src/dcp.cc

   1 /*
   2     Copyright (C) 2012 Carl Hetherington <cth@carlh.net>
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17
  18 */
  19
  20 /** @file  src/dcp.cc
  21  *  @brief A class to create a DCP.
  22  */
  23
  24 #include <sstream>
  25 #include <fstream>
  26 #include <iomanip>
  27 #include <cassert>
  28 #include <iostream>
  29 #include <boost/filesystem.hpp>
  30 #include <libxml++/libxml++.h>
  31 #include <xmlsec/xmldsig.h>
  32 #include <xmlsec/app.h>
  33 #include "dcp.h"
  34 #include "asset.h"
  35 #include "sound_asset.h"
  36 #include "picture_asset.h"
  37 #include "subtitle_asset.h"
  38 #include "util.h"
  39 #include "metadata.h"
  40 #include "exceptions.h"
  41 #include "cpl_file.h"
  42 #include "pkl_file.h"
  43 #include "asset_map.h"
  44 #include "reel.h"
  45
  46 using std::string;
  47 using std::list;
  48 using std::stringstream;
  49 using std::ofstream;
  50 using std::ostream;
  51 using boost::shared_ptr;
  52 using namespace libdcp;
  53
  54 DCP::DCP (string directory)
  55         : _directory (directory)
  56         , _encrypted (false)
  57 {
  58         boost::filesystem::create_directories (directory);
  59 }
  60
  61 void
  62 DCP::write_xml () const
  63 {
  64         for (list<shared_ptr<const CPL> >::const_iterator i = _cpls.begin(); i != _cpls.end(); ++i) {
  65                 (*i)->write_xml (_encrypted, _certificates, _signer_key);
  66         }
  67
  68         string pkl_uuid = make_uuid ();
  69         string pkl_path = write_pkl (pkl_uuid);
  70
  71         write_volindex ();
  72         write_assetmap (pkl_uuid, boost::filesystem::file_size (pkl_path));
  73 }
  74
  75 std::string
  76 DCP::write_pkl (string pkl_uuid) const
  77 {
  78         assert (!_cpls.empty ());
  79
  80         boost::filesystem::path p;
  81         p /= _directory;
  82         stringstream s;
  83         s << pkl_uuid << "_pkl.xml";
  84         p /= s.str();
  85         ofstream pkl (p.string().c_str());
  86
  87         pkl << "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
  88             << "<PackingList xmlns=\"http://www.smpte-ra.org/schemas/429-8/2007/PKL\">\n"
  89             << "  <Id>urn:uuid:" << pkl_uuid << "</Id>\n"
  90                 /* XXX: this is a bit of a hack */
  91             << "  <AnnotationText>" << _cpls.front()->name() << "</AnnotationText>\n"
  92             << "  <IssueDate>" << Metadata::instance()->issue_date << "</IssueDate>\n"
  93             << "  <Issuer>" << Metadata::instance()->issuer << "</Issuer>\n"
  94             << "  <Creator>" << Metadata::instance()->creator << "</Creator>\n"
  95             << "  <AssetList>\n";
  96
  97         list<shared_ptr<const Asset> > a = assets ();
  98         for (list<shared_ptr<const Asset> >::const_iterator i = a.begin(); i != a.end(); ++i) {
  99                 (*i)->write_to_pkl (pkl);
 100         }
 101
 102         for (list<shared_ptr<const CPL> >::const_iterator i = _cpls.begin(); i != _cpls.end(); ++i) {
 103                 (*i)->write_to_pkl (pkl);
 104         }
 105
 106         pkl << "  </AssetList>\n"
 107             << "</PackingList>\n";
 108
 109         return p.string ();
 110 }
 111
 112 void
 113 DCP::write_volindex () const
 114 {
 115         boost::filesystem::path p;
 116         p /= _directory;
 117         p /= "VOLINDEX.xml";
 118         ofstream vi (p.string().c_str());
 119
 120         vi << "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
 121            << "<VolumeIndex xmlns=\"http://www.smpte-ra.org/schemas/429-9/2007/AM\">\n"
 122            << "  <Index>1</Index>\n"
 123            << "</VolumeIndex>\n";
 124 }
 125
 126 void
 127 DCP::write_assetmap (string pkl_uuid, int pkl_length) const
 128 {
 129         boost::filesystem::path p;
 130         p /= _directory;
 131         p /= "ASSETMAP.xml";
 132         ofstream am (p.string().c_str());
 133
 134         am << "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
 135            << "<AssetMap xmlns=\"http://www.smpte-ra.org/schemas/429-9/2007/AM\">\n"
 136            << "  <Id>urn:uuid:" << make_uuid() << "</Id>\n"
 137            << "  <Creator>" << Metadata::instance()->creator << "</Creator>\n"
 138            << "  <VolumeCount>1</VolumeCount>\n"
 139            << "  <IssueDate>" << Metadata::instance()->issue_date << "</IssueDate>\n"
 140            << "  <Issuer>" << Metadata::instance()->issuer << "</Issuer>\n"
 141            << "  <AssetList>\n";
 142
 143         am << "    <Asset>\n"
 144            << "      <Id>urn:uuid:" << pkl_uuid << "</Id>\n"
 145            << "      <PackingList>true</PackingList>\n"
 146            << "      <ChunkList>\n"
 147            << "        <Chunk>\n"
 148            << "          <Path>" << pkl_uuid << "_pkl.xml</Path>\n"
 149            << "          <VolumeIndex>1</VolumeIndex>\n"
 150            << "          <Offset>0</Offset>\n"
 151            << "          <Length>" << pkl_length << "</Length>\n"
 152            << "        </Chunk>\n"
 153            << "      </ChunkList>\n"
 154            << "    </Asset>\n";
 155
 156         for (list<shared_ptr<const CPL> >::const_iterator i = _cpls.begin(); i != _cpls.end(); ++i) {
 157                 (*i)->write_to_assetmap (am);
 158         }
 159
 160         list<shared_ptr<const Asset> > a = assets ();
 161         for (list<shared_ptr<const Asset> >::const_iterator i = a.begin(); i != a.end(); ++i) {
 162                 (*i)->write_to_assetmap (am);
 163         }
 164
 165         am << "  </AssetList>\n"
 166            << "</AssetMap>\n";
 167 }
 168
 169
 170 void
 171 DCP::read (bool require_mxfs)
 172 {
 173         Files files;
 174
 175         shared_ptr<AssetMap> asset_map;
 176         try {
 177                 boost::filesystem::path p = _directory;
 178                 p /= "ASSETMAP";
 179                 if (boost::filesystem::exists (p)) {
 180                         asset_map.reset (new AssetMap (p.string ()));
 181                 } else {
 182                         p = _directory;
 183                         p /= "ASSETMAP.xml";
 184                         if (boost::filesystem::exists (p)) {
 185                                 asset_map.reset (new AssetMap (p.string ()));
 186                         } else {
 187                                 throw DCPReadError ("could not find AssetMap file");
 188                         }
 189                 }
 190
 191         } catch (FileError& e) {
 192                 throw FileError ("could not load AssetMap file", files.asset_map);
 193         }
 194
 195         for (list<shared_ptr<AssetMapAsset> >::const_iterator i = asset_map->assets.begin(); i != asset_map->assets.end(); ++i) {
 196                 if ((*i)->chunks.size() != 1) {
 197                         throw XMLError ("unsupported asset chunk count");
 198                 }
 199
 200                 boost::filesystem::path t = _directory;
 201                 t /= (*i)->chunks.front()->path;
 202
 203                 if (ends_with (t.string(), ".mxf") || ends_with (t.string(), ".ttf")) {
 204                         continue;
 205                 }
 206
 207                 xmlpp::DomParser* p = new xmlpp::DomParser;
 208                 try {
 209                         p->parse_file (t.string());
 210                 } catch (std::exception& e) {
 211                         delete p;
 212                         continue;
 213                 }
 214
 215                 string const root = p->get_document()->get_root_node()->get_name ();
 216                 delete p;
 217
 218                 if (root == "CompositionPlaylist") {
 219                         files.cpls.push_back (t.string());
 220                 } else if (root == "PackingList") {
 221                         if (files.pkl.empty ()) {
 222                                 files.pkl = t.string();
 223                         } else {
 224                                 throw DCPReadError ("duplicate PKLs found");
 225                         }
 226                 }
 227         }
 228
 229         if (files.cpls.empty ()) {
 230                 throw FileError ("no CPL files found", "");
 231         }
 232
 233         if (files.pkl.empty ()) {
 234                 throw FileError ("no PKL file found", "");
 235         }
 236
 237         shared_ptr<PKLFile> pkl;
 238         try {
 239                 pkl.reset (new PKLFile (files.pkl));
 240         } catch (FileError& e) {
 241                 throw FileError ("could not load PKL file", files.pkl);
 242         }
 243
 244         /* Cross-check */
 245         /* XXX */
 246
 247         for (list<string>::iterator i = files.cpls.begin(); i != files.cpls.end(); ++i) {
 248                 _cpls.push_back (shared_ptr<CPL> (new CPL (_directory, *i, asset_map, require_mxfs)));
 249         }
 250 }
 251
 252 bool
 253 DCP::equals (DCP const & other, EqualityOptions opt, list<string>& notes) const
 254 {
 255         if (_cpls.size() != other._cpls.size()) {
 256                 notes.push_back ("CPL counts differ");
 257                 return false;
 258         }
 259
 260         list<shared_ptr<const CPL> >::const_iterator a = _cpls.begin ();
 261         list<shared_ptr<const CPL> >::const_iterator b = other._cpls.begin ();
 262
 263         while (a != _cpls.end ()) {
 264                 if (!(*a)->equals (*b->get(), opt, notes)) {
 265                         return false;
 266                 }
 267                 ++a;
 268                 ++b;
 269         }
 270
 271         return true;
 272 }
 273
 274
 275 void
 276 DCP::add_cpl (shared_ptr<CPL> cpl)
 277 {
 278         _cpls.push_back (cpl);
 279 }
 280
 281 class AssetComparator
 282 {
 283 public:
 284         bool operator() (shared_ptr<const Asset> a, shared_ptr<const Asset> b) {
 285                 return a->uuid() < b->uuid();
 286         }
 287 };
 288
 289 list<shared_ptr<const Asset> >
 290 DCP::assets () const
 291 {
 292         list<shared_ptr<const Asset> > a;
 293         for (list<shared_ptr<const CPL> >::const_iterator i = _cpls.begin(); i != _cpls.end(); ++i) {
 294                 list<shared_ptr<const Asset> > t = (*i)->assets ();
 295                 a.merge (t);
 296         }
 297
 298         a.sort (AssetComparator ());
 299         a.unique ();
 300         return a;
 301 }
 302
 303 CPL::CPL (string directory, string name, ContentKind content_kind, int length, int frames_per_second)
 304         : _directory (directory)
 305         , _name (name)
 306         , _content_kind (content_kind)
 307         , _length (length)
 308         , _fps (frames_per_second)
 309 {
 310         _uuid = make_uuid ();
 311 }
 312
 313 CPL::CPL (string directory, string file, shared_ptr<const AssetMap> asset_map, bool require_mxfs)
 314         : _directory (directory)
 315         , _content_kind (FEATURE)
 316         , _length (0)
 317         , _fps (0)
 318 {
 319         /* Read the XML */
 320         shared_ptr<CPLFile> cpl;
 321         try {
 322                 cpl.reset (new CPLFile (file));
 323         } catch (FileError& e) {
 324                 throw FileError ("could not load CPL file", file);
 325         }
 326
 327         /* Now cherry-pick the required bits into our own data structure */
 328
 329         _name = cpl->annotation_text;
 330         _content_kind = cpl->content_kind;
 331
 332         for (list<shared_ptr<CPLReel> >::iterator i = cpl->reels.begin(); i != cpl->reels.end(); ++i) {
 333
 334                 shared_ptr<Picture> p;
 335
 336                 if ((*i)->asset_list->main_picture) {
 337                         p = (*i)->asset_list->main_picture;
 338                 } else {
 339                         p = (*i)->asset_list->main_stereoscopic_picture;
 340                 }
 341
 342                 _fps = p->edit_rate.numerator;
 343                 _length += p->duration;
 344
 345                 shared_ptr<PictureAsset> picture;
 346                 shared_ptr<SoundAsset> sound;
 347                 shared_ptr<SubtitleAsset> subtitle;
 348
 349                 /* Some rather twisted logic to decide if we are 3D or not;
 350                    some DCPs give a MainStereoscopicPicture to indicate 3D, others
 351                    just have a FrameRate twice the EditRate and apparently
 352                    expect you to divine the fact that they are hence 3D.
 353                 */
 354
 355                 if (!(*i)->asset_list->main_stereoscopic_picture && p->edit_rate == p->frame_rate) {
 356
 357                         try {
 358                                 picture.reset (new MonoPictureAsset (
 359                                                        _directory,
 360                                                        asset_map->asset_from_id (p->id)->chunks.front()->path,
 361                                                        _fps,
 362                                                        (*i)->asset_list->main_picture->entry_point,
 363                                                        (*i)->asset_list->main_picture->duration
 364                                                        )
 365                                         );
 366                         } catch (MXFFileError) {
 367                                 if (require_mxfs) {
 368                                         throw;
 369                                 }
 370                         }
 371
 372                 } else {
 373
 374                         try {
 375                                 picture.reset (new StereoPictureAsset (
 376                                                        _directory,
 377                                                        asset_map->asset_from_id (p->id)->chunks.front()->path,
 378                                                        _fps,
 379                                                        p->entry_point,
 380                                                        p->duration
 381                                                        )
 382                                         );
 383                         } catch (MXFFileError) {
 384                                 if (require_mxfs) {
 385                                         throw;
 386                                 }
 387                         }
 388
 389                 }
 390
 391                 if ((*i)->asset_list->main_sound) {
 392
 393                         try {
 394                                 sound.reset (new SoundAsset (
 395                                                      _directory,
 396                                                      asset_map->asset_from_id ((*i)->asset_list->main_sound->id)->chunks.front()->path,
 397                                                      _fps,
 398                                                      (*i)->asset_list->main_sound->entry_point,
 399                                                      (*i)->asset_list->main_sound->duration
 400                                                      )
 401                                         );
 402                         } catch (MXFFileError) {
 403                                 if (require_mxfs) {
 404                                         throw;
 405                                 }
 406                         }
 407                 }
 408
 409                 if ((*i)->asset_list->main_subtitle) {
 410
 411                         subtitle.reset (new SubtitleAsset (
 412                                                 _directory,
 413                                                 asset_map->asset_from_id ((*i)->asset_list->main_subtitle->id)->chunks.front()->path
 414                                                 )
 415                                 );
 416                 }
 417
 418                 _reels.push_back (shared_ptr<Reel> (new Reel (picture, sound, subtitle)));
 419         }
 420 }
 421
 422 void
 423 CPL::add_reel (shared_ptr<const Reel> reel)
 424 {
 425         _reels.push_back (reel);
 426 }
 427
 428 void
 429 CPL::write_xml (bool encrypted, CertificateChain const & certificates, string const & signer_key) const
 430 {
 431         boost::filesystem::path p;
 432         p /= _directory;
 433         stringstream s;
 434         s << _uuid << "_cpl.xml";
 435         p /= s.str();
 436
 437         xmlpp::Document doc;
 438         xmlpp::Element* cpl = doc.create_root_node("CompositionPlaylist", "http://www.smpte-ra.org/schemas/429-7/2006/CPL");
 439
 440         if (encrypted) {
 441                 cpl->set_namespace_declaration ("http://www.w3.org/2000/09/xmldsig#", "dsig");
 442         }
 443
 444         cpl->add_child("Id")->add_child_text ("urn:uuid:" + _uuid);
 445         cpl->add_child("AnnotationText")->add_child_text (_name);
 446         cpl->add_child("IssueDate")->add_child_text (Metadata::instance()->issue_date);
 447         cpl->add_child("Creator")->add_child_text (Metadata::instance()->creator);
 448         cpl->add_child("ContentTitleText")->add_child_text (_name);
 449         cpl->add_child("ContentKind")->add_child_text (content_kind_to_string (_content_kind));
 450
 451         {
 452                 xmlpp::Element* cv = cpl->add_child ("ContentVersion");
 453                 cv->add_child("Id")->add_child_text ("urn:uri:" + _uuid + "_" + Metadata::instance()->issue_date);
 454                 cv->add_child("LabelText")->add_child_text (_uuid + "_" + Metadata::instance()->issue_date);
 455         }
 456
 457         cpl->add_child("RatingList");
 458
 459         xmlpp::Element* reel_list = cpl->add_child("ReelList");
 460         for (list<shared_ptr<const Reel> >::const_iterator i = _reels.begin(); i != _reels.end(); ++i) {
 461                 (*i)->write_to_cpl (reel_list);
 462         }
 463
 464         if (encrypted) {
 465                 xmlpp::Element* signer = cpl->add_child("Signer");
 466                 {
 467                         xmlpp::Element* data = signer->add_child("X509Data", "dsig");
 468                         {
 469                                 xmlpp::Element* serial = data->add_child("X509IssuerSerial", "dsig");
 470                                 serial->add_child("X509IssuerName", "dsig")->add_child_text (
 471                                         Certificate::name_for_xml (certificates.leaf()->issuer())
 472                                         );
 473                                 serial->add_child("X509SerialNumber", "dsig")->add_child_text (
 474                                         certificates.leaf()->serial()
 475                                         );
 476                         }
 477                         data->add_child("X509SubjectName", "dsig")->add_child_text (
 478                                 Certificate::name_for_xml (certificates.leaf()->subject())
 479                                 );
 480                 }
 481
 482                 xmlpp::Element* signature = cpl->add_child("Signature", "dsig");
 483
 484                 {
 485                         xmlpp::Element* signed_info = signature->add_child ("SignedInfo", "dsig");
 486                         signed_info->add_child("CanonicalizationMethod", "dsig")->set_attribute ("Algorithm", "http://www.w3.org/TR/2001/REC-xml-c14n-20010315");
 487                         signed_info->add_child("SignatureMethod", "dsig")->set_attribute("Algorithm", "http://www.w3.org/2001/04/xmldsig-more#rsa-sha256");
 488                         {
 489                                 xmlpp::Element* reference = signed_info->add_child("Reference", "dsig");
 490                                 reference->set_attribute ("URI", "");
 491                                 {
 492                                         xmlpp::Element* transforms = reference->add_child("Transforms", "dsig");
 493                                         transforms->add_child("Transform", "dsig")->set_attribute (
 494                                                 "Algorithm", "http://www.w3.org/2000/09/xmldsig#enveloped-signature"
 495                                                 );
 496                                 }
 497                                 reference->add_child("DigestMethod", "dsig")->set_attribute("Algorithm", "http://www.w3.org/2000/09/xmldsig#sha1");
 498                                 /* This will be filled in by the signing later */
 499                                 reference->add_child("DigestValue", "dsig");
 500                         }
 501                 }
 502
 503                 signature->add_child("SignatureValue", "dsig");
 504
 505                 xmlpp::Element* key_info = signature->add_child("KeyInfo", "dsig");
 506                 list<shared_ptr<Certificate> > c = certificates.leaf_to_root ();
 507                 for (list<shared_ptr<Certificate> >::iterator i = c.begin(); i != c.end(); ++i) {
 508                         xmlpp::Element* data = key_info->add_child("X509Data", "dsig");
 509                         {
 510                                 xmlpp::Element* serial = data->add_child("X509IssuerSerial", "dsig");
 511                                 serial->add_child("X509IssuerName", "dsig")->add_child_text(
 512                                         Certificate::name_for_xml ((*i)->issuer())
 513                                         );
 514                                 serial->add_child("X509SerialNumber", "dsig")->add_child_text((*i)->serial());
 515                         }
 516                 }
 517
 518                 xmlSecKeysMngrPtr keys_manager = xmlSecKeysMngrCreate();
 519                 if (!keys_manager) {
 520                         throw MiscError ("could not create keys manager");
 521                 }
 522                 if (xmlSecCryptoAppDefaultKeysMngrInit (keys_manager) < 0) {
 523                         throw MiscError ("could not initialise keys manager");
 524                 }
 525
 526                 xmlSecKeyPtr const key = xmlSecCryptoAppKeyLoad (signer_key.c_str(), xmlSecKeyDataFormatPem, 0, 0, 0);
 527                 if (key == 0) {
 528                         throw MiscError ("could not load signer key");
 529                 }
 530
 531                 if (xmlSecCryptoAppDefaultKeysMngrAdoptKey (keys_manager, key) < 0) {
 532                         xmlSecKeyDestroy (key);
 533                         throw MiscError ("could not use signer key");
 534                 }
 535
 536                 xmlSecDSigCtx signature_context;
 537
 538                 if (xmlSecDSigCtxInitialize (&signature_context, keys_manager) < 0) {
 539                         throw MiscError ("could not initialise XMLSEC context");
 540                 }
 541
 542                 if (xmlSecDSigCtxSign (&signature_context, signature->cobj()) < 0) {
 543                         throw MiscError ("could not sign CPL");
 544                 }
 545
 546                 xmlSecDSigCtxFinalize (&signature_context);
 547                 xmlSecKeysMngrDestroy (keys_manager);
 548         }
 549
 550         doc.write_to_file_formatted (p.string(), "UTF-8");
 551
 552         _digest = make_digest (p.string (), 0);
 553         _length = boost::filesystem::file_size (p.string ());
 554 }
 555
 556 void
 557 CPL::write_to_pkl (ostream& s) const
 558 {
 559         s << "    <Asset>\n"
 560           << "      <Id>urn:uuid:" << _uuid << "</Id>\n"
 561           << "      <Hash>" << _digest << "</Hash>\n"
 562           << "      <Size>" << _length << "</Size>\n"
 563           << "      <Type>text/xml</Type>\n"
 564           << "    </Asset>\n";
 565 }
 566
 567 list<shared_ptr<const Asset> >
 568 CPL::assets () const
 569 {
 570         list<shared_ptr<const Asset> > a;
 571         for (list<shared_ptr<const Reel> >::const_iterator i = _reels.begin(); i != _reels.end(); ++i) {
 572                 if ((*i)->main_picture ()) {
 573                         a.push_back ((*i)->main_picture ());
 574                 }
 575                 if ((*i)->main_sound ()) {
 576                         a.push_back ((*i)->main_sound ());
 577                 }
 578                 if ((*i)->main_subtitle ()) {
 579                         a.push_back ((*i)->main_subtitle ());
 580                 }
 581         }
 582
 583         return a;
 584 }
 585
 586 void
 587 CPL::write_to_assetmap (ostream& s) const
 588 {
 589         s << "    <Asset>\n"
 590           << "      <Id>urn:uuid:" << _uuid << "</Id>\n"
 591           << "      <ChunkList>\n"
 592           << "        <Chunk>\n"
 593           << "          <Path>" << _uuid << "_cpl.xml</Path>\n"
 594           << "          <VolumeIndex>1</VolumeIndex>\n"
 595           << "          <Offset>0</Offset>\n"
 596           << "          <Length>" << _length << "</Length>\n"
 597           << "        </Chunk>\n"
 598           << "      </ChunkList>\n"
 599           << "    </Asset>\n";
 600 }
 601
 602
 603
 604 bool
 605 CPL::equals (CPL const & other, EqualityOptions opt, list<string>& notes) const
 606 {
 607         if (_name != other._name) {
 608                 notes.push_back ("names differ");
 609                 return false;
 610         }
 611
 612         if (_content_kind != other._content_kind) {
 613                 notes.push_back ("content kinds differ");
 614                 return false;
 615         }
 616
 617         if (_fps != other._fps) {
 618                 notes.push_back ("frames per second differ");
 619                 return false;
 620         }
 621
 622         if (_length != other._length) {
 623                 notes.push_back ("lengths differ");
 624                 return false;
 625         }
 626
 627         if (_reels.size() != other._reels.size()) {
 628                 notes.push_back ("reel counts differ");
 629                 return false;
 630         }
 631
 632         list<shared_ptr<const Reel> >::const_iterator a = _reels.begin ();
 633         list<shared_ptr<const Reel> >::const_iterator b = other._reels.begin ();
 634
 635         while (a != _reels.end ()) {
 636                 if (!(*a)->equals (*b, opt, notes)) {
 637                         return false;
 638                 }
 639                 ++a;
 640                 ++b;
 641         }
 642
 643         return true;
 644 }