libs/ardour/source.cc

   1 /*
   2     Copyright (C) 2000 Paul Davis
   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     $Id$
  19 */
  20
  21 #include <sys/stat.h>
  22 #include <unistd.h>
  23 #include <fcntl.h>
  24 #include <poll.h>
  25 #include <float.h>
  26 #include <cerrno>
  27 #include <ctime>
  28 #include <cmath>
  29 #include <iomanip>
  30 #include <algorithm>
  31
  32 #include <pbd/lockmonitor.h>
  33 #include <pbd/xml++.h>
  34 #include <pbd/pthread_utils.h>
  35
  36 #include <ardour/source.h>
  37
  38 #include "i18n.h"
  39
  40 using std::min;
  41 using std::max;
  42
  43 using namespace ARDOUR;
  44 using namespace PBD;
  45
  46 sigc::signal<void,Source *> Source::SourceCreated;
  47 pthread_t                    Source::peak_thread;
  48 bool                         Source::have_peak_thread = false;
  49 vector<Source*>              Source::pending_peak_sources;
  50 PBD::Lock                    Source::pending_peak_sources_lock;
  51 int                          Source::peak_request_pipe[2];
  52
  53 bool Source::_build_missing_peakfiles = false;
  54 bool Source::_build_peakfiles = false;
  55
  56 Source::Source (bool announce)
  57 {
  58         _id = ARDOUR::new_id();
  59         _use_cnt = 0;
  60         _peaks_built = false;
  61         next_peak_clear_should_notify = true;
  62         _timestamp = 0;
  63         _read_data_count = 0;
  64         _write_data_count = 0;
  65 }
  66
  67 Source::Source (const XMLNode& node)
  68 {
  69         _use_cnt = 0;
  70         _peaks_built = false;
  71         next_peak_clear_should_notify = true;
  72         _timestamp = 0;
  73         _read_data_count = 0;
  74         _write_data_count = 0;
  75
  76         if (set_state (node)) {
  77                 throw failed_constructor();
  78         }
  79 }
  80
  81 Source::~Source ()
  82 {
  83 }
  84
  85 XMLNode&
  86 Source::get_state ()
  87 {
  88         XMLNode *node = new XMLNode ("Source");
  89         char buf[64];
  90
  91         node->add_property ("name", _name);
  92         snprintf (buf, sizeof(buf)-1, "%" PRIu64, _id);
  93         node->add_property ("id", buf);
  94
  95         if (_timestamp != 0) {
  96                 snprintf (buf, sizeof (buf), "%ld", _timestamp);
  97                 node->add_property ("timestamp", buf);
  98         }
  99
 100         if (_captured_for.length()) {
 101                 node->add_property ("captured-for", _captured_for);
 102         }
 103
 104         return *node;
 105 }
 106
 107 int
 108 Source::set_state (const XMLNode& node)
 109 {
 110         const XMLProperty* prop;
 111
 112         if ((prop = node.property ("name")) != 0) {
 113                 _name = prop->value();
 114         } else {
 115                 return -1;
 116         }
 117
 118         if ((prop = node.property ("id")) != 0) {
 119                 sscanf (prop->value().c_str(), "%" PRIu64, &_id);
 120         } else {
 121                 return -1;
 122         }
 123
 124         if ((prop = node.property ("timestamp")) != 0) {
 125                 sscanf (prop->value().c_str(), "%ld", &_timestamp);
 126         }
 127
 128         if ((prop = node.property ("captured-for")) != 0) {
 129                 _captured_for = prop->value();
 130         }
 131
 132         return 0;
 133 }
 134
 135 /***********************************************************************
 136   PEAK FILE STUFF
 137  ***********************************************************************/
 138
 139 void*
 140 Source::peak_thread_work (void* arg)
 141 {
 142         PBD::ThreadCreated (pthread_self(), X_("Peak"));
 143         struct pollfd pfd[1];
 144
 145         LockMonitor lm (pending_peak_sources_lock, __LINE__, __FILE__);
 146
 147         while (true) {
 148
 149                 pfd[0].fd = peak_request_pipe[0];
 150                 pfd[0].events = POLLIN|POLLERR|POLLHUP;
 151
 152                 pthread_mutex_unlock (pending_peak_sources_lock.mutex());
 153
 154                 if (poll (pfd, 1, -1) < 0) {
 155
 156                         if (errno == EINTR) {
 157                                 pthread_mutex_lock (pending_peak_sources_lock.mutex());
 158                                 continue;
 159                         }
 160
 161                         error << string_compose (_("poll on peak request pipe failed (%1)"),
 162                                           strerror (errno))
 163                               << endmsg;
 164                         break;
 165                 }
 166
 167                 if (pfd[0].revents & ~POLLIN) {
 168                         error << _("Error on peak thread request pipe") << endmsg;
 169                         break;
 170                 }
 171
 172                 if (pfd[0].revents & POLLIN) {
 173
 174                         char req;
 175
 176                         /* empty the pipe of all current requests */
 177
 178                         while (1) {
 179                                 size_t nread = ::read (peak_request_pipe[0], &req, sizeof (req));
 180
 181                                 if (nread == 1) {
 182                                         switch ((PeakRequest::Type) req) {
 183
 184                                         case PeakRequest::Build:
 185                                                 break;
 186
 187                                         case PeakRequest::Quit:
 188                                                 pthread_exit_pbd (0);
 189                                                 /*NOTREACHED*/
 190                                                 break;
 191
 192                                         default:
 193                                                 break;
 194                                         }
 195
 196                                 } else if (nread == 0) {
 197                                         break;
 198                                 } else if (errno == EAGAIN) {
 199                                         break;
 200                                 } else {
 201                                         fatal << _("Error reading from peak request pipe") << endmsg;
 202                                         /*NOTREACHED*/
 203                                 }
 204                         }
 205                 }
 206
 207                 pthread_mutex_lock (pending_peak_sources_lock.mutex());
 208
 209                 while (!pending_peak_sources.empty()) {
 210
 211                         Source* s = pending_peak_sources.front();
 212                         pending_peak_sources.erase (pending_peak_sources.begin());
 213
 214                         pthread_mutex_unlock (pending_peak_sources_lock.mutex());
 215                         s->build_peaks();
 216                         pthread_mutex_lock (pending_peak_sources_lock.mutex());
 217                 }
 218         }
 219
 220         pthread_exit_pbd (0);
 221         /*NOTREACHED*/
 222         return 0;
 223 }
 224
 225 int
 226 Source::start_peak_thread ()
 227 {
 228         if (!_build_peakfiles) {
 229                 return 0;
 230         }
 231
 232         if (pipe (peak_request_pipe)) {
 233                 error << string_compose(_("Cannot create transport request signal pipe (%1)"), strerror (errno)) << endmsg;
 234                 return -1;
 235         }
 236
 237         if (fcntl (peak_request_pipe[0], F_SETFL, O_NONBLOCK)) {
 238                 error << string_compose(_("UI: cannot set O_NONBLOCK on peak request pipe (%1)"), strerror (errno)) << endmsg;
 239                 return -1;
 240         }
 241
 242         if (fcntl (peak_request_pipe[1], F_SETFL, O_NONBLOCK)) {
 243                 error << string_compose(_("UI: cannot set O_NONBLOCK on peak request pipe (%1)"), strerror (errno)) << endmsg;
 244                 return -1;
 245         }
 246
 247         if (pthread_create_and_store ("peak file builder", &peak_thread, 0, peak_thread_work, 0)) {
 248                 error << _("Source: could not create peak thread") << endmsg;
 249                 return -1;
 250         }
 251
 252         have_peak_thread = true;
 253         return 0;
 254 }
 255
 256 void
 257 Source::stop_peak_thread ()
 258 {
 259         if (!have_peak_thread) {
 260                 return;
 261         }
 262
 263         void* status;
 264
 265         char c = (char) PeakRequest::Quit;
 266         ::write (peak_request_pipe[1], &c, 1);
 267         pthread_join (peak_thread, &status);
 268 }
 269
 270 void
 271 Source::queue_for_peaks (Source& source)
 272 {
 273         if (have_peak_thread) {
 274
 275                 LockMonitor lm (pending_peak_sources_lock, __LINE__, __FILE__);
 276
 277                 source.next_peak_clear_should_notify = true;
 278
 279                 if (find (pending_peak_sources.begin(),
 280                           pending_peak_sources.end(),
 281                           &source) == pending_peak_sources.end()) {
 282                         pending_peak_sources.push_back (&source);
 283                 }
 284
 285                 char c = (char) PeakRequest::Build;
 286                 ::write (peak_request_pipe[1], &c, 1);
 287         }
 288 }
 289
 290 void Source::clear_queue_for_peaks ()
 291 {
 292         /* this is done to cancel a group of running peak builds */
 293         if (have_peak_thread) {
 294                 LockMonitor lm (pending_peak_sources_lock, __LINE__, __FILE__);
 295                 pending_peak_sources.clear ();
 296         }
 297 }
 298
 299
 300 bool
 301 Source::peaks_ready (sigc::slot<void> the_slot, sigc::connection& conn) const
 302 {
 303         bool ret;
 304         LockMonitor lm (_lock, __LINE__, __FILE__);
 305
 306         /* check to see if the peak data is ready. if not
 307            connect the slot while still holding the lock.
 308         */
 309
 310         if (!(ret = _peaks_built)) {
 311                 conn = PeaksReady.connect (the_slot);
 312         }
 313
 314         return ret;
 315 }
 316
 317 int
 318 Source::rename_peakfile (string newpath)
 319 {
 320         /* caller must hold _lock */
 321
 322         string oldpath = peakpath;
 323
 324         if (access (oldpath.c_str(), F_OK) == 0) {
 325                 if (rename (oldpath.c_str(), newpath.c_str()) != 0) {
 326                         error << string_compose (_("cannot rename peakfile for %1 from %2 to %3 (%4)"), _name, oldpath, newpath, strerror (errno)) << endmsg;
 327                         return -1;
 328                 }
 329         }
 330
 331         peakpath = newpath;
 332
 333         return 0;
 334 }
 335
 336 int
 337 Source::initialize_peakfile (bool newfile, string audio_path)
 338 {
 339         struct stat statbuf;
 340
 341         peakpath = peak_path (audio_path);
 342
 343         if (newfile) {
 344
 345                 if (!_build_peakfiles) {
 346                         return 0;
 347                 }
 348
 349                 _peaks_built = false;
 350
 351         } else {
 352
 353                 if (stat (peakpath.c_str(), &statbuf)) {
 354                         if (errno != ENOENT) {
 355                                 /* it exists in the peaks dir, but there is some kind of error */
 356
 357                                 error << string_compose(_("Source: cannot stat peakfile \"%1\""), peakpath) << endmsg;
 358                                 return -1;
 359                         }
 360
 361                 } else {
 362
 363                         /* we found it in the peaks dir */
 364                 }
 365
 366                 if (statbuf.st_size == 0) {
 367                         _peaks_built = false;
 368                 } else {
 369                         // Check if the audio file has changed since the peakfile was built.
 370                         struct stat stat_file;
 371                         int err = stat (audio_path.c_str(), &stat_file);
 372
 373                         if (!err && stat_file.st_mtime > statbuf.st_mtime){
 374                                 _peaks_built = false;
 375                         } else {
 376                                 _peaks_built = true;
 377                         }
 378                 }
 379         }
 380
 381         if (!newfile && !_peaks_built && _build_missing_peakfiles && _build_peakfiles) {
 382                 build_peaks_from_scratch ();
 383         }
 384
 385         return 0;
 386 }
 387
 388 int
 389 Source::read_peaks (PeakData *peaks, jack_nframes_t npeaks, jack_nframes_t start, jack_nframes_t cnt, double samples_per_visual_peak) const
 390 {
 391         LockMonitor lm (_lock, __LINE__, __FILE__);
 392         double scale;
 393         double expected_peaks;
 394         PeakData::PeakDatum xmax;
 395         PeakData::PeakDatum xmin;
 396         int32_t to_read;
 397         uint32_t nread;
 398         jack_nframes_t zero_fill = 0;
 399         int ret = -1;
 400         PeakData* staging = 0;
 401         Sample* raw_staging = 0;
 402         char * workbuf = 0;
 403         int peakfile = -1;
 404
 405         expected_peaks = (cnt / (double) frames_per_peak);
 406         scale = npeaks/expected_peaks;
 407
 408 #if 0
 409         cerr << "======>RP: npeaks = " << npeaks
 410              << " start = " << start
 411              << " cnt = " << cnt
 412              << " len = " << _length
 413              << "   samples_per_visual_peak =" << samples_per_visual_peak
 414              << " expected was " << expected_peaks << " ... scale = " << scale
 415              << " PD ptr = " << peaks
 416              <<endl;
 417
 418 #endif
 419
 420         /* fix for near-end-of-file conditions */
 421
 422         if (cnt > _length - start) {
 423                 // cerr << "too close to end @ " << _length << " given " << start << " + " << cnt << endl;
 424                 cnt = _length - start;
 425                 jack_nframes_t old = npeaks;
 426                 npeaks = min ((jack_nframes_t) floor (cnt / samples_per_visual_peak), npeaks);
 427                 zero_fill = old - npeaks;
 428         }
 429
 430         // cerr << "actual npeaks = " << npeaks << " zf = " << zero_fill << endl;
 431
 432         if (npeaks == cnt) {
 433
 434                 // cerr << "RAW DATA\n";
 435
 436                 /* no scaling at all, just get the sample data and duplicate it for
 437                    both max and min peak values.
 438                 */
 439
 440                 Sample* raw_staging = new Sample[cnt];
 441                 workbuf = new char[cnt*4];
 442
 443                 if (read_unlocked (raw_staging, start, cnt, workbuf) != cnt) {
 444                         error << _("cannot read sample data for unscaled peak computation") << endmsg;
 445                         return -1;
 446                 }
 447
 448                 for (jack_nframes_t i = 0; i < npeaks; ++i) {
 449                         peaks[i].max = raw_staging[i];
 450                         peaks[i].min = raw_staging[i];
 451                 }
 452
 453                 delete [] raw_staging;
 454                 delete [] workbuf;
 455                 return 0;
 456         }
 457
 458         if (scale == 1.0) {
 459
 460                 off_t first_peak_byte = (start / frames_per_peak) * sizeof (PeakData);
 461
 462                 /* open, read, close */
 463
 464                 if ((peakfile = ::open (peakpath.c_str(), O_RDWR|O_CREAT, 0664)) < 0) {
 465                         error << string_compose(_("Source: cannot open peakpath \"%1\" (%2)"), peakpath, strerror (errno)) << endmsg;
 466                         return -1;
 467                 }
 468
 469                 // cerr << "DIRECT PEAKS\n";
 470
 471                 nread = ::pread (peakfile, peaks, sizeof (PeakData)* npeaks, first_peak_byte);
 472                 close (peakfile);
 473
 474                 if (nread != sizeof (PeakData) * npeaks) {
 475                         cerr << "Source["
 476                              << _name
 477                              << "]: cannot read peaks from peakfile! (read only "
 478                              << nread
 479                              << " not "
 480                              << npeaks
 481                               << "at sample "
 482                              << start
 483                              << " = byte "
 484                              << first_peak_byte
 485                              << ')'
 486                              << endl;
 487                         return -1;
 488                 }
 489
 490                 if (zero_fill) {
 491                         memset (&peaks[npeaks], 0, sizeof (PeakData) * zero_fill);
 492                 }
 493
 494                 return 0;
 495         }
 496
 497
 498         jack_nframes_t tnp;
 499
 500         if (scale < 1.0) {
 501
 502                 // cerr << "DOWNSAMPLE\n";
 503
 504                 /* the caller wants:
 505
 506                     - more frames-per-peak (lower resolution) than the peakfile, or to put it another way,
 507                     - less peaks than the peakfile holds for the same range
 508
 509                     So, read a block into a staging area, and then downsample from there.
 510
 511                     to avoid confusion, I'll refer to the requested peaks as visual_peaks and the peakfile peaks as stored_peaks
 512                 */
 513
 514                 const uint32_t chunksize = (uint32_t) min (expected_peaks, 4096.0);
 515
 516                 staging = new PeakData[chunksize];
 517
 518                 /* compute the rounded up frame position  */
 519
 520                 jack_nframes_t current_frame = start;
 521                 jack_nframes_t current_stored_peak = (jack_nframes_t) ceil (current_frame / (double) frames_per_peak);
 522                 uint32_t       next_visual_peak  = (uint32_t) ceil (current_frame / samples_per_visual_peak);
 523                 double         next_visual_peak_frame = next_visual_peak * samples_per_visual_peak;
 524                 uint32_t       stored_peak_before_next_visual_peak = (jack_nframes_t) next_visual_peak_frame / frames_per_peak;
 525                 uint32_t       nvisual_peaks = 0;
 526                 uint32_t       stored_peaks_read = 0;
 527                 uint32_t       i = 0;
 528
 529                 /* handle the case where the initial visual peak is on a pixel boundary */
 530
 531                 current_stored_peak = min (current_stored_peak, stored_peak_before_next_visual_peak);
 532
 533                 /* open ... close during out: handling */
 534
 535                 if ((peakfile = ::open (peakpath.c_str(), O_RDWR|O_CREAT, 0664)) < 0) {
 536                         error << string_compose(_("Source: cannot open peakpath \"%1\" (%2)"), peakpath, strerror (errno)) << endmsg;
 537                         return 0;
 538                 }
 539
 540                 while (nvisual_peaks < npeaks) {
 541
 542                         if (i == stored_peaks_read) {
 543
 544                                 uint32_t       start_byte = current_stored_peak * sizeof(PeakData);
 545                                 tnp = min ((_length/frames_per_peak - current_stored_peak), (jack_nframes_t) expected_peaks);
 546                                 to_read = min (chunksize, tnp);
 547
 548                                 off_t fend = lseek (peakfile, 0, SEEK_END);
 549
 550                                 if ((nread = ::pread (peakfile, staging, sizeof (PeakData) * to_read, start_byte))
 551                                     != sizeof (PeakData) * to_read) {
 552                                         cerr << "Source["
 553                                              << _name
 554                                              << "]: cannot read peak data from peakfile ("
 555                                              << (nread / sizeof(PeakData))
 556                                              << " peaks instead of "
 557                                              << to_read
 558                                              << ") ("
 559                                              << strerror (errno)
 560                                              << ')'
 561                                              << " at start_byte = " << start_byte
 562                                              << " _length = " << _length << " versus len = " << fend
 563                                              << " expected maxpeaks = " << (_length - current_frame)/frames_per_peak
 564                                              << " npeaks was " << npeaks
 565                                              << endl;
 566                                         goto out;
 567                                 }
 568
 569                                 i = 0;
 570                                 stored_peaks_read = nread / sizeof(PeakData);
 571                         }
 572
 573                         xmax = -1.0;
 574                         xmin = 1.0;
 575
 576                         while ((i < stored_peaks_read) && (current_stored_peak <= stored_peak_before_next_visual_peak)) {
 577
 578                                 xmax = max (xmax, staging[i].max);
 579                                 xmin = min (xmin, staging[i].min);
 580                                 ++i;
 581                                 ++current_stored_peak;
 582                                 --expected_peaks;
 583                         }
 584
 585                         peaks[nvisual_peaks].max = xmax;
 586                         peaks[nvisual_peaks].min = xmin;
 587                         ++nvisual_peaks;
 588                         ++next_visual_peak;
 589
 590                         //next_visual_peak_frame = min ((next_visual_peak * samples_per_visual_peak), (next_visual_peak_frame+samples_per_visual_peak) );
 591                         next_visual_peak_frame =  min ((double) start+cnt, (next_visual_peak_frame+samples_per_visual_peak) );
 592                         stored_peak_before_next_visual_peak = (uint32_t) next_visual_peak_frame / frames_per_peak;
 593                 }
 594
 595                 if (zero_fill) {
 596                         memset (&peaks[npeaks], 0, sizeof (PeakData) * zero_fill);
 597                 }
 598
 599                 ret = 0;
 600
 601         } else {
 602
 603                 // cerr << "UPSAMPLE\n";
 604
 605                 /* the caller wants
 606
 607                      - less frames-per-peak (more resolution)
 608                      - more peaks than stored in the Peakfile
 609
 610                    So, fetch data from the raw source, and generate peak
 611                    data on the fly.
 612                 */
 613
 614                 jack_nframes_t frames_read = 0;
 615                 jack_nframes_t current_frame = start;
 616                 jack_nframes_t i = 0;
 617                 jack_nframes_t nvisual_peaks = 0;
 618                 jack_nframes_t chunksize = (jack_nframes_t) min (cnt, (jack_nframes_t) 4096);
 619                 raw_staging = new Sample[chunksize];
 620                 workbuf = new char[chunksize *4];
 621
 622                 jack_nframes_t frame_pos = start;
 623                 double pixel_pos = floor (frame_pos / samples_per_visual_peak);
 624                 double next_pixel_pos = ceil (frame_pos / samples_per_visual_peak);
 625                 double pixels_per_frame = 1.0 / samples_per_visual_peak;
 626
 627                 xmin = 1.0;
 628                 xmax = -1.0;
 629
 630                 while (nvisual_peaks < npeaks) {
 631
 632                         if (i == frames_read) {
 633
 634                                 to_read = min (chunksize, (_length - current_frame));
 635
 636                                 if ((frames_read = read_unlocked (raw_staging, current_frame, to_read, workbuf)) < 0) {
 637                                         error << string_compose(_("Source[%1]: peak read - cannot read %2 samples at offset %3")
 638                                                          , _name, to_read, current_frame)
 639                                               << endmsg;
 640                                         goto out;
 641                                 }
 642
 643                                 i = 0;
 644                         }
 645
 646                         xmax = max (xmax, raw_staging[i]);
 647                         xmin = min (xmin, raw_staging[i]);
 648                         ++i;
 649                         ++current_frame;
 650                         pixel_pos += pixels_per_frame;
 651
 652                         if (pixel_pos >= next_pixel_pos) {
 653
 654                                 peaks[nvisual_peaks].max = xmax;
 655                                 peaks[nvisual_peaks].min = xmin;
 656                                 ++nvisual_peaks;
 657                                 xmin = 1.0;
 658                                 xmax = -1.0;
 659
 660                                 next_pixel_pos = ceil (pixel_pos + 0.5);
 661                         }
 662                 }
 663
 664                 if (zero_fill) {
 665                         memset (&peaks[npeaks], 0, sizeof (PeakData) * zero_fill);
 666                 }
 667
 668                 ret = 0;
 669         }
 670
 671   out:
 672         if (peakfile >= 0) {
 673                 close (peakfile);
 674         }
 675
 676         if (staging) {
 677                 delete [] staging;
 678         }
 679
 680         if (raw_staging) {
 681                 delete [] raw_staging;
 682         }
 683
 684         if (workbuf) {
 685                 delete [] workbuf;
 686         }
 687
 688         return ret;
 689 }
 690
 691 #undef DEBUG_PEAK_BUILD
 692
 693 int
 694 Source::build_peaks ()
 695 {
 696         vector<PeakBuildRecord*> built;
 697         int status = -1;
 698         bool pr_signal = false;
 699         list<PeakBuildRecord*> copy;
 700
 701         {
 702                 LockMonitor lm (_lock, __LINE__, __FILE__);
 703                 copy = pending_peak_builds;
 704                 pending_peak_builds.clear ();
 705         }
 706
 707 #ifdef DEBUG_PEAK_BUILD
 708         cerr << "build peaks with " << copy.size() << " requests pending\n";
 709 #endif
 710
 711         for (list<PeakBuildRecord *>::iterator i = copy.begin(); i != copy.end(); ++i) {
 712
 713                 if ((status = do_build_peak ((*i)->frame, (*i)->cnt)) != 0) {
 714                         unlink (peakpath.c_str());
 715                         break;
 716                 }
 717                 built.push_back (new PeakBuildRecord (*(*i)));
 718                 delete *i;
 719         }
 720
 721         {
 722                 LockMonitor lm (_lock, __LINE__, __FILE__);
 723
 724                 if (status == 0) {
 725                         _peaks_built = true;
 726
 727                         if (next_peak_clear_should_notify) {
 728                                 next_peak_clear_should_notify = false;
 729                                 pr_signal = true;
 730                         }
 731                 }
 732         }
 733
 734         if (status == 0) {
 735                 for (vector<PeakBuildRecord *>::iterator i = built.begin(); i != built.end(); ++i) {
 736                         PeakRangeReady ((*i)->frame, (*i)->cnt); /* EMIT SIGNAL */
 737                         delete *i;
 738                 }
 739
 740                 if (pr_signal) {
 741                         PeaksReady (); /* EMIT SIGNAL */
 742                 }
 743         }
 744
 745         return status;
 746 }
 747
 748 int
 749 Source::do_build_peak (jack_nframes_t first_frame, jack_nframes_t cnt)
 750 {
 751         jack_nframes_t current_frame;
 752         Sample buf[frames_per_peak];
 753         Sample xmin, xmax;
 754         uint32_t  peaki;
 755         PeakData* peakbuf;
 756         char * workbuf = 0;
 757         jack_nframes_t frames_read;
 758         jack_nframes_t frames_to_read;
 759         off_t first_peak_byte;
 760         int peakfile = -1;
 761         int ret = -1;
 762
 763 #ifdef DEBUG_PEAK_BUILD
 764         cerr << pthread_self() << ": " << _name << ": building peaks for " << first_frame << " to " << first_frame + cnt - 1 << endl;
 765 #endif
 766
 767         first_peak_byte = (first_frame / frames_per_peak) * sizeof (PeakData);
 768
 769 #ifdef DEBUG_PEAK_BUILD
 770         cerr << "seeking to " << first_peak_byte << " before writing new peak data\n";
 771 #endif
 772
 773         current_frame = first_frame;
 774         peakbuf = new PeakData[(cnt/frames_per_peak)+1];
 775         peaki = 0;
 776
 777         workbuf = new char[max(frames_per_peak, cnt) * 4];
 778
 779         if ((peakfile = ::open (peakpath.c_str(), O_RDWR|O_CREAT, 0664)) < 0) {
 780                 error << string_compose(_("Source: cannot open peakpath \"%1\" (%2)"), peakpath, strerror (errno)) << endmsg;
 781                 return -1;
 782         }
 783
 784         while (cnt) {
 785
 786                 frames_to_read = min (frames_per_peak, cnt);
 787
 788                 if ((frames_read = read_unlocked (buf, current_frame, frames_to_read, workbuf)) != frames_to_read) {
 789                         error << string_compose(_("%1: could not write read raw data for peak computation (%2)"), _name, strerror (errno)) << endmsg;
 790                         goto out;
 791                 }
 792
 793                 xmin = buf[0];
 794                 xmax = buf[0];
 795
 796                 for (jack_nframes_t n = 1; n < frames_read; ++n) {
 797                         xmax = max (xmax, buf[n]);
 798                         xmin = min (xmin, buf[n]);
 799
 800 //                      if (current_frame < frames_read) {
 801 //                              cerr << "sample = " << buf[n] << " max = " << xmax << " min = " << xmin << " max of 2 = " << max (xmax, buf[n]) << endl;
 802 //                      }
 803                 }
 804
 805                 peakbuf[peaki].max = xmax;
 806                 peakbuf[peaki].min = xmin;
 807                 peaki++;
 808
 809                 current_frame += frames_read;
 810                 cnt -= frames_read;
 811         }
 812
 813         if (::pwrite (peakfile, peakbuf, sizeof (PeakData) * peaki, first_peak_byte) != (ssize_t) (sizeof (PeakData) * peaki)) {
 814                 error << string_compose(_("%1: could not write peak file data (%2)"), _name, strerror (errno)) << endmsg;
 815                 goto out;
 816         }
 817
 818         ret = 0;
 819
 820   out:
 821         delete [] peakbuf;
 822         if (peakfile >= 0) {
 823                 close (peakfile);
 824         }
 825         if (workbuf)
 826                 delete [] workbuf;
 827         return ret;
 828 }
 829
 830 void
 831 Source::build_peaks_from_scratch ()
 832 {
 833         LockMonitor lp (_lock, __LINE__, __FILE__);
 834
 835         next_peak_clear_should_notify = true;
 836         pending_peak_builds.push_back (new PeakBuildRecord (0, _length));
 837         queue_for_peaks (*this);
 838 }
 839
 840 bool
 841 Source::file_changed (string path)
 842 {
 843         struct stat stat_file;
 844         struct stat stat_peak;
 845
 846         int e1 = stat (path.c_str(), &stat_file);
 847         int e2 = stat (peak_path(path).c_str(), &stat_peak);
 848
 849         if (!e1 && !e2 && stat_file.st_mtime > stat_peak.st_mtime){
 850                 return true;
 851         } else {
 852                 return false;
 853         }
 854 }
 855
 856 void
 857 Source::use ()
 858 {
 859         _use_cnt++;
 860 }
 861
 862 void
 863 Source::release ()
 864 {
 865         if (_use_cnt) --_use_cnt;
 866 }
 867
 868 jack_nframes_t
 869 Source::available_peaks (double zoom_factor) const
 870 {
 871         int peakfile;
 872         off_t end;
 873
 874         if (zoom_factor < frames_per_peak) {
 875                 return length(); // peak data will come from the audio file
 876         }
 877
 878         /* peak data comes from peakfile */
 879
 880         if ((peakfile = ::open (peakpath.c_str(), O_RDONLY)) < 0) {
 881                 error << string_compose(_("Source: cannot open peakpath \"%1\" (%2)"), peakpath, strerror (errno)) << endmsg;
 882                 return 0;
 883         }
 884
 885         {
 886                 LockMonitor lm (_lock, __LINE__, __FILE__);
 887                 end = lseek (peakfile, 0, SEEK_END);
 888         }
 889
 890         close (peakfile);
 891
 892         return (end/sizeof(PeakData)) * frames_per_peak;
 893 }
 894