/*
  * Linux DV1394 interface
  * Copyright (c) 2003 Max Krasnyansky <maxk@qualcomm.com>
  *

  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or

  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either

  * version 2.1 of the License, or (at your option) any later version.

  *

  * FFmpeg is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public

  * License along with FFmpeg; if not, write to the Free Software

  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  */
 

 #include "config.h"

 #include <unistd.h>
 #include <fcntl.h>

 #include <errno.h>

 #include <poll.h>

 #include <sys/ioctl.h>
 #include <sys/mman.h>
 #include <sys/time.h>
 #include <time.h>
 

 #include "libavutil/log.h"
 #include "libavutil/opt.h"

 #include "avdevice.h"

 #include "libavformat/dv.h"

 #include "dv1394.h"
 
 struct dv1394_data {

     AVClass *class;

     int fd;
     int channel;

     int format;

     uint8_t *ring; /* Ring buffer */

     int index;  /* Current frame index */
     int avail;  /* Number of frames available for reading */
     int done;   /* Number of completed frames */

     DVDemuxContext* dv_demux; /* Generic DV muxing/demuxing context */

 };
 

 /*

  * The trick here is to kludge around well known problem with kernel Ooopsing

  * when you try to capture PAL on a device node configure for NTSC. That's

  * why we have to configure the device node for PAL, and then read only NTSC
  * amount of data.
  */

 static int dv1394_reset(struct dv1394_data *dv)
 {
     struct dv1394_init init;
 

     init.channel     = dv->channel;

     init.api_version = DV1394_API_VERSION;

     init.n_frames    = DV1394_RING_FRAMES;

     init.format      = DV1394_PAL;

 
     if (ioctl(dv->fd, DV1394_INIT, &init) < 0)
         return -1;
 

     dv->avail  = dv->done = 0;

     return 0;
 }
 
 static int dv1394_start(struct dv1394_data *dv)
 {
     /* Tell DV1394 driver to enable receiver */
     if (ioctl(dv->fd, DV1394_START_RECEIVE, 0) < 0) {

         av_log(NULL, AV_LOG_ERROR, "Failed to start receiver: %s\n", strerror(errno));

         return -1;
     }
     return 0;
 }
 
 static int dv1394_read_header(AVFormatContext * context, AVFormatParameters * ap)
 {
     struct dv1394_data *dv = context->priv_data;
 

     dv->dv_demux = avpriv_dv_init_demux(context);

     if (!dv->dv_demux)
         goto failed;

 
     /* Open and initialize DV1394 device */

     dv->fd = open(context->filename, O_RDONLY);

     if (dv->fd < 0) {

         av_log(context, AV_LOG_ERROR, "Failed to open DV interface: %s\n", strerror(errno));

         goto failed;
     }
 
     if (dv1394_reset(dv) < 0) {

         av_log(context, AV_LOG_ERROR, "Failed to initialize DV interface: %s\n", strerror(errno));

         goto failed;
     }
 

     dv->ring = mmap(NULL, DV1394_PAL_FRAME_SIZE * DV1394_RING_FRAMES,

                     PROT_READ, MAP_PRIVATE, dv->fd, 0);

     if (dv->ring == MAP_FAILED) {

         av_log(context, AV_LOG_ERROR, "Failed to mmap DV ring buffer: %s\n", strerror(errno));

         goto failed;
     }
 
     if (dv1394_start(dv) < 0)
         goto failed;
 
     return 0;
 
 failed:
     close(dv->fd);

     return AVERROR(EIO);

 }
 

 static int dv1394_read_packet(AVFormatContext *context, AVPacket *pkt)

 {
     struct dv1394_data *dv = context->priv_data;

     int size;
 

     size = avpriv_dv_get_packet(dv->dv_demux, pkt);

     if (size > 0)

         return size;

 
     if (!dv->avail) {
         struct dv1394_status s;
         struct pollfd p;

 
         if (dv->done) {
             /* Request more frames */
             if (ioctl(dv->fd, DV1394_RECEIVE_FRAMES, dv->done) < 0) {
                 /* This usually means that ring buffer overflowed.
                  * We have to reset :(.
                  */

                 av_log(context, AV_LOG_ERROR, "DV1394: Ring buffer overflow. Reseting ..\n");

                 dv1394_reset(dv);
                 dv1394_start(dv);
             }
             dv->done = 0;
         }

 
         /* Wait until more frames are available */

 restart_poll:
         p.fd = dv->fd;
         p.events = POLLIN | POLLERR | POLLHUP;

         if (poll(&p, 1, -1) < 0) {

             if (errno == EAGAIN || errno == EINTR)
                 goto restart_poll;

             av_log(context, AV_LOG_ERROR, "Poll failed: %s\n", strerror(errno));

             return AVERROR(EIO);

         }
 
         if (ioctl(dv->fd, DV1394_GET_STATUS, &s) < 0) {

             av_log(context, AV_LOG_ERROR, "Failed to get status: %s\n", strerror(errno));

             return AVERROR(EIO);

         }

         av_dlog(context, "DV1394: status\n"

                 "\tactive_frame\t%d\n"
                 "\tfirst_clear_frame\t%d\n"
                 "\tn_clear_frames\t%d\n"
                 "\tdropped_frames\t%d\n",
                 s.active_frame, s.first_clear_frame,
                 s.n_clear_frames, s.dropped_frames);
 
         dv->avail = s.n_clear_frames;
         dv->index = s.first_clear_frame;

         dv->done  = 0;

 
         if (s.dropped_frames) {

             av_log(context, AV_LOG_ERROR, "DV1394: Frame drop detected (%d). Reseting ..\n",

                     s.dropped_frames);
 
             dv1394_reset(dv);
             dv1394_start(dv);
         }
     }
 

     av_dlog(context, "index %d, avail %d, done %d\n", dv->index, dv->avail,

             dv->done);
 

     size = avpriv_dv_produce_packet(dv->dv_demux, pkt,

                              dv->ring + (dv->index * DV1394_PAL_FRAME_SIZE),

                              DV1394_PAL_FRAME_SIZE, -1);

     dv->index = (dv->index + 1) % DV1394_RING_FRAMES;
     dv->done++; dv->avail--;

     return size;

 }
 
 static int dv1394_close(AVFormatContext * context)
 {
     struct dv1394_data *dv = context->priv_data;
 
     /* Shutdown DV1394 receiver */
     if (ioctl(dv->fd, DV1394_SHUTDOWN, 0) < 0)

         av_log(context, AV_LOG_ERROR, "Failed to shutdown DV1394: %s\n", strerror(errno));

 
     /* Unmap ring buffer */
     if (munmap(dv->ring, DV1394_NTSC_FRAME_SIZE * DV1394_RING_FRAMES) < 0)

         av_log(context, AV_LOG_ERROR, "Failed to munmap DV1394 ring buffer: %s\n", strerror(errno));

 
     close(dv->fd);

     av_free(dv->dv_demux);

 
     return 0;
 }
 

 static const AVOption options[] = {

     { "standard", "", offsetof(struct dv1394_data, format), AV_OPT_TYPE_INT, {.dbl = DV1394_NTSC}, DV1394_PAL, DV1394_NTSC, AV_OPT_FLAG_DECODING_PARAM, "standard" },
     { "PAL",      "", 0, AV_OPT_TYPE_CONST, {.dbl = DV1394_PAL},   0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
     { "NTSC",     "", 0, AV_OPT_TYPE_CONST, {.dbl = DV1394_NTSC},  0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
     { "channel",  "", offsetof(struct dv1394_data, channel), AV_OPT_TYPE_INT, {.dbl = DV1394_DEFAULT_CHANNEL}, 0, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },

     { NULL },
 };
 
 static const AVClass dv1394_class = {
     .class_name = "DV1394 indev",
     .item_name  = av_default_item_name,
     .option     = options,
     .version    = LIBAVUTIL_VERSION_INT,
 };
 

 AVInputFormat ff_dv1394_demuxer = {

     .name           = "dv1394",

     .long_name      = NULL_IF_CONFIG_SMALL("DV1394 A/V grab"),

     .priv_data_size = sizeof(struct dv1394_data),
     .read_header    = dv1394_read_header,
     .read_packet    = dv1394_read_packet,
     .read_close     = dv1394_close,

     .flags          = AVFMT_NOFILE,
     .priv_class     = &dv1394_class,

 };