libavdevice/v4l.c

   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 #include "config.h"
  23 #include "libavformat/avformat.h"
  24 #include "libavcodec/dsputil.h"
  25 #include <unistd.h>
  26 #include <fcntl.h>
  27 #include <sys/ioctl.h>
  28 #include <sys/mman.h>
  29 #include <sys/time.h>
  30 #define _LINUX_TIME_H 1
  31 #include <linux/videodev.h>
  32 #include <time.h>
  33
  34 typedef struct {
  35     int fd;
  36     int frame_format; /* see VIDEO_PALETTE_xxx */
  37     int use_mmap;
  38     int width, height;
  39     int frame_rate;
  40     int frame_rate_base;
  41     int64_t time_frame;
  42     int frame_size;
  43     struct video_capability video_cap;
  44     struct video_audio audio_saved;
  45     uint8_t *video_buf;
  46     struct video_mbuf gb_buffers;
  47     struct video_mmap gb_buf;
  48     int gb_frame;
  49 } VideoData;
  50
  51 static const struct {
  52     int palette;
  53     int depth;
  54     enum PixelFormat pix_fmt;
  55 } video_formats [] = {
  56     {.palette = VIDEO_PALETTE_YUV420P, .depth = 12, .pix_fmt = PIX_FMT_YUV420P },
  57     {.palette = VIDEO_PALETTE_YUV422,  .depth = 16, .pix_fmt = PIX_FMT_YUYV422 },
  58     {.palette = VIDEO_PALETTE_UYVY,    .depth = 16, .pix_fmt = PIX_FMT_UYVY422 },
  59     {.palette = VIDEO_PALETTE_YUYV,    .depth = 16, .pix_fmt = PIX_FMT_YUYV422 },
  60     /* NOTE: v4l uses BGR24, not RGB24 */
  61     {.palette = VIDEO_PALETTE_RGB24,   .depth = 24, .pix_fmt = PIX_FMT_BGR24   },
  62     {.palette = VIDEO_PALETTE_RGB565,  .depth = 16, .pix_fmt = PIX_FMT_BGR565  },
  63     {.palette = VIDEO_PALETTE_GREY,    .depth = 8,  .pix_fmt = PIX_FMT_GRAY8   },
  64 };
  65
  66
  67 static int grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
  68 {
  69     VideoData *s = s1->priv_data;
  70     AVStream *st;
  71     int width, height;
  72     int video_fd, frame_size;
  73     int ret, frame_rate, frame_rate_base;
  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 = sizeof(video_formats) / sizeof(video_formats[0]);
  80
  81     if (ap->width <= 0 || ap->height <= 0 || ap->time_base.den <= 0) {
  82         av_log(s1, AV_LOG_ERROR, "Bad capture size (%dx%d) or wrong time base (%d)\n",
  83             ap->width, ap->height, ap->time_base.den);
  84
  85         return -1;
  86     }
  87
  88     width = ap->width;
  89     height = ap->height;
  90     frame_rate      = ap->time_base.den;
  91     frame_rate_base = ap->time_base.num;
  92
  93     if((unsigned)width > 32767 || (unsigned)height > 32767) {
  94         av_log(s1, AV_LOG_ERROR, "Capture size is out of range: %dx%d\n",
  95             width, height);
  96
  97         return -1;
  98     }
  99
 100     st = av_new_stream(s1, 0);
 101     if (!st)
 102         return AVERROR(ENOMEM);
 103     av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
 104
 105     s->width = width;
 106     s->height = height;
 107     s->frame_rate      = frame_rate;
 108     s->frame_rate_base = frame_rate_base;
 109
 110     video_fd = open(s1->filename, O_RDWR);
 111     if (video_fd < 0) {
 112         av_log(s1, AV_LOG_ERROR, "%s: %s\n", s1->filename, strerror(errno));
 113         goto fail;
 114     }
 115
 116     if (ioctl(video_fd,VIDIOCGCAP, &s->video_cap) < 0) {
 117         av_log(s1, AV_LOG_ERROR, "VIDIOCGCAP: %s\n", strerror(errno));
 118         goto fail;
 119     }
 120
 121     if (!(s->video_cap.type & VID_TYPE_CAPTURE)) {
 122         av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not handle capture\n");
 123         goto fail;
 124     }
 125
 126     desired_palette = -1;
 127     desired_depth = -1;
 128     for (j = 0; j < vformat_num; j++) {
 129         if (ap->pix_fmt == video_formats[j].pix_fmt) {
 130             desired_palette = video_formats[j].palette;
 131             desired_depth = video_formats[j].depth;
 132             break;
 133         }
 134     }
 135
 136     /* set tv standard */
 137     if (ap->standard && !ioctl(video_fd, VIDIOCGTUNER, &tuner)) {
 138         if (!strcasecmp(ap->standard, "pal"))
 139             tuner.mode = VIDEO_MODE_PAL;
 140         else if (!strcasecmp(ap->standard, "secam"))
 141             tuner.mode = VIDEO_MODE_SECAM;
 142         else
 143             tuner.mode = VIDEO_MODE_NTSC;
 144         ioctl(video_fd, VIDIOCSTUNER, &tuner);
 145     }
 146
 147     /* unmute audio */
 148     audio.audio = 0;
 149     ioctl(video_fd, VIDIOCGAUDIO, &audio);
 150     memcpy(&s->audio_saved, &audio, sizeof(audio));
 151     audio.flags &= ~VIDEO_AUDIO_MUTE;
 152     ioctl(video_fd, VIDIOCSAUDIO, &audio);
 153
 154     ioctl(video_fd, VIDIOCGPICT, &pict);
 155 #if 0
 156     printf("v4l: colour=%d hue=%d brightness=%d constrast=%d whiteness=%d\n",
 157            pict.colour,
 158            pict.hue,
 159            pict.brightness,
 160            pict.contrast,
 161            pict.whiteness);
 162 #endif
 163     /* try to choose a suitable video format */
 164     pict.palette = desired_palette;
 165     pict.depth= desired_depth;
 166     if (desired_palette == -1 || (ret = ioctl(video_fd, VIDIOCSPICT, &pict)) < 0) {
 167         for (j = 0; j < vformat_num; j++) {
 168             pict.palette = video_formats[j].palette;
 169             pict.depth = video_formats[j].depth;
 170             if (-1 != ioctl(video_fd, VIDIOCSPICT, &pict))
 171                 break;
 172         }
 173         if (j >= vformat_num)
 174             goto fail1;
 175     }
 176
 177     ret = ioctl(video_fd,VIDIOCGMBUF,&s->gb_buffers);
 178     if (ret < 0) {
 179         /* try to use read based access */
 180         struct video_window win;
 181         int val;
 182
 183         win.x = 0;
 184         win.y = 0;
 185         win.width = width;
 186         win.height = height;
 187         win.chromakey = -1;
 188         win.flags = 0;
 189
 190         ioctl(video_fd, VIDIOCSWIN, &win);
 191
 192         s->frame_format = pict.palette;
 193
 194         val = 1;
 195         ioctl(video_fd, VIDIOCCAPTURE, &val);
 196
 197         s->time_frame = av_gettime() * s->frame_rate / s->frame_rate_base;
 198         s->use_mmap = 0;
 199     } else {
 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));
 205                 goto fail;
 206             }
 207         }
 208         s->gb_frame = 0;
 209         s->time_frame = av_gettime() * s->frame_rate / s->frame_rate_base;
 210
 211         /* start to grab the first frame */
 212         s->gb_buf.frame = s->gb_frame % s->gb_buffers.frames;
 213         s->gb_buf.height = height;
 214         s->gb_buf.width = width;
 215         s->gb_buf.format = pict.palette;
 216
 217         ret = ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf);
 218         if (ret < 0) {
 219             if (errno != EAGAIN) {
 220             fail1:
 221                 av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not support suitable format\n");
 222             } else {
 223                 av_log(s1, AV_LOG_ERROR,"Fatal: grab device does not receive any video signal\n");
 224             }
 225             goto fail;
 226         }
 227         for (j = 1; j < s->gb_buffers.frames; j++) {
 228           s->gb_buf.frame = j;
 229           ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf);
 230         }
 231         s->frame_format = s->gb_buf.format;
 232         s->use_mmap = 1;
 233     }
 234
 235     for (j = 0; j < vformat_num; j++) {
 236         if (s->frame_format == video_formats[j].palette) {
 237             frame_size = width * height * video_formats[j].depth / 8;
 238             st->codec->pix_fmt = video_formats[j].pix_fmt;
 239             break;
 240         }
 241     }
 242
 243     if (j >= vformat_num)
 244         goto fail;
 245
 246     s->fd = video_fd;
 247     s->frame_size = frame_size;
 248
 249     st->codec->codec_type = CODEC_TYPE_VIDEO;
 250     st->codec->codec_id = CODEC_ID_RAWVIDEO;
 251     st->codec->width = width;
 252     st->codec->height = height;
 253     st->codec->time_base.den      = frame_rate;
 254     st->codec->time_base.num = frame_rate_base;
 255     st->codec->bit_rate = frame_size * 1/av_q2d(st->codec->time_base) * 8;
 256
 257     return 0;
 258  fail:
 259     if (video_fd >= 0)
 260         close(video_fd);
 261     av_free(st);
 262     return AVERROR(EIO);
 263 }
 264
 265 static int v4l_mm_read_picture(VideoData *s, uint8_t *buf)
 266 {
 267     uint8_t *ptr;
 268
 269     while (ioctl(s->fd, VIDIOCSYNC, &s->gb_frame) < 0 &&
 270            (errno == EAGAIN || errno == EINTR));
 271
 272     ptr = s->video_buf + s->gb_buffers.offsets[s->gb_frame];
 273     memcpy(buf, ptr, s->frame_size);
 274
 275     /* Setup to capture the next frame */
 276     s->gb_buf.frame = s->gb_frame;
 277     if (ioctl(s->fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) {
 278         if (errno == EAGAIN)
 279             av_log(NULL, AV_LOG_ERROR, "Cannot Sync\n");
 280         else
 281             av_log(NULL, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno));
 282         return AVERROR(EIO);
 283     }
 284
 285     /* This is now the grabbing frame */
 286     s->gb_frame = (s->gb_frame + 1) % s->gb_buffers.frames;
 287
 288     return s->frame_size;
 289 }
 290
 291 static int grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
 292 {
 293     VideoData *s = s1->priv_data;
 294     int64_t curtime, delay;
 295     struct timespec ts;
 296
 297     /* Calculate the time of the next frame */
 298     s->time_frame += INT64_C(1000000);
 299
 300     /* wait based on the frame rate */
 301     for(;;) {
 302         curtime = av_gettime();
 303         delay = s->time_frame  * s->frame_rate_base / s->frame_rate - curtime;
 304         if (delay <= 0) {
 305             if (delay < INT64_C(-1000000) * s->frame_rate_base / s->frame_rate) {
 306                 /* printf("grabbing is %d frames late (dropping)\n", (int) -(delay / 16666)); */
 307                 s->time_frame += INT64_C(1000000);
 308             }
 309             break;
 310         }
 311         ts.tv_sec = delay / 1000000;
 312         ts.tv_nsec = (delay % 1000000) * 1000;
 313         nanosleep(&ts, NULL);
 314     }
 315
 316     if (av_new_packet(pkt, s->frame_size) < 0)
 317         return AVERROR(EIO);
 318
 319     pkt->pts = curtime;
 320
 321     /* read one frame */
 322     if (s->use_mmap) {
 323         return v4l_mm_read_picture(s, pkt->data);
 324     } else {
 325         if (read(s->fd, pkt->data, pkt->size) != pkt->size)
 326             return AVERROR(EIO);
 327         return s->frame_size;
 328     }
 329 }
 330
 331 static int grab_read_close(AVFormatContext *s1)
 332 {
 333     VideoData *s = s1->priv_data;
 334
 335     if (s->use_mmap)
 336         munmap(s->video_buf, s->gb_buffers.size);
 337
 338     /* mute audio. we must force it because the BTTV driver does not
 339        return its state correctly */
 340     s->audio_saved.flags |= VIDEO_AUDIO_MUTE;
 341     ioctl(s->fd, VIDIOCSAUDIO, &s->audio_saved);
 342
 343     close(s->fd);
 344     return 0;
 345 }
 346
 347 AVInputFormat v4l_demuxer = {
 348     "video4linux",
 349     NULL_IF_CONFIG_SMALL("video grab"),
 350     sizeof(VideoData),
 351     NULL,
 352     grab_read_header,
 353     grab_read_packet,
 354     grab_read_close,
 355     .flags = AVFMT_NOFILE,
 356 };