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);
99 int (*ioctl_f)(int fd, unsigned long int request, ...);
101 int (*ioctl_f)(int fd, int request, ...);
103 ssize_t (*read_f)(int fd, void *buffer, size_t n);
104 void *(*mmap_f)(void *start, size_t length, int prot, int flags, int fd, int64_t offset);
105 int (*munmap_f)(void *_start, size_t length);
109 struct video_data *s;
113 static int device_open(AVFormatContext *ctx, const char* device_path)
115 struct video_data *s = ctx->priv_data;
116 struct v4l2_capability cap;
121 #define SET_WRAPPERS(prefix) do { \
122 s->open_f = prefix ## open; \
123 s->close_f = prefix ## close; \
124 s->dup_f = prefix ## dup; \
125 s->ioctl_f = prefix ## ioctl; \
126 s->read_f = prefix ## read; \
127 s->mmap_f = prefix ## mmap; \
128 s->munmap_f = prefix ## munmap; \
131 if (s->use_libv4l2) {
135 av_log(ctx, AV_LOG_ERROR, "libavdevice is not built with libv4l2 support.\n");
136 return AVERROR(EINVAL);
142 #define v4l2_open s->open_f
143 #define v4l2_close s->close_f
144 #define v4l2_dup s->dup_f
145 #define v4l2_ioctl s->ioctl_f
146 #define v4l2_read s->read_f
147 #define v4l2_mmap s->mmap_f
148 #define v4l2_munmap s->munmap_f
150 if (ctx->flags & AVFMT_FLAG_NONBLOCK) {
154 fd = v4l2_open(device_path, flags, 0);
156 err = AVERROR(errno);
157 av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s: %s\n",
158 device_path, av_err2str(err));
162 if (v4l2_ioctl(fd, VIDIOC_QUERYCAP, &cap) < 0) {
163 err = AVERROR(errno);
164 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
169 av_log(ctx, AV_LOG_VERBOSE, "fd:%d capabilities:%x\n",
170 fd, cap.capabilities);
172 if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {
173 av_log(ctx, AV_LOG_ERROR, "Not a video capture device.\n");
174 err = AVERROR(ENODEV);
178 if (!(cap.capabilities & V4L2_CAP_STREAMING)) {
179 av_log(ctx, AV_LOG_ERROR,
180 "The device does not support the streaming I/O method.\n");
181 err = AVERROR(ENOSYS);
192 static int device_init(AVFormatContext *ctx, int *width, int *height,
193 uint32_t pixelformat)
195 struct video_data *s = ctx->priv_data;
196 struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
199 fmt.fmt.pix.width = *width;
200 fmt.fmt.pix.height = *height;
201 fmt.fmt.pix.pixelformat = pixelformat;
202 fmt.fmt.pix.field = V4L2_FIELD_ANY;
204 /* Some drivers will fail and return EINVAL when the pixelformat
205 is not supported (even if type field is valid and supported) */
206 if (v4l2_ioctl(s->fd, VIDIOC_S_FMT, &fmt) < 0)
207 res = AVERROR(errno);
209 if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {
210 av_log(ctx, AV_LOG_INFO,
211 "The V4L2 driver changed the video from %dx%d to %dx%d\n",
212 *width, *height, fmt.fmt.pix.width, fmt.fmt.pix.height);
213 *width = fmt.fmt.pix.width;
214 *height = fmt.fmt.pix.height;
217 if (pixelformat != fmt.fmt.pix.pixelformat) {
218 av_log(ctx, AV_LOG_DEBUG,
219 "The V4L2 driver changed the pixel format "
220 "from 0x%08X to 0x%08X\n",
221 pixelformat, fmt.fmt.pix.pixelformat);
222 res = AVERROR(EINVAL);
225 if (fmt.fmt.pix.field == V4L2_FIELD_INTERLACED) {
226 av_log(ctx, AV_LOG_DEBUG,
227 "The V4L2 driver is using the interlaced mode\n");
234 static int first_field(const struct video_data *s)
239 res = v4l2_ioctl(s->fd, VIDIOC_G_STD, &std);
242 if (std & V4L2_STD_NTSC)
248 #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
249 static void list_framesizes(AVFormatContext *ctx, uint32_t pixelformat)
251 const struct video_data *s = ctx->priv_data;
252 struct v4l2_frmsizeenum vfse = { .pixel_format = pixelformat };
254 while(!v4l2_ioctl(s->fd, VIDIOC_ENUM_FRAMESIZES, &vfse)) {
256 case V4L2_FRMSIZE_TYPE_DISCRETE:
257 av_log(ctx, AV_LOG_INFO, " %ux%u",
258 vfse.discrete.width, vfse.discrete.height);
260 case V4L2_FRMSIZE_TYPE_CONTINUOUS:
261 case V4L2_FRMSIZE_TYPE_STEPWISE:
262 av_log(ctx, AV_LOG_INFO, " {%u-%u, %u}x{%u-%u, %u}",
263 vfse.stepwise.min_width,
264 vfse.stepwise.max_width,
265 vfse.stepwise.step_width,
266 vfse.stepwise.min_height,
267 vfse.stepwise.max_height,
268 vfse.stepwise.step_height);
275 static void list_formats(AVFormatContext *ctx, int type)
277 const struct video_data *s = ctx->priv_data;
278 struct v4l2_fmtdesc vfd = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
280 while(!v4l2_ioctl(s->fd, VIDIOC_ENUM_FMT, &vfd)) {
281 enum AVCodecID codec_id = ff_fmt_v4l2codec(vfd.pixelformat);
282 enum AVPixelFormat pix_fmt = ff_fmt_v4l2ff(vfd.pixelformat, codec_id);
286 if (!(vfd.flags & V4L2_FMT_FLAG_COMPRESSED) &&
287 type & V4L_RAWFORMATS) {
288 const char *fmt_name = av_get_pix_fmt_name(pix_fmt);
289 av_log(ctx, AV_LOG_INFO, "Raw : %11s : %20s :",
290 fmt_name ? fmt_name : "Unsupported",
292 } else if (vfd.flags & V4L2_FMT_FLAG_COMPRESSED &&
293 type & V4L_COMPFORMATS) {
294 const AVCodecDescriptor *desc = avcodec_descriptor_get(codec_id);
295 av_log(ctx, AV_LOG_INFO, "Compressed: %11s : %20s :",
296 desc ? desc->name : "Unsupported",
302 #ifdef V4L2_FMT_FLAG_EMULATED
303 if (vfd.flags & V4L2_FMT_FLAG_EMULATED)
304 av_log(ctx, AV_LOG_INFO, " Emulated :");
306 #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
307 list_framesizes(ctx, vfd.pixelformat);
309 av_log(ctx, AV_LOG_INFO, "\n");
313 static void list_standards(AVFormatContext *ctx)
316 struct video_data *s = ctx->priv_data;
317 struct v4l2_standard standard;
322 for (standard.index = 0; ; standard.index++) {
323 if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
324 ret = AVERROR(errno);
325 if (ret == AVERROR(EINVAL)) {
328 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMSTD): %s\n", av_err2str(ret));
332 av_log(ctx, AV_LOG_INFO, "%2d, %16"PRIx64", %s\n",
333 standard.index, (uint64_t)standard.id, standard.name);
337 static int mmap_init(AVFormatContext *ctx)
340 struct video_data *s = ctx->priv_data;
341 struct v4l2_requestbuffers req = {
342 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
343 .count = desired_video_buffers,
344 .memory = V4L2_MEMORY_MMAP
347 if (v4l2_ioctl(s->fd, VIDIOC_REQBUFS, &req) < 0) {
348 res = AVERROR(errno);
349 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS): %s\n", av_err2str(res));
354 av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");
355 return AVERROR(ENOMEM);
357 s->buffers = req.count;
358 s->buf_start = av_malloc_array(s->buffers, sizeof(void *));
360 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
361 return AVERROR(ENOMEM);
363 s->buf_len = av_malloc_array(s->buffers, sizeof(unsigned int));
365 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
366 av_freep(&s->buf_start);
367 return AVERROR(ENOMEM);
370 for (i = 0; i < req.count; i++) {
371 struct v4l2_buffer buf = {
372 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
374 .memory = V4L2_MEMORY_MMAP
376 if (v4l2_ioctl(s->fd, VIDIOC_QUERYBUF, &buf) < 0) {
377 res = AVERROR(errno);
378 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF): %s\n", av_err2str(res));
382 s->buf_len[i] = buf.length;
383 if (s->frame_size > 0 && s->buf_len[i] < s->frame_size) {
384 av_log(ctx, AV_LOG_ERROR,
385 "buf_len[%d] = %d < expected frame size %d\n",
386 i, s->buf_len[i], s->frame_size);
387 return AVERROR(ENOMEM);
389 s->buf_start[i] = v4l2_mmap(NULL, buf.length,
390 PROT_READ | PROT_WRITE, MAP_SHARED,
391 s->fd, buf.m.offset);
393 if (s->buf_start[i] == MAP_FAILED) {
394 res = AVERROR(errno);
395 av_log(ctx, AV_LOG_ERROR, "mmap: %s\n", av_err2str(res));
403 static int enqueue_buffer(struct video_data *s, struct v4l2_buffer *buf)
407 if (v4l2_ioctl(s->fd, VIDIOC_QBUF, buf) < 0) {
408 res = AVERROR(errno);
409 av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", av_err2str(res));
411 atomic_fetch_add(&s->buffers_queued, 1);
417 static void mmap_release_buffer(void *opaque, uint8_t *data)
419 struct v4l2_buffer buf = { 0 };
420 struct buff_data *buf_descriptor = opaque;
421 struct video_data *s = buf_descriptor->s;
423 buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
424 buf.memory = V4L2_MEMORY_MMAP;
425 buf.index = buf_descriptor->index;
426 av_free(buf_descriptor);
428 enqueue_buffer(s, &buf);
431 #if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
432 static int64_t av_gettime_monotonic(void)
434 return av_gettime_relative();
438 static int init_convert_timestamp(AVFormatContext *ctx, int64_t ts)
440 struct video_data *s = ctx->priv_data;
444 if (s->ts_mode == V4L_TS_ABS &&
445 ts <= now + 1 * AV_TIME_BASE && ts >= now - 10 * AV_TIME_BASE) {
446 av_log(ctx, AV_LOG_INFO, "Detected absolute timestamps\n");
447 s->ts_mode = V4L_TS_CONVERT_READY;
450 #if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
451 if (ctx->streams[0]->avg_frame_rate.num) {
452 now = av_gettime_monotonic();
453 if (s->ts_mode == V4L_TS_MONO2ABS ||
454 (ts <= now + 1 * AV_TIME_BASE && ts >= now - 10 * AV_TIME_BASE)) {
455 AVRational tb = {AV_TIME_BASE, 1};
456 int64_t period = av_rescale_q(1, tb, ctx->streams[0]->avg_frame_rate);
457 av_log(ctx, AV_LOG_INFO, "Detected monotonic timestamps, converting\n");
458 /* microseconds instead of seconds, MHz instead of Hz */
459 s->timefilter = ff_timefilter_new(1, period, 1.0E-6);
461 return AVERROR(ENOMEM);
462 s->ts_mode = V4L_TS_CONVERT_READY;
467 av_log(ctx, AV_LOG_ERROR, "Unknown timestamps\n");
471 static int convert_timestamp(AVFormatContext *ctx, int64_t *ts)
473 struct video_data *s = ctx->priv_data;
476 int r = init_convert_timestamp(ctx, *ts);
480 #if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
482 int64_t nowa = av_gettime();
483 int64_t nowm = av_gettime_monotonic();
484 ff_timefilter_update(s->timefilter, nowa, nowm - s->last_time_m);
485 s->last_time_m = nowm;
486 *ts = ff_timefilter_eval(s->timefilter, *ts - nowm);
492 static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
494 struct video_data *s = ctx->priv_data;
495 struct v4l2_buffer buf = {
496 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
497 .memory = V4L2_MEMORY_MMAP
499 struct timeval buf_ts;
504 /* FIXME: Some special treatment might be needed in case of loss of signal... */
505 while ((res = v4l2_ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 && (errno == EINTR));
508 return AVERROR(EAGAIN);
510 res = AVERROR(errno);
511 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n",
516 buf_ts = buf.timestamp;
518 if (buf.index >= s->buffers) {
519 av_log(ctx, AV_LOG_ERROR, "Invalid buffer index received.\n");
520 return AVERROR(EINVAL);
522 atomic_fetch_add(&s->buffers_queued, -1);
523 // always keep at least one buffer queued
524 av_assert0(atomic_load(&s->buffers_queued) >= 1);
526 #ifdef V4L2_BUF_FLAG_ERROR
527 if (buf.flags & V4L2_BUF_FLAG_ERROR) {
528 av_log(ctx, AV_LOG_WARNING,
529 "Dequeued v4l2 buffer contains corrupted data (%d bytes).\n",
535 /* CPIA is a compressed format and we don't know the exact number of bytes
536 * used by a frame, so set it here as the driver announces it. */
537 if (ctx->video_codec_id == AV_CODEC_ID_CPIA)
538 s->frame_size = buf.bytesused;
540 if (s->frame_size > 0 && buf.bytesused != s->frame_size) {
541 av_log(ctx, AV_LOG_WARNING,
542 "Dequeued v4l2 buffer contains %d bytes, but %d were expected. Flags: 0x%08X.\n",
543 buf.bytesused, s->frame_size, buf.flags);
548 /* Image is at s->buff_start[buf.index] */
549 if (atomic_load(&s->buffers_queued) == FFMAX(s->buffers / 8, 1)) {
550 /* when we start getting low on queued buffers, fall back on copying data */
551 res = av_new_packet(pkt, buf.bytesused);
553 av_log(ctx, AV_LOG_ERROR, "Error allocating a packet.\n");
554 enqueue_buffer(s, &buf);
557 memcpy(pkt->data, s->buf_start[buf.index], buf.bytesused);
559 res = enqueue_buffer(s, &buf);
561 av_packet_unref(pkt);
565 struct buff_data *buf_descriptor;
567 pkt->data = s->buf_start[buf.index];
568 pkt->size = buf.bytesused;
570 buf_descriptor = av_malloc(sizeof(struct buff_data));
571 if (!buf_descriptor) {
572 /* Something went wrong... Since av_malloc() failed, we cannot even
573 * allocate a buffer for memcpying into it
575 av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
576 enqueue_buffer(s, &buf);
578 return AVERROR(ENOMEM);
580 buf_descriptor->index = buf.index;
581 buf_descriptor->s = s;
583 pkt->buf = av_buffer_create(pkt->data, pkt->size, mmap_release_buffer,
586 av_log(ctx, AV_LOG_ERROR, "Failed to create a buffer\n");
587 enqueue_buffer(s, &buf);
588 av_freep(&buf_descriptor);
589 return AVERROR(ENOMEM);
592 pkt->pts = buf_ts.tv_sec * INT64_C(1000000) + buf_ts.tv_usec;
593 convert_timestamp(ctx, &pkt->pts);
598 static int mmap_start(AVFormatContext *ctx)
600 struct video_data *s = ctx->priv_data;
601 enum v4l2_buf_type type;
604 for (i = 0; i < s->buffers; i++) {
605 struct v4l2_buffer buf = {
606 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
608 .memory = V4L2_MEMORY_MMAP
611 if (v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf) < 0) {
612 res = AVERROR(errno);
613 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n",
618 atomic_store(&s->buffers_queued, s->buffers);
620 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
621 if (v4l2_ioctl(s->fd, VIDIOC_STREAMON, &type) < 0) {
622 res = AVERROR(errno);
623 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n",
631 static void mmap_close(struct video_data *s)
633 enum v4l2_buf_type type;
636 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
637 /* We do not check for the result, because we could
638 * not do anything about it anyway...
640 v4l2_ioctl(s->fd, VIDIOC_STREAMOFF, &type);
641 for (i = 0; i < s->buffers; i++) {
642 v4l2_munmap(s->buf_start[i], s->buf_len[i]);
644 av_freep(&s->buf_start);
645 av_freep(&s->buf_len);
648 static int v4l2_set_parameters(AVFormatContext *ctx)
650 struct video_data *s = ctx->priv_data;
651 struct v4l2_standard standard = { 0 };
652 struct v4l2_streamparm streamparm = { 0 };
653 struct v4l2_fract *tpf;
654 AVRational framerate_q = { 0 };
658 (ret = av_parse_video_rate(&framerate_q, s->framerate)) < 0) {
659 av_log(ctx, AV_LOG_ERROR, "Could not parse framerate '%s'.\n",
667 av_log(ctx, AV_LOG_DEBUG, "Setting standard: %s\n", s->standard);
668 /* set tv standard */
671 if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
672 ret = AVERROR(errno);
675 if (!av_strcasecmp(standard.name, s->standard))
679 av_log(ctx, AV_LOG_ERROR, "Unknown or unsupported standard '%s'\n", s->standard);
683 if (v4l2_ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
684 ret = AVERROR(errno);
685 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_S_STD): %s\n", av_err2str(ret));
689 av_log(ctx, AV_LOG_WARNING,
690 "This device does not support any standard\n");
695 if (v4l2_ioctl(s->fd, VIDIOC_G_STD, &s->std_id) == 0) {
696 tpf = &standard.frameperiod;
699 if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
700 ret = AVERROR(errno);
701 if (ret == AVERROR(EINVAL)
703 || ret == AVERROR(ENODATA)
706 tpf = &streamparm.parm.capture.timeperframe;
709 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMSTD): %s\n", av_err2str(ret));
712 if (standard.id == s->std_id) {
713 av_log(ctx, AV_LOG_DEBUG,
714 "Current standard: %s, id: %"PRIx64", frameperiod: %d/%d\n",
715 standard.name, (uint64_t)standard.id, tpf->numerator, tpf->denominator);
720 tpf = &streamparm.parm.capture.timeperframe;
723 streamparm.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
724 if (v4l2_ioctl(s->fd, VIDIOC_G_PARM, &streamparm) < 0) {
725 ret = AVERROR(errno);
726 av_log(ctx, AV_LOG_WARNING, "ioctl(VIDIOC_G_PARM): %s\n", av_err2str(ret));
727 } else if (framerate_q.num && framerate_q.den) {
728 if (streamparm.parm.capture.capability & V4L2_CAP_TIMEPERFRAME) {
729 tpf = &streamparm.parm.capture.timeperframe;
731 av_log(ctx, AV_LOG_DEBUG, "Setting time per frame to %d/%d\n",
732 framerate_q.den, framerate_q.num);
733 tpf->numerator = framerate_q.den;
734 tpf->denominator = framerate_q.num;
736 if (v4l2_ioctl(s->fd, VIDIOC_S_PARM, &streamparm) < 0) {
737 ret = AVERROR(errno);
738 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_S_PARM): %s\n",
743 if (framerate_q.num != tpf->denominator ||
744 framerate_q.den != tpf->numerator) {
745 av_log(ctx, AV_LOG_INFO,
746 "The driver changed the time per frame from "
748 framerate_q.den, framerate_q.num,
749 tpf->numerator, tpf->denominator);
752 av_log(ctx, AV_LOG_WARNING,
753 "The driver does not permit changing the time per frame\n");
756 if (tpf->denominator > 0 && tpf->numerator > 0) {
757 ctx->streams[0]->avg_frame_rate.num = tpf->denominator;
758 ctx->streams[0]->avg_frame_rate.den = tpf->numerator;
759 ctx->streams[0]->r_frame_rate = ctx->streams[0]->avg_frame_rate;
761 av_log(ctx, AV_LOG_WARNING, "Time per frame unknown\n");
766 static int device_try_init(AVFormatContext *ctx,
767 enum AVPixelFormat pix_fmt,
770 uint32_t *desired_format,
771 enum AVCodecID *codec_id)
775 *desired_format = ff_fmt_ff2v4l(pix_fmt, ctx->video_codec_id);
777 if (*desired_format) {
778 ret = device_init(ctx, width, height, *desired_format);
781 if (ret != AVERROR(EINVAL))
786 if (!*desired_format) {
787 for (i = 0; ff_fmt_conversion_table[i].codec_id != AV_CODEC_ID_NONE; i++) {
788 if (ctx->video_codec_id == AV_CODEC_ID_NONE ||
789 ff_fmt_conversion_table[i].codec_id == ctx->video_codec_id) {
790 av_log(ctx, AV_LOG_DEBUG, "Trying to set codec:%s pix_fmt:%s\n",
791 avcodec_get_name(ff_fmt_conversion_table[i].codec_id),
792 (char *)av_x_if_null(av_get_pix_fmt_name(ff_fmt_conversion_table[i].ff_fmt), "none"));
794 *desired_format = ff_fmt_conversion_table[i].v4l2_fmt;
795 ret = device_init(ctx, width, height, *desired_format);
798 else if (ret != AVERROR(EINVAL))
804 if (*desired_format == 0) {
805 av_log(ctx, AV_LOG_ERROR, "Cannot find a proper format for "
806 "codec '%s' (id %d), pixel format '%s' (id %d)\n",
807 avcodec_get_name(ctx->video_codec_id), ctx->video_codec_id,
808 (char *)av_x_if_null(av_get_pix_fmt_name(pix_fmt), "none"), pix_fmt);
809 ret = AVERROR(EINVAL);
813 *codec_id = ff_fmt_v4l2codec(*desired_format);
814 if (*codec_id == AV_CODEC_ID_NONE)
815 av_assert0(ret == AVERROR(EINVAL));
819 static int v4l2_read_probe(const AVProbeData *p)
821 if (av_strstart(p->filename, "/dev/video", NULL))
822 return AVPROBE_SCORE_MAX - 1;
826 static int v4l2_read_header(AVFormatContext *ctx)
828 struct video_data *s = ctx->priv_data;
831 uint32_t desired_format;
832 enum AVCodecID codec_id = AV_CODEC_ID_NONE;
833 enum AVPixelFormat pix_fmt = AV_PIX_FMT_NONE;
834 struct v4l2_input input = { 0 };
836 st = avformat_new_stream(ctx, NULL);
838 return AVERROR(ENOMEM);
841 /* silence libv4l2 logging. if fopen() fails v4l2_log_file will be NULL
842 and errors will get sent to stderr */
844 v4l2_log_file = fopen("/dev/null", "w");
847 s->fd = device_open(ctx, ctx->url);
851 if (s->channel != -1) {
852 /* set video input */
853 av_log(ctx, AV_LOG_DEBUG, "Selecting input_channel: %d\n", s->channel);
854 if (v4l2_ioctl(s->fd, VIDIOC_S_INPUT, &s->channel) < 0) {
855 res = AVERROR(errno);
856 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_S_INPUT): %s\n", av_err2str(res));
860 /* get current video input */
861 if (v4l2_ioctl(s->fd, VIDIOC_G_INPUT, &s->channel) < 0) {
862 res = AVERROR(errno);
863 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_G_INPUT): %s\n", av_err2str(res));
869 input.index = s->channel;
870 if (v4l2_ioctl(s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
871 res = AVERROR(errno);
872 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMINPUT): %s\n", av_err2str(res));
875 s->std_id = input.std;
876 av_log(ctx, AV_LOG_DEBUG, "Current input_channel: %d, input_name: %s, input_std: %"PRIx64"\n",
877 s->channel, input.name, (uint64_t)input.std);
879 if (s->list_format) {
880 list_formats(ctx, s->list_format);
885 if (s->list_standard) {
891 avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
893 if (s->pixel_format) {
894 const AVCodecDescriptor *desc = avcodec_descriptor_get_by_name(s->pixel_format);
897 ctx->video_codec_id = desc->id;
899 pix_fmt = av_get_pix_fmt(s->pixel_format);
901 if (pix_fmt == AV_PIX_FMT_NONE && !desc) {
902 av_log(ctx, AV_LOG_ERROR, "No such input format: %s.\n",
905 res = AVERROR(EINVAL);
910 if (!s->width && !s->height) {
911 struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
913 av_log(ctx, AV_LOG_VERBOSE,
914 "Querying the device for the current frame size\n");
915 if (v4l2_ioctl(s->fd, VIDIOC_G_FMT, &fmt) < 0) {
916 res = AVERROR(errno);
917 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n",
922 s->width = fmt.fmt.pix.width;
923 s->height = fmt.fmt.pix.height;
924 av_log(ctx, AV_LOG_VERBOSE,
925 "Setting frame size to %dx%d\n", s->width, s->height);
928 res = device_try_init(ctx, pix_fmt, &s->width, &s->height, &desired_format, &codec_id);
932 /* If no pixel_format was specified, the codec_id was not known up
933 * until now. Set video_codec_id in the context, as codec_id will
934 * not be available outside this function
936 if (codec_id != AV_CODEC_ID_NONE && ctx->video_codec_id == AV_CODEC_ID_NONE)
937 ctx->video_codec_id = codec_id;
939 if ((res = av_image_check_size(s->width, s->height, 0, ctx)) < 0)
942 s->pixelformat = desired_format;
944 if ((res = v4l2_set_parameters(ctx)) < 0)
947 st->codecpar->format = ff_fmt_v4l2ff(desired_format, codec_id);
948 if (st->codecpar->format != AV_PIX_FMT_NONE)
949 s->frame_size = av_image_get_buffer_size(st->codecpar->format,
950 s->width, s->height, 1);
952 if ((res = mmap_init(ctx)) ||
953 (res = mmap_start(ctx)) < 0)
956 s->top_field_first = first_field(s);
958 st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
959 st->codecpar->codec_id = codec_id;
960 if (codec_id == AV_CODEC_ID_RAWVIDEO)
961 st->codecpar->codec_tag =
962 avcodec_pix_fmt_to_codec_tag(st->codecpar->format);
963 else if (codec_id == AV_CODEC_ID_H264) {
964 st->need_parsing = AVSTREAM_PARSE_FULL_ONCE;
966 if (desired_format == V4L2_PIX_FMT_YVU420)
967 st->codecpar->codec_tag = MKTAG('Y', 'V', '1', '2');
968 else if (desired_format == V4L2_PIX_FMT_YVU410)
969 st->codecpar->codec_tag = MKTAG('Y', 'V', 'U', '9');
970 st->codecpar->width = s->width;
971 st->codecpar->height = s->height;
972 if (st->avg_frame_rate.den)
973 st->codecpar->bit_rate = s->frame_size * av_q2d(st->avg_frame_rate) * 8;
982 static int v4l2_read_packet(AVFormatContext *ctx, AVPacket *pkt)
984 #if FF_API_CODED_FRAME && FF_API_LAVF_AVCTX
985 FF_DISABLE_DEPRECATION_WARNINGS
986 struct video_data *s = ctx->priv_data;
987 AVFrame *frame = ctx->streams[0]->codec->coded_frame;
988 FF_ENABLE_DEPRECATION_WARNINGS
992 if ((res = mmap_read_frame(ctx, pkt)) < 0) {
996 #if FF_API_CODED_FRAME && FF_API_LAVF_AVCTX
997 FF_DISABLE_DEPRECATION_WARNINGS
998 if (frame && s->interlaced) {
999 frame->interlaced_frame = 1;
1000 frame->top_field_first = s->top_field_first;
1002 FF_ENABLE_DEPRECATION_WARNINGS
1008 static int v4l2_read_close(AVFormatContext *ctx)
1010 struct video_data *s = ctx->priv_data;
1012 if (atomic_load(&s->buffers_queued) != s->buffers)
1013 av_log(ctx, AV_LOG_WARNING, "Some buffers are still owned by the caller on "
1022 static int v4l2_is_v4l_dev(const char *name)
1024 return !strncmp(name, "video", 5) ||
1025 !strncmp(name, "radio", 5) ||
1026 !strncmp(name, "vbi", 3) ||
1027 !strncmp(name, "v4l-subdev", 10);
1030 static int v4l2_get_device_list(AVFormatContext *ctx, AVDeviceInfoList *device_list)
1032 struct video_data *s = ctx->priv_data;
1034 struct dirent *entry;
1035 AVDeviceInfo *device = NULL;
1036 struct v4l2_capability cap;
1040 return AVERROR(EINVAL);
1042 dir = opendir("/dev");
1044 ret = AVERROR(errno);
1045 av_log(ctx, AV_LOG_ERROR, "Couldn't open the directory: %s\n", av_err2str(ret));
1048 while ((entry = readdir(dir))) {
1049 char device_name[256];
1051 if (!v4l2_is_v4l_dev(entry->d_name))
1054 snprintf(device_name, sizeof(device_name), "/dev/%s", entry->d_name);
1055 if ((s->fd = device_open(ctx, device_name)) < 0)
1058 if (v4l2_ioctl(s->fd, VIDIOC_QUERYCAP, &cap) < 0) {
1059 ret = AVERROR(errno);
1060 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n", av_err2str(ret));
1064 device = av_mallocz(sizeof(AVDeviceInfo));
1066 ret = AVERROR(ENOMEM);
1069 device->device_name = av_strdup(device_name);
1070 device->device_description = av_strdup(cap.card);
1071 if (!device->device_name || !device->device_description) {
1072 ret = AVERROR(ENOMEM);
1076 if ((ret = av_dynarray_add_nofree(&device_list->devices,
1077 &device_list->nb_devices, device)) < 0)
1086 av_freep(&device->device_name);
1087 av_freep(&device->device_description);
1099 #define OFFSET(x) offsetof(struct video_data, x)
1100 #define DEC AV_OPT_FLAG_DECODING_PARAM
1102 static const AVOption options[] = {
1103 { "standard", "set TV standard, used only by analog frame grabber", OFFSET(standard), AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, DEC },
1104 { "channel", "set TV channel, used only by frame grabber", OFFSET(channel), AV_OPT_TYPE_INT, {.i64 = -1 }, -1, INT_MAX, DEC },
1105 { "video_size", "set frame size", OFFSET(width), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, DEC },
1106 { "pixel_format", "set preferred pixel format", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
1107 { "input_format", "set preferred pixel format (for raw video) or codec name", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
1108 { "framerate", "set frame rate", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
1110 { "list_formats", "list available formats and exit", OFFSET(list_format), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, DEC, "list_formats" },
1111 { "all", "show all available formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_ALLFORMATS }, 0, INT_MAX, DEC, "list_formats" },
1112 { "raw", "show only non-compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_RAWFORMATS }, 0, INT_MAX, DEC, "list_formats" },
1113 { "compressed", "show only compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_COMPFORMATS }, 0, INT_MAX, DEC, "list_formats" },
1115 { "list_standards", "list supported standards and exit", OFFSET(list_standard), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 1, DEC, "list_standards" },
1116 { "all", "show all supported standards", OFFSET(list_standard), AV_OPT_TYPE_CONST, {.i64 = 1 }, 0, 0, DEC, "list_standards" },
1118 { "timestamps", "set type of timestamps for grabbed frames", OFFSET(ts_mode), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 2, DEC, "timestamps" },
1119 { "ts", "set type of timestamps for grabbed frames", OFFSET(ts_mode), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 2, DEC, "timestamps" },
1120 { "default", "use timestamps from the kernel", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.i64 = V4L_TS_DEFAULT }, 0, 2, DEC, "timestamps" },
1121 { "abs", "use absolute timestamps (wall clock)", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.i64 = V4L_TS_ABS }, 0, 2, DEC, "timestamps" },
1122 { "mono2abs", "force conversion from monotonic to absolute timestamps", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.i64 = V4L_TS_MONO2ABS }, 0, 2, DEC, "timestamps" },
1123 { "use_libv4l2", "use libv4l2 (v4l-utils) conversion functions", OFFSET(use_libv4l2), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, DEC },
1127 static const AVClass v4l2_class = {
1128 .class_name = "V4L2 indev",
1129 .item_name = av_default_item_name,
1131 .version = LIBAVUTIL_VERSION_INT,
1132 .category = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
1135 AVInputFormat ff_v4l2_demuxer = {
1136 .name = "video4linux2,v4l2",
1137 .long_name = NULL_IF_CONFIG_SMALL("Video4Linux2 device grab"),
1138 .priv_data_size = sizeof(struct video_data),
1139 .read_probe = v4l2_read_probe,
1140 .read_header = v4l2_read_header,
1141 .read_packet = v4l2_read_packet,
1142 .read_close = v4l2_read_close,
1143 .get_device_list = v4l2_get_device_list,
1144 .flags = AVFMT_NOFILE,
1145 .priv_class = &v4l2_class,