libavdevice/dv1394.c

   1 /*
   2  * Linux DV1394 interface
   3  * Copyright (c) 2003 Max Krasnyansky <maxk@qualcomm.com>
   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 <unistd.h>
  24 #include <fcntl.h>
  25 #include <errno.h>
  26 #include <sys/ioctl.h>
  27 #include <sys/mman.h>
  28 #include <sys/poll.h>
  29 #include <sys/time.h>
  30 #include <time.h>
  31
  32 #include "libavformat/avformat.h"
  33
  34 #undef DV1394_DEBUG
  35
  36 #include "libavformat/dv.h"
  37 #include "dv1394.h"
  38
  39 struct dv1394_data {
  40     int fd;
  41     int channel;
  42     int format;
  43
  44     uint8_t *ring; /* Ring buffer */
  45     int index;  /* Current frame index */
  46     int avail;  /* Number of frames available for reading */
  47     int done;   /* Number of completed frames */
  48
  49     DVDemuxContext* dv_demux; /* Generic DV muxing/demuxing context */
  50 };
  51
  52 /*
  53  * The trick here is to kludge around well known problem with kernel Ooopsing
  54  * when you try to capture PAL on a device node configure for NTSC. That's
  55  * why we have to configure the device node for PAL, and then read only NTSC
  56  * amount of data.
  57  */
  58 static int dv1394_reset(struct dv1394_data *dv)
  59 {
  60     struct dv1394_init init;
  61
  62     init.channel     = dv->channel;
  63     init.api_version = DV1394_API_VERSION;
  64     init.n_frames    = DV1394_RING_FRAMES;
  65     init.format      = DV1394_PAL;
  66
  67     if (ioctl(dv->fd, DV1394_INIT, &init) < 0)
  68         return -1;
  69
  70     dv->avail  = dv->done = 0;
  71     return 0;
  72 }
  73
  74 static int dv1394_start(struct dv1394_data *dv)
  75 {
  76     /* Tell DV1394 driver to enable receiver */
  77     if (ioctl(dv->fd, DV1394_START_RECEIVE, 0) < 0) {
  78         av_log(NULL, AV_LOG_ERROR, "Failed to start receiver: %s\n", strerror(errno));
  79         return -1;
  80     }
  81     return 0;
  82 }
  83
  84 static int dv1394_read_header(AVFormatContext * context, AVFormatParameters * ap)
  85 {
  86     struct dv1394_data *dv = context->priv_data;
  87
  88     dv->dv_demux = dv_init_demux(context);
  89     if (!dv->dv_demux)
  90         goto failed;
  91
  92     if (ap->standard && !strcasecmp(ap->standard, "pal"))
  93         dv->format = DV1394_PAL;
  94     else
  95         dv->format = DV1394_NTSC;
  96
  97     if (ap->channel)
  98         dv->channel = ap->channel;
  99     else
 100         dv->channel = DV1394_DEFAULT_CHANNEL;
 101
 102     /* Open and initialize DV1394 device */
 103     dv->fd = open(context->filename, O_RDONLY);
 104     if (dv->fd < 0) {
 105         av_log(context, AV_LOG_ERROR, "Failed to open DV interface: %s\n", strerror(errno));
 106         goto failed;
 107     }
 108
 109     if (dv1394_reset(dv) < 0) {
 110         av_log(context, AV_LOG_ERROR, "Failed to initialize DV interface: %s\n", strerror(errno));
 111         goto failed;
 112     }
 113
 114     dv->ring = mmap(NULL, DV1394_PAL_FRAME_SIZE * DV1394_RING_FRAMES,
 115                     PROT_READ, MAP_PRIVATE, dv->fd, 0);
 116     if (dv->ring == MAP_FAILED) {
 117         av_log(context, AV_LOG_ERROR, "Failed to mmap DV ring buffer: %s\n", strerror(errno));
 118         goto failed;
 119     }
 120
 121     if (dv1394_start(dv) < 0)
 122         goto failed;
 123
 124     return 0;
 125
 126 failed:
 127     close(dv->fd);
 128     return AVERROR(EIO);
 129 }
 130
 131 static int dv1394_read_packet(AVFormatContext *context, AVPacket *pkt)
 132 {
 133     struct dv1394_data *dv = context->priv_data;
 134     int size;
 135
 136     size = dv_get_packet(dv->dv_demux, pkt);
 137     if (size > 0)
 138         return size;
 139
 140     if (!dv->avail) {
 141         struct dv1394_status s;
 142         struct pollfd p;
 143
 144         if (dv->done) {
 145             /* Request more frames */
 146             if (ioctl(dv->fd, DV1394_RECEIVE_FRAMES, dv->done) < 0) {
 147                 /* This usually means that ring buffer overflowed.
 148                  * We have to reset :(.
 149                  */
 150
 151                 av_log(context, AV_LOG_ERROR, "DV1394: Ring buffer overflow. Reseting ..\n");
 152
 153                 dv1394_reset(dv);
 154                 dv1394_start(dv);
 155             }
 156             dv->done = 0;
 157         }
 158
 159         /* Wait until more frames are available */
 160 restart_poll:
 161         p.fd = dv->fd;
 162         p.events = POLLIN | POLLERR | POLLHUP;
 163         if (poll(&p, 1, -1) < 0) {
 164             if (errno == EAGAIN || errno == EINTR)
 165                 goto restart_poll;
 166             av_log(context, AV_LOG_ERROR, "Poll failed: %s\n", strerror(errno));
 167             return AVERROR(EIO);
 168         }
 169
 170         if (ioctl(dv->fd, DV1394_GET_STATUS, &s) < 0) {
 171             av_log(context, AV_LOG_ERROR, "Failed to get status: %s\n", strerror(errno));
 172             return AVERROR(EIO);
 173         }
 174 #ifdef DV1394_DEBUG
 175         av_log(context, AV_LOG_DEBUG, "DV1394: status\n"
 176                 "\tactive_frame\t%d\n"
 177                 "\tfirst_clear_frame\t%d\n"
 178                 "\tn_clear_frames\t%d\n"
 179                 "\tdropped_frames\t%d\n",
 180                 s.active_frame, s.first_clear_frame,
 181                 s.n_clear_frames, s.dropped_frames);
 182 #endif
 183
 184         dv->avail = s.n_clear_frames;
 185         dv->index = s.first_clear_frame;
 186         dv->done  = 0;
 187
 188         if (s.dropped_frames) {
 189             av_log(context, AV_LOG_ERROR, "DV1394: Frame drop detected (%d). Reseting ..\n",
 190                     s.dropped_frames);
 191
 192             dv1394_reset(dv);
 193             dv1394_start(dv);
 194         }
 195     }
 196
 197 #ifdef DV1394_DEBUG
 198     av_log(context, AV_LOG_DEBUG, "index %d, avail %d, done %d\n", dv->index, dv->avail,
 199             dv->done);
 200 #endif
 201
 202     size = dv_produce_packet(dv->dv_demux, pkt,
 203                              dv->ring + (dv->index * DV1394_PAL_FRAME_SIZE),
 204                              DV1394_PAL_FRAME_SIZE);
 205     dv->index = (dv->index + 1) % DV1394_RING_FRAMES;
 206     dv->done++; dv->avail--;
 207
 208     return size;
 209 }
 210
 211 static int dv1394_close(AVFormatContext * context)
 212 {
 213     struct dv1394_data *dv = context->priv_data;
 214
 215     /* Shutdown DV1394 receiver */
 216     if (ioctl(dv->fd, DV1394_SHUTDOWN, 0) < 0)
 217         av_log(context, AV_LOG_ERROR, "Failed to shutdown DV1394: %s\n", strerror(errno));
 218
 219     /* Unmap ring buffer */
 220     if (munmap(dv->ring, DV1394_NTSC_FRAME_SIZE * DV1394_RING_FRAMES) < 0)
 221         av_log(context, AV_LOG_ERROR, "Failed to munmap DV1394 ring buffer: %s\n", strerror(errno));
 222
 223     close(dv->fd);
 224     av_free(dv->dv_demux);
 225
 226     return 0;
 227 }
 228
 229 AVInputFormat dv1394_demuxer = {
 230     .name           = "dv1394",
 231     .long_name      = "dv1394 A/V grab",
 232     .priv_data_size = sizeof(struct dv1394_data),
 233     .read_header    = dv1394_read_header,
 234     .read_packet    = dv1394_read_packet,
 235     .read_close     = dv1394_close,
 236     .flags          = AVFMT_NOFILE
 237 };