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 "v4l2-common.h"
39 static const int desired_video_buffers = 256;
41 #define V4L_ALLFORMATS 3
42 #define V4L_RAWFORMATS 1
43 #define V4L_COMPFORMATS 2
46 * Return timestamps to the user exactly as returned by the kernel
48 #define V4L_TS_DEFAULT 0
50 * Autodetect the kind of timestamps returned by the kernel and convert to
51 * absolute (wall clock) timestamps.
55 * Assume kernel timestamps are from the monotonic clock and convert to
56 * absolute timestamps.
58 #define V4L_TS_MONO2ABS 2
61 * Once the kind of timestamps returned by the kernel have been detected,
62 * the value of the timefilter (NULL or not) determines whether a conversion
65 #define V4L_TS_CONVERT_READY V4L_TS_DEFAULT
70 int frame_format; /* V4L2_PIX_FMT_* */
76 TimeFilter *timefilter;
80 volatile int buffers_queued;
82 unsigned int *buf_len;
86 char *pixel_format; /**< Set by a private option. */
87 int list_format; /**< Set by a private option. */
88 int list_standard; /**< Set by a private option. */
89 char *framerate; /**< Set by a private option. */
92 int (*open_f)(const char *file, int oflag, ...);
93 int (*close_f)(int fd);
95 int (*ioctl_f)(int fd, unsigned long int request, ...);
96 ssize_t (*read_f)(int fd, void *buffer, size_t n);
97 void *(*mmap_f)(void *start, size_t length, int prot, int flags, int fd, int64_t offset);
98 int (*munmap_f)(void *_start, size_t length);
102 struct video_data *s;
106 static int device_open(AVFormatContext *ctx)
108 struct video_data *s = ctx->priv_data;
109 struct v4l2_capability cap;
114 #define SET_WRAPPERS(prefix) do { \
115 s->open_f = prefix ## open; \
116 s->close_f = prefix ## close; \
117 s->dup_f = prefix ## dup; \
118 s->ioctl_f = prefix ## ioctl; \
119 s->read_f = prefix ## read; \
120 s->mmap_f = prefix ## mmap; \
121 s->munmap_f = prefix ## munmap; \
124 if (s->use_libv4l2) {
128 av_log(ctx, AV_LOG_ERROR, "libavdevice is not build with libv4l2 support.\n");
129 return AVERROR(EINVAL);
135 #define v4l2_open s->open_f
136 #define v4l2_close s->close_f
137 #define v4l2_dup s->dup_f
138 #define v4l2_ioctl s->ioctl_f
139 #define v4l2_read s->read_f
140 #define v4l2_mmap s->mmap_f
141 #define v4l2_munmap s->munmap_f
143 if (ctx->flags & AVFMT_FLAG_NONBLOCK) {
147 fd = v4l2_open(ctx->filename, flags, 0);
149 ret = AVERROR(errno);
150 av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s: %s\n",
151 ctx->filename, av_err2str(ret));
155 if (v4l2_ioctl(fd, VIDIOC_QUERYCAP, &cap) < 0) {
156 ret = AVERROR(errno);
157 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
162 av_log(ctx, AV_LOG_VERBOSE, "fd:%d capabilities:%x\n",
163 fd, cap.capabilities);
165 if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {
166 av_log(ctx, AV_LOG_ERROR, "Not a video capture device.\n");
167 ret = AVERROR(ENODEV);
171 if (!(cap.capabilities & V4L2_CAP_STREAMING)) {
172 av_log(ctx, AV_LOG_ERROR,
173 "The device does not support the streaming I/O method.\n");
174 ret = AVERROR(ENOSYS);
185 static int device_init(AVFormatContext *ctx, int *width, int *height,
188 struct video_data *s = ctx->priv_data;
190 struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
191 struct v4l2_pix_format *pix = &fmt.fmt.pix;
196 pix->height = *height;
197 pix->pixelformat = pix_fmt;
198 pix->field = V4L2_FIELD_ANY;
200 if (v4l2_ioctl(fd, VIDIOC_S_FMT, &fmt) < 0)
201 res = AVERROR(errno);
203 if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {
204 av_log(ctx, AV_LOG_INFO,
205 "The V4L2 driver changed the video from %dx%d to %dx%d\n",
206 *width, *height, fmt.fmt.pix.width, fmt.fmt.pix.height);
207 *width = fmt.fmt.pix.width;
208 *height = fmt.fmt.pix.height;
211 if (pix_fmt != fmt.fmt.pix.pixelformat) {
212 av_log(ctx, AV_LOG_DEBUG,
213 "The V4L2 driver changed the pixel format "
214 "from 0x%08X to 0x%08X\n",
215 pix_fmt, fmt.fmt.pix.pixelformat);
216 res = AVERROR(EINVAL);
219 if (fmt.fmt.pix.field == V4L2_FIELD_INTERLACED) {
220 av_log(ctx, AV_LOG_DEBUG,
221 "The V4L2 driver is using the interlaced mode\n");
228 static int first_field(const struct video_data *s, int fd)
233 res = v4l2_ioctl(fd, VIDIOC_G_STD, &std);
237 if (std & V4L2_STD_NTSC) {
244 #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
245 static void list_framesizes(AVFormatContext *ctx, int fd, uint32_t pixelformat)
247 const struct video_data *s = ctx->priv_data;
248 struct v4l2_frmsizeenum vfse = { .pixel_format = pixelformat };
250 while(!v4l2_ioctl(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 fd, 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(fd, VIDIOC_ENUM_FMT, &vfd)) {
277 enum AVCodecID codec_id = avpriv_fmt_v4l2codec(vfd.pixelformat);
278 enum AVPixelFormat pix_fmt = avpriv_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 : %9s : %20s :",
286 fmt_name ? fmt_name : "Unsupported",
288 } else if (vfd.flags & V4L2_FMT_FLAG_COMPRESSED &&
289 type & V4L_COMPFORMATS) {
290 AVCodec *codec = avcodec_find_decoder(codec_id);
291 av_log(ctx, AV_LOG_INFO, "Compressed: %9s : %20s :",
292 codec ? codec->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, fd, 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_free(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 #if FF_API_DESTRUCT_PACKET
400 static void dummy_release_buffer(AVPacket *pkt)
406 static void mmap_release_buffer(void *opaque, uint8_t *data)
408 struct v4l2_buffer buf = { 0 };
410 struct buff_data *buf_descriptor = opaque;
411 struct video_data *s = buf_descriptor->s;
413 buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
414 buf.memory = V4L2_MEMORY_MMAP;
415 buf.index = buf_descriptor->index;
416 av_free(buf_descriptor);
418 if (v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf) < 0) {
419 res = AVERROR(errno);
420 av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n",
424 avpriv_atomic_int_add_and_fetch(&s->buffers_queued, 1);
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
497 /* FIXME: Some special treatment might be needed in case of loss of signal... */
498 while ((res = v4l2_ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 && (errno == EINTR));
500 if (errno == EAGAIN) {
502 return AVERROR(EAGAIN);
504 res = AVERROR(errno);
505 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n", av_err2str(res));
509 if (buf.index >= s->buffers) {
510 av_log(ctx, AV_LOG_ERROR, "Invalid buffer index received.\n");
511 return AVERROR(EINVAL);
513 avpriv_atomic_int_add_and_fetch(&s->buffers_queued, -1);
514 // always keep at least one buffer queued
515 av_assert0(avpriv_atomic_int_get(&s->buffers_queued) >= 1);
517 /* CPIA is a compressed format and we don't know the exact number of bytes
518 * used by a frame, so set it here as the driver announces it.
520 if (ctx->video_codec_id == AV_CODEC_ID_CPIA)
521 s->frame_size = buf.bytesused;
523 if (s->frame_size > 0 && buf.bytesused != s->frame_size) {
524 av_log(ctx, AV_LOG_ERROR,
525 "The v4l2 frame is %d bytes, but %d bytes are expected\n",
526 buf.bytesused, s->frame_size);
527 return AVERROR_INVALIDDATA;
530 /* Image is at s->buff_start[buf.index] */
531 if (avpriv_atomic_int_get(&s->buffers_queued) == FFMAX(s->buffers / 8, 1)) {
532 /* when we start getting low on queued buffers, fall back on copying data */
533 res = av_new_packet(pkt, buf.bytesused);
535 av_log(ctx, AV_LOG_ERROR, "Error allocating a packet.\n");
536 if (v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf) == 0)
537 avpriv_atomic_int_add_and_fetch(&s->buffers_queued, 1);
540 memcpy(pkt->data, s->buf_start[buf.index], buf.bytesused);
542 if (v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf) < 0) {
543 res = AVERROR(errno);
544 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", av_err2str(res));
548 avpriv_atomic_int_add_and_fetch(&s->buffers_queued, 1);
550 struct buff_data *buf_descriptor;
552 pkt->data = s->buf_start[buf.index];
553 pkt->size = buf.bytesused;
554 #if FF_API_DESTRUCT_PACKET
555 FF_DISABLE_DEPRECATION_WARNINGS
556 pkt->destruct = dummy_release_buffer;
557 FF_ENABLE_DEPRECATION_WARNINGS
560 buf_descriptor = av_malloc(sizeof(struct buff_data));
561 if (!buf_descriptor) {
562 /* Something went wrong... Since av_malloc() failed, we cannot even
563 * allocate a buffer for memcpying into it
565 av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
566 if (v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf) == 0)
567 avpriv_atomic_int_add_and_fetch(&s->buffers_queued, 1);
569 return AVERROR(ENOMEM);
571 buf_descriptor->index = buf.index;
572 buf_descriptor->s = s;
574 pkt->buf = av_buffer_create(pkt->data, pkt->size, mmap_release_buffer,
577 av_log(ctx, AV_LOG_ERROR, "Failed to create a buffer\n");
578 if (v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf) == 0)
579 avpriv_atomic_int_add_and_fetch(&s->buffers_queued, 1);
580 av_freep(&buf_descriptor);
581 return AVERROR(ENOMEM);
584 pkt->pts = buf.timestamp.tv_sec * INT64_C(1000000) + buf.timestamp.tv_usec;
585 convert_timestamp(ctx, &pkt->pts);
587 return s->buf_len[buf.index];
590 static int mmap_start(AVFormatContext *ctx)
592 struct video_data *s = ctx->priv_data;
593 enum v4l2_buf_type type;
596 for (i = 0; i < s->buffers; i++) {
597 struct v4l2_buffer buf = {
598 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
600 .memory = V4L2_MEMORY_MMAP
603 if (v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf) < 0) {
604 res = AVERROR(errno);
605 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", av_err2str(res));
609 s->buffers_queued = s->buffers;
611 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
612 if (v4l2_ioctl(s->fd, VIDIOC_STREAMON, &type) < 0) {
613 res = AVERROR(errno);
614 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n", av_err2str(res));
621 static void mmap_close(struct video_data *s)
623 enum v4l2_buf_type type;
626 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
627 /* We do not check for the result, because we could
628 * not do anything about it anyway...
630 v4l2_ioctl(s->fd, VIDIOC_STREAMOFF, &type);
631 for (i = 0; i < s->buffers; i++) {
632 v4l2_munmap(s->buf_start[i], s->buf_len[i]);
634 av_free(s->buf_start);
638 static int v4l2_set_parameters(AVFormatContext *s1)
640 struct video_data *s = s1->priv_data;
641 struct v4l2_standard standard = { 0 };
642 struct v4l2_streamparm streamparm = { 0 };
643 struct v4l2_fract *tpf;
644 AVRational framerate_q = { 0 };
648 (ret = av_parse_video_rate(&framerate_q, s->framerate)) < 0) {
649 av_log(s1, AV_LOG_ERROR, "Could not parse framerate '%s'.\n",
657 av_log(s1, AV_LOG_DEBUG, "Setting standard: %s\n", s->standard);
658 /* set tv standard */
661 if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
662 ret = AVERROR(errno);
665 if (!av_strcasecmp(standard.name, s->standard))
669 av_log(s1, AV_LOG_ERROR, "Unknown or unsupported standard '%s'\n", s->standard);
673 if (v4l2_ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
674 ret = AVERROR(errno);
675 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_S_STD): %s\n", av_err2str(ret));
679 av_log(s1, AV_LOG_WARNING,
680 "This device does not support any standard\n");
685 if (v4l2_ioctl(s->fd, VIDIOC_G_STD, &s->std_id) == 0) {
686 tpf = &standard.frameperiod;
689 if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
690 ret = AVERROR(errno);
691 if (ret == AVERROR(EINVAL)
693 || ret == AVERROR(ENODATA)
696 tpf = &streamparm.parm.capture.timeperframe;
699 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMSTD): %s\n", av_err2str(ret));
702 if (standard.id == s->std_id) {
703 av_log(s1, AV_LOG_DEBUG,
704 "Current standard: %s, id: %"PRIx64", frameperiod: %d/%d\n",
705 standard.name, (uint64_t)standard.id, tpf->numerator, tpf->denominator);
710 tpf = &streamparm.parm.capture.timeperframe;
713 streamparm.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
714 if (v4l2_ioctl(s->fd, VIDIOC_G_PARM, &streamparm) < 0) {
715 ret = AVERROR(errno);
716 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_PARM): %s\n", av_err2str(ret));
720 if (framerate_q.num && framerate_q.den) {
721 if (streamparm.parm.capture.capability & V4L2_CAP_TIMEPERFRAME) {
722 tpf = &streamparm.parm.capture.timeperframe;
724 av_log(s1, AV_LOG_DEBUG, "Setting time per frame to %d/%d\n",
725 framerate_q.den, framerate_q.num);
726 tpf->numerator = framerate_q.den;
727 tpf->denominator = framerate_q.num;
729 if (v4l2_ioctl(s->fd, VIDIOC_S_PARM, &streamparm) < 0) {
730 ret = AVERROR(errno);
731 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_S_PARM): %s\n", av_err2str(ret));
735 if (framerate_q.num != tpf->denominator ||
736 framerate_q.den != tpf->numerator) {
737 av_log(s1, AV_LOG_INFO,
738 "The driver changed the time per frame from "
740 framerate_q.den, framerate_q.num,
741 tpf->numerator, tpf->denominator);
744 av_log(s1, AV_LOG_WARNING,
745 "The driver does not allow to change time per frame\n");
748 if (tpf->denominator > 0 && tpf->numerator > 0) {
749 s1->streams[0]->avg_frame_rate.num = tpf->denominator;
750 s1->streams[0]->avg_frame_rate.den = tpf->numerator;
751 s1->streams[0]->r_frame_rate = s1->streams[0]->avg_frame_rate;
753 av_log(s1, AV_LOG_WARNING, "Time per frame unknown\n");
758 static int device_try_init(AVFormatContext *s1,
759 enum AVPixelFormat pix_fmt,
762 uint32_t *desired_format,
763 enum AVCodecID *codec_id)
767 *desired_format = avpriv_fmt_ff2v4l(pix_fmt, s1->video_codec_id);
769 if (*desired_format) {
770 ret = device_init(s1, width, height, *desired_format);
773 if (ret != AVERROR(EINVAL))
778 if (!*desired_format) {
779 for (i = 0; avpriv_fmt_conversion_table[i].codec_id != AV_CODEC_ID_NONE; i++) {
780 if (s1->video_codec_id == AV_CODEC_ID_NONE ||
781 avpriv_fmt_conversion_table[i].codec_id == s1->video_codec_id) {
782 av_log(s1, AV_LOG_DEBUG, "Trying to set codec:%s pix_fmt:%s\n",
783 avcodec_get_name(avpriv_fmt_conversion_table[i].codec_id),
784 (char *)av_x_if_null(av_get_pix_fmt_name(avpriv_fmt_conversion_table[i].ff_fmt), "none"));
786 *desired_format = avpriv_fmt_conversion_table[i].v4l2_fmt;
787 ret = device_init(s1, width, height, *desired_format);
790 else if (ret != AVERROR(EINVAL))
796 if (*desired_format == 0) {
797 av_log(s1, AV_LOG_ERROR, "Cannot find a proper format for "
798 "codec '%s' (id %d), pixel format '%s' (id %d)\n",
799 avcodec_get_name(s1->video_codec_id), s1->video_codec_id,
800 (char *)av_x_if_null(av_get_pix_fmt_name(pix_fmt), "none"), pix_fmt);
801 ret = AVERROR(EINVAL);
805 *codec_id = avpriv_fmt_v4l2codec(*desired_format);
806 av_assert0(*codec_id != AV_CODEC_ID_NONE);
810 static int v4l2_read_header(AVFormatContext *s1)
812 struct video_data *s = s1->priv_data;
815 uint32_t desired_format;
816 enum AVCodecID codec_id = AV_CODEC_ID_NONE;
817 enum AVPixelFormat pix_fmt = AV_PIX_FMT_NONE;
818 struct v4l2_input input = { 0 };
820 st = avformat_new_stream(s1, NULL);
822 return AVERROR(ENOMEM);
825 /* silence libv4l2 logging. if fopen() fails v4l2_log_file will be NULL
826 and errors will get sent to stderr */
828 v4l2_log_file = fopen("/dev/null", "w");
831 s->fd = device_open(s1);
835 if (s->channel != -1) {
836 /* set video input */
837 av_log(s1, AV_LOG_DEBUG, "Selecting input_channel: %d\n", s->channel);
838 if (v4l2_ioctl(s->fd, VIDIOC_S_INPUT, &s->channel) < 0) {
839 res = AVERROR(errno);
840 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_S_INPUT): %s\n", av_err2str(res));
844 /* get current video input */
845 if (v4l2_ioctl(s->fd, VIDIOC_G_INPUT, &s->channel) < 0) {
846 res = AVERROR(errno);
847 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_INPUT): %s\n", av_err2str(res));
853 input.index = s->channel;
854 if (v4l2_ioctl(s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
855 res = AVERROR(errno);
856 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMINPUT): %s\n", av_err2str(res));
859 s->std_id = input.std;
860 av_log(s1, AV_LOG_DEBUG, "Current input_channel: %d, input_name: %s, input_std: %"PRIx64"\n",
861 s->channel, input.name, (uint64_t)input.std);
863 if (s->list_format) {
864 list_formats(s1, s->fd, s->list_format);
869 if (s->list_standard) {
875 avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
877 if ((res = v4l2_set_parameters(s1)) < 0)
880 if (s->pixel_format) {
881 AVCodec *codec = avcodec_find_decoder_by_name(s->pixel_format);
884 s1->video_codec_id = codec->id;
886 pix_fmt = av_get_pix_fmt(s->pixel_format);
888 if (pix_fmt == AV_PIX_FMT_NONE && !codec) {
889 av_log(s1, AV_LOG_ERROR, "No such input format: %s.\n",
892 res = AVERROR(EINVAL);
897 if (!s->width && !s->height) {
898 struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
900 av_log(s1, AV_LOG_VERBOSE,
901 "Querying the device for the current frame size\n");
902 if (v4l2_ioctl(s->fd, VIDIOC_G_FMT, &fmt) < 0) {
903 res = AVERROR(errno);
904 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n", av_err2str(res));
908 s->width = fmt.fmt.pix.width;
909 s->height = fmt.fmt.pix.height;
910 av_log(s1, AV_LOG_VERBOSE,
911 "Setting frame size to %dx%d\n", s->width, s->height);
914 res = device_try_init(s1, pix_fmt, &s->width, &s->height, &desired_format, &codec_id);
918 /* If no pixel_format was specified, the codec_id was not known up
919 * until now. Set video_codec_id in the context, as codec_id will
920 * not be available outside this function
922 if (codec_id != AV_CODEC_ID_NONE && s1->video_codec_id == AV_CODEC_ID_NONE)
923 s1->video_codec_id = codec_id;
925 if ((res = av_image_check_size(s->width, s->height, 0, s1)) < 0)
928 s->frame_format = desired_format;
930 st->codec->pix_fmt = avpriv_fmt_v4l2ff(desired_format, codec_id);
932 avpicture_get_size(st->codec->pix_fmt, s->width, s->height);
934 if ((res = mmap_init(s1)) ||
935 (res = mmap_start(s1)) < 0)
938 s->top_field_first = first_field(s, s->fd);
940 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
941 st->codec->codec_id = codec_id;
942 if (codec_id == AV_CODEC_ID_RAWVIDEO)
943 st->codec->codec_tag =
944 avcodec_pix_fmt_to_codec_tag(st->codec->pix_fmt);
945 else if (codec_id == AV_CODEC_ID_H264) {
946 st->need_parsing = AVSTREAM_PARSE_HEADERS;
948 if (desired_format == V4L2_PIX_FMT_YVU420)
949 st->codec->codec_tag = MKTAG('Y', 'V', '1', '2');
950 else if (desired_format == V4L2_PIX_FMT_YVU410)
951 st->codec->codec_tag = MKTAG('Y', 'V', 'U', '9');
952 st->codec->width = s->width;
953 st->codec->height = s->height;
954 if (st->avg_frame_rate.den)
955 st->codec->bit_rate = s->frame_size * av_q2d(st->avg_frame_rate) * 8;
964 static int v4l2_read_packet(AVFormatContext *s1, AVPacket *pkt)
966 struct video_data *s = s1->priv_data;
967 AVFrame *frame = s1->streams[0]->codec->coded_frame;
971 if ((res = mmap_read_frame(s1, pkt)) < 0) {
975 if (frame && s->interlaced) {
976 frame->interlaced_frame = 1;
977 frame->top_field_first = s->top_field_first;
983 static int v4l2_read_close(AVFormatContext *s1)
985 struct video_data *s = s1->priv_data;
987 if (avpriv_atomic_int_get(&s->buffers_queued) != s->buffers)
988 av_log(s1, AV_LOG_WARNING, "Some buffers are still owned by the caller on "
997 #define OFFSET(x) offsetof(struct video_data, x)
998 #define DEC AV_OPT_FLAG_DECODING_PARAM
1000 static const AVOption options[] = {
1001 { "standard", "set TV standard, used only by analog frame grabber", OFFSET(standard), AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, DEC },
1002 { "channel", "set TV channel, used only by frame grabber", OFFSET(channel), AV_OPT_TYPE_INT, {.i64 = -1 }, -1, INT_MAX, DEC },
1003 { "video_size", "set frame size", OFFSET(width), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, DEC },
1004 { "pixel_format", "set preferred pixel format", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
1005 { "input_format", "set preferred pixel format (for raw video) or codec name", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
1006 { "framerate", "set frame rate", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
1008 { "list_formats", "list available formats and exit", OFFSET(list_format), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, DEC, "list_formats" },
1009 { "all", "show all available formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_ALLFORMATS }, 0, INT_MAX, DEC, "list_formats" },
1010 { "raw", "show only non-compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_RAWFORMATS }, 0, INT_MAX, DEC, "list_formats" },
1011 { "compressed", "show only compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_COMPFORMATS }, 0, INT_MAX, DEC, "list_formats" },
1013 { "list_standards", "list supported standards and exit", OFFSET(list_standard), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 1, DEC, "list_standards" },
1014 { "all", "show all supported standards", OFFSET(list_standard), AV_OPT_TYPE_CONST, {.i64 = 1 }, 0, 0, DEC, "list_standards" },
1016 { "timestamps", "set type of timestamps for grabbed frames", OFFSET(ts_mode), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 2, DEC, "timestamps" },
1017 { "ts", "set type of timestamps for grabbed frames", OFFSET(ts_mode), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 2, DEC, "timestamps" },
1018 { "default", "use timestamps from the kernel", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.i64 = V4L_TS_DEFAULT }, 0, 2, DEC, "timestamps" },
1019 { "abs", "use absolute timestamps (wall clock)", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.i64 = V4L_TS_ABS }, 0, 2, DEC, "timestamps" },
1020 { "mono2abs", "force conversion from monotonic to absolute timestamps", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.i64 = V4L_TS_MONO2ABS }, 0, 2, DEC, "timestamps" },
1021 { "use_libv4l2", "use libv4l2 (v4l-utils) conversion functions", OFFSET(use_libv4l2), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, DEC },
1025 static const AVClass v4l2_class = {
1026 .class_name = "V4L2 indev",
1027 .item_name = av_default_item_name,
1029 .version = LIBAVUTIL_VERSION_INT,
1030 .category = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
1033 AVInputFormat ff_v4l2_demuxer = {
1034 .name = "video4linux2,v4l2",
1035 .long_name = NULL_IF_CONFIG_SMALL("Video4Linux2 device grab"),
1036 .priv_data_size = sizeof(struct video_data),
1037 .read_header = v4l2_read_header,
1038 .read_packet = v4l2_read_packet,
1039 .read_close = v4l2_read_close,
1040 .flags = AVFMT_NOFILE,
1041 .priv_class = &v4l2_class,