1/* 2 * Linux video grab interface 3 * Copyright (c) 2000,2001 Fabrice Bellard 4 * 5 * This file is part of FFmpeg. 6 * 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. 11 * 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. 16 * 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 20 */ 21 22#undef __STRICT_ANSI__ //workaround due to broken kernel headers 23#include "config.h" 24#include "libavutil/rational.h" 25#include "libavformat/avformat.h" 26#include "libavcodec/dsputil.h" 27#include <unistd.h> 28#include <fcntl.h> 29#include <sys/ioctl.h> 30#include <sys/mman.h> 31#include <sys/time.h> 32#define _LINUX_TIME_H 1 33#include <linux/videodev.h> 34#include <time.h> 35#include <strings.h> 36 37typedef struct { 38 int fd; 39 int frame_format; /* see VIDEO_PALETTE_xxx */ 40 int use_mmap; 41 AVRational time_base; 42 int64_t time_frame; 43 int frame_size; 44 struct video_capability video_cap; 45 struct video_audio audio_saved; 46 struct video_window video_win; 47 uint8_t *video_buf; 48 struct video_mbuf gb_buffers; 49 struct video_mmap gb_buf; 50 int gb_frame; 51} VideoData; 52 53static const struct { 54 int palette; 55 int depth; 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 }, 66}; 67 68 69static int grab_read_header(AVFormatContext *s1, AVFormatParameters *ap) 70{ 71 VideoData *s = s1->priv_data; 72 AVStream *st; 73 int video_fd; 74 int desired_palette, desired_depth; 75 struct video_tuner tuner; 76 struct video_audio audio; 77 struct video_picture pict; 78 int j; 79 int vformat_num = FF_ARRAY_ELEMS(video_formats); 80 81 if (ap->time_base.den <= 0) { 82 av_log(s1, AV_LOG_ERROR, "Wrong time base (%d)\n", ap->time_base.den); 83 return -1; 84 } 85 s->time_base = ap->time_base; 86 87 s->video_win.width = ap->width; 88 s->video_win.height = ap->height; 89 90 st = av_new_stream(s1, 0); 91 if (!st) 92 return AVERROR(ENOMEM); 93 av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */ 94 95 video_fd = open(s1->filename, O_RDWR); 96 if (video_fd < 0) { 97 av_log(s1, AV_LOG_ERROR, "%s: %s\n", s1->filename, strerror(errno)); 98 goto fail; 99 } 100 101 if (ioctl(video_fd, VIDIOCGCAP, &s->video_cap) < 0) { 102 av_log(s1, AV_LOG_ERROR, "VIDIOCGCAP: %s\n", strerror(errno)); 103 goto fail; 104 } 105 106 if (!(s->video_cap.type & VID_TYPE_CAPTURE)) { 107 av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not handle capture\n"); 108 goto fail; 109 } 110 111 /* no values set, autodetect them */ 112 if (s->video_win.width <= 0 || s->video_win.height <= 0) { 113 if (ioctl(video_fd, VIDIOCGWIN, &s->video_win, sizeof(s->video_win)) < 0) { 114 av_log(s1, AV_LOG_ERROR, "VIDIOCGWIN: %s\n", strerror(errno)); 115 goto fail; 116 } 117 } 118 119 if(avcodec_check_dimensions(s1, s->video_win.width, s->video_win.height) < 0) 120 return -1; 121 122 desired_palette = -1; 123 desired_depth = -1; 124 for (j = 0; j < vformat_num; j++) { 125 if (ap->pix_fmt == video_formats[j].pix_fmt) { 126 desired_palette = video_formats[j].palette; 127 desired_depth = video_formats[j].depth; 128 break; 129 } 130 } 131 132 /* set tv standard */ 133 if (ap->standard && !ioctl(video_fd, VIDIOCGTUNER, &tuner)) { 134 if (!strcasecmp(ap->standard, "pal")) 135 tuner.mode = VIDEO_MODE_PAL; 136 else if (!strcasecmp(ap->standard, "secam")) 137 tuner.mode = VIDEO_MODE_SECAM; 138 else 139 tuner.mode = VIDEO_MODE_NTSC; 140 ioctl(video_fd, VIDIOCSTUNER, &tuner); 141 } 142 143 /* unmute audio */ 144 audio.audio = 0; 145 ioctl(video_fd, VIDIOCGAUDIO, &audio); 146 memcpy(&s->audio_saved, &audio, sizeof(audio)); 147 audio.flags &= ~VIDEO_AUDIO_MUTE; 148 ioctl(video_fd, VIDIOCSAUDIO, &audio); 149 150 ioctl(video_fd, VIDIOCGPICT, &pict); 151#if 0 152 printf("v4l: colour=%d hue=%d brightness=%d constrast=%d whiteness=%d\n", 153 pict.colour, 154 pict.hue, 155 pict.brightness, 156 pict.contrast, 157 pict.whiteness); 158#endif 159 /* try to choose a suitable video format */ 160 pict.palette = desired_palette; 161 pict.depth= desired_depth; 162 if (desired_palette == -1 || ioctl(video_fd, VIDIOCSPICT, &pict) < 0) { 163 for (j = 0; j < vformat_num; j++) { 164 pict.palette = video_formats[j].palette; 165 pict.depth = video_formats[j].depth; 166 if (-1 != ioctl(video_fd, VIDIOCSPICT, &pict)) 167 break; 168 } 169 if (j >= vformat_num) 170 goto fail1; 171 } 172 173 if (ioctl(video_fd, VIDIOCGMBUF, &s->gb_buffers) < 0) { 174 /* try to use read based access */ 175 int val; 176 177 s->video_win.x = 0; 178 s->video_win.y = 0; 179 s->video_win.chromakey = -1; 180 s->video_win.flags = 0; 181 182 if (ioctl(video_fd, VIDIOCSWIN, s->video_win) < 0) { 183 av_log(s1, AV_LOG_ERROR, "VIDIOCSWIN: %s\n", strerror(errno)); 184 goto fail; 185 } 186 187 s->frame_format = pict.palette; 188 189 val = 1; 190 if (ioctl(video_fd, VIDIOCCAPTURE, &val) < 0) { 191 av_log(s1, AV_LOG_ERROR, "VIDIOCCAPTURE: %s\n", strerror(errno)); 192 goto fail; 193 } 194 195 s->time_frame = av_gettime() * s->time_base.den / s->time_base.num; 196 s->use_mmap = 0; 197 } else { 198 s->video_buf = mmap(0, s->gb_buffers.size, PROT_READ|PROT_WRITE, MAP_SHARED, video_fd, 0); 199 if ((unsigned char*)-1 == s->video_buf) { 200 s->video_buf = mmap(0, s->gb_buffers.size, PROT_READ|PROT_WRITE, MAP_PRIVATE, video_fd, 0); 201 if ((unsigned char*)-1 == s->video_buf) { 202 av_log(s1, AV_LOG_ERROR, "mmap: %s\n", strerror(errno)); 203 goto fail; 204 } 205 } 206 s->gb_frame = 0; 207 s->time_frame = av_gettime() * s->time_base.den / s->time_base.num; 208 209 /* start to grab the first frame */ 210 s->gb_buf.frame = s->gb_frame % s->gb_buffers.frames; 211 s->gb_buf.height = s->video_win.height; 212 s->gb_buf.width = s->video_win.width; 213 s->gb_buf.format = pict.palette; 214 215 if (ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) { 216 if (errno != EAGAIN) { 217 fail1: 218 av_log(s1, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno)); 219 } else { 220 av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not receive any video signal\n"); 221 } 222 goto fail; 223 } 224 for (j = 1; j < s->gb_buffers.frames; j++) { 225 s->gb_buf.frame = j; 226 ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf); 227 } 228 s->frame_format = s->gb_buf.format; 229 s->use_mmap = 1; 230 } 231 232 for (j = 0; j < vformat_num; j++) { 233 if (s->frame_format == video_formats[j].palette) { 234 s->frame_size = s->video_win.width * s->video_win.height * video_formats[j].depth / 8; 235 st->codec->pix_fmt = video_formats[j].pix_fmt; 236 break; 237 } 238 } 239 240 if (j >= vformat_num) 241 goto fail; 242 243 s->fd = video_fd; 244 245 st->codec->codec_type = CODEC_TYPE_VIDEO; 246 st->codec->codec_id = CODEC_ID_RAWVIDEO; 247 st->codec->width = s->video_win.width; 248 st->codec->height = s->video_win.height; 249 st->codec->time_base = s->time_base; 250 st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8; 251 252 return 0; 253 fail: 254 if (video_fd >= 0) 255 close(video_fd); 256 return AVERROR(EIO); 257} 258 259static int v4l_mm_read_picture(VideoData *s, uint8_t *buf) 260{ 261 uint8_t *ptr; 262 263 while (ioctl(s->fd, VIDIOCSYNC, &s->gb_frame) < 0 && 264 (errno == EAGAIN || errno == EINTR)); 265 266 ptr = s->video_buf + s->gb_buffers.offsets[s->gb_frame]; 267 memcpy(buf, ptr, s->frame_size); 268 269 /* Setup to capture the next frame */ 270 s->gb_buf.frame = s->gb_frame; 271 if (ioctl(s->fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) { 272 if (errno == EAGAIN) 273 av_log(NULL, AV_LOG_ERROR, "Cannot Sync\n"); 274 else 275 av_log(NULL, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno)); 276 return AVERROR(EIO); 277 } 278 279 /* This is now the grabbing frame */ 280 s->gb_frame = (s->gb_frame + 1) % s->gb_buffers.frames; 281 282 return s->frame_size; 283} 284 285static int grab_read_packet(AVFormatContext *s1, AVPacket *pkt) 286{ 287 VideoData *s = s1->priv_data; 288 int64_t curtime, delay; 289 struct timespec ts; 290 291 /* Calculate the time of the next frame */ 292 s->time_frame += INT64_C(1000000); 293 294 /* wait based on the frame rate */ 295 for(;;) { 296 curtime = av_gettime(); 297 delay = s->time_frame * s->time_base.num / s->time_base.den - curtime; 298 if (delay <= 0) { 299 if (delay < INT64_C(-1000000) * s->time_base.num / s->time_base.den) { 300 /* printf("grabbing is %d frames late (dropping)\n", (int) -(delay / 16666)); */ 301 s->time_frame += INT64_C(1000000); 302 } 303 break; 304 } 305 ts.tv_sec = delay / 1000000; 306 ts.tv_nsec = (delay % 1000000) * 1000; 307 nanosleep(&ts, NULL); 308 } 309 310 if (av_new_packet(pkt, s->frame_size) < 0) 311 return AVERROR(EIO); 312 313 pkt->pts = curtime; 314 315 /* read one frame */ 316 if (s->use_mmap) { 317 return v4l_mm_read_picture(s, pkt->data); 318 } else { 319 if (read(s->fd, pkt->data, pkt->size) != pkt->size) 320 return AVERROR(EIO); 321 return s->frame_size; 322 } 323} 324 325static int grab_read_close(AVFormatContext *s1) 326{ 327 VideoData *s = s1->priv_data; 328 329 if (s->use_mmap) 330 munmap(s->video_buf, s->gb_buffers.size); 331 332 /* mute audio. we must force it because the BTTV driver does not 333 return its state correctly */ 334 s->audio_saved.flags |= VIDEO_AUDIO_MUTE; 335 ioctl(s->fd, VIDIOCSAUDIO, &s->audio_saved); 336 337 close(s->fd); 338 return 0; 339} 340 341AVInputFormat v4l_demuxer = { 342 "video4linux", 343 NULL_IF_CONFIG_SMALL("Video4Linux device grab"), 344 sizeof(VideoData), 345 NULL, 346 grab_read_header, 347 grab_read_packet, 348 grab_read_close, 349 .flags = AVFMT_NOFILE, 350}; 351