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 "libavutil/log.h"
27 #include "libavutil/opt.h"
28 #include "libavformat/avformat.h"
29 #include "libavcodec/dsputil.h"
32 #include <sys/ioctl.h>
35 #define _LINUX_TIME_H 1
36 #include <linux/videodev.h>
43 int frame_format; /* see VIDEO_PALETTE_xxx */
48 struct video_capability video_cap;
49 struct video_audio audio_saved;
50 struct video_window video_win;
52 struct video_mbuf gb_buffers;
53 struct video_mmap gb_buf;
61 enum PixelFormat pix_fmt;
62 } video_formats [] = {
63 {.palette = VIDEO_PALETTE_YUV420P, .depth = 12, .pix_fmt = PIX_FMT_YUV420P },
64 {.palette = VIDEO_PALETTE_YUV422, .depth = 16, .pix_fmt = PIX_FMT_YUYV422 },
65 {.palette = VIDEO_PALETTE_UYVY, .depth = 16, .pix_fmt = PIX_FMT_UYVY422 },
66 {.palette = VIDEO_PALETTE_YUYV, .depth = 16, .pix_fmt = PIX_FMT_YUYV422 },
67 /* NOTE: v4l uses BGR24, not RGB24 */
68 {.palette = VIDEO_PALETTE_RGB24, .depth = 24, .pix_fmt = PIX_FMT_BGR24 },
69 {.palette = VIDEO_PALETTE_RGB565, .depth = 16, .pix_fmt = PIX_FMT_BGR565 },
70 {.palette = VIDEO_PALETTE_GREY, .depth = 8, .pix_fmt = PIX_FMT_GRAY8 },
74 static int grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
76 VideoData *s = s1->priv_data;
79 int desired_palette, desired_depth;
80 struct video_tuner tuner;
81 struct video_audio audio;
82 struct video_picture pict;
84 int vformat_num = FF_ARRAY_ELEMS(video_formats);
86 if (ap->time_base.den <= 0) {
87 av_log(s1, AV_LOG_ERROR, "Wrong time base (%d)\n", ap->time_base.den);
90 s->time_base = ap->time_base;
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 if(av_image_check_size(s->video_win.width, s->video_win.height, 0, s1) < 0)
127 desired_palette = -1;
129 for (j = 0; j < vformat_num; j++) {
130 if (ap->pix_fmt == video_formats[j].pix_fmt) {
131 desired_palette = video_formats[j].palette;
132 desired_depth = video_formats[j].depth;
137 /* set tv standard */
138 if (!ioctl(video_fd, VIDIOCGTUNER, &tuner)) {
140 if (!strcasecmp(ap->standard, "pal"))
141 s->standard = VIDEO_MODE_PAL;
142 else if (!strcasecmp(ap->standard, "secam"))
143 s->standard = VIDEO_MODE_SECAM;
145 s->standard = VIDEO_MODE_NTSC;
147 tuner.mode = s->standard;
148 ioctl(video_fd, VIDIOCSTUNER, &tuner);
153 ioctl(video_fd, VIDIOCGAUDIO, &audio);
154 memcpy(&s->audio_saved, &audio, sizeof(audio));
155 audio.flags &= ~VIDEO_AUDIO_MUTE;
156 ioctl(video_fd, VIDIOCSAUDIO, &audio);
158 ioctl(video_fd, VIDIOCGPICT, &pict);
159 av_dlog(s1, "v4l: colour=%d hue=%d brightness=%d constrast=%d whiteness=%d\n",
160 pict.colour, pict.hue, pict.brightness, pict.contrast, pict.whiteness);
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 if (ioctl(video_fd, VIDIOCSWIN, s->video_win) < 0) {
185 av_log(s1, AV_LOG_ERROR, "VIDIOCSWIN: %s\n", strerror(errno));
189 s->frame_format = pict.palette;
192 if (ioctl(video_fd, VIDIOCCAPTURE, &val) < 0) {
193 av_log(s1, AV_LOG_ERROR, "VIDIOCCAPTURE: %s\n", strerror(errno));
197 s->time_frame = av_gettime() * s->time_base.den / s->time_base.num;
200 s->video_buf = mmap(0, s->gb_buffers.size, PROT_READ|PROT_WRITE, MAP_SHARED, video_fd, 0);
201 if ((unsigned char*)-1 == s->video_buf) {
202 s->video_buf = mmap(0, s->gb_buffers.size, PROT_READ|PROT_WRITE, MAP_PRIVATE, video_fd, 0);
203 if ((unsigned char*)-1 == s->video_buf) {
204 av_log(s1, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
209 s->time_frame = av_gettime() * s->time_base.den / s->time_base.num;
211 /* start to grab the first frame */
212 s->gb_buf.frame = s->gb_frame % s->gb_buffers.frames;
213 s->gb_buf.height = s->video_win.height;
214 s->gb_buf.width = s->video_win.width;
215 s->gb_buf.format = pict.palette;
217 if (ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) {
218 if (errno != EAGAIN) {
220 av_log(s1, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno));
222 av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not receive any video signal\n");
226 for (j = 1; j < s->gb_buffers.frames; j++) {
228 ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf);
230 s->frame_format = s->gb_buf.format;
234 for (j = 0; j < vformat_num; j++) {
235 if (s->frame_format == video_formats[j].palette) {
236 s->frame_size = s->video_win.width * s->video_win.height * video_formats[j].depth / 8;
237 st->codec->pix_fmt = video_formats[j].pix_fmt;
242 if (j >= vformat_num)
247 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
248 st->codec->codec_id = CODEC_ID_RAWVIDEO;
249 st->codec->width = s->video_win.width;
250 st->codec->height = s->video_win.height;
251 st->codec->time_base = s->time_base;
252 st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;
261 static int v4l_mm_read_picture(VideoData *s, uint8_t *buf)
265 while (ioctl(s->fd, VIDIOCSYNC, &s->gb_frame) < 0 &&
266 (errno == EAGAIN || errno == EINTR));
268 ptr = s->video_buf + s->gb_buffers.offsets[s->gb_frame];
269 memcpy(buf, ptr, s->frame_size);
271 /* Setup to capture the next frame */
272 s->gb_buf.frame = s->gb_frame;
273 if (ioctl(s->fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) {
275 av_log(NULL, AV_LOG_ERROR, "Cannot Sync\n");
277 av_log(NULL, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno));
281 /* This is now the grabbing frame */
282 s->gb_frame = (s->gb_frame + 1) % s->gb_buffers.frames;
284 return s->frame_size;
287 static int grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
289 VideoData *s = s1->priv_data;
290 int64_t curtime, delay;
293 /* Calculate the time of the next frame */
294 s->time_frame += INT64_C(1000000);
296 /* wait based on the frame rate */
298 curtime = av_gettime();
299 delay = s->time_frame * s->time_base.num / s->time_base.den - curtime;
301 if (delay < INT64_C(-1000000) * s->time_base.num / s->time_base.den) {
302 /* printf("grabbing is %d frames late (dropping)\n", (int) -(delay / 16666)); */
303 s->time_frame += INT64_C(1000000);
307 ts.tv_sec = delay / 1000000;
308 ts.tv_nsec = (delay % 1000000) * 1000;
309 nanosleep(&ts, NULL);
312 if (av_new_packet(pkt, s->frame_size) < 0)
319 return v4l_mm_read_picture(s, pkt->data);
321 if (read(s->fd, pkt->data, pkt->size) != pkt->size)
323 return s->frame_size;
327 static int grab_read_close(AVFormatContext *s1)
329 VideoData *s = s1->priv_data;
332 munmap(s->video_buf, s->gb_buffers.size);
334 /* mute audio. we must force it because the BTTV driver does not
335 return its state correctly */
336 s->audio_saved.flags |= VIDEO_AUDIO_MUTE;
337 ioctl(s->fd, VIDIOCSAUDIO, &s->audio_saved);
343 static const AVOption options[] = {
344 { "standard", "", offsetof(VideoData, standard), FF_OPT_TYPE_INT, {.dbl = VIDEO_MODE_NTSC}, VIDEO_MODE_PAL, VIDEO_MODE_NTSC, AV_OPT_FLAG_DECODING_PARAM, "standard" },
345 { "PAL", "", 0, FF_OPT_TYPE_CONST, {.dbl = VIDEO_MODE_PAL}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
346 { "SECAM", "", 0, FF_OPT_TYPE_CONST, {.dbl = VIDEO_MODE_SECAM}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
347 { "NTSC", "", 0, FF_OPT_TYPE_CONST, {.dbl = VIDEO_MODE_NTSC}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
351 static const AVClass v4l_class = {
352 .class_name = "V4L indev",
353 .item_name = av_default_item_name,
355 .version = LIBAVUTIL_VERSION_INT,
358 AVInputFormat ff_v4l_demuxer = {
360 NULL_IF_CONFIG_SMALL("Video4Linux device grab"),
366 .flags = AVFMT_NOFILE,
367 .priv_class = &v4l_class,