2 * Linux video grab interface
3 * Copyright (c) 2000,2001 Fabrice Bellard
5 * This file is part of Libav.
7 * Libav 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 * Libav 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 Libav; 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 "libavutil/imgutils.h"
26 #include "libavformat/avformat.h"
27 #include "libavcodec/dsputil.h"
30 #include <sys/ioctl.h>
33 #define _LINUX_TIME_H 1
34 #include <linux/videodev.h>
40 int frame_format; /* see VIDEO_PALETTE_xxx */
45 struct video_capability video_cap;
46 struct video_audio audio_saved;
47 struct video_window video_win;
49 struct video_mbuf gb_buffers;
50 struct video_mmap gb_buf;
57 enum PixelFormat pix_fmt;
58 } video_formats [] = {
59 {.palette = VIDEO_PALETTE_YUV420P, .depth = 12, .pix_fmt = PIX_FMT_YUV420P },
60 {.palette = VIDEO_PALETTE_YUV422, .depth = 16, .pix_fmt = PIX_FMT_YUYV422 },
61 {.palette = VIDEO_PALETTE_UYVY, .depth = 16, .pix_fmt = PIX_FMT_UYVY422 },
62 {.palette = VIDEO_PALETTE_YUYV, .depth = 16, .pix_fmt = PIX_FMT_YUYV422 },
63 /* NOTE: v4l uses BGR24, not RGB24 */
64 {.palette = VIDEO_PALETTE_RGB24, .depth = 24, .pix_fmt = PIX_FMT_BGR24 },
65 {.palette = VIDEO_PALETTE_RGB565, .depth = 16, .pix_fmt = PIX_FMT_BGR565 },
66 {.palette = VIDEO_PALETTE_GREY, .depth = 8, .pix_fmt = PIX_FMT_GRAY8 },
70 static int grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
72 VideoData *s = s1->priv_data;
75 int desired_palette, desired_depth;
76 struct video_tuner tuner;
77 struct video_audio audio;
78 struct video_picture pict;
80 int vformat_num = FF_ARRAY_ELEMS(video_formats);
82 if (ap->time_base.den <= 0) {
83 av_log(s1, AV_LOG_ERROR, "Wrong time base (%d)\n", ap->time_base.den);
86 s->time_base = ap->time_base;
88 s->video_win.width = ap->width;
89 s->video_win.height = ap->height;
91 st = av_new_stream(s1, 0);
93 return AVERROR(ENOMEM);
94 av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
96 video_fd = open(s1->filename, O_RDWR);
98 av_log(s1, AV_LOG_ERROR, "%s: %s\n", s1->filename, strerror(errno));
102 if (ioctl(video_fd, VIDIOCGCAP, &s->video_cap) < 0) {
103 av_log(s1, AV_LOG_ERROR, "VIDIOCGCAP: %s\n", strerror(errno));
107 if (!(s->video_cap.type & VID_TYPE_CAPTURE)) {
108 av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not handle capture\n");
112 /* no values set, autodetect them */
113 if (s->video_win.width <= 0 || s->video_win.height <= 0) {
114 if (ioctl(video_fd, VIDIOCGWIN, &s->video_win, sizeof(s->video_win)) < 0) {
115 av_log(s1, AV_LOG_ERROR, "VIDIOCGWIN: %s\n", strerror(errno));
120 if(av_image_check_size(s->video_win.width, s->video_win.height, 0, s1) < 0)
123 desired_palette = -1;
125 for (j = 0; j < vformat_num; j++) {
126 if (ap->pix_fmt == video_formats[j].pix_fmt) {
127 desired_palette = video_formats[j].palette;
128 desired_depth = video_formats[j].depth;
133 /* set tv standard */
134 if (ap->standard && !ioctl(video_fd, VIDIOCGTUNER, &tuner)) {
135 if (!strcasecmp(ap->standard, "pal"))
136 tuner.mode = VIDEO_MODE_PAL;
137 else if (!strcasecmp(ap->standard, "secam"))
138 tuner.mode = VIDEO_MODE_SECAM;
140 tuner.mode = VIDEO_MODE_NTSC;
141 ioctl(video_fd, VIDIOCSTUNER, &tuner);
146 ioctl(video_fd, VIDIOCGAUDIO, &audio);
147 memcpy(&s->audio_saved, &audio, sizeof(audio));
148 audio.flags &= ~VIDEO_AUDIO_MUTE;
149 ioctl(video_fd, VIDIOCSAUDIO, &audio);
151 ioctl(video_fd, VIDIOCGPICT, &pict);
152 av_dlog(s1, "v4l: colour=%d hue=%d brightness=%d constrast=%d whiteness=%d\n",
153 pict.colour, pict.hue, pict.brightness, pict.contrast, pict.whiteness);
154 /* try to choose a suitable video format */
155 pict.palette = desired_palette;
156 pict.depth= desired_depth;
157 if (desired_palette == -1 || ioctl(video_fd, VIDIOCSPICT, &pict) < 0) {
158 for (j = 0; j < vformat_num; j++) {
159 pict.palette = video_formats[j].palette;
160 pict.depth = video_formats[j].depth;
161 if (-1 != ioctl(video_fd, VIDIOCSPICT, &pict))
164 if (j >= vformat_num)
168 if (ioctl(video_fd, VIDIOCGMBUF, &s->gb_buffers) < 0) {
169 /* try to use read based access */
174 s->video_win.chromakey = -1;
175 s->video_win.flags = 0;
177 if (ioctl(video_fd, VIDIOCSWIN, s->video_win) < 0) {
178 av_log(s1, AV_LOG_ERROR, "VIDIOCSWIN: %s\n", strerror(errno));
182 s->frame_format = pict.palette;
185 if (ioctl(video_fd, VIDIOCCAPTURE, &val) < 0) {
186 av_log(s1, AV_LOG_ERROR, "VIDIOCCAPTURE: %s\n", strerror(errno));
190 s->time_frame = av_gettime() * s->time_base.den / s->time_base.num;
193 s->video_buf = mmap(0, s->gb_buffers.size, PROT_READ|PROT_WRITE, MAP_SHARED, video_fd, 0);
194 if ((unsigned char*)-1 == s->video_buf) {
195 s->video_buf = mmap(0, s->gb_buffers.size, PROT_READ|PROT_WRITE, MAP_PRIVATE, video_fd, 0);
196 if ((unsigned char*)-1 == s->video_buf) {
197 av_log(s1, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
202 s->time_frame = av_gettime() * s->time_base.den / s->time_base.num;
204 /* start to grab the first frame */
205 s->gb_buf.frame = s->gb_frame % s->gb_buffers.frames;
206 s->gb_buf.height = s->video_win.height;
207 s->gb_buf.width = s->video_win.width;
208 s->gb_buf.format = pict.palette;
210 if (ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) {
211 if (errno != EAGAIN) {
213 av_log(s1, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno));
215 av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not receive any video signal\n");
219 for (j = 1; j < s->gb_buffers.frames; j++) {
221 ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf);
223 s->frame_format = s->gb_buf.format;
227 for (j = 0; j < vformat_num; j++) {
228 if (s->frame_format == video_formats[j].palette) {
229 s->frame_size = s->video_win.width * s->video_win.height * video_formats[j].depth / 8;
230 st->codec->pix_fmt = video_formats[j].pix_fmt;
235 if (j >= vformat_num)
240 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
241 st->codec->codec_id = CODEC_ID_RAWVIDEO;
242 st->codec->width = s->video_win.width;
243 st->codec->height = s->video_win.height;
244 st->codec->time_base = s->time_base;
245 st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;
254 static int v4l_mm_read_picture(VideoData *s, uint8_t *buf)
258 while (ioctl(s->fd, VIDIOCSYNC, &s->gb_frame) < 0 &&
259 (errno == EAGAIN || errno == EINTR));
261 ptr = s->video_buf + s->gb_buffers.offsets[s->gb_frame];
262 memcpy(buf, ptr, s->frame_size);
264 /* Setup to capture the next frame */
265 s->gb_buf.frame = s->gb_frame;
266 if (ioctl(s->fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) {
268 av_log(NULL, AV_LOG_ERROR, "Cannot Sync\n");
270 av_log(NULL, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno));
274 /* This is now the grabbing frame */
275 s->gb_frame = (s->gb_frame + 1) % s->gb_buffers.frames;
277 return s->frame_size;
280 static int grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
282 VideoData *s = s1->priv_data;
283 int64_t curtime, delay;
286 /* Calculate the time of the next frame */
287 s->time_frame += INT64_C(1000000);
289 /* wait based on the frame rate */
291 curtime = av_gettime();
292 delay = s->time_frame * s->time_base.num / s->time_base.den - curtime;
294 if (delay < INT64_C(-1000000) * s->time_base.num / s->time_base.den) {
295 /* printf("grabbing is %d frames late (dropping)\n", (int) -(delay / 16666)); */
296 s->time_frame += INT64_C(1000000);
300 ts.tv_sec = delay / 1000000;
301 ts.tv_nsec = (delay % 1000000) * 1000;
302 nanosleep(&ts, NULL);
305 if (av_new_packet(pkt, s->frame_size) < 0)
312 return v4l_mm_read_picture(s, pkt->data);
314 if (read(s->fd, pkt->data, pkt->size) != pkt->size)
316 return s->frame_size;
320 static int grab_read_close(AVFormatContext *s1)
322 VideoData *s = s1->priv_data;
325 munmap(s->video_buf, s->gb_buffers.size);
327 /* mute audio. we must force it because the BTTV driver does not
328 return its state correctly */
329 s->audio_saved.flags |= VIDEO_AUDIO_MUTE;
330 ioctl(s->fd, VIDIOCSAUDIO, &s->audio_saved);
336 AVInputFormat ff_v4l_demuxer = {
338 NULL_IF_CONFIG_SMALL("Video4Linux device grab"),
344 .flags = AVFMT_NOFILE,