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 <poll.h>
  27 #include <sys/ioctl.h>
  28 #include <sys/mman.h>
  29 #include <sys/time.h>
  30 #include <time.h>
  31 #include <strings.h>
  32
  33 #include "libavformat/avformat.h"
  34
  35 #undef DV1394_DEBUG
  36
  37 #include "libavformat/dv.h"
  38 #include "dv1394.h"
  39
  40 struct dv1394_data {
  41     int fd;
  42     int channel;
  43     int format;
  44
  45     uint8_t *ring; /* Ring buffer */
  46     int index;  /* Current frame index */
  47     int avail;  /* Number of frames available for reading */
  48     int done;   /* Number of completed frames */
  49
  50     DVDemuxContext* dv_demux; /* Generic DV muxing/demuxing context */
  51 };
  52
  53 /*
  54  * The trick here is to kludge around well known problem with kernel Ooopsing
  55  * when you try to capture PAL on a device node configure for NTSC. That's
  56  * why we have to configure the device node for PAL, and then read only NTSC
  57  * amount of data.
  58  */
  59 static int dv1394_reset(struct dv1394_data *dv)
  60 {
  61     struct dv1394_init init;
  62
  63     init.channel     = dv->channel;
  64     init.api_version = DV1394_API_VERSION;
  65     init.n_frames    = DV1394_RING_FRAMES;
  66     init.format      = DV1394_PAL;
  67
  68     if (ioctl(dv->fd, DV1394_INIT, &init) < 0)
  69         return -1;
  70
  71     dv->avail  = dv->done = 0;
  72     return 0;
  73 }
  74
  75 static int dv1394_start(struct dv1394_data *dv)
  76 {
  77     /* Tell DV1394 driver to enable receiver */
  78     if (ioctl(dv->fd, DV1394_START_RECEIVE, 0) < 0) {
  79         av_log(NULL, AV_LOG_ERROR, "Failed to start receiver: %s\n", strerror(errno));
  80         return -1;
  81     }
  82     return 0;
  83 }
  84
  85 static int dv1394_read_header(AVFormatContext * context, AVFormatParameters * ap)
  86 {
  87     struct dv1394_data *dv = context->priv_data;
  88
  89     dv->dv_demux = dv_init_demux(context);
  90     if (!dv->dv_demux)
  91         goto failed;
  92
  93     if (ap->standard && !strcasecmp(ap->standard, "pal"))
  94         dv->format = DV1394_PAL;
  95     else
  96         dv->format = DV1394_NTSC;
  97
  98     if (ap->channel)
  99         dv->channel = ap->channel;
 100     else
 101         dv->channel = DV1394_DEFAULT_CHANNEL;
 102
 103     /* Open and initialize DV1394 device */
 104     dv->fd = open(context->filename, O_RDONLY);
 105     if (dv->fd < 0) {
 106         av_log(context, AV_LOG_ERROR, "Failed to open DV interface: %s\n", strerror(errno));
 107         goto failed;
 108     }
 109
 110     if (dv1394_reset(dv) < 0) {
 111         av_log(context, AV_LOG_ERROR, "Failed to initialize DV interface: %s\n", strerror(errno));
 112         goto failed;
 113     }
 114
 115     dv->ring = mmap(NULL, DV1394_PAL_FRAME_SIZE * DV1394_RING_FRAMES,
 116                     PROT_READ, MAP_PRIVATE, dv->fd, 0);
 117     if (dv->ring == MAP_FAILED) {
 118         av_log(context, AV_LOG_ERROR, "Failed to mmap DV ring buffer: %s\n", strerror(errno));
 119         goto failed;
 120     }
 121
 122     if (dv1394_start(dv) < 0)
 123         goto failed;
 124
 125     return 0;
 126
 127 failed:
 128     close(dv->fd);
 129     return AVERROR(EIO);
 130 }
 131
 132 static int dv1394_read_packet(AVFormatContext *context, AVPacket *pkt)
 133 {
 134     struct dv1394_data *dv = context->priv_data;
 135     int size;
 136
 137     size = dv_get_packet(dv->dv_demux, pkt);
 138     if (size > 0)
 139         return size;
 140
 141     if (!dv->avail) {
 142         struct dv1394_status s;
 143         struct pollfd p;
 144
 145         if (dv->done) {
 146             /* Request more frames */
 147             if (ioctl(dv->fd, DV1394_RECEIVE_FRAMES, dv->done) < 0) {
 148                 /* This usually means that ring buffer overflowed.
 149                  * We have to reset :(.
 150                  */
 151
 152                 av_log(context, AV_LOG_ERROR, "DV1394: Ring buffer overflow. Reseting ..\n");
 153
 154                 dv1394_reset(dv);
 155                 dv1394_start(dv);
 156             }
 157             dv->done = 0;
 158         }
 159
 160         /* Wait until more frames are available */
 161 restart_poll:
 162         p.fd = dv->fd;
 163         p.events = POLLIN | POLLERR | POLLHUP;
 164         if (poll(&p, 1, -1) < 0) {
 165             if (errno == EAGAIN || errno == EINTR)
 166                 goto restart_poll;
 167             av_log(context, AV_LOG_ERROR, "Poll failed: %s\n", strerror(errno));
 168             return AVERROR(EIO);
 169         }
 170
 171         if (ioctl(dv->fd, DV1394_GET_STATUS, &s) < 0) {
 172             av_log(context, AV_LOG_ERROR, "Failed to get status: %s\n", strerror(errno));
 173             return AVERROR(EIO);
 174         }
 175 #ifdef DV1394_DEBUG
 176         av_log(context, AV_LOG_DEBUG, "DV1394: status\n"
 177                 "\tactive_frame\t%d\n"
 178                 "\tfirst_clear_frame\t%d\n"
 179                 "\tn_clear_frames\t%d\n"
 180                 "\tdropped_frames\t%d\n",
 181                 s.active_frame, s.first_clear_frame,
 182                 s.n_clear_frames, s.dropped_frames);
 183 #endif
 184
 185         dv->avail = s.n_clear_frames;
 186         dv->index = s.first_clear_frame;
 187         dv->done  = 0;
 188
 189         if (s.dropped_frames) {
 190             av_log(context, AV_LOG_ERROR, "DV1394: Frame drop detected (%d). Reseting ..\n",
 191                     s.dropped_frames);
 192
 193             dv1394_reset(dv);
 194             dv1394_start(dv);
 195         }
 196     }
 197
 198 #ifdef DV1394_DEBUG
 199     av_log(context, AV_LOG_DEBUG, "index %d, avail %d, done %d\n", dv->index, dv->avail,
 200             dv->done);
 201 #endif
 202
 203     size = dv_produce_packet(dv->dv_demux, pkt,
 204                              dv->ring + (dv->index * DV1394_PAL_FRAME_SIZE),
 205                              DV1394_PAL_FRAME_SIZE);
 206     dv->index = (dv->index + 1) % DV1394_RING_FRAMES;
 207     dv->done++; dv->avail--;
 208
 209     return size;
 210 }
 211
 212 static int dv1394_close(AVFormatContext * context)
 213 {
 214     struct dv1394_data *dv = context->priv_data;
 215
 216     /* Shutdown DV1394 receiver */
 217     if (ioctl(dv->fd, DV1394_SHUTDOWN, 0) < 0)
 218         av_log(context, AV_LOG_ERROR, "Failed to shutdown DV1394: %s\n", strerror(errno));
 219
 220     /* Unmap ring buffer */
 221     if (munmap(dv->ring, DV1394_NTSC_FRAME_SIZE * DV1394_RING_FRAMES) < 0)
 222         av_log(context, AV_LOG_ERROR, "Failed to munmap DV1394 ring buffer: %s\n", strerror(errno));
 223
 224     close(dv->fd);
 225     av_free(dv->dv_demux);
 226
 227     return 0;
 228 }
 229
 230 AVInputFormat dv1394_demuxer = {
 231     .name           = "dv1394",
 232     .long_name      = NULL_IF_CONFIG_SMALL("DV1394 A/V grab"),
 233     .priv_data_size = sizeof(struct dv1394_data),
 234     .read_header    = dv1394_read_header,
 235     .read_packet    = dv1394_read_packet,
 236     .read_close     = dv1394_close,
 237     .flags          = AVFMT_NOFILE
 238 };