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