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://v4l2spec.bytesex.org/v4l2spec/capture.c)
29 * Thanks to Michael Niedermayer for providing the mapping between
30 * V4L2_PIX_FMT_* and PIX_FMT_*
33 #undef __STRICT_ANSI__ //workaround due to broken kernel headers
35 #include "libavformat/internal.h"
38 #include <sys/ioctl.h>
41 #if HAVE_SYS_VIDEOIO_H
42 #include <sys/videoio.h>
45 #include <asm/types.h>
47 #include <linux/videodev2.h>
49 #include "libavutil/avassert.h"
50 #include "libavutil/imgutils.h"
51 #include "libavutil/log.h"
52 #include "libavutil/opt.h"
54 #include "timefilter.h"
55 #include "libavutil/parseutils.h"
56 #include "libavutil/pixdesc.h"
57 #include "libavutil/avstring.h"
62 #define v4l2_open open
63 #define v4l2_close close
65 #define v4l2_ioctl ioctl
66 #define v4l2_read read
67 #define v4l2_mmap mmap
68 #define v4l2_munmap munmap
71 static const int desired_video_buffers = 256;
73 #define V4L_ALLFORMATS 3
74 #define V4L_RAWFORMATS 1
75 #define V4L_COMPFORMATS 2
78 * Return timestamps to the user exactly as returned by the kernel
80 #define V4L_TS_DEFAULT 0
82 * Autodetect the kind of timestamps returned by the kernel and convert to
83 * absolute (wall clock) timestamps.
87 * Assume kernel timestamps are from the monotonic clock and convert to
88 * absolute timestamps.
90 #define V4L_TS_MONO2ABS 2
93 * Once the kind of timestamps returned by the kernel have been detected,
94 * the value of the timefilter (NULL or not) determines whether a conversion
97 #define V4L_TS_CONVERT_READY V4L_TS_DEFAULT
102 int frame_format; /* V4L2_PIX_FMT_* */
108 TimeFilter *timefilter;
113 unsigned int *buf_len;
116 char *pixel_format; /**< Set by a private option. */
117 int list_format; /**< Set by a private option. */
118 char *framerate; /**< Set by a private option. */
127 enum PixelFormat ff_fmt;
128 enum CodecID codec_id;
132 static struct fmt_map fmt_conversion_table[] = {
133 //ff_fmt codec_id v4l2_fmt
134 { PIX_FMT_YUV420P, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV420 },
135 { PIX_FMT_YUV420P, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YVU420 },
136 { PIX_FMT_YUV422P, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV422P },
137 { PIX_FMT_YUYV422, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUYV },
138 { PIX_FMT_UYVY422, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_UYVY },
139 { PIX_FMT_YUV411P, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV411P },
140 { PIX_FMT_YUV410P, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV410 },
141 { PIX_FMT_RGB555LE,CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB555 },
142 { PIX_FMT_RGB555BE,CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB555X },
143 { PIX_FMT_RGB565LE,CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB565 },
144 { PIX_FMT_RGB565BE,CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB565X },
145 { PIX_FMT_BGR24, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_BGR24 },
146 { PIX_FMT_RGB24, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB24 },
147 { PIX_FMT_BGR0, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_BGR32 },
148 { PIX_FMT_0RGB, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB32 },
149 { PIX_FMT_GRAY8, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_GREY },
150 { PIX_FMT_NV12, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_NV12 },
151 { PIX_FMT_NONE, CODEC_ID_MJPEG, V4L2_PIX_FMT_MJPEG },
152 { PIX_FMT_NONE, CODEC_ID_MJPEG, V4L2_PIX_FMT_JPEG },
155 static int device_open(AVFormatContext *ctx)
157 struct v4l2_capability cap;
162 if (ctx->flags & AVFMT_FLAG_NONBLOCK) {
166 fd = v4l2_open(ctx->filename, flags, 0);
170 av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s : %s\n",
171 ctx->filename, strerror(err));
176 res = v4l2_ioctl(fd, VIDIOC_QUERYCAP, &cap);
179 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
185 av_log(ctx, AV_LOG_VERBOSE, "[%d]Capabilities: %x\n",
186 fd, cap.capabilities);
188 if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {
189 av_log(ctx, AV_LOG_ERROR, "Not a video capture device.\n");
195 if (!(cap.capabilities & V4L2_CAP_STREAMING)) {
196 av_log(ctx, AV_LOG_ERROR,
197 "The device does not support the streaming I/O method.\n");
210 static int device_init(AVFormatContext *ctx, int *width, int *height,
213 struct video_data *s = ctx->priv_data;
215 struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
216 struct v4l2_pix_format *pix = &fmt.fmt.pix;
221 pix->height = *height;
222 pix->pixelformat = pix_fmt;
223 pix->field = V4L2_FIELD_ANY;
225 res = v4l2_ioctl(fd, VIDIOC_S_FMT, &fmt);
227 if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {
228 av_log(ctx, AV_LOG_INFO,
229 "The V4L2 driver changed the video from %dx%d to %dx%d\n",
230 *width, *height, fmt.fmt.pix.width, fmt.fmt.pix.height);
231 *width = fmt.fmt.pix.width;
232 *height = fmt.fmt.pix.height;
235 if (pix_fmt != fmt.fmt.pix.pixelformat) {
236 av_log(ctx, AV_LOG_DEBUG,
237 "The V4L2 driver changed the pixel format "
238 "from 0x%08X to 0x%08X\n",
239 pix_fmt, fmt.fmt.pix.pixelformat);
243 if (fmt.fmt.pix.field == V4L2_FIELD_INTERLACED) {
244 av_log(ctx, AV_LOG_DEBUG, "The V4L2 driver using the interlaced mode");
251 static int first_field(int fd)
256 res = v4l2_ioctl(fd, VIDIOC_G_STD, &std);
260 if (std & V4L2_STD_NTSC) {
267 static uint32_t fmt_ff2v4l(enum PixelFormat pix_fmt, enum CodecID codec_id)
271 for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
272 if ((codec_id == CODEC_ID_NONE ||
273 fmt_conversion_table[i].codec_id == codec_id) &&
274 (pix_fmt == PIX_FMT_NONE ||
275 fmt_conversion_table[i].ff_fmt == pix_fmt)) {
276 return fmt_conversion_table[i].v4l2_fmt;
283 static enum PixelFormat fmt_v4l2ff(uint32_t v4l2_fmt, enum CodecID codec_id)
287 for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
288 if (fmt_conversion_table[i].v4l2_fmt == v4l2_fmt &&
289 fmt_conversion_table[i].codec_id == codec_id) {
290 return fmt_conversion_table[i].ff_fmt;
297 static enum CodecID fmt_v4l2codec(uint32_t v4l2_fmt)
301 for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
302 if (fmt_conversion_table[i].v4l2_fmt == v4l2_fmt) {
303 return fmt_conversion_table[i].codec_id;
307 return CODEC_ID_NONE;
310 #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
311 static void list_framesizes(AVFormatContext *ctx, int fd, uint32_t pixelformat)
313 struct v4l2_frmsizeenum vfse = { .pixel_format = pixelformat };
315 while(!ioctl(fd, VIDIOC_ENUM_FRAMESIZES, &vfse)) {
317 case V4L2_FRMSIZE_TYPE_DISCRETE:
318 av_log(ctx, AV_LOG_INFO, " %ux%u",
319 vfse.discrete.width, vfse.discrete.height);
321 case V4L2_FRMSIZE_TYPE_CONTINUOUS:
322 case V4L2_FRMSIZE_TYPE_STEPWISE:
323 av_log(ctx, AV_LOG_INFO, " {%u-%u, %u}x{%u-%u, %u}",
324 vfse.stepwise.min_width,
325 vfse.stepwise.max_width,
326 vfse.stepwise.step_width,
327 vfse.stepwise.min_height,
328 vfse.stepwise.max_height,
329 vfse.stepwise.step_height);
336 static void list_formats(AVFormatContext *ctx, int fd, int type)
338 struct v4l2_fmtdesc vfd = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
340 while(!ioctl(fd, VIDIOC_ENUM_FMT, &vfd)) {
341 enum CodecID codec_id = fmt_v4l2codec(vfd.pixelformat);
342 enum PixelFormat pix_fmt = fmt_v4l2ff(vfd.pixelformat, codec_id);
346 if (!(vfd.flags & V4L2_FMT_FLAG_COMPRESSED) &&
347 type & V4L_RAWFORMATS) {
348 const char *fmt_name = av_get_pix_fmt_name(pix_fmt);
349 av_log(ctx, AV_LOG_INFO, "R : %9s : %20s :",
350 fmt_name ? fmt_name : "Unsupported",
352 } else if (vfd.flags & V4L2_FMT_FLAG_COMPRESSED &&
353 type & V4L_COMPFORMATS) {
354 AVCodec *codec = avcodec_find_encoder(codec_id);
355 av_log(ctx, AV_LOG_INFO, "C : %9s : %20s :",
356 codec ? codec->name : "Unsupported",
362 #ifdef V4L2_FMT_FLAG_EMULATED
363 if (vfd.flags & V4L2_FMT_FLAG_EMULATED) {
364 av_log(ctx, AV_LOG_WARNING, "%s", "Emulated");
368 #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
369 list_framesizes(ctx, fd, vfd.pixelformat);
371 av_log(ctx, AV_LOG_INFO, "\n");
375 static int mmap_init(AVFormatContext *ctx)
378 struct video_data *s = ctx->priv_data;
379 struct v4l2_requestbuffers req = {
380 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
381 .count = desired_video_buffers,
382 .memory = V4L2_MEMORY_MMAP
385 res = v4l2_ioctl(s->fd, VIDIOC_REQBUFS, &req);
387 if (errno == EINVAL) {
388 av_log(ctx, AV_LOG_ERROR, "Device does not support mmap\n");
390 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS)\n");
392 return AVERROR(errno);
396 av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");
397 return AVERROR(ENOMEM);
399 s->buffers = req.count;
400 s->buf_start = av_malloc(sizeof(void *) * s->buffers);
401 if (s->buf_start == NULL) {
402 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
403 return AVERROR(ENOMEM);
405 s->buf_len = av_malloc(sizeof(unsigned int) * s->buffers);
406 if (s->buf_len == NULL) {
407 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
408 av_free(s->buf_start);
409 return AVERROR(ENOMEM);
412 for (i = 0; i < req.count; i++) {
413 struct v4l2_buffer buf = {
414 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
416 .memory = V4L2_MEMORY_MMAP
418 res = v4l2_ioctl(s->fd, VIDIOC_QUERYBUF, &buf);
420 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF)\n");
421 return AVERROR(errno);
424 s->buf_len[i] = buf.length;
425 if (s->frame_size > 0 && s->buf_len[i] < s->frame_size) {
426 av_log(ctx, AV_LOG_ERROR,
427 "Buffer len [%d] = %d != %d\n",
428 i, s->buf_len[i], s->frame_size);
432 s->buf_start[i] = v4l2_mmap(NULL, buf.length,
433 PROT_READ | PROT_WRITE, MAP_SHARED,
434 s->fd, buf.m.offset);
436 if (s->buf_start[i] == MAP_FAILED) {
437 av_log(ctx, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
438 return AVERROR(errno);
445 static void mmap_release_buffer(AVPacket *pkt)
447 struct v4l2_buffer buf = { 0 };
449 struct buff_data *buf_descriptor = pkt->priv;
451 if (pkt->data == NULL)
454 buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
455 buf.memory = V4L2_MEMORY_MMAP;
456 buf.index = buf_descriptor->index;
457 fd = buf_descriptor->fd;
458 av_free(buf_descriptor);
460 res = v4l2_ioctl(fd, VIDIOC_QBUF, &buf);
462 av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n",
469 #if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
470 static int64_t av_gettime_monotonic(void)
474 clock_gettime(CLOCK_MONOTONIC, &tv);
475 return (int64_t)tv.tv_sec * 1000000 + tv.tv_nsec / 1000;
479 static int init_convert_timestamp(AVFormatContext *ctx, int64_t ts)
481 struct video_data *s = ctx->priv_data;
485 if (s->ts_mode == V4L_TS_ABS &&
486 ts <= now + 1 * AV_TIME_BASE && ts >= now - 10 * AV_TIME_BASE) {
487 av_log(ctx, AV_LOG_INFO, "Detected absolute timestamps\n");
488 s->ts_mode = V4L_TS_CONVERT_READY;
491 #if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
492 now = av_gettime_monotonic();
493 if (s->ts_mode == V4L_TS_MONO2ABS ||
494 (ts <= now + 1 * AV_TIME_BASE && ts >= now - 10 * AV_TIME_BASE)) {
495 int64_t period = av_rescale_q(1, ctx->streams[0]->codec->time_base,
497 av_log(ctx, AV_LOG_INFO, "Detected monotonic timestamps, converting\n");
498 /* microseconds instead of seconds, MHz instead of Hz */
499 s->timefilter = ff_timefilter_new(1, period, 1.0E-6);
500 s->ts_mode = V4L_TS_CONVERT_READY;
504 av_log(ctx, AV_LOG_ERROR, "Unknown timestamps\n");
508 static int convert_timestamp(AVFormatContext *ctx, int64_t *ts)
510 struct video_data *s = ctx->priv_data;
513 int r = init_convert_timestamp(ctx, *ts);
517 #if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
519 int64_t nowa = av_gettime();
520 int64_t nowm = av_gettime_monotonic();
521 ff_timefilter_update(s->timefilter, nowa, nowm - s->last_time_m);
522 s->last_time_m = nowm;
523 *ts = ff_timefilter_eval(s->timefilter, *ts - nowm);
529 static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
531 struct video_data *s = ctx->priv_data;
532 struct v4l2_buffer buf = {
533 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
534 .memory = V4L2_MEMORY_MMAP
536 struct buff_data *buf_descriptor;
539 /* FIXME: Some special treatment might be needed in case of loss of signal... */
540 while ((res = v4l2_ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 && (errno == EINTR));
542 if (errno == EAGAIN) {
544 return AVERROR(EAGAIN);
546 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n",
549 return AVERROR(errno);
551 av_assert0(buf.index < s->buffers);
552 if (s->frame_size > 0 && buf.bytesused != s->frame_size) {
553 av_log(ctx, AV_LOG_ERROR,
554 "The v4l2 frame is %d bytes, but %d bytes are expected\n",
555 buf.bytesused, s->frame_size);
557 return AVERROR_INVALIDDATA;
560 /* Image is at s->buff_start[buf.index] */
561 pkt->data= s->buf_start[buf.index];
562 pkt->size = buf.bytesused;
563 pkt->pts = buf.timestamp.tv_sec * INT64_C(1000000) + buf.timestamp.tv_usec;
564 res = convert_timestamp(ctx, &pkt->pts);
567 pkt->destruct = mmap_release_buffer;
568 buf_descriptor = av_malloc(sizeof(struct buff_data));
569 if (buf_descriptor == NULL) {
570 /* Something went wrong... Since av_malloc() failed, we cannot even
571 * allocate a buffer for memcopying into it
573 av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
574 res = v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf);
576 return AVERROR(ENOMEM);
578 buf_descriptor->fd = s->fd;
579 buf_descriptor->index = buf.index;
580 pkt->priv = buf_descriptor;
582 return s->buf_len[buf.index];
585 static int mmap_start(AVFormatContext *ctx)
587 struct video_data *s = ctx->priv_data;
588 enum v4l2_buf_type type;
591 for (i = 0; i < s->buffers; i++) {
592 struct v4l2_buffer buf = {
593 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
595 .memory = V4L2_MEMORY_MMAP
598 res = v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf);
600 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n",
603 return AVERROR(errno);
607 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
608 res = v4l2_ioctl(s->fd, VIDIOC_STREAMON, &type);
610 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n",
613 return AVERROR(errno);
619 static void mmap_close(struct video_data *s)
621 enum v4l2_buf_type type;
624 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
625 /* We do not check for the result, because we could
626 * not do anything about it anyway...
628 v4l2_ioctl(s->fd, VIDIOC_STREAMOFF, &type);
629 for (i = 0; i < s->buffers; i++) {
630 v4l2_munmap(s->buf_start[i], s->buf_len[i]);
632 av_free(s->buf_start);
636 static int v4l2_set_parameters(AVFormatContext *s1)
638 struct video_data *s = s1->priv_data;
639 struct v4l2_input input = { 0 };
640 struct v4l2_standard standard = { 0 };
641 struct v4l2_streamparm streamparm = { 0 };
642 struct v4l2_fract *tpf = &streamparm.parm.capture.timeperframe;
643 AVRational framerate_q = { 0 };
646 streamparm.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
649 (ret = av_parse_video_rate(&framerate_q, s->framerate)) < 0) {
650 av_log(s1, AV_LOG_ERROR, "Could not parse framerate '%s'.\n",
655 /* set tv video input */
656 input.index = s->channel;
657 if (v4l2_ioctl(s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
658 av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl enum input failed:\n");
662 av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set input_id: %d, input: %s\n",
663 s->channel, input.name);
664 if (v4l2_ioctl(s->fd, VIDIOC_S_INPUT, &input.index) < 0) {
665 av_log(s1, AV_LOG_ERROR,
666 "The V4L2 driver ioctl set input(%d) failed\n",
672 av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s\n",
674 /* set tv standard */
677 ret = v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard);
678 if (ret < 0 || !av_strcasecmp(standard.name, s->standard))
682 av_log(s1, AV_LOG_ERROR, "Unknown standard '%s'\n", s->standard);
686 av_log(s1, AV_LOG_DEBUG,
687 "The V4L2 driver set standard: %s, id: %"PRIu64"\n",
688 s->standard, (uint64_t)standard.id);
689 if (v4l2_ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
690 av_log(s1, AV_LOG_ERROR,
691 "The V4L2 driver ioctl set standard(%s) failed\n",
697 if (framerate_q.num && framerate_q.den) {
698 av_log(s1, AV_LOG_DEBUG, "Setting time per frame to %d/%d\n",
699 framerate_q.den, framerate_q.num);
700 tpf->numerator = framerate_q.den;
701 tpf->denominator = framerate_q.num;
703 if (v4l2_ioctl(s->fd, VIDIOC_S_PARM, &streamparm) != 0) {
704 av_log(s1, AV_LOG_ERROR,
705 "ioctl set time per frame(%d/%d) failed\n",
706 framerate_q.den, framerate_q.num);
710 if (framerate_q.num != tpf->denominator ||
711 framerate_q.den != tpf->numerator) {
712 av_log(s1, AV_LOG_INFO,
713 "The driver changed the time per frame from "
715 framerate_q.den, framerate_q.num,
716 tpf->numerator, tpf->denominator);
719 if (v4l2_ioctl(s->fd, VIDIOC_G_PARM, &streamparm) != 0) {
720 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_PARM): %s\n",
722 return AVERROR(errno);
725 s1->streams[0]->codec->time_base.den = tpf->denominator;
726 s1->streams[0]->codec->time_base.num = tpf->numerator;
731 static uint32_t device_try_init(AVFormatContext *s1,
732 enum PixelFormat pix_fmt,
735 enum CodecID *codec_id)
737 uint32_t desired_format = fmt_ff2v4l(pix_fmt, s1->video_codec_id);
739 if (desired_format == 0 ||
740 device_init(s1, width, height, desired_format) < 0) {
744 for (i = 0; i<FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
745 if (s1->video_codec_id == CODEC_ID_NONE ||
746 fmt_conversion_table[i].codec_id == s1->video_codec_id) {
747 desired_format = fmt_conversion_table[i].v4l2_fmt;
748 if (device_init(s1, width, height, desired_format) >= 0) {
756 if (desired_format != 0) {
757 *codec_id = fmt_v4l2codec(desired_format);
758 av_assert0(*codec_id != CODEC_ID_NONE);
761 return desired_format;
764 static int v4l2_read_header(AVFormatContext *s1)
766 struct video_data *s = s1->priv_data;
769 uint32_t desired_format;
770 enum CodecID codec_id;
771 enum PixelFormat pix_fmt = PIX_FMT_NONE;
773 st = avformat_new_stream(s1, NULL);
775 res = AVERROR(ENOMEM);
779 s->fd = device_open(s1);
785 if (s->list_format) {
786 list_formats(s1, s->fd, s->list_format);
791 avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
793 if (s->pixel_format) {
794 AVCodec *codec = avcodec_find_decoder_by_name(s->pixel_format);
797 s1->video_codec_id = codec->id;
799 pix_fmt = av_get_pix_fmt(s->pixel_format);
801 if (pix_fmt == PIX_FMT_NONE && !codec) {
802 av_log(s1, AV_LOG_ERROR, "No such input format: %s.\n",
805 res = AVERROR(EINVAL);
810 if (!s->width && !s->height) {
811 struct v4l2_format fmt;
813 av_log(s1, AV_LOG_VERBOSE,
814 "Querying the device for the current frame size\n");
815 fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
816 if (v4l2_ioctl(s->fd, VIDIOC_G_FMT, &fmt) < 0) {
817 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n",
819 res = AVERROR(errno);
823 s->width = fmt.fmt.pix.width;
824 s->height = fmt.fmt.pix.height;
825 av_log(s1, AV_LOG_VERBOSE,
826 "Setting frame size to %dx%d\n", s->width, s->height);
829 desired_format = device_try_init(s1, pix_fmt, &s->width, &s->height,
831 if (desired_format == 0) {
832 av_log(s1, AV_LOG_ERROR, "Cannot find a proper format for "
833 "codec_id %d, pix_fmt %d.\n", s1->video_codec_id, pix_fmt);
839 if ((res = av_image_check_size(s->width, s->height, 0, s1)) < 0)
842 s->frame_format = desired_format;
844 if ((res = v4l2_set_parameters(s1)) < 0)
847 st->codec->pix_fmt = fmt_v4l2ff(desired_format, codec_id);
849 avpicture_get_size(st->codec->pix_fmt, s->width, s->height);
851 if ((res = mmap_init(s1)) ||
852 (res = mmap_start(s1)) < 0) {
857 s->top_field_first = first_field(s->fd);
859 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
860 st->codec->codec_id = codec_id;
861 if (codec_id == CODEC_ID_RAWVIDEO)
862 st->codec->codec_tag =
863 avcodec_pix_fmt_to_codec_tag(st->codec->pix_fmt);
864 if (desired_format == V4L2_PIX_FMT_YVU420)
865 st->codec->codec_tag = MKTAG('Y', 'V', '1', '2');
866 st->codec->width = s->width;
867 st->codec->height = s->height;
868 st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;
874 static int v4l2_read_packet(AVFormatContext *s1, AVPacket *pkt)
876 struct video_data *s = s1->priv_data;
877 AVFrame *frame = s1->streams[0]->codec->coded_frame;
881 if ((res = mmap_read_frame(s1, pkt)) < 0) {
885 if (frame && s->interlaced) {
886 frame->interlaced_frame = 1;
887 frame->top_field_first = s->top_field_first;
893 static int v4l2_read_close(AVFormatContext *s1)
895 struct video_data *s = s1->priv_data;
903 #define OFFSET(x) offsetof(struct video_data, x)
904 #define DEC AV_OPT_FLAG_DECODING_PARAM
906 static const AVOption options[] = {
907 { "standard", "TV standard, used only by analog frame grabber", OFFSET(standard), AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, DEC },
908 { "channel", "TV channel, used only by frame grabber", OFFSET(channel), AV_OPT_TYPE_INT, {.dbl = 0 }, 0, INT_MAX, DEC },
909 { "video_size", "A string describing frame size, such as 640x480 or hd720.", OFFSET(width), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, DEC },
910 { "pixel_format", "Preferred pixel format", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
911 { "input_format", "Preferred pixel format (for raw video) or codec name", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
912 { "framerate", "", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
913 { "list_formats", "List available formats and exit", OFFSET(list_format), AV_OPT_TYPE_INT, {.dbl = 0 }, 0, INT_MAX, DEC, "list_formats" },
914 { "all", "Show all available formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.dbl = V4L_ALLFORMATS }, 0, INT_MAX, DEC, "list_formats" },
915 { "raw", "Show only non-compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.dbl = V4L_RAWFORMATS }, 0, INT_MAX, DEC, "list_formats" },
916 { "compressed", "Show only compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.dbl = V4L_COMPFORMATS }, 0, INT_MAX, DEC, "list_formats" },
917 { "timestamps", "Kind of timestamps for grabbed frames", OFFSET(ts_mode), AV_OPT_TYPE_INT, {.dbl = 0 }, 0, 2, DEC, "timestamps" },
918 { "default", "Use timestamps from the kernel", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.dbl = V4L_TS_DEFAULT }, 0, 2, DEC, "timestamps" },
919 { "abs", "Use absolute timestamps (wall clock)", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.dbl = V4L_TS_ABS }, 0, 2, DEC, "timestamps" },
920 { "mono2abs", "Force conversion from monotonic to absolute timestamps", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.dbl = V4L_TS_MONO2ABS }, 0, 2, DEC, "timestamps" },
921 { "ts", "Kind of timestamps for grabbed frames", OFFSET(ts_mode), AV_OPT_TYPE_INT, {.dbl = 0 }, 0, 2, DEC, "timestamps" },
925 static const AVClass v4l2_class = {
926 .class_name = "V4L2 indev",
927 .item_name = av_default_item_name,
929 .version = LIBAVUTIL_VERSION_INT,
932 AVInputFormat ff_v4l2_demuxer = {
933 .name = "video4linux2,v4l2",
934 .long_name = NULL_IF_CONFIG_SMALL("Video4Linux2 device grab"),
935 .priv_data_size = sizeof(struct video_data),
936 .read_header = v4l2_read_header,
937 .read_packet = v4l2_read_packet,
938 .read_close = v4l2_read_close,
939 .flags = AVFMT_NOFILE,
940 .priv_class = &v4l2_class,