src/lib/reel_writer.cc

   1 /*
   2     Copyright (C) 2012-2016 Carl Hetherington <cth@carlh.net>
   3
   4     This file is part of DCP-o-matic.
   5
   6     DCP-o-matic is free software; you can redistribute it and/or modify
   7     it under the terms of the GNU General Public License as published by
   8     the Free Software Foundation; either version 2 of the License, or
   9     (at your option) any later version.
  10
  11     DCP-o-matic is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14     GNU General Public License for more details.
  15
  16     You should have received a copy of the GNU General Public License
  17     along with DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
  18
  19 */
  20
  21 #include "reel_writer.h"
  22 #include "film.h"
  23 #include "cross.h"
  24 #include "job.h"
  25 #include "log.h"
  26 #include "digester.h"
  27 #include "font.h"
  28 #include "compose.hpp"
  29 #include "audio_buffers.h"
  30 #include "image.h"
  31 #include <dcp/mono_picture_asset.h>
  32 #include <dcp/stereo_picture_asset.h>
  33 #include <dcp/sound_asset.h>
  34 #include <dcp/sound_asset_writer.h>
  35 #include <dcp/reel.h>
  36 #include <dcp/reel_mono_picture_asset.h>
  37 #include <dcp/reel_stereo_picture_asset.h>
  38 #include <dcp/reel_sound_asset.h>
  39 #include <dcp/reel_subtitle_asset.h>
  40 #include <dcp/dcp.h>
  41 #include <dcp/cpl.h>
  42 #include <dcp/certificate_chain.h>
  43 #include <dcp/interop_subtitle_asset.h>
  44 #include <dcp/smpte_subtitle_asset.h>
  45 #include <dcp/raw_convert.h>
  46 #include <dcp/subtitle_image.h>
  47 #include <boost/foreach.hpp>
  48
  49 #include "i18n.h"
  50
  51 #define LOG_GENERAL(...) _film->log()->log (String::compose (__VA_ARGS__), LogEntry::TYPE_GENERAL);
  52 #define LOG_GENERAL_NC(...) _film->log()->log (__VA_ARGS__, LogEntry::TYPE_GENERAL);
  53 #define LOG_WARNING_NC(...) _film->log()->log (__VA_ARGS__, LogEntry::TYPE_WARNING);
  54 #define LOG_ERROR(...) _film->log()->log (String::compose (__VA_ARGS__), LogEntry::TYPE_ERROR);
  55
  56 using std::list;
  57 using std::string;
  58 using std::cout;
  59 using boost::shared_ptr;
  60 using boost::optional;
  61 using boost::dynamic_pointer_cast;
  62 using dcp::Data;
  63 using dcp::raw_convert;
  64
  65 int const ReelWriter::_info_size = 48;
  66
  67 ReelWriter::ReelWriter (
  68         shared_ptr<const Film> film, DCPTimePeriod period, shared_ptr<Job> job, int reel_index, int reel_count, optional<string> content_summary
  69         )
  70         : _film (film)
  71         , _period (period)
  72         , _last_written_video_frame (-1)
  73         , _last_written_eyes (EYES_RIGHT)
  74         , _reel_index (reel_index)
  75         , _reel_count (reel_count)
  76         , _content_summary (content_summary)
  77 {
  78         /* Create our picture asset in a subdirectory, named according to those
  79            film's parameters which affect the video output.  We will hard-link
  80            it into the DCP later.
  81         */
  82
  83         dcp::Standard const standard = _film->interop() ? dcp::INTEROP : dcp::SMPTE;
  84
  85         if (_film->three_d ()) {
  86                 _picture_asset.reset (new dcp::StereoPictureAsset (dcp::Fraction (_film->video_frame_rate(), 1), standard));
  87         } else {
  88                 _picture_asset.reset (new   dcp::MonoPictureAsset (dcp::Fraction (_film->video_frame_rate(), 1), standard));
  89         }
  90
  91         _picture_asset->set_size (_film->frame_size ());
  92
  93         if (_film->encrypted ()) {
  94                 _picture_asset->set_key (_film->key ());
  95                 _picture_asset->set_context_id (_film->context_id ());
  96         }
  97
  98         _picture_asset->set_file (
  99                 _film->internal_video_asset_dir() / _film->internal_video_asset_filename(_period)
 100                 );
 101
 102         job->sub (_("Checking existing image data"));
 103         _first_nonexistant_frame = check_existing_picture_asset ();
 104
 105         _picture_asset_writer = _picture_asset->start_write (
 106                 _film->internal_video_asset_dir() / _film->internal_video_asset_filename(_period),
 107                 _first_nonexistant_frame > 0
 108                 );
 109
 110         if (_film->audio_channels ()) {
 111                 _sound_asset.reset (
 112                         new dcp::SoundAsset (dcp::Fraction (_film->video_frame_rate(), 1), _film->audio_frame_rate (), _film->audio_channels (), standard)
 113                         );
 114
 115                 if (_film->encrypted ()) {
 116                         _sound_asset->set_key (_film->key ());
 117                 }
 118
 119                 DCPOMATIC_ASSERT (_film->directory());
 120
 121                 /* Write the sound asset into the film directory so that we leave the creation
 122                    of the DCP directory until the last minute.
 123                 */
 124                 _sound_asset_writer = _sound_asset->start_write (
 125                         _film->directory().get() / audio_asset_filename (_sound_asset, _reel_index, _reel_count, _content_summary)
 126                         );
 127         }
 128 }
 129
 130 /** @param frame reel-relative frame */
 131 void
 132 ReelWriter::write_frame_info (Frame frame, Eyes eyes, dcp::FrameInfo info) const
 133 {
 134         FILE* file = 0;
 135         boost::filesystem::path info_file = _film->info_file (_period);
 136
 137         bool const read = boost::filesystem::exists (info_file);
 138
 139         if (read) {
 140                 file = fopen_boost (info_file, "r+b");
 141         } else {
 142                 file = fopen_boost (info_file, "wb");
 143         }
 144         if (!file) {
 145                 throw OpenFileError (info_file, errno, read);
 146         }
 147         dcpomatic_fseek (file, frame_info_position (frame, eyes), SEEK_SET);
 148         fwrite (&info.offset, sizeof (info.offset), 1, file);
 149         fwrite (&info.size, sizeof (info.size), 1, file);
 150         fwrite (info.hash.c_str(), 1, info.hash.size(), file);
 151         fclose (file);
 152 }
 153
 154 dcp::FrameInfo
 155 ReelWriter::read_frame_info (FILE* file, Frame frame, Eyes eyes) const
 156 {
 157         dcp::FrameInfo info;
 158         dcpomatic_fseek (file, frame_info_position (frame, eyes), SEEK_SET);
 159         fread (&info.offset, sizeof (info.offset), 1, file);
 160         fread (&info.size, sizeof (info.size), 1, file);
 161
 162         char hash_buffer[33];
 163         fread (hash_buffer, 1, 32, file);
 164         hash_buffer[32] = '\0';
 165         info.hash = hash_buffer;
 166
 167         return info;
 168 }
 169
 170 long
 171 ReelWriter::frame_info_position (Frame frame, Eyes eyes) const
 172 {
 173         switch (eyes) {
 174         case EYES_BOTH:
 175                 return frame * _info_size;
 176         case EYES_LEFT:
 177                 return frame * _info_size * 2;
 178         case EYES_RIGHT:
 179                 return frame * _info_size * 2 + _info_size;
 180         default:
 181                 DCPOMATIC_ASSERT (false);
 182         }
 183
 184         DCPOMATIC_ASSERT (false);
 185 }
 186
 187 Frame
 188 ReelWriter::check_existing_picture_asset ()
 189 {
 190         DCPOMATIC_ASSERT (_picture_asset->file());
 191         boost::filesystem::path asset = _picture_asset->file().get();
 192
 193         /* If there is an existing asset, break any hard links to it as we are about to change its contents
 194            (if only by changing the IDs); see #1126.
 195         */
 196
 197         if (boost::filesystem::exists(asset) && boost::filesystem::hard_link_count(asset) > 1) {
 198                 boost::filesystem::copy_file (asset, asset.string() + ".tmp");
 199                 boost::filesystem::remove (asset);
 200                 boost::filesystem::rename (asset.string() + ".tmp", asset);
 201         }
 202
 203         /* Try to open the existing asset */
 204         FILE* asset_file = fopen_boost (asset, "rb");
 205         if (!asset_file) {
 206                 LOG_GENERAL ("Could not open existing asset at %1 (errno=%2)", asset.string(), errno);
 207                 return 0;
 208         } else {
 209                 LOG_GENERAL ("Opened existing asset at %1", asset.string());
 210         }
 211
 212         /* Offset of the last dcp::FrameInfo in the info file */
 213         int const n = (boost::filesystem::file_size (_film->info_file(_period)) / _info_size) - 1;
 214         LOG_GENERAL ("The last FI is %1; info file is %2, info size %3", n, boost::filesystem::file_size (_film->info_file(_period)), _info_size);
 215
 216         FILE* info_file = fopen_boost (_film->info_file(_period), "rb");
 217         if (!info_file) {
 218                 LOG_GENERAL_NC ("Could not open film info file");
 219                 fclose (asset_file);
 220                 return 0;
 221         }
 222
 223         Frame first_nonexistant_frame;
 224         if (_film->three_d ()) {
 225                 /* Start looking at the last left frame */
 226                 first_nonexistant_frame = n / 2;
 227         } else {
 228                 first_nonexistant_frame = n;
 229         }
 230
 231         while (!existing_picture_frame_ok(asset_file, info_file, first_nonexistant_frame) && first_nonexistant_frame > 0) {
 232                 --first_nonexistant_frame;
 233         }
 234
 235         if (!_film->three_d() && first_nonexistant_frame > 0) {
 236                 /* If we are doing 3D we might have found a good L frame with no R, so only
 237                    do this if we're in 2D and we've just found a good B(oth) frame.
 238                 */
 239                 ++first_nonexistant_frame;
 240         }
 241
 242         LOG_GENERAL ("Proceeding with first nonexistant frame %1", first_nonexistant_frame);
 243
 244         fclose (asset_file);
 245         fclose (info_file);
 246
 247         return first_nonexistant_frame;
 248 }
 249
 250 void
 251 ReelWriter::write (optional<Data> encoded, Frame frame, Eyes eyes)
 252 {
 253         dcp::FrameInfo fin = _picture_asset_writer->write (encoded->data().get (), encoded->size());
 254         write_frame_info (frame, eyes, fin);
 255         _last_written[eyes] = encoded;
 256         _last_written_video_frame = frame;
 257         _last_written_eyes = eyes;
 258 }
 259
 260 void
 261 ReelWriter::fake_write (Frame frame, Eyes eyes, int size)
 262 {
 263         _picture_asset_writer->fake_write (size);
 264         _last_written_video_frame = frame;
 265         _last_written_eyes = eyes;
 266 }
 267
 268 void
 269 ReelWriter::repeat_write (Frame frame, Eyes eyes)
 270 {
 271         dcp::FrameInfo fin = _picture_asset_writer->write (
 272                 _last_written[eyes]->data().get(),
 273                 _last_written[eyes]->size()
 274                 );
 275         write_frame_info (frame, eyes, fin);
 276         _last_written_video_frame = frame;
 277         _last_written_eyes = eyes;
 278 }
 279
 280 void
 281 ReelWriter::finish ()
 282 {
 283         if (!_picture_asset_writer->finalize ()) {
 284                 /* Nothing was written to the picture asset */
 285                 LOG_GENERAL ("Nothing was written to reel %1 of %2", _reel_index, _reel_count);
 286                 _picture_asset.reset ();
 287         }
 288
 289         if (_sound_asset_writer && !_sound_asset_writer->finalize ()) {
 290                 /* Nothing was written to the sound asset */
 291                 _sound_asset.reset ();
 292         }
 293
 294         /* Hard-link any video asset file into the DCP */
 295         if (_picture_asset) {
 296                 DCPOMATIC_ASSERT (_picture_asset->file());
 297                 boost::filesystem::path video_from = _picture_asset->file().get();
 298                 boost::filesystem::path video_to;
 299                 video_to /= _film->dir (_film->dcp_name());
 300                 video_to /= video_asset_filename (_picture_asset, _reel_index, _reel_count, _content_summary);
 301
 302                 boost::system::error_code ec;
 303                 boost::filesystem::create_hard_link (video_from, video_to, ec);
 304                 if (ec) {
 305                         LOG_WARNING_NC ("Hard-link failed; copying instead");
 306                         boost::filesystem::copy_file (video_from, video_to, ec);
 307                         if (ec) {
 308                                 LOG_ERROR ("Failed to copy video file from %1 to %2 (%3)", video_from.string(), video_to.string(), ec.message ());
 309                                 throw FileError (ec.message(), video_from);
 310                         }
 311                 }
 312
 313                 _picture_asset->set_file (video_to);
 314         }
 315
 316         /* Move the audio asset into the DCP */
 317         if (_sound_asset) {
 318                 boost::filesystem::path audio_to;
 319                 audio_to /= _film->dir (_film->dcp_name ());
 320                 string const aaf = audio_asset_filename (_sound_asset, _reel_index, _reel_count, _content_summary);
 321                 audio_to /= aaf;
 322
 323                 boost::system::error_code ec;
 324                 boost::filesystem::rename (_film->file (aaf), audio_to, ec);
 325                 if (ec) {
 326                         throw FileError (
 327                                 String::compose (_("could not move audio asset into the DCP (%1)"), ec.value ()), aaf
 328                                 );
 329                 }
 330
 331                 _sound_asset->set_file (audio_to);
 332         }
 333 }
 334
 335 shared_ptr<dcp::Reel>
 336 ReelWriter::create_reel (list<ReferencedReelAsset> const & refs, list<shared_ptr<Font> > const & fonts)
 337 {
 338         shared_ptr<dcp::Reel> reel (new dcp::Reel ());
 339
 340         shared_ptr<dcp::ReelPictureAsset> reel_picture_asset;
 341
 342         if (_picture_asset) {
 343                 /* We have made a picture asset of our own.  Put it into the reel */
 344                 shared_ptr<dcp::MonoPictureAsset> mono = dynamic_pointer_cast<dcp::MonoPictureAsset> (_picture_asset);
 345                 if (mono) {
 346                         reel_picture_asset.reset (new dcp::ReelMonoPictureAsset (mono, 0));
 347                 }
 348
 349                 shared_ptr<dcp::StereoPictureAsset> stereo = dynamic_pointer_cast<dcp::StereoPictureAsset> (_picture_asset);
 350                 if (stereo) {
 351                         reel_picture_asset.reset (new dcp::ReelStereoPictureAsset (stereo, 0));
 352                 }
 353         } else {
 354                 LOG_GENERAL ("no picture asset of our own; look through %1", refs.size());
 355                 /* We don't have a picture asset of our own; hopefully we have one to reference */
 356                 BOOST_FOREACH (ReferencedReelAsset j, refs) {
 357                         shared_ptr<dcp::ReelPictureAsset> k = dynamic_pointer_cast<dcp::ReelPictureAsset> (j.asset);
 358                         if (k) {
 359                                 LOG_GENERAL ("candidate picture asset period is %1-%2", j.period.from.get(), j.period.to.get());
 360                         }
 361                         if (k && j.period == _period) {
 362                                 reel_picture_asset = k;
 363                         }
 364                 }
 365         }
 366
 367         LOG_GENERAL ("create_reel for %1-%2; %3 of %4", _period.from.get(), _period.to.get(), _reel_index, _reel_count);
 368
 369         Frame const period_duration = _period.duration().frames_round(_film->video_frame_rate());
 370
 371         DCPOMATIC_ASSERT (reel_picture_asset);
 372         if (reel_picture_asset->duration() != period_duration) {
 373                 throw ProgrammingError (
 374                         __FILE__, __LINE__,
 375                         String::compose ("%1 vs %2", reel_picture_asset->duration(), period_duration)
 376                         );
 377         }
 378         reel->add (reel_picture_asset);
 379
 380         /* If we have a hash for this asset in the CPL, assume that it is correct */
 381         if (reel_picture_asset->hash()) {
 382                 reel_picture_asset->asset_ref()->set_hash (reel_picture_asset->hash().get());
 383         }
 384
 385         shared_ptr<dcp::ReelSoundAsset> reel_sound_asset;
 386
 387         if (_sound_asset) {
 388                 /* We have made a sound asset of our own.  Put it into the reel */
 389                 reel_sound_asset.reset (new dcp::ReelSoundAsset (_sound_asset, 0));
 390         } else {
 391                 /* We don't have a sound asset of our own; hopefully we have one to reference */
 392                 BOOST_FOREACH (ReferencedReelAsset j, refs) {
 393                         shared_ptr<dcp::ReelSoundAsset> k = dynamic_pointer_cast<dcp::ReelSoundAsset> (j.asset);
 394                         if (k && j.period == _period) {
 395                                 reel_sound_asset = k;
 396                                 /* If we have a hash for this asset in the CPL, assume that it is correct */
 397                                 if (k->hash()) {
 398                                         k->asset_ref()->set_hash (k->hash().get());
 399                                 }
 400                         }
 401                 }
 402         }
 403
 404         DCPOMATIC_ASSERT (reel_sound_asset);
 405         if (reel_sound_asset->duration() != period_duration) {
 406                 LOG_ERROR (
 407                         "Reel sound asset has length %1 but reel period is %2",
 408                         reel_sound_asset->duration(),
 409                         period_duration
 410                         );
 411                 if (reel_sound_asset->duration() != period_duration) {
 412                         throw ProgrammingError (
 413                                 __FILE__, __LINE__,
 414                                 String::compose ("%1 vs %2", reel_sound_asset->duration(), period_duration)
 415                                 );
 416                 }
 417
 418         }
 419         reel->add (reel_sound_asset);
 420
 421         shared_ptr<dcp::ReelSubtitleAsset> reel_subtitle_asset;
 422
 423         if (_subtitle_asset) {
 424
 425                 boost::filesystem::path liberation_normal;
 426                 try {
 427                         liberation_normal = shared_path() / "LiberationSans-Regular.ttf";
 428                         if (!boost::filesystem::exists (liberation_normal)) {
 429                                 /* Hack for unit tests */
 430                                 liberation_normal = shared_path() / "fonts" / "LiberationSans-Regular.ttf";
 431                         }
 432                 } catch (boost::filesystem::filesystem_error& e) {
 433
 434                 }
 435
 436                 if (!boost::filesystem::exists(liberation_normal)) {
 437                         liberation_normal = "/usr/share/fonts/truetype/liberation/LiberationSans-Regular.ttf";
 438                 }
 439
 440                 /* Add all the fonts to the subtitle content */
 441                 BOOST_FOREACH (shared_ptr<Font> j, fonts) {
 442                         _subtitle_asset->add_font (j->id(), j->file(FontFiles::NORMAL).get_value_or(liberation_normal));
 443                 }
 444
 445                 if (dynamic_pointer_cast<dcp::InteropSubtitleAsset> (_subtitle_asset)) {
 446                         boost::filesystem::path directory = _film->dir (_film->dcp_name ()) / _subtitle_asset->id ();
 447                         boost::filesystem::create_directories (directory);
 448                         _subtitle_asset->write (directory / ("sub_" + _subtitle_asset->id() + ".xml"));
 449                 } else {
 450
 451                         /* All our assets should be the same length; use the picture asset length here
 452                            as a reference to set the subtitle one.  We'll use the duration rather than
 453                            the intrinsic duration; we don't care if the picture asset has been trimmed, we're
 454                            just interested in its presentation length.
 455                         */
 456                         dynamic_pointer_cast<dcp::SMPTESubtitleAsset>(_subtitle_asset)->set_intrinsic_duration (
 457                                 reel_picture_asset->duration ()
 458                                 );
 459
 460                         _subtitle_asset->write (
 461                                 _film->dir (_film->dcp_name ()) / ("sub_" + _subtitle_asset->id() + ".mxf")
 462                                 );
 463                 }
 464
 465                 reel_subtitle_asset.reset (
 466                         new dcp::ReelSubtitleAsset (
 467                                 _subtitle_asset,
 468                                 dcp::Fraction (_film->video_frame_rate(), 1),
 469                                 reel_picture_asset->duration(),
 470                                 0
 471                                 )
 472                         );
 473         } else {
 474                 /* We don't have a subtitle asset of our own; hopefully we have one to reference */
 475                 BOOST_FOREACH (ReferencedReelAsset j, refs) {
 476                         shared_ptr<dcp::ReelSubtitleAsset> k = dynamic_pointer_cast<dcp::ReelSubtitleAsset> (j.asset);
 477                         if (k && j.period == _period) {
 478                                 reel_subtitle_asset = k;
 479                                 /* If we have a hash for this asset in the CPL, assume that it is correct */
 480                                 if (k->hash()) {
 481                                         k->asset_ref()->set_hash (k->hash().get());
 482                                 }
 483                         }
 484                 }
 485         }
 486
 487         if (reel_subtitle_asset) {
 488                 if (reel_subtitle_asset->duration() != period_duration) {
 489                         throw ProgrammingError (
 490                                 __FILE__, __LINE__,
 491                                 String::compose ("%1 vs %2", reel_subtitle_asset->duration(), period_duration)
 492                                 );
 493                 }
 494                 reel->add (reel_subtitle_asset);
 495         }
 496
 497         return reel;
 498 }
 499
 500 void
 501 ReelWriter::calculate_digests (boost::function<void (float)> set_progress)
 502 {
 503         if (_picture_asset) {
 504                 _picture_asset->hash (set_progress);
 505         }
 506
 507         if (_sound_asset) {
 508                 _sound_asset->hash (set_progress);
 509         }
 510 }
 511
 512 Frame
 513 ReelWriter::start () const
 514 {
 515         return _period.from.frames_floor (_film->video_frame_rate());
 516 }
 517
 518
 519 void
 520 ReelWriter::write (shared_ptr<const AudioBuffers> audio)
 521 {
 522         if (!_sound_asset_writer) {
 523                 return;
 524         }
 525
 526         DCPOMATIC_ASSERT (audio);
 527         _sound_asset_writer->write (audio->data(), audio->frames());
 528 }
 529
 530 void
 531 ReelWriter::write (PlayerText subs, DCPTimePeriod period)
 532 {
 533         if (!_subtitle_asset) {
 534                 string lang = _film->subtitle_language ();
 535                 if (lang.empty ()) {
 536                         lang = "Unknown";
 537                 }
 538                 if (_film->interop ()) {
 539                         shared_ptr<dcp::InteropSubtitleAsset> s (new dcp::InteropSubtitleAsset ());
 540                         s->set_movie_title (_film->name ());
 541                         s->set_language (lang);
 542                         s->set_reel_number (raw_convert<string> (_reel_index + 1));
 543                         _subtitle_asset = s;
 544                 } else {
 545                         shared_ptr<dcp::SMPTESubtitleAsset> s (new dcp::SMPTESubtitleAsset ());
 546                         s->set_content_title_text (_film->name ());
 547                         s->set_language (lang);
 548                         s->set_edit_rate (dcp::Fraction (_film->video_frame_rate (), 1));
 549                         s->set_reel_number (_reel_index + 1);
 550                         s->set_time_code_rate (_film->video_frame_rate ());
 551                         s->set_start_time (dcp::Time ());
 552                         if (_film->encrypted ()) {
 553                                 s->set_key (_film->key ());
 554                         }
 555                         _subtitle_asset = s;
 556                 }
 557         }
 558
 559         BOOST_FOREACH (PlainText i, subs.text) {
 560                 /* XXX: couldn't / shouldn't we use period here rather than getting time from the subtitle? */
 561                 i.set_in  (i.in()  - dcp::Time (_period.from.seconds(), i.in().tcr));
 562                 i.set_out (i.out() - dcp::Time (_period.from.seconds(), i.out().tcr));
 563                 _subtitle_asset->add (shared_ptr<dcp::Subtitle>(new dcp::SubtitleString(i)));
 564         }
 565
 566         BOOST_FOREACH (BitmapText i, subs.image) {
 567                 _subtitle_asset->add (
 568                         shared_ptr<dcp::Subtitle>(
 569                                 new dcp::SubtitleImage(
 570                                         i.image->as_png(),
 571                                         dcp::Time(period.from.seconds(), _film->video_frame_rate()),
 572                                         dcp::Time(period.to.seconds(), _film->video_frame_rate()),
 573                                         i.rectangle.x, dcp::HALIGN_LEFT, i.rectangle.y, dcp::VALIGN_TOP,
 574                                         dcp::Time(), dcp::Time()
 575                                         )
 576                                 )
 577                         );
 578         }
 579 }
 580
 581 bool
 582 ReelWriter::existing_picture_frame_ok (FILE* asset_file, FILE* info_file, Frame frame) const
 583 {
 584         LOG_GENERAL ("Checking existing picture frame %1", frame);
 585
 586         /* Read the data from the info file; for 3D we just check the left
 587            frames until we find a good one.
 588         */
 589         dcp::FrameInfo const info = read_frame_info (info_file, frame, _film->three_d () ? EYES_LEFT : EYES_BOTH);
 590
 591         bool ok = true;
 592
 593         /* Read the data from the asset and hash it */
 594         dcpomatic_fseek (asset_file, info.offset, SEEK_SET);
 595         Data data (info.size);
 596         size_t const read = fread (data.data().get(), 1, data.size(), asset_file);
 597         LOG_GENERAL ("Read %1 bytes of asset data; wanted %2", read, info.size);
 598         if (read != static_cast<size_t> (data.size ())) {
 599                 LOG_GENERAL ("Existing frame %1 is incomplete", frame);
 600                 ok = false;
 601         } else {
 602                 Digester digester;
 603                 digester.add (data.data().get(), data.size());
 604                 LOG_GENERAL ("Hash %1 vs %2", digester.get(), info.hash);
 605                 if (digester.get() != info.hash) {
 606                         LOG_GENERAL ("Existing frame %1 failed hash check", frame);
 607                         ok = false;
 608                 }
 609         }
 610
 611         return ok;
 612 }