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;
73 int video_fd, frame_size;
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->width <= 0 || ap->height <= 0) {
82 av_log(s1, AV_LOG_ERROR, "Wrong size (%dx%d)\n", ap->width, ap->height);
85 if (ap->time_base.den <= 0) {
86 av_log(s1, AV_LOG_ERROR, "Wrong time base (%d)\n", ap->time_base.den);
89 s->time_base = ap->time_base;
91 if((unsigned)ap->width > 32767 || (unsigned)ap->height > 32767) {
92 av_log(s1, AV_LOG_ERROR, "Capture size is out of range: %dx%d\n",
93 ap->width, ap->height);
96 s->video_win.width = ap->width;
97 s->video_win.height = ap->height;
99 st = av_new_stream(s1, 0);
101 return AVERROR(ENOMEM);
102 av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
104 video_fd = open(s1->filename, O_RDWR);
106 av_log(s1, AV_LOG_ERROR, "%s: %s\n", s1->filename, strerror(errno));
110 if (ioctl(video_fd,VIDIOCGCAP, &s->video_cap) < 0) {
111 av_log(s1, AV_LOG_ERROR, "VIDIOCGCAP: %s\n", strerror(errno));
115 if (!(s->video_cap.type & VID_TYPE_CAPTURE)) {
116 av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not handle capture\n");
120 desired_palette = -1;
122 for (j = 0; j < vformat_num; j++) {
123 if (ap->pix_fmt == video_formats[j].pix_fmt) {
124 desired_palette = video_formats[j].palette;
125 desired_depth = video_formats[j].depth;
130 /* set tv standard */
131 if (ap->standard && !ioctl(video_fd, VIDIOCGTUNER, &tuner)) {
132 if (!strcasecmp(ap->standard, "pal"))
133 tuner.mode = VIDEO_MODE_PAL;
134 else if (!strcasecmp(ap->standard, "secam"))
135 tuner.mode = VIDEO_MODE_SECAM;
137 tuner.mode = VIDEO_MODE_NTSC;
138 ioctl(video_fd, VIDIOCSTUNER, &tuner);
143 ioctl(video_fd, VIDIOCGAUDIO, &audio);
144 memcpy(&s->audio_saved, &audio, sizeof(audio));
145 audio.flags &= ~VIDEO_AUDIO_MUTE;
146 ioctl(video_fd, VIDIOCSAUDIO, &audio);
148 ioctl(video_fd, VIDIOCGPICT, &pict);
150 printf("v4l: colour=%d hue=%d brightness=%d constrast=%d whiteness=%d\n",
157 /* try to choose a suitable video format */
158 pict.palette = desired_palette;
159 pict.depth= desired_depth;
160 if (desired_palette == -1 || ioctl(video_fd, VIDIOCSPICT, &pict) < 0) {
161 for (j = 0; j < vformat_num; j++) {
162 pict.palette = video_formats[j].palette;
163 pict.depth = video_formats[j].depth;
164 if (-1 != ioctl(video_fd, VIDIOCSPICT, &pict))
167 if (j >= vformat_num)
171 if (ioctl(video_fd,VIDIOCGMBUF,&s->gb_buffers) < 0) {
172 /* try to use read based access */
177 s->video_win.chromakey = -1;
178 s->video_win.flags = 0;
180 ioctl(video_fd, VIDIOCSWIN, s->video_win);
182 s->frame_format = pict.palette;
185 ioctl(video_fd, VIDIOCCAPTURE, &val);
187 s->time_frame = av_gettime() * s->time_base.den / s->time_base.num;
190 s->video_buf = mmap(0,s->gb_buffers.size,PROT_READ|PROT_WRITE,MAP_SHARED,video_fd,0);
191 if ((unsigned char*)-1 == s->video_buf) {
192 s->video_buf = mmap(0,s->gb_buffers.size,PROT_READ|PROT_WRITE,MAP_PRIVATE,video_fd,0);
193 if ((unsigned char*)-1 == s->video_buf) {
194 av_log(s1, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
199 s->time_frame = av_gettime() * s->time_base.den / s->time_base.num;
201 /* start to grab the first frame */
202 s->gb_buf.frame = s->gb_frame % s->gb_buffers.frames;
203 s->gb_buf.height = s->video_win.height;
204 s->gb_buf.width = s->video_win.width;
205 s->gb_buf.format = pict.palette;
207 if (ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) {
208 if (errno != EAGAIN) {
210 av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not support suitable format\n");
212 av_log(s1, AV_LOG_ERROR,"Fatal: grab device does not receive any video signal\n");
216 for (j = 1; j < s->gb_buffers.frames; j++) {
218 ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf);
220 s->frame_format = s->gb_buf.format;
224 for (j = 0; j < vformat_num; j++) {
225 if (s->frame_format == video_formats[j].palette) {
226 frame_size = s->video_win.width * s->video_win.height * video_formats[j].depth / 8;
227 st->codec->pix_fmt = video_formats[j].pix_fmt;
232 if (j >= vformat_num)
236 s->frame_size = frame_size;
238 st->codec->codec_type = CODEC_TYPE_VIDEO;
239 st->codec->codec_id = CODEC_ID_RAWVIDEO;
240 st->codec->width = s->video_win.width;
241 st->codec->height = s->video_win.height;
242 st->codec->time_base = s->time_base;
243 st->codec->bit_rate = frame_size * 1/av_q2d(st->codec->time_base) * 8;
252 static int v4l_mm_read_picture(VideoData *s, uint8_t *buf)
256 while (ioctl(s->fd, VIDIOCSYNC, &s->gb_frame) < 0 &&
257 (errno == EAGAIN || errno == EINTR));
259 ptr = s->video_buf + s->gb_buffers.offsets[s->gb_frame];
260 memcpy(buf, ptr, s->frame_size);
262 /* Setup to capture the next frame */
263 s->gb_buf.frame = s->gb_frame;
264 if (ioctl(s->fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) {
266 av_log(NULL, AV_LOG_ERROR, "Cannot Sync\n");
268 av_log(NULL, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno));
272 /* This is now the grabbing frame */
273 s->gb_frame = (s->gb_frame + 1) % s->gb_buffers.frames;
275 return s->frame_size;
278 static int grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
280 VideoData *s = s1->priv_data;
281 int64_t curtime, delay;
284 /* Calculate the time of the next frame */
285 s->time_frame += INT64_C(1000000);
287 /* wait based on the frame rate */
289 curtime = av_gettime();
290 delay = s->time_frame * s->time_base.num / s->time_base.den - curtime;
292 if (delay < INT64_C(-1000000) * s->time_base.num / s->time_base.den) {
293 /* printf("grabbing is %d frames late (dropping)\n", (int) -(delay / 16666)); */
294 s->time_frame += INT64_C(1000000);
298 ts.tv_sec = delay / 1000000;
299 ts.tv_nsec = (delay % 1000000) * 1000;
300 nanosleep(&ts, NULL);
303 if (av_new_packet(pkt, s->frame_size) < 0)
310 return v4l_mm_read_picture(s, pkt->data);
312 if (read(s->fd, pkt->data, pkt->size) != pkt->size)
314 return s->frame_size;
318 static int grab_read_close(AVFormatContext *s1)
320 VideoData *s = s1->priv_data;
323 munmap(s->video_buf, s->gb_buffers.size);
325 /* mute audio. we must force it because the BTTV driver does not
326 return its state correctly */
327 s->audio_saved.flags |= VIDEO_AUDIO_MUTE;
328 ioctl(s->fd, VIDIOCSAUDIO, &s->audio_saved);
334 AVInputFormat v4l_demuxer = {
336 NULL_IF_CONFIG_SMALL("video grab"),
342 .flags = AVFMT_NOFILE,