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
22 #undef __STRICT_ANSI__ //workaround due to broken kernel headers
24 #include "libavutil/rational.h"
25 #include "libavformat/avformat.h"
26 #include "libavcodec/dsputil.h"
29 #include <sys/ioctl.h>
32 #define _LINUX_TIME_H 1
33 #include <linux/videodev.h>
39 int frame_format; /* see VIDEO_PALETTE_xxx */
44 struct video_capability video_cap;
45 struct video_audio audio_saved;
46 struct video_window video_win;
48 struct video_mbuf gb_buffers;
49 struct video_mmap gb_buf;
56 enum PixelFormat pix_fmt;
57 } video_formats [] = {
58 {.palette = VIDEO_PALETTE_YUV420P, .depth = 12, .pix_fmt = PIX_FMT_YUV420P },
59 {.palette = VIDEO_PALETTE_YUV422, .depth = 16, .pix_fmt = PIX_FMT_YUYV422 },
60 {.palette = VIDEO_PALETTE_UYVY, .depth = 16, .pix_fmt = PIX_FMT_UYVY422 },
61 {.palette = VIDEO_PALETTE_YUYV, .depth = 16, .pix_fmt = PIX_FMT_YUYV422 },
62 /* NOTE: v4l uses BGR24, not RGB24 */
63 {.palette = VIDEO_PALETTE_RGB24, .depth = 24, .pix_fmt = PIX_FMT_BGR24 },
64 {.palette = VIDEO_PALETTE_RGB565, .depth = 16, .pix_fmt = PIX_FMT_BGR565 },
65 {.palette = VIDEO_PALETTE_GREY, .depth = 8, .pix_fmt = PIX_FMT_GRAY8 },
69 static int grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
71 VideoData *s = s1->priv_data;
74 int desired_palette, desired_depth;
75 struct video_tuner tuner;
76 struct video_audio audio;
77 struct video_picture pict;
79 int vformat_num = FF_ARRAY_ELEMS(video_formats);
81 if (ap->time_base.den <= 0) {
82 av_log(s1, AV_LOG_ERROR, "Wrong time base (%d)\n", ap->time_base.den);
85 s->time_base = ap->time_base;
87 if((unsigned)ap->width > 32767 || (unsigned)ap->height > 32767) {
88 av_log(s1, AV_LOG_ERROR, "Capture size is out of range: %dx%d\n",
89 ap->width, ap->height);
92 s->video_win.width = ap->width;
93 s->video_win.height = ap->height;
95 st = av_new_stream(s1, 0);
97 return AVERROR(ENOMEM);
98 av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
100 video_fd = open(s1->filename, O_RDWR);
102 av_log(s1, AV_LOG_ERROR, "%s: %s\n", s1->filename, strerror(errno));
106 if (ioctl(video_fd, VIDIOCGCAP, &s->video_cap) < 0) {
107 av_log(s1, AV_LOG_ERROR, "VIDIOCGCAP: %s\n", strerror(errno));
111 if (!(s->video_cap.type & VID_TYPE_CAPTURE)) {
112 av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not handle capture\n");
116 /* no values set, autodetect them */
117 if (s->video_win.width <= 0 || s->video_win.height <= 0) {
118 if (ioctl(video_fd, VIDIOCGWIN, &s->video_win, sizeof(s->video_win)) < 0) {
119 av_log(s1, AV_LOG_ERROR, "VIDIOCGWIN: %s\n", strerror(errno));
124 desired_palette = -1;
126 for (j = 0; j < vformat_num; j++) {
127 if (ap->pix_fmt == video_formats[j].pix_fmt) {
128 desired_palette = video_formats[j].palette;
129 desired_depth = video_formats[j].depth;
134 /* set tv standard */
135 if (ap->standard && !ioctl(video_fd, VIDIOCGTUNER, &tuner)) {
136 if (!strcasecmp(ap->standard, "pal"))
137 tuner.mode = VIDEO_MODE_PAL;
138 else if (!strcasecmp(ap->standard, "secam"))
139 tuner.mode = VIDEO_MODE_SECAM;
141 tuner.mode = VIDEO_MODE_NTSC;
142 ioctl(video_fd, VIDIOCSTUNER, &tuner);
147 ioctl(video_fd, VIDIOCGAUDIO, &audio);
148 memcpy(&s->audio_saved, &audio, sizeof(audio));
149 audio.flags &= ~VIDEO_AUDIO_MUTE;
150 ioctl(video_fd, VIDIOCSAUDIO, &audio);
152 ioctl(video_fd, VIDIOCGPICT, &pict);
154 printf("v4l: colour=%d hue=%d brightness=%d constrast=%d whiteness=%d\n",
161 /* try to choose a suitable video format */
162 pict.palette = desired_palette;
163 pict.depth= desired_depth;
164 if (desired_palette == -1 || ioctl(video_fd, VIDIOCSPICT, &pict) < 0) {
165 for (j = 0; j < vformat_num; j++) {
166 pict.palette = video_formats[j].palette;
167 pict.depth = video_formats[j].depth;
168 if (-1 != ioctl(video_fd, VIDIOCSPICT, &pict))
171 if (j >= vformat_num)
175 if (ioctl(video_fd, VIDIOCGMBUF, &s->gb_buffers) < 0) {
176 /* try to use read based access */
181 s->video_win.chromakey = -1;
182 s->video_win.flags = 0;
184 ioctl(video_fd, VIDIOCSWIN, s->video_win);
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, "Fatal: grab device does not support suitable format\n");
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 = CODEC_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 AVInputFormat v4l_demuxer = {
342 NULL_IF_CONFIG_SMALL("video grab"),
348 .flags = AVFMT_NOFILE,