src/lib/writer.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 #include <libdcp/picture_asset.h>
  21 #include <libdcp/sound_asset.h>
  22 #include <libdcp/reel.h>
  23 #include "writer.h"
  24 #include "compose.hpp"
  25 #include "film.h"
  26 #include "format.h"
  27 #include "log.h"
  28 #include "dcp_video_frame.h"
  29
  30 using std::make_pair;
  31 using std::pair;
  32 using boost::shared_ptr;
  33
  34 unsigned int const Writer::_maximum_frames_in_memory = 8;
  35
  36 Writer::Writer (shared_ptr<const Film> f)
  37         : _film (f)
  38         , _thread (0)
  39         , _finish (false)
  40         , _last_written_frame (-1)
  41 {
  42         _picture_asset.reset (
  43                 new libdcp::MonoPictureAsset (
  44                         _film->dir (_film->dcp_name()),
  45                         String::compose ("video_%1.mxf", 0),
  46                         DCPFrameRate (_film->frames_per_second()).frames_per_second,
  47                         _film->format()->dcp_size()
  48                         )
  49                 );
  50
  51         _picture_asset_writer = _picture_asset->start_write ();
  52
  53         if (_film->audio_channels() > 0) {
  54                 _sound_asset.reset (
  55                         new libdcp::SoundAsset (
  56                                 _film->dir (_film->dcp_name()),
  57                                 String::compose ("audio_%1.mxf", 0),
  58                                 DCPFrameRate (_film->frames_per_second()).frames_per_second,
  59                                 _film->audio_channels(),
  60                                 _film->audio_stream()->sample_rate()
  61                                 )
  62                         );
  63
  64                 _sound_asset_writer = _sound_asset->start_write ();
  65         }
  66
  67         _thread = new boost::thread (boost::bind (&Writer::thread, this));
  68 }
  69
  70 void
  71 Writer::write (shared_ptr<const EncodedData> encoded, int frame)
  72 {
  73         boost::mutex::scoped_lock lock (_mutex);
  74         _queue.push_back (make_pair (encoded, frame));
  75         _condition.notify_all ();
  76 }
  77
  78 /** This method is not thread safe */
  79 void
  80 Writer::write (shared_ptr<const AudioBuffers> audio)
  81 {
  82         _sound_asset_writer->write (audio->data(), audio->frames());
  83 }
  84
  85 struct QueueSorter
  86 {
  87         bool operator() (pair<shared_ptr<const EncodedData>, int> const & a, pair<shared_ptr<const EncodedData>, int> const & b) {
  88                 return a.second < b.second;
  89         }
  90 };
  91
  92 void
  93 Writer::thread ()
  94 {
  95         while (1)
  96         {
  97                 boost::mutex::scoped_lock lock (_mutex);
  98
  99                 while (1) {
 100                         if (_finish ||
 101                             _queue.size() > _maximum_frames_in_memory ||
 102                             (!_queue.empty() && _queue.front().second == (_last_written_frame + 1))) {
 103
 104                                     break;
 105                             }
 106
 107                             TIMING ("writer sleeps with a queue of %1; %2 pending", _queue.size(), _pending.size());
 108                             _condition.wait (lock);
 109                             TIMING ("writer wakes with a queue of %1", _queue.size());
 110
 111                             _queue.sort (QueueSorter ());
 112                 }
 113
 114                 if (_finish && _queue.empty() && _pending.empty()) {
 115                         return;
 116                 }
 117
 118                 /* Write any frames that we can write; i.e. those that are in sequence */
 119                 while (!_queue.empty() && _queue.front().second == (_last_written_frame + 1)) {
 120                         pair<boost::shared_ptr<const EncodedData>, int> encoded = _queue.front ();
 121                         _queue.pop_front ();
 122
 123                         lock.unlock ();
 124                         _film->log()->log (String::compose ("Writer writes %1 to MXF", encoded.second));
 125                         if (encoded.first) {
 126                                 _picture_asset_writer->write (encoded.first->data(), encoded.first->size());
 127                                 _last_written = encoded.first;
 128                         } else {
 129                                 _picture_asset_writer->write (_last_written->data(), _last_written->size());
 130                         }
 131                         lock.lock ();
 132
 133                         ++_last_written_frame;
 134                 }
 135
 136                 while (_queue.size() > _maximum_frames_in_memory) {
 137                         /* Too many frames in memory which can't yet be written to the stream.
 138                            Put some to disk.
 139                         */
 140
 141                         pair<boost::shared_ptr<const EncodedData>, int> encoded = _queue.back ();
 142                         _queue.pop_back ();
 143                         if (!encoded.first) {
 144                                 /* This is a `repeat-last' frame, so no need to write it to disk */
 145                                 continue;
 146                         }
 147
 148                         lock.unlock ();
 149                         _film->log()->log (String::compose ("Writer full (awaiting %1); pushes %2 to disk", _last_written_frame + 1, encoded.second));
 150                         encoded.first->write (_film, encoded.second);
 151                         lock.lock ();
 152
 153                         _pending.push_back (encoded.second);
 154                 }
 155
 156                 while (_queue.size() < _maximum_frames_in_memory && !_pending.empty()) {
 157                         /* We have some space in memory.  Fetch some frames back off disk. */
 158
 159                         _pending.sort ();
 160                         int const fetch = _pending.front ();
 161
 162                         lock.unlock ();
 163                         _film->log()->log (String::compose ("Writer pulls %1 back from disk", fetch));
 164                         shared_ptr<const EncodedData> encoded;
 165                         if (boost::filesystem::exists (_film->frame_out_path (fetch, false))) {
 166                                 /* It's an actual frame (not a repeat-last); load it in */
 167                                 encoded.reset (new EncodedData (_film->frame_out_path (fetch, false)));
 168                         }
 169                         lock.lock ();
 170
 171                         _queue.push_back (make_pair (encoded, fetch));
 172                         _pending.remove (fetch);
 173                 }
 174         }
 175
 176 }
 177
 178 void
 179 Writer::finish ()
 180 {
 181         if (!_thread) {
 182                 return;
 183         }
 184
 185         boost::mutex::scoped_lock lock (_mutex);
 186         _finish = true;
 187         _condition.notify_all ();
 188         lock.unlock ();
 189
 190         _thread->join ();
 191         delete _thread;
 192         _thread = 0;
 193
 194         _picture_asset_writer->finalize ();
 195         _sound_asset_writer->finalize ();
 196
 197
 198         int const frames = _film->dcp_intrinsic_duration().get();
 199         int const duration = frames - _film->trim_start() - _film->trim_end();
 200
 201         _picture_asset->set_entry_point (_film->trim_start ());
 202         _picture_asset->set_duration (duration);
 203         _sound_asset->set_entry_point (_film->trim_start ());
 204         _sound_asset->set_duration (duration);
 205
 206         libdcp::DCP dcp (_film->dir (_film->dcp_name()));
 207         DCPFrameRate dfr (_film->frames_per_second ());
 208
 209         shared_ptr<libdcp::CPL> cpl (
 210                 new libdcp::CPL (_film->dir (_film->dcp_name()), _film->dcp_name(), _film->dcp_content_type()->libdcp_kind (), frames, dfr.frames_per_second)
 211                 );
 212
 213         dcp.add_cpl (cpl);
 214
 215         cpl->add_reel (shared_ptr<libdcp::Reel> (new libdcp::Reel (
 216                                                          _picture_asset,
 217                                                          _sound_asset,
 218                                                          shared_ptr<libdcp::SubtitleAsset> ()
 219                                                          )
 220                                ));
 221
 222         dcp.write_xml ();
 223 }
 224
 225 /** Tell the writer that frame `f' should be a repeat of the frame before it */
 226 void
 227 Writer::repeat (int f)
 228 {
 229         boost::mutex::scoped_lock lock (_mutex);
 230         _queue.push_back (make_pair (shared_ptr<const EncodedData> (), f));
 231 }