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/log.h"
49 #include "libavutil/opt.h"
50 #include "libavutil/parseutils.h"
51 #include "libavutil/pixdesc.h"
52 #include "libavutil/avstring.h"
53 #include "libavutil/mathematics.h"
55 static const int desired_video_buffers = 256;
57 #define V4L_ALLFORMATS 3
58 #define V4L_RAWFORMATS 1
59 #define V4L_COMPFORMATS 2
64 int frame_format; /* V4L2_PIX_FMT_* */
72 volatile int buffers_queued;
74 unsigned int *buf_len;
77 char *video_size; /**< String describing video size,
78 set by a private option. */
79 char *pixel_format; /**< Set by a private option. */
80 int list_format; /**< Set by a private option. */
81 char *framerate; /**< Set by a private option. */
91 enum AVPixelFormat ff_fmt;
92 enum AVCodecID codec_id;
96 static struct fmt_map fmt_conversion_table[] = {
97 //ff_fmt codec_id v4l2_fmt
98 { AV_PIX_FMT_YUV420P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV420 },
99 { AV_PIX_FMT_YUV422P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV422P },
100 { AV_PIX_FMT_YUYV422, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUYV },
101 { AV_PIX_FMT_UYVY422, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_UYVY },
102 { AV_PIX_FMT_YUV411P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV411P },
103 { AV_PIX_FMT_YUV410P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV410 },
104 { AV_PIX_FMT_RGB555, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB555 },
105 { AV_PIX_FMT_RGB565, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB565 },
106 { AV_PIX_FMT_BGR24, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_BGR24 },
107 { AV_PIX_FMT_RGB24, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB24 },
108 { AV_PIX_FMT_BGRA, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_BGR32 },
109 { AV_PIX_FMT_GRAY8, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_GREY },
110 { AV_PIX_FMT_NV12, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_NV12 },
111 { AV_PIX_FMT_NONE, AV_CODEC_ID_MJPEG, V4L2_PIX_FMT_MJPEG },
112 { AV_PIX_FMT_NONE, AV_CODEC_ID_MJPEG, V4L2_PIX_FMT_JPEG },
115 static int device_open(AVFormatContext *ctx)
117 struct v4l2_capability cap;
122 if (ctx->flags & AVFMT_FLAG_NONBLOCK) {
126 fd = open(ctx->filename, flags, 0);
130 av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s : %s\n",
131 ctx->filename, strerror(err));
136 res = ioctl(fd, VIDIOC_QUERYCAP, &cap);
139 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
145 av_log(ctx, AV_LOG_VERBOSE, "[%d]Capabilities: %x\n",
146 fd, cap.capabilities);
148 if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {
149 av_log(ctx, AV_LOG_ERROR, "Not a video capture device.\n");
155 if (!(cap.capabilities & V4L2_CAP_STREAMING)) {
156 av_log(ctx, AV_LOG_ERROR,
157 "The device does not support the streaming I/O method.\n");
170 static int device_init(AVFormatContext *ctx, int *width, int *height,
173 struct video_data *s = ctx->priv_data;
175 struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
176 struct v4l2_pix_format *pix = &fmt.fmt.pix;
181 pix->height = *height;
182 pix->pixelformat = pix_fmt;
183 pix->field = V4L2_FIELD_ANY;
185 res = ioctl(fd, VIDIOC_S_FMT, &fmt);
187 if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {
188 av_log(ctx, AV_LOG_INFO,
189 "The V4L2 driver changed the video from %dx%d to %dx%d\n",
190 *width, *height, fmt.fmt.pix.width, fmt.fmt.pix.height);
191 *width = fmt.fmt.pix.width;
192 *height = fmt.fmt.pix.height;
195 if (pix_fmt != fmt.fmt.pix.pixelformat) {
196 av_log(ctx, AV_LOG_DEBUG,
197 "The V4L2 driver changed the pixel format "
198 "from 0x%08X to 0x%08X\n",
199 pix_fmt, fmt.fmt.pix.pixelformat);
203 if (fmt.fmt.pix.field == V4L2_FIELD_INTERLACED) {
204 av_log(ctx, AV_LOG_DEBUG, "The V4L2 driver using the interlaced mode");
211 static int first_field(int fd)
216 res = ioctl(fd, VIDIOC_G_STD, &std);
220 if (std & V4L2_STD_NTSC) {
227 static uint32_t fmt_ff2v4l(enum AVPixelFormat pix_fmt, enum AVCodecID codec_id)
231 for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
232 if ((codec_id == AV_CODEC_ID_NONE ||
233 fmt_conversion_table[i].codec_id == codec_id) &&
234 (pix_fmt == AV_PIX_FMT_NONE ||
235 fmt_conversion_table[i].ff_fmt == pix_fmt)) {
236 return fmt_conversion_table[i].v4l2_fmt;
243 static enum AVPixelFormat fmt_v4l2ff(uint32_t v4l2_fmt, enum AVCodecID codec_id)
247 for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
248 if (fmt_conversion_table[i].v4l2_fmt == v4l2_fmt &&
249 fmt_conversion_table[i].codec_id == codec_id) {
250 return fmt_conversion_table[i].ff_fmt;
254 return AV_PIX_FMT_NONE;
257 static enum AVCodecID fmt_v4l2codec(uint32_t v4l2_fmt)
261 for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
262 if (fmt_conversion_table[i].v4l2_fmt == v4l2_fmt) {
263 return fmt_conversion_table[i].codec_id;
267 return AV_CODEC_ID_NONE;
270 #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
271 static void list_framesizes(AVFormatContext *ctx, int fd, uint32_t pixelformat)
273 struct v4l2_frmsizeenum vfse = { .pixel_format = pixelformat };
275 while(!ioctl(fd, VIDIOC_ENUM_FRAMESIZES, &vfse)) {
277 case V4L2_FRMSIZE_TYPE_DISCRETE:
278 av_log(ctx, AV_LOG_INFO, " %ux%u",
279 vfse.discrete.width, vfse.discrete.height);
281 case V4L2_FRMSIZE_TYPE_CONTINUOUS:
282 case V4L2_FRMSIZE_TYPE_STEPWISE:
283 av_log(ctx, AV_LOG_INFO, " {%u-%u, %u}x{%u-%u, %u}",
284 vfse.stepwise.min_width,
285 vfse.stepwise.max_width,
286 vfse.stepwise.step_width,
287 vfse.stepwise.min_height,
288 vfse.stepwise.max_height,
289 vfse.stepwise.step_height);
296 static void list_formats(AVFormatContext *ctx, int fd, int type)
298 struct v4l2_fmtdesc vfd = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
300 while(!ioctl(fd, VIDIOC_ENUM_FMT, &vfd)) {
301 enum AVCodecID codec_id = fmt_v4l2codec(vfd.pixelformat);
302 enum AVPixelFormat pix_fmt = fmt_v4l2ff(vfd.pixelformat, codec_id);
306 if (!(vfd.flags & V4L2_FMT_FLAG_COMPRESSED) &&
307 type & V4L_RAWFORMATS) {
308 const char *fmt_name = av_get_pix_fmt_name(pix_fmt);
309 av_log(ctx, AV_LOG_INFO, "R : %9s : %20s :",
310 fmt_name ? fmt_name : "Unsupported",
312 } else if (vfd.flags & V4L2_FMT_FLAG_COMPRESSED &&
313 type & V4L_COMPFORMATS) {
314 AVCodec *codec = avcodec_find_encoder(codec_id);
315 av_log(ctx, AV_LOG_INFO, "C : %9s : %20s :",
316 codec ? codec->name : "Unsupported",
322 #ifdef V4L2_FMT_FLAG_EMULATED
323 if (vfd.flags & V4L2_FMT_FLAG_EMULATED) {
324 av_log(ctx, AV_LOG_WARNING, "%s", "Emulated");
328 #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
329 list_framesizes(ctx, fd, vfd.pixelformat);
331 av_log(ctx, AV_LOG_INFO, "\n");
335 static int mmap_init(AVFormatContext *ctx)
338 struct video_data *s = ctx->priv_data;
339 struct v4l2_requestbuffers req = {
340 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
341 .count = desired_video_buffers,
342 .memory = V4L2_MEMORY_MMAP
345 res = ioctl(s->fd, VIDIOC_REQBUFS, &req);
347 if (errno == EINVAL) {
348 av_log(ctx, AV_LOG_ERROR, "Device does not support mmap\n");
350 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS)\n");
353 return AVERROR(errno);
357 av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");
359 return AVERROR(ENOMEM);
361 s->buffers = req.count;
362 s->buf_start = av_malloc(sizeof(void *) * s->buffers);
363 if (s->buf_start == NULL) {
364 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
366 return AVERROR(ENOMEM);
368 s->buf_len = av_malloc(sizeof(unsigned int) * s->buffers);
369 if (s->buf_len == NULL) {
370 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
371 av_free(s->buf_start);
373 return AVERROR(ENOMEM);
376 for (i = 0; i < req.count; i++) {
377 struct v4l2_buffer buf = {
378 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
380 .memory = V4L2_MEMORY_MMAP
383 res = ioctl(s->fd, VIDIOC_QUERYBUF, &buf);
385 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF)\n");
387 return AVERROR(errno);
390 s->buf_len[i] = buf.length;
391 if (s->frame_size > 0 && s->buf_len[i] < s->frame_size) {
392 av_log(ctx, AV_LOG_ERROR,
393 "Buffer len [%d] = %d != %d\n",
394 i, s->buf_len[i], s->frame_size);
398 s->buf_start[i] = mmap(NULL, buf.length,
399 PROT_READ | PROT_WRITE, MAP_SHARED,
400 s->fd, buf.m.offset);
402 if (s->buf_start[i] == MAP_FAILED) {
403 av_log(ctx, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
405 return AVERROR(errno);
412 #if FF_API_DESTRUCT_PACKET
413 static void dummy_release_buffer(AVPacket *pkt)
419 static void mmap_release_buffer(void *opaque, uint8_t *data)
421 struct v4l2_buffer buf = { 0 };
423 struct buff_data *buf_descriptor = opaque;
424 struct video_data *s = buf_descriptor->s;
426 buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
427 buf.memory = V4L2_MEMORY_MMAP;
428 buf.index = buf_descriptor->index;
429 fd = buf_descriptor->fd;
430 av_free(buf_descriptor);
432 res = ioctl(fd, VIDIOC_QBUF, &buf);
434 av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n",
436 avpriv_atomic_int_add_and_fetch(&s->buffers_queued, 1);
439 static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
441 struct video_data *s = ctx->priv_data;
442 struct v4l2_buffer buf = {
443 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
444 .memory = V4L2_MEMORY_MMAP
446 struct pollfd p = { .fd = s->fd, .events = POLLIN };
449 res = poll(&p, 1, s->timeout);
451 return AVERROR(errno);
453 if (!(p.revents & (POLLIN | POLLERR | POLLHUP)))
454 return AVERROR(EAGAIN);
456 /* FIXME: Some special treatment might be needed in case of loss of signal... */
457 while ((res = ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 && (errno == EINTR));
459 if (errno == EAGAIN) {
462 return AVERROR(EAGAIN);
464 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n",
467 return AVERROR(errno);
470 if (buf.index >= s->buffers) {
471 av_log(ctx, AV_LOG_ERROR, "Invalid buffer index received.\n");
472 return AVERROR(EINVAL);
474 avpriv_atomic_int_add_and_fetch(&s->buffers_queued, -1);
475 // always keep at least one buffer queued
476 av_assert0(avpriv_atomic_int_get(&s->buffers_queued) >= 1);
478 if (s->frame_size > 0 && buf.bytesused != s->frame_size) {
479 av_log(ctx, AV_LOG_ERROR,
480 "The v4l2 frame is %d bytes, but %d bytes are expected\n",
481 buf.bytesused, s->frame_size);
483 return AVERROR_INVALIDDATA;
486 /* Image is at s->buff_start[buf.index] */
487 if (avpriv_atomic_int_get(&s->buffers_queued) == FFMAX(s->buffers / 8, 1)) {
488 /* when we start getting low on queued buffers, fall back on copying data */
489 res = av_new_packet(pkt, buf.bytesused);
491 av_log(ctx, AV_LOG_ERROR, "Error allocating a packet.\n");
494 memcpy(pkt->data, s->buf_start[buf.index], buf.bytesused);
496 res = ioctl(s->fd, VIDIOC_QBUF, &buf);
498 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF)\n");
500 return AVERROR(errno);
502 avpriv_atomic_int_add_and_fetch(&s->buffers_queued, 1);
504 struct buff_data *buf_descriptor;
506 pkt->data = s->buf_start[buf.index];
507 pkt->size = buf.bytesused;
508 #if FF_API_DESTRUCT_PACKET
509 pkt->destruct = dummy_release_buffer;
512 buf_descriptor = av_malloc(sizeof(struct buff_data));
513 if (buf_descriptor == NULL) {
514 /* Something went wrong... Since av_malloc() failed, we cannot even
515 * allocate a buffer for memcpying into it
517 av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
518 res = ioctl(s->fd, VIDIOC_QBUF, &buf);
520 return AVERROR(ENOMEM);
522 buf_descriptor->fd = s->fd;
523 buf_descriptor->index = buf.index;
524 buf_descriptor->s = s;
526 pkt->buf = av_buffer_create(pkt->data, pkt->size, mmap_release_buffer,
529 av_freep(&buf_descriptor);
530 return AVERROR(ENOMEM);
533 pkt->pts = buf.timestamp.tv_sec * INT64_C(1000000) + buf.timestamp.tv_usec;
535 return s->buf_len[buf.index];
538 static int mmap_start(AVFormatContext *ctx)
540 struct video_data *s = ctx->priv_data;
541 enum v4l2_buf_type type;
544 for (i = 0; i < s->buffers; i++) {
545 struct v4l2_buffer buf = {
546 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
548 .memory = V4L2_MEMORY_MMAP
551 res = ioctl(s->fd, VIDIOC_QBUF, &buf);
553 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n",
556 return AVERROR(errno);
559 s->buffers_queued = s->buffers;
561 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
562 res = ioctl(s->fd, VIDIOC_STREAMON, &type);
564 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n",
567 return AVERROR(errno);
573 static void mmap_close(struct video_data *s)
575 enum v4l2_buf_type type;
578 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
579 /* We do not check for the result, because we could
580 * not do anything about it anyway...
582 ioctl(s->fd, VIDIOC_STREAMOFF, &type);
583 for (i = 0; i < s->buffers; i++) {
584 munmap(s->buf_start[i], s->buf_len[i]);
586 av_free(s->buf_start);
590 static int v4l2_set_parameters(AVFormatContext *s1)
592 struct video_data *s = s1->priv_data;
593 struct v4l2_input input = { 0 };
594 struct v4l2_standard standard = { 0 };
595 struct v4l2_streamparm streamparm = { 0 };
596 struct v4l2_fract *tpf = &streamparm.parm.capture.timeperframe;
597 AVRational framerate_q = { 0 };
600 streamparm.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
603 (ret = av_parse_video_rate(&framerate_q, s->framerate)) < 0) {
604 av_log(s1, AV_LOG_ERROR, "Could not parse framerate '%s'.\n",
609 /* set tv video input */
610 input.index = s->channel;
611 if (ioctl(s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
612 av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl enum input failed:\n");
616 av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set input_id: %d, input: %s\n",
617 s->channel, input.name);
618 if (ioctl(s->fd, VIDIOC_S_INPUT, &input.index) < 0) {
619 av_log(s1, AV_LOG_ERROR,
620 "The V4L2 driver ioctl set input(%d) failed\n",
626 av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s\n",
628 /* set tv standard */
631 if (ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
632 av_log(s1, AV_LOG_ERROR,
633 "The V4L2 driver ioctl set standard(%s) failed\n",
638 if (!av_strcasecmp(standard.name, s->standard)) {
643 av_log(s1, AV_LOG_DEBUG,
644 "The V4L2 driver set standard: %s, id: %"PRIu64"\n",
645 s->standard, (uint64_t)standard.id);
646 if (ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
647 av_log(s1, AV_LOG_ERROR,
648 "The V4L2 driver ioctl set standard(%s) failed\n",
654 if (framerate_q.num && framerate_q.den) {
655 av_log(s1, AV_LOG_DEBUG, "Setting time per frame to %d/%d\n",
656 framerate_q.den, framerate_q.num);
657 tpf->numerator = framerate_q.den;
658 tpf->denominator = framerate_q.num;
660 if (ioctl(s->fd, VIDIOC_S_PARM, &streamparm) != 0) {
661 av_log(s1, AV_LOG_ERROR,
662 "ioctl set time per frame(%d/%d) failed\n",
663 framerate_q.den, framerate_q.num);
667 if (framerate_q.num != tpf->denominator ||
668 framerate_q.den != tpf->numerator) {
669 av_log(s1, AV_LOG_INFO,
670 "The driver changed the time per frame from "
672 framerate_q.den, framerate_q.num,
673 tpf->numerator, tpf->denominator);
676 if (ioctl(s->fd, VIDIOC_G_PARM, &streamparm) != 0) {
677 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_PARM): %s\n",
679 return AVERROR(errno);
682 s1->streams[0]->avg_frame_rate.num = tpf->denominator;
683 s1->streams[0]->avg_frame_rate.den = tpf->numerator;
686 av_rescale_q(1, s1->streams[0]->avg_frame_rate,
687 (AVRational){1, 1000});
692 static uint32_t device_try_init(AVFormatContext *s1,
693 enum AVPixelFormat pix_fmt,
696 enum AVCodecID *codec_id)
698 uint32_t desired_format = fmt_ff2v4l(pix_fmt, s1->video_codec_id);
700 if (desired_format == 0 ||
701 device_init(s1, width, height, desired_format) < 0) {
705 for (i = 0; i<FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
706 if (s1->video_codec_id == AV_CODEC_ID_NONE ||
707 fmt_conversion_table[i].codec_id == s1->video_codec_id) {
708 desired_format = fmt_conversion_table[i].v4l2_fmt;
709 if (device_init(s1, width, height, desired_format) >= 0) {
717 if (desired_format != 0) {
718 *codec_id = fmt_v4l2codec(desired_format);
719 assert(*codec_id != AV_CODEC_ID_NONE);
722 return desired_format;
725 static int v4l2_read_header(AVFormatContext *s1)
727 struct video_data *s = s1->priv_data;
730 uint32_t desired_format;
731 enum AVCodecID codec_id;
732 enum AVPixelFormat pix_fmt = AV_PIX_FMT_NONE;
734 st = avformat_new_stream(s1, NULL);
736 return AVERROR(ENOMEM);
738 s->fd = device_open(s1);
742 if (s->list_format) {
743 list_formats(s1, s->fd, s->list_format);
747 avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
750 (res = av_parse_video_size(&s->width, &s->height, s->video_size)) < 0) {
751 av_log(s1, AV_LOG_ERROR, "Could not parse video size '%s'.\n",
756 if (s->pixel_format) {
757 AVCodec *codec = avcodec_find_decoder_by_name(s->pixel_format);
760 s1->video_codec_id = codec->id;
762 pix_fmt = av_get_pix_fmt(s->pixel_format);
764 if (pix_fmt == AV_PIX_FMT_NONE && !codec) {
765 av_log(s1, AV_LOG_ERROR, "No such input format: %s.\n",
768 return AVERROR(EINVAL);
772 if (!s->width && !s->height) {
773 struct v4l2_format fmt;
775 av_log(s1, AV_LOG_VERBOSE,
776 "Querying the device for the current frame size\n");
777 fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
778 if (ioctl(s->fd, VIDIOC_G_FMT, &fmt) < 0) {
779 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n",
781 return AVERROR(errno);
784 s->width = fmt.fmt.pix.width;
785 s->height = fmt.fmt.pix.height;
786 av_log(s1, AV_LOG_VERBOSE,
787 "Setting frame size to %dx%d\n", s->width, s->height);
790 desired_format = device_try_init(s1, pix_fmt, &s->width, &s->height,
792 if (desired_format == 0) {
793 av_log(s1, AV_LOG_ERROR, "Cannot find a proper format for "
794 "codec_id %d, pix_fmt %d.\n", s1->video_codec_id, pix_fmt);
800 if ((res = av_image_check_size(s->width, s->height, 0, s1) < 0))
803 s->frame_format = desired_format;
805 if ((res = v4l2_set_parameters(s1) < 0))
808 st->codec->pix_fmt = fmt_v4l2ff(desired_format, codec_id);
810 avpicture_get_size(st->codec->pix_fmt, s->width, s->height);
812 if ((res = mmap_init(s1)) ||
813 (res = mmap_start(s1)) < 0) {
818 s->top_field_first = first_field(s->fd);
820 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
821 st->codec->codec_id = codec_id;
822 if (codec_id == AV_CODEC_ID_RAWVIDEO)
823 st->codec->codec_tag =
824 avcodec_pix_fmt_to_codec_tag(st->codec->pix_fmt);
825 st->codec->width = s->width;
826 st->codec->height = s->height;
827 st->codec->bit_rate = s->frame_size * av_q2d(st->avg_frame_rate) * 8;
832 static int v4l2_read_packet(AVFormatContext *s1, AVPacket *pkt)
834 struct video_data *s = s1->priv_data;
835 AVFrame *frame = s1->streams[0]->codec->coded_frame;
839 if ((res = mmap_read_frame(s1, pkt)) < 0) {
843 if (frame && s->interlaced) {
844 frame->interlaced_frame = 1;
845 frame->top_field_first = s->top_field_first;
851 static int v4l2_read_close(AVFormatContext *s1)
853 struct video_data *s = s1->priv_data;
855 if (avpriv_atomic_int_get(&s->buffers_queued) != s->buffers)
856 av_log(s1, AV_LOG_WARNING, "Some buffers are still owned by the caller on "
865 #define OFFSET(x) offsetof(struct video_data, x)
866 #define DEC AV_OPT_FLAG_DECODING_PARAM
867 static const AVOption options[] = {
868 { "standard", "TV standard, used only by analog frame grabber", OFFSET(standard), AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, DEC },
869 { "channel", "TV channel, used only by frame grabber", OFFSET(channel), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, DEC },
870 { "video_size", "A string describing frame size, such as 640x480 or hd720.", OFFSET(video_size), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
871 { "pixel_format", "Preferred pixel format", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
872 { "input_format", "Preferred pixel format (for raw video) or codec name", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
873 { "framerate", "", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
874 { "list_formats", "List available formats and exit", OFFSET(list_format), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, DEC, "list_formats" },
875 { "all", "Show all available formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_ALLFORMATS }, 0, INT_MAX, DEC, "list_formats" },
876 { "raw", "Show only non-compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_RAWFORMATS }, 0, INT_MAX, DEC, "list_formats" },
877 { "compressed", "Show only compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_COMPFORMATS }, 0, INT_MAX, DEC, "list_formats" },
881 static const AVClass v4l2_class = {
882 .class_name = "V4L2 indev",
883 .item_name = av_default_item_name,
885 .version = LIBAVUTIL_VERSION_INT,
888 AVInputFormat ff_v4l2_demuxer = {
889 .name = "video4linux2",
890 .long_name = NULL_IF_CONFIG_SMALL("Video4Linux2 device grab"),
891 .priv_data_size = sizeof(struct video_data),
892 .read_header = v4l2_read_header,
893 .read_packet = v4l2_read_packet,
894 .read_close = v4l2_read_close,
895 .flags = AVFMT_NOFILE,
896 .priv_class = &v4l2_class,