ffmpeg/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 "avdevice.h"
  23
  24 #undef __STRICT_ANSI__ //workaround due to broken kernel headers
  25 #include "config.h"
  26 #include "libavutil/rational.h"
  27 #include "libavutil/imgutils.h"
  28 #include "libavutil/log.h"
  29 #include "libavutil/opt.h"
  30 #include "libavformat/internal.h"
  31 #include "libavcodec/dsputil.h"
  32 #include <unistd.h>
  33 #include <fcntl.h>
  34 #include <sys/ioctl.h>
  35 #include <sys/mman.h>
  36 #include <sys/time.h>
  37 #define _LINUX_TIME_H 1
  38 #include <linux/videodev.h>
  39 #include <time.h>
  40
  41 typedef struct {
  42     AVClass *class;
  43     int fd;
  44     int frame_format; /* see VIDEO_PALETTE_xxx */
  45     int use_mmap;
  46     AVRational time_base;
  47     int64_t time_frame;
  48     int frame_size;
  49     struct video_capability video_cap;
  50     struct video_audio audio_saved;
  51     struct video_window video_win;
  52     uint8_t *video_buf;
  53     struct video_mbuf gb_buffers;
  54     struct video_mmap gb_buf;
  55     int gb_frame;
  56     int standard;
  57 } VideoData;
  58
  59 static const struct {
  60     int palette;
  61     int depth;
  62     enum AVPixelFormat pix_fmt;
  63 } video_formats [] = {
  64     {.palette = VIDEO_PALETTE_YUV420P, .depth = 12, .pix_fmt = AV_PIX_FMT_YUV420P },
  65     {.palette = VIDEO_PALETTE_YUV422,  .depth = 16, .pix_fmt = AV_PIX_FMT_YUYV422 },
  66     {.palette = VIDEO_PALETTE_UYVY,    .depth = 16, .pix_fmt = AV_PIX_FMT_UYVY422 },
  67     {.palette = VIDEO_PALETTE_YUYV,    .depth = 16, .pix_fmt = AV_PIX_FMT_YUYV422 },
  68     /* NOTE: v4l uses BGR24, not RGB24 */
  69     {.palette = VIDEO_PALETTE_RGB24,   .depth = 24, .pix_fmt = AV_PIX_FMT_BGR24   },
  70     {.palette = VIDEO_PALETTE_RGB565,  .depth = 16, .pix_fmt = AV_PIX_FMT_BGR565  },
  71     {.palette = VIDEO_PALETTE_GREY,    .depth = 8,  .pix_fmt = AV_PIX_FMT_GRAY8   },
  72 };
  73
  74
  75 static int grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
  76 {
  77     VideoData *s = s1->priv_data;
  78     AVStream *st;
  79     int video_fd;
  80     int desired_palette, desired_depth;
  81     struct video_tuner tuner;
  82     struct video_audio audio;
  83     struct video_picture pict;
  84     int j;
  85     int vformat_num = FF_ARRAY_ELEMS(video_formats);
  86
  87     av_log(s1, AV_LOG_WARNING, "V4L input device is deprecated and will be removed in the next release.");
  88
  89     if (ap->time_base.den <= 0) {
  90         av_log(s1, AV_LOG_ERROR, "Wrong time base (%d)\n", ap->time_base.den);
  91         return -1;
  92     }
  93     s->time_base = ap->time_base;
  94
  95     s->video_win.width = ap->width;
  96     s->video_win.height = ap->height;
  97
  98     st = avformat_new_stream(s1, NULL);
  99     if (!st)
 100         return AVERROR(ENOMEM);
 101     avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
 102
 103     video_fd = open(s1->filename, O_RDWR);
 104     if (video_fd < 0) {
 105         av_log(s1, AV_LOG_ERROR, "%s: %s\n", s1->filename, strerror(errno));
 106         goto fail;
 107     }
 108
 109     if (ioctl(video_fd, VIDIOCGCAP, &s->video_cap) < 0) {
 110         av_log(s1, AV_LOG_ERROR, "VIDIOCGCAP: %s\n", strerror(errno));
 111         goto fail;
 112     }
 113
 114     if (!(s->video_cap.type & VID_TYPE_CAPTURE)) {
 115         av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not handle capture\n");
 116         goto fail;
 117     }
 118
 119     /* no values set, autodetect them */
 120     if (s->video_win.width <= 0 || s->video_win.height <= 0) {
 121         if (ioctl(video_fd, VIDIOCGWIN, &s->video_win, sizeof(s->video_win)) < 0) {
 122             av_log(s1, AV_LOG_ERROR, "VIDIOCGWIN: %s\n", strerror(errno));
 123             goto fail;
 124         }
 125     }
 126
 127     if(av_image_check_size(s->video_win.width, s->video_win.height, 0, s1) < 0)
 128         return -1;
 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 (!ioctl(video_fd, VIDIOCGTUNER, &tuner)) {
 142         tuner.mode = s->standard;
 143         ioctl(video_fd, VIDIOCSTUNER, &tuner);
 144     }
 145
 146     /* unmute audio */
 147     audio.audio = 0;
 148     ioctl(video_fd, VIDIOCGAUDIO, &audio);
 149     memcpy(&s->audio_saved, &audio, sizeof(audio));
 150     audio.flags &= ~VIDEO_AUDIO_MUTE;
 151     ioctl(video_fd, VIDIOCSAUDIO, &audio);
 152
 153     ioctl(video_fd, VIDIOCGPICT, &pict);
 154     av_dlog(s1, "v4l: colour=%d hue=%d brightness=%d constrast=%d whiteness=%d\n",
 155             pict.colour, pict.hue, pict.brightness, pict.contrast, pict.whiteness);
 156     /* try to choose a suitable video format */
 157     pict.palette = desired_palette;
 158     pict.depth= desired_depth;
 159     if (desired_palette == -1 || ioctl(video_fd, VIDIOCSPICT, &pict) < 0) {
 160         for (j = 0; j < vformat_num; j++) {
 161             pict.palette = video_formats[j].palette;
 162             pict.depth = video_formats[j].depth;
 163             if (-1 != ioctl(video_fd, VIDIOCSPICT, &pict))
 164                 break;
 165         }
 166         if (j >= vformat_num)
 167             goto fail1;
 168     }
 169
 170     if (ioctl(video_fd, VIDIOCGMBUF, &s->gb_buffers) < 0) {
 171         /* try to use read based access */
 172         int val;
 173
 174         s->video_win.x = 0;
 175         s->video_win.y = 0;
 176         s->video_win.chromakey = -1;
 177         s->video_win.flags = 0;
 178
 179         if (ioctl(video_fd, VIDIOCSWIN, s->video_win) < 0) {
 180             av_log(s1, AV_LOG_ERROR, "VIDIOCSWIN: %s\n", strerror(errno));
 181             goto fail;
 182         }
 183
 184         s->frame_format = pict.palette;
 185
 186         val = 1;
 187         if (ioctl(video_fd, VIDIOCCAPTURE, &val) < 0) {
 188             av_log(s1, AV_LOG_ERROR, "VIDIOCCAPTURE: %s\n", strerror(errno));
 189             goto fail;
 190         }
 191
 192         s->time_frame = av_gettime() * s->time_base.den / s->time_base.num;
 193         s->use_mmap = 0;
 194     } else {
 195         s->video_buf = mmap(0, s->gb_buffers.size, PROT_READ|PROT_WRITE, MAP_SHARED, video_fd, 0);
 196         if ((unsigned char*)-1 == s->video_buf) {
 197             s->video_buf = mmap(0, s->gb_buffers.size, PROT_READ|PROT_WRITE, MAP_PRIVATE, video_fd, 0);
 198             if ((unsigned char*)-1 == s->video_buf) {
 199                 av_log(s1, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
 200                 goto fail;
 201             }
 202         }
 203         s->gb_frame = 0;
 204         s->time_frame = av_gettime() * s->time_base.den / s->time_base.num;
 205
 206         /* start to grab the first frame */
 207         s->gb_buf.frame = s->gb_frame % s->gb_buffers.frames;
 208         s->gb_buf.height = s->video_win.height;
 209         s->gb_buf.width = s->video_win.width;
 210         s->gb_buf.format = pict.palette;
 211
 212         if (ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) {
 213             if (errno != EAGAIN) {
 214             fail1:
 215                 av_log(s1, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno));
 216             } else {
 217                 av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not receive any video signal\n");
 218             }
 219             goto fail;
 220         }
 221         for (j = 1; j < s->gb_buffers.frames; j++) {
 222           s->gb_buf.frame = j;
 223           ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf);
 224         }
 225         s->frame_format = s->gb_buf.format;
 226         s->use_mmap = 1;
 227     }
 228
 229     for (j = 0; j < vformat_num; j++) {
 230         if (s->frame_format == video_formats[j].palette) {
 231             s->frame_size = s->video_win.width * s->video_win.height * video_formats[j].depth / 8;
 232             st->codec->pix_fmt = video_formats[j].pix_fmt;
 233             break;
 234         }
 235     }
 236
 237     if (j >= vformat_num)
 238         goto fail;
 239
 240     s->fd = video_fd;
 241
 242     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
 243     st->codec->codec_id = AV_CODEC_ID_RAWVIDEO;
 244     st->codec->width = s->video_win.width;
 245     st->codec->height = s->video_win.height;
 246     st->codec->time_base = s->time_base;
 247     st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;
 248
 249     return 0;
 250  fail:
 251     if (video_fd >= 0)
 252         close(video_fd);
 253     return AVERROR(EIO);
 254 }
 255
 256 static int v4l_mm_read_picture(VideoData *s, uint8_t *buf)
 257 {
 258     uint8_t *ptr;
 259
 260     while (ioctl(s->fd, VIDIOCSYNC, &s->gb_frame) < 0 &&
 261            (errno == EAGAIN || errno == EINTR));
 262
 263     ptr = s->video_buf + s->gb_buffers.offsets[s->gb_frame];
 264     memcpy(buf, ptr, s->frame_size);
 265
 266     /* Setup to capture the next frame */
 267     s->gb_buf.frame = s->gb_frame;
 268     if (ioctl(s->fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) {
 269         if (errno == EAGAIN)
 270             av_log(NULL, AV_LOG_ERROR, "Cannot Sync\n");
 271         else
 272             av_log(NULL, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno));
 273         return AVERROR(EIO);
 274     }
 275
 276     /* This is now the grabbing frame */
 277     s->gb_frame = (s->gb_frame + 1) % s->gb_buffers.frames;
 278
 279     return s->frame_size;
 280 }
 281
 282 static int grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
 283 {
 284     VideoData *s = s1->priv_data;
 285     int64_t curtime, delay;
 286     struct timespec ts;
 287
 288     /* Calculate the time of the next frame */
 289     s->time_frame += INT64_C(1000000);
 290
 291     /* wait based on the frame rate */
 292     for(;;) {
 293         curtime = av_gettime();
 294         delay = s->time_frame * s->time_base.num / s->time_base.den - curtime;
 295         if (delay <= 0) {
 296             if (delay < INT64_C(-1000000) * s->time_base.num / s->time_base.den) {
 297                 /* printf("grabbing is %d frames late (dropping)\n", (int) -(delay / 16666)); */
 298                 s->time_frame += INT64_C(1000000);
 299             }
 300             break;
 301         }
 302         ts.tv_sec = delay / 1000000;
 303         ts.tv_nsec = (delay % 1000000) * 1000;
 304         nanosleep(&ts, NULL);
 305     }
 306
 307     if (av_new_packet(pkt, s->frame_size) < 0)
 308         return AVERROR(EIO);
 309
 310     pkt->pts = curtime;
 311
 312     /* read one frame */
 313     if (s->use_mmap) {
 314         return v4l_mm_read_picture(s, pkt->data);
 315     } else {
 316         if (read(s->fd, pkt->data, pkt->size) != pkt->size)
 317             return AVERROR(EIO);
 318         return s->frame_size;
 319     }
 320 }
 321
 322 static int grab_read_close(AVFormatContext *s1)
 323 {
 324     VideoData *s = s1->priv_data;
 325
 326     if (s->use_mmap)
 327         munmap(s->video_buf, s->gb_buffers.size);
 328
 329     /* mute audio. we must force it because the BTTV driver does not
 330        return its state correctly */
 331     s->audio_saved.flags |= VIDEO_AUDIO_MUTE;
 332     ioctl(s->fd, VIDIOCSAUDIO, &s->audio_saved);
 333
 334     close(s->fd);
 335     return 0;
 336 }
 337
 338 static const AVOption options[] = {
 339     { "standard", "", offsetof(VideoData, standard), AV_OPT_TYPE_INT, {.i64 = VIDEO_MODE_NTSC}, VIDEO_MODE_PAL, VIDEO_MODE_NTSC, AV_OPT_FLAG_DECODING_PARAM, "standard" },
 340     { "PAL",   "", 0, AV_OPT_TYPE_CONST, {.i64 = VIDEO_MODE_PAL},   0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
 341     { "SECAM", "", 0, AV_OPT_TYPE_CONST, {.i64 = VIDEO_MODE_SECAM}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
 342     { "NTSC",  "", 0, AV_OPT_TYPE_CONST, {.i64 = VIDEO_MODE_NTSC},  0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
 343     { NULL },
 344 };
 345
 346 static const AVClass v4l_class = {
 347     .class_name = "V4L indev",
 348     .item_name  = av_default_item_name,
 349     .option     = options,
 350     .version    = LIBAVUTIL_VERSION_INT,
 351     .category   = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
 352 };
 353
 354 AVInputFormat ff_v4l_demuxer = {
 355     .name           = "video4linux,v4l",
 356     .long_name      = NULL_IF_CONFIG_SMALL("Video4Linux device grab"),
 357     .priv_data_size = sizeof(VideoData),
 358     .read_header    = grab_read_header,
 359     .read_packet    = grab_read_packet,
 360     .read_close     = grab_read_close,
 361     .flags          = AVFMT_NOFILE,
 362     .priv_class     = &v4l_class,
 363 };