src/lib/butler.cc

   1 /*
   2     Copyright (C) 2016-2017 Carl Hetherington <cth@carlh.net>
   3
   4     This file is part of DCP-o-matic.
   5
   6     DCP-o-matic is free software; you can redistribute it and/or modify
   7     it under the terms of the GNU General Public License as published by
   8     the Free Software Foundation; either version 2 of the License, or
   9     (at your option) any later version.
  10
  11     DCP-o-matic is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14     GNU General Public License for more details.
  15
  16     You should have received a copy of the GNU General Public License
  17     along with DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
  18
  19 */
  20
  21 #include "butler.h"
  22 #include "player.h"
  23 #include "util.h"
  24 #include <boost/weak_ptr.hpp>
  25 #include <boost/shared_ptr.hpp>
  26
  27 using std::cout;
  28 using std::pair;
  29 using std::make_pair;
  30 using boost::weak_ptr;
  31 using boost::shared_ptr;
  32 using boost::bind;
  33 using boost::optional;
  34
  35 /** Video readahead in frames */
  36 #define VIDEO_READAHEAD 10
  37 /** Audio readahead in frames */
  38 #define AUDIO_READAHEAD (48000*5)
  39
  40 Butler::Butler (weak_ptr<const Film> film, shared_ptr<Player> player, AudioMapping audio_mapping, int audio_channels)
  41         : _film (film)
  42         , _player (player)
  43         , _pending_seek_accurate (false)
  44         , _finished (false)
  45         , _died (false)
  46         , _stop_thread (false)
  47         , _audio_mapping (audio_mapping)
  48         , _audio_channels (audio_channels)
  49         , _disable_audio (false)
  50 {
  51         _player_video_connection = _player->Video.connect (bind (&Butler::video, this, _1, _2));
  52         _player_audio_connection = _player->Audio.connect (bind (&Butler::audio, this, _1));
  53         _player_changed_connection = _player->Changed.connect (bind (&Butler::player_changed, this));
  54         _thread = new boost::thread (bind (&Butler::thread, this));
  55 }
  56
  57 Butler::~Butler ()
  58 {
  59         {
  60                 boost::mutex::scoped_lock lm (_mutex);
  61                 _stop_thread = true;
  62         }
  63
  64         _thread->interrupt ();
  65         try {
  66                 _thread->join ();
  67         } catch (boost::thread_interrupted& e) {
  68                 /* No problem */
  69         }
  70         delete _thread;
  71 }
  72
  73 /** Caller must hold a lock on _mutex */
  74 bool
  75 Butler::should_run () const
  76 {
  77         return (_video.size() < VIDEO_READAHEAD || (!_disable_audio && _audio.size() < AUDIO_READAHEAD)) && !_stop_thread && !_finished && !_died;
  78 }
  79
  80 void
  81 Butler::thread ()
  82 try
  83 {
  84         while (true) {
  85                 boost::mutex::scoped_lock lm (_mutex);
  86
  87                 /* Wait until we have something to do */
  88                 while (!should_run() && !_pending_seek_position) {
  89                         _summon.wait (lm);
  90                 }
  91
  92                 /* Do any seek that has been requested */
  93                 if (_pending_seek_position) {
  94                         _finished = false;
  95                         _player->seek (*_pending_seek_position, _pending_seek_accurate);
  96                         _pending_seek_position = optional<DCPTime> ();
  97                 }
  98
  99                 /* Fill _video and _audio.  Don't try to carry on if a pending seek appears
 100                    while lm is unlocked, as in that state nothing will be added to
 101                    _video/_audio.
 102                 */
 103                 while (should_run() && !_pending_seek_position) {
 104                         lm.unlock ();
 105                         bool const r = _player->pass ();
 106                         lm.lock ();
 107                         if (r) {
 108                                 _finished = true;
 109                                 _arrived.notify_all ();
 110                                 break;
 111                         }
 112                         _arrived.notify_all ();
 113                 }
 114         }
 115 } catch (boost::thread_interrupted) {
 116         /* The butler thread is being terminated */
 117         boost::mutex::scoped_lock lm (_mutex);
 118         _finished = true;
 119         _arrived.notify_all ();
 120 } catch (...) {
 121         store_current ();
 122         boost::mutex::scoped_lock lm (_mutex);
 123         _died = true;
 124         _arrived.notify_all ();
 125 }
 126
 127 pair<shared_ptr<PlayerVideo>, DCPTime>
 128 Butler::get_video ()
 129 {
 130         boost::mutex::scoped_lock lm (_mutex);
 131
 132         /* Wait for data if we have none */
 133         while (_video.empty() && !_finished && !_died) {
 134                 _arrived.wait (lm);
 135         }
 136
 137         if (_video.empty()) {
 138                 return make_pair (shared_ptr<PlayerVideo>(), DCPTime());
 139         }
 140
 141         pair<shared_ptr<PlayerVideo>, DCPTime> const r = _video.get ();
 142         _summon.notify_all ();
 143         return r;
 144 }
 145
 146 void
 147 Butler::seek (DCPTime position, bool accurate)
 148 {
 149         boost::mutex::scoped_lock lm (_mutex);
 150         if (_died) {
 151                 return;
 152         }
 153
 154         _video.clear ();
 155         _audio.clear ();
 156         _finished = false;
 157         _pending_seek_position = position;
 158         _pending_seek_accurate = accurate;
 159         _summon.notify_all ();
 160 }
 161
 162 void
 163 Butler::video (shared_ptr<PlayerVideo> video, DCPTime time)
 164 {
 165         {
 166                 boost::mutex::scoped_lock lm (_mutex);
 167                 if (_pending_seek_position) {
 168                         /* Don't store any video while a seek is pending */
 169                         return;
 170                 }
 171         }
 172
 173         _video.put (video, time);
 174 }
 175
 176 void
 177 Butler::audio (shared_ptr<AudioBuffers> audio)
 178 {
 179         {
 180                 boost::mutex::scoped_lock lm (_mutex);
 181                 if (_pending_seek_position || _disable_audio) {
 182                         /* Don't store any audio while a seek is pending, or if audio is disabled */
 183                         return;
 184                 }
 185         }
 186
 187         _audio.put (remap (audio, _audio_channels, _audio_mapping));
 188 }
 189
 190 void
 191 Butler::player_changed ()
 192 {
 193         optional<DCPTime> t;
 194
 195         {
 196                 boost::mutex::scoped_lock lm (_mutex);
 197                 t = _video.earliest ();
 198         }
 199
 200         if (t) {
 201                 seek (*t, true);
 202         } else {
 203                 _video.clear ();
 204                 _audio.clear ();
 205         }
 206 }
 207
 208 void
 209 Butler::get_audio (float* out, Frame frames)
 210 {
 211         _audio.get (out, _audio_channels, frames);
 212         _summon.notify_all ();
 213 }
 214
 215 void
 216 Butler::disable_audio ()
 217 {
 218         boost::mutex::scoped_lock lm (_mutex);
 219         _disable_audio = true;
 220 }