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 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"
35 #include <sys/ioctl.h>
38 #if HAVE_SYS_VIDEOIO_H
39 #include <sys/videoio.h>
41 #include <asm/types.h>
42 #include <linux/videodev2.h>
46 #include "libavutil/imgutils.h"
47 #include "libavutil/log.h"
48 #include "libavutil/opt.h"
50 static const int desired_video_buffers = 256;
61 int frame_format; /* V4L2_PIX_FMT_* */
62 enum io_method io_method;
69 unsigned int *buf_len;
80 enum PixelFormat ff_fmt;
81 enum CodecID codec_id;
85 static struct fmt_map fmt_conversion_table[] = {
86 //ff_fmt codec_id v4l2_fmt
87 { PIX_FMT_YUV420P, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV420 },
88 { PIX_FMT_YUV422P, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV422P },
89 { PIX_FMT_YUYV422, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUYV },
90 { PIX_FMT_UYVY422, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_UYVY },
91 { PIX_FMT_YUV411P, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV411P },
92 { PIX_FMT_YUV410P, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV410 },
93 { PIX_FMT_RGB555, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB555 },
94 { PIX_FMT_RGB565, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB565 },
95 { PIX_FMT_BGR24, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_BGR24 },
96 { PIX_FMT_RGB24, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB24 },
97 { PIX_FMT_BGRA, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_BGR32 },
98 { PIX_FMT_GRAY8, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_GREY },
99 { PIX_FMT_NV12, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_NV12 },
100 { PIX_FMT_NONE, CODEC_ID_MJPEG, V4L2_PIX_FMT_MJPEG },
101 { PIX_FMT_NONE, CODEC_ID_MJPEG, V4L2_PIX_FMT_JPEG },
104 static int device_open(AVFormatContext *ctx, uint32_t *capabilities)
106 struct v4l2_capability cap;
111 if (ctx->flags & AVFMT_FLAG_NONBLOCK) {
114 fd = open(ctx->filename, flags, 0);
116 av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s : %s\n",
117 ctx->filename, strerror(errno));
119 return AVERROR(errno);
122 res = ioctl(fd, VIDIOC_QUERYCAP, &cap);
123 // ENOIOCTLCMD definition only availble on __KERNEL__
124 if (res < 0 && ((err = errno) == 515)) {
125 av_log(ctx, AV_LOG_ERROR, "QUERYCAP not implemented, probably V4L device but not supporting V4L2\n");
131 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
137 if ((cap.capabilities & V4L2_CAP_VIDEO_CAPTURE) == 0) {
138 av_log(ctx, AV_LOG_ERROR, "Not a video capture device\n");
141 return AVERROR(ENODEV);
143 *capabilities = cap.capabilities;
148 static int device_init(AVFormatContext *ctx, int *width, int *height, uint32_t pix_fmt)
150 struct video_data *s = ctx->priv_data;
152 struct v4l2_format fmt;
155 memset(&fmt, 0, sizeof(struct v4l2_format));
156 fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
157 fmt.fmt.pix.width = *width;
158 fmt.fmt.pix.height = *height;
159 fmt.fmt.pix.pixelformat = pix_fmt;
160 fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;
161 res = ioctl(fd, VIDIOC_S_FMT, &fmt);
162 if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {
163 av_log(ctx, AV_LOG_INFO, "The V4L2 driver changed the video from %dx%d to %dx%d\n", *width, *height, fmt.fmt.pix.width, fmt.fmt.pix.height);
164 *width = fmt.fmt.pix.width;
165 *height = fmt.fmt.pix.height;
168 if (pix_fmt != fmt.fmt.pix.pixelformat) {
169 av_log(ctx, AV_LOG_DEBUG, "The V4L2 driver changed the pixel format from 0x%08X to 0x%08X\n", pix_fmt, fmt.fmt.pix.pixelformat);
176 static int first_field(int fd)
181 res = ioctl(fd, VIDIOC_G_STD, &std);
185 if (std & V4L2_STD_NTSC) {
192 static uint32_t fmt_ff2v4l(enum PixelFormat pix_fmt, enum CodecID codec_id)
196 for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
197 if ((codec_id == CODEC_ID_NONE ||
198 fmt_conversion_table[i].codec_id == codec_id) &&
199 (pix_fmt == PIX_FMT_NONE ||
200 fmt_conversion_table[i].ff_fmt == pix_fmt)) {
201 return fmt_conversion_table[i].v4l2_fmt;
208 static enum PixelFormat fmt_v4l2ff(uint32_t v4l2_fmt, enum CodecID codec_id)
212 for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
213 if (fmt_conversion_table[i].v4l2_fmt == v4l2_fmt &&
214 fmt_conversion_table[i].codec_id == codec_id) {
215 return fmt_conversion_table[i].ff_fmt;
222 static enum CodecID fmt_v4l2codec(uint32_t v4l2_fmt)
226 for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
227 if (fmt_conversion_table[i].v4l2_fmt == v4l2_fmt) {
228 return fmt_conversion_table[i].codec_id;
232 return CODEC_ID_NONE;
235 static int mmap_init(AVFormatContext *ctx)
237 struct video_data *s = ctx->priv_data;
238 struct v4l2_requestbuffers req;
241 memset(&req, 0, sizeof(struct v4l2_requestbuffers));
242 req.count = desired_video_buffers;
243 req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
244 req.memory = V4L2_MEMORY_MMAP;
245 res = ioctl(s->fd, VIDIOC_REQBUFS, &req);
247 if (errno == EINVAL) {
248 av_log(ctx, AV_LOG_ERROR, "Device does not support mmap\n");
250 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS)\n");
253 return AVERROR(errno);
257 av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");
259 return AVERROR(ENOMEM);
261 s->buffers = req.count;
262 s->buf_start = av_malloc(sizeof(void *) * s->buffers);
263 if (s->buf_start == NULL) {
264 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
266 return AVERROR(ENOMEM);
268 s->buf_len = av_malloc(sizeof(unsigned int) * s->buffers);
269 if (s->buf_len == NULL) {
270 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
271 av_free(s->buf_start);
273 return AVERROR(ENOMEM);
276 for (i = 0; i < req.count; i++) {
277 struct v4l2_buffer buf;
279 memset(&buf, 0, sizeof(struct v4l2_buffer));
280 buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
281 buf.memory = V4L2_MEMORY_MMAP;
283 res = ioctl(s->fd, VIDIOC_QUERYBUF, &buf);
285 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF)\n");
287 return AVERROR(errno);
290 s->buf_len[i] = buf.length;
291 if (s->frame_size > 0 && s->buf_len[i] < s->frame_size) {
292 av_log(ctx, AV_LOG_ERROR, "Buffer len [%d] = %d != %d\n", i, s->buf_len[i], s->frame_size);
296 s->buf_start[i] = mmap (NULL, buf.length,
297 PROT_READ | PROT_WRITE, MAP_SHARED, s->fd, buf.m.offset);
298 if (s->buf_start[i] == MAP_FAILED) {
299 av_log(ctx, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
301 return AVERROR(errno);
308 static int read_init(AVFormatContext *ctx)
313 static void mmap_release_buffer(AVPacket *pkt)
315 struct v4l2_buffer buf;
317 struct buff_data *buf_descriptor = pkt->priv;
319 if (pkt->data == NULL) {
323 memset(&buf, 0, sizeof(struct v4l2_buffer));
324 buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
325 buf.memory = V4L2_MEMORY_MMAP;
326 buf.index = buf_descriptor->index;
327 fd = buf_descriptor->fd;
328 av_free(buf_descriptor);
330 res = ioctl(fd, VIDIOC_QBUF, &buf);
332 av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", strerror(errno));
338 static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
340 struct video_data *s = ctx->priv_data;
341 struct v4l2_buffer buf;
342 struct buff_data *buf_descriptor;
345 memset(&buf, 0, sizeof(struct v4l2_buffer));
346 buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
347 buf.memory = V4L2_MEMORY_MMAP;
349 /* FIXME: Some special treatment might be needed in case of loss of signal... */
350 while ((res = ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 && (errno == EINTR));
352 if (errno == EAGAIN) {
355 return AVERROR(EAGAIN);
357 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n", strerror(errno));
359 return AVERROR(errno);
361 assert (buf.index < s->buffers);
362 if (s->frame_size > 0 && buf.bytesused != s->frame_size) {
363 av_log(ctx, AV_LOG_ERROR, "The v4l2 frame is %d bytes, but %d bytes are expected\n", buf.bytesused, s->frame_size);
365 return AVERROR_INVALIDDATA;
368 /* Image is at s->buff_start[buf.index] */
369 pkt->data= s->buf_start[buf.index];
370 pkt->size = buf.bytesused;
371 pkt->pts = buf.timestamp.tv_sec * INT64_C(1000000) + buf.timestamp.tv_usec;
372 pkt->destruct = mmap_release_buffer;
373 buf_descriptor = av_malloc(sizeof(struct buff_data));
374 if (buf_descriptor == NULL) {
375 /* Something went wrong... Since av_malloc() failed, we cannot even
376 * allocate a buffer for memcopying into it
378 av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
379 res = ioctl(s->fd, VIDIOC_QBUF, &buf);
381 return AVERROR(ENOMEM);
383 buf_descriptor->fd = s->fd;
384 buf_descriptor->index = buf.index;
385 pkt->priv = buf_descriptor;
387 return s->buf_len[buf.index];
390 static int read_frame(AVFormatContext *ctx, AVPacket *pkt)
395 static int mmap_start(AVFormatContext *ctx)
397 struct video_data *s = ctx->priv_data;
398 enum v4l2_buf_type type;
401 for (i = 0; i < s->buffers; i++) {
402 struct v4l2_buffer buf;
404 memset(&buf, 0, sizeof(struct v4l2_buffer));
405 buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
406 buf.memory = V4L2_MEMORY_MMAP;
409 res = ioctl(s->fd, VIDIOC_QBUF, &buf);
411 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", strerror(errno));
413 return AVERROR(errno);
417 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
418 res = ioctl(s->fd, VIDIOC_STREAMON, &type);
420 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n", strerror(errno));
422 return AVERROR(errno);
428 static void mmap_close(struct video_data *s)
430 enum v4l2_buf_type type;
433 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
434 /* We do not check for the result, because we could
435 * not do anything about it anyway...
437 ioctl(s->fd, VIDIOC_STREAMOFF, &type);
438 for (i = 0; i < s->buffers; i++) {
439 munmap(s->buf_start[i], s->buf_len[i]);
441 av_free(s->buf_start);
445 static int v4l2_set_parameters(AVFormatContext *s1, AVFormatParameters *ap)
447 struct video_data *s = s1->priv_data;
448 struct v4l2_input input;
449 struct v4l2_standard standard;
450 struct v4l2_streamparm streamparm = { 0 };
451 struct v4l2_fract *tpf = &streamparm.parm.capture.timeperframe;
454 streamparm.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
457 s->channel = ap->channel;
459 /* set tv video input */
460 memset (&input, 0, sizeof (input));
461 input.index = s->channel;
462 if (ioctl(s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
463 av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl enum input failed:\n");
467 av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set input_id: %d, input: %s\n",
468 s->channel, input.name);
469 if (ioctl(s->fd, VIDIOC_S_INPUT, &input.index) < 0) {
470 av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set input(%d) failed\n",
475 #if FF_API_FORMAT_PARAMETERS
477 av_freep(&s->standard);
478 s->standard = av_strdup(ap->standard);
483 av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s\n",
485 /* set tv standard */
486 memset (&standard, 0, sizeof (standard));
489 if (ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
490 av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set standard(%s) failed\n",
495 if (!strcasecmp(standard.name, s->standard)) {
500 av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s, id: %"PRIu64"\n",
501 s->standard, (uint64_t)standard.id);
502 if (ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
503 av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set standard(%s) failed\n",
508 av_freep(&s->standard);
510 if (ap->time_base.num && ap->time_base.den) {
511 av_log(s1, AV_LOG_DEBUG, "Setting time per frame to %d/%d\n",
512 ap->time_base.num, ap->time_base.den);
513 tpf->numerator = ap->time_base.num;
514 tpf->denominator = ap->time_base.den;
515 if (ioctl(s->fd, VIDIOC_S_PARM, &streamparm) != 0) {
516 av_log(s1, AV_LOG_ERROR,
517 "ioctl set time per frame(%d/%d) failed\n",
518 ap->time_base.num, ap->time_base.den);
522 if (ap->time_base.den != tpf->denominator ||
523 ap->time_base.num != tpf->numerator) {
524 av_log(s1, AV_LOG_INFO,
525 "The driver changed the time per frame from %d/%d to %d/%d\n",
526 ap->time_base.num, ap->time_base.den,
527 tpf->numerator, tpf->denominator);
530 /* if timebase value is not set in ap, read the timebase value from the driver */
531 if (ioctl(s->fd, VIDIOC_G_PARM, &streamparm) != 0) {
532 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_PARM): %s\n", strerror(errno));
533 return AVERROR(errno);
536 ap->time_base.num = tpf->numerator;
537 ap->time_base.den = tpf->denominator;
542 static uint32_t device_try_init(AVFormatContext *s1,
543 const AVFormatParameters *ap,
546 enum CodecID *codec_id)
548 uint32_t desired_format = fmt_ff2v4l(ap->pix_fmt, s1->video_codec_id);
550 if (desired_format == 0 ||
551 device_init(s1, width, height, desired_format) < 0) {
555 for (i = 0; i<FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
556 if (s1->video_codec_id == CODEC_ID_NONE ||
557 fmt_conversion_table[i].codec_id == s1->video_codec_id) {
558 desired_format = fmt_conversion_table[i].v4l2_fmt;
559 if (device_init(s1, width, height, desired_format) >= 0) {
566 if (desired_format != 0) {
567 *codec_id = fmt_v4l2codec(desired_format);
568 assert(*codec_id != CODEC_ID_NONE);
571 return desired_format;
574 static int v4l2_read_header(AVFormatContext *s1, AVFormatParameters *ap)
576 struct video_data *s = s1->priv_data;
579 uint32_t desired_format, capabilities;
580 enum CodecID codec_id;
582 st = av_new_stream(s1, 0);
584 return AVERROR(ENOMEM);
586 av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
588 s->width = ap->width;
589 s->height = ap->height;
592 s->fd = device_open(s1, &capabilities);
596 av_log(s1, AV_LOG_VERBOSE, "[%d]Capabilities: %x\n", s->fd, capabilities);
598 if (!s->width && !s->height) {
599 struct v4l2_format fmt;
601 av_log(s1, AV_LOG_VERBOSE, "Querying the device for the current frame size\n");
602 fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
603 if (ioctl(s->fd, VIDIOC_G_FMT, &fmt) < 0) {
604 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n", strerror(errno));
605 return AVERROR(errno);
607 s->width = fmt.fmt.pix.width;
608 s->height = fmt.fmt.pix.height;
609 av_log(s1, AV_LOG_VERBOSE, "Setting frame size to %dx%d\n", s->width, s->height);
612 desired_format = device_try_init(s1, ap, &s->width, &s->height, &codec_id);
613 if (desired_format == 0) {
614 av_log(s1, AV_LOG_ERROR, "Cannot find a proper format for "
615 "codec_id %d, pix_fmt %d.\n", s1->video_codec_id, ap->pix_fmt);
620 if (av_image_check_size(s->width, s->height, 0, s1) < 0)
621 return AVERROR(EINVAL);
622 s->frame_format = desired_format;
624 if (v4l2_set_parameters(s1, ap) < 0)
627 st->codec->pix_fmt = fmt_v4l2ff(desired_format, codec_id);
628 s->frame_size = avpicture_get_size(st->codec->pix_fmt, s->width, s->height);
629 if (capabilities & V4L2_CAP_STREAMING) {
630 s->io_method = io_mmap;
633 res = mmap_start(s1);
636 s->io_method = io_read;
644 s->top_field_first = first_field(s->fd);
646 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
647 st->codec->codec_id = codec_id;
648 st->codec->width = s->width;
649 st->codec->height = s->height;
650 st->codec->time_base.den = ap->time_base.den;
651 st->codec->time_base.num = ap->time_base.num;
652 st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;
657 static int v4l2_read_packet(AVFormatContext *s1, AVPacket *pkt)
659 struct video_data *s = s1->priv_data;
662 if (s->io_method == io_mmap) {
664 res = mmap_read_frame(s1, pkt);
665 } else if (s->io_method == io_read) {
666 if (av_new_packet(pkt, s->frame_size) < 0)
669 res = read_frame(s1, pkt);
677 if (s1->streams[0]->codec->coded_frame) {
678 s1->streams[0]->codec->coded_frame->interlaced_frame = 1;
679 s1->streams[0]->codec->coded_frame->top_field_first = s->top_field_first;
685 static int v4l2_read_close(AVFormatContext *s1)
687 struct video_data *s = s1->priv_data;
689 if (s->io_method == io_mmap) {
697 static const AVOption options[] = {
698 { "standard", "", offsetof(struct video_data, standard), FF_OPT_TYPE_STRING, {.str = "NTSC" }, 0, 0, AV_OPT_FLAG_DECODING_PARAM },
699 { "channel", "", offsetof(struct video_data, channel), FF_OPT_TYPE_INT, {.dbl = 0 }, 0, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },
703 static const AVClass v4l2_class = {
704 .class_name = "V4L2 indev",
705 .item_name = av_default_item_name,
707 .version = LIBAVUTIL_VERSION_INT,
710 AVInputFormat ff_v4l2_demuxer = {
712 NULL_IF_CONFIG_SMALL("Video4Linux2 device grab"),
713 sizeof(struct video_data),
718 .flags = AVFMT_NOFILE,
719 .priv_class = &v4l2_class,