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<Film> f)
  37         : _film (f)
  38         , _thread (0)
  39         , _finish (false)
  40         , _last_written_frame (-1)
  41 {
  42         /* Create our picture asset in a subdirectory, named according to the
  43            film's parameters which affect the video output.  We will hard-link
  44            it into the DCP later.
  45         */
  46
  47         _picture_asset.reset (
  48                 new libdcp::MonoPictureAsset (
  49                         _film->video_mxf_dir (),
  50                         _film->video_mxf_filename (),
  51                         DCPFrameRate (_film->frames_per_second()).frames_per_second,
  52                         _film->format()->dcp_size()
  53                         )
  54                 );
  55
  56         _picture_asset_writer = _picture_asset->start_write ();
  57
  58         if (_film->audio_channels() > 0) {
  59                 _sound_asset.reset (
  60                         new libdcp::SoundAsset (
  61                                 _film->dir (_film->dcp_name()),
  62                                 "audio.mxf",
  63                                 DCPFrameRate (_film->frames_per_second()).frames_per_second,
  64                                 _film->audio_channels(),
  65                                 dcp_audio_sample_rate (_film->audio_stream()->sample_rate())
  66                                 )
  67                         );
  68
  69                 _sound_asset_writer = _sound_asset->start_write ();
  70         }
  71
  72         _thread = new boost::thread (boost::bind (&Writer::thread, this));
  73 }
  74
  75 void
  76 Writer::write (shared_ptr<const EncodedData> encoded, int frame)
  77 {
  78         boost::mutex::scoped_lock lock (_mutex);
  79         _queue.push_back (make_pair (encoded, frame));
  80         _condition.notify_all ();
  81 }
  82
  83 /** This method is not thread safe */
  84 void
  85 Writer::write (shared_ptr<const AudioBuffers> audio)
  86 {
  87         _sound_asset_writer->write (audio->data(), audio->frames());
  88 }
  89
  90 struct QueueSorter
  91 {
  92         bool operator() (pair<shared_ptr<const EncodedData>, int> const & a, pair<shared_ptr<const EncodedData>, int> const & b) {
  93                 return a.second < b.second;
  94         }
  95 };
  96
  97 void
  98 Writer::thread ()
  99 {
 100         while (1)
 101         {
 102                 boost::mutex::scoped_lock lock (_mutex);
 103
 104                 while (1) {
 105                         if (_finish ||
 106                             _queue.size() > _maximum_frames_in_memory ||
 107                             (!_queue.empty() && _queue.front().second == (_last_written_frame + 1))) {
 108
 109                                     break;
 110                             }
 111
 112                             TIMING ("writer sleeps with a queue of %1; %2 pending", _queue.size(), _pending.size());
 113                             _condition.wait (lock);
 114                             TIMING ("writer wakes with a queue of %1", _queue.size());
 115
 116                             _queue.sort (QueueSorter ());
 117                 }
 118
 119                 if (_finish && _queue.empty() && _pending.empty()) {
 120                         return;
 121                 }
 122
 123                 /* Write any frames that we can write; i.e. those that are in sequence */
 124                 while (!_queue.empty() && _queue.front().second == (_last_written_frame + 1)) {
 125                         pair<boost::shared_ptr<const EncodedData>, int> encoded = _queue.front ();
 126                         _queue.pop_front ();
 127
 128                         lock.unlock ();
 129                         _film->log()->log (String::compose ("Writer writes %1 to MXF", encoded.second));
 130                         if (encoded.first) {
 131                                 _picture_asset_writer->write (encoded.first->data(), encoded.first->size());
 132                                 encoded.first->write_hash (_film, encoded.second);
 133                                 _last_written = encoded.first;
 134                         } else {
 135                                 _picture_asset_writer->write (_last_written->data(), _last_written->size());
 136                                 _last_written->write_hash (_film, encoded.second);
 137                         }
 138                         lock.lock ();
 139
 140                         ++_last_written_frame;
 141                 }
 142
 143                 while (_queue.size() > _maximum_frames_in_memory) {
 144                         /* Too many frames in memory which can't yet be written to the stream.
 145                            Put some to disk.
 146                         */
 147
 148                         pair<boost::shared_ptr<const EncodedData>, int> encoded = _queue.back ();
 149                         _queue.pop_back ();
 150                         if (!encoded.first) {
 151                                 /* This is a `repeat-last' frame, so no need to write it to disk */
 152                                 continue;
 153                         }
 154
 155                         lock.unlock ();
 156                         _film->log()->log (String::compose ("Writer full (awaiting %1); pushes %2 to disk", _last_written_frame + 1, encoded.second));
 157                         encoded.first->write (_film, encoded.second);
 158                         lock.lock ();
 159
 160                         _pending.push_back (encoded.second);
 161                 }
 162
 163                 while (_queue.size() < _maximum_frames_in_memory && !_pending.empty()) {
 164                         /* We have some space in memory.  Fetch some frames back off disk. */
 165
 166                         _pending.sort ();
 167                         int const fetch = _pending.front ();
 168
 169                         lock.unlock ();
 170                         _film->log()->log (String::compose ("Writer pulls %1 back from disk", fetch));
 171                         shared_ptr<const EncodedData> encoded;
 172                         if (boost::filesystem::exists (_film->j2c_path (fetch, false))) {
 173                                 /* It's an actual frame (not a repeat-last); load it in */
 174                                 encoded.reset (new EncodedData (_film->j2c_path (fetch, false)));
 175                         }
 176                         lock.lock ();
 177
 178                         _queue.push_back (make_pair (encoded, fetch));
 179                         _pending.remove (fetch);
 180                 }
 181         }
 182
 183 }
 184
 185 void
 186 Writer::finish ()
 187 {
 188         if (!_thread) {
 189                 return;
 190         }
 191
 192         boost::mutex::scoped_lock lock (_mutex);
 193         _finish = true;
 194         _condition.notify_all ();
 195         lock.unlock ();
 196
 197         _thread->join ();
 198         delete _thread;
 199         _thread = 0;
 200
 201         _picture_asset_writer->finalize ();
 202
 203         if (_sound_asset_writer) {
 204                 _sound_asset_writer->finalize ();
 205         }
 206
 207         int const frames = _last_written_frame + 1;
 208         int const duration = frames - _film->trim_start() - _film->trim_end();
 209
 210         _film->set_dcp_intrinsic_duration (frames);
 211
 212         _picture_asset->set_entry_point (_film->trim_start ());
 213         _picture_asset->set_duration (duration);
 214
 215         /* Hard-link the video MXF into the DCP */
 216
 217         boost::filesystem::path from;
 218         from /= _film->video_mxf_dir();
 219         from /= _film->video_mxf_filename();
 220
 221         boost::filesystem::path to;
 222         to /= _film->dir (_film->dcp_name());
 223         to /= "video.mxf";
 224
 225         boost::filesystem::create_hard_link (from, to);
 226
 227         /* And update the asset */
 228
 229         _picture_asset->set_directory (_film->dir (_film->dcp_name ()));
 230         _picture_asset->set_file_name ("video.mxf");
 231
 232         if (_sound_asset) {
 233                 _sound_asset->set_entry_point (_film->trim_start ());
 234                 _sound_asset->set_duration (duration);
 235         }
 236
 237         libdcp::DCP dcp (_film->dir (_film->dcp_name()));
 238         DCPFrameRate dfr (_film->frames_per_second ());
 239
 240         shared_ptr<libdcp::CPL> cpl (
 241                 new libdcp::CPL (_film->dir (_film->dcp_name()), _film->dcp_name(), _film->dcp_content_type()->libdcp_kind (), frames, dfr.frames_per_second)
 242                 );
 243
 244         dcp.add_cpl (cpl);
 245
 246         cpl->add_reel (shared_ptr<libdcp::Reel> (new libdcp::Reel (
 247                                                          _picture_asset,
 248                                                          _sound_asset,
 249                                                          shared_ptr<libdcp::SubtitleAsset> ()
 250                                                          )
 251                                ));
 252
 253         dcp.write_xml ();
 254 }
 255
 256 /** Tell the writer that frame `f' should be a repeat of the frame before it */
 257 void
 258 Writer::repeat (int f)
 259 {
 260         boost::mutex::scoped_lock lock (_mutex);
 261         _queue.push_back (make_pair (shared_ptr<const EncodedData> (), f));
 262 }