src/lib/encoder.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/encoder.h
  21  *  @brief Parent class for classes which can encode video and audio frames.
  22  */
  23
  24 #include <iostream>
  25 #include <boost/filesystem.hpp>
  26 #include <boost/lexical_cast.hpp>
  27 #include <libdcp/picture_asset.h>
  28 #include "encoder.h"
  29 #include "util.h"
  30 #include "options.h"
  31 #include "film.h"
  32 #include "log.h"
  33 #include "exceptions.h"
  34 #include "filter.h"
  35 #include "config.h"
  36 #include "dcp_video_frame.h"
  37 #include "server.h"
  38 #include "format.h"
  39 #include "cross.h"
  40 #include "writer.h"
  41
  42 using std::pair;
  43 using std::string;
  44 using std::stringstream;
  45 using std::vector;
  46 using std::list;
  47 using std::cout;
  48 using std::make_pair;
  49 using namespace boost;
  50
  51 int const Encoder::_history_size = 25;
  52
  53 /** @param f Film that we are encoding.
  54  *  @param o Options.
  55  */
  56 Encoder::Encoder (shared_ptr<Film> f)
  57         : _film (f)
  58         , _video_frames_in (0)
  59         , _video_frames_out (0)
  60 #ifdef HAVE_SWRESAMPLE
  61         , _swr_context (0)
  62 #endif
  63         , _have_a_real_frame (false)
  64         , _terminate (false)
  65 {
  66
  67 }
  68
  69 Encoder::~Encoder ()
  70 {
  71         terminate_threads ();
  72         if (_writer) {
  73                 _writer->finish ();
  74         }
  75 }
  76
  77 void
  78 Encoder::process_begin ()
  79 {
  80         if (_film->audio_stream() && _film->audio_stream()->sample_rate() != _film->target_audio_sample_rate()) {
  81 #ifdef HAVE_SWRESAMPLE
  82
  83                 stringstream s;
  84                 s << "Will resample audio from " << _film->audio_stream()->sample_rate() << " to " << _film->target_audio_sample_rate();
  85                 _film->log()->log (s.str ());
  86
  87                 /* We will be using planar float data when we call the resampler */
  88                 _swr_context = swr_alloc_set_opts (
  89                         0,
  90                         _film->audio_stream()->channel_layout(),
  91                         AV_SAMPLE_FMT_FLTP,
  92                         _film->target_audio_sample_rate(),
  93                         _film->audio_stream()->channel_layout(),
  94                         AV_SAMPLE_FMT_FLTP,
  95                         _film->audio_stream()->sample_rate(),
  96                         0, 0
  97                         );
  98
  99                 swr_init (_swr_context);
 100 #else
 101                 throw EncodeError ("Cannot resample audio as libswresample is not present");
 102 #endif
 103         } else {
 104 #ifdef HAVE_SWRESAMPLE
 105                 _swr_context = 0;
 106 #endif
 107         }
 108
 109         for (int i = 0; i < Config::instance()->num_local_encoding_threads (); ++i) {
 110                 _threads.push_back (new boost::thread (boost::bind (&Encoder::encoder_thread, this, (ServerDescription *) 0)));
 111         }
 112
 113         vector<ServerDescription*> servers = Config::instance()->servers ();
 114
 115         for (vector<ServerDescription*>::iterator i = servers.begin(); i != servers.end(); ++i) {
 116                 for (int j = 0; j < (*i)->threads (); ++j) {
 117                         _threads.push_back (new boost::thread (boost::bind (&Encoder::encoder_thread, this, *i)));
 118                 }
 119         }
 120
 121         _writer.reset (new Writer (_film));
 122 }
 123
 124
 125 void
 126 Encoder::process_end ()
 127 {
 128 #if HAVE_SWRESAMPLE
 129         if (_film->audio_stream() && _film->audio_stream()->channels() && _swr_context) {
 130
 131                 shared_ptr<AudioBuffers> out (new AudioBuffers (_film->audio_stream()->channels(), 256));
 132
 133                 while (1) {
 134                         int const frames = swr_convert (_swr_context, (uint8_t **) out->data(), 256, 0, 0);
 135
 136                         if (frames < 0) {
 137                                 throw EncodeError ("could not run sample-rate converter");
 138                         }
 139
 140                         if (frames == 0) {
 141                                 break;
 142                         }
 143
 144                         out->set_frames (frames);
 145                         _writer->write (out);
 146                 }
 147
 148                 swr_free (&_swr_context);
 149         }
 150 #endif
 151
 152         boost::mutex::scoped_lock lock (_mutex);
 153
 154         _film->log()->log ("Clearing queue of " + lexical_cast<string> (_queue.size ()));
 155
 156         /* Keep waking workers until the queue is empty */
 157         while (!_queue.empty ()) {
 158                 _film->log()->log ("Waking with " + lexical_cast<string> (_queue.size ()), Log::VERBOSE);
 159                 _condition.notify_all ();
 160                 _condition.wait (lock);
 161         }
 162
 163         lock.unlock ();
 164
 165         terminate_threads ();
 166
 167         _film->log()->log ("Mopping up " + lexical_cast<string> (_queue.size()));
 168
 169         /* The following sequence of events can occur in the above code:
 170              1. a remote worker takes the last image off the queue
 171              2. the loop above terminates
 172              3. the remote worker fails to encode the image and puts it back on the queue
 173              4. the remote worker is then terminated by terminate_threads
 174
 175              So just mop up anything left in the queue here.
 176         */
 177
 178         for (list<shared_ptr<DCPVideoFrame> >::iterator i = _queue.begin(); i != _queue.end(); ++i) {
 179                 _film->log()->log (String::compose ("Encode left-over frame %1", (*i)->frame ()));
 180                 try {
 181                         _writer->write ((*i)->encode_locally(), (*i)->frame ());
 182                         frame_done ();
 183                 } catch (std::exception& e) {
 184                         _film->log()->log (String::compose ("Local encode failed (%1)", e.what ()));
 185                 }
 186         }
 187
 188         _writer->finish ();
 189         _writer.reset ();
 190 }
 191
 192 /** @return an estimate of the current number of frames we are encoding per second,
 193  *  or 0 if not known.
 194  */
 195 float
 196 Encoder::current_frames_per_second () const
 197 {
 198         boost::mutex::scoped_lock lock (_history_mutex);
 199         if (int (_time_history.size()) < _history_size) {
 200                 return 0;
 201         }
 202
 203         struct timeval now;
 204         gettimeofday (&now, 0);
 205
 206         return _history_size / (seconds (now) - seconds (_time_history.back ()));
 207 }
 208
 209 /** @return Number of video frames that have been sent out */
 210 int
 211 Encoder::video_frames_out () const
 212 {
 213         boost::mutex::scoped_lock (_history_mutex);
 214         return _video_frames_out;
 215 }
 216
 217 /** Should be called when a frame has been encoded successfully.
 218  *  @param n Source frame index.
 219  */
 220 void
 221 Encoder::frame_done ()
 222 {
 223         boost::mutex::scoped_lock lock (_history_mutex);
 224
 225         struct timeval tv;
 226         gettimeofday (&tv, 0);
 227         _time_history.push_front (tv);
 228         if (int (_time_history.size()) > _history_size) {
 229                 _time_history.pop_back ();
 230         }
 231 }
 232
 233 void
 234 Encoder::process_video (shared_ptr<Image> image, bool same, boost::shared_ptr<Subtitle> sub)
 235 {
 236         DCPFrameRate dfr (_film->frames_per_second ());
 237
 238         if (dfr.skip && (_video_frames_in % 2)) {
 239                 ++_video_frames_in;
 240                 return;
 241         }
 242
 243         boost::mutex::scoped_lock lock (_mutex);
 244
 245         /* Wait until the queue has gone down a bit */
 246         while (_queue.size() >= _threads.size() * 2 && !_terminate) {
 247                 TIMING ("decoder sleeps with queue of %1", _queue.size());
 248                 _condition.wait (lock);
 249                 TIMING ("decoder wakes with queue of %1", _queue.size());
 250         }
 251
 252         if (_terminate) {
 253                 return;
 254         }
 255
 256         if (_writer->can_fake_write (_video_frames_out)) {
 257                 _writer->fake_write (_video_frames_out);
 258                 _have_a_real_frame = false;
 259                 frame_done ();
 260         } else if (same && _have_a_real_frame) {
 261                 /* Use the last frame that we encoded. */
 262                 _writer->repeat (_video_frames_out);
 263                 frame_done ();
 264         } else {
 265                 /* Queue this new frame for encoding */
 266                 pair<string, string> const s = Filter::ffmpeg_strings (_film->filters());
 267                 TIMING ("adding to queue of %1", _queue.size ());
 268                 _queue.push_back (boost::shared_ptr<DCPVideoFrame> (
 269                                           new DCPVideoFrame (
 270                                                   image, sub, _film->format()->dcp_size(), _film->format()->dcp_padding (_film),
 271                                                   _film->subtitle_offset(), _film->subtitle_scale(),
 272                                                   _film->scaler(), _video_frames_out, _film->frames_per_second(), s.second,
 273                                                   _film->colour_lut(), _film->j2k_bandwidth(),
 274                                                   _film->log()
 275                                                   )
 276                                           ));
 277
 278                 _condition.notify_all ();
 279                 _have_a_real_frame = true;
 280         }
 281
 282         ++_video_frames_in;
 283         ++_video_frames_out;
 284
 285         if (dfr.repeat) {
 286                 _writer->repeat (_video_frames_out);
 287                 ++_video_frames_out;
 288                 frame_done ();
 289         }
 290 }
 291
 292 void
 293 Encoder::process_audio (shared_ptr<AudioBuffers> data)
 294 {
 295 #if HAVE_SWRESAMPLE
 296         /* Maybe sample-rate convert */
 297         if (_swr_context) {
 298
 299                 /* Compute the resampled frames count and add 32 for luck */
 300                 int const max_resampled_frames = ceil ((int64_t) data->frames() * _film->target_audio_sample_rate() / _film->audio_stream()->sample_rate()) + 32;
 301
 302                 shared_ptr<AudioBuffers> resampled (new AudioBuffers (_film->audio_stream()->channels(), max_resampled_frames));
 303
 304                 /* Resample audio */
 305                 int const resampled_frames = swr_convert (
 306                         _swr_context, (uint8_t **) resampled->data(), max_resampled_frames, (uint8_t const **) data->data(), data->frames()
 307                         );
 308
 309                 if (resampled_frames < 0) {
 310                         throw EncodeError ("could not run sample-rate converter");
 311                 }
 312
 313                 resampled->set_frames (resampled_frames);
 314
 315                 /* And point our variables at the resampled audio */
 316                 data = resampled;
 317         }
 318 #endif
 319
 320         if (_film->audio_channels() == 1) {
 321                 /* We need to switch things around so that the mono channel is on
 322                    the centre channel of a 5.1 set (with other channels silent).
 323                 */
 324
 325                 shared_ptr<AudioBuffers> b (new AudioBuffers (6, data->frames ()));
 326                 b->make_silent (libdcp::LEFT);
 327                 b->make_silent (libdcp::RIGHT);
 328                 memcpy (b->data()[libdcp::CENTRE], data->data()[0], data->frames() * sizeof(float));
 329                 b->make_silent (libdcp::LFE);
 330                 b->make_silent (libdcp::LS);
 331                 b->make_silent (libdcp::RS);
 332
 333                 data = b;
 334         }
 335
 336         _writer->write (data);
 337 }
 338
 339 void
 340 Encoder::terminate_threads ()
 341 {
 342         boost::mutex::scoped_lock lock (_mutex);
 343         _terminate = true;
 344         _condition.notify_all ();
 345         lock.unlock ();
 346
 347         for (list<boost::thread *>::iterator i = _threads.begin(); i != _threads.end(); ++i) {
 348                 (*i)->join ();
 349                 delete *i;
 350         }
 351 }
 352
 353 void
 354 Encoder::encoder_thread (ServerDescription* server)
 355 {
 356         /* Number of seconds that we currently wait between attempts
 357            to connect to the server; not relevant for localhost
 358            encodings.
 359         */
 360         int remote_backoff = 0;
 361
 362         while (1) {
 363
 364                 TIMING ("encoder thread %1 sleeps", boost::this_thread::get_id());
 365                 boost::mutex::scoped_lock lock (_mutex);
 366                 while (_queue.empty () && !_terminate) {
 367                         _condition.wait (lock);
 368                 }
 369
 370                 if (_terminate) {
 371                         return;
 372                 }
 373
 374                 TIMING ("encoder thread %1 wakes with queue of %2", boost::this_thread::get_id(), _queue.size());
 375                 boost::shared_ptr<DCPVideoFrame> vf = _queue.front ();
 376                 _film->log()->log (String::compose ("Encoder thread %1 pops frame %2 from queue", boost::this_thread::get_id(), vf->frame()), Log::VERBOSE);
 377                 _queue.pop_front ();
 378
 379                 lock.unlock ();
 380
 381                 shared_ptr<EncodedData> encoded;
 382
 383                 if (server) {
 384                         try {
 385                                 encoded = vf->encode_remotely (server);
 386
 387                                 if (remote_backoff > 0) {
 388                                         _film->log()->log (String::compose ("%1 was lost, but now she is found; removing backoff", server->host_name ()));
 389                                 }
 390
 391                                 /* This job succeeded, so remove any backoff */
 392                                 remote_backoff = 0;
 393
 394                         } catch (std::exception& e) {
 395                                 if (remote_backoff < 60) {
 396                                         /* back off more */
 397                                         remote_backoff += 10;
 398                                 }
 399                                 _film->log()->log (
 400                                         String::compose (
 401                                                 "Remote encode of %1 on %2 failed (%3); thread sleeping for %4s",
 402                                                 vf->frame(), server->host_name(), e.what(), remote_backoff)
 403                                         );
 404                         }
 405
 406                 } else {
 407                         try {
 408                                 TIMING ("encoder thread %1 begins local encode of %2", boost::this_thread::get_id(), vf->frame());
 409                                 encoded = vf->encode_locally ();
 410                                 TIMING ("encoder thread %1 finishes local encode of %2", boost::this_thread::get_id(), vf->frame());
 411                         } catch (std::exception& e) {
 412                                 _film->log()->log (String::compose ("Local encode failed (%1)", e.what ()));
 413                         }
 414                 }
 415
 416                 if (encoded) {
 417                         _writer->write (encoded, vf->frame ());
 418                         frame_done ();
 419                 } else {
 420                         lock.lock ();
 421                         _film->log()->log (
 422                                 String::compose ("Encoder thread %1 pushes frame %2 back onto queue after failure", boost::this_thread::get_id(), vf->frame())
 423                                 );
 424                         _queue.push_front (vf);
 425                         lock.unlock ();
 426                 }
 427
 428                 if (remote_backoff > 0) {
 429                         dvdomatic_sleep (remote_backoff);
 430                 }
 431
 432                 lock.lock ();
 433                 _condition.notify_all ();
 434         }
 435 }