2 * Video4Linux2 grab interface
3 * Copyright (c) 2000,2001 Fabrice Bellard
4 * Copyright (c) 2006 Luca Abeni
6 * Part of this file is based on the V4L2 video capture example
7 * (http://v4l2spec.bytesex.org/v4l2spec/capture.c)
9 * Thanks to Michael Niedermayer for providing the mapping between
10 * V4L2_PIX_FMT_* and AV_PIX_FMT_*
13 * This file is part of Libav.
15 * Libav is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU Lesser General Public
17 * License as published by the Free Software Foundation; either
18 * version 2.1 of the License, or (at your option) any later version.
20 * Libav is distributed in the hope that it will be useful,
21 * but WITHOUT ANY WARRANTY; without even the implied warranty of
22 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
23 * Lesser General Public License for more details.
25 * You should have received a copy of the GNU Lesser General Public
26 * License along with Libav; if not, write to the Free Software
27 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
30 #undef __STRICT_ANSI__ //workaround due to broken kernel headers
32 #include "libavformat/avformat.h"
33 #include "libavformat/internal.h"
36 #include <sys/ioctl.h>
40 #if HAVE_SYS_VIDEOIO_H
41 #include <sys/videoio.h>
43 #include <linux/videodev2.h>
45 #include "libavutil/atomic.h"
46 #include "libavutil/avassert.h"
47 #include "libavutil/imgutils.h"
48 #include "libavutil/internal.h"
49 #include "libavutil/log.h"
50 #include "libavutil/opt.h"
51 #include "libavutil/parseutils.h"
52 #include "libavutil/pixdesc.h"
53 #include "libavutil/avstring.h"
54 #include "libavutil/mathematics.h"
56 static const int desired_video_buffers = 256;
58 #define V4L_ALLFORMATS 3
59 #define V4L_RAWFORMATS 1
60 #define V4L_COMPFORMATS 2
65 int frame_format; /* V4L2_PIX_FMT_* */
73 volatile int buffers_queued;
75 unsigned int *buf_len;
78 char *video_size; /**< String describing video size,
79 set by a private option. */
80 char *pixel_format; /**< Set by a private option. */
81 int list_format; /**< Set by a private option. */
82 char *framerate; /**< Set by a private option. */
92 enum AVPixelFormat ff_fmt;
93 enum AVCodecID codec_id;
97 static struct fmt_map fmt_conversion_table[] = {
98 //ff_fmt codec_id v4l2_fmt
99 { AV_PIX_FMT_YUV420P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV420 },
100 { AV_PIX_FMT_YUV422P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV422P },
101 { AV_PIX_FMT_YUYV422, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUYV },
102 { AV_PIX_FMT_UYVY422, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_UYVY },
103 { AV_PIX_FMT_YUV411P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV411P },
104 { AV_PIX_FMT_YUV410P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV410 },
105 { AV_PIX_FMT_RGB555, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB555 },
106 { AV_PIX_FMT_RGB565, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB565 },
107 { AV_PIX_FMT_BGR24, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_BGR24 },
108 { AV_PIX_FMT_RGB24, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB24 },
109 { AV_PIX_FMT_BGRA, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_BGR32 },
110 { AV_PIX_FMT_GRAY8, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_GREY },
111 { AV_PIX_FMT_NV12, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_NV12 },
112 { AV_PIX_FMT_NONE, AV_CODEC_ID_MJPEG, V4L2_PIX_FMT_MJPEG },
113 { AV_PIX_FMT_NONE, AV_CODEC_ID_MJPEG, V4L2_PIX_FMT_JPEG },
116 static int device_open(AVFormatContext *ctx)
118 struct v4l2_capability cap;
124 if (ctx->flags & AVFMT_FLAG_NONBLOCK) {
128 fd = avpriv_open(ctx->filename, flags);
130 err = AVERROR(errno);
131 av_strerror(err, errbuf, sizeof(errbuf));
133 av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s : %s\n",
134 ctx->filename, errbuf);
139 res = ioctl(fd, VIDIOC_QUERYCAP, &cap);
141 err = AVERROR(errno);
142 av_strerror(err, errbuf, sizeof(errbuf));
143 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
149 av_log(ctx, AV_LOG_VERBOSE, "[%d]Capabilities: %x\n",
150 fd, cap.capabilities);
152 if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {
153 av_log(ctx, AV_LOG_ERROR, "Not a video capture device.\n");
154 err = AVERROR(ENODEV);
159 if (!(cap.capabilities & V4L2_CAP_STREAMING)) {
160 av_log(ctx, AV_LOG_ERROR,
161 "The device does not support the streaming I/O method.\n");
162 err = AVERROR(ENOSYS);
174 static int device_init(AVFormatContext *ctx, int *width, int *height,
177 struct video_data *s = ctx->priv_data;
179 struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
180 struct v4l2_pix_format *pix = &fmt.fmt.pix;
185 pix->height = *height;
186 pix->pixelformat = pix_fmt;
187 pix->field = V4L2_FIELD_ANY;
189 res = ioctl(fd, VIDIOC_S_FMT, &fmt);
191 if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {
192 av_log(ctx, AV_LOG_INFO,
193 "The V4L2 driver changed the video from %dx%d to %dx%d\n",
194 *width, *height, fmt.fmt.pix.width, fmt.fmt.pix.height);
195 *width = fmt.fmt.pix.width;
196 *height = fmt.fmt.pix.height;
199 if (pix_fmt != fmt.fmt.pix.pixelformat) {
200 av_log(ctx, AV_LOG_DEBUG,
201 "The V4L2 driver changed the pixel format "
202 "from 0x%08X to 0x%08X\n",
203 pix_fmt, fmt.fmt.pix.pixelformat);
207 if (fmt.fmt.pix.field == V4L2_FIELD_INTERLACED) {
208 av_log(ctx, AV_LOG_DEBUG, "The V4L2 driver using the interlaced mode");
215 static int first_field(int fd)
220 res = ioctl(fd, VIDIOC_G_STD, &std);
224 if (std & V4L2_STD_NTSC) {
231 static uint32_t fmt_ff2v4l(enum AVPixelFormat pix_fmt, enum AVCodecID codec_id)
235 for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
236 if ((codec_id == AV_CODEC_ID_NONE ||
237 fmt_conversion_table[i].codec_id == codec_id) &&
238 (pix_fmt == AV_PIX_FMT_NONE ||
239 fmt_conversion_table[i].ff_fmt == pix_fmt)) {
240 return fmt_conversion_table[i].v4l2_fmt;
247 static enum AVPixelFormat fmt_v4l2ff(uint32_t v4l2_fmt, enum AVCodecID codec_id)
251 for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
252 if (fmt_conversion_table[i].v4l2_fmt == v4l2_fmt &&
253 fmt_conversion_table[i].codec_id == codec_id) {
254 return fmt_conversion_table[i].ff_fmt;
258 return AV_PIX_FMT_NONE;
261 static enum AVCodecID fmt_v4l2codec(uint32_t v4l2_fmt)
265 for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
266 if (fmt_conversion_table[i].v4l2_fmt == v4l2_fmt) {
267 return fmt_conversion_table[i].codec_id;
271 return AV_CODEC_ID_NONE;
274 #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
275 static void list_framesizes(AVFormatContext *ctx, int fd, uint32_t pixelformat)
277 struct v4l2_frmsizeenum vfse = { .pixel_format = pixelformat };
279 while(!ioctl(fd, VIDIOC_ENUM_FRAMESIZES, &vfse)) {
281 case V4L2_FRMSIZE_TYPE_DISCRETE:
282 av_log(ctx, AV_LOG_INFO, " %ux%u",
283 vfse.discrete.width, vfse.discrete.height);
285 case V4L2_FRMSIZE_TYPE_CONTINUOUS:
286 case V4L2_FRMSIZE_TYPE_STEPWISE:
287 av_log(ctx, AV_LOG_INFO, " {%u-%u, %u}x{%u-%u, %u}",
288 vfse.stepwise.min_width,
289 vfse.stepwise.max_width,
290 vfse.stepwise.step_width,
291 vfse.stepwise.min_height,
292 vfse.stepwise.max_height,
293 vfse.stepwise.step_height);
300 static void list_formats(AVFormatContext *ctx, int fd, int type)
302 struct v4l2_fmtdesc vfd = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
304 while(!ioctl(fd, VIDIOC_ENUM_FMT, &vfd)) {
305 enum AVCodecID codec_id = fmt_v4l2codec(vfd.pixelformat);
306 enum AVPixelFormat pix_fmt = fmt_v4l2ff(vfd.pixelformat, codec_id);
310 if (!(vfd.flags & V4L2_FMT_FLAG_COMPRESSED) &&
311 type & V4L_RAWFORMATS) {
312 const char *fmt_name = av_get_pix_fmt_name(pix_fmt);
313 av_log(ctx, AV_LOG_INFO, "R : %9s : %20s :",
314 fmt_name ? fmt_name : "Unsupported",
316 } else if (vfd.flags & V4L2_FMT_FLAG_COMPRESSED &&
317 type & V4L_COMPFORMATS) {
318 const AVCodecDescriptor *desc = avcodec_descriptor_get(codec_id);
319 av_log(ctx, AV_LOG_INFO, "C : %9s : %20s :",
320 desc ? desc->name : "Unsupported",
326 #ifdef V4L2_FMT_FLAG_EMULATED
327 if (vfd.flags & V4L2_FMT_FLAG_EMULATED) {
328 av_log(ctx, AV_LOG_WARNING, "%s", "Emulated");
332 #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
333 list_framesizes(ctx, fd, vfd.pixelformat);
335 av_log(ctx, AV_LOG_INFO, "\n");
339 static int mmap_init(AVFormatContext *ctx)
342 struct video_data *s = ctx->priv_data;
343 struct v4l2_requestbuffers req = {
344 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
345 .count = desired_video_buffers,
346 .memory = V4L2_MEMORY_MMAP
349 res = ioctl(s->fd, VIDIOC_REQBUFS, &req);
351 res = AVERROR(errno);
352 if (res == AVERROR(EINVAL)) {
353 av_log(ctx, AV_LOG_ERROR, "Device does not support mmap\n");
355 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS)\n");
362 av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");
364 return AVERROR(ENOMEM);
366 s->buffers = req.count;
367 s->buf_start = av_malloc(sizeof(void *) * s->buffers);
369 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
371 return AVERROR(ENOMEM);
373 s->buf_len = av_malloc(sizeof(unsigned int) * s->buffers);
375 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
376 av_free(s->buf_start);
378 return AVERROR(ENOMEM);
381 for (i = 0; i < req.count; i++) {
382 struct v4l2_buffer buf = {
383 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
385 .memory = V4L2_MEMORY_MMAP
388 res = ioctl(s->fd, VIDIOC_QUERYBUF, &buf);
390 res = AVERROR(errno);
391 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF)\n");
396 s->buf_len[i] = buf.length;
397 if (s->frame_size > 0 && s->buf_len[i] < s->frame_size) {
398 av_log(ctx, AV_LOG_ERROR,
399 "Buffer len [%d] = %d != %d\n",
400 i, s->buf_len[i], s->frame_size);
404 s->buf_start[i] = mmap(NULL, buf.length,
405 PROT_READ | PROT_WRITE, MAP_SHARED,
406 s->fd, buf.m.offset);
408 if (s->buf_start[i] == MAP_FAILED) {
410 res = AVERROR(errno);
411 av_strerror(res, errbuf, sizeof(errbuf));
412 av_log(ctx, AV_LOG_ERROR, "mmap: %s\n", errbuf);
421 #if FF_API_DESTRUCT_PACKET
422 static void dummy_release_buffer(AVPacket *pkt)
428 static void mmap_release_buffer(void *opaque, uint8_t *data)
430 struct v4l2_buffer buf = { 0 };
432 struct buff_data *buf_descriptor = opaque;
433 struct video_data *s = buf_descriptor->s;
436 buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
437 buf.memory = V4L2_MEMORY_MMAP;
438 buf.index = buf_descriptor->index;
439 fd = buf_descriptor->fd;
440 av_free(buf_descriptor);
442 res = ioctl(fd, VIDIOC_QBUF, &buf);
444 av_strerror(AVERROR(errno), errbuf, sizeof(errbuf));
445 av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n",
448 avpriv_atomic_int_add_and_fetch(&s->buffers_queued, 1);
451 static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
453 struct video_data *s = ctx->priv_data;
454 struct v4l2_buffer buf = {
455 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
456 .memory = V4L2_MEMORY_MMAP
458 struct pollfd p = { .fd = s->fd, .events = POLLIN };
461 res = poll(&p, 1, s->timeout);
463 return AVERROR(errno);
465 if (!(p.revents & (POLLIN | POLLERR | POLLHUP)))
466 return AVERROR(EAGAIN);
468 /* FIXME: Some special treatment might be needed in case of loss of signal... */
469 while ((res = ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 && (errno == EINTR));
472 if (errno == EAGAIN) {
475 return AVERROR(EAGAIN);
477 res = AVERROR(errno);
478 av_strerror(res, errbuf, sizeof(errbuf));
479 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n",
485 if (buf.index >= s->buffers) {
486 av_log(ctx, AV_LOG_ERROR, "Invalid buffer index received.\n");
487 return AVERROR(EINVAL);
489 avpriv_atomic_int_add_and_fetch(&s->buffers_queued, -1);
490 // always keep at least one buffer queued
491 av_assert0(avpriv_atomic_int_get(&s->buffers_queued) >= 1);
493 if (s->frame_size > 0 && buf.bytesused != s->frame_size) {
494 av_log(ctx, AV_LOG_ERROR,
495 "The v4l2 frame is %d bytes, but %d bytes are expected\n",
496 buf.bytesused, s->frame_size);
498 return AVERROR_INVALIDDATA;
501 /* Image is at s->buff_start[buf.index] */
502 if (avpriv_atomic_int_get(&s->buffers_queued) == FFMAX(s->buffers / 8, 1)) {
503 /* when we start getting low on queued buffers, fall back on copying data */
504 res = av_new_packet(pkt, buf.bytesused);
506 av_log(ctx, AV_LOG_ERROR, "Error allocating a packet.\n");
509 memcpy(pkt->data, s->buf_start[buf.index], buf.bytesused);
511 res = ioctl(s->fd, VIDIOC_QBUF, &buf);
513 res = AVERROR(errno);
514 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF)\n");
518 avpriv_atomic_int_add_and_fetch(&s->buffers_queued, 1);
520 struct buff_data *buf_descriptor;
522 pkt->data = s->buf_start[buf.index];
523 pkt->size = buf.bytesused;
524 #if FF_API_DESTRUCT_PACKET
525 FF_DISABLE_DEPRECATION_WARNINGS
526 pkt->destruct = dummy_release_buffer;
527 FF_ENABLE_DEPRECATION_WARNINGS
530 buf_descriptor = av_malloc(sizeof(struct buff_data));
531 if (!buf_descriptor) {
532 /* Something went wrong... Since av_malloc() failed, we cannot even
533 * allocate a buffer for memcpying into it
535 av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
536 res = ioctl(s->fd, VIDIOC_QBUF, &buf);
538 return AVERROR(ENOMEM);
540 buf_descriptor->fd = s->fd;
541 buf_descriptor->index = buf.index;
542 buf_descriptor->s = s;
544 pkt->buf = av_buffer_create(pkt->data, pkt->size, mmap_release_buffer,
547 av_freep(&buf_descriptor);
548 return AVERROR(ENOMEM);
551 pkt->pts = buf.timestamp.tv_sec * INT64_C(1000000) + buf.timestamp.tv_usec;
553 return s->buf_len[buf.index];
556 static int mmap_start(AVFormatContext *ctx)
558 struct video_data *s = ctx->priv_data;
559 enum v4l2_buf_type type;
563 for (i = 0; i < s->buffers; i++) {
564 struct v4l2_buffer buf = {
565 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
567 .memory = V4L2_MEMORY_MMAP
570 res = ioctl(s->fd, VIDIOC_QBUF, &buf);
572 err = AVERROR(errno);
573 av_strerror(err, errbuf, sizeof(errbuf));
574 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n",
580 s->buffers_queued = s->buffers;
582 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
583 res = ioctl(s->fd, VIDIOC_STREAMON, &type);
585 err = AVERROR(errno);
586 av_strerror(err, errbuf, sizeof(errbuf));
587 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n",
596 static void mmap_close(struct video_data *s)
598 enum v4l2_buf_type type;
601 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
602 /* We do not check for the result, because we could
603 * not do anything about it anyway...
605 ioctl(s->fd, VIDIOC_STREAMOFF, &type);
606 for (i = 0; i < s->buffers; i++) {
607 munmap(s->buf_start[i], s->buf_len[i]);
609 av_free(s->buf_start);
613 static int v4l2_set_parameters(AVFormatContext *s1)
615 struct video_data *s = s1->priv_data;
616 struct v4l2_input input = { 0 };
617 struct v4l2_standard standard = { 0 };
618 struct v4l2_streamparm streamparm = { 0 };
619 struct v4l2_fract *tpf = &streamparm.parm.capture.timeperframe;
620 AVRational framerate_q = { 0 };
623 streamparm.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
626 (ret = av_parse_video_rate(&framerate_q, s->framerate)) < 0) {
627 av_log(s1, AV_LOG_ERROR, "Could not parse framerate '%s'.\n",
632 /* set tv video input */
633 input.index = s->channel;
634 if (ioctl(s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
635 av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl enum input failed:\n");
639 av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set input_id: %d, input: %s\n",
640 s->channel, input.name);
641 if (ioctl(s->fd, VIDIOC_S_INPUT, &input.index) < 0) {
642 av_log(s1, AV_LOG_ERROR,
643 "The V4L2 driver ioctl set input(%d) failed\n",
649 av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s\n",
651 /* set tv standard */
654 if (ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
655 av_log(s1, AV_LOG_ERROR,
656 "The V4L2 driver ioctl set standard(%s) failed\n",
661 if (!av_strcasecmp(standard.name, s->standard)) {
666 av_log(s1, AV_LOG_DEBUG,
667 "The V4L2 driver set standard: %s, id: %"PRIu64"\n",
668 s->standard, (uint64_t)standard.id);
669 if (ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
670 av_log(s1, AV_LOG_ERROR,
671 "The V4L2 driver ioctl set standard(%s) failed\n",
677 if (framerate_q.num && framerate_q.den) {
678 av_log(s1, AV_LOG_DEBUG, "Setting time per frame to %d/%d\n",
679 framerate_q.den, framerate_q.num);
680 tpf->numerator = framerate_q.den;
681 tpf->denominator = framerate_q.num;
683 if (ioctl(s->fd, VIDIOC_S_PARM, &streamparm) != 0) {
684 av_log(s1, AV_LOG_ERROR,
685 "ioctl set time per frame(%d/%d) failed\n",
686 framerate_q.den, framerate_q.num);
690 if (framerate_q.num != tpf->denominator ||
691 framerate_q.den != tpf->numerator) {
692 av_log(s1, AV_LOG_INFO,
693 "The driver changed the time per frame from "
695 framerate_q.den, framerate_q.num,
696 tpf->numerator, tpf->denominator);
699 if (ioctl(s->fd, VIDIOC_G_PARM, &streamparm) != 0) {
701 ret = AVERROR(errno);
702 av_strerror(ret, errbuf, sizeof(errbuf));
703 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_PARM): %s\n",
708 s1->streams[0]->avg_frame_rate.num = tpf->denominator;
709 s1->streams[0]->avg_frame_rate.den = tpf->numerator;
712 av_rescale_q(1, s1->streams[0]->avg_frame_rate,
713 (AVRational){1, 1000});
718 static uint32_t device_try_init(AVFormatContext *s1,
719 enum AVPixelFormat pix_fmt,
722 enum AVCodecID *codec_id)
724 uint32_t desired_format = fmt_ff2v4l(pix_fmt, s1->video_codec_id);
726 if (desired_format == 0 ||
727 device_init(s1, width, height, desired_format) < 0) {
731 for (i = 0; i<FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
732 if (s1->video_codec_id == AV_CODEC_ID_NONE ||
733 fmt_conversion_table[i].codec_id == s1->video_codec_id) {
734 desired_format = fmt_conversion_table[i].v4l2_fmt;
735 if (device_init(s1, width, height, desired_format) >= 0) {
743 if (desired_format != 0) {
744 *codec_id = fmt_v4l2codec(desired_format);
745 assert(*codec_id != AV_CODEC_ID_NONE);
748 return desired_format;
751 static int v4l2_read_header(AVFormatContext *s1)
753 struct video_data *s = s1->priv_data;
756 uint32_t desired_format;
757 enum AVCodecID codec_id;
758 enum AVPixelFormat pix_fmt = AV_PIX_FMT_NONE;
760 st = avformat_new_stream(s1, NULL);
762 return AVERROR(ENOMEM);
764 s->fd = device_open(s1);
768 if (s->list_format) {
769 list_formats(s1, s->fd, s->list_format);
773 avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
776 (res = av_parse_video_size(&s->width, &s->height, s->video_size)) < 0) {
777 av_log(s1, AV_LOG_ERROR, "Could not parse video size '%s'.\n",
782 if (s->pixel_format) {
783 AVCodec *codec = avcodec_find_decoder_by_name(s->pixel_format);
786 s1->video_codec_id = codec->id;
788 pix_fmt = av_get_pix_fmt(s->pixel_format);
790 if (pix_fmt == AV_PIX_FMT_NONE && !codec) {
791 av_log(s1, AV_LOG_ERROR, "No such input format: %s.\n",
794 return AVERROR(EINVAL);
798 if (!s->width && !s->height) {
799 struct v4l2_format fmt;
801 av_log(s1, AV_LOG_VERBOSE,
802 "Querying the device for the current frame size\n");
803 fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
804 if (ioctl(s->fd, VIDIOC_G_FMT, &fmt) < 0) {
806 res = AVERROR(errno);
807 av_strerror(res, errbuf, sizeof(errbuf));
808 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n",
813 s->width = fmt.fmt.pix.width;
814 s->height = fmt.fmt.pix.height;
815 av_log(s1, AV_LOG_VERBOSE,
816 "Setting frame size to %dx%d\n", s->width, s->height);
819 desired_format = device_try_init(s1, pix_fmt, &s->width, &s->height,
821 if (desired_format == 0) {
822 av_log(s1, AV_LOG_ERROR, "Cannot find a proper format for "
823 "codec_id %d, pix_fmt %d.\n", s1->video_codec_id, pix_fmt);
829 if ((res = av_image_check_size(s->width, s->height, 0, s1) < 0))
832 s->frame_format = desired_format;
834 if ((res = v4l2_set_parameters(s1) < 0))
837 st->codec->pix_fmt = fmt_v4l2ff(desired_format, codec_id);
839 avpicture_get_size(st->codec->pix_fmt, s->width, s->height);
841 if ((res = mmap_init(s1)) ||
842 (res = mmap_start(s1)) < 0) {
847 s->top_field_first = first_field(s->fd);
849 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
850 st->codec->codec_id = codec_id;
851 if (codec_id == AV_CODEC_ID_RAWVIDEO)
852 st->codec->codec_tag =
853 avcodec_pix_fmt_to_codec_tag(st->codec->pix_fmt);
854 st->codec->width = s->width;
855 st->codec->height = s->height;
856 st->codec->bit_rate = s->frame_size * av_q2d(st->avg_frame_rate) * 8;
861 static int v4l2_read_packet(AVFormatContext *s1, AVPacket *pkt)
863 struct video_data *s = s1->priv_data;
864 AVFrame *frame = s1->streams[0]->codec->coded_frame;
868 if ((res = mmap_read_frame(s1, pkt)) < 0) {
872 if (frame && s->interlaced) {
873 frame->interlaced_frame = 1;
874 frame->top_field_first = s->top_field_first;
880 static int v4l2_read_close(AVFormatContext *s1)
882 struct video_data *s = s1->priv_data;
884 if (avpriv_atomic_int_get(&s->buffers_queued) != s->buffers)
885 av_log(s1, AV_LOG_WARNING, "Some buffers are still owned by the caller on "
894 #define OFFSET(x) offsetof(struct video_data, x)
895 #define DEC AV_OPT_FLAG_DECODING_PARAM
896 static const AVOption options[] = {
897 { "standard", "TV standard, used only by analog frame grabber", OFFSET(standard), AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, DEC },
898 { "channel", "TV channel, used only by frame grabber", OFFSET(channel), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, DEC },
899 { "video_size", "A string describing frame size, such as 640x480 or hd720.", OFFSET(video_size), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
900 { "pixel_format", "Preferred pixel format", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
901 { "input_format", "Preferred pixel format (for raw video) or codec name", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
902 { "framerate", "", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
903 { "list_formats", "List available formats and exit", OFFSET(list_format), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, DEC, "list_formats" },
904 { "all", "Show all available formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_ALLFORMATS }, 0, INT_MAX, DEC, "list_formats" },
905 { "raw", "Show only non-compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_RAWFORMATS }, 0, INT_MAX, DEC, "list_formats" },
906 { "compressed", "Show only compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_COMPFORMATS }, 0, INT_MAX, DEC, "list_formats" },
910 static const AVClass v4l2_class = {
911 .class_name = "V4L2 indev",
912 .item_name = av_default_item_name,
914 .version = LIBAVUTIL_VERSION_INT,
917 AVInputFormat ff_v4l2_demuxer = {
918 .name = "video4linux2",
919 .long_name = NULL_IF_CONFIG_SMALL("Video4Linux2 device grab"),
920 .priv_data_size = sizeof(struct video_data),
921 .read_header = v4l2_read_header,
922 .read_packet = v4l2_read_packet,
923 .read_close = v4l2_read_close,
924 .flags = AVFMT_NOFILE,
925 .priv_class = &v4l2_class,