ffmpeg/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
  30 #include "libavutil/internal.h"
  31 #include "libavutil/log.h"
  32 #include "libavutil/opt.h"
  33 #include "avdevice.h"
  34 #include "libavformat/dv.h"
  35 #include "dv1394.h"
  36
  37 struct dv1394_data {
  38     AVClass *class;
  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)
  84 {
  85     struct dv1394_data *dv = context->priv_data;
  86
  87     dv->dv_demux = avpriv_dv_init_demux(context);
  88     if (!dv->dv_demux)
  89         goto failed;
  90
  91     /* Open and initialize DV1394 device */
  92     dv->fd = avpriv_open(context->filename, O_RDONLY);
  93     if (dv->fd < 0) {
  94         av_log(context, AV_LOG_ERROR, "Failed to open DV interface: %s\n", strerror(errno));
  95         goto failed;
  96     }
  97
  98     if (dv1394_reset(dv) < 0) {
  99         av_log(context, AV_LOG_ERROR, "Failed to initialize DV interface: %s\n", strerror(errno));
 100         goto failed;
 101     }
 102
 103     dv->ring = mmap(NULL, DV1394_PAL_FRAME_SIZE * DV1394_RING_FRAMES,
 104                     PROT_READ, MAP_PRIVATE, dv->fd, 0);
 105     if (dv->ring == MAP_FAILED) {
 106         av_log(context, AV_LOG_ERROR, "Failed to mmap DV ring buffer: %s\n", strerror(errno));
 107         goto failed;
 108     }
 109
 110     if (dv1394_start(dv) < 0)
 111         goto failed;
 112
 113     return 0;
 114
 115 failed:
 116     close(dv->fd);
 117     return AVERROR(EIO);
 118 }
 119
 120 static int dv1394_read_packet(AVFormatContext *context, AVPacket *pkt)
 121 {
 122     struct dv1394_data *dv = context->priv_data;
 123     int size;
 124
 125     size = avpriv_dv_get_packet(dv->dv_demux, pkt);
 126     if (size > 0)
 127         return size;
 128
 129     if (!dv->avail) {
 130         struct dv1394_status s;
 131         struct pollfd p;
 132
 133         if (dv->done) {
 134             /* Request more frames */
 135             if (ioctl(dv->fd, DV1394_RECEIVE_FRAMES, dv->done) < 0) {
 136                 /* This usually means that ring buffer overflowed.
 137                  * We have to reset :(.
 138                  */
 139
 140                 av_log(context, AV_LOG_ERROR, "DV1394: Ring buffer overflow. Reseting ..\n");
 141
 142                 dv1394_reset(dv);
 143                 dv1394_start(dv);
 144             }
 145             dv->done = 0;
 146         }
 147
 148         /* Wait until more frames are available */
 149 restart_poll:
 150         p.fd = dv->fd;
 151         p.events = POLLIN | POLLERR | POLLHUP;
 152         if (poll(&p, 1, -1) < 0) {
 153             if (errno == EAGAIN || errno == EINTR)
 154                 goto restart_poll;
 155             av_log(context, AV_LOG_ERROR, "Poll failed: %s\n", strerror(errno));
 156             return AVERROR(EIO);
 157         }
 158
 159         if (ioctl(dv->fd, DV1394_GET_STATUS, &s) < 0) {
 160             av_log(context, AV_LOG_ERROR, "Failed to get status: %s\n", strerror(errno));
 161             return AVERROR(EIO);
 162         }
 163         av_dlog(context, "DV1394: status\n"
 164                 "\tactive_frame\t%d\n"
 165                 "\tfirst_clear_frame\t%d\n"
 166                 "\tn_clear_frames\t%d\n"
 167                 "\tdropped_frames\t%d\n",
 168                 s.active_frame, s.first_clear_frame,
 169                 s.n_clear_frames, s.dropped_frames);
 170
 171         dv->avail = s.n_clear_frames;
 172         dv->index = s.first_clear_frame;
 173         dv->done  = 0;
 174
 175         if (s.dropped_frames) {
 176             av_log(context, AV_LOG_ERROR, "DV1394: Frame drop detected (%d). Reseting ..\n",
 177                     s.dropped_frames);
 178
 179             dv1394_reset(dv);
 180             dv1394_start(dv);
 181         }
 182     }
 183
 184     av_dlog(context, "index %d, avail %d, done %d\n", dv->index, dv->avail,
 185             dv->done);
 186
 187     size = avpriv_dv_produce_packet(dv->dv_demux, pkt,
 188                              dv->ring + (dv->index * DV1394_PAL_FRAME_SIZE),
 189                              DV1394_PAL_FRAME_SIZE, -1);
 190     dv->index = (dv->index + 1) % DV1394_RING_FRAMES;
 191     dv->done++; dv->avail--;
 192
 193     return size;
 194 }
 195
 196 static int dv1394_close(AVFormatContext * context)
 197 {
 198     struct dv1394_data *dv = context->priv_data;
 199
 200     /* Shutdown DV1394 receiver */
 201     if (ioctl(dv->fd, DV1394_SHUTDOWN, 0) < 0)
 202         av_log(context, AV_LOG_ERROR, "Failed to shutdown DV1394: %s\n", strerror(errno));
 203
 204     /* Unmap ring buffer */
 205     if (munmap(dv->ring, DV1394_NTSC_FRAME_SIZE * DV1394_RING_FRAMES) < 0)
 206         av_log(context, AV_LOG_ERROR, "Failed to munmap DV1394 ring buffer: %s\n", strerror(errno));
 207
 208     close(dv->fd);
 209     av_free(dv->dv_demux);
 210
 211     return 0;
 212 }
 213
 214 static const AVOption options[] = {
 215     { "standard", "", offsetof(struct dv1394_data, format), AV_OPT_TYPE_INT, {.i64 = DV1394_NTSC}, DV1394_NTSC, DV1394_PAL, AV_OPT_FLAG_DECODING_PARAM, "standard" },
 216     { "PAL",      "", 0, AV_OPT_TYPE_CONST, {.i64 = DV1394_PAL},   0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
 217     { "NTSC",     "", 0, AV_OPT_TYPE_CONST, {.i64 = DV1394_NTSC},  0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
 218     { "channel",  "", offsetof(struct dv1394_data, channel), AV_OPT_TYPE_INT, {.i64 = DV1394_DEFAULT_CHANNEL}, 0, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },
 219     { NULL },
 220 };
 221
 222 static const AVClass dv1394_class = {
 223     .class_name = "DV1394 indev",
 224     .item_name  = av_default_item_name,
 225     .option     = options,
 226     .version    = LIBAVUTIL_VERSION_INT,
 227     .category   = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
 228 };
 229
 230 AVInputFormat ff_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     .priv_class     = &dv1394_class,
 239 };