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 },
114 #ifdef V4L2_PIX_FMT_H264
115 { AV_PIX_FMT_NONE, AV_CODEC_ID_H264, V4L2_PIX_FMT_H264 },
119 static int device_open(AVFormatContext *ctx)
121 struct v4l2_capability cap;
127 if (ctx->flags & AVFMT_FLAG_NONBLOCK) {
131 fd = avpriv_open(ctx->filename, flags);
133 err = AVERROR(errno);
134 av_strerror(err, errbuf, sizeof(errbuf));
136 av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s : %s\n",
137 ctx->filename, errbuf);
142 res = ioctl(fd, VIDIOC_QUERYCAP, &cap);
144 err = AVERROR(errno);
145 av_strerror(err, errbuf, sizeof(errbuf));
146 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
152 av_log(ctx, AV_LOG_VERBOSE, "[%d]Capabilities: %x\n",
153 fd, cap.capabilities);
155 if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {
156 av_log(ctx, AV_LOG_ERROR, "Not a video capture device.\n");
157 err = AVERROR(ENODEV);
162 if (!(cap.capabilities & V4L2_CAP_STREAMING)) {
163 av_log(ctx, AV_LOG_ERROR,
164 "The device does not support the streaming I/O method.\n");
165 err = AVERROR(ENOSYS);
177 static int device_init(AVFormatContext *ctx, int *width, int *height,
180 struct video_data *s = ctx->priv_data;
182 struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
183 struct v4l2_pix_format *pix = &fmt.fmt.pix;
188 pix->height = *height;
189 pix->pixelformat = pix_fmt;
190 pix->field = V4L2_FIELD_ANY;
192 res = ioctl(fd, VIDIOC_S_FMT, &fmt);
194 if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {
195 av_log(ctx, AV_LOG_INFO,
196 "The V4L2 driver changed the video from %dx%d to %dx%d\n",
197 *width, *height, fmt.fmt.pix.width, fmt.fmt.pix.height);
198 *width = fmt.fmt.pix.width;
199 *height = fmt.fmt.pix.height;
202 if (pix_fmt != fmt.fmt.pix.pixelformat) {
203 av_log(ctx, AV_LOG_DEBUG,
204 "The V4L2 driver changed the pixel format "
205 "from 0x%08X to 0x%08X\n",
206 pix_fmt, fmt.fmt.pix.pixelformat);
210 if (fmt.fmt.pix.field == V4L2_FIELD_INTERLACED) {
211 av_log(ctx, AV_LOG_DEBUG, "The V4L2 driver using the interlaced mode");
218 static int first_field(int fd)
223 res = ioctl(fd, VIDIOC_G_STD, &std);
227 if (std & V4L2_STD_NTSC) {
234 static uint32_t fmt_ff2v4l(enum AVPixelFormat pix_fmt, enum AVCodecID codec_id)
238 for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
239 if ((codec_id == AV_CODEC_ID_NONE ||
240 fmt_conversion_table[i].codec_id == codec_id) &&
241 (pix_fmt == AV_PIX_FMT_NONE ||
242 fmt_conversion_table[i].ff_fmt == pix_fmt)) {
243 return fmt_conversion_table[i].v4l2_fmt;
250 static enum AVPixelFormat fmt_v4l2ff(uint32_t v4l2_fmt, enum AVCodecID codec_id)
254 for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
255 if (fmt_conversion_table[i].v4l2_fmt == v4l2_fmt &&
256 fmt_conversion_table[i].codec_id == codec_id) {
257 return fmt_conversion_table[i].ff_fmt;
261 return AV_PIX_FMT_NONE;
264 static enum AVCodecID fmt_v4l2codec(uint32_t v4l2_fmt)
268 for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
269 if (fmt_conversion_table[i].v4l2_fmt == v4l2_fmt) {
270 return fmt_conversion_table[i].codec_id;
274 return AV_CODEC_ID_NONE;
277 #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
278 static void list_framesizes(AVFormatContext *ctx, int fd, uint32_t pixelformat)
280 struct v4l2_frmsizeenum vfse = { .pixel_format = pixelformat };
282 while(!ioctl(fd, VIDIOC_ENUM_FRAMESIZES, &vfse)) {
284 case V4L2_FRMSIZE_TYPE_DISCRETE:
285 av_log(ctx, AV_LOG_INFO, " %ux%u",
286 vfse.discrete.width, vfse.discrete.height);
288 case V4L2_FRMSIZE_TYPE_CONTINUOUS:
289 case V4L2_FRMSIZE_TYPE_STEPWISE:
290 av_log(ctx, AV_LOG_INFO, " {%u-%u, %u}x{%u-%u, %u}",
291 vfse.stepwise.min_width,
292 vfse.stepwise.max_width,
293 vfse.stepwise.step_width,
294 vfse.stepwise.min_height,
295 vfse.stepwise.max_height,
296 vfse.stepwise.step_height);
303 static void list_formats(AVFormatContext *ctx, int fd, int type)
305 struct v4l2_fmtdesc vfd = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
307 while(!ioctl(fd, VIDIOC_ENUM_FMT, &vfd)) {
308 enum AVCodecID codec_id = fmt_v4l2codec(vfd.pixelformat);
309 enum AVPixelFormat pix_fmt = fmt_v4l2ff(vfd.pixelformat, codec_id);
313 if (!(vfd.flags & V4L2_FMT_FLAG_COMPRESSED) &&
314 type & V4L_RAWFORMATS) {
315 const char *fmt_name = av_get_pix_fmt_name(pix_fmt);
316 av_log(ctx, AV_LOG_INFO, "R : %9s : %20s :",
317 fmt_name ? fmt_name : "Unsupported",
319 } else if (vfd.flags & V4L2_FMT_FLAG_COMPRESSED &&
320 type & V4L_COMPFORMATS) {
321 const AVCodecDescriptor *desc = avcodec_descriptor_get(codec_id);
322 av_log(ctx, AV_LOG_INFO, "C : %9s : %20s :",
323 desc ? desc->name : "Unsupported",
329 #ifdef V4L2_FMT_FLAG_EMULATED
330 if (vfd.flags & V4L2_FMT_FLAG_EMULATED) {
331 av_log(ctx, AV_LOG_WARNING, "%s", "Emulated");
335 #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
336 list_framesizes(ctx, fd, vfd.pixelformat);
338 av_log(ctx, AV_LOG_INFO, "\n");
342 static int mmap_init(AVFormatContext *ctx)
345 struct video_data *s = ctx->priv_data;
346 struct v4l2_requestbuffers req = {
347 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
348 .count = desired_video_buffers,
349 .memory = V4L2_MEMORY_MMAP
352 res = ioctl(s->fd, VIDIOC_REQBUFS, &req);
354 res = AVERROR(errno);
355 if (res == AVERROR(EINVAL)) {
356 av_log(ctx, AV_LOG_ERROR, "Device does not support mmap\n");
358 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS)\n");
365 av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");
367 return AVERROR(ENOMEM);
369 s->buffers = req.count;
370 s->buf_start = av_malloc(sizeof(void *) * s->buffers);
372 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
374 return AVERROR(ENOMEM);
376 s->buf_len = av_malloc(sizeof(unsigned int) * s->buffers);
378 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
379 av_free(s->buf_start);
381 return AVERROR(ENOMEM);
384 for (i = 0; i < req.count; i++) {
385 struct v4l2_buffer buf = {
386 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
388 .memory = V4L2_MEMORY_MMAP
391 res = ioctl(s->fd, VIDIOC_QUERYBUF, &buf);
393 res = AVERROR(errno);
394 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF)\n");
399 s->buf_len[i] = buf.length;
400 if (s->frame_size > 0 && s->buf_len[i] < s->frame_size) {
401 av_log(ctx, AV_LOG_ERROR,
402 "Buffer len [%d] = %d != %d\n",
403 i, s->buf_len[i], s->frame_size);
407 s->buf_start[i] = mmap(NULL, buf.length,
408 PROT_READ | PROT_WRITE, MAP_SHARED,
409 s->fd, buf.m.offset);
411 if (s->buf_start[i] == MAP_FAILED) {
413 res = AVERROR(errno);
414 av_strerror(res, errbuf, sizeof(errbuf));
415 av_log(ctx, AV_LOG_ERROR, "mmap: %s\n", errbuf);
424 #if FF_API_DESTRUCT_PACKET
425 static void dummy_release_buffer(AVPacket *pkt)
431 static void mmap_release_buffer(void *opaque, uint8_t *data)
433 struct v4l2_buffer buf = { 0 };
435 struct buff_data *buf_descriptor = opaque;
436 struct video_data *s = buf_descriptor->s;
439 buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
440 buf.memory = V4L2_MEMORY_MMAP;
441 buf.index = buf_descriptor->index;
442 fd = buf_descriptor->fd;
443 av_free(buf_descriptor);
445 res = ioctl(fd, VIDIOC_QBUF, &buf);
447 av_strerror(AVERROR(errno), errbuf, sizeof(errbuf));
448 av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n",
451 avpriv_atomic_int_add_and_fetch(&s->buffers_queued, 1);
454 static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
456 struct video_data *s = ctx->priv_data;
457 struct v4l2_buffer buf = {
458 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
459 .memory = V4L2_MEMORY_MMAP
461 struct pollfd p = { .fd = s->fd, .events = POLLIN };
464 res = poll(&p, 1, s->timeout);
466 return AVERROR(errno);
468 if (!(p.revents & (POLLIN | POLLERR | POLLHUP)))
469 return AVERROR(EAGAIN);
471 /* FIXME: Some special treatment might be needed in case of loss of signal... */
472 while ((res = ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 && (errno == EINTR));
475 if (errno == EAGAIN) {
478 return AVERROR(EAGAIN);
480 res = AVERROR(errno);
481 av_strerror(res, errbuf, sizeof(errbuf));
482 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n",
488 if (buf.index >= s->buffers) {
489 av_log(ctx, AV_LOG_ERROR, "Invalid buffer index received.\n");
490 return AVERROR(EINVAL);
492 avpriv_atomic_int_add_and_fetch(&s->buffers_queued, -1);
493 // always keep at least one buffer queued
494 av_assert0(avpriv_atomic_int_get(&s->buffers_queued) >= 1);
496 if (s->frame_size > 0 && buf.bytesused != s->frame_size) {
497 av_log(ctx, AV_LOG_ERROR,
498 "The v4l2 frame is %d bytes, but %d bytes are expected\n",
499 buf.bytesused, s->frame_size);
501 return AVERROR_INVALIDDATA;
504 /* Image is at s->buff_start[buf.index] */
505 if (avpriv_atomic_int_get(&s->buffers_queued) == FFMAX(s->buffers / 8, 1)) {
506 /* when we start getting low on queued buffers, fall back on copying data */
507 res = av_new_packet(pkt, buf.bytesused);
509 av_log(ctx, AV_LOG_ERROR, "Error allocating a packet.\n");
512 memcpy(pkt->data, s->buf_start[buf.index], buf.bytesused);
514 res = ioctl(s->fd, VIDIOC_QBUF, &buf);
516 res = AVERROR(errno);
517 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF)\n");
521 avpriv_atomic_int_add_and_fetch(&s->buffers_queued, 1);
523 struct buff_data *buf_descriptor;
525 pkt->data = s->buf_start[buf.index];
526 pkt->size = buf.bytesused;
527 #if FF_API_DESTRUCT_PACKET
528 FF_DISABLE_DEPRECATION_WARNINGS
529 pkt->destruct = dummy_release_buffer;
530 FF_ENABLE_DEPRECATION_WARNINGS
533 buf_descriptor = av_malloc(sizeof(struct buff_data));
534 if (!buf_descriptor) {
535 /* Something went wrong... Since av_malloc() failed, we cannot even
536 * allocate a buffer for memcpying into it
538 av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
539 res = ioctl(s->fd, VIDIOC_QBUF, &buf);
541 return AVERROR(ENOMEM);
543 buf_descriptor->fd = s->fd;
544 buf_descriptor->index = buf.index;
545 buf_descriptor->s = s;
547 pkt->buf = av_buffer_create(pkt->data, pkt->size, mmap_release_buffer,
550 av_freep(&buf_descriptor);
551 return AVERROR(ENOMEM);
554 pkt->pts = buf.timestamp.tv_sec * INT64_C(1000000) + buf.timestamp.tv_usec;
556 return s->buf_len[buf.index];
559 static int mmap_start(AVFormatContext *ctx)
561 struct video_data *s = ctx->priv_data;
562 enum v4l2_buf_type type;
566 for (i = 0; i < s->buffers; i++) {
567 struct v4l2_buffer buf = {
568 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
570 .memory = V4L2_MEMORY_MMAP
573 res = ioctl(s->fd, VIDIOC_QBUF, &buf);
575 err = AVERROR(errno);
576 av_strerror(err, errbuf, sizeof(errbuf));
577 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n",
583 s->buffers_queued = s->buffers;
585 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
586 res = ioctl(s->fd, VIDIOC_STREAMON, &type);
588 err = AVERROR(errno);
589 av_strerror(err, errbuf, sizeof(errbuf));
590 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n",
599 static void mmap_close(struct video_data *s)
601 enum v4l2_buf_type type;
604 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
605 /* We do not check for the result, because we could
606 * not do anything about it anyway...
608 ioctl(s->fd, VIDIOC_STREAMOFF, &type);
609 for (i = 0; i < s->buffers; i++) {
610 munmap(s->buf_start[i], s->buf_len[i]);
612 av_free(s->buf_start);
616 static int v4l2_set_parameters(AVFormatContext *s1)
618 struct video_data *s = s1->priv_data;
619 struct v4l2_input input = { 0 };
620 struct v4l2_standard standard = { 0 };
621 struct v4l2_streamparm streamparm = { 0 };
622 struct v4l2_fract *tpf = &streamparm.parm.capture.timeperframe;
623 AVRational framerate_q = { 0 };
626 streamparm.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
629 (ret = av_parse_video_rate(&framerate_q, s->framerate)) < 0) {
630 av_log(s1, AV_LOG_ERROR, "Could not parse framerate '%s'.\n",
635 /* set tv video input */
636 input.index = s->channel;
637 if (ioctl(s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
638 av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl enum input failed:\n");
642 av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set input_id: %d, input: %s\n",
643 s->channel, input.name);
644 if (ioctl(s->fd, VIDIOC_S_INPUT, &input.index) < 0) {
645 av_log(s1, AV_LOG_ERROR,
646 "The V4L2 driver ioctl set input(%d) failed\n",
652 av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s\n",
654 /* set tv standard */
657 if (ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
658 av_log(s1, AV_LOG_ERROR,
659 "The V4L2 driver ioctl set standard(%s) failed\n",
664 if (!av_strcasecmp(standard.name, s->standard)) {
669 av_log(s1, AV_LOG_DEBUG,
670 "The V4L2 driver set standard: %s, id: %"PRIu64"\n",
671 s->standard, (uint64_t)standard.id);
672 if (ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
673 av_log(s1, AV_LOG_ERROR,
674 "The V4L2 driver ioctl set standard(%s) failed\n",
680 if (framerate_q.num && framerate_q.den) {
681 av_log(s1, AV_LOG_DEBUG, "Setting time per frame to %d/%d\n",
682 framerate_q.den, framerate_q.num);
683 tpf->numerator = framerate_q.den;
684 tpf->denominator = framerate_q.num;
686 if (ioctl(s->fd, VIDIOC_S_PARM, &streamparm) != 0) {
687 av_log(s1, AV_LOG_ERROR,
688 "ioctl set time per frame(%d/%d) failed\n",
689 framerate_q.den, framerate_q.num);
693 if (framerate_q.num != tpf->denominator ||
694 framerate_q.den != tpf->numerator) {
695 av_log(s1, AV_LOG_INFO,
696 "The driver changed the time per frame from "
698 framerate_q.den, framerate_q.num,
699 tpf->numerator, tpf->denominator);
702 if (ioctl(s->fd, VIDIOC_G_PARM, &streamparm) != 0) {
704 ret = AVERROR(errno);
705 av_strerror(ret, errbuf, sizeof(errbuf));
706 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_PARM): %s\n",
711 s1->streams[0]->avg_frame_rate.num = tpf->denominator;
712 s1->streams[0]->avg_frame_rate.den = tpf->numerator;
715 av_rescale_q(1, s1->streams[0]->avg_frame_rate,
716 (AVRational){1, 1000});
721 static uint32_t device_try_init(AVFormatContext *s1,
722 enum AVPixelFormat pix_fmt,
725 enum AVCodecID *codec_id)
727 uint32_t desired_format = fmt_ff2v4l(pix_fmt, s1->video_codec_id);
729 if (desired_format == 0 ||
730 device_init(s1, width, height, desired_format) < 0) {
734 for (i = 0; i<FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
735 if (s1->video_codec_id == AV_CODEC_ID_NONE ||
736 fmt_conversion_table[i].codec_id == s1->video_codec_id) {
737 desired_format = fmt_conversion_table[i].v4l2_fmt;
738 if (device_init(s1, width, height, desired_format) >= 0) {
746 if (desired_format != 0) {
747 *codec_id = fmt_v4l2codec(desired_format);
748 assert(*codec_id != AV_CODEC_ID_NONE);
751 return desired_format;
754 static int v4l2_read_header(AVFormatContext *s1)
756 struct video_data *s = s1->priv_data;
759 uint32_t desired_format;
760 enum AVCodecID codec_id;
761 enum AVPixelFormat pix_fmt = AV_PIX_FMT_NONE;
763 st = avformat_new_stream(s1, NULL);
765 return AVERROR(ENOMEM);
767 s->fd = device_open(s1);
771 if (s->list_format) {
772 list_formats(s1, s->fd, s->list_format);
776 avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
779 (res = av_parse_video_size(&s->width, &s->height, s->video_size)) < 0) {
780 av_log(s1, AV_LOG_ERROR, "Could not parse video size '%s'.\n",
785 if (s->pixel_format) {
786 AVCodec *codec = avcodec_find_decoder_by_name(s->pixel_format);
789 s1->video_codec_id = codec->id;
790 st->need_parsing = AVSTREAM_PARSE_HEADERS;
793 pix_fmt = av_get_pix_fmt(s->pixel_format);
795 if (pix_fmt == AV_PIX_FMT_NONE && !codec) {
796 av_log(s1, AV_LOG_ERROR, "No such input format: %s.\n",
799 return AVERROR(EINVAL);
803 if (!s->width && !s->height) {
804 struct v4l2_format fmt;
806 av_log(s1, AV_LOG_VERBOSE,
807 "Querying the device for the current frame size\n");
808 fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
809 if (ioctl(s->fd, VIDIOC_G_FMT, &fmt) < 0) {
811 res = AVERROR(errno);
812 av_strerror(res, errbuf, sizeof(errbuf));
813 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n",
818 s->width = fmt.fmt.pix.width;
819 s->height = fmt.fmt.pix.height;
820 av_log(s1, AV_LOG_VERBOSE,
821 "Setting frame size to %dx%d\n", s->width, s->height);
824 desired_format = device_try_init(s1, pix_fmt, &s->width, &s->height,
826 if (desired_format == 0) {
827 av_log(s1, AV_LOG_ERROR, "Cannot find a proper format for "
828 "codec_id %d, pix_fmt %d.\n", s1->video_codec_id, pix_fmt);
834 if ((res = av_image_check_size(s->width, s->height, 0, s1) < 0))
837 s->frame_format = desired_format;
839 if ((res = v4l2_set_parameters(s1) < 0))
842 st->codec->pix_fmt = fmt_v4l2ff(desired_format, codec_id);
844 avpicture_get_size(st->codec->pix_fmt, s->width, s->height);
846 if ((res = mmap_init(s1)) ||
847 (res = mmap_start(s1)) < 0) {
852 s->top_field_first = first_field(s->fd);
854 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
855 st->codec->codec_id = codec_id;
856 if (codec_id == AV_CODEC_ID_RAWVIDEO)
857 st->codec->codec_tag =
858 avcodec_pix_fmt_to_codec_tag(st->codec->pix_fmt);
859 st->codec->width = s->width;
860 st->codec->height = s->height;
861 st->codec->bit_rate = s->frame_size * av_q2d(st->avg_frame_rate) * 8;
866 static int v4l2_read_packet(AVFormatContext *s1, AVPacket *pkt)
868 struct video_data *s = s1->priv_data;
869 #if FF_API_CODED_FRAME
870 FF_DISABLE_DEPRECATION_WARNINGS
871 AVFrame *frame = s1->streams[0]->codec->coded_frame;
872 FF_ENABLE_DEPRECATION_WARNINGS
877 if ((res = mmap_read_frame(s1, pkt)) < 0) {
881 #if FF_API_CODED_FRAME
882 FF_DISABLE_DEPRECATION_WARNINGS
883 if (frame && s->interlaced) {
884 frame->interlaced_frame = 1;
885 frame->top_field_first = s->top_field_first;
887 FF_ENABLE_DEPRECATION_WARNINGS
893 static int v4l2_read_close(AVFormatContext *s1)
895 struct video_data *s = s1->priv_data;
897 if (avpriv_atomic_int_get(&s->buffers_queued) != s->buffers)
898 av_log(s1, AV_LOG_WARNING, "Some buffers are still owned by the caller on "
907 #define OFFSET(x) offsetof(struct video_data, x)
908 #define DEC AV_OPT_FLAG_DECODING_PARAM
909 static const AVOption options[] = {
910 { "standard", "TV standard, used only by analog frame grabber", OFFSET(standard), AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, DEC },
911 { "channel", "TV channel, used only by frame grabber", OFFSET(channel), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, DEC },
912 { "video_size", "A string describing frame size, such as 640x480 or hd720.", OFFSET(video_size), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
913 { "pixel_format", "Preferred pixel format", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
914 { "input_format", "Preferred pixel format (for raw video) or codec name", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
915 { "framerate", "", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
916 { "list_formats", "List available formats and exit", OFFSET(list_format), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, DEC, "list_formats" },
917 { "all", "Show all available formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_ALLFORMATS }, 0, INT_MAX, DEC, "list_formats" },
918 { "raw", "Show only non-compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_RAWFORMATS }, 0, INT_MAX, DEC, "list_formats" },
919 { "compressed", "Show only compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_COMPFORMATS }, 0, INT_MAX, DEC, "list_formats" },
923 static const AVClass v4l2_class = {
924 .class_name = "V4L2 indev",
925 .item_name = av_default_item_name,
927 .version = LIBAVUTIL_VERSION_INT,
930 AVInputFormat ff_v4l2_demuxer = {
931 .name = "video4linux2",
932 .long_name = NULL_IF_CONFIG_SMALL("Video4Linux2 device grab"),
933 .priv_data_size = sizeof(struct video_data),
934 .read_header = v4l2_read_header,
935 .read_packet = v4l2_read_packet,
936 .read_close = v4l2_read_close,
937 .flags = AVFMT_NOFILE,
938 .priv_class = &v4l2_class,