2 * Copyright (c) 2000,2001 Fabrice Bellard
3 * Copyright (c) 2006 Luca Abeni
5 * This file is part of FFmpeg.
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.
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.
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
24 * Video4Linux2 grab interface
26 * Part of this file is based on the V4L2 video capture example
27 * (http://linuxtv.org/downloads/v4l-dvb-apis/capture-example.html)
29 * Thanks to Michael Niedermayer for providing the mapping between
30 * V4L2_PIX_FMT_* and AV_PIX_FMT_*
33 #include <stdatomic.h>
35 #include "v4l2-common.h"
42 static const int desired_video_buffers = 256;
44 #define V4L_ALLFORMATS 3
45 #define V4L_RAWFORMATS 1
46 #define V4L_COMPFORMATS 2
49 * Return timestamps to the user exactly as returned by the kernel
51 #define V4L_TS_DEFAULT 0
53 * Autodetect the kind of timestamps returned by the kernel and convert to
54 * absolute (wall clock) timestamps.
58 * Assume kernel timestamps are from the monotonic clock and convert to
59 * absolute timestamps.
61 #define V4L_TS_MONO2ABS 2
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
68 #define V4L_TS_CONVERT_READY V4L_TS_DEFAULT
73 int pixelformat; /* V4L2_PIX_FMT_* */
79 TimeFilter *timefilter;
83 atomic_int buffers_queued;
85 unsigned int *buf_len;
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. */
95 int (*open_f)(const char *file, int oflag, ...);
96 int (*close_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);
105 struct video_data *s;
109 static int device_open(AVFormatContext *ctx, const char* device_path)
111 struct video_data *s = ctx->priv_data;
112 struct v4l2_capability cap;
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; \
127 if (s->use_libv4l2) {
131 av_log(ctx, AV_LOG_ERROR, "libavdevice is not built with libv4l2 support.\n");
132 return AVERROR(EINVAL);
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
146 if (ctx->flags & AVFMT_FLAG_NONBLOCK) {
150 fd = v4l2_open(device_path, flags, 0);
152 err = AVERROR(errno);
153 av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s: %s\n",
154 device_path, av_err2str(err));
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",
165 av_log(ctx, AV_LOG_VERBOSE, "fd:%d capabilities:%x\n",
166 fd, cap.capabilities);
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);
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);
188 static int device_init(AVFormatContext *ctx, int *width, int *height,
189 uint32_t pixelformat)
191 struct video_data *s = ctx->priv_data;
192 struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
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;
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);
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;
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);
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");
230 static int first_field(const struct video_data *s)
235 res = v4l2_ioctl(s->fd, VIDIOC_G_STD, &std);
238 if (std & V4L2_STD_NTSC)
244 #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
245 static void list_framesizes(AVFormatContext *ctx, uint32_t pixelformat)
247 const struct video_data *s = ctx->priv_data;
248 struct v4l2_frmsizeenum vfse = { .pixel_format = pixelformat };
250 while(!v4l2_ioctl(s->fd, VIDIOC_ENUM_FRAMESIZES, &vfse)) {
252 case V4L2_FRMSIZE_TYPE_DISCRETE:
253 av_log(ctx, AV_LOG_INFO, " %ux%u",
254 vfse.discrete.width, vfse.discrete.height);
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);
271 static void list_formats(AVFormatContext *ctx, int type)
273 const struct video_data *s = ctx->priv_data;
274 struct v4l2_fmtdesc vfd = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
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);
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",
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",
298 #ifdef V4L2_FMT_FLAG_EMULATED
299 if (vfd.flags & V4L2_FMT_FLAG_EMULATED)
300 av_log(ctx, AV_LOG_INFO, " Emulated :");
302 #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
303 list_framesizes(ctx, vfd.pixelformat);
305 av_log(ctx, AV_LOG_INFO, "\n");
309 static void list_standards(AVFormatContext *ctx)
312 struct video_data *s = ctx->priv_data;
313 struct v4l2_standard standard;
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)) {
324 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMSTD): %s\n", av_err2str(ret));
328 av_log(ctx, AV_LOG_INFO, "%2d, %16"PRIx64", %s\n",
329 standard.index, (uint64_t)standard.id, standard.name);
333 static int mmap_init(AVFormatContext *ctx)
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
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));
350 av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");
351 return AVERROR(ENOMEM);
353 s->buffers = req.count;
354 s->buf_start = av_malloc_array(s->buffers, sizeof(void *));
356 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
357 return AVERROR(ENOMEM);
359 s->buf_len = av_malloc_array(s->buffers, sizeof(unsigned int));
361 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
362 av_freep(&s->buf_start);
363 return AVERROR(ENOMEM);
366 for (i = 0; i < req.count; i++) {
367 struct v4l2_buffer buf = {
368 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
370 .memory = V4L2_MEMORY_MMAP
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));
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);
385 s->buf_start[i] = v4l2_mmap(NULL, buf.length,
386 PROT_READ | PROT_WRITE, MAP_SHARED,
387 s->fd, buf.m.offset);
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));
399 static int enqueue_buffer(struct video_data *s, struct v4l2_buffer *buf)
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));
407 atomic_fetch_add(&s->buffers_queued, 1);
413 static void mmap_release_buffer(void *opaque, uint8_t *data)
415 struct v4l2_buffer buf = { 0 };
416 struct buff_data *buf_descriptor = opaque;
417 struct video_data *s = buf_descriptor->s;
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);
424 enqueue_buffer(s, &buf);
427 #if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
428 static int64_t av_gettime_monotonic(void)
430 return av_gettime_relative();
434 static int init_convert_timestamp(AVFormatContext *ctx, int64_t ts)
436 struct video_data *s = ctx->priv_data;
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;
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);
457 return AVERROR(ENOMEM);
458 s->ts_mode = V4L_TS_CONVERT_READY;
463 av_log(ctx, AV_LOG_ERROR, "Unknown timestamps\n");
467 static int convert_timestamp(AVFormatContext *ctx, int64_t *ts)
469 struct video_data *s = ctx->priv_data;
472 int r = init_convert_timestamp(ctx, *ts);
476 #if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
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);
488 static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
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
495 struct timeval buf_ts;
500 /* FIXME: Some special treatment might be needed in case of loss of signal... */
501 while ((res = v4l2_ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 && (errno == EINTR));
504 return AVERROR(EAGAIN);
506 res = AVERROR(errno);
507 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n",
512 buf_ts = buf.timestamp;
514 if (buf.index >= s->buffers) {
515 av_log(ctx, AV_LOG_ERROR, "Invalid buffer index received.\n");
516 return AVERROR(EINVAL);
518 atomic_fetch_add(&s->buffers_queued, -1);
519 // always keep at least one buffer queued
520 av_assert0(atomic_load(&s->buffers_queued) >= 1);
522 #ifdef V4L2_BUF_FLAG_ERROR
523 if (buf.flags & V4L2_BUF_FLAG_ERROR) {
524 av_log(ctx, AV_LOG_WARNING,
525 "Dequeued v4l2 buffer contains corrupted data (%d bytes).\n",
531 /* CPIA is a compressed format and we don't know the exact number of bytes
532 * used by a frame, so set it here as the driver announces it. */
533 if (ctx->video_codec_id == AV_CODEC_ID_CPIA)
534 s->frame_size = buf.bytesused;
536 if (s->frame_size > 0 && buf.bytesused != s->frame_size) {
537 av_log(ctx, AV_LOG_ERROR,
538 "Dequeued v4l2 buffer contains %d bytes, but %d were expected. Flags: 0x%08X.\n",
539 buf.bytesused, s->frame_size, buf.flags);
540 enqueue_buffer(s, &buf);
541 return AVERROR_INVALIDDATA;
545 /* Image is at s->buff_start[buf.index] */
546 if (atomic_load(&s->buffers_queued) == FFMAX(s->buffers / 8, 1)) {
547 /* when we start getting low on queued buffers, fall back on copying data */
548 res = av_new_packet(pkt, buf.bytesused);
550 av_log(ctx, AV_LOG_ERROR, "Error allocating a packet.\n");
551 enqueue_buffer(s, &buf);
554 memcpy(pkt->data, s->buf_start[buf.index], buf.bytesused);
556 res = enqueue_buffer(s, &buf);
558 av_packet_unref(pkt);
562 struct buff_data *buf_descriptor;
564 pkt->data = s->buf_start[buf.index];
565 pkt->size = buf.bytesused;
567 buf_descriptor = av_malloc(sizeof(struct buff_data));
568 if (!buf_descriptor) {
569 /* Something went wrong... Since av_malloc() failed, we cannot even
570 * allocate a buffer for memcpying into it
572 av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
573 enqueue_buffer(s, &buf);
575 return AVERROR(ENOMEM);
577 buf_descriptor->index = buf.index;
578 buf_descriptor->s = s;
580 pkt->buf = av_buffer_create(pkt->data, pkt->size, mmap_release_buffer,
583 av_log(ctx, AV_LOG_ERROR, "Failed to create a buffer\n");
584 enqueue_buffer(s, &buf);
585 av_freep(&buf_descriptor);
586 return AVERROR(ENOMEM);
589 pkt->pts = buf_ts.tv_sec * INT64_C(1000000) + buf_ts.tv_usec;
590 convert_timestamp(ctx, &pkt->pts);
595 static int mmap_start(AVFormatContext *ctx)
597 struct video_data *s = ctx->priv_data;
598 enum v4l2_buf_type type;
601 for (i = 0; i < s->buffers; i++) {
602 struct v4l2_buffer buf = {
603 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
605 .memory = V4L2_MEMORY_MMAP
608 if (v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf) < 0) {
609 res = AVERROR(errno);
610 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n",
615 atomic_store(&s->buffers_queued, s->buffers);
617 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
618 if (v4l2_ioctl(s->fd, VIDIOC_STREAMON, &type) < 0) {
619 res = AVERROR(errno);
620 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n",
628 static void mmap_close(struct video_data *s)
630 enum v4l2_buf_type type;
633 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
634 /* We do not check for the result, because we could
635 * not do anything about it anyway...
637 v4l2_ioctl(s->fd, VIDIOC_STREAMOFF, &type);
638 for (i = 0; i < s->buffers; i++) {
639 v4l2_munmap(s->buf_start[i], s->buf_len[i]);
641 av_freep(&s->buf_start);
642 av_freep(&s->buf_len);
645 static int v4l2_set_parameters(AVFormatContext *ctx)
647 struct video_data *s = ctx->priv_data;
648 struct v4l2_standard standard = { 0 };
649 struct v4l2_streamparm streamparm = { 0 };
650 struct v4l2_fract *tpf;
651 AVRational framerate_q = { 0 };
655 (ret = av_parse_video_rate(&framerate_q, s->framerate)) < 0) {
656 av_log(ctx, AV_LOG_ERROR, "Could not parse framerate '%s'.\n",
664 av_log(ctx, AV_LOG_DEBUG, "Setting standard: %s\n", s->standard);
665 /* set tv standard */
668 if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
669 ret = AVERROR(errno);
672 if (!av_strcasecmp(standard.name, s->standard))
676 av_log(ctx, AV_LOG_ERROR, "Unknown or unsupported standard '%s'\n", s->standard);
680 if (v4l2_ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
681 ret = AVERROR(errno);
682 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_S_STD): %s\n", av_err2str(ret));
686 av_log(ctx, AV_LOG_WARNING,
687 "This device does not support any standard\n");
692 if (v4l2_ioctl(s->fd, VIDIOC_G_STD, &s->std_id) == 0) {
693 tpf = &standard.frameperiod;
696 if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
697 ret = AVERROR(errno);
698 if (ret == AVERROR(EINVAL)
700 || ret == AVERROR(ENODATA)
703 tpf = &streamparm.parm.capture.timeperframe;
706 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMSTD): %s\n", av_err2str(ret));
709 if (standard.id == s->std_id) {
710 av_log(ctx, AV_LOG_DEBUG,
711 "Current standard: %s, id: %"PRIx64", frameperiod: %d/%d\n",
712 standard.name, (uint64_t)standard.id, tpf->numerator, tpf->denominator);
717 tpf = &streamparm.parm.capture.timeperframe;
720 streamparm.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
721 if (v4l2_ioctl(s->fd, VIDIOC_G_PARM, &streamparm) < 0) {
722 ret = AVERROR(errno);
723 av_log(ctx, AV_LOG_WARNING, "ioctl(VIDIOC_G_PARM): %s\n", av_err2str(ret));
724 } else if (framerate_q.num && framerate_q.den) {
725 if (streamparm.parm.capture.capability & V4L2_CAP_TIMEPERFRAME) {
726 tpf = &streamparm.parm.capture.timeperframe;
728 av_log(ctx, AV_LOG_DEBUG, "Setting time per frame to %d/%d\n",
729 framerate_q.den, framerate_q.num);
730 tpf->numerator = framerate_q.den;
731 tpf->denominator = framerate_q.num;
733 if (v4l2_ioctl(s->fd, VIDIOC_S_PARM, &streamparm) < 0) {
734 ret = AVERROR(errno);
735 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_S_PARM): %s\n",
740 if (framerate_q.num != tpf->denominator ||
741 framerate_q.den != tpf->numerator) {
742 av_log(ctx, AV_LOG_INFO,
743 "The driver changed the time per frame from "
745 framerate_q.den, framerate_q.num,
746 tpf->numerator, tpf->denominator);
749 av_log(ctx, AV_LOG_WARNING,
750 "The driver does not permit changing the time per frame\n");
753 if (tpf->denominator > 0 && tpf->numerator > 0) {
754 ctx->streams[0]->avg_frame_rate.num = tpf->denominator;
755 ctx->streams[0]->avg_frame_rate.den = tpf->numerator;
756 ctx->streams[0]->r_frame_rate = ctx->streams[0]->avg_frame_rate;
758 av_log(ctx, AV_LOG_WARNING, "Time per frame unknown\n");
763 static int device_try_init(AVFormatContext *ctx,
764 enum AVPixelFormat pix_fmt,
767 uint32_t *desired_format,
768 enum AVCodecID *codec_id)
772 *desired_format = ff_fmt_ff2v4l(pix_fmt, ctx->video_codec_id);
774 if (*desired_format) {
775 ret = device_init(ctx, width, height, *desired_format);
778 if (ret != AVERROR(EINVAL))
783 if (!*desired_format) {
784 for (i = 0; ff_fmt_conversion_table[i].codec_id != AV_CODEC_ID_NONE; i++) {
785 if (ctx->video_codec_id == AV_CODEC_ID_NONE ||
786 ff_fmt_conversion_table[i].codec_id == ctx->video_codec_id) {
787 av_log(ctx, AV_LOG_DEBUG, "Trying to set codec:%s pix_fmt:%s\n",
788 avcodec_get_name(ff_fmt_conversion_table[i].codec_id),
789 (char *)av_x_if_null(av_get_pix_fmt_name(ff_fmt_conversion_table[i].ff_fmt), "none"));
791 *desired_format = ff_fmt_conversion_table[i].v4l2_fmt;
792 ret = device_init(ctx, width, height, *desired_format);
795 else if (ret != AVERROR(EINVAL))
801 if (*desired_format == 0) {
802 av_log(ctx, AV_LOG_ERROR, "Cannot find a proper format for "
803 "codec '%s' (id %d), pixel format '%s' (id %d)\n",
804 avcodec_get_name(ctx->video_codec_id), ctx->video_codec_id,
805 (char *)av_x_if_null(av_get_pix_fmt_name(pix_fmt), "none"), pix_fmt);
806 ret = AVERROR(EINVAL);
810 *codec_id = ff_fmt_v4l2codec(*desired_format);
811 av_assert0(*codec_id != AV_CODEC_ID_NONE);
815 static int v4l2_read_probe(AVProbeData *p)
817 if (av_strstart(p->filename, "/dev/video", NULL))
818 return AVPROBE_SCORE_MAX - 1;
822 static int v4l2_read_header(AVFormatContext *ctx)
824 struct video_data *s = ctx->priv_data;
827 uint32_t desired_format;
828 enum AVCodecID codec_id = AV_CODEC_ID_NONE;
829 enum AVPixelFormat pix_fmt = AV_PIX_FMT_NONE;
830 struct v4l2_input input = { 0 };
832 st = avformat_new_stream(ctx, NULL);
834 return AVERROR(ENOMEM);
837 /* silence libv4l2 logging. if fopen() fails v4l2_log_file will be NULL
838 and errors will get sent to stderr */
840 v4l2_log_file = fopen("/dev/null", "w");
843 s->fd = device_open(ctx, ctx->url);
847 if (s->channel != -1) {
848 /* set video input */
849 av_log(ctx, AV_LOG_DEBUG, "Selecting input_channel: %d\n", s->channel);
850 if (v4l2_ioctl(s->fd, VIDIOC_S_INPUT, &s->channel) < 0) {
851 res = AVERROR(errno);
852 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_S_INPUT): %s\n", av_err2str(res));
856 /* get current video input */
857 if (v4l2_ioctl(s->fd, VIDIOC_G_INPUT, &s->channel) < 0) {
858 res = AVERROR(errno);
859 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_G_INPUT): %s\n", av_err2str(res));
865 input.index = s->channel;
866 if (v4l2_ioctl(s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
867 res = AVERROR(errno);
868 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMINPUT): %s\n", av_err2str(res));
871 s->std_id = input.std;
872 av_log(ctx, AV_LOG_DEBUG, "Current input_channel: %d, input_name: %s, input_std: %"PRIx64"\n",
873 s->channel, input.name, (uint64_t)input.std);
875 if (s->list_format) {
876 list_formats(ctx, s->list_format);
881 if (s->list_standard) {
887 avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
889 if (s->pixel_format) {
890 const AVCodecDescriptor *desc = avcodec_descriptor_get_by_name(s->pixel_format);
893 ctx->video_codec_id = desc->id;
895 pix_fmt = av_get_pix_fmt(s->pixel_format);
897 if (pix_fmt == AV_PIX_FMT_NONE && !desc) {
898 av_log(ctx, AV_LOG_ERROR, "No such input format: %s.\n",
901 res = AVERROR(EINVAL);
906 if (!s->width && !s->height) {
907 struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
909 av_log(ctx, AV_LOG_VERBOSE,
910 "Querying the device for the current frame size\n");
911 if (v4l2_ioctl(s->fd, VIDIOC_G_FMT, &fmt) < 0) {
912 res = AVERROR(errno);
913 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n",
918 s->width = fmt.fmt.pix.width;
919 s->height = fmt.fmt.pix.height;
920 av_log(ctx, AV_LOG_VERBOSE,
921 "Setting frame size to %dx%d\n", s->width, s->height);
924 res = device_try_init(ctx, pix_fmt, &s->width, &s->height, &desired_format, &codec_id);
928 /* If no pixel_format was specified, the codec_id was not known up
929 * until now. Set video_codec_id in the context, as codec_id will
930 * not be available outside this function
932 if (codec_id != AV_CODEC_ID_NONE && ctx->video_codec_id == AV_CODEC_ID_NONE)
933 ctx->video_codec_id = codec_id;
935 if ((res = av_image_check_size(s->width, s->height, 0, ctx)) < 0)
938 s->pixelformat = desired_format;
940 if ((res = v4l2_set_parameters(ctx)) < 0)
943 st->codecpar->format = ff_fmt_v4l2ff(desired_format, codec_id);
944 if (st->codecpar->format != AV_PIX_FMT_NONE)
945 s->frame_size = av_image_get_buffer_size(st->codecpar->format,
946 s->width, s->height, 1);
948 if ((res = mmap_init(ctx)) ||
949 (res = mmap_start(ctx)) < 0)
952 s->top_field_first = first_field(s);
954 st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
955 st->codecpar->codec_id = codec_id;
956 if (codec_id == AV_CODEC_ID_RAWVIDEO)
957 st->codecpar->codec_tag =
958 avcodec_pix_fmt_to_codec_tag(st->codecpar->format);
959 else if (codec_id == AV_CODEC_ID_H264) {
960 st->need_parsing = AVSTREAM_PARSE_FULL_ONCE;
962 if (desired_format == V4L2_PIX_FMT_YVU420)
963 st->codecpar->codec_tag = MKTAG('Y', 'V', '1', '2');
964 else if (desired_format == V4L2_PIX_FMT_YVU410)
965 st->codecpar->codec_tag = MKTAG('Y', 'V', 'U', '9');
966 st->codecpar->width = s->width;
967 st->codecpar->height = s->height;
968 if (st->avg_frame_rate.den)
969 st->codecpar->bit_rate = s->frame_size * av_q2d(st->avg_frame_rate) * 8;
978 static int v4l2_read_packet(AVFormatContext *ctx, AVPacket *pkt)
980 #if FF_API_CODED_FRAME && FF_API_LAVF_AVCTX
981 FF_DISABLE_DEPRECATION_WARNINGS
982 struct video_data *s = ctx->priv_data;
983 AVFrame *frame = ctx->streams[0]->codec->coded_frame;
984 FF_ENABLE_DEPRECATION_WARNINGS
988 if ((res = mmap_read_frame(ctx, pkt)) < 0) {
992 #if FF_API_CODED_FRAME && FF_API_LAVF_AVCTX
993 FF_DISABLE_DEPRECATION_WARNINGS
994 if (frame && s->interlaced) {
995 frame->interlaced_frame = 1;
996 frame->top_field_first = s->top_field_first;
998 FF_ENABLE_DEPRECATION_WARNINGS
1004 static int v4l2_read_close(AVFormatContext *ctx)
1006 struct video_data *s = ctx->priv_data;
1008 if (atomic_load(&s->buffers_queued) != s->buffers)
1009 av_log(ctx, AV_LOG_WARNING, "Some buffers are still owned by the caller on "
1018 static int v4l2_is_v4l_dev(const char *name)
1020 return !strncmp(name, "video", 5) ||
1021 !strncmp(name, "radio", 5) ||
1022 !strncmp(name, "vbi", 3) ||
1023 !strncmp(name, "v4l-subdev", 10);
1026 static int v4l2_get_device_list(AVFormatContext *ctx, AVDeviceInfoList *device_list)
1028 struct video_data *s = ctx->priv_data;
1030 struct dirent *entry;
1031 AVDeviceInfo *device = NULL;
1032 struct v4l2_capability cap;
1036 return AVERROR(EINVAL);
1038 dir = opendir("/dev");
1040 ret = AVERROR(errno);
1041 av_log(ctx, AV_LOG_ERROR, "Couldn't open the directory: %s\n", av_err2str(ret));
1044 while ((entry = readdir(dir))) {
1045 char device_name[256];
1047 if (!v4l2_is_v4l_dev(entry->d_name))
1050 snprintf(device_name, sizeof(device_name), "/dev/%s", entry->d_name);
1051 if ((s->fd = device_open(ctx, device_name)) < 0)
1054 if (v4l2_ioctl(s->fd, VIDIOC_QUERYCAP, &cap) < 0) {
1055 ret = AVERROR(errno);
1056 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n", av_err2str(ret));
1060 device = av_mallocz(sizeof(AVDeviceInfo));
1062 ret = AVERROR(ENOMEM);
1065 device->device_name = av_strdup(device_name);
1066 device->device_description = av_strdup(cap.card);
1067 if (!device->device_name || !device->device_description) {
1068 ret = AVERROR(ENOMEM);
1072 if ((ret = av_dynarray_add_nofree(&device_list->devices,
1073 &device_list->nb_devices, device)) < 0)
1082 av_freep(&device->device_name);
1083 av_freep(&device->device_description);
1095 #define OFFSET(x) offsetof(struct video_data, x)
1096 #define DEC AV_OPT_FLAG_DECODING_PARAM
1098 static const AVOption options[] = {
1099 { "standard", "set TV standard, used only by analog frame grabber", OFFSET(standard), AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, DEC },
1100 { "channel", "set TV channel, used only by frame grabber", OFFSET(channel), AV_OPT_TYPE_INT, {.i64 = -1 }, -1, INT_MAX, DEC },
1101 { "video_size", "set frame size", OFFSET(width), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, DEC },
1102 { "pixel_format", "set preferred pixel format", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
1103 { "input_format", "set preferred pixel format (for raw video) or codec name", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
1104 { "framerate", "set frame rate", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
1106 { "list_formats", "list available formats and exit", OFFSET(list_format), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, DEC, "list_formats" },
1107 { "all", "show all available formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_ALLFORMATS }, 0, INT_MAX, DEC, "list_formats" },
1108 { "raw", "show only non-compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_RAWFORMATS }, 0, INT_MAX, DEC, "list_formats" },
1109 { "compressed", "show only compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_COMPFORMATS }, 0, INT_MAX, DEC, "list_formats" },
1111 { "list_standards", "list supported standards and exit", OFFSET(list_standard), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 1, DEC, "list_standards" },
1112 { "all", "show all supported standards", OFFSET(list_standard), AV_OPT_TYPE_CONST, {.i64 = 1 }, 0, 0, DEC, "list_standards" },
1114 { "timestamps", "set type of timestamps for grabbed frames", OFFSET(ts_mode), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 2, DEC, "timestamps" },
1115 { "ts", "set type of timestamps for grabbed frames", OFFSET(ts_mode), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 2, DEC, "timestamps" },
1116 { "default", "use timestamps from the kernel", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.i64 = V4L_TS_DEFAULT }, 0, 2, DEC, "timestamps" },
1117 { "abs", "use absolute timestamps (wall clock)", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.i64 = V4L_TS_ABS }, 0, 2, DEC, "timestamps" },
1118 { "mono2abs", "force conversion from monotonic to absolute timestamps", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.i64 = V4L_TS_MONO2ABS }, 0, 2, DEC, "timestamps" },
1119 { "use_libv4l2", "use libv4l2 (v4l-utils) conversion functions", OFFSET(use_libv4l2), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, DEC },
1123 static const AVClass v4l2_class = {
1124 .class_name = "V4L2 indev",
1125 .item_name = av_default_item_name,
1127 .version = LIBAVUTIL_VERSION_INT,
1128 .category = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
1131 AVInputFormat ff_v4l2_demuxer = {
1132 .name = "video4linux2,v4l2",
1133 .long_name = NULL_IF_CONFIG_SMALL("Video4Linux2 device grab"),
1134 .priv_data_size = sizeof(struct video_data),
1135 .read_probe = v4l2_read_probe,
1136 .read_header = v4l2_read_header,
1137 .read_packet = v4l2_read_packet,
1138 .read_close = v4l2_read_close,
1139 .get_device_list = v4l2_get_device_list,
1140 .flags = AVFMT_NOFILE,
1141 .priv_class = &v4l2_class,