libs/ardour/export_graph_builder.cc

   1 /*
   2   Copyright (C) 2008-2012 Paul Davis
   3   Author: Sakari Bergen
   4
   5   This program is free software; you can redistribute it and/or modify
   6   it under the terms of the GNU General Public License as published by
   7   the Free Software Foundation; either version 2 of the License, or
   8   (at your option) any later version.
   9
  10   This program is distributed in the hope that it will be useful,
  11   but WITHOUT ANY WARRANTY; without even the implied warranty of
  12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13   GNU General Public License for more details.
  14
  15   You should have received a copy of the GNU General Public License
  16   along with this program; if not, write to the Free Software
  17   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18
  19 */
  20
  21 #include "ardour/export_graph_builder.h"
  22
  23 #include <vector>
  24
  25 #include <glibmm/miscutils.h>
  26
  27 #include "audiographer/process_context.h"
  28 #include "audiographer/general/chunker.h"
  29 #include "audiographer/general/interleaver.h"
  30 #include "audiographer/general/normalizer.h"
  31 #include "audiographer/general/analyser.h"
  32 #include "audiographer/general/peak_reader.h"
  33 #include "audiographer/general/sample_format_converter.h"
  34 #include "audiographer/general/sr_converter.h"
  35 #include "audiographer/general/silence_trimmer.h"
  36 #include "audiographer/general/threader.h"
  37 #include "audiographer/sndfile/tmp_file.h"
  38 #include "audiographer/sndfile/sndfile_writer.h"
  39
  40 #include "ardour/audioengine.h"
  41 #include "ardour/export_channel_configuration.h"
  42 #include "ardour/export_filename.h"
  43 #include "ardour/export_format_specification.h"
  44 #include "ardour/export_timespan.h"
  45 #include "ardour/session_directory.h"
  46 #include "ardour/sndfile_helpers.h"
  47
  48 #include "pbd/file_utils.h"
  49 #include "pbd/cpus.h"
  50
  51 using namespace AudioGrapher;
  52 using std::string;
  53
  54 namespace ARDOUR {
  55
  56 ExportGraphBuilder::ExportGraphBuilder (Session const & session)
  57         : session (session)
  58         , thread_pool (hardware_concurrency())
  59 {
  60         process_buffer_frames = session.engine().samples_per_cycle();
  61 }
  62
  63 ExportGraphBuilder::~ExportGraphBuilder ()
  64 {
  65 }
  66
  67 int
  68 ExportGraphBuilder::process (framecnt_t frames, bool last_cycle)
  69 {
  70         assert(frames <= process_buffer_frames);
  71
  72         for (ChannelMap::iterator it = channels.begin(); it != channels.end(); ++it) {
  73                 Sample const * process_buffer = 0;
  74                 it->first->read (process_buffer, frames);
  75                 ConstProcessContext<Sample> context(process_buffer, frames, 1);
  76                 if (last_cycle) { context().set_flag (ProcessContext<Sample>::EndOfInput); }
  77                 it->second->process (context);
  78         }
  79
  80         return 0;
  81 }
  82
  83 bool
  84 ExportGraphBuilder::process_normalize ()
  85 {
  86         for (std::list<Normalizer *>::iterator it = normalizers.begin(); it != normalizers.end(); /* ++ in loop */) {
  87                 if ((*it)->process()) {
  88                         it = normalizers.erase (it);
  89                 } else {
  90                         ++it;
  91                 }
  92         }
  93
  94         return normalizers.empty();
  95 }
  96
  97 unsigned
  98 ExportGraphBuilder::get_normalize_cycle_count() const
  99 {
 100         unsigned max = 0;
 101         for (std::list<Normalizer *>::const_iterator it = normalizers.begin(); it != normalizers.end(); ++it) {
 102                 max = std::max(max, (*it)->get_normalize_cycle_count());
 103         }
 104         return max;
 105 }
 106
 107 void
 108 ExportGraphBuilder::reset ()
 109 {
 110         timespan.reset();
 111         channel_configs.clear ();
 112         channels.clear ();
 113         normalizers.clear ();
 114         analysis_map.clear();
 115 }
 116
 117 void
 118 ExportGraphBuilder::cleanup (bool remove_out_files/*=false*/)
 119 {
 120         ChannelConfigList::iterator iter = channel_configs.begin();
 121
 122         while (iter != channel_configs.end() ) {
 123                 iter->remove_children(remove_out_files);
 124                 iter = channel_configs.erase(iter);
 125         }
 126 }
 127
 128 void
 129 ExportGraphBuilder::set_current_timespan (boost::shared_ptr<ExportTimespan> span)
 130 {
 131         timespan = span;
 132 }
 133
 134 void
 135 ExportGraphBuilder::add_config (FileSpec const & config)
 136 {
 137         ExportChannelConfiguration::ChannelList const & channels =
 138                 config.channel_config->get_channels();
 139         for(ExportChannelConfiguration::ChannelList::const_iterator it = channels.begin();
 140             it != channels.end(); ++it) {
 141                 (*it)->set_max_buffer_size(process_buffer_frames);
 142         }
 143
 144         // If the sample rate is "session rate", change it to the real value.
 145         // However, we need to copy it to not change the config which is saved...
 146         FileSpec new_config (config);
 147         new_config.format.reset(new ExportFormatSpecification(*new_config.format, false));
 148         if(new_config.format->sample_rate() == ExportFormatBase::SR_Session) {
 149                 framecnt_t session_rate = session.nominal_frame_rate();
 150                 new_config.format->set_sample_rate(ExportFormatBase::nearest_sample_rate(session_rate));
 151         }
 152
 153
 154         if (!new_config.channel_config->get_split ()) {
 155                 add_split_config (new_config);
 156                 return;
 157         }
 158
 159         // Split channel configurations are split into several channel configurations,
 160         // each corresponding to a file, at this stage
 161         typedef std::list<boost::shared_ptr<ExportChannelConfiguration> > ConfigList;
 162         ConfigList file_configs;
 163         new_config.channel_config->configurations_for_files (file_configs);
 164
 165         unsigned chan = 1;
 166         for (ConfigList::iterator it = file_configs.begin(); it != file_configs.end(); ++it, ++chan) {
 167                 FileSpec copy = new_config;
 168                 copy.channel_config = *it;
 169
 170                 copy.filename.reset (new ExportFilename (*copy.filename));
 171                 copy.filename->include_channel = true;
 172                 copy.filename->set_channel (chan);
 173
 174                 add_split_config (copy);
 175         }
 176 }
 177
 178 void
 179 ExportGraphBuilder::get_analysis_results (AnalysisResults& results) {
 180         for (AnalysisMap::iterator i = analysis_map.begin(); i != analysis_map.end(); ++i) {
 181                 ExportAnalysisPtr p = i->second->result ();
 182                 if (p) {
 183                         results.insert (std::make_pair (i->first, p));
 184                 }
 185         }
 186 }
 187
 188 void
 189 ExportGraphBuilder::add_split_config (FileSpec const & config)
 190 {
 191         for (ChannelConfigList::iterator it = channel_configs.begin(); it != channel_configs.end(); ++it) {
 192                 if (*it == config) {
 193                         it->add_child (config);
 194                         return;
 195                 }
 196         }
 197
 198         // No duplicate channel config found, create new one
 199         channel_configs.push_back (new ChannelConfig (*this, config, channels));
 200 }
 201
 202 /* Encoder */
 203
 204 template <>
 205 boost::shared_ptr<AudioGrapher::Sink<Sample> >
 206 ExportGraphBuilder::Encoder::init (FileSpec const & new_config)
 207 {
 208         config = new_config;
 209         init_writer (float_writer);
 210         return float_writer;
 211 }
 212
 213 template <>
 214 boost::shared_ptr<AudioGrapher::Sink<int> >
 215 ExportGraphBuilder::Encoder::init (FileSpec const & new_config)
 216 {
 217         config = new_config;
 218         init_writer (int_writer);
 219         return int_writer;
 220 }
 221
 222 template <>
 223 boost::shared_ptr<AudioGrapher::Sink<short> >
 224 ExportGraphBuilder::Encoder::init (FileSpec const & new_config)
 225 {
 226         config = new_config;
 227         init_writer (short_writer);
 228         return short_writer;
 229 }
 230
 231 void
 232 ExportGraphBuilder::Encoder::add_child (FileSpec const & new_config)
 233 {
 234         filenames.push_back (new_config.filename);
 235 }
 236
 237 void
 238 ExportGraphBuilder::Encoder::destroy_writer (bool delete_out_file)
 239 {
 240         if (delete_out_file ) {
 241
 242                 if (float_writer) {
 243                         float_writer->close ();
 244                 }
 245
 246                 if (int_writer) {
 247                         int_writer->close ();
 248                 }
 249
 250                 if (short_writer) {
 251                         short_writer->close ();
 252                 }
 253
 254                 if (std::remove(writer_filename.c_str() ) != 0) {
 255                         std::cout << "Encoder::destroy_writer () : Error removing file: " << strerror(errno) << std::endl;
 256                 }
 257         }
 258
 259         float_writer.reset ();
 260         int_writer.reset ();
 261         short_writer.reset ();
 262 }
 263
 264 bool
 265 ExportGraphBuilder::Encoder::operator== (FileSpec const & other_config) const
 266 {
 267         return get_real_format (config) == get_real_format (other_config);
 268 }
 269
 270 int
 271 ExportGraphBuilder::Encoder::get_real_format (FileSpec const & config)
 272 {
 273         ExportFormatSpecification & format = *config.format;
 274         return format.format_id() | format.sample_format() | format.endianness();
 275 }
 276
 277 template<typename T>
 278 void
 279 ExportGraphBuilder::Encoder::init_writer (boost::shared_ptr<AudioGrapher::SndfileWriter<T> > & writer)
 280 {
 281         unsigned channels = config.channel_config->get_n_chans();
 282         int format = get_real_format (config);
 283         config.filename->set_channel_config(config.channel_config);
 284         writer_filename = config.filename->get_path (config.format);
 285
 286         writer.reset (new AudioGrapher::SndfileWriter<T> (writer_filename, format, channels, config.format->sample_rate(), config.broadcast_info));
 287         writer->FileWritten.connect_same_thread (copy_files_connection, boost::bind (&ExportGraphBuilder::Encoder::copy_files, this, _1));
 288 }
 289
 290 void
 291 ExportGraphBuilder::Encoder::copy_files (std::string orig_path)
 292 {
 293         while (filenames.size()) {
 294                 ExportFilenamePtr & filename = filenames.front();
 295                 PBD::copy_file (orig_path, filename->get_path (config.format).c_str());
 296                 filenames.pop_front();
 297         }
 298 }
 299
 300 /* SFC */
 301
 302 ExportGraphBuilder::SFC::SFC (ExportGraphBuilder &parent, FileSpec const & new_config, framecnt_t max_frames)
 303         : data_width(0)
 304 {
 305         config = new_config;
 306         data_width = sndfile_data_width (Encoder::get_real_format (config));
 307         unsigned channels = new_config.channel_config->get_n_chans();
 308         analyser.reset (new Analyser (config.format->sample_rate(), channels, max_frames,
 309                                 (framecnt_t) ceil (parent.timespan->get_length () * config.format->sample_rate () / (double) parent.session.nominal_frame_rate ())));
 310         parent.add_analyser (config.filename->get_path (config.format), analyser);
 311
 312         if (data_width == 8 || data_width == 16) {
 313                 short_converter = ShortConverterPtr (new SampleFormatConverter<short> (channels));
 314                 short_converter->init (max_frames, config.format->dither_type(), data_width);
 315                 add_child (config);
 316                 analyser->add_output (short_converter);
 317         } else if (data_width == 24 || data_width == 32) {
 318                 int_converter = IntConverterPtr (new SampleFormatConverter<int> (channels));
 319                 int_converter->init (max_frames, config.format->dither_type(), data_width);
 320                 add_child (config);
 321                 analyser->add_output (int_converter);
 322         } else {
 323                 int actual_data_width = 8 * sizeof(Sample);
 324                 float_converter = FloatConverterPtr (new SampleFormatConverter<Sample> (channels));
 325                 float_converter->init (max_frames, config.format->dither_type(), actual_data_width);
 326                 add_child (config);
 327                 analyser->add_output (float_converter);
 328         }
 329 }
 330
 331 ExportGraphBuilder::FloatSinkPtr
 332 ExportGraphBuilder::SFC::sink ()
 333 {
 334         return analyser;
 335 }
 336
 337 void
 338 ExportGraphBuilder::SFC::add_child (FileSpec const & new_config)
 339 {
 340         for (boost::ptr_list<Encoder>::iterator it = children.begin(); it != children.end(); ++it) {
 341                 if (*it == new_config) {
 342                         it->add_child (new_config);
 343                         return;
 344                 }
 345         }
 346
 347         children.push_back (new Encoder());
 348         Encoder & encoder = children.back();
 349
 350         if (data_width == 8 || data_width == 16) {
 351                 short_converter->add_output (encoder.init<short> (new_config));
 352         } else if (data_width == 24 || data_width == 32) {
 353                 int_converter->add_output (encoder.init<int> (new_config));
 354         } else {
 355                 float_converter->add_output (encoder.init<Sample> (new_config));
 356         }
 357 }
 358
 359 void
 360 ExportGraphBuilder::SFC::remove_children (bool remove_out_files)
 361 {
 362         boost::ptr_list<Encoder>::iterator iter = children.begin ();
 363
 364         while (iter != children.end() ) {
 365
 366                 if (remove_out_files) {
 367                         iter->destroy_writer(remove_out_files);
 368                 }
 369                 iter = children.erase (iter);
 370         }
 371 }
 372
 373 bool
 374 ExportGraphBuilder::SFC::operator== (FileSpec const & other_config) const
 375 {
 376         return config.format->sample_format() == other_config.format->sample_format();
 377 }
 378
 379 /* Normalizer */
 380
 381 ExportGraphBuilder::Normalizer::Normalizer (ExportGraphBuilder & parent, FileSpec const & new_config, framecnt_t /*max_frames*/)
 382         : parent (parent)
 383 {
 384         std::string tmpfile_path = parent.session.session_directory().export_path();
 385         tmpfile_path = Glib::build_filename(tmpfile_path, "XXXXXX");
 386         std::vector<char> tmpfile_path_buf(tmpfile_path.size() + 1);
 387         std::copy(tmpfile_path.begin(), tmpfile_path.end(), tmpfile_path_buf.begin());
 388         tmpfile_path_buf[tmpfile_path.size()] = '\0';
 389
 390         config = new_config;
 391         uint32_t const channels = config.channel_config->get_n_chans();
 392         max_frames_out = 4086 - (4086 % channels); // TODO good chunk size
 393
 394         buffer.reset (new AllocatingProcessContext<Sample> (max_frames_out, channels));
 395         peak_reader.reset (new PeakReader ());
 396         normalizer.reset (new AudioGrapher::Normalizer (config.format->normalize_target()));
 397         threader.reset (new Threader<Sample> (parent.thread_pool));
 398
 399         normalizer->alloc_buffer (max_frames_out);
 400         normalizer->add_output (threader);
 401
 402         int format = ExportFormatBase::F_RAW | ExportFormatBase::SF_Float;
 403         tmp_file.reset (new TmpFile<float> (&tmpfile_path_buf[0], format, channels, config.format->sample_rate()));
 404         tmp_file->FileWritten.connect_same_thread (post_processing_connection,
 405                                                    boost::bind (&Normalizer::start_post_processing, this));
 406
 407         add_child (new_config);
 408
 409         peak_reader->add_output (tmp_file);
 410 }
 411
 412 ExportGraphBuilder::FloatSinkPtr
 413 ExportGraphBuilder::Normalizer::sink ()
 414 {
 415         return peak_reader;
 416 }
 417
 418 void
 419 ExportGraphBuilder::Normalizer::add_child (FileSpec const & new_config)
 420 {
 421         for (boost::ptr_list<SFC>::iterator it = children.begin(); it != children.end(); ++it) {
 422                 if (*it == new_config) {
 423                         it->add_child (new_config);
 424                         return;
 425                 }
 426         }
 427
 428         children.push_back (new SFC (parent, new_config, max_frames_out));
 429         threader->add_output (children.back().sink());
 430 }
 431
 432 void
 433 ExportGraphBuilder::Normalizer::remove_children (bool remove_out_files)
 434 {
 435         boost::ptr_list<SFC>::iterator iter = children.begin ();
 436
 437         while (iter != children.end() ) {
 438                 iter->remove_children (remove_out_files);
 439                 iter = children.erase (iter);
 440         }
 441 }
 442
 443 bool
 444 ExportGraphBuilder::Normalizer::operator== (FileSpec const & other_config) const
 445 {
 446         return config.format->normalize() == other_config.format->normalize() &&
 447                 config.format->normalize_target() == other_config.format->normalize_target();
 448 }
 449
 450 unsigned
 451 ExportGraphBuilder::Normalizer::get_normalize_cycle_count() const
 452 {
 453         return static_cast<unsigned>(std::ceil(static_cast<float>(tmp_file->get_frames_written()) /
 454                                                max_frames_out));
 455 }
 456
 457 bool
 458 ExportGraphBuilder::Normalizer::process()
 459 {
 460         framecnt_t frames_read = tmp_file->read (*buffer);
 461         return frames_read != buffer->frames();
 462 }
 463
 464 void
 465 ExportGraphBuilder::Normalizer::start_post_processing()
 466 {
 467         normalizer->set_peak (peak_reader->get_peak());
 468         tmp_file->seek (0, SEEK_SET);
 469         tmp_file->add_output (normalizer);
 470         parent.normalizers.push_back (this);
 471 }
 472
 473 /* SRC */
 474
 475 ExportGraphBuilder::SRC::SRC (ExportGraphBuilder & parent, FileSpec const & new_config, framecnt_t max_frames)
 476         : parent (parent)
 477 {
 478         config = new_config;
 479         converter.reset (new SampleRateConverter (new_config.channel_config->get_n_chans()));
 480         ExportFormatSpecification & format = *new_config.format;
 481         converter->init (parent.session.nominal_frame_rate(), format.sample_rate(), format.src_quality());
 482         max_frames_out = converter->allocate_buffers (max_frames);
 483
 484         add_child (new_config);
 485 }
 486
 487 ExportGraphBuilder::FloatSinkPtr
 488 ExportGraphBuilder::SRC::sink ()
 489 {
 490         return converter;
 491 }
 492
 493 void
 494 ExportGraphBuilder::SRC::add_child (FileSpec const & new_config)
 495 {
 496         if (new_config.format->normalize()) {
 497                 add_child_to_list (new_config, normalized_children);
 498         } else {
 499                 add_child_to_list (new_config, children);
 500         }
 501 }
 502
 503 void
 504 ExportGraphBuilder::SRC::remove_children (bool remove_out_files)
 505 {
 506         boost::ptr_list<SFC>::iterator sfc_iter = children.begin();
 507
 508         while (sfc_iter != children.end() ) {
 509                 converter->remove_output (sfc_iter->sink() );
 510                 sfc_iter->remove_children (remove_out_files);
 511                 sfc_iter = children.erase (sfc_iter);
 512         }
 513
 514         boost::ptr_list<Normalizer>::iterator norm_iter = normalized_children.begin();
 515
 516         while (norm_iter != normalized_children.end() ) {
 517                 converter->remove_output (norm_iter->sink() );
 518                 norm_iter->remove_children (remove_out_files);
 519                 norm_iter = normalized_children.erase (norm_iter);
 520         }
 521
 522 }
 523
 524 template<typename T>
 525 void
 526 ExportGraphBuilder::SRC::add_child_to_list (FileSpec const & new_config, boost::ptr_list<T> & list)
 527 {
 528         for (typename boost::ptr_list<T>::iterator it = list.begin(); it != list.end(); ++it) {
 529                 if (*it == new_config) {
 530                         it->add_child (new_config);
 531                         return;
 532                 }
 533         }
 534
 535         list.push_back (new T (parent, new_config, max_frames_out));
 536         converter->add_output (list.back().sink ());
 537 }
 538
 539 bool
 540 ExportGraphBuilder::SRC::operator== (FileSpec const & other_config) const
 541 {
 542         return config.format->sample_rate() == other_config.format->sample_rate();
 543 }
 544
 545 /* SilenceHandler */
 546 ExportGraphBuilder::SilenceHandler::SilenceHandler (ExportGraphBuilder & parent, FileSpec const & new_config, framecnt_t max_frames)
 547         : parent (parent)
 548 {
 549         config = new_config;
 550         max_frames_in = max_frames;
 551         framecnt_t sample_rate = parent.session.nominal_frame_rate();
 552
 553         silence_trimmer.reset (new SilenceTrimmer<Sample>(max_frames_in));
 554         silence_trimmer->set_trim_beginning (config.format->trim_beginning());
 555         silence_trimmer->set_trim_end (config.format->trim_end());
 556
 557         framecnt_t sb = config.format->silence_beginning_at (parent.timespan->get_start(), sample_rate);
 558         framecnt_t se = config.format->silence_end_at (parent.timespan->get_end(), sample_rate);
 559
 560         silence_trimmer->add_silence_to_beginning (sb);
 561         silence_trimmer->add_silence_to_end (se);
 562
 563         add_child (new_config);
 564 }
 565
 566 ExportGraphBuilder::FloatSinkPtr
 567 ExportGraphBuilder::SilenceHandler::sink ()
 568 {
 569         return silence_trimmer;
 570 }
 571
 572 void
 573 ExportGraphBuilder::SilenceHandler::add_child (FileSpec const & new_config)
 574 {
 575         for (boost::ptr_list<SRC>::iterator it = children.begin(); it != children.end(); ++it) {
 576                 if (*it == new_config) {
 577                         it->add_child (new_config);
 578                         return;
 579                 }
 580         }
 581
 582         children.push_back (new SRC (parent, new_config, max_frames_in));
 583         silence_trimmer->add_output (children.back().sink());
 584 }
 585
 586 void
 587 ExportGraphBuilder::SilenceHandler::remove_children (bool remove_out_files)
 588 {
 589         boost::ptr_list<SRC>::iterator iter = children.begin();
 590
 591         while (iter != children.end() ) {
 592                 silence_trimmer->remove_output (iter->sink() );
 593                 iter->remove_children (remove_out_files);
 594                 iter = children.erase (iter);
 595         }
 596 }
 597
 598 bool
 599 ExportGraphBuilder::SilenceHandler::operator== (FileSpec const & other_config) const
 600 {
 601         ExportFormatSpecification & format = *config.format;
 602         ExportFormatSpecification & other_format = *other_config.format;
 603         return (format.trim_beginning() == other_format.trim_beginning()) &&
 604                 (format.trim_end() == other_format.trim_end()) &&
 605                 (format.silence_beginning_time() == other_format.silence_beginning_time()) &&
 606                 (format.silence_end_time() == other_format.silence_end_time());
 607 }
 608
 609 /* ChannelConfig */
 610
 611 ExportGraphBuilder::ChannelConfig::ChannelConfig (ExportGraphBuilder & parent, FileSpec const & new_config, ChannelMap & channel_map)
 612         : parent (parent)
 613 {
 614         typedef ExportChannelConfiguration::ChannelList ChannelList;
 615
 616         config = new_config;
 617
 618         framecnt_t max_frames = parent.session.engine().samples_per_cycle();
 619         interleaver.reset (new Interleaver<Sample> ());
 620         interleaver->init (new_config.channel_config->get_n_chans(), max_frames);
 621
 622         // Make the chunk size divisible by the channel count
 623         int chan_count = new_config.channel_config->get_n_chans();
 624         max_frames_out = 8192;
 625         if (chan_count > 0) {
 626                 max_frames_out -= max_frames_out % chan_count;
 627         }
 628         chunker.reset (new Chunker<Sample> (max_frames_out));
 629         interleaver->add_output(chunker);
 630
 631         ChannelList const & channel_list = config.channel_config->get_channels();
 632         unsigned chan = 0;
 633         for (ChannelList::const_iterator it = channel_list.begin(); it != channel_list.end(); ++it, ++chan) {
 634                 ChannelMap::iterator map_it = channel_map.find (*it);
 635                 if (map_it == channel_map.end()) {
 636                         std::pair<ChannelMap::iterator, bool> result_pair =
 637                                 channel_map.insert (std::make_pair (*it, IdentityVertexPtr (new IdentityVertex<Sample> ())));
 638                         assert (result_pair.second);
 639                         map_it = result_pair.first;
 640                 }
 641                 map_it->second->add_output (interleaver->input (chan));
 642         }
 643
 644         add_child (new_config);
 645 }
 646
 647 void
 648 ExportGraphBuilder::ChannelConfig::add_child (FileSpec const & new_config)
 649 {
 650         assert (*this == new_config);
 651
 652         for (boost::ptr_list<SilenceHandler>::iterator it = children.begin(); it != children.end(); ++it) {
 653                 if (*it == new_config) {
 654                         it->add_child (new_config);
 655                         return;
 656                 }
 657         }
 658
 659         children.push_back (new SilenceHandler (parent, new_config, max_frames_out));
 660         chunker->add_output (children.back().sink ());
 661 }
 662
 663 void
 664 ExportGraphBuilder::ChannelConfig::remove_children (bool remove_out_files)
 665 {
 666         boost::ptr_list<SilenceHandler>::iterator iter = children.begin();
 667
 668         while(iter != children.end() ) {
 669
 670                 chunker->remove_output (iter->sink ());
 671                 iter->remove_children (remove_out_files);
 672                 iter = children.erase(iter);
 673         }
 674 }
 675
 676 bool
 677 ExportGraphBuilder::ChannelConfig::operator== (FileSpec const & other_config) const
 678 {
 679         return config.channel_config == other_config.channel_config;
 680 }
 681
 682 } // namespace ARDOUR