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"
40 static const int desired_video_buffers = 256;
42 #define V4L_ALLFORMATS 3
43 #define V4L_RAWFORMATS 1
44 #define V4L_COMPFORMATS 2
47 * Return timestamps to the user exactly as returned by the kernel
49 #define V4L_TS_DEFAULT 0
51 * Autodetect the kind of timestamps returned by the kernel and convert to
52 * absolute (wall clock) timestamps.
56 * Assume kernel timestamps are from the monotonic clock and convert to
57 * absolute timestamps.
59 #define V4L_TS_MONO2ABS 2
62 * Once the kind of timestamps returned by the kernel have been detected,
63 * the value of the timefilter (NULL or not) determines whether a conversion
66 #define V4L_TS_CONVERT_READY V4L_TS_DEFAULT
71 int pixelformat; /* V4L2_PIX_FMT_* */
77 TimeFilter *timefilter;
81 volatile int buffers_queued;
83 unsigned int *buf_len;
87 char *pixel_format; /**< Set by a private option. */
88 int list_format; /**< Set by a private option. */
89 int list_standard; /**< Set by a private option. */
90 char *framerate; /**< Set by a private option. */
93 int (*open_f)(const char *file, int oflag, ...);
94 int (*close_f)(int fd);
96 int (*ioctl_f)(int fd, unsigned long int request, ...);
97 ssize_t (*read_f)(int fd, void *buffer, size_t n);
98 void *(*mmap_f)(void *start, size_t length, int prot, int flags, int fd, int64_t offset);
99 int (*munmap_f)(void *_start, size_t length);
103 struct video_data *s;
107 static int device_open(AVFormatContext *ctx)
109 struct video_data *s = ctx->priv_data;
110 struct v4l2_capability cap;
115 #define SET_WRAPPERS(prefix) do { \
116 s->open_f = prefix ## open; \
117 s->close_f = prefix ## close; \
118 s->dup_f = prefix ## dup; \
119 s->ioctl_f = prefix ## ioctl; \
120 s->read_f = prefix ## read; \
121 s->mmap_f = prefix ## mmap; \
122 s->munmap_f = prefix ## munmap; \
125 if (s->use_libv4l2) {
129 av_log(ctx, AV_LOG_ERROR, "libavdevice is not build with libv4l2 support.\n");
130 return AVERROR(EINVAL);
136 #define v4l2_open s->open_f
137 #define v4l2_close s->close_f
138 #define v4l2_dup s->dup_f
139 #define v4l2_ioctl s->ioctl_f
140 #define v4l2_read s->read_f
141 #define v4l2_mmap s->mmap_f
142 #define v4l2_munmap s->munmap_f
144 if (ctx->flags & AVFMT_FLAG_NONBLOCK) {
148 fd = v4l2_open(ctx->filename, flags, 0);
150 err = AVERROR(errno);
151 av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s: %s\n",
152 ctx->filename, av_err2str(err));
156 if (v4l2_ioctl(fd, VIDIOC_QUERYCAP, &cap) < 0) {
157 err = AVERROR(errno);
158 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
163 av_log(ctx, AV_LOG_VERBOSE, "fd:%d capabilities:%x\n",
164 fd, cap.capabilities);
166 if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {
167 av_log(ctx, AV_LOG_ERROR, "Not a video capture device.\n");
168 err = AVERROR(ENODEV);
172 if (!(cap.capabilities & V4L2_CAP_STREAMING)) {
173 av_log(ctx, AV_LOG_ERROR,
174 "The device does not support the streaming I/O method.\n");
175 err = AVERROR(ENOSYS);
186 static int device_init(AVFormatContext *ctx, int *width, int *height,
187 uint32_t pixelformat)
189 struct video_data *s = ctx->priv_data;
190 struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
193 fmt.fmt.pix.width = *width;
194 fmt.fmt.pix.height = *height;
195 fmt.fmt.pix.pixelformat = pixelformat;
196 fmt.fmt.pix.field = V4L2_FIELD_ANY;
198 /* Some drivers will fail and return EINVAL when the pixelformat
199 is not supported (even if type field is valid and supported) */
200 if (v4l2_ioctl(s->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 (pixelformat != 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 pixelformat, 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)
233 res = v4l2_ioctl(s->fd, VIDIOC_G_STD, &std);
236 if (std & V4L2_STD_NTSC)
242 #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
243 static void list_framesizes(AVFormatContext *ctx, uint32_t pixelformat)
245 const struct video_data *s = ctx->priv_data;
246 struct v4l2_frmsizeenum vfse = { .pixel_format = pixelformat };
248 while(!v4l2_ioctl(s->fd, VIDIOC_ENUM_FRAMESIZES, &vfse)) {
250 case V4L2_FRMSIZE_TYPE_DISCRETE:
251 av_log(ctx, AV_LOG_INFO, " %ux%u",
252 vfse.discrete.width, vfse.discrete.height);
254 case V4L2_FRMSIZE_TYPE_CONTINUOUS:
255 case V4L2_FRMSIZE_TYPE_STEPWISE:
256 av_log(ctx, AV_LOG_INFO, " {%u-%u, %u}x{%u-%u, %u}",
257 vfse.stepwise.min_width,
258 vfse.stepwise.max_width,
259 vfse.stepwise.step_width,
260 vfse.stepwise.min_height,
261 vfse.stepwise.max_height,
262 vfse.stepwise.step_height);
269 static void list_formats(AVFormatContext *ctx, int type)
271 const struct video_data *s = ctx->priv_data;
272 struct v4l2_fmtdesc vfd = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
274 while(!v4l2_ioctl(s->fd, VIDIOC_ENUM_FMT, &vfd)) {
275 enum AVCodecID codec_id = ff_fmt_v4l2codec(vfd.pixelformat);
276 enum AVPixelFormat pix_fmt = ff_fmt_v4l2ff(vfd.pixelformat, codec_id);
280 if (!(vfd.flags & V4L2_FMT_FLAG_COMPRESSED) &&
281 type & V4L_RAWFORMATS) {
282 const char *fmt_name = av_get_pix_fmt_name(pix_fmt);
283 av_log(ctx, AV_LOG_INFO, "Raw : %11s : %20s :",
284 fmt_name ? fmt_name : "Unsupported",
286 } else if (vfd.flags & V4L2_FMT_FLAG_COMPRESSED &&
287 type & V4L_COMPFORMATS) {
288 const AVCodecDescriptor *desc = avcodec_descriptor_get(codec_id);
289 av_log(ctx, AV_LOG_INFO, "Compressed: %11s : %20s :",
290 desc ? desc->name : "Unsupported",
296 #ifdef V4L2_FMT_FLAG_EMULATED
297 if (vfd.flags & V4L2_FMT_FLAG_EMULATED)
298 av_log(ctx, AV_LOG_INFO, " Emulated :");
300 #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
301 list_framesizes(ctx, vfd.pixelformat);
303 av_log(ctx, AV_LOG_INFO, "\n");
307 static void list_standards(AVFormatContext *ctx)
310 struct video_data *s = ctx->priv_data;
311 struct v4l2_standard standard;
316 for (standard.index = 0; ; standard.index++) {
317 if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
318 ret = AVERROR(errno);
319 if (ret == AVERROR(EINVAL)) {
322 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMSTD): %s\n", av_err2str(ret));
326 av_log(ctx, AV_LOG_INFO, "%2d, %16"PRIx64", %s\n",
327 standard.index, (uint64_t)standard.id, standard.name);
331 static int mmap_init(AVFormatContext *ctx)
334 struct video_data *s = ctx->priv_data;
335 struct v4l2_requestbuffers req = {
336 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
337 .count = desired_video_buffers,
338 .memory = V4L2_MEMORY_MMAP
341 if (v4l2_ioctl(s->fd, VIDIOC_REQBUFS, &req) < 0) {
342 res = AVERROR(errno);
343 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS): %s\n", av_err2str(res));
348 av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");
349 return AVERROR(ENOMEM);
351 s->buffers = req.count;
352 s->buf_start = av_malloc_array(s->buffers, sizeof(void *));
354 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
355 return AVERROR(ENOMEM);
357 s->buf_len = av_malloc_array(s->buffers, sizeof(unsigned int));
359 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
360 av_freep(&s->buf_start);
361 return AVERROR(ENOMEM);
364 for (i = 0; i < req.count; i++) {
365 struct v4l2_buffer buf = {
366 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
368 .memory = V4L2_MEMORY_MMAP
370 if (v4l2_ioctl(s->fd, VIDIOC_QUERYBUF, &buf) < 0) {
371 res = AVERROR(errno);
372 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF): %s\n", av_err2str(res));
376 s->buf_len[i] = buf.length;
377 if (s->frame_size > 0 && s->buf_len[i] < s->frame_size) {
378 av_log(ctx, AV_LOG_ERROR,
379 "buf_len[%d] = %d < expected frame size %d\n",
380 i, s->buf_len[i], s->frame_size);
381 return AVERROR(ENOMEM);
383 s->buf_start[i] = v4l2_mmap(NULL, buf.length,
384 PROT_READ | PROT_WRITE, MAP_SHARED,
385 s->fd, buf.m.offset);
387 if (s->buf_start[i] == MAP_FAILED) {
388 res = AVERROR(errno);
389 av_log(ctx, AV_LOG_ERROR, "mmap: %s\n", av_err2str(res));
397 #if FF_API_DESTRUCT_PACKET
398 static void dummy_release_buffer(AVPacket *pkt)
404 static int enqueue_buffer(struct video_data *s, struct v4l2_buffer *buf)
408 if (v4l2_ioctl(s->fd, VIDIOC_QBUF, buf) < 0) {
409 res = AVERROR(errno);
410 av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", av_err2str(res));
412 avpriv_atomic_int_add_and_fetch(&s->buffers_queued, 1);
418 static void mmap_release_buffer(void *opaque, uint8_t *data)
420 struct v4l2_buffer buf = { 0 };
421 struct buff_data *buf_descriptor = opaque;
422 struct video_data *s = buf_descriptor->s;
424 buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
425 buf.memory = V4L2_MEMORY_MMAP;
426 buf.index = buf_descriptor->index;
427 av_free(buf_descriptor);
429 enqueue_buffer(s, &buf);
432 #if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
433 static int64_t av_gettime_monotonic(void)
435 return av_gettime_relative();
439 static int init_convert_timestamp(AVFormatContext *ctx, int64_t ts)
441 struct video_data *s = ctx->priv_data;
445 if (s->ts_mode == V4L_TS_ABS &&
446 ts <= now + 1 * AV_TIME_BASE && ts >= now - 10 * AV_TIME_BASE) {
447 av_log(ctx, AV_LOG_INFO, "Detected absolute timestamps\n");
448 s->ts_mode = V4L_TS_CONVERT_READY;
451 #if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
452 if (ctx->streams[0]->avg_frame_rate.num) {
453 now = av_gettime_monotonic();
454 if (s->ts_mode == V4L_TS_MONO2ABS ||
455 (ts <= now + 1 * AV_TIME_BASE && ts >= now - 10 * AV_TIME_BASE)) {
456 AVRational tb = {AV_TIME_BASE, 1};
457 int64_t period = av_rescale_q(1, tb, ctx->streams[0]->avg_frame_rate);
458 av_log(ctx, AV_LOG_INFO, "Detected monotonic timestamps, converting\n");
459 /* microseconds instead of seconds, MHz instead of Hz */
460 s->timefilter = ff_timefilter_new(1, period, 1.0E-6);
462 return AVERROR(ENOMEM);
463 s->ts_mode = V4L_TS_CONVERT_READY;
468 av_log(ctx, AV_LOG_ERROR, "Unknown timestamps\n");
472 static int convert_timestamp(AVFormatContext *ctx, int64_t *ts)
474 struct video_data *s = ctx->priv_data;
477 int r = init_convert_timestamp(ctx, *ts);
481 #if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
483 int64_t nowa = av_gettime();
484 int64_t nowm = av_gettime_monotonic();
485 ff_timefilter_update(s->timefilter, nowa, nowm - s->last_time_m);
486 s->last_time_m = nowm;
487 *ts = ff_timefilter_eval(s->timefilter, *ts - nowm);
493 static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
495 struct video_data *s = ctx->priv_data;
496 struct v4l2_buffer buf = {
497 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
498 .memory = V4L2_MEMORY_MMAP
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 if (buf.index >= s->buffers) {
517 av_log(ctx, AV_LOG_ERROR, "Invalid buffer index received.\n");
518 return AVERROR(EINVAL);
520 avpriv_atomic_int_add_and_fetch(&s->buffers_queued, -1);
521 // always keep at least one buffer queued
522 av_assert0(avpriv_atomic_int_get(&s->buffers_queued) >= 1);
524 #ifdef V4L2_BUF_FLAG_ERROR
525 if (buf.flags & V4L2_BUF_FLAG_ERROR) {
526 av_log(ctx, AV_LOG_WARNING,
527 "Dequeued v4l2 buffer contains corrupted data (%d bytes).\n",
533 /* CPIA is a compressed format and we don't know the exact number of bytes
534 * used by a frame, so set it here as the driver announces it. */
535 if (ctx->video_codec_id == AV_CODEC_ID_CPIA)
536 s->frame_size = buf.bytesused;
538 if (s->frame_size > 0 && buf.bytesused != s->frame_size) {
539 av_log(ctx, AV_LOG_ERROR,
540 "Dequeued v4l2 buffer contains %d bytes, but %d were expected. Flags: 0x%08X.\n",
541 buf.bytesused, s->frame_size, buf.flags);
542 enqueue_buffer(s, &buf);
543 return AVERROR_INVALIDDATA;
547 /* Image is at s->buff_start[buf.index] */
548 if (avpriv_atomic_int_get(&s->buffers_queued) == FFMAX(s->buffers / 8, 1)) {
549 /* when we start getting low on queued buffers, fall back on copying data */
550 res = av_new_packet(pkt, buf.bytesused);
552 av_log(ctx, AV_LOG_ERROR, "Error allocating a packet.\n");
553 enqueue_buffer(s, &buf);
556 memcpy(pkt->data, s->buf_start[buf.index], buf.bytesused);
558 res = enqueue_buffer(s, &buf);
564 struct buff_data *buf_descriptor;
566 pkt->data = s->buf_start[buf.index];
567 pkt->size = buf.bytesused;
568 #if FF_API_DESTRUCT_PACKET
569 FF_DISABLE_DEPRECATION_WARNINGS
570 pkt->destruct = dummy_release_buffer;
571 FF_ENABLE_DEPRECATION_WARNINGS
574 buf_descriptor = av_malloc(sizeof(struct buff_data));
575 if (!buf_descriptor) {
576 /* Something went wrong... Since av_malloc() failed, we cannot even
577 * allocate a buffer for memcpying into it
579 av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
580 enqueue_buffer(s, &buf);
582 return AVERROR(ENOMEM);
584 buf_descriptor->index = buf.index;
585 buf_descriptor->s = s;
587 pkt->buf = av_buffer_create(pkt->data, pkt->size, mmap_release_buffer,
590 av_log(ctx, AV_LOG_ERROR, "Failed to create a buffer\n");
591 enqueue_buffer(s, &buf);
592 av_freep(&buf_descriptor);
593 return AVERROR(ENOMEM);
596 pkt->pts = buf.timestamp.tv_sec * INT64_C(1000000) + buf.timestamp.tv_usec;
597 convert_timestamp(ctx, &pkt->pts);
602 static int mmap_start(AVFormatContext *ctx)
604 struct video_data *s = ctx->priv_data;
605 enum v4l2_buf_type type;
608 for (i = 0; i < s->buffers; i++) {
609 struct v4l2_buffer buf = {
610 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
612 .memory = V4L2_MEMORY_MMAP
615 if (v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf) < 0) {
616 res = AVERROR(errno);
617 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n",
622 s->buffers_queued = s->buffers;
624 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
625 if (v4l2_ioctl(s->fd, VIDIOC_STREAMON, &type) < 0) {
626 res = AVERROR(errno);
627 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n",
635 static void mmap_close(struct video_data *s)
637 enum v4l2_buf_type type;
640 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
641 /* We do not check for the result, because we could
642 * not do anything about it anyway...
644 v4l2_ioctl(s->fd, VIDIOC_STREAMOFF, &type);
645 for (i = 0; i < s->buffers; i++) {
646 v4l2_munmap(s->buf_start[i], s->buf_len[i]);
648 av_freep(&s->buf_start);
649 av_freep(&s->buf_len);
652 static int v4l2_set_parameters(AVFormatContext *ctx)
654 struct video_data *s = ctx->priv_data;
655 struct v4l2_standard standard = { 0 };
656 struct v4l2_streamparm streamparm = { 0 };
657 struct v4l2_fract *tpf;
658 AVRational framerate_q = { 0 };
662 (ret = av_parse_video_rate(&framerate_q, s->framerate)) < 0) {
663 av_log(ctx, AV_LOG_ERROR, "Could not parse framerate '%s'.\n",
671 av_log(ctx, AV_LOG_DEBUG, "Setting standard: %s\n", s->standard);
672 /* set tv standard */
675 if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
676 ret = AVERROR(errno);
679 if (!av_strcasecmp(standard.name, s->standard))
683 av_log(ctx, AV_LOG_ERROR, "Unknown or unsupported standard '%s'\n", s->standard);
687 if (v4l2_ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
688 ret = AVERROR(errno);
689 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_S_STD): %s\n", av_err2str(ret));
693 av_log(ctx, AV_LOG_WARNING,
694 "This device does not support any standard\n");
699 if (v4l2_ioctl(s->fd, VIDIOC_G_STD, &s->std_id) == 0) {
700 tpf = &standard.frameperiod;
703 if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
704 ret = AVERROR(errno);
705 if (ret == AVERROR(EINVAL)
707 || ret == AVERROR(ENODATA)
710 tpf = &streamparm.parm.capture.timeperframe;
713 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMSTD): %s\n", av_err2str(ret));
716 if (standard.id == s->std_id) {
717 av_log(ctx, AV_LOG_DEBUG,
718 "Current standard: %s, id: %"PRIx64", frameperiod: %d/%d\n",
719 standard.name, (uint64_t)standard.id, tpf->numerator, tpf->denominator);
724 tpf = &streamparm.parm.capture.timeperframe;
727 streamparm.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
728 if (v4l2_ioctl(s->fd, VIDIOC_G_PARM, &streamparm) < 0) {
729 ret = AVERROR(errno);
730 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_G_PARM): %s\n", av_err2str(ret));
734 if (framerate_q.num && framerate_q.den) {
735 if (streamparm.parm.capture.capability & V4L2_CAP_TIMEPERFRAME) {
736 tpf = &streamparm.parm.capture.timeperframe;
738 av_log(ctx, AV_LOG_DEBUG, "Setting time per frame to %d/%d\n",
739 framerate_q.den, framerate_q.num);
740 tpf->numerator = framerate_q.den;
741 tpf->denominator = framerate_q.num;
743 if (v4l2_ioctl(s->fd, VIDIOC_S_PARM, &streamparm) < 0) {
744 ret = AVERROR(errno);
745 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_S_PARM): %s\n",
750 if (framerate_q.num != tpf->denominator ||
751 framerate_q.den != tpf->numerator) {
752 av_log(ctx, AV_LOG_INFO,
753 "The driver changed the time per frame from "
755 framerate_q.den, framerate_q.num,
756 tpf->numerator, tpf->denominator);
759 av_log(ctx, AV_LOG_WARNING,
760 "The driver does not permit changing the time per frame\n");
763 if (tpf->denominator > 0 && tpf->numerator > 0) {
764 ctx->streams[0]->avg_frame_rate.num = tpf->denominator;
765 ctx->streams[0]->avg_frame_rate.den = tpf->numerator;
766 ctx->streams[0]->r_frame_rate = ctx->streams[0]->avg_frame_rate;
768 av_log(ctx, AV_LOG_WARNING, "Time per frame unknown\n");
773 static int device_try_init(AVFormatContext *ctx,
774 enum AVPixelFormat pix_fmt,
777 uint32_t *desired_format,
778 enum AVCodecID *codec_id)
782 *desired_format = ff_fmt_ff2v4l(pix_fmt, ctx->video_codec_id);
784 if (*desired_format) {
785 ret = device_init(ctx, width, height, *desired_format);
788 if (ret != AVERROR(EINVAL))
793 if (!*desired_format) {
794 for (i = 0; ff_fmt_conversion_table[i].codec_id != AV_CODEC_ID_NONE; i++) {
795 if (ctx->video_codec_id == AV_CODEC_ID_NONE ||
796 ff_fmt_conversion_table[i].codec_id == ctx->video_codec_id) {
797 av_log(ctx, AV_LOG_DEBUG, "Trying to set codec:%s pix_fmt:%s\n",
798 avcodec_get_name(ff_fmt_conversion_table[i].codec_id),
799 (char *)av_x_if_null(av_get_pix_fmt_name(ff_fmt_conversion_table[i].ff_fmt), "none"));
801 *desired_format = ff_fmt_conversion_table[i].v4l2_fmt;
802 ret = device_init(ctx, width, height, *desired_format);
805 else if (ret != AVERROR(EINVAL))
811 if (*desired_format == 0) {
812 av_log(ctx, AV_LOG_ERROR, "Cannot find a proper format for "
813 "codec '%s' (id %d), pixel format '%s' (id %d)\n",
814 avcodec_get_name(ctx->video_codec_id), ctx->video_codec_id,
815 (char *)av_x_if_null(av_get_pix_fmt_name(pix_fmt), "none"), pix_fmt);
816 ret = AVERROR(EINVAL);
820 *codec_id = ff_fmt_v4l2codec(*desired_format);
821 av_assert0(*codec_id != AV_CODEC_ID_NONE);
825 static int v4l2_read_probe(AVProbeData *p)
827 if (av_strstart(p->filename, "/dev/video", NULL))
828 return AVPROBE_SCORE_MAX - 1;
832 static int v4l2_read_header(AVFormatContext *ctx)
834 struct video_data *s = ctx->priv_data;
837 uint32_t desired_format;
838 enum AVCodecID codec_id = AV_CODEC_ID_NONE;
839 enum AVPixelFormat pix_fmt = AV_PIX_FMT_NONE;
840 struct v4l2_input input = { 0 };
842 st = avformat_new_stream(ctx, NULL);
844 return AVERROR(ENOMEM);
847 /* silence libv4l2 logging. if fopen() fails v4l2_log_file will be NULL
848 and errors will get sent to stderr */
850 v4l2_log_file = fopen("/dev/null", "w");
853 s->fd = device_open(ctx);
857 if (s->channel != -1) {
858 /* set video input */
859 av_log(ctx, AV_LOG_DEBUG, "Selecting input_channel: %d\n", s->channel);
860 if (v4l2_ioctl(s->fd, VIDIOC_S_INPUT, &s->channel) < 0) {
861 res = AVERROR(errno);
862 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_S_INPUT): %s\n", av_err2str(res));
866 /* get current video input */
867 if (v4l2_ioctl(s->fd, VIDIOC_G_INPUT, &s->channel) < 0) {
868 res = AVERROR(errno);
869 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_G_INPUT): %s\n", av_err2str(res));
875 input.index = s->channel;
876 if (v4l2_ioctl(s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
877 res = AVERROR(errno);
878 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMINPUT): %s\n", av_err2str(res));
881 s->std_id = input.std;
882 av_log(ctx, AV_LOG_DEBUG, "Current input_channel: %d, input_name: %s, input_std: %"PRIx64"\n",
883 s->channel, input.name, (uint64_t)input.std);
885 if (s->list_format) {
886 list_formats(ctx, s->list_format);
891 if (s->list_standard) {
897 avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
899 if (s->pixel_format) {
900 AVCodec *codec = avcodec_find_decoder_by_name(s->pixel_format);
903 ctx->video_codec_id = codec->id;
905 pix_fmt = av_get_pix_fmt(s->pixel_format);
907 if (pix_fmt == AV_PIX_FMT_NONE && !codec) {
908 av_log(ctx, AV_LOG_ERROR, "No such input format: %s.\n",
911 res = AVERROR(EINVAL);
916 if (!s->width && !s->height) {
917 struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
919 av_log(ctx, AV_LOG_VERBOSE,
920 "Querying the device for the current frame size\n");
921 if (v4l2_ioctl(s->fd, VIDIOC_G_FMT, &fmt) < 0) {
922 res = AVERROR(errno);
923 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n",
928 s->width = fmt.fmt.pix.width;
929 s->height = fmt.fmt.pix.height;
930 av_log(ctx, AV_LOG_VERBOSE,
931 "Setting frame size to %dx%d\n", s->width, s->height);
934 res = device_try_init(ctx, pix_fmt, &s->width, &s->height, &desired_format, &codec_id);
938 /* If no pixel_format was specified, the codec_id was not known up
939 * until now. Set video_codec_id in the context, as codec_id will
940 * not be available outside this function
942 if (codec_id != AV_CODEC_ID_NONE && ctx->video_codec_id == AV_CODEC_ID_NONE)
943 ctx->video_codec_id = codec_id;
945 if ((res = av_image_check_size(s->width, s->height, 0, ctx)) < 0)
948 s->pixelformat = desired_format;
950 if ((res = v4l2_set_parameters(ctx)) < 0)
953 st->codec->pix_fmt = ff_fmt_v4l2ff(desired_format, codec_id);
955 avpicture_get_size(st->codec->pix_fmt, s->width, s->height);
957 if ((res = mmap_init(ctx)) ||
958 (res = mmap_start(ctx)) < 0)
961 s->top_field_first = first_field(s);
963 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
964 st->codec->codec_id = codec_id;
965 if (codec_id == AV_CODEC_ID_RAWVIDEO)
966 st->codec->codec_tag =
967 avcodec_pix_fmt_to_codec_tag(st->codec->pix_fmt);
968 else if (codec_id == AV_CODEC_ID_H264) {
969 st->need_parsing = AVSTREAM_PARSE_HEADERS;
971 if (desired_format == V4L2_PIX_FMT_YVU420)
972 st->codec->codec_tag = MKTAG('Y', 'V', '1', '2');
973 else if (desired_format == V4L2_PIX_FMT_YVU410)
974 st->codec->codec_tag = MKTAG('Y', 'V', 'U', '9');
975 st->codec->width = s->width;
976 st->codec->height = s->height;
977 if (st->avg_frame_rate.den)
978 st->codec->bit_rate = s->frame_size * av_q2d(st->avg_frame_rate) * 8;
987 static int v4l2_read_packet(AVFormatContext *ctx, AVPacket *pkt)
989 struct video_data *s = ctx->priv_data;
990 AVFrame *frame = ctx->streams[0]->codec->coded_frame;
994 if ((res = mmap_read_frame(ctx, pkt)) < 0) {
998 if (frame && s->interlaced) {
999 frame->interlaced_frame = 1;
1000 frame->top_field_first = s->top_field_first;
1006 static int v4l2_read_close(AVFormatContext *ctx)
1008 struct video_data *s = ctx->priv_data;
1010 if (avpriv_atomic_int_get(&s->buffers_queued) != s->buffers)
1011 av_log(ctx, AV_LOG_WARNING, "Some buffers are still owned by the caller on "
1020 static int v4l2_is_v4l_dev(const char *name)
1022 return !strncmp(name, "video", 5) ||
1023 !strncmp(name, "radio", 5) ||
1024 !strncmp(name, "vbi", 3) ||
1025 !strncmp(name, "v4l-subdev", 10);
1028 static int v4l2_get_device_list(AVFormatContext *ctx, AVDeviceInfoList *device_list)
1030 struct video_data *s = ctx->priv_data;
1032 struct dirent *entry;
1033 AVDeviceInfo *device = NULL;
1034 struct v4l2_capability cap;
1038 return AVERROR(EINVAL);
1040 dir = opendir("/dev");
1042 ret = AVERROR(errno);
1043 av_log(ctx, AV_LOG_ERROR, "Couldn't open the directory: %s\n", av_err2str(ret));
1046 while ((entry = readdir(dir))) {
1047 if (!v4l2_is_v4l_dev(entry->d_name))
1050 snprintf(ctx->filename, sizeof(ctx->filename), "/dev/%s", entry->d_name);
1051 if ((s->fd = device_open(ctx)) < 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(ctx->filename);
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_INT, {.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,