struct video_data *s = ctx->priv_data;
313 struct v4l2_standard standard;
314
315 if (s->std_id == 0)
316 return;
317
318 for (standard.index = 0; ; standard.index++) {
319 if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
320 ret = AVERROR(errno);
321 if (ret == AVERROR(EINVAL)) {
322 break;
323 } else {
324 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMSTD): %s\n", av_err2str(ret));
325 return;
326 }
327 }
328 av_log(ctx, AV_LOG_INFO, "%2d, %16"PRIx64", %s\n",
329 standard.index, (uint64_t)standard.id, standard.name);
330 }
331}
332
333static int mmap_init(AVFormatContext *ctx)
334{
335 int i, res;
336 struct video_data *s = ctx->priv_data;
337 struct v4l2_requestbuffers req = {
338 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
339 .count = desired_video_buffers,
340 .memory = V4L2_MEMORY_MMAP
341 };
342
343 if (v4l2_ioctl(s->fd, VIDIOC_REQBUFS, &req) < 0) {
344 res = AVERROR(errno);
345 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS): %s\n", av_err2str(res));
346 return res;
347 }
348
349 if (req.count < 2) {
350 av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");
351 return AVERROR(ENOMEM);
352 }
353 s->buffers = req.count;
354 s->buf_start = av_malloc_array(s->buffers, sizeof(void *));
355 if (!s->buf_start) {
356 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
357 return AVERROR(ENOMEM);
358 }
359 s->buf_len = av_malloc_array(s->buffers, sizeof(unsigned int));
360 if (!s->buf_len) {
361 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
362 av_freep(&s->buf_start);
363 return AVERROR(ENOMEM);
364 }
365
366 for (i = 0; i < req.count; i++) {
367 struct v4l2_buffer buf = {
368 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
369 .index = i,
370 .memory = V4L2_MEMORY_MMAP
371 };
372 if (v4l2_ioctl(s->fd, VIDIOC_QUERYBUF, &buf) < 0) {
373 res = AVERROR(errno);
374 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF): %s\n", av_err2str(res));
375 return res;
376 }
377
378 s->buf_len[i] = buf.length;
379 if (s->frame_size > 0 && s->buf_len[i] < s->frame_size) {
380 av_log(ctx, AV_LOG_ERROR,
381 "buf_len[%d] = %d < expected frame size %d\n",
382 i, s->buf_len[i], s->frame_size);
383 return AVERROR(ENOMEM);
384 }
385 s->buf_start[i] = v4l2_mmap(NULL, buf.length,
386 PROT_READ | PROT_WRITE, MAP_SHARED,
387 s->fd, buf.m.offset);
388
389 if (s->buf_start[i] == MAP_FAILED) {
390 res = AVERROR(errno);
391 av_log(ctx, AV_LOG_ERROR, "mmap: %s\n", av_err2str(res));
392 return res;
393 }
394 }
395
396 return 0;
397}
398
399static int enqueue_buffer(struct video_data *s, struct v4l2_buffer *buf)
400{
401 int res = 0;
402
403 if (v4l2_ioctl(s->fd, VIDIOC_QBUF, buf) < 0) {
404 res = AVERROR(errno);
405 av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", av_err2str(res));
406 } else {
407 atomic_fetch_add(&s->buffers_queued, 1);
408 }
409
410 return res;
411}
412
413static void mmap_release_buffer(void *opaque, uint8_t *data)
414{
415 struct v4l2_buffer buf = { 0 };
416 struct buff_data *buf_descriptor = opaque;
417 struct video_data *s = buf_descriptor->s;
418
419 buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
420 buf.memory = V4L2_MEMORY_MMAP;
421 buf.index = buf_descriptor->index;
422 av_free(buf_descriptor);
423
424 enqueue_buffer(s, &buf);
425}
426
427#if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
428static int64_t av_gettime_monotonic(void)
429{
430 return av_gettime_relative();
431}
432#endif
433
434static int init_convert_timestamp(AVFormatContext *ctx, int64_t ts)
435{
436 struct video_data *s = ctx->priv_data;
437 int64_t now;
438
439 now = av_gettime();
440 if (s->ts_mode == V4L_TS_ABS &&
441 ts <= now + 1 * AV_TIME_BASE && ts >= now - 10 * AV_TIME_BASE) {
442 av_log(ctx, AV_LOG_INFO, "Detected absolute timestamps\n");
443 s->ts_mode = V4L_TS_CONVERT_READY;
444 return 0;
445 }
446#if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
447 if (ctx->streams[0]->avg_frame_rate.num) {
448 now = av_gettime_monotonic();
449 if (s->ts_mode == V4L_TS_MONO2ABS ||
450 (ts <= now + 1 * AV_TIME_BASE && ts >= now - 10 * AV_TIME_BASE)) {
451 AVRational tb = {AV_TIME_BASE, 1};
452 int64_t period = av_rescale_q(1, tb, ctx->streams[0]->avg_frame_rate);
453 av_log(ctx, AV_LOG_INFO, "Detected monotonic timestamps, converting\n");
454 /* microseconds instead of seconds, MHz instead of Hz */
455 s->timefilter = ff_timefilter_new(1, period, 1.0E-6);
456 if (!s->timefilter)
457 return AVERROR(ENOMEM);
458 s->ts_mode = V4L_TS_CONVERT_READY;
459 return 0;
460 }
461 }
462#endif
463 av_log(ctx, AV_LOG_ERROR, "Unknown timestamps\n");
464 return AVERROR(EIO);
465}
466
467static int convert_timestamp(AVFormatContext *ctx, int64_t *ts)
468{
469 struct video_data *s = ctx->priv_data;
470
471 if (s->ts_mode) {
472 int r = init_convert_timestamp(ctx, *ts);
473 if (r < 0)
474 return r;
475 }
476#if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
477 if (s->timefilter) {
478 int64_t nowa = av_gettime();
479 int64_t nowm = av_gettime_monotonic();
480 ff_timefilter_update(s->timefilter, nowa, nowm - s->last_time_m);
481 s->last_time_m = nowm;
482 *ts = ff_timefilter_eval(s->timefilter, *ts - nowm);
483 }
484#endif
485 return 0;
486}
487
488static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
489{
490 struct video_data *s = ctx->priv_data;
491 struct v4l2_buffer buf = {
492 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
493 .memory = V4L2_MEMORY_MMAP
494 };
495 int res;
496
497 pkt->size = 0;
498
499 /* FIXME: Some special treatment might be needed in case of loss of signal... */
500 while ((res = v4l2_ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 && (errno == EINTR));
501 if (res < 0) {
502 if (errno == EAGAIN)
503 return AVERROR(EAGAIN);
504
505 res = AVERROR(errno);
506 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n",
507 av_err2str(res));
508 return res;
509 }
510
511 if (buf.index >= s->buffers) {
512 av_log(ctx, AV_LOG_ERROR, "Invalid buffer index received.\n");
513 return AVERROR(EINVAL);
514 }
515 atomic_fetch_add(&s->buffers_queued, -1);
516 // always keep at least one buffer queued
517 av_assert0(atomic_load(&s->buffers_queued) >= 1);
518
519#ifdef V4L2_BUF_FLAG_ERROR
520 if (buf.flags & V4L2_BUF_FLAG_ERROR) {
521 av_log(ctx, AV_LOG_WARNING,
522 "Dequeued v4l2 buffer contains corrupted data (%d bytes).\n",
523 buf.bytesused);
524 buf.bytesused = 0;
525 } else
526#endif
527 {
528 /* CPIA is a compressed format and we don't know the exact number of bytes
529 * used by a frame, so set it here as the driver announces it. */
530 if (ctx->video_codec_id == AV_CODEC_ID_CPIA)
531 s->frame_size = buf.bytesused;
532
533 if (s->frame_size > 0 && buf.bytesused != s->frame_size) {
534 av_log(ctx, AV_LOG_ERROR,
535 "Dequeued v4l2 buffer contains %d bytes, but %d were expected. Flags: 0x%08X.\n",
536 buf.bytesused, s->frame_size, buf.flags);
537 enqueue_buffer(s, &buf);
538 return AVERROR_INVALIDDATA;
539 }
540 }
541
542 /* Image is at s->buff_start[buf.index] */
543 if (atomic_load(&s->buffers_queued) == FFMAX(s->buffers / 8, 1)) {
544 /* when we start getting low on queued buffers, fall back on copying data */
545 res = av_new_packet(pkt, buf.bytesused);
546 if (res < 0) {
547 av_log(ctx, AV_LOG_ERROR, "Error allocating a packet.\n");
548 enqueue_buffer(s, &buf);
549 return res;
550 }
551 memcpy(pkt->data, s->buf_start[buf.index], buf.bytesused);
552
553 res = enqueue_buffer(s, &buf);
554 if (res) {
555 av_packet_unref(pkt);
556 return res;
557 }
558 } else {
559 struct buff_data *buf_descriptor;
560
561 pkt->data = s->buf_start[buf.index];
562 pkt->size = buf.bytesused;
563
564 buf_descriptor = av_malloc(sizeof(struct buff_data));
565 if (!buf_descriptor) {
566 /* Something went wrong... Since av_malloc() failed, we cannot even
567 * allocate a buffer for memcpying into it
568 */
569 av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
570 enqueue_buffer(s, &buf);
571
572 return AVERROR(ENOMEM);
573 }
574 buf_descriptor->index = buf.index;
575 buf_descriptor->s = s;
576
577 pkt->buf = av_buffer_create(pkt->data, pkt->size, mmap_release_buffer,
578 buf_descriptor, 0);
579 if (!pkt->buf) {
580 av_log(ctx, AV_LOG_ERROR, "Failed to create a buffer\n");
581 enqueue_buffer(s, &buf);
582 av_freep(&buf_descriptor);
583 return AVERROR(ENOMEM);
584 }
585 }
586 pkt->pts = buf.timestamp.tv_sec * INT64_C(1000000) + buf.timestamp.tv_usec;
587 convert_timestamp(ctx, &pkt->pts);
588
589 return pkt->size;
590}
591
592static int mmap_start(AVFormatContext *ctx)
593{
594 struct video_data *s = ctx->priv_data;
595 enum v4l2_buf_type type;
596 int i, res;
597
598 for (i = 0; i < s->buffers; i++) {
599 struct v4l2_buffer buf = {
600 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
601 .index = i,
602 .memory = V4L2_MEMORY_MMAP
603 };
604
605 if (v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf) < 0) {
606 res = AVERROR(errno);
607 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n",
608 av_err2str(res));
609 return res;
610 }
611 }
612 atomic_store(&s->buffers_queued, s->buffers);
613
614 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
615 if (v4l2_ioctl(s->fd, VIDIOC_STREAMON, &type) < 0) {
616 res = AVERROR(errno);
617 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n",
618 av_err2str(res));
619 return res;
620 }
621
622 return 0;
623}
624
625static void mmap_close(struct video_data *s)
626{
627 enum v4l2_buf_type type;
628 int i;
629
630 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
631 /* We do not check for the result, because we could
632 * not do anything about it anyway...
633 */
634 v4l2_ioctl(s->fd, VIDIOC_STREAMOFF, &type);
635 for (i = 0; i < s->buffers; i++) {
636 v4l2_munmap(s->buf_start[i], s->buf_len[i]);
637 }
638 av_freep(&s->buf_start);
639 av_freep(&s->buf_len);
640}
641
642static int v4l2_set_parameters(AVFormatContext *ctx)
643{
644 struct video_data *s = ctx->priv_data;
645 struct v4l2_standard standard = { 0 };
646 struct v4l2_streamparm streamparm = { 0 };
647 struct v4l2_fract *tpf;
648 AVRational framerate_q = { 0 };
649 int i, ret;
650
651 if (s->framerate &&
652 (ret = av_parse_video_rate(&framerate_q, s->framerate)) < 0) {
653 av_log(ctx, AV_LOG_ERROR, "Could not parse framerate '%s'.\n",
654 s->framerate);
655 return ret;
656 }
657
658 if (s->standard) {
659 if (s->std_id) {
660 ret = 0;
661 av_log(ctx, AV_LOG_DEBUG, "Setting standard: %s\n", s->standard);
662 /* set tv standard */
663 for (i = 0; ; i++) {
664 standard.index = i;
665 if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
666 ret = AVERROR(errno);
667 break;
668 }
669 if (!av_strcasecmp(standard.name, s->standard))
670 break;
671 }
672 if (ret < 0) {
673 av_log(ctx, AV_LOG_ERROR, "Unknown or unsupported standard '%s'\n", s->standard);
674 return ret;
675 }
676
677 if (v4l2_ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
678 ret = AVERROR(errno);
679 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_S_STD): %s\n", av_err2str(ret));
680 return ret;
681 }
682 } else {
683 av_log(ctx, AV_LOG_WARNING,
684 "This device does not support any standard\n");
685 }
686 }
687
688 /* get standard */
689 if (v4l2_ioctl(s->fd, VIDIOC_G_STD, &s->std_id) == 0) {
690 tpf = &standard.frameperiod;
691 for (i = 0; ; i++) {
692 standard.index = i;
693 if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
694 ret = AVERROR(errno);
695 if (ret == AVERROR(EINVAL)
696#ifdef ENODATA
697 || ret == AVERROR(ENODATA)
698#endif
699 ) {
700 tpf = &streamparm.parm.capture.timeperframe;
701 break;
702 }
703 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMSTD): %s\n", av_err2str(ret));
704 return ret;
705 }
706 if (standard.id == s->std_id) {
707 av_log(ctx, AV_LOG_DEBUG,
708 "Current standard: %s, id: %"PRIx64", frameperiod: %d/%d\n",
709 standard.name, (uint64_t)standard.id, tpf->numerator, tpf->denominator);
710 break;
711 }
712 }
713 } else {
714 tpf = &streamparm.parm.capture.timeperframe;
715 }
716
717 streamparm.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
718 if (v4l2_ioctl(s->fd, VIDIOC_G_PARM, &streamparm) < 0) {
719 ret = AVERROR(errno);
720 av_log(ctx, AV_LOG_WARNING, "ioctl(VIDIOC_G_PARM): %s\n", av_err2str(ret));
721 } else if (framerate_q.num && framerate_q.den) {
722 if (streamparm.parm.capture.capability & V4L2_CAP_TIMEPERFRAME) {
723 tpf = &streamparm.parm.capture.timeperframe;
724
725 av_log(ctx, AV_LOG_DEBUG, "Setting time per frame to %d/%d\n",
726 framerate_q.den, framerate_q.num);
727 tpf->numerator = framerate_q.den;
728 tpf->denominator = framerate_q.num;
729
730 if (v4l2_ioctl(s->fd, VIDIOC_S_PARM, &streamparm) < 0) {
731 ret = AVERROR(errno);
732 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_S_PARM): %s\n",
733 av_err2str(ret));
734 return ret;
735 }
736
737 if (framerate_q.num != tpf->denominator ||
738 framerate_q.den != tpf->numerator) {
739 av_log(ctx, AV_LOG_INFO,
740 "The driver changed the time per frame from "
741 "%d/%d to %d/%d\n",
742 framerate_q.den, framerate_q.num,
743 tpf->numerator, tpf->denominator);
744 }
745 } else {
746 av_log(ctx, AV_LOG_WARNING,
747 "The driver does not permit changing the time per frame\n");
748 }
749 }
750 if (tpf->denominator > 0 && tpf->numerator > 0) {
751 ctx->streams[0]->avg_frame_rate.num = tpf->denominator;
752 ctx->streams[0]->avg_frame_rate.den = tpf->numerator;
753 ctx->streams[0]->r_frame_rate = ctx->streams[0]->avg_frame_rate;
754 } else
755 av_log(ctx, AV_LOG_WARNING, "Time per frame unknown\n");
756
757 return 0;
758}
759
760static int device_try_init(AVFormatContext *ctx,
761 enum AVPixelFormat pix_fmt,
762 int *width,
763 int *height,
764 uint32_t *desired_format,
765 enum AVCodecID *codec_id)
766{
767 int ret, i;
768
769 *desired_format = ff_fmt_ff2v4l(pix_fmt, ctx->video_codec_id);
770
771 if (*desired_format) {
772 ret = device_init(ctx, width, height, *desired_format);
773 if (ret < 0) {
774 *desired_format = 0;
775 if (ret != AVERROR(EINVAL))
776 return ret;
777 }
778 }
779
780 if (!*desired_format) {
781 for (i = 0; ff_fmt_conversion_table[i].codec_id != AV_CODEC_ID_NONE; i++) {
782 if (ctx->video_codec_id == AV_CODEC_ID_NONE ||
783 ff_fmt_conversion_table[i].codec_id == ctx->video_codec_id) {
784 av_log(ctx, AV_LOG_DEBUG, "Trying to set codec:%s pix_fmt:%s\n",
785 avcodec_get_name(ff_fmt_conversion_table[i].codec_id),
786 (char *)av_x_if_null(av_get_pix_fmt_name(ff_fmt_conversion_table[i].ff_fmt), "none"));
787
788 *desired_format = ff_fmt_conversion_table[i].v4l2_fmt;
789 ret = device_init(ctx, width, height, *desired_format);
790 if (ret >= 0)
791 break;
792 else if (ret != AVERROR(EINVAL))
793 return ret;
794 *desired_format = 0;
795 }
796 }
797
798 if (*desired_format == 0) {
799 av_log(ctx, AV_LOG_ERROR, "Cannot find a proper format for "
800 "codec '%s' (id %d), pixel format '%s' (id %d)\n",
801 avcodec_get_name(ctx->video_codec_id), ctx->video_codec_id,
802 (char *)av_x_if_null(av_get_pix_fmt_name(pix_fmt), "none"), pix_fmt);
803 ret = AVERROR(EINVAL);
804 }
805 }
806
807 *codec_id = ff_fmt_v4l2codec(*desired_format);
808 av_assert0(*codec_id != AV_CODEC_ID_NONE);
809 return ret;
810}
811
812static int v4l2_read_probe(AVProbeData *p)
813{
814 if (av_strstart(p->filename, "/dev/video", NULL))
815 return AVPROBE_SCORE_MAX - 1;
816 return 0;
817}
818
819static int v4l2_read_header(AVFormatContext *ctx)
820{
821 struct video_data *s = ctx->priv_data;
822 AVStream *st;
823 int res = 0;
824 uint32_t desired_format;
825 enum AVCodecID codec_id = AV_CODEC_ID_NONE;
826 enum AVPixelFormat pix_fmt = AV_PIX_FMT_NONE;
827 struct v4l2_input input = { 0 };
828
829 st = avformat_new_stream(ctx, NULL);
830 if (!st)
831 return AVERROR(ENOMEM);
832
833#if CONFIG_LIBV4L2
834 /* silence libv4l2 logging. if fopen() fails v4l2_log_file will be NULL
835 and errors will get sent to stderr */
836 if (s->use_libv4l2)
837 v4l2_log_file = fopen("/dev/null", "w");
838#endif
839
840 s->fd = device_open(ctx);
841 if (s->fd < 0)
842 return s->fd;
843
844 if (s->channel != -1) {
845 /* set video input */
846 av_log(ctx, AV_LOG_DEBUG, "Selecting input_channel: %d\n", s->channel);
847 if (v4l2_ioctl(s->fd, VIDIOC_S_INPUT, &s->channel) < 0) {
848 res = AVERROR(errno);
849 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_S_INPUT): %s\n", av_err2str(res));
850 goto fail;
851 }
852 } else {
853 /* get current video input */
854 if (v4l2_ioctl(s->fd, VIDIOC_G_INPUT, &s->channel) < 0) {
855 res = AVERROR(errno);
856 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_G_INPUT): %s\n", av_err2str(res));
857 goto fail;
858 }
859 }
860
861 /* enum input */
862 input.index = s->channel;
863 if (v4l2_ioctl(s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
864 res = AVERROR(errno);
865 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMINPUT): %s\n", av_err2str(res));
866 goto fail;
867 }
868 s->std_id = input.std;
869 av_log(ctx, AV_LOG_DEBUG, "Current input_channel: %d, input_name: %s, input_std: %"PRIx64"\n",
870 s->channel, input.name, (uint64_t)input.std);
871
872 if (s->list_format) {
873 list_formats(ctx, s->list_format);
874 res = AVERROR_EXIT;
875 goto fail;
876 }
877
878 if (s->list_standard) {
879 list_standards(ctx);
880 res = AVERROR_EXIT;
881 goto fail;
882 }
883
884 avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
885
886 if (s->pixel_format) {
887 AVCodec *codec = avcodec_find_decoder_by_name(s->pixel_format);
888
889 if (codec)
890 ctx->video_codec_id = codec->id;
891
892 pix_fmt = av_get_pix_fmt(s->pixel_format);
893
894 if (pix_fmt == AV_PIX_FMT_NONE && !codec) {
895 av_log(ctx, AV_LOG_ERROR, "No such input format: %s.\n",
896 s->pixel_format);
897
898 res = AVERROR(EINVAL);
899 goto fail;
900 }
901 }
902
903 if (!s->width && !s->height) {
904 struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
905
906 av_log(ctx, AV_LOG_VERBOSE,
907 "Querying the device for the current frame size\n");
908 if (v4l2_ioctl(s->fd, VIDIOC_G_FMT, &fmt) < 0) {
909 res = AVERROR(errno);
910 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n",
911 av_err2str(res));
912 goto fail;
913 }
914
915 s->width = fmt.fmt.pix.width;
916 s->height = fmt.fmt.pix.height;
917 av_log(ctx, AV_LOG_VERBOSE,
918 "Setting frame size to %dx%d\n", s->width, s->height);
919 }
920
921 res = device_try_init(ctx, pix_fmt, &s->width, &s->height, &desired_format, &codec_id);
922 if (res < 0)
923 goto fail;
924
925 /* If no pixel_format was specified, the codec_id was not known up
926 * until now. Set video_codec_id in the context, as codec_id will
927 * not be available outside this function
928 */
929 if (codec_id != AV_CODEC_ID_NONE && ctx->video_codec_id == AV_CODEC_ID_NONE)
930 ctx->video_codec_id = codec_id;
931
932 if ((res = av_image_check_size(s->width, s->height, 0, ctx)) < 0)
933 goto fail;
934
935 s->pixelformat = desired_format;
936
937 if ((res = v4l2_set_parameters(ctx)) < 0)
938 goto fail;
939
940 st->codecpar->format = ff_fmt_v4l2ff(desired_format, codec_id);
941 if (st->codecpar->format != AV_PIX_FMT_NONE)
942 s->frame_size = av_image_get_buffer_size(st->codecpar->format,
943 s->width, s->height, 1);
944
945 if ((res = mmap_init(ctx)) ||
946 (res = mmap_start(ctx)) < 0)
947 goto fail;
948
949 s->top_field_first = first_field(s);
950
951 st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
952 st->codecpar->codec_id = codec_id;
953 if (codec_id == AV_CODEC_ID_RAWVIDEO)
954 st->codecpar->codec_tag =
955 avcodec_pix_fmt_to_codec_tag(st->codecpar->format);
956 else if (codec_id == AV_CODEC_ID_H264) {
957 st->need_parsing = AVSTREAM_PARSE_FULL_ONCE;
958 }
959 if (desired_format == V4L2_PIX_FMT_YVU420)
960 st->codecpar->codec_tag = MKTAG('Y', 'V', '1', '2');
961 else if (desired_format == V4L2_PIX_FMT_YVU410)
962 st->codecpar->codec_tag = MKTAG('Y', 'V', 'U', '9');
963 st->codecpar->width = s->width;
964 st->codecpar->height = s->height;
965 if (st->avg_frame_rate.den)
966 st->codecpar->bit_rate = s->frame_size * av_q2d(st->avg_frame_rate) * 8;
967
968 return 0;
969
970fail:
971 v4l2_close(s->fd);
972 return res;
973}
974
975static int v4l2_read_packet(AVFormatContext *ctx, AVPacket *pkt)
976{
977#if FF_API_CODED_FRAME && FF_API_LAVF_AVCTX
978FF_DISABLE_DEPRECATION_WARNINGS
979 struct video_data *s = ctx->priv_data;
980 AVFrame *frame = ctx->streams[0]->codec->coded_frame;
981FF_ENABLE_DEPRECATION_WARNINGS
982#endif
983 int res;
984
985 if ((res = mmap_read_frame(ctx, pkt)) < 0) {
986 return res;
987 }
988
989#if FF_API_CODED_FRAME && FF_API_LAVF_AVCTX
990FF_DISABLE_DEPRECATION_WARNINGS
991 if (frame && s->interlaced) {
992 frame->interlaced_frame = 1;
993 frame->top_field_first = s->top_field_first;
994 }
995FF_ENABLE_DEPRECATION_WARNINGS
996#endif
997
998 return pkt->size;
999}
1000
1001static int v4l2_read_close(AVFormatContext *ctx)
1002{
1003 struct video_data *s = ctx->priv_data;
1004
1005 if (atomic_load(&s->buffers_queued) != s->buffers)
1006 av_log(ctx, AV_LOG_WARNING, "Some buffers are still owned by the caller on "
1007 "close.\n");
1008
1009 mmap_close(s);
1010
1011 v4l2_close(s->fd);
1012 return 0;
1013}
1014
1015static int v4l2_is_v4l_dev(const char *name)
1016{
1017 return !strncmp(name, "video", 5) ||
1018 !strncmp(name, "radio", 5) ||
1019 !strncmp(name, "vbi", 3) ||
1020 !strncmp(name, "v4l-subdev", 10);
1021}
1022
1023static int v4l2_get_device_list(AVFormatContext *ctx, AVDeviceInfoList *device_list)
1024{
1025 struct video_data *s = ctx->priv_data;
1026 DIR *dir;
1027 struct dirent *entry;
1028 AVDeviceInfo *device = NULL;
1029 struct v4l2_capability cap;
1030 int ret = 0;
1031
1032 if (!device_list)
1033 return AVERROR(EINVAL);
1034
1035 dir = opendir("/dev");
1036 if (!dir) {
1037 ret = AVERROR(errno);
1038 av_log(ctx, AV_LOG_ERROR, "Couldn't open the directory: %s\n", av_err2str(ret));
1039 return ret;
1040 }
1041 while ((entry = readdir(dir))) {
1042 if (!v4l2_is_v4l_dev(entry->d_name))
1043 continue;
1044
1045 snprintf(ctx->filename, sizeof(ctx->filename), "/dev/%s", entry->d_name);
1046 if ((s->fd = device_open(ctx)) < 0)
1047 continue;
1048
1049 if (v4l2_ioctl(s->fd, VIDIOC_QUERYCAP, &cap) < 0) {
1050 ret = AVERROR(errno);
1051 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n", av_err2str(ret));
1052 goto fail;
1053 }
1054
1055 device = av_mallocz(sizeof(AVDeviceInfo));
1056 if (!device) {
1057 ret = AVERROR(ENOMEM);
1058 goto fail;
1059 }
1060 device->device_name = av_strdup(ctx->filename);
1061 device->device_description = av_strdup(cap.card);
1062 if (!device->device_name || !device->device_description) {
1063 ret = AVERROR(ENOMEM);
1064 goto fail;
1065 }
1066
1067 if ((ret = av_dynarray_add_nofree(&device_list->devices,
1068 &device_list->nb_devices, device)) < 0)
1069 goto fail;
1070
1071 v4l2_close(s->fd);
1072 s->fd = -1;
1073 continue;
1074
1075 fail:
1076 if (device) {
1077 av_freep(&device->device_name);
1078 av_freep(&device->device_description);
1079 av_freep(&device);
1080 }
1081 if (s->fd >= 0)
1082 v4l2_close(s->fd);
1083 s->fd = -1;
1084 break;
1085 }
1086 closedir(dir);
1087 return ret;
1088}
1089
1090#define OFFSET(x) offsetof(struct video_data, x)
1091#define DEC AV_OPT_FLAG_DECODING_PARAM
1092
1093static const AVOption options[] = {
1094 { "standard", "set TV standard, used only by analog frame grabber", OFFSET(standard), AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, DEC },
1095 { "channel", "set TV channel, used only by frame grabber", OFFSET(channel), AV_OPT_TYPE_INT, {.i64 = -1 }, -1, INT_MAX, DEC },
1096 { "video_size", "set frame size", OFFSET(width), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, DEC },
1097 { "pixel_format", "set preferred pixel format", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
1098 { "input_format", "set preferred pixel format (for raw video) or codec name", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
1099 { "framerate", "set frame rate", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
1100
1101 { "list_formats", "list available formats and exit", OFFSET(list_format), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, DEC, "list_formats" },
1102 { "all", "show all available formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_ALLFORMATS }, 0, INT_MAX, DEC, "list_formats" },
1103 { "raw", "show only non-compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_RAWFORMATS }, 0, INT_MAX, DEC, "list_formats" },
1104 { "compressed", "show only compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_COMPFORMATS }, 0, INT_MAX, DEC, "list_formats" },
1105
1106 { "list_standards", "list supported standards and exit", OFFSET(list_standard), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 1, DEC, "list_standards" },
1107 { "all", "show all supported standards", OFFSET(list_standard), AV_OPT_TYPE_CONST, {.i64 = 1 }, 0, 0, DEC, "list_standards" },
1108
1109 { "timestamps", "set type of timestamps for grabbed frames", OFFSET(ts_mode), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 2, DEC, "timestamps" },
1110 { "ts", "set type of timestamps for grabbed frames", OFFSET(ts_mode), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 2, DEC, "timestamps" },
1111 { "default", "use timestamps from the kernel", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.i64 = V4L_TS_DEFAULT }, 0, 2, DEC, "timestamps" },
1112 { "abs", "use absolute timestamps (wall clock)", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.i64 = V4L_TS_ABS }, 0, 2, DEC, "timestamps" },
1113 { "mono2abs", "force conversion from monotonic to absolute timestamps", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.i64 = V4L_TS_MONO2ABS }, 0, 2, DEC, "timestamps" },
1114 { "use_libv4l2", "use libv4l2 (v4l-utils) conversion functions", OFFSET(use_libv4l2), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, DEC },
1115 { NULL },
1116};
1117
1118static const AVClass v4l2_class = {
1119 .class_name = "V4L2 indev",
1120 .item_name = av_default_item_name,
1121 .option = options,
1122 .version = LIBAVUTIL_VERSION_INT,
1123 .category = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
1124};
1125
1126AVInputFormat ff_v4l2_demuxer = {
1127 .name = "video4linux2,v4l2",
1128 .long_name = NULL_IF_CONFIG_SMALL("Video4Linux2 device grab"),
1129 .priv_data_size = sizeof(struct video_data),
1130 .read_probe = v4l2_read_probe,
1131 .read_header = v4l2_read_header,
1132 .read_packet = v4l2_read_packet,
1133 .read_close = v4l2_read_close,
1134 .get_device_list = v4l2_get_device_list,
1135 .flags = AVFMT_NOFILE,
1136 .priv_class = &v4l2_class,
1137};
1138
generated by cgit at 2024-05-17 08:25:17 (GMT)