src/lib/encoder.cc

   1 /*
   2     Copyright (C) 2012-2015 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 "encoder.h"
  25 #include "util.h"
  26 #include "film.h"
  27 #include "log.h"
  28 #include "config.h"
  29 #include "dcp_video.h"
  30 #include "server.h"
  31 #include "cross.h"
  32 #include "writer.h"
  33 #include "server_finder.h"
  34 #include "player.h"
  35 #include "player_video.h"
  36 #include "server_description.h"
  37 #include "compose.hpp"
  38 #include <libcxml/cxml.h>
  39 #include <boost/foreach.hpp>
  40 #include <iostream>
  41
  42 #include "i18n.h"
  43
  44 #define LOG_GENERAL(...) _film->log()->log (String::compose (__VA_ARGS__), LogEntry::TYPE_GENERAL);
  45 #define LOG_GENERAL_NC(...) _film->log()->log (__VA_ARGS__, LogEntry::TYPE_GENERAL);
  46 #define LOG_ERROR(...) _film->log()->log (String::compose (__VA_ARGS__), LogEntry::TYPE_ERROR);
  47 #define LOG_TIMING(...) _film->log()->log (String::compose (__VA_ARGS__), LogEntry::TYPE_TIMING);
  48
  49 using std::list;
  50 using std::cout;
  51 using boost::shared_ptr;
  52 using boost::weak_ptr;
  53 using boost::optional;
  54 using dcp::Data;
  55
  56 int const Encoder::_history_size = 25;
  57
  58 /** @param f Film that we are encoding */
  59 Encoder::Encoder (shared_ptr<const Film> film, shared_ptr<Writer> writer)
  60         : _film (film)
  61         , _position (0)
  62         , _terminate_enqueue (false)
  63         , _terminate_encoding (false)
  64         , _writer (writer)
  65 {
  66         servers_list_changed ();
  67 }
  68
  69 Encoder::~Encoder ()
  70 {
  71         terminate_threads ();
  72
  73         boost::mutex::scoped_lock lm (_queue_mutex);
  74         _terminate_enqueue = true;
  75         _full_condition.notify_all ();
  76         _empty_condition.notify_all ();
  77 }
  78
  79 void
  80 Encoder::begin ()
  81 {
  82         if (!ServerFinder::instance()->disabled ()) {
  83                 _server_found_connection = ServerFinder::instance()->ServersListChanged.connect (boost::bind (&Encoder::servers_list_changed, this));
  84         }
  85 }
  86
  87 void
  88 Encoder::end ()
  89 {
  90         boost::mutex::scoped_lock lock (_queue_mutex);
  91
  92         LOG_GENERAL (N_("Clearing queue of %1"), _queue.size ());
  93
  94         /* Keep waking workers until the queue is empty */
  95         while (!_queue.empty ()) {
  96                 rethrow ();
  97                 _empty_condition.notify_all ();
  98                 _full_condition.wait (lock);
  99         }
 100
 101         lock.unlock ();
 102
 103         LOG_GENERAL_NC (N_("Terminating encoder threads"));
 104
 105         terminate_threads ();
 106
 107         LOG_GENERAL (N_("Mopping up %1"), _queue.size());
 108
 109         /* The following sequence of events can occur in the above code:
 110              1. a remote worker takes the last image off the queue
 111              2. the loop above terminates
 112              3. the remote worker fails to encode the image and puts it back on the queue
 113              4. the remote worker is then terminated by terminate_threads
 114
 115              So just mop up anything left in the queue here.
 116         */
 117
 118         for (list<shared_ptr<DCPVideo> >::iterator i = _queue.begin(); i != _queue.end(); ++i) {
 119                 LOG_GENERAL (N_("Encode left-over frame %1"), (*i)->index ());
 120                 try {
 121                         _writer->write (
 122                                 (*i)->encode_locally (boost::bind (&Log::dcp_log, _film->log().get(), _1, _2)),
 123                                 (*i)->index (),
 124                                 (*i)->eyes ()
 125                                 );
 126                         frame_done ();
 127                 } catch (std::exception& e) {
 128                         LOG_ERROR (N_("Local encode failed (%1)"), e.what ());
 129                 }
 130         }
 131 }
 132
 133 /** @return an estimate of the current number of frames we are encoding per second,
 134  *  or 0 if not known.
 135  */
 136 float
 137 Encoder::current_encoding_rate () const
 138 {
 139         boost::mutex::scoped_lock lock (_state_mutex);
 140         if (int (_time_history.size()) < _history_size) {
 141                 return 0;
 142         }
 143
 144         struct timeval now;
 145         gettimeofday (&now, 0);
 146
 147         return _history_size / (seconds (now) - seconds (_time_history.back ()));
 148 }
 149
 150 /** @return Number of video frames that have been sent out */
 151 int
 152 Encoder::video_frames_out () const
 153 {
 154         boost::mutex::scoped_lock (_state_mutex);
 155         return _position;
 156 }
 157
 158 /** Should be called when a frame has been encoded successfully.
 159  *  @param n Source frame index.
 160  */
 161 void
 162 Encoder::frame_done ()
 163 {
 164         boost::mutex::scoped_lock lock (_state_mutex);
 165
 166         struct timeval tv;
 167         gettimeofday (&tv, 0);
 168         _time_history.push_front (tv);
 169         if (int (_time_history.size()) > _history_size) {
 170                 _time_history.pop_back ();
 171         }
 172 }
 173
 174 /** Called to start encoding of the next video frame in the DCP.  This is called in order,
 175  *  so each time the supplied frame is the one after the previous one.
 176  *  pv represents one video frame, and could be empty if there is nothing to encode
 177  *  for this DCP frame.
 178  */
 179 void
 180 Encoder::encode (list<shared_ptr<PlayerVideo> > pv)
 181 {
 182         BOOST_FOREACH (shared_ptr<PlayerVideo> i, pv) {
 183                 enqueue (i);
 184         }
 185         ++_position;
 186 }
 187
 188 void
 189 Encoder::enqueue (shared_ptr<PlayerVideo> pv)
 190 {
 191         _waker.nudge ();
 192
 193         size_t threads = 0;
 194         {
 195                 boost::mutex::scoped_lock threads_lock (_threads_mutex);
 196                 threads = _threads.size ();
 197         }
 198
 199         boost::mutex::scoped_lock queue_lock (_queue_mutex);
 200
 201         /* XXX: discard 3D here if required */
 202
 203         /* Wait until the queue has gone down a bit */
 204         while (_queue.size() >= threads * 2 && !_terminate_enqueue) {
 205                 LOG_TIMING ("decoder-sleep queue=%1", _queue.size());
 206                 _full_condition.wait (queue_lock);
 207                 LOG_TIMING ("decoder-wake queue=%1", _queue.size());
 208         }
 209
 210         if (_terminate_enqueue) {
 211                 return;
 212         }
 213
 214         _writer->rethrow ();
 215         /* Re-throw any exception raised by one of our threads.  If more
 216            than one has thrown an exception, only one will be rethrown, I think;
 217            but then, if that happens something has gone badly wrong.
 218         */
 219         rethrow ();
 220
 221         if (_writer->can_fake_write (_position)) {
 222                 /* We can fake-write this frame */
 223                 _writer->fake_write (_position, pv->eyes ());
 224                 frame_done ();
 225         } else if (pv->has_j2k ()) {
 226                 /* This frame already has JPEG2000 data, so just write it */
 227                 _writer->write (pv->j2k(), _position, pv->eyes ());
 228         } else if (_last_player_video && _writer->can_repeat(_position) && pv->same (_last_player_video)) {
 229                 _writer->repeat (_position, pv->eyes ());
 230         } else {
 231                 /* Queue this new frame for encoding */
 232                 LOG_TIMING ("add-frame-to-queue queue=%1", _queue.size ());
 233                 _queue.push_back (shared_ptr<DCPVideo> (
 234                                           new DCPVideo (
 235                                                   pv,
 236                                                   _position,
 237                                                   _film->video_frame_rate(),
 238                                                   _film->j2k_bandwidth(),
 239                                                   _film->resolution(),
 240                                                   _film->log()
 241                                                   )
 242                                           ));
 243
 244                 /* The queue might not be empty any more, so notify anything which is
 245                    waiting on that.
 246                 */
 247                 _empty_condition.notify_all ();
 248         }
 249
 250         _last_player_video = pv;
 251 }
 252
 253 void
 254 Encoder::terminate_threads ()
 255 {
 256         {
 257                 boost::mutex::scoped_lock queue_lock (_queue_mutex);
 258                 _terminate_encoding = true;
 259         }
 260
 261         boost::mutex::scoped_lock threads_lock (_threads_mutex);
 262
 263         for (list<boost::thread *>::iterator i = _threads.begin(); i != _threads.end(); ++i) {
 264                 (*i)->interrupt ();
 265                 if ((*i)->joinable ()) {
 266                         (*i)->join ();
 267                 }
 268                 delete *i;
 269         }
 270
 271         _threads.clear ();
 272         _terminate_encoding = false;
 273 }
 274
 275 void
 276 Encoder::encoder_thread (optional<ServerDescription> server)
 277 try
 278 {
 279         if (server) {
 280                 LOG_TIMING ("start-encoder-thread thread=%1 server=%2", boost::this_thread::get_id (), server->host_name ());
 281         } else {
 282                 LOG_TIMING ("start-encoder-thread thread=%1 server=localhost", boost::this_thread::get_id ());
 283         }
 284
 285         /* Number of seconds that we currently wait between attempts
 286            to connect to the server; not relevant for localhost
 287            encodings.
 288         */
 289         int remote_backoff = 0;
 290
 291         while (true) {
 292
 293                 LOG_TIMING ("encoder-sleep thread=%1", boost::this_thread::get_id());
 294                 boost::mutex::scoped_lock lock (_queue_mutex);
 295                 while (_queue.empty () && !_terminate_encoding) {
 296                         _empty_condition.wait (lock);
 297                 }
 298
 299                 if (_terminate_encoding) {
 300                         return;
 301                 }
 302
 303                 LOG_TIMING ("encoder-wake thread=%1 queue=%2", boost::this_thread::get_id(), _queue.size());
 304                 shared_ptr<DCPVideo> vf = _queue.front ();
 305                 LOG_TIMING ("encoder-pop thread=%1 frame=%2 eyes=%3", boost::this_thread::get_id(), vf->index(), vf->eyes ());
 306                 _queue.pop_front ();
 307
 308                 lock.unlock ();
 309
 310                 optional<Data> encoded;
 311
 312                 /* We need to encode this input */
 313                 if (server) {
 314                         try {
 315                                 encoded = vf->encode_remotely (server.get ());
 316
 317                                 if (remote_backoff > 0) {
 318                                         LOG_GENERAL ("%1 was lost, but now she is found; removing backoff", server->host_name ());
 319                                 }
 320
 321                                 /* This job succeeded, so remove any backoff */
 322                                 remote_backoff = 0;
 323
 324                         } catch (std::exception& e) {
 325                                 if (remote_backoff < 60) {
 326                                         /* back off more */
 327                                         remote_backoff += 10;
 328                                 }
 329                                 LOG_ERROR (
 330                                         N_("Remote encode of %1 on %2 failed (%3); thread sleeping for %4s"),
 331                                         vf->index(), server->host_name(), e.what(), remote_backoff
 332                                         );
 333                         }
 334
 335                 } else {
 336                         try {
 337                                 LOG_TIMING ("start-local-encode thread=%1 frame=%2", boost::this_thread::get_id(), vf->index());
 338                                 encoded = vf->encode_locally (boost::bind (&Log::dcp_log, _film->log().get(), _1, _2));
 339                                 LOG_TIMING ("finish-local-encode thread=%1 frame=%2", boost::this_thread::get_id(), vf->index());
 340                         } catch (std::exception& e) {
 341                                 LOG_ERROR (N_("Local encode failed (%1)"), e.what ());
 342                                 throw;
 343                         }
 344                 }
 345
 346                 if (encoded) {
 347                         _writer->write (encoded.get(), vf->index (), vf->eyes ());
 348                         frame_done ();
 349                 } else {
 350                         lock.lock ();
 351                         LOG_GENERAL (N_("[%1] Encoder thread pushes frame %2 back onto queue after failure"), boost::this_thread::get_id(), vf->index());
 352                         _queue.push_front (vf);
 353                         lock.unlock ();
 354                 }
 355
 356                 if (remote_backoff > 0) {
 357                         boost::this_thread::sleep_for (boost::chrono::seconds (remote_backoff));
 358                 }
 359
 360                 /* The queue might not be full any more, so notify anything that is waiting on that */
 361                 lock.lock ();
 362                 _full_condition.notify_all ();
 363         }
 364 }
 365 catch (...)
 366 {
 367         store_current ();
 368         /* Wake anything waiting on _full_condition so it can see the exception */
 369         _full_condition.notify_all ();
 370 }
 371
 372 void
 373 Encoder::servers_list_changed ()
 374 {
 375         terminate_threads ();
 376
 377         /* XXX: could re-use threads */
 378
 379         boost::mutex::scoped_lock lm (_threads_mutex);
 380
 381         if (!Config::instance()->only_servers_encode ()) {
 382                 for (int i = 0; i < Config::instance()->num_local_encoding_threads (); ++i) {
 383                         _threads.push_back (new boost::thread (boost::bind (&Encoder::encoder_thread, this, optional<ServerDescription> ())));
 384                 }
 385         }
 386
 387         BOOST_FOREACH (ServerDescription i, ServerFinder::instance()->servers ()) {
 388                 LOG_GENERAL (N_("Adding %1 worker threads for remote %2"), i.threads(), i.host_name ());
 389                 for (int j = 0; j < i.threads(); ++j) {
 390                         _threads.push_back (new boost::thread (boost::bind (&Encoder::encoder_thread, this, i)));
 391                 }
 392         }
 393
 394         _writer->set_encoder_threads (_threads.size ());
 395 }