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