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(sizeof(void *) * s->buffers);
355 if (s->buf_start == NULL) {
356 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
357 return AVERROR(ENOMEM);
359 s->buf_len = av_malloc(sizeof(unsigned int) * s->buffers);
360 if (s->buf_len == NULL) {
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)
432 clock_gettime(CLOCK_MONOTONIC, &tv);
433 return (int64_t)tv.tv_sec * 1000000 + tv.tv_nsec / 1000;
437 static int init_convert_timestamp(AVFormatContext *ctx, int64_t ts)
439 struct video_data *s = ctx->priv_data;
443 if (s->ts_mode == V4L_TS_ABS &&
444 ts <= now + 1 * AV_TIME_BASE && ts >= now - 10 * AV_TIME_BASE) {
445 av_log(ctx, AV_LOG_INFO, "Detected absolute timestamps\n");
446 s->ts_mode = V4L_TS_CONVERT_READY;
449 #if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
450 if (ctx->streams[0]->avg_frame_rate.num) {
451 now = av_gettime_monotonic();
452 if (s->ts_mode == V4L_TS_MONO2ABS ||
453 (ts <= now + 1 * AV_TIME_BASE && ts >= now - 10 * AV_TIME_BASE)) {
454 AVRational tb = {AV_TIME_BASE, 1};
455 int64_t period = av_rescale_q(1, tb, ctx->streams[0]->avg_frame_rate);
456 av_log(ctx, AV_LOG_INFO, "Detected monotonic timestamps, converting\n");
457 /* microseconds instead of seconds, MHz instead of Hz */
458 s->timefilter = ff_timefilter_new(1, period, 1.0E-6);
460 return AVERROR(ENOMEM);
461 s->ts_mode = V4L_TS_CONVERT_READY;
466 av_log(ctx, AV_LOG_ERROR, "Unknown timestamps\n");
470 static int convert_timestamp(AVFormatContext *ctx, int64_t *ts)
472 struct video_data *s = ctx->priv_data;
475 int r = init_convert_timestamp(ctx, *ts);
479 #if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
481 int64_t nowa = av_gettime();
482 int64_t nowm = av_gettime_monotonic();
483 ff_timefilter_update(s->timefilter, nowa, nowm - s->last_time_m);
484 s->last_time_m = nowm;
485 *ts = ff_timefilter_eval(s->timefilter, *ts - nowm);
491 static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
493 struct video_data *s = ctx->priv_data;
494 struct v4l2_buffer buf = {
495 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
496 .memory = V4L2_MEMORY_MMAP
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));
503 if (errno == EAGAIN) {
505 return AVERROR(EAGAIN);
507 res = AVERROR(errno);
508 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n", av_err2str(res));
512 if (buf.index >= s->buffers) {
513 av_log(ctx, AV_LOG_ERROR, "Invalid buffer index received.\n");
514 return AVERROR(EINVAL);
516 avpriv_atomic_int_add_and_fetch(&s->buffers_queued, -1);
517 // always keep at least one buffer queued
518 av_assert0(avpriv_atomic_int_get(&s->buffers_queued) >= 1);
520 /* CPIA is a compressed format and we don't know the exact number of bytes
521 * used by a frame, so set it here as the driver announces it.
523 if (ctx->video_codec_id == AV_CODEC_ID_CPIA)
524 s->frame_size = buf.bytesused;
526 if (s->frame_size > 0 && buf.bytesused != s->frame_size) {
527 av_log(ctx, AV_LOG_ERROR,
528 "The v4l2 frame is %d bytes, but %d bytes are expected\n",
529 buf.bytesused, s->frame_size);
530 return AVERROR_INVALIDDATA;
533 /* Image is at s->buff_start[buf.index] */
534 if (avpriv_atomic_int_get(&s->buffers_queued) == FFMAX(s->buffers / 8, 1)) {
535 /* when we start getting low on queued buffers, fall back on copying data */
536 res = av_new_packet(pkt, buf.bytesused);
538 av_log(ctx, AV_LOG_ERROR, "Error allocating a packet.\n");
539 if (v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf) == 0)
540 avpriv_atomic_int_add_and_fetch(&s->buffers_queued, 1);
543 memcpy(pkt->data, s->buf_start[buf.index], buf.bytesused);
545 if (v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf) < 0) {
546 res = AVERROR(errno);
547 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", av_err2str(res));
551 avpriv_atomic_int_add_and_fetch(&s->buffers_queued, 1);
553 struct buff_data *buf_descriptor;
555 pkt->data = s->buf_start[buf.index];
556 pkt->size = buf.bytesused;
557 #if FF_API_DESTRUCT_PACKET
558 FF_DISABLE_DEPRECATION_WARNINGS
559 pkt->destruct = dummy_release_buffer;
560 FF_ENABLE_DEPRECATION_WARNINGS
563 buf_descriptor = av_malloc(sizeof(struct buff_data));
564 if (buf_descriptor == NULL) {
565 /* Something went wrong... Since av_malloc() failed, we cannot even
566 * allocate a buffer for memcpying into it
568 av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
569 if (v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf) == 0)
570 avpriv_atomic_int_add_and_fetch(&s->buffers_queued, 1);
572 return AVERROR(ENOMEM);
574 buf_descriptor->index = buf.index;
575 buf_descriptor->s = s;
577 pkt->buf = av_buffer_create(pkt->data, pkt->size, mmap_release_buffer,
580 av_log(ctx, AV_LOG_ERROR, "Failed to create a buffer\n");
581 if (v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf) == 0)
582 avpriv_atomic_int_add_and_fetch(&s->buffers_queued, 1);
583 av_freep(&buf_descriptor);
584 return AVERROR(ENOMEM);
587 pkt->pts = buf.timestamp.tv_sec * INT64_C(1000000) + buf.timestamp.tv_usec;
588 convert_timestamp(ctx, &pkt->pts);
590 return s->buf_len[buf.index];
593 static int mmap_start(AVFormatContext *ctx)
595 struct video_data *s = ctx->priv_data;
596 enum v4l2_buf_type type;
599 for (i = 0; i < s->buffers; i++) {
600 struct v4l2_buffer buf = {
601 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
603 .memory = V4L2_MEMORY_MMAP
606 if (v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf) < 0) {
607 res = AVERROR(errno);
608 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", av_err2str(res));
612 s->buffers_queued = s->buffers;
614 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
615 if (v4l2_ioctl(s->fd, VIDIOC_STREAMON, &type) < 0) {
616 res = AVERROR(errno);
617 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n", av_err2str(res));
624 static void mmap_close(struct video_data *s)
626 enum v4l2_buf_type type;
629 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
630 /* We do not check for the result, because we could
631 * not do anything about it anyway...
633 v4l2_ioctl(s->fd, VIDIOC_STREAMOFF, &type);
634 for (i = 0; i < s->buffers; i++) {
635 v4l2_munmap(s->buf_start[i], s->buf_len[i]);
637 av_free(s->buf_start);
641 static int v4l2_set_parameters(AVFormatContext *s1)
643 struct video_data *s = s1->priv_data;
644 struct v4l2_standard standard = { 0 };
645 struct v4l2_streamparm streamparm = { 0 };
646 struct v4l2_fract *tpf;
647 AVRational framerate_q = { 0 };
651 (ret = av_parse_video_rate(&framerate_q, s->framerate)) < 0) {
652 av_log(s1, AV_LOG_ERROR, "Could not parse framerate '%s'.\n",
660 av_log(s1, AV_LOG_DEBUG, "Setting standard: %s\n", s->standard);
661 /* set tv standard */
664 if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
665 ret = AVERROR(errno);
668 if (!av_strcasecmp(standard.name, s->standard))
672 av_log(s1, AV_LOG_ERROR, "Unknown or unsupported standard '%s'\n", s->standard);
676 if (v4l2_ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
677 ret = AVERROR(errno);
678 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_S_STD): %s\n", av_err2str(ret));
682 av_log(s1, AV_LOG_WARNING,
683 "This device does not support any standard\n");
688 if (v4l2_ioctl(s->fd, VIDIOC_G_STD, &s->std_id) == 0) {
689 tpf = &standard.frameperiod;
692 if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
693 ret = AVERROR(errno);
694 if (ret == AVERROR(EINVAL)) {
695 tpf = &streamparm.parm.capture.timeperframe;
698 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMSTD): %s\n", av_err2str(ret));
701 if (standard.id == s->std_id) {
702 av_log(s1, AV_LOG_DEBUG,
703 "Current standard: %s, id: %"PRIx64", frameperiod: %d/%d\n",
704 standard.name, (uint64_t)standard.id, tpf->numerator, tpf->denominator);
709 tpf = &streamparm.parm.capture.timeperframe;
712 streamparm.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
713 if (v4l2_ioctl(s->fd, VIDIOC_G_PARM, &streamparm) < 0) {
714 ret = AVERROR(errno);
715 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_PARM): %s\n", av_err2str(ret));
719 if (framerate_q.num && framerate_q.den) {
720 if (streamparm.parm.capture.capability & V4L2_CAP_TIMEPERFRAME) {
721 tpf = &streamparm.parm.capture.timeperframe;
723 av_log(s1, AV_LOG_DEBUG, "Setting time per frame to %d/%d\n",
724 framerate_q.den, framerate_q.num);
725 tpf->numerator = framerate_q.den;
726 tpf->denominator = framerate_q.num;
728 if (v4l2_ioctl(s->fd, VIDIOC_S_PARM, &streamparm) < 0) {
729 ret = AVERROR(errno);
730 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_S_PARM): %s\n", av_err2str(ret));
734 if (framerate_q.num != tpf->denominator ||
735 framerate_q.den != tpf->numerator) {
736 av_log(s1, AV_LOG_INFO,
737 "The driver changed the time per frame from "
739 framerate_q.den, framerate_q.num,
740 tpf->numerator, tpf->denominator);
743 av_log(s1, AV_LOG_WARNING,
744 "The driver does not allow to change time per frame\n");
747 if (tpf->denominator > 0 && tpf->numerator > 0) {
748 s1->streams[0]->avg_frame_rate.num = tpf->denominator;
749 s1->streams[0]->avg_frame_rate.den = tpf->numerator;
750 s1->streams[0]->r_frame_rate = s1->streams[0]->avg_frame_rate;
752 av_log(s1, AV_LOG_WARNING, "Time per frame unknown\n");
757 static int device_try_init(AVFormatContext *s1,
758 enum AVPixelFormat pix_fmt,
761 uint32_t *desired_format,
762 enum AVCodecID *codec_id)
766 *desired_format = avpriv_fmt_ff2v4l(pix_fmt, s1->video_codec_id);
768 if (*desired_format) {
769 ret = device_init(s1, width, height, *desired_format);
772 if (ret != AVERROR(EINVAL))
777 if (!*desired_format) {
778 for (i = 0; avpriv_fmt_conversion_table[i].codec_id != AV_CODEC_ID_NONE; i++) {
779 if (s1->video_codec_id == AV_CODEC_ID_NONE ||
780 avpriv_fmt_conversion_table[i].codec_id == s1->video_codec_id) {
781 av_log(s1, AV_LOG_DEBUG, "Trying to set codec:%s pix_fmt:%s\n",
782 avcodec_get_name(avpriv_fmt_conversion_table[i].codec_id),
783 (char *)av_x_if_null(av_get_pix_fmt_name(avpriv_fmt_conversion_table[i].ff_fmt), "none"));
785 *desired_format = avpriv_fmt_conversion_table[i].v4l2_fmt;
786 ret = device_init(s1, width, height, *desired_format);
789 else if (ret != AVERROR(EINVAL))
795 if (*desired_format == 0) {
796 av_log(s1, AV_LOG_ERROR, "Cannot find a proper format for "
797 "codec '%s' (id %d), pixel format '%s' (id %d)\n",
798 avcodec_get_name(s1->video_codec_id), s1->video_codec_id,
799 (char *)av_x_if_null(av_get_pix_fmt_name(pix_fmt), "none"), pix_fmt);
800 ret = AVERROR(EINVAL);
804 *codec_id = avpriv_fmt_v4l2codec(*desired_format);
805 av_assert0(*codec_id != AV_CODEC_ID_NONE);
809 static int v4l2_read_header(AVFormatContext *s1)
811 struct video_data *s = s1->priv_data;
814 uint32_t desired_format;
815 enum AVCodecID codec_id = AV_CODEC_ID_NONE;
816 enum AVPixelFormat pix_fmt = AV_PIX_FMT_NONE;
817 struct v4l2_input input = { 0 };
819 st = avformat_new_stream(s1, NULL);
821 return AVERROR(ENOMEM);
824 /* silence libv4l2 logging. if fopen() fails v4l2_log_file will be NULL
825 and errors will get sent to stderr */
827 v4l2_log_file = fopen("/dev/null", "w");
830 s->fd = device_open(s1);
834 if (s->channel != -1) {
835 /* set video input */
836 av_log(s1, AV_LOG_DEBUG, "Selecting input_channel: %d\n", s->channel);
837 if (v4l2_ioctl(s->fd, VIDIOC_S_INPUT, &s->channel) < 0) {
838 res = AVERROR(errno);
839 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_S_INPUT): %s\n", av_err2str(res));
843 /* get current video input */
844 if (v4l2_ioctl(s->fd, VIDIOC_G_INPUT, &s->channel) < 0) {
845 res = AVERROR(errno);
846 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_INPUT): %s\n", av_err2str(res));
852 input.index = s->channel;
853 if (v4l2_ioctl(s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
854 res = AVERROR(errno);
855 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMINPUT): %s\n", av_err2str(res));
858 s->std_id = input.std;
859 av_log(s1, AV_LOG_DEBUG, "Current input_channel: %d, input_name: %s, input_std: %"PRIx64"\n",
860 s->channel, input.name, (uint64_t)input.std);
862 if (s->list_format) {
863 list_formats(s1, s->fd, s->list_format);
867 if (s->list_standard) {
872 avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
874 if ((res = v4l2_set_parameters(s1)) < 0)
877 if (s->pixel_format) {
878 AVCodec *codec = avcodec_find_decoder_by_name(s->pixel_format);
881 s1->video_codec_id = codec->id;
883 pix_fmt = av_get_pix_fmt(s->pixel_format);
885 if (pix_fmt == AV_PIX_FMT_NONE && !codec) {
886 av_log(s1, AV_LOG_ERROR, "No such input format: %s.\n",
889 return AVERROR(EINVAL);
893 if (!s->width && !s->height) {
894 struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
896 av_log(s1, AV_LOG_VERBOSE,
897 "Querying the device for the current frame size\n");
898 if (v4l2_ioctl(s->fd, VIDIOC_G_FMT, &fmt) < 0) {
899 res = AVERROR(errno);
900 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n", av_err2str(res));
904 s->width = fmt.fmt.pix.width;
905 s->height = fmt.fmt.pix.height;
906 av_log(s1, AV_LOG_VERBOSE,
907 "Setting frame size to %dx%d\n", s->width, s->height);
910 res = device_try_init(s1, pix_fmt, &s->width, &s->height, &desired_format, &codec_id);
916 /* If no pixel_format was specified, the codec_id was not known up
917 * until now. Set video_codec_id in the context, as codec_id will
918 * not be available outside this function
920 if (codec_id != AV_CODEC_ID_NONE && s1->video_codec_id == AV_CODEC_ID_NONE)
921 s1->video_codec_id = codec_id;
923 if ((res = av_image_check_size(s->width, s->height, 0, s1)) < 0)
926 s->frame_format = desired_format;
928 st->codec->pix_fmt = avpriv_fmt_v4l2ff(desired_format, codec_id);
930 avpicture_get_size(st->codec->pix_fmt, s->width, s->height);
932 if ((res = mmap_init(s1)) ||
933 (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;
960 static int v4l2_read_packet(AVFormatContext *s1, AVPacket *pkt)
962 struct video_data *s = s1->priv_data;
963 AVFrame *frame = s1->streams[0]->codec->coded_frame;
967 if ((res = mmap_read_frame(s1, pkt)) < 0) {
971 if (frame && s->interlaced) {
972 frame->interlaced_frame = 1;
973 frame->top_field_first = s->top_field_first;
979 static int v4l2_read_close(AVFormatContext *s1)
981 struct video_data *s = s1->priv_data;
983 if (avpriv_atomic_int_get(&s->buffers_queued) != s->buffers)
984 av_log(s1, AV_LOG_WARNING, "Some buffers are still owned by the caller on "
993 #define OFFSET(x) offsetof(struct video_data, x)
994 #define DEC AV_OPT_FLAG_DECODING_PARAM
996 static const AVOption options[] = {
997 { "standard", "set TV standard, used only by analog frame grabber", OFFSET(standard), AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, DEC },
998 { "channel", "set TV channel, used only by frame grabber", OFFSET(channel), AV_OPT_TYPE_INT, {.i64 = -1 }, -1, INT_MAX, DEC },
999 { "video_size", "set frame size", OFFSET(width), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, DEC },
1000 { "pixel_format", "set preferred pixel format", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
1001 { "input_format", "set preferred pixel format (for raw video) or codec name", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
1002 { "framerate", "set frame rate", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
1004 { "list_formats", "list available formats and exit", OFFSET(list_format), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, DEC, "list_formats" },
1005 { "all", "show all available formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_ALLFORMATS }, 0, INT_MAX, DEC, "list_formats" },
1006 { "raw", "show only non-compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_RAWFORMATS }, 0, INT_MAX, DEC, "list_formats" },
1007 { "compressed", "show only compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_COMPFORMATS }, 0, INT_MAX, DEC, "list_formats" },
1009 { "list_standards", "list supported standards and exit", OFFSET(list_standard), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 1, DEC, "list_standards" },
1010 { "all", "show all supported standards", OFFSET(list_standard), AV_OPT_TYPE_CONST, {.i64 = 1 }, 0, 0, DEC, "list_standards" },
1012 { "timestamps", "set type of timestamps for grabbed frames", OFFSET(ts_mode), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 2, DEC, "timestamps" },
1013 { "ts", "set type of timestamps for grabbed frames", OFFSET(ts_mode), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 2, DEC, "timestamps" },
1014 { "default", "use timestamps from the kernel", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.i64 = V4L_TS_DEFAULT }, 0, 2, DEC, "timestamps" },
1015 { "abs", "use absolute timestamps (wall clock)", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.i64 = V4L_TS_ABS }, 0, 2, DEC, "timestamps" },
1016 { "mono2abs", "force conversion from monotonic to absolute timestamps", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.i64 = V4L_TS_MONO2ABS }, 0, 2, DEC, "timestamps" },
1017 { "use_libv4l2", "use libv4l2 (v4l-utils) convertion functions", OFFSET(use_libv4l2), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, DEC },
1021 static const AVClass v4l2_class = {
1022 .class_name = "V4L2 indev",
1023 .item_name = av_default_item_name,
1025 .version = LIBAVUTIL_VERSION_INT,
1026 .category = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
1029 AVInputFormat ff_v4l2_demuxer = {
1030 .name = "video4linux2,v4l2",
1031 .long_name = NULL_IF_CONFIG_SMALL("Video4Linux2 device grab"),
1032 .priv_data_size = sizeof(struct video_data),
1033 .read_header = v4l2_read_header,
1034 .read_packet = v4l2_read_packet,
1035 .read_close = v4l2_read_close,
1036 .flags = AVFMT_NOFILE,
1037 .priv_class = &v4l2_class,