src/lib/transcoder.cc

   1 /*
   2     Copyright (C) 2012 Carl Hetherington <cth@carlh.net>
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17
  18 */
  19
  20 /** @file  src/transcoder.cc
  21  *  @brief A class which takes a Film and some Options, then uses those to transcode the film.
  22  *
  23  *  A decoder is selected according to the content type, and the encoder can be specified
  24  *  as a parameter to the constructor.
  25  */
  26
  27 #include <iostream>
  28 #include <boost/signals2.hpp>
  29 #include "transcoder.h"
  30 #include "encoder.h"
  31 #include "decoder_factory.h"
  32 #include "film.h"
  33 #include "matcher.h"
  34 #include "delay_line.h"
  35 #include "options.h"
  36 #include "gain.h"
  37 #include "video_decoder.h"
  38 #include "audio_decoder.h"
  39
  40 using std::string;
  41 using std::cout;
  42 using boost::shared_ptr;
  43 using boost::dynamic_pointer_cast;
  44
  45 /** Construct a transcoder using a Decoder that we create and a supplied Encoder.
  46  *  @param f Film that we are transcoding.
  47  *  @param o Options.
  48  *  @param j Job that we are running under, or 0.
  49  *  @param e Encoder to use.
  50  */
  51 Transcoder::Transcoder (shared_ptr<Film> f, shared_ptr<const Options> o, Job* j, shared_ptr<Encoder> e)
  52         : _job (j)
  53         , _encoder (e)
  54         , _decoders (decoder_factory (f, o, j))
  55 {
  56         assert (_encoder);
  57
  58         if (f->audio_stream()) {
  59                 shared_ptr<AudioStream> st = f->audio_stream();
  60                 _matcher.reset (new Matcher (f->log(), st->sample_rate(), f->frames_per_second()));
  61                 _delay_line.reset (new DelayLine (f->log(), st->channels(), f->audio_delay() * st->sample_rate() / 1000));
  62                 _gain.reset (new Gain (f->log(), f->audio_gain()));
  63         }
  64
  65         /* Set up the decoder to use the film's set streams */
  66         _decoders.first->set_subtitle_stream (f->subtitle_stream ());
  67         if (_decoders.second) {
  68                 _decoders.second->set_audio_stream (f->audio_stream ());
  69         }
  70
  71         if (_matcher) {
  72                 _decoders.first->connect_video (_matcher);
  73                 _matcher->connect_video (_encoder);
  74         } else {
  75                 _decoders.first->connect_video (_encoder);
  76         }
  77
  78         if (_matcher && _delay_line && _decoders.second) {
  79                 _decoders.second->connect_audio (_delay_line);
  80                 _delay_line->connect_audio (_matcher);
  81                 _matcher->connect_audio (_gain);
  82                 _gain->connect_audio (_encoder);
  83         }
  84 }
  85
  86 /** Run the decoder, passing its output to the encoder, until the decoder
  87  *  has no more data to present.
  88  */
  89 void
  90 Transcoder::go ()
  91 {
  92         _encoder->process_begin ();
  93         try {
  94                 bool done[2] = { false, false };
  95
  96                 while (1) {
  97                         if (!done[0]) {
  98                                 done[0] = _decoders.first->pass ();
  99                                 _decoders.first->set_progress ();
 100                         }
 101
 102                         if (!done[1] && _decoders.second && dynamic_pointer_cast<Decoder> (_decoders.second) != dynamic_pointer_cast<Decoder> (_decoders.first)) {
 103                                 done[1] = _decoders.second->pass ();
 104                         } else {
 105                                 done[1] = true;
 106                         }
 107
 108                         if (done[0] && done[1]) {
 109                                 break;
 110                         }
 111                 }
 112
 113         } catch (...) {
 114                 _encoder->process_end ();
 115                 throw;
 116         }
 117
 118         if (_delay_line) {
 119                 _delay_line->process_end ();
 120         }
 121         if (_matcher) {
 122                 _matcher->process_end ();
 123         }
 124         if (_gain) {
 125                 _gain->process_end ();
 126         }
 127         _encoder->process_end ();
 128 }