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 #undef __STRICT_ANSI__ //workaround due to broken kernel headers
  23 #include "config.h"
  24 #include "libavformat/avformat.h"
  25 #include "libavcodec/dsputil.h"
  26 #include <unistd.h>
  27 #include <fcntl.h>
  28 #include <sys/ioctl.h>
  29 #include <sys/mman.h>
  30 #include <sys/time.h>
  31 #define _LINUX_TIME_H 1
  32 #include <linux/videodev.h>
  33 #include <time.h>
  34 #include <strings.h>
  35
  36 typedef struct {
  37     int fd;
  38     int frame_format; /* see VIDEO_PALETTE_xxx */
  39     int use_mmap;
  40     int width, height;
  41     int frame_rate;
  42     int frame_rate_base;
  43     int64_t time_frame;
  44     int frame_size;
  45     struct video_capability video_cap;
  46     struct video_audio audio_saved;
  47     uint8_t *video_buf;
  48     struct video_mbuf gb_buffers;
  49     struct video_mmap gb_buf;
  50     int gb_frame;
  51 } VideoData;
  52
  53 static 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
  69 static int grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
  70 {
  71     VideoData *s = s1->priv_data;
  72     AVStream *st;
  73     int width, height;
  74     int video_fd, frame_size;
  75     int ret, frame_rate, frame_rate_base;
  76     int desired_palette, desired_depth;
  77     struct video_tuner tuner;
  78     struct video_audio audio;
  79     struct video_picture pict;
  80     int j;
  81     int vformat_num = sizeof(video_formats) / sizeof(video_formats[0]);
  82
  83     if (ap->width <= 0 || ap->height <= 0) {
  84         av_log(s1, AV_LOG_ERROR, "Wrong size (%dx%d)\n", ap->width, ap->height);
  85         return -1;
  86     }
  87     if (ap->time_base.den <= 0) {
  88         av_log(s1, AV_LOG_ERROR, "Wrong time base (%d)\n", ap->time_base.den);
  89         return -1;
  90     }
  91
  92     width = ap->width;
  93     height = ap->height;
  94     frame_rate      = ap->time_base.den;
  95     frame_rate_base = ap->time_base.num;
  96
  97     if((unsigned)width > 32767 || (unsigned)height > 32767) {
  98         av_log(s1, AV_LOG_ERROR, "Capture size is out of range: %dx%d\n",
  99             width, height);
 100
 101         return -1;
 102     }
 103
 104     st = av_new_stream(s1, 0);
 105     if (!st)
 106         return AVERROR(ENOMEM);
 107     av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
 108
 109     s->width = width;
 110     s->height = height;
 111     s->frame_rate      = frame_rate;
 112     s->frame_rate_base = frame_rate_base;
 113
 114     video_fd = open(s1->filename, O_RDWR);
 115     if (video_fd < 0) {
 116         av_log(s1, AV_LOG_ERROR, "%s: %s\n", s1->filename, strerror(errno));
 117         goto fail;
 118     }
 119
 120     if (ioctl(video_fd,VIDIOCGCAP, &s->video_cap) < 0) {
 121         av_log(s1, AV_LOG_ERROR, "VIDIOCGCAP: %s\n", strerror(errno));
 122         goto fail;
 123     }
 124
 125     if (!(s->video_cap.type & VID_TYPE_CAPTURE)) {
 126         av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not handle capture\n");
 127         goto fail;
 128     }
 129
 130     desired_palette = -1;
 131     desired_depth = -1;
 132     for (j = 0; j < vformat_num; j++) {
 133         if (ap->pix_fmt == video_formats[j].pix_fmt) {
 134             desired_palette = video_formats[j].palette;
 135             desired_depth = video_formats[j].depth;
 136             break;
 137         }
 138     }
 139
 140     /* set tv standard */
 141     if (ap->standard && !ioctl(video_fd, VIDIOCGTUNER, &tuner)) {
 142         if (!strcasecmp(ap->standard, "pal"))
 143             tuner.mode = VIDEO_MODE_PAL;
 144         else if (!strcasecmp(ap->standard, "secam"))
 145             tuner.mode = VIDEO_MODE_SECAM;
 146         else
 147             tuner.mode = VIDEO_MODE_NTSC;
 148         ioctl(video_fd, VIDIOCSTUNER, &tuner);
 149     }
 150
 151     /* unmute audio */
 152     audio.audio = 0;
 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);
 157
 158     ioctl(video_fd, VIDIOCGPICT, &pict);
 159 #if 0
 160     printf("v4l: colour=%d hue=%d brightness=%d constrast=%d whiteness=%d\n",
 161            pict.colour,
 162            pict.hue,
 163            pict.brightness,
 164            pict.contrast,
 165            pict.whiteness);
 166 #endif
 167     /* try to choose a suitable video format */
 168     pict.palette = desired_palette;
 169     pict.depth= desired_depth;
 170     if (desired_palette == -1 || (ret = ioctl(video_fd, VIDIOCSPICT, &pict)) < 0) {
 171         for (j = 0; j < vformat_num; j++) {
 172             pict.palette = video_formats[j].palette;
 173             pict.depth = video_formats[j].depth;
 174             if (-1 != ioctl(video_fd, VIDIOCSPICT, &pict))
 175                 break;
 176         }
 177         if (j >= vformat_num)
 178             goto fail1;
 179     }
 180
 181     ret = ioctl(video_fd,VIDIOCGMBUF,&s->gb_buffers);
 182     if (ret < 0) {
 183         /* try to use read based access */
 184         struct video_window win;
 185         int val;
 186
 187         win.x = 0;
 188         win.y = 0;
 189         win.width = width;
 190         win.height = height;
 191         win.chromakey = -1;
 192         win.flags = 0;
 193
 194         ioctl(video_fd, VIDIOCSWIN, &win);
 195
 196         s->frame_format = pict.palette;
 197
 198         val = 1;
 199         ioctl(video_fd, VIDIOCCAPTURE, &val);
 200
 201         s->time_frame = av_gettime() * s->frame_rate / s->frame_rate_base;
 202         s->use_mmap = 0;
 203     } else {
 204         s->video_buf = mmap(0,s->gb_buffers.size,PROT_READ|PROT_WRITE,MAP_SHARED,video_fd,0);
 205         if ((unsigned char*)-1 == s->video_buf) {
 206             s->video_buf = mmap(0,s->gb_buffers.size,PROT_READ|PROT_WRITE,MAP_PRIVATE,video_fd,0);
 207             if ((unsigned char*)-1 == s->video_buf) {
 208                 av_log(s1, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
 209                 goto fail;
 210             }
 211         }
 212         s->gb_frame = 0;
 213         s->time_frame = av_gettime() * s->frame_rate / s->frame_rate_base;
 214
 215         /* start to grab the first frame */
 216         s->gb_buf.frame = s->gb_frame % s->gb_buffers.frames;
 217         s->gb_buf.height = height;
 218         s->gb_buf.width = width;
 219         s->gb_buf.format = pict.palette;
 220
 221         ret = ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf);
 222         if (ret < 0) {
 223             if (errno != EAGAIN) {
 224             fail1:
 225                 av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not support suitable format\n");
 226             } else {
 227                 av_log(s1, AV_LOG_ERROR,"Fatal: grab device does not receive any video signal\n");
 228             }
 229             goto fail;
 230         }
 231         for (j = 1; j < s->gb_buffers.frames; j++) {
 232           s->gb_buf.frame = j;
 233           ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf);
 234         }
 235         s->frame_format = s->gb_buf.format;
 236         s->use_mmap = 1;
 237     }
 238
 239     for (j = 0; j < vformat_num; j++) {
 240         if (s->frame_format == video_formats[j].palette) {
 241             frame_size = width * height * video_formats[j].depth / 8;
 242             st->codec->pix_fmt = video_formats[j].pix_fmt;
 243             break;
 244         }
 245     }
 246
 247     if (j >= vformat_num)
 248         goto fail;
 249
 250     s->fd = video_fd;
 251     s->frame_size = frame_size;
 252
 253     st->codec->codec_type = CODEC_TYPE_VIDEO;
 254     st->codec->codec_id = CODEC_ID_RAWVIDEO;
 255     st->codec->width = width;
 256     st->codec->height = height;
 257     st->codec->time_base.den      = frame_rate;
 258     st->codec->time_base.num = frame_rate_base;
 259     st->codec->bit_rate = frame_size * 1/av_q2d(st->codec->time_base) * 8;
 260
 261     return 0;
 262  fail:
 263     if (video_fd >= 0)
 264         close(video_fd);
 265     return AVERROR(EIO);
 266 }
 267
 268 static int v4l_mm_read_picture(VideoData *s, uint8_t *buf)
 269 {
 270     uint8_t *ptr;
 271
 272     while (ioctl(s->fd, VIDIOCSYNC, &s->gb_frame) < 0 &&
 273            (errno == EAGAIN || errno == EINTR));
 274
 275     ptr = s->video_buf + s->gb_buffers.offsets[s->gb_frame];
 276     memcpy(buf, ptr, s->frame_size);
 277
 278     /* Setup to capture the next frame */
 279     s->gb_buf.frame = s->gb_frame;
 280     if (ioctl(s->fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) {
 281         if (errno == EAGAIN)
 282             av_log(NULL, AV_LOG_ERROR, "Cannot Sync\n");
 283         else
 284             av_log(NULL, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno));
 285         return AVERROR(EIO);
 286     }
 287
 288     /* This is now the grabbing frame */
 289     s->gb_frame = (s->gb_frame + 1) % s->gb_buffers.frames;
 290
 291     return s->frame_size;
 292 }
 293
 294 static int grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
 295 {
 296     VideoData *s = s1->priv_data;
 297     int64_t curtime, delay;
 298     struct timespec ts;
 299
 300     /* Calculate the time of the next frame */
 301     s->time_frame += INT64_C(1000000);
 302
 303     /* wait based on the frame rate */
 304     for(;;) {
 305         curtime = av_gettime();
 306         delay = s->time_frame  * s->frame_rate_base / s->frame_rate - curtime;
 307         if (delay <= 0) {
 308             if (delay < INT64_C(-1000000) * s->frame_rate_base / s->frame_rate) {
 309                 /* printf("grabbing is %d frames late (dropping)\n", (int) -(delay / 16666)); */
 310                 s->time_frame += INT64_C(1000000);
 311             }
 312             break;
 313         }
 314         ts.tv_sec = delay / 1000000;
 315         ts.tv_nsec = (delay % 1000000) * 1000;
 316         nanosleep(&ts, NULL);
 317     }
 318
 319     if (av_new_packet(pkt, s->frame_size) < 0)
 320         return AVERROR(EIO);
 321
 322     pkt->pts = curtime;
 323
 324     /* read one frame */
 325     if (s->use_mmap) {
 326         return v4l_mm_read_picture(s, pkt->data);
 327     } else {
 328         if (read(s->fd, pkt->data, pkt->size) != pkt->size)
 329             return AVERROR(EIO);
 330         return s->frame_size;
 331     }
 332 }
 333
 334 static int grab_read_close(AVFormatContext *s1)
 335 {
 336     VideoData *s = s1->priv_data;
 337
 338     if (s->use_mmap)
 339         munmap(s->video_buf, s->gb_buffers.size);
 340
 341     /* mute audio. we must force it because the BTTV driver does not
 342        return its state correctly */
 343     s->audio_saved.flags |= VIDEO_AUDIO_MUTE;
 344     ioctl(s->fd, VIDIOCSAUDIO, &s->audio_saved);
 345
 346     close(s->fd);
 347     return 0;
 348 }
 349
 350 AVInputFormat v4l_demuxer = {
 351     "video4linux",
 352     NULL_IF_CONFIG_SMALL("video grab"),
 353     sizeof(VideoData),
 354     NULL,
 355     grab_read_header,
 356     grab_read_packet,
 357     grab_read_close,
 358     .flags = AVFMT_NOFILE,
 359 };