2 * Linux video grab interface
3 * Copyright (c) 2000,2001 Fabrice Bellard
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
26 #undef __STRICT_ANSI__ //workaround due to broken kernel headers
28 #include "libavutil/rational.h"
29 #include "libavutil/imgutils.h"
30 #include "libavutil/log.h"
31 #include "libavutil/opt.h"
32 #include "libavcodec/dsputil.h"
35 #include <sys/ioctl.h>
38 #define _LINUX_TIME_H 1
39 #include <linux/videodev.h>
46 int frame_format; /* see VIDEO_PALETTE_xxx */
51 struct video_capability video_cap;
52 struct video_audio audio_saved;
53 struct video_window video_win;
55 struct video_mbuf gb_buffers;
56 struct video_mmap gb_buf;
64 enum PixelFormat pix_fmt;
65 } video_formats [] = {
66 {.palette = VIDEO_PALETTE_YUV420P, .depth = 12, .pix_fmt = PIX_FMT_YUV420P },
67 {.palette = VIDEO_PALETTE_YUV422, .depth = 16, .pix_fmt = PIX_FMT_YUYV422 },
68 {.palette = VIDEO_PALETTE_UYVY, .depth = 16, .pix_fmt = PIX_FMT_UYVY422 },
69 {.palette = VIDEO_PALETTE_YUYV, .depth = 16, .pix_fmt = PIX_FMT_YUYV422 },
70 /* NOTE: v4l uses BGR24, not RGB24 */
71 {.palette = VIDEO_PALETTE_RGB24, .depth = 24, .pix_fmt = PIX_FMT_BGR24 },
72 {.palette = VIDEO_PALETTE_RGB565, .depth = 16, .pix_fmt = PIX_FMT_BGR565 },
73 {.palette = VIDEO_PALETTE_GREY, .depth = 8, .pix_fmt = PIX_FMT_GRAY8 },
77 static int grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
79 VideoData *s = s1->priv_data;
82 int desired_palette, desired_depth;
83 struct video_tuner tuner;
84 struct video_audio audio;
85 struct video_picture pict;
87 int vformat_num = FF_ARRAY_ELEMS(video_formats);
89 av_log(s1, AV_LOG_WARNING, "V4L input device is deprecated and will be removed in the next release.");
91 if (ap->time_base.den <= 0) {
92 av_log(s1, AV_LOG_ERROR, "Wrong time base (%d)\n", ap->time_base.den);
95 s->time_base = ap->time_base;
97 s->video_win.width = ap->width;
98 s->video_win.height = ap->height;
100 st = avformat_new_stream(s1, NULL);
102 return AVERROR(ENOMEM);
103 av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
105 video_fd = open(s1->filename, O_RDWR);
107 av_log(s1, AV_LOG_ERROR, "%s: %s\n", s1->filename, strerror(errno));
111 if (ioctl(video_fd, VIDIOCGCAP, &s->video_cap) < 0) {
112 av_log(s1, AV_LOG_ERROR, "VIDIOCGCAP: %s\n", strerror(errno));
116 if (!(s->video_cap.type & VID_TYPE_CAPTURE)) {
117 av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not handle capture\n");
121 /* no values set, autodetect them */
122 if (s->video_win.width <= 0 || s->video_win.height <= 0) {
123 if (ioctl(video_fd, VIDIOCGWIN, &s->video_win, sizeof(s->video_win)) < 0) {
124 av_log(s1, AV_LOG_ERROR, "VIDIOCGWIN: %s\n", strerror(errno));
129 if(av_image_check_size(s->video_win.width, s->video_win.height, 0, s1) < 0)
132 desired_palette = -1;
134 for (j = 0; j < vformat_num; j++) {
135 if (ap->pix_fmt == video_formats[j].pix_fmt) {
136 desired_palette = video_formats[j].palette;
137 desired_depth = video_formats[j].depth;
142 /* set tv standard */
143 if (!ioctl(video_fd, VIDIOCGTUNER, &tuner)) {
144 tuner.mode = s->standard;
145 ioctl(video_fd, VIDIOCSTUNER, &tuner);
150 ioctl(video_fd, VIDIOCGAUDIO, &audio);
151 memcpy(&s->audio_saved, &audio, sizeof(audio));
152 audio.flags &= ~VIDEO_AUDIO_MUTE;
153 ioctl(video_fd, VIDIOCSAUDIO, &audio);
155 ioctl(video_fd, VIDIOCGPICT, &pict);
156 av_dlog(s1, "v4l: colour=%d hue=%d brightness=%d constrast=%d whiteness=%d\n",
157 pict.colour, pict.hue, pict.brightness, pict.contrast, pict.whiteness);
158 /* try to choose a suitable video format */
159 pict.palette = desired_palette;
160 pict.depth= desired_depth;
161 if (desired_palette == -1 || ioctl(video_fd, VIDIOCSPICT, &pict) < 0) {
162 for (j = 0; j < vformat_num; j++) {
163 pict.palette = video_formats[j].palette;
164 pict.depth = video_formats[j].depth;
165 if (-1 != ioctl(video_fd, VIDIOCSPICT, &pict))
168 if (j >= vformat_num)
172 if (ioctl(video_fd, VIDIOCGMBUF, &s->gb_buffers) < 0) {
173 /* try to use read based access */
178 s->video_win.chromakey = -1;
179 s->video_win.flags = 0;
181 if (ioctl(video_fd, VIDIOCSWIN, s->video_win) < 0) {
182 av_log(s1, AV_LOG_ERROR, "VIDIOCSWIN: %s\n", strerror(errno));
186 s->frame_format = pict.palette;
189 if (ioctl(video_fd, VIDIOCCAPTURE, &val) < 0) {
190 av_log(s1, AV_LOG_ERROR, "VIDIOCCAPTURE: %s\n", strerror(errno));
194 s->time_frame = av_gettime() * s->time_base.den / s->time_base.num;
197 s->video_buf = mmap(0, s->gb_buffers.size, PROT_READ|PROT_WRITE, MAP_SHARED, video_fd, 0);
198 if ((unsigned char*)-1 == s->video_buf) {
199 s->video_buf = mmap(0, s->gb_buffers.size, PROT_READ|PROT_WRITE, MAP_PRIVATE, video_fd, 0);
200 if ((unsigned char*)-1 == s->video_buf) {
201 av_log(s1, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
206 s->time_frame = av_gettime() * s->time_base.den / s->time_base.num;
208 /* start to grab the first frame */
209 s->gb_buf.frame = s->gb_frame % s->gb_buffers.frames;
210 s->gb_buf.height = s->video_win.height;
211 s->gb_buf.width = s->video_win.width;
212 s->gb_buf.format = pict.palette;
214 if (ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) {
215 if (errno != EAGAIN) {
217 av_log(s1, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno));
219 av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not receive any video signal\n");
223 for (j = 1; j < s->gb_buffers.frames; j++) {
225 ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf);
227 s->frame_format = s->gb_buf.format;
231 for (j = 0; j < vformat_num; j++) {
232 if (s->frame_format == video_formats[j].palette) {
233 s->frame_size = s->video_win.width * s->video_win.height * video_formats[j].depth / 8;
234 st->codec->pix_fmt = video_formats[j].pix_fmt;
239 if (j >= vformat_num)
244 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
245 st->codec->codec_id = CODEC_ID_RAWVIDEO;
246 st->codec->width = s->video_win.width;
247 st->codec->height = s->video_win.height;
248 st->codec->time_base = s->time_base;
249 st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;
258 static int v4l_mm_read_picture(VideoData *s, uint8_t *buf)
262 while (ioctl(s->fd, VIDIOCSYNC, &s->gb_frame) < 0 &&
263 (errno == EAGAIN || errno == EINTR));
265 ptr = s->video_buf + s->gb_buffers.offsets[s->gb_frame];
266 memcpy(buf, ptr, s->frame_size);
268 /* Setup to capture the next frame */
269 s->gb_buf.frame = s->gb_frame;
270 if (ioctl(s->fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) {
272 av_log(NULL, AV_LOG_ERROR, "Cannot Sync\n");
274 av_log(NULL, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno));
278 /* This is now the grabbing frame */
279 s->gb_frame = (s->gb_frame + 1) % s->gb_buffers.frames;
281 return s->frame_size;
284 static int grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
286 VideoData *s = s1->priv_data;
287 int64_t curtime, delay;
290 /* Calculate the time of the next frame */
291 s->time_frame += INT64_C(1000000);
293 /* wait based on the frame rate */
295 curtime = av_gettime();
296 delay = s->time_frame * s->time_base.num / s->time_base.den - curtime;
298 if (delay < INT64_C(-1000000) * s->time_base.num / s->time_base.den) {
299 /* printf("grabbing is %d frames late (dropping)\n", (int) -(delay / 16666)); */
300 s->time_frame += INT64_C(1000000);
304 ts.tv_sec = delay / 1000000;
305 ts.tv_nsec = (delay % 1000000) * 1000;
306 nanosleep(&ts, NULL);
309 if (av_new_packet(pkt, s->frame_size) < 0)
316 return v4l_mm_read_picture(s, pkt->data);
318 if (read(s->fd, pkt->data, pkt->size) != pkt->size)
320 return s->frame_size;
324 static int grab_read_close(AVFormatContext *s1)
326 VideoData *s = s1->priv_data;
329 munmap(s->video_buf, s->gb_buffers.size);
331 /* mute audio. we must force it because the BTTV driver does not
332 return its state correctly */
333 s->audio_saved.flags |= VIDEO_AUDIO_MUTE;
334 ioctl(s->fd, VIDIOCSAUDIO, &s->audio_saved);
340 static const AVOption options[] = {
341 { "standard", "", offsetof(VideoData, standard), AV_OPT_TYPE_INT, {.dbl = VIDEO_MODE_NTSC}, VIDEO_MODE_PAL, VIDEO_MODE_NTSC, AV_OPT_FLAG_DECODING_PARAM, "standard" },
342 { "PAL", "", 0, AV_OPT_TYPE_CONST, {.dbl = VIDEO_MODE_PAL}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
343 { "SECAM", "", 0, AV_OPT_TYPE_CONST, {.dbl = VIDEO_MODE_SECAM}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
344 { "NTSC", "", 0, AV_OPT_TYPE_CONST, {.dbl = VIDEO_MODE_NTSC}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
348 static const AVClass v4l_class = {
349 .class_name = "V4L indev",
350 .item_name = av_default_item_name,
352 .version = LIBAVUTIL_VERSION_INT,
355 AVInputFormat ff_v4l_demuxer = {
356 .name = "video4linux,v4l",
357 .long_name = NULL_IF_CONFIG_SMALL("Video4Linux device grab"),
358 .priv_data_size = sizeof(VideoData),
359 .read_header = grab_read_header,
360 .read_packet = grab_read_packet,
361 .read_close = grab_read_close,
362 .flags = AVFMT_NOFILE,
363 .priv_class = &v4l_class,
365 #endif /* FF_API_V4L */