libavdevice/dv1394.c

   1 /*
   2  * Linux DV1394 interface
   3  * Copyright (c) 2003 Max Krasnyansky <maxk@qualcomm.com>
   4  *
   5  * This file is part of Libav.
   6  *
   7  * Libav 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  * Libav 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 Libav; 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
  30 #include "libavutil/log.h"
  31 #include "libavutil/opt.h"
  32 #include "libavformat/avformat.h"
  33 #include "libavformat/dv.h"
  34 #include "dv1394.h"
  35
  36 struct dv1394_data {
  37     AVClass *class;
  38     int fd;
  39     int channel;
  40     int format;
  41
  42     uint8_t *ring; /* Ring buffer */
  43     int index;  /* Current frame index */
  44     int avail;  /* Number of frames available for reading */
  45     int done;   /* Number of completed frames */
  46
  47     DVDemuxContext* dv_demux; /* Generic DV muxing/demuxing context */
  48 };
  49
  50 /*
  51  * The trick here is to kludge around well known problem with kernel Ooopsing
  52  * when you try to capture PAL on a device node configure for NTSC. That's
  53  * why we have to configure the device node for PAL, and then read only NTSC
  54  * amount of data.
  55  */
  56 static int dv1394_reset(struct dv1394_data *dv)
  57 {
  58     struct dv1394_init init;
  59
  60     init.channel     = dv->channel;
  61     init.api_version = DV1394_API_VERSION;
  62     init.n_frames    = DV1394_RING_FRAMES;
  63     init.format      = DV1394_PAL;
  64
  65     if (ioctl(dv->fd, DV1394_INIT, &init) < 0)
  66         return -1;
  67
  68     dv->avail  = dv->done = 0;
  69     return 0;
  70 }
  71
  72 static int dv1394_start(struct dv1394_data *dv)
  73 {
  74     /* Tell DV1394 driver to enable receiver */
  75     if (ioctl(dv->fd, DV1394_START_RECEIVE, 0) < 0) {
  76         av_log(NULL, AV_LOG_ERROR, "Failed to start receiver: %s\n", strerror(errno));
  77         return -1;
  78     }
  79     return 0;
  80 }
  81
  82 static int dv1394_read_header(AVFormatContext * context)
  83 {
  84     struct dv1394_data *dv = context->priv_data;
  85
  86     dv->dv_demux = avpriv_dv_init_demux(context);
  87     if (!dv->dv_demux)
  88         goto failed;
  89
  90     /* Open and initialize DV1394 device */
  91     dv->fd = open(context->filename, O_RDONLY);
  92     if (dv->fd < 0) {
  93         av_log(context, AV_LOG_ERROR, "Failed to open DV interface: %s\n", strerror(errno));
  94         goto failed;
  95     }
  96
  97     if (dv1394_reset(dv) < 0) {
  98         av_log(context, AV_LOG_ERROR, "Failed to initialize DV interface: %s\n", strerror(errno));
  99         goto failed;
 100     }
 101
 102     dv->ring = mmap(NULL, DV1394_PAL_FRAME_SIZE * DV1394_RING_FRAMES,
 103                     PROT_READ, MAP_PRIVATE, dv->fd, 0);
 104     if (dv->ring == MAP_FAILED) {
 105         av_log(context, AV_LOG_ERROR, "Failed to mmap DV ring buffer: %s\n", strerror(errno));
 106         goto failed;
 107     }
 108
 109     if (dv1394_start(dv) < 0)
 110         goto failed;
 111
 112     return 0;
 113
 114 failed:
 115     close(dv->fd);
 116     return AVERROR(EIO);
 117 }
 118
 119 static int dv1394_read_packet(AVFormatContext *context, AVPacket *pkt)
 120 {
 121     struct dv1394_data *dv = context->priv_data;
 122     int size;
 123
 124     size = avpriv_dv_get_packet(dv->dv_demux, pkt);
 125     if (size > 0)
 126         return size;
 127
 128     if (!dv->avail) {
 129         struct dv1394_status s;
 130         struct pollfd p;
 131
 132         if (dv->done) {
 133             /* Request more frames */
 134             if (ioctl(dv->fd, DV1394_RECEIVE_FRAMES, dv->done) < 0) {
 135                 /* This usually means that ring buffer overflowed.
 136                  * We have to reset :(.
 137                  */
 138
 139                 av_log(context, AV_LOG_ERROR, "DV1394: Ring buffer overflow. Reseting ..\n");
 140
 141                 dv1394_reset(dv);
 142                 dv1394_start(dv);
 143             }
 144             dv->done = 0;
 145         }
 146
 147         /* Wait until more frames are available */
 148 restart_poll:
 149         p.fd = dv->fd;
 150         p.events = POLLIN | POLLERR | POLLHUP;
 151         if (poll(&p, 1, -1) < 0) {
 152             if (errno == EAGAIN || errno == EINTR)
 153                 goto restart_poll;
 154             av_log(context, AV_LOG_ERROR, "Poll failed: %s\n", strerror(errno));
 155             return AVERROR(EIO);
 156         }
 157
 158         if (ioctl(dv->fd, DV1394_GET_STATUS, &s) < 0) {
 159             av_log(context, AV_LOG_ERROR, "Failed to get status: %s\n", strerror(errno));
 160             return AVERROR(EIO);
 161         }
 162         av_dlog(context, "DV1394: status\n"
 163                 "\tactive_frame\t%d\n"
 164                 "\tfirst_clear_frame\t%d\n"
 165                 "\tn_clear_frames\t%d\n"
 166                 "\tdropped_frames\t%d\n",
 167                 s.active_frame, s.first_clear_frame,
 168                 s.n_clear_frames, s.dropped_frames);
 169
 170         dv->avail = s.n_clear_frames;
 171         dv->index = s.first_clear_frame;
 172         dv->done  = 0;
 173
 174         if (s.dropped_frames) {
 175             av_log(context, AV_LOG_ERROR, "DV1394: Frame drop detected (%d). Reseting ..\n",
 176                     s.dropped_frames);
 177
 178             dv1394_reset(dv);
 179             dv1394_start(dv);
 180         }
 181     }
 182
 183     av_dlog(context, "index %d, avail %d, done %d\n", dv->index, dv->avail,
 184             dv->done);
 185
 186     size = avpriv_dv_produce_packet(dv->dv_demux, pkt,
 187                              dv->ring + (dv->index * DV1394_PAL_FRAME_SIZE),
 188                              DV1394_PAL_FRAME_SIZE);
 189     dv->index = (dv->index + 1) % DV1394_RING_FRAMES;
 190     dv->done++; dv->avail--;
 191
 192     return size;
 193 }
 194
 195 static int dv1394_close(AVFormatContext * context)
 196 {
 197     struct dv1394_data *dv = context->priv_data;
 198
 199     /* Shutdown DV1394 receiver */
 200     if (ioctl(dv->fd, DV1394_SHUTDOWN, 0) < 0)
 201         av_log(context, AV_LOG_ERROR, "Failed to shutdown DV1394: %s\n", strerror(errno));
 202
 203     /* Unmap ring buffer */
 204     if (munmap(dv->ring, DV1394_NTSC_FRAME_SIZE * DV1394_RING_FRAMES) < 0)
 205         av_log(context, AV_LOG_ERROR, "Failed to munmap DV1394 ring buffer: %s\n", strerror(errno));
 206
 207     close(dv->fd);
 208     av_free(dv->dv_demux);
 209
 210     return 0;
 211 }
 212
 213 static const AVOption options[] = {
 214     { "standard", "", offsetof(struct dv1394_data, format), AV_OPT_TYPE_INT, {.i64 = DV1394_NTSC}, DV1394_NTSC, DV1394_PAL, AV_OPT_FLAG_DECODING_PARAM, "standard" },
 215     { "PAL",      "", 0, AV_OPT_TYPE_CONST, {.i64 = DV1394_PAL},   0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
 216     { "NTSC",     "", 0, AV_OPT_TYPE_CONST, {.i64 = DV1394_NTSC},  0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
 217     { "channel",  "", offsetof(struct dv1394_data, channel), AV_OPT_TYPE_INT, {.i64 = DV1394_DEFAULT_CHANNEL}, 0, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },
 218     { NULL },
 219 };
 220
 221 static const AVClass dv1394_class = {
 222     .class_name = "DV1394 indev",
 223     .item_name  = av_default_item_name,
 224     .option     = options,
 225     .version    = LIBAVUTIL_VERSION_INT,
 226 };
 227
 228 AVInputFormat ff_dv1394_demuxer = {
 229     .name           = "dv1394",
 230     .long_name      = NULL_IF_CONFIG_SMALL("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     .priv_class     = &dv1394_class,
 237 };