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;
189 struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
190 struct v4l2_pix_format *pix = &fmt.fmt.pix;
194 pix->height = *height;
195 pix->pixelformat = pix_fmt;
196 pix->field = V4L2_FIELD_ANY;
198 if (v4l2_ioctl(s->fd, VIDIOC_S_FMT, &fmt) < 0)
199 res = AVERROR(errno);
201 if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {
202 av_log(ctx, AV_LOG_INFO,
203 "The V4L2 driver changed the video from %dx%d to %dx%d\n",
204 *width, *height, fmt.fmt.pix.width, fmt.fmt.pix.height);
205 *width = fmt.fmt.pix.width;
206 *height = fmt.fmt.pix.height;
209 if (pix_fmt != fmt.fmt.pix.pixelformat) {
210 av_log(ctx, AV_LOG_DEBUG,
211 "The V4L2 driver changed the pixel format "
212 "from 0x%08X to 0x%08X\n",
213 pix_fmt, fmt.fmt.pix.pixelformat);
214 res = AVERROR(EINVAL);
217 if (fmt.fmt.pix.field == V4L2_FIELD_INTERLACED) {
218 av_log(ctx, AV_LOG_DEBUG,
219 "The V4L2 driver is using the interlaced mode\n");
226 static int first_field(const struct video_data *s)
231 res = v4l2_ioctl(s->fd, VIDIOC_G_STD, &std);
234 if (std & V4L2_STD_NTSC)
240 #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
241 static void list_framesizes(AVFormatContext *ctx, uint32_t pixelformat)
243 const struct video_data *s = ctx->priv_data;
244 struct v4l2_frmsizeenum vfse = { .pixel_format = pixelformat };
246 while(!v4l2_ioctl(s->fd, VIDIOC_ENUM_FRAMESIZES, &vfse)) {
248 case V4L2_FRMSIZE_TYPE_DISCRETE:
249 av_log(ctx, AV_LOG_INFO, " %ux%u",
250 vfse.discrete.width, vfse.discrete.height);
252 case V4L2_FRMSIZE_TYPE_CONTINUOUS:
253 case V4L2_FRMSIZE_TYPE_STEPWISE:
254 av_log(ctx, AV_LOG_INFO, " {%u-%u, %u}x{%u-%u, %u}",
255 vfse.stepwise.min_width,
256 vfse.stepwise.max_width,
257 vfse.stepwise.step_width,
258 vfse.stepwise.min_height,
259 vfse.stepwise.max_height,
260 vfse.stepwise.step_height);
267 static void list_formats(AVFormatContext *ctx, int type)
269 const struct video_data *s = ctx->priv_data;
270 struct v4l2_fmtdesc vfd = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
272 while(!v4l2_ioctl(s->fd, VIDIOC_ENUM_FMT, &vfd)) {
273 enum AVCodecID codec_id = avpriv_fmt_v4l2codec(vfd.pixelformat);
274 enum AVPixelFormat pix_fmt = avpriv_fmt_v4l2ff(vfd.pixelformat, codec_id);
278 if (!(vfd.flags & V4L2_FMT_FLAG_COMPRESSED) &&
279 type & V4L_RAWFORMATS) {
280 const char *fmt_name = av_get_pix_fmt_name(pix_fmt);
281 av_log(ctx, AV_LOG_INFO, "Raw : %9s : %20s :",
282 fmt_name ? fmt_name : "Unsupported",
284 } else if (vfd.flags & V4L2_FMT_FLAG_COMPRESSED &&
285 type & V4L_COMPFORMATS) {
286 AVCodec *codec = avcodec_find_decoder(codec_id);
287 av_log(ctx, AV_LOG_INFO, "Compressed: %9s : %20s :",
288 codec ? codec->name : "Unsupported",
294 #ifdef V4L2_FMT_FLAG_EMULATED
295 if (vfd.flags & V4L2_FMT_FLAG_EMULATED)
296 av_log(ctx, AV_LOG_INFO, " Emulated :");
298 #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
299 list_framesizes(ctx, vfd.pixelformat);
301 av_log(ctx, AV_LOG_INFO, "\n");
305 static void list_standards(AVFormatContext *ctx)
308 struct video_data *s = ctx->priv_data;
309 struct v4l2_standard standard;
314 for (standard.index = 0; ; standard.index++) {
315 if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
316 ret = AVERROR(errno);
317 if (ret == AVERROR(EINVAL)) {
320 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMSTD): %s\n", av_err2str(ret));
324 av_log(ctx, AV_LOG_INFO, "%2d, %16"PRIx64", %s\n",
325 standard.index, (uint64_t)standard.id, standard.name);
329 static int mmap_init(AVFormatContext *ctx)
332 struct video_data *s = ctx->priv_data;
333 struct v4l2_requestbuffers req = {
334 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
335 .count = desired_video_buffers,
336 .memory = V4L2_MEMORY_MMAP
339 if (v4l2_ioctl(s->fd, VIDIOC_REQBUFS, &req) < 0) {
340 res = AVERROR(errno);
341 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS): %s\n", av_err2str(res));
346 av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");
347 return AVERROR(ENOMEM);
349 s->buffers = req.count;
350 s->buf_start = av_malloc_array(s->buffers, sizeof(void *));
352 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
353 return AVERROR(ENOMEM);
355 s->buf_len = av_malloc_array(s->buffers, sizeof(unsigned int));
357 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
358 av_free(s->buf_start);
359 return AVERROR(ENOMEM);
362 for (i = 0; i < req.count; i++) {
363 struct v4l2_buffer buf = {
364 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
366 .memory = V4L2_MEMORY_MMAP
368 if (v4l2_ioctl(s->fd, VIDIOC_QUERYBUF, &buf) < 0) {
369 res = AVERROR(errno);
370 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF): %s\n", av_err2str(res));
374 s->buf_len[i] = buf.length;
375 if (s->frame_size > 0 && s->buf_len[i] < s->frame_size) {
376 av_log(ctx, AV_LOG_ERROR,
377 "buf_len[%d] = %d < expected frame size %d\n",
378 i, s->buf_len[i], s->frame_size);
379 return AVERROR(ENOMEM);
381 s->buf_start[i] = v4l2_mmap(NULL, buf.length,
382 PROT_READ | PROT_WRITE, MAP_SHARED,
383 s->fd, buf.m.offset);
385 if (s->buf_start[i] == MAP_FAILED) {
386 res = AVERROR(errno);
387 av_log(ctx, AV_LOG_ERROR, "mmap: %s\n", av_err2str(res));
395 #if FF_API_DESTRUCT_PACKET
396 static void dummy_release_buffer(AVPacket *pkt)
402 static int enqueue_buffer(struct video_data *s, struct v4l2_buffer *buf)
406 if (v4l2_ioctl(s->fd, VIDIOC_QBUF, buf) < 0) {
407 res = AVERROR(errno);
408 av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", av_err2str(res));
410 avpriv_atomic_int_add_and_fetch(&s->buffers_queued, 1);
416 static void mmap_release_buffer(void *opaque, uint8_t *data)
418 struct v4l2_buffer buf = { 0 };
419 struct buff_data *buf_descriptor = opaque;
420 struct video_data *s = buf_descriptor->s;
422 buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
423 buf.memory = V4L2_MEMORY_MMAP;
424 buf.index = buf_descriptor->index;
425 av_free(buf_descriptor);
427 enqueue_buffer(s, &buf);
430 #if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
431 static int64_t av_gettime_monotonic(void)
433 return av_gettime_relative();
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 enqueue_buffer(s, &buf);
531 return AVERROR_INVALIDDATA;
534 /* Image is at s->buff_start[buf.index] */
535 if (avpriv_atomic_int_get(&s->buffers_queued) == FFMAX(s->buffers / 8, 1)) {
536 /* when we start getting low on queued buffers, fall back on copying data */
537 res = av_new_packet(pkt, buf.bytesused);
539 av_log(ctx, AV_LOG_ERROR, "Error allocating a packet.\n");
540 enqueue_buffer(s, &buf);
543 memcpy(pkt->data, s->buf_start[buf.index], buf.bytesused);
545 res = enqueue_buffer(s, &buf);
551 struct buff_data *buf_descriptor;
553 pkt->data = s->buf_start[buf.index];
554 pkt->size = buf.bytesused;
555 #if FF_API_DESTRUCT_PACKET
556 FF_DISABLE_DEPRECATION_WARNINGS
557 pkt->destruct = dummy_release_buffer;
558 FF_ENABLE_DEPRECATION_WARNINGS
561 buf_descriptor = av_malloc(sizeof(struct buff_data));
562 if (!buf_descriptor) {
563 /* Something went wrong... Since av_malloc() failed, we cannot even
564 * allocate a buffer for memcpying into it
566 av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
567 enqueue_buffer(s, &buf);
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 enqueue_buffer(s, &buf);
579 av_freep(&buf_descriptor);
580 return AVERROR(ENOMEM);
583 pkt->pts = buf.timestamp.tv_sec * INT64_C(1000000) + buf.timestamp.tv_usec;
584 convert_timestamp(ctx, &pkt->pts);
586 return s->buf_len[buf.index];
589 static int mmap_start(AVFormatContext *ctx)
591 struct video_data *s = ctx->priv_data;
592 enum v4l2_buf_type type;
595 for (i = 0; i < s->buffers; i++) {
596 struct v4l2_buffer buf = {
597 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
599 .memory = V4L2_MEMORY_MMAP
602 if (v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf) < 0) {
603 res = AVERROR(errno);
604 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", av_err2str(res));
608 s->buffers_queued = s->buffers;
610 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
611 if (v4l2_ioctl(s->fd, VIDIOC_STREAMON, &type) < 0) {
612 res = AVERROR(errno);
613 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n", av_err2str(res));
620 static void mmap_close(struct video_data *s)
622 enum v4l2_buf_type type;
625 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
626 /* We do not check for the result, because we could
627 * not do anything about it anyway...
629 v4l2_ioctl(s->fd, VIDIOC_STREAMOFF, &type);
630 for (i = 0; i < s->buffers; i++) {
631 v4l2_munmap(s->buf_start[i], s->buf_len[i]);
633 av_free(s->buf_start);
637 static int v4l2_set_parameters(AVFormatContext *ctx)
639 struct video_data *s = ctx->priv_data;
640 struct v4l2_standard standard = { 0 };
641 struct v4l2_streamparm streamparm = { 0 };
642 struct v4l2_fract *tpf;
643 AVRational framerate_q = { 0 };
647 (ret = av_parse_video_rate(&framerate_q, s->framerate)) < 0) {
648 av_log(ctx, AV_LOG_ERROR, "Could not parse framerate '%s'.\n",
656 av_log(ctx, AV_LOG_DEBUG, "Setting standard: %s\n", s->standard);
657 /* set tv standard */
660 if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
661 ret = AVERROR(errno);
664 if (!av_strcasecmp(standard.name, s->standard))
668 av_log(ctx, AV_LOG_ERROR, "Unknown or unsupported standard '%s'\n", s->standard);
672 if (v4l2_ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
673 ret = AVERROR(errno);
674 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_S_STD): %s\n", av_err2str(ret));
678 av_log(ctx, AV_LOG_WARNING,
679 "This device does not support any standard\n");
684 if (v4l2_ioctl(s->fd, VIDIOC_G_STD, &s->std_id) == 0) {
685 tpf = &standard.frameperiod;
688 if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
689 ret = AVERROR(errno);
690 if (ret == AVERROR(EINVAL)
692 || ret == AVERROR(ENODATA)
695 tpf = &streamparm.parm.capture.timeperframe;
698 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMSTD): %s\n", av_err2str(ret));
701 if (standard.id == s->std_id) {
702 av_log(ctx, 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(ctx, 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(ctx, 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(ctx, 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(ctx, 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(ctx, AV_LOG_WARNING,
744 "The driver does not allow to change time per frame\n");
747 if (tpf->denominator > 0 && tpf->numerator > 0) {
748 ctx->streams[0]->avg_frame_rate.num = tpf->denominator;
749 ctx->streams[0]->avg_frame_rate.den = tpf->numerator;
750 ctx->streams[0]->r_frame_rate = ctx->streams[0]->avg_frame_rate;
752 av_log(ctx, AV_LOG_WARNING, "Time per frame unknown\n");
757 static int device_try_init(AVFormatContext *ctx,
758 enum AVPixelFormat pix_fmt,
761 uint32_t *desired_format,
762 enum AVCodecID *codec_id)
766 *desired_format = avpriv_fmt_ff2v4l(pix_fmt, ctx->video_codec_id);
768 if (*desired_format) {
769 ret = device_init(ctx, 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 (ctx->video_codec_id == AV_CODEC_ID_NONE ||
780 avpriv_fmt_conversion_table[i].codec_id == ctx->video_codec_id) {
781 av_log(ctx, 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(ctx, width, height, *desired_format);
789 else if (ret != AVERROR(EINVAL))
795 if (*desired_format == 0) {
796 av_log(ctx, AV_LOG_ERROR, "Cannot find a proper format for "
797 "codec '%s' (id %d), pixel format '%s' (id %d)\n",
798 avcodec_get_name(ctx->video_codec_id), ctx->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 *ctx)
811 struct video_data *s = ctx->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(ctx, 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(ctx);
834 if (s->channel != -1) {
835 /* set video input */
836 av_log(ctx, 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(ctx, 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(ctx, 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(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMINPUT): %s\n", av_err2str(res));
858 s->std_id = input.std;
859 av_log(ctx, 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(ctx, s->list_format);
868 if (s->list_standard) {
874 avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
876 if ((res = v4l2_set_parameters(ctx)) < 0)
879 if (s->pixel_format) {
880 AVCodec *codec = avcodec_find_decoder_by_name(s->pixel_format);
883 ctx->video_codec_id = codec->id;
885 pix_fmt = av_get_pix_fmt(s->pixel_format);
887 if (pix_fmt == AV_PIX_FMT_NONE && !codec) {
888 av_log(ctx, AV_LOG_ERROR, "No such input format: %s.\n",
891 res = AVERROR(EINVAL);
896 if (!s->width && !s->height) {
897 struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
899 av_log(ctx, AV_LOG_VERBOSE,
900 "Querying the device for the current frame size\n");
901 if (v4l2_ioctl(s->fd, VIDIOC_G_FMT, &fmt) < 0) {
902 res = AVERROR(errno);
903 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n", av_err2str(res));
907 s->width = fmt.fmt.pix.width;
908 s->height = fmt.fmt.pix.height;
909 av_log(ctx, AV_LOG_VERBOSE,
910 "Setting frame size to %dx%d\n", s->width, s->height);
913 res = device_try_init(ctx, pix_fmt, &s->width, &s->height, &desired_format, &codec_id);
917 /* If no pixel_format was specified, the codec_id was not known up
918 * until now. Set video_codec_id in the context, as codec_id will
919 * not be available outside this function
921 if (codec_id != AV_CODEC_ID_NONE && ctx->video_codec_id == AV_CODEC_ID_NONE)
922 ctx->video_codec_id = codec_id;
924 if ((res = av_image_check_size(s->width, s->height, 0, ctx)) < 0)
927 s->frame_format = desired_format;
929 st->codec->pix_fmt = avpriv_fmt_v4l2ff(desired_format, codec_id);
931 avpicture_get_size(st->codec->pix_fmt, s->width, s->height);
933 if ((res = mmap_init(ctx)) ||
934 (res = mmap_start(ctx)) < 0)
937 s->top_field_first = first_field(s);
939 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
940 st->codec->codec_id = codec_id;
941 if (codec_id == AV_CODEC_ID_RAWVIDEO)
942 st->codec->codec_tag =
943 avcodec_pix_fmt_to_codec_tag(st->codec->pix_fmt);
944 else if (codec_id == AV_CODEC_ID_H264) {
945 st->need_parsing = AVSTREAM_PARSE_HEADERS;
947 if (desired_format == V4L2_PIX_FMT_YVU420)
948 st->codec->codec_tag = MKTAG('Y', 'V', '1', '2');
949 else if (desired_format == V4L2_PIX_FMT_YVU410)
950 st->codec->codec_tag = MKTAG('Y', 'V', 'U', '9');
951 st->codec->width = s->width;
952 st->codec->height = s->height;
953 if (st->avg_frame_rate.den)
954 st->codec->bit_rate = s->frame_size * av_q2d(st->avg_frame_rate) * 8;
963 static int v4l2_read_packet(AVFormatContext *ctx, AVPacket *pkt)
965 struct video_data *s = ctx->priv_data;
966 AVFrame *frame = ctx->streams[0]->codec->coded_frame;
970 if ((res = mmap_read_frame(ctx, pkt)) < 0) {
974 if (frame && s->interlaced) {
975 frame->interlaced_frame = 1;
976 frame->top_field_first = s->top_field_first;
982 static int v4l2_read_close(AVFormatContext *ctx)
984 struct video_data *s = ctx->priv_data;
986 if (avpriv_atomic_int_get(&s->buffers_queued) != s->buffers)
987 av_log(ctx, AV_LOG_WARNING, "Some buffers are still owned by the caller on "
996 #define OFFSET(x) offsetof(struct video_data, x)
997 #define DEC AV_OPT_FLAG_DECODING_PARAM
999 static const AVOption options[] = {
1000 { "standard", "set TV standard, used only by analog frame grabber", OFFSET(standard), AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, DEC },
1001 { "channel", "set TV channel, used only by frame grabber", OFFSET(channel), AV_OPT_TYPE_INT, {.i64 = -1 }, -1, INT_MAX, DEC },
1002 { "video_size", "set frame size", OFFSET(width), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, DEC },
1003 { "pixel_format", "set preferred pixel format", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
1004 { "input_format", "set preferred pixel format (for raw video) or codec name", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
1005 { "framerate", "set frame rate", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
1007 { "list_formats", "list available formats and exit", OFFSET(list_format), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, DEC, "list_formats" },
1008 { "all", "show all available formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_ALLFORMATS }, 0, INT_MAX, DEC, "list_formats" },
1009 { "raw", "show only non-compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_RAWFORMATS }, 0, INT_MAX, DEC, "list_formats" },
1010 { "compressed", "show only compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_COMPFORMATS }, 0, INT_MAX, DEC, "list_formats" },
1012 { "list_standards", "list supported standards and exit", OFFSET(list_standard), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 1, DEC, "list_standards" },
1013 { "all", "show all supported standards", OFFSET(list_standard), AV_OPT_TYPE_CONST, {.i64 = 1 }, 0, 0, DEC, "list_standards" },
1015 { "timestamps", "set type of timestamps for grabbed frames", OFFSET(ts_mode), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 2, DEC, "timestamps" },
1016 { "ts", "set type of timestamps for grabbed frames", OFFSET(ts_mode), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 2, DEC, "timestamps" },
1017 { "default", "use timestamps from the kernel", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.i64 = V4L_TS_DEFAULT }, 0, 2, DEC, "timestamps" },
1018 { "abs", "use absolute timestamps (wall clock)", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.i64 = V4L_TS_ABS }, 0, 2, DEC, "timestamps" },
1019 { "mono2abs", "force conversion from monotonic to absolute timestamps", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.i64 = V4L_TS_MONO2ABS }, 0, 2, DEC, "timestamps" },
1020 { "use_libv4l2", "use libv4l2 (v4l-utils) conversion functions", OFFSET(use_libv4l2), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, DEC },
1024 static const AVClass v4l2_class = {
1025 .class_name = "V4L2 indev",
1026 .item_name = av_default_item_name,
1028 .version = LIBAVUTIL_VERSION_INT,
1029 .category = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
1032 AVInputFormat ff_v4l2_demuxer = {
1033 .name = "video4linux2,v4l2",
1034 .long_name = NULL_IF_CONFIG_SMALL("Video4Linux2 device grab"),
1035 .priv_data_size = sizeof(struct video_data),
1036 .read_header = v4l2_read_header,
1037 .read_packet = v4l2_read_packet,
1038 .read_close = v4l2_read_close,
1039 .flags = AVFMT_NOFILE,
1040 .priv_class = &v4l2_class,