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_encoder (false)
  65 {
  66
  67 }
  68
  69 Encoder::~Encoder ()
  70 {
  71         terminate_worker_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                 _worker_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                         _worker_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 (_worker_mutex);
 153
 154         _film->log()->log ("Clearing queue of " + lexical_cast<string> (_encode_queue.size ()));
 155
 156         /* Keep waking workers until the queue is empty */
 157         while (!_encode_queue.empty ()) {
 158                 _film->log()->log ("Waking with " + lexical_cast<string> (_encode_queue.size ()), Log::VERBOSE);
 159                 _worker_condition.notify_all ();
 160                 _worker_condition.wait (lock);
 161         }
 162
 163         lock.unlock ();
 164
 165         terminate_worker_threads ();
 166
 167         _film->log()->log ("Mopping up " + lexical_cast<string> (_encode_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_worker_threads
 174
 175              So just mop up anything left in the queue here.
 176         */
 177
 178         for (list<shared_ptr<DCPVideoFrame> >::iterator i = _encode_queue.begin(); i != _encode_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 (_worker_mutex);
 244
 245         /* Wait until the queue has gone down a bit */
 246         while (_encode_queue.size() >= _worker_threads.size() * 2 && !_terminate_encoder) {
 247                 TIMING ("decoder sleeps with queue of %1", _encode_queue.size());
 248                 _worker_condition.wait (lock);
 249                 TIMING ("decoder wakes with queue of %1", _encode_queue.size());
 250         }
 251
 252         if (_terminate_encoder) {
 253                 return;
 254         }
 255
 256         if (same && _have_a_real_frame) {
 257                 /* Use the last frame that we encoded. */
 258                 _writer->repeat (_video_frames_out);
 259                 frame_done ();
 260         } else {
 261                 /* Queue this new frame for encoding */
 262                 pair<string, string> const s = Filter::ffmpeg_strings (_film->filters());
 263                 TIMING ("adding to queue of %1", _encode_queue.size ());
 264                 _encode_queue.push_back (boost::shared_ptr<DCPVideoFrame> (
 265                                           new DCPVideoFrame (
 266                                                   image, sub, _film->format()->dcp_size(), _film->format()->dcp_padding (_film),
 267                                                   _film->subtitle_offset(), _film->subtitle_scale(),
 268                                                   _film->scaler(), _video_frames_out, _film->frames_per_second(), s.second,
 269                                                   _film->colour_lut(), _film->j2k_bandwidth(),
 270                                                   _film->log()
 271                                                   )
 272                                           ));
 273
 274                 _worker_condition.notify_all ();
 275                 _have_a_real_frame = true;
 276         }
 277
 278         ++_video_frames_in;
 279         ++_video_frames_out;
 280
 281         if (dfr.repeat) {
 282                 _writer->repeat (_video_frames_out);
 283                 ++_video_frames_out;
 284                 frame_done ();
 285         }
 286 }
 287
 288 void
 289 Encoder::process_audio (shared_ptr<AudioBuffers> data)
 290 {
 291 #if HAVE_SWRESAMPLE
 292         /* Maybe sample-rate convert */
 293         if (_swr_context) {
 294
 295                 /* Compute the resampled frames count and add 32 for luck */
 296                 int const max_resampled_frames = ceil ((int64_t) data->frames() * _film->target_audio_sample_rate() / _film->audio_stream()->sample_rate()) + 32;
 297
 298                 shared_ptr<AudioBuffers> resampled (new AudioBuffers (_film->audio_stream()->channels(), max_resampled_frames));
 299
 300                 /* Resample audio */
 301                 int const resampled_frames = swr_convert (
 302                         _swr_context, (uint8_t **) resampled->data(), max_resampled_frames, (uint8_t const **) data->data(), data->frames()
 303                         );
 304
 305                 if (resampled_frames < 0) {
 306                         throw EncodeError ("could not run sample-rate converter");
 307                 }
 308
 309                 resampled->set_frames (resampled_frames);
 310
 311                 /* And point our variables at the resampled audio */
 312                 data = resampled;
 313         }
 314 #endif
 315
 316         if (_film->audio_channels() == 1) {
 317                 /* We need to switch things around so that the mono channel is on
 318                    the centre channel of a 5.1 set (with other channels silent).
 319                 */
 320
 321                 shared_ptr<AudioBuffers> b (new AudioBuffers (6, data->frames ()));
 322                 b->make_silent (libdcp::LEFT);
 323                 b->make_silent (libdcp::RIGHT);
 324                 memcpy (b->data()[libdcp::CENTRE], data->data()[0], data->frames() * sizeof(float));
 325                 b->make_silent (libdcp::LFE);
 326                 b->make_silent (libdcp::LS);
 327                 b->make_silent (libdcp::RS);
 328
 329                 data = b;
 330         }
 331
 332         _writer->write (data);
 333 }
 334
 335 void
 336 Encoder::terminate_worker_threads ()
 337 {
 338         boost::mutex::scoped_lock lock (_worker_mutex);
 339         _terminate_encoder = true;
 340         _worker_condition.notify_all ();
 341         lock.unlock ();
 342
 343         for (list<boost::thread *>::iterator i = _worker_threads.begin(); i != _worker_threads.end(); ++i) {
 344                 (*i)->join ();
 345                 delete *i;
 346         }
 347 }
 348
 349 void
 350 Encoder::encoder_thread (ServerDescription* server)
 351 {
 352         /* Number of seconds that we currently wait between attempts
 353            to connect to the server; not relevant for localhost
 354            encodings.
 355         */
 356         int remote_backoff = 0;
 357
 358         while (1) {
 359
 360                 TIMING ("encoder thread %1 sleeps", boost::this_thread::get_id());
 361                 boost::mutex::scoped_lock lock (_worker_mutex);
 362                 while (_encode_queue.empty () && !_terminate_encoder) {
 363                         _worker_condition.wait (lock);
 364                 }
 365
 366                 if (_terminate_encoder) {
 367                         return;
 368                 }
 369
 370                 TIMING ("encoder thread %1 wakes with queue of %2", boost::this_thread::get_id(), _encode_queue.size());
 371                 boost::shared_ptr<DCPVideoFrame> vf = _encode_queue.front ();
 372                 _film->log()->log (String::compose ("Encoder thread %1 pops frame %2 from queue", boost::this_thread::get_id(), vf->frame()), Log::VERBOSE);
 373                 _encode_queue.pop_front ();
 374
 375                 lock.unlock ();
 376
 377                 shared_ptr<EncodedData> encoded;
 378
 379                 if (server) {
 380                         try {
 381                                 encoded = vf->encode_remotely (server);
 382
 383                                 if (remote_backoff > 0) {
 384                                         _film->log()->log (String::compose ("%1 was lost, but now she is found; removing backoff", server->host_name ()));
 385                                 }
 386
 387                                 /* This job succeeded, so remove any backoff */
 388                                 remote_backoff = 0;
 389
 390                         } catch (std::exception& e) {
 391                                 if (remote_backoff < 60) {
 392                                         /* back off more */
 393                                         remote_backoff += 10;
 394                                 }
 395                                 _film->log()->log (
 396                                         String::compose (
 397                                                 "Remote encode of %1 on %2 failed (%3); thread sleeping for %4s",
 398                                                 vf->frame(), server->host_name(), e.what(), remote_backoff)
 399                                         );
 400                         }
 401
 402                 } else {
 403                         try {
 404                                 TIMING ("encoder thread %1 begins local encode of %2", boost::this_thread::get_id(), vf->frame());
 405                                 encoded = vf->encode_locally ();
 406                                 TIMING ("encoder thread %1 finishes local encode of %2", boost::this_thread::get_id(), vf->frame());
 407                         } catch (std::exception& e) {
 408                                 _film->log()->log (String::compose ("Local encode failed (%1)", e.what ()));
 409                         }
 410                 }
 411
 412                 if (encoded) {
 413                         _writer->write (encoded, vf->frame ());
 414                         frame_done ();
 415                 } else {
 416                         lock.lock ();
 417                         _film->log()->log (
 418                                 String::compose ("Encoder thread %1 pushes frame %2 back onto queue after failure", boost::this_thread::get_id(), vf->frame())
 419                                 );
 420                         _encode_queue.push_front (vf);
 421                         lock.unlock ();
 422                 }
 423
 424                 if (remote_backoff > 0) {
 425                         dvdomatic_sleep (remote_backoff);
 426                 }
 427
 428                 lock.lock ();
 429                 _worker_condition.notify_all ();
 430         }
 431 }