Use new Context to reduce some boilerplate.
authorCarl Hetherington <cth@carlh.net>
Sun, 7 Jan 2024 23:44:50 +0000 (00:44 +0100)
committerCarl Hetherington <cth@carlh.net>
Sun, 14 Apr 2024 15:21:15 +0000 (17:21 +0200)
src/verify.cc

index a14f5446aa8297674847f7e3804e80af1ab9f7e1..9dee373aff10345cff899767776da9a2bac6877e 100644 (file)
@@ -293,9 +293,80 @@ parse (XercesDOMParser& parser, string xml)
 }
 
 
+class Context
+{
+public:
+       Context(
+               std::vector<VerificationNote>& notes_,
+               boost::filesystem::path xsd_dtd_directory_,
+               function<void (string, optional<boost::filesystem::path>)> stage_,
+               function<void (float)> progress_,
+               VerificationOptions options_
+              )
+               : notes(notes_)
+               , xsd_dtd_directory(xsd_dtd_directory_)
+               , stage(stage_)
+               , progress(progress_)
+               , options(options_)
+       {
+
+       }
+
+       Context(Context const&) = delete;
+       Context& operator=(Context const&) = delete;
+
+       template<typename... Args>
+       void ok(dcp::VerificationNote::Code code, Args... args)
+       {
+               add_note({dcp::VerificationNote::Type::OK, code, std::forward<Args>(args)...});
+       }
+
+       template<typename... Args>
+       void warning(dcp::VerificationNote::Code code, Args... args)
+       {
+               add_note({dcp::VerificationNote::Type::WARNING, code, std::forward<Args>(args)...});
+       }
+
+       template<typename... Args>
+       void bv21_error(dcp::VerificationNote::Code code, Args... args)
+       {
+               add_note({dcp::VerificationNote::Type::BV21_ERROR, code, std::forward<Args>(args)...});
+       }
+
+       template<typename... Args>
+       void error(dcp::VerificationNote::Code code, Args... args)
+       {
+               add_note({dcp::VerificationNote::Type::ERROR, code, std::forward<Args>(args)...});
+       }
+
+       void add_note(dcp::VerificationNote note)
+       {
+               notes.push_back(std::move(note));
+       }
+
+       void add_note_if_not_existing(dcp::VerificationNote note)
+       {
+               if (find(notes.begin(), notes.end(), note) == notes.end()) {
+                       add_note(note);
+               }
+       }
+
+       std::vector<VerificationNote>& notes;
+       std::shared_ptr<const DCP> dcp;
+       std::shared_ptr<const CPL> cpl;
+       boost::filesystem::path xsd_dtd_directory;
+       function<void (string, optional<boost::filesystem::path>)> stage;
+       function<void (float)> progress;
+       VerificationOptions options;
+
+       boost::optional<string> subtitle_language;
+       boost::optional<int> audio_channels;
+};
+
+
 template <class T>
 void
-validate_xml (T xml, boost::filesystem::path xsd_dtd_directory, vector<VerificationNote>& notes)
+validate_xml(Context& context, T xml)
 {
        try {
                XMLPlatformUtils::Initialize ();
@@ -348,7 +419,7 @@ validate_xml (T xml, boost::filesystem::path xsd_dtd_directory, vector<Verificat
                parser.setValidationSchemaFullChecking(true);
                parser.setErrorHandler(&error_handler);
 
-               LocalFileResolver resolver (xsd_dtd_directory);
+               LocalFileResolver resolver(context.xsd_dtd_directory);
                parser.setEntityResolver(&resolver);
 
                try {
@@ -366,13 +437,12 @@ validate_xml (T xml, boost::filesystem::path xsd_dtd_directory, vector<Verificat
        XMLPlatformUtils::Terminate ();
 
        for (auto i: error_handler.errors()) {
-               notes.push_back ({
-                       VerificationNote::Type::ERROR,
+               context.error(
                        VerificationNote::Code::INVALID_XML,
                        i.message(),
                        boost::trim_copy(i.public_id() + " " + i.system_id()),
                        i.line()
-               });
+               );
        }
 }
 
@@ -386,9 +456,8 @@ enum class VerifyAssetResult {
 
 static VerifyAssetResult
 verify_asset(
-       shared_ptr<const DCP> dcp,
+       Context& context,
        shared_ptr<const ReelFileAsset> reel_file_asset,
-       function<void (float)> progress,
        string* reference_hash,
        string* calculated_hash
        )
@@ -402,11 +471,11 @@ verify_asset(
         * call to hash().
         */
        reel_file_asset->asset_ref()->unset_hash();
-       *calculated_hash = reel_file_asset->asset_ref()->hash([progress](int64_t done, int64_t total) {
-               progress(float(done) / total);
+       *calculated_hash = reel_file_asset->asset_ref()->hash([&context](int64_t done, int64_t total) {
+               context.progress(float(done) / total);
        });
 
-       auto pkls = dcp->pkls();
+       auto pkls = context.dcp->pkls();
        /* We've read this DCP in so it must have at least one PKL */
        DCP_ASSERT (!pkls.empty());
 
@@ -436,28 +505,31 @@ verify_asset(
 }
 
 
-void
-verify_language_tag (string tag, vector<VerificationNote>& notes)
+static void
+verify_language_tag(Context& context, string tag)
 {
        try {
                LanguageTag test (tag);
        } catch (LanguageTagError &) {
-               notes.push_back ({VerificationNote::Type::BV21_ERROR, VerificationNote::Code::INVALID_LANGUAGE, tag});
+               context.bv21_error(VerificationNote::Code::INVALID_LANGUAGE, tag);
        }
 }
 
 
 static void
-verify_picture_asset(shared_ptr<const ReelFileAsset> reel_file_asset, boost::filesystem::path file, int64_t start_frame, vector<VerificationNote>& notes, function<void (float)> progress)
+verify_picture_asset(
+       Context& context,
+       shared_ptr<const ReelFileAsset> reel_file_asset,
+       boost::filesystem::path file,
+       int64_t start_frame
+       )
 {
        auto asset = dynamic_pointer_cast<PictureAsset>(reel_file_asset->asset_ref().asset());
        auto const duration = asset->intrinsic_duration ();
 
-       auto check_and_add = [&notes](vector<VerificationNote> const& j2k_notes) {
+       auto check_and_add = [&context](vector<VerificationNote> const& j2k_notes) {
                for (auto i: j2k_notes) {
-                       if (find(notes.begin(), notes.end(), i) == notes.end()) {
-                               notes.push_back (i);
-                       }
+                       context.add_note_if_not_existing(i);
                }
        };
 
@@ -466,19 +538,21 @@ verify_picture_asset(shared_ptr<const ReelFileAsset> reel_file_asset, boost::fil
 
        bool any_bad_frames_seen = false;
 
-       auto check_frame_size = [max_frame, risky_frame, file, start_frame, &any_bad_frames_seen](int index, int size, int frame_rate, vector<VerificationNote>& notes) {
+       auto check_frame_size = [max_frame, risky_frame, file, start_frame, &any_bad_frames_seen](Context& context, int index, int size, int frame_rate) {
                if (size > max_frame) {
-                       notes.push_back(
+                       context.add_note(
                                VerificationNote(
                                        VerificationNote::Type::ERROR, VerificationNote::Code::INVALID_PICTURE_FRAME_SIZE_IN_BYTES, file
                                        ).set_frame(start_frame + index).set_frame_rate(frame_rate)
                        );
+                       any_bad_frames_seen = true;
                } else if (size > risky_frame) {
-                       notes.push_back(
+                       context.add_note(
                                VerificationNote(
                                        VerificationNote::Type::WARNING, VerificationNote::Code::NEARLY_INVALID_PICTURE_FRAME_SIZE_IN_BYTES, file
                                        ).set_frame(start_frame + index).set_frame_rate(frame_rate)
                        );
+                       any_bad_frames_seen = true;
                }
        };
 
@@ -486,59 +560,51 @@ verify_picture_asset(shared_ptr<const ReelFileAsset> reel_file_asset, boost::fil
                auto reader = mono_asset->start_read ();
                for (int64_t i = 0; i < duration; ++i) {
                        auto frame = reader->get_frame (i);
-                       check_frame_size(i, frame->size(), mono_asset->frame_rate().numerator, notes);
+                       check_frame_size(context, i, frame->size(), mono_asset->frame_rate().numerator);
                        if (!mono_asset->encrypted() || mono_asset->key()) {
                                vector<VerificationNote> j2k_notes;
                                verify_j2k(frame, start_frame, i, mono_asset->frame_rate().numerator, j2k_notes);
                                check_and_add (j2k_notes);
                        }
-                       progress (float(i) / duration);
+                       context.progress(float(i) / duration);
                }
        } else if (auto stereo_asset = dynamic_pointer_cast<StereoPictureAsset>(asset)) {
                auto reader = stereo_asset->start_read ();
                for (int64_t i = 0; i < duration; ++i) {
                        auto frame = reader->get_frame (i);
-                       check_frame_size(i, frame->left()->size(), stereo_asset->frame_rate().numerator, notes);
-                       check_frame_size(i, frame->right()->size(), stereo_asset->frame_rate().numerator, notes);
+                       check_frame_size(context, i, frame->left()->size(), stereo_asset->frame_rate().numerator);
+                       check_frame_size(context, i, frame->right()->size(), stereo_asset->frame_rate().numerator);
                        if (!stereo_asset->encrypted() || stereo_asset->key()) {
                                vector<VerificationNote> j2k_notes;
                                verify_j2k(frame->left(), start_frame, i, stereo_asset->frame_rate().numerator, j2k_notes);
                                verify_j2k(frame->right(), start_frame, i, stereo_asset->frame_rate().numerator, j2k_notes);
                                check_and_add (j2k_notes);
                        }
-                       progress (float(i) / duration);
+                       context.progress(float(i) / duration);
                }
 
        }
 
        if (!any_bad_frames_seen) {
-               notes.push_back({VerificationNote::Type::OK, VerificationNote::Code::VALID_PICTURE_FRAME_SIZES_IN_BYTES, file});
+               context.ok(VerificationNote::Code::VALID_PICTURE_FRAME_SIZES_IN_BYTES, file);
        }
 }
 
 
 static void
-verify_main_picture_asset (
-       shared_ptr<const DCP> dcp,
-       shared_ptr<const ReelPictureAsset> reel_asset,
-       int64_t start_frame,
-       function<void (string, optional<boost::filesystem::path>)> stage,
-       function<void (float)> progress,
-       VerificationOptions options,
-       vector<VerificationNote>& notes
-       )
+verify_main_picture_asset(Context& context, shared_ptr<const ReelPictureAsset> reel_asset, int64_t start_frame)
 {
        auto asset = reel_asset->asset();
        auto const file = *asset->file();
 
-       if (options.check_asset_hashes && (!options.maximum_asset_size_for_hash_check || filesystem::file_size(file) < *options.maximum_asset_size_for_hash_check)) {
-               stage ("Checking picture asset hash", file);
+       if (context.options.check_asset_hashes && (!context.options.maximum_asset_size_for_hash_check || filesystem::file_size(file) < *context.options.maximum_asset_size_for_hash_check)) {
+               context.stage("Checking picture asset hash", file);
                string reference_hash;
                string calculated_hash;
-               auto const r = verify_asset(dcp, reel_asset, progress, &reference_hash, &calculated_hash);
+               auto const r = verify_asset(context, reel_asset, &reference_hash, &calculated_hash);
                switch (r) {
                        case VerifyAssetResult::BAD:
-                               notes.push_back(
+                               context.notes.push_back(
                                        dcp::VerificationNote(
                                                VerificationNote::Type::ERROR,
                                                VerificationNote::Code::INCORRECT_PICTURE_HASH,
@@ -547,20 +613,16 @@ verify_main_picture_asset (
                                        );
                                break;
                        case VerifyAssetResult::CPL_PKL_DIFFER:
-                               notes.push_back ({
-                                       VerificationNote::Type::ERROR, VerificationNote::Code::MISMATCHED_PICTURE_HASHES, file
-                               });
+                               context.error(VerificationNote::Code::MISMATCHED_PICTURE_HASHES, file);
                                break;
                        default:
-                               notes.push_back ({
-                                       VerificationNote::Type::OK, VerificationNote::Code::CORRECT_PICTURE_HASH, file
-                               });
+                               context.ok(VerificationNote::Code::CORRECT_PICTURE_HASH, file);
                                break;
                }
        }
 
-       stage ("Checking picture frame sizes", asset->file());
-       verify_picture_asset(reel_asset, file, start_frame, notes, progress);
+       context.stage("Checking picture frame sizes", asset->file());
+       verify_picture_asset(context, reel_asset, file, start_frame);
 
        /* Only flat/scope allowed by Bv2.1 */
        if (
@@ -568,12 +630,7 @@ verify_main_picture_asset (
                asset->size() != Size(1998, 1080) &&
                asset->size() != Size(4096, 1716) &&
                asset->size() != Size(3996, 2160)) {
-               notes.push_back({
-                       VerificationNote::Type::BV21_ERROR,
-                       VerificationNote::Code::INVALID_PICTURE_SIZE_IN_PIXELS,
-                       String::compose("%1x%2", asset->size().width, asset->size().height),
-                       file
-               });
+               context.bv21_error(VerificationNote::Code::INVALID_PICTURE_SIZE_IN_PIXELS, String::compose("%1x%2", asset->size().width, asset->size().height), file);
        }
 
        /* Only 24, 25, 48fps allowed for 2K */
@@ -581,69 +638,50 @@ verify_main_picture_asset (
                (asset->size() == Size(2048, 858) || asset->size() == Size(1998, 1080)) &&
                (asset->edit_rate() != Fraction(24, 1) && asset->edit_rate() != Fraction(25, 1) && asset->edit_rate() != Fraction(48, 1))
           ) {
-               notes.push_back({
-                       VerificationNote::Type::BV21_ERROR,
+               context.bv21_error(
                        VerificationNote::Code::INVALID_PICTURE_FRAME_RATE_FOR_2K,
                        String::compose("%1/%2", asset->edit_rate().numerator, asset->edit_rate().denominator),
                        file
-               });
+               );
        }
 
        if (asset->size() == Size(4096, 1716) || asset->size() == Size(3996, 2160)) {
                /* Only 24fps allowed for 4K */
                if (asset->edit_rate() != Fraction(24, 1)) {
-                       notes.push_back({
-                               VerificationNote::Type::BV21_ERROR,
+                       context.bv21_error(
                                VerificationNote::Code::INVALID_PICTURE_FRAME_RATE_FOR_4K,
                                String::compose("%1/%2", asset->edit_rate().numerator, asset->edit_rate().denominator),
                                file
-                       });
+                       );
                }
 
                /* Only 2D allowed for 4K */
                if (dynamic_pointer_cast<const StereoPictureAsset>(asset)) {
-                       notes.push_back({
-                               VerificationNote::Type::BV21_ERROR,
+                       context.bv21_error(
                                VerificationNote::Code::INVALID_PICTURE_ASSET_RESOLUTION_FOR_3D,
                                String::compose("%1/%2", asset->edit_rate().numerator, asset->edit_rate().denominator),
                                file
-                       });
+                       );
 
                }
        }
-
 }
 
 
-struct State
-{
-       boost::optional<string> subtitle_language;
-       boost::optional<int> audio_channels;
-};
-
-
 static void
-verify_main_sound_asset (
-       shared_ptr<const DCP> dcp,
-       shared_ptr<const ReelSoundAsset> reel_asset,
-       function<void (string, optional<boost::filesystem::path>)> stage,
-       function<void (float)> progress,
-       VerificationOptions options,
-       vector<VerificationNote>& notes,
-       State& state
-       )
+verify_main_sound_asset(Context& context, shared_ptr<const ReelSoundAsset> reel_asset)
 {
        auto asset = reel_asset->asset();
        auto const file = *asset->file();
 
-       if (options.check_asset_hashes && (!options.maximum_asset_size_for_hash_check || filesystem::file_size(file) < *options.maximum_asset_size_for_hash_check)) {
-               stage("Checking sound asset hash", file);
+       if (context.options.check_asset_hashes && (!context.options.maximum_asset_size_for_hash_check || filesystem::file_size(file) < *context.options.maximum_asset_size_for_hash_check)) {
+               context.stage("Checking sound asset hash", file);
                string reference_hash;
                string calculated_hash;
-               auto const r = verify_asset(dcp, reel_asset, progress, &reference_hash, &calculated_hash);
+               auto const r = verify_asset(context, reel_asset, &reference_hash, &calculated_hash);
                switch (r) {
                        case VerifyAssetResult::BAD:
-                               notes.push_back(
+                               context.notes.push_back(
                                        dcp::VerificationNote(
                                                VerificationNote::Type::ERROR,
                                                VerificationNote::Code::INCORRECT_SOUND_HASH,
@@ -652,58 +690,58 @@ verify_main_sound_asset (
                                        );
                                break;
                        case VerifyAssetResult::CPL_PKL_DIFFER:
-                               notes.push_back({VerificationNote::Type::ERROR, VerificationNote::Code::MISMATCHED_SOUND_HASHES, file});
+                               context.error(VerificationNote::Code::MISMATCHED_SOUND_HASHES, file);
                                break;
                        default:
                                break;
                }
        }
 
-       if (!state.audio_channels) {
-               state.audio_channels = asset->channels();
-       } else if (*state.audio_channels != asset->channels()) {
-               notes.push_back({ VerificationNote::Type::ERROR, VerificationNote::Code::MISMATCHED_SOUND_CHANNEL_COUNTS, file });
+       if (!context.audio_channels) {
+               context.audio_channels = asset->channels();
+       } else if (*context.audio_channels != asset->channels()) {
+               context.error(VerificationNote::Code::MISMATCHED_SOUND_CHANNEL_COUNTS, file);
        }
 
-       stage ("Checking sound asset metadata", file);
+       context.stage("Checking sound asset metadata", file);
 
        if (auto lang = asset->language()) {
-               verify_language_tag (*lang, notes);
+               verify_language_tag(context, *lang);
        }
        if (asset->sampling_rate() != 48000) {
-               notes.push_back({VerificationNote::Type::BV21_ERROR, VerificationNote::Code::INVALID_SOUND_FRAME_RATE, raw_convert<string>(asset->sampling_rate()), file});
+               context.bv21_error(VerificationNote::Code::INVALID_SOUND_FRAME_RATE, raw_convert<string>(asset->sampling_rate()), file);
        }
 }
 
 
 static void
-verify_main_subtitle_reel (shared_ptr<const ReelSubtitleAsset> reel_asset, vector<VerificationNote>& notes)
+verify_main_subtitle_reel(Context& context, shared_ptr<const ReelSubtitleAsset> reel_asset)
 {
        /* XXX: is Language compulsory? */
        if (reel_asset->language()) {
-               verify_language_tag (*reel_asset->language(), notes);
+               verify_language_tag(context, *reel_asset->language());
        }
 
        if (!reel_asset->entry_point()) {
-               notes.push_back ({VerificationNote::Type::BV21_ERROR, VerificationNote::Code::MISSING_SUBTITLE_ENTRY_POINT, reel_asset->id() });
+               context.bv21_error(VerificationNote::Code::MISSING_SUBTITLE_ENTRY_POINT, reel_asset->id());
        } else if (reel_asset->entry_point().get()) {
-               notes.push_back ({VerificationNote::Type::BV21_ERROR, VerificationNote::Code::INCORRECT_SUBTITLE_ENTRY_POINT, reel_asset->id() });
+               context.bv21_error(VerificationNote::Code::INCORRECT_SUBTITLE_ENTRY_POINT, reel_asset->id());
        }
 }
 
 
 static void
-verify_closed_caption_reel (shared_ptr<const ReelClosedCaptionAsset> reel_asset, vector<VerificationNote>& notes)
+verify_closed_caption_reel(Context& context, shared_ptr<const ReelClosedCaptionAsset> reel_asset)
 {
        /* XXX: is Language compulsory? */
        if (reel_asset->language()) {
-               verify_language_tag (*reel_asset->language(), notes);
+               verify_language_tag(context, *reel_asset->language());
        }
 
        if (!reel_asset->entry_point()) {
-               notes.push_back ({VerificationNote::Type::BV21_ERROR, VerificationNote::Code::MISSING_CLOSED_CAPTION_ENTRY_POINT, reel_asset->id() });
+               context.bv21_error(VerificationNote::Code::MISSING_CLOSED_CAPTION_ENTRY_POINT, reel_asset->id());
        } else if (reel_asset->entry_point().get()) {
-               notes.push_back ({VerificationNote::Type::BV21_ERROR, VerificationNote::Code::INCORRECT_CLOSED_CAPTION_ENTRY_POINT, reel_asset->id() });
+               context.bv21_error(VerificationNote::Code::INCORRECT_CLOSED_CAPTION_ENTRY_POINT, reel_asset->id());
        }
 }
 
@@ -711,22 +749,20 @@ verify_closed_caption_reel (shared_ptr<const ReelClosedCaptionAsset> reel_asset,
 /** Verify stuff that is common to both subtitles and closed captions */
 void
 verify_smpte_timed_text_asset (
+       Context& context,
        shared_ptr<const SMPTESubtitleAsset> asset,
-       optional<int64_t> reel_asset_duration,
-       vector<VerificationNote>& notes
+       optional<int64_t> reel_asset_duration
        )
 {
        if (asset->language()) {
-               verify_language_tag (*asset->language(), notes);
+               verify_language_tag(context, *asset->language());
        } else {
-               notes.push_back ({ VerificationNote::Type::BV21_ERROR, VerificationNote::Code::MISSING_SUBTITLE_LANGUAGE, *asset->file() });
+               context.bv21_error(VerificationNote::Code::MISSING_SUBTITLE_LANGUAGE, *asset->file());
        }
 
        auto const size = filesystem::file_size(asset->file().get());
        if (size > 115 * 1024 * 1024) {
-               notes.push_back (
-                       { VerificationNote::Type::BV21_ERROR, VerificationNote::Code::INVALID_TIMED_TEXT_SIZE_IN_BYTES, raw_convert<string>(size), *asset->file() }
-                       );
+               context.bv21_error(VerificationNote::Code::INVALID_TIMED_TEXT_SIZE_IN_BYTES, raw_convert<string>(size), *asset->file());
        }
 
        /* XXX: I'm not sure what Bv2.1_7.2.1 means when it says "the font resource shall not be larger than 10MB"
@@ -738,54 +774,48 @@ verify_smpte_timed_text_asset (
                total_size += i.second.size();
        }
        if (total_size > 10 * 1024 * 1024) {
-               notes.push_back ({ VerificationNote::Type::BV21_ERROR, VerificationNote::Code::INVALID_TIMED_TEXT_FONT_SIZE_IN_BYTES, raw_convert<string>(total_size), asset->file().get() });
+               context.bv21_error(VerificationNote::Code::INVALID_TIMED_TEXT_FONT_SIZE_IN_BYTES, raw_convert<string>(total_size), asset->file().get());
        }
 
        if (!asset->start_time()) {
-               notes.push_back ({ VerificationNote::Type::BV21_ERROR, VerificationNote::Code::MISSING_SUBTITLE_START_TIME, asset->file().get() });
+               context.bv21_error(VerificationNote::Code::MISSING_SUBTITLE_START_TIME, asset->file().get());
        } else if (asset->start_time() != Time()) {
-               notes.push_back ({ VerificationNote::Type::BV21_ERROR, VerificationNote::Code::INVALID_SUBTITLE_START_TIME, asset->file().get() });
+               context.bv21_error(VerificationNote::Code::INVALID_SUBTITLE_START_TIME, asset->file().get());
        }
 
        if (reel_asset_duration && *reel_asset_duration != asset->intrinsic_duration()) {
-               notes.push_back (
-                       {
-                               VerificationNote::Type::BV21_ERROR,
-                               VerificationNote::Code::MISMATCHED_TIMED_TEXT_DURATION,
-                               String::compose("%1 %2", *reel_asset_duration, asset->intrinsic_duration()),
-                               asset->file().get()
-                       });
+               context.bv21_error(
+                       VerificationNote::Code::MISMATCHED_TIMED_TEXT_DURATION,
+                       String::compose("%1 %2", *reel_asset_duration, asset->intrinsic_duration()),
+                       asset->file().get()
+                       );
        }
 }
 
 
 /** Verify Interop subtitle / CCAP stuff */
 void
-verify_interop_text_asset(shared_ptr<const InteropSubtitleAsset> asset, vector<VerificationNote>& notes)
+verify_interop_text_asset(Context& context, shared_ptr<const InteropSubtitleAsset> asset)
 {
        if (asset->subtitles().empty()) {
-               notes.push_back({VerificationNote::Type::ERROR, VerificationNote::Code::MISSING_SUBTITLE, asset->id(), asset->file().get() });
+               context.error(VerificationNote::Code::MISSING_SUBTITLE, asset->id(), asset->file().get());
        }
        auto const unresolved = asset->unresolved_fonts();
        if (!unresolved.empty()) {
-               notes.push_back({VerificationNote::Type::ERROR, VerificationNote::Code::MISSING_FONT, unresolved.front() });
+               context.error(VerificationNote::Code::MISSING_FONT, unresolved.front());
        }
 }
 
 
 /** Verify SMPTE subtitle-only stuff */
 void
-verify_smpte_subtitle_asset (
-       shared_ptr<const SMPTESubtitleAsset> asset,
-       vector<VerificationNote>& notes,
-       State& state
-       )
+verify_smpte_subtitle_asset(Context& context, shared_ptr<const SMPTESubtitleAsset> asset)
 {
        if (asset->language()) {
-               if (!state.subtitle_language) {
-                       state.subtitle_language = *asset->language();
-               } else if (state.subtitle_language != *asset->language()) {
-                       notes.push_back ({ VerificationNote::Type::BV21_ERROR, VerificationNote::Code::MISMATCHED_SUBTITLE_LANGUAGES });
+               if (!context.subtitle_language) {
+                       context.subtitle_language = *asset->language();
+               } else if (context.subtitle_language != *asset->language()) {
+                       context.bv21_error(VerificationNote::Code::MISMATCHED_SUBTITLE_LANGUAGES);
                }
        }
 
@@ -793,14 +823,14 @@ verify_smpte_subtitle_asset (
        auto xml_id = asset->xml_id();
        if (xml_id) {
                if (asset->resource_id().get() != xml_id) {
-                       notes.push_back ({ VerificationNote::Type::BV21_ERROR, VerificationNote::Code::MISMATCHED_TIMED_TEXT_RESOURCE_ID });
+                       context.bv21_error(VerificationNote::Code::MISMATCHED_TIMED_TEXT_RESOURCE_ID);
                }
 
                if (asset->id() == asset->resource_id().get() || asset->id() == xml_id) {
-                       notes.push_back ({ VerificationNote::Type::BV21_ERROR, VerificationNote::Code::INCORRECT_TIMED_TEXT_ASSET_ID });
+                       context.bv21_error(VerificationNote::Code::INCORRECT_TIMED_TEXT_ASSET_ID);
                }
        } else {
-               notes.push_back ({VerificationNote::Type::WARNING, VerificationNote::Code::MISSED_CHECK_OF_ENCRYPTED});
+               context.warning(VerificationNote::Code::MISSED_CHECK_OF_ENCRYPTED);
        }
 
        if (asset->raw_xml()) {
@@ -810,7 +840,7 @@ verify_smpte_subtitle_asset (
                auto issue_date = doc.string_child("IssueDate");
                std::regex reg("^\\d\\d\\d\\d-\\d\\d-\\d\\dT\\d\\d:\\d\\d:\\d\\d$");
                if (!std::regex_match(issue_date, reg)) {
-                       notes.push_back({VerificationNote::Type::WARNING, VerificationNote::Code::INVALID_SUBTITLE_ISSUE_DATE, issue_date});
+                       context.warning(VerificationNote::Code::INVALID_SUBTITLE_ISSUE_DATE, issue_date);
                }
        }
 }
@@ -818,23 +848,16 @@ verify_smpte_subtitle_asset (
 
 /** Verify all subtitle stuff */
 static void
-verify_subtitle_asset (
-       shared_ptr<const SubtitleAsset> asset,
-       optional<int64_t> reel_asset_duration,
-       function<void (string, optional<boost::filesystem::path>)> stage,
-       boost::filesystem::path xsd_dtd_directory,
-       vector<VerificationNote>& notes,
-       State& state
-       )
+verify_subtitle_asset(Context& context, shared_ptr<const SubtitleAsset> asset, optional<int64_t> reel_asset_duration)
 {
-       stage ("Checking subtitle XML", asset->file());
+       context.stage("Checking subtitle XML", asset->file());
        /* Note: we must not use SubtitleAsset::xml_as_string() here as that will mean the data on disk
         * gets passed through libdcp which may clean up and therefore hide errors.
         */
        if (asset->raw_xml()) {
-               validate_xml (asset->raw_xml().get(), xsd_dtd_directory, notes);
+               validate_xml(context, asset->raw_xml().get());
        } else {
-               notes.push_back ({VerificationNote::Type::WARNING, VerificationNote::Code::MISSED_CHECK_OF_ENCRYPTED});
+               context.warning(VerificationNote::Code::MISSED_CHECK_OF_ENCRYPTED);
        }
 
        auto namespace_count = [](shared_ptr<const SubtitleAsset> asset, string root_node) {
@@ -850,19 +873,19 @@ verify_subtitle_asset (
 
        auto interop = dynamic_pointer_cast<const InteropSubtitleAsset>(asset);
        if (interop) {
-               verify_interop_text_asset(interop, notes);
+               verify_interop_text_asset(context, interop);
                if (namespace_count(asset, "DCSubtitle") > 1) {
-                       notes.push_back({ VerificationNote::Type::WARNING, VerificationNote::Code::INCORRECT_SUBTITLE_NAMESPACE_COUNT, asset->id() });
+                       context.warning(VerificationNote::Code::INCORRECT_SUBTITLE_NAMESPACE_COUNT, asset->id());
                }
        }
 
        auto smpte = dynamic_pointer_cast<const SMPTESubtitleAsset>(asset);
        if (smpte) {
-               verify_smpte_timed_text_asset (smpte, reel_asset_duration, notes);
-               verify_smpte_subtitle_asset (smpte, notes, state);
+               verify_smpte_timed_text_asset(context, smpte, reel_asset_duration);
+               verify_smpte_subtitle_asset(context, smpte);
                /* This asset may be encrypted and in that case we'll have no raw_xml() */
                if (asset->raw_xml() && namespace_count(asset, "SubtitleReel") > 1) {
-                       notes.push_back({ VerificationNote::Type::WARNING, VerificationNote::Code::INCORRECT_SUBTITLE_NAMESPACE_COUNT, asset->id()});
+                       context.warning(VerificationNote::Code::INCORRECT_SUBTITLE_NAMESPACE_COUNT, asset->id());
                }
        }
 }
@@ -871,35 +894,33 @@ verify_subtitle_asset (
 /** Verify all closed caption stuff */
 static void
 verify_closed_caption_asset (
+       Context& context,
        shared_ptr<const SubtitleAsset> asset,
-       optional<int64_t> reel_asset_duration,
-       function<void (string, optional<boost::filesystem::path>)> stage,
-       boost::filesystem::path xsd_dtd_directory,
-       vector<VerificationNote>& notes
+       optional<int64_t> reel_asset_duration
        )
 {
-       stage ("Checking closed caption XML", asset->file());
+       context.stage("Checking closed caption XML", asset->file());
        /* Note: we must not use SubtitleAsset::xml_as_string() here as that will mean the data on disk
         * gets passed through libdcp which may clean up and therefore hide errors.
         */
        auto raw_xml = asset->raw_xml();
        if (raw_xml) {
-               validate_xml (*raw_xml, xsd_dtd_directory, notes);
+               validate_xml(context, *raw_xml);
                if (raw_xml->size() > 256 * 1024) {
-                       notes.push_back ({VerificationNote::Type::BV21_ERROR, VerificationNote::Code::INVALID_CLOSED_CAPTION_XML_SIZE_IN_BYTES, raw_convert<string>(raw_xml->size()), *asset->file()});
+                       context.bv21_error(VerificationNote::Code::INVALID_CLOSED_CAPTION_XML_SIZE_IN_BYTES, raw_convert<string>(raw_xml->size()), *asset->file());
                }
        } else {
-               notes.push_back ({VerificationNote::Type::WARNING, VerificationNote::Code::MISSED_CHECK_OF_ENCRYPTED});
+               context.warning(VerificationNote::Code::MISSED_CHECK_OF_ENCRYPTED);
        }
 
        auto interop = dynamic_pointer_cast<const InteropSubtitleAsset>(asset);
        if (interop) {
-               verify_interop_text_asset(interop, notes);
+               verify_interop_text_asset(context, interop);
        }
 
        auto smpte = dynamic_pointer_cast<const SMPTESubtitleAsset>(asset);
        if (smpte) {
-               verify_smpte_timed_text_asset (smpte, reel_asset_duration, notes);
+               verify_smpte_timed_text_asset(context, smpte, reel_asset_duration);
        }
 }
 
@@ -908,10 +929,9 @@ verify_closed_caption_asset (
 static
 void
 verify_text_details (
-       dcp::Standard standard,
+       Context& context,
        vector<shared_ptr<Reel>> reels,
        int edit_rate,
-       vector<VerificationNote>& notes,
        std::function<bool (shared_ptr<Reel>)> check,
        std::function<optional<string> (shared_ptr<Reel>)> xml,
        std::function<int64_t (shared_ptr<Reel>)> duration,
@@ -1005,7 +1025,7 @@ verify_text_details (
 
                auto reel_xml = xml(reels[i]);
                if (!reel_xml) {
-                       notes.push_back ({VerificationNote::Type::WARNING, VerificationNote::Code::MISSED_CHECK_OF_ENCRYPTED});
+                       context.warning(VerificationNote::Code::MISSED_CHECK_OF_ENCRYPTED);
                        continue;
                }
 
@@ -1016,7 +1036,7 @@ verify_text_details (
                shared_ptr<cxml::Document> doc;
                optional<int> tcr;
                optional<Time> start_time;
-               switch (standard) {
+               switch (context.dcp->standard().get_value_or(dcp::Standard::SMPTE)) {
                case dcp::Standard::INTEROP:
                        doc = make_shared<cxml::Document>("DCSubtitle");
                        doc->read_string (*reel_xml);
@@ -1039,8 +1059,8 @@ verify_text_details (
                }
                reel_offset = end;
 
-               if (standard == dcp::Standard::SMPTE && has_text && font_ids.empty()) {
-                       notes.push_back(dcp::VerificationNote(dcp::VerificationNote::Type::ERROR, VerificationNote::Code::MISSING_LOAD_FONT).set_id(id(reels[i])));
+               if (context.dcp->standard() && *context.dcp->standard() == dcp::Standard::SMPTE && has_text && font_ids.empty()) {
+                       context.add_note(dcp::VerificationNote(dcp::VerificationNote::Type::ERROR, VerificationNote::Code::MISSING_LOAD_FONT).set_id(id(reels[i])));
                }
        }
 
@@ -1049,47 +1069,34 @@ verify_text_details (
        }
 
        if (too_early) {
-               notes.push_back({
-                       VerificationNote::Type::WARNING, VerificationNote::Code::INVALID_SUBTITLE_FIRST_TEXT_TIME
-               });
+               context.warning(VerificationNote::Code::INVALID_SUBTITLE_FIRST_TEXT_TIME);
        }
 
        if (too_short) {
-               notes.push_back ({
-                       VerificationNote::Type::WARNING, VerificationNote::Code::INVALID_SUBTITLE_DURATION
-               });
+               context.warning(VerificationNote::Code::INVALID_SUBTITLE_DURATION);
        }
 
        if (too_close) {
-               notes.push_back ({
-                       VerificationNote::Type::WARNING, VerificationNote::Code::INVALID_SUBTITLE_SPACING
-               });
+               context.warning(VerificationNote::Code::INVALID_SUBTITLE_SPACING);
        }
 
        if (reel_overlap) {
-               notes.push_back ({
-                       VerificationNote::Type::ERROR, VerificationNote::Code::SUBTITLE_OVERLAPS_REEL_BOUNDARY
-               });
+               context.error(VerificationNote::Code::SUBTITLE_OVERLAPS_REEL_BOUNDARY);
        }
 
        if (empty_text) {
-               notes.push_back ({
-                       VerificationNote::Type::WARNING, VerificationNote::Code::EMPTY_TEXT
-               });
+               context.warning(VerificationNote::Code::EMPTY_TEXT);
        }
 
        if (missing_load_font_id) {
-               notes.push_back(dcp::VerificationNote(VerificationNote::Type::ERROR, VerificationNote::Code::MISSING_LOAD_FONT_FOR_FONT).set_id(*missing_load_font_id));
+               context.add_note(dcp::VerificationNote(VerificationNote::Type::ERROR, VerificationNote::Code::MISSING_LOAD_FONT_FOR_FONT).set_id(*missing_load_font_id));
        }
 }
 
 
 static
 void
-verify_closed_caption_details (
-       vector<shared_ptr<Reel>> reels,
-       vector<VerificationNote>& notes
-       )
+verify_closed_caption_details(Context& context, vector<shared_ptr<Reel>> reels)
 {
        std::function<void (cxml::ConstNodePtr node, std::vector<cxml::ConstNodePtr>& text_or_image)> find_text_or_image;
        find_text_or_image = [&find_text_or_image](cxml::ConstNodePtr node, std::vector<cxml::ConstNodePtr>& text_or_image) {
@@ -1155,7 +1162,7 @@ verify_closed_caption_details (
                for (auto ccap: reel->closed_captions()) {
                        auto reel_xml = ccap->asset()->raw_xml();
                        if (!reel_xml) {
-                               notes.push_back ({VerificationNote::Type::WARNING, VerificationNote::Code::MISSED_CHECK_OF_ENCRYPTED});
+                               context.warning(VerificationNote::Code::MISSED_CHECK_OF_ENCRYPTED);
                                continue;
                        }
 
@@ -1178,15 +1185,11 @@ verify_closed_caption_details (
        }
 
        if (mismatched_valign) {
-               notes.push_back ({
-                       VerificationNote::Type::ERROR, VerificationNote::Code::MISMATCHED_CLOSED_CAPTION_VALIGN,
-               });
+               context.error(VerificationNote::Code::MISMATCHED_CLOSED_CAPTION_VALIGN);
        }
 
        if (incorrect_order) {
-               notes.push_back ({
-                       VerificationNote::Type::ERROR, VerificationNote::Code::INCORRECT_CLOSED_CAPTION_ORDERING,
-               });
+               context.error(VerificationNote::Code::INCORRECT_CLOSED_CAPTION_ORDERING);
        }
 }
 
@@ -1292,14 +1295,14 @@ verify_text_lines_and_characters (
 
 static
 void
-verify_text_details(dcp::Standard standard, vector<shared_ptr<Reel>> reels, vector<VerificationNote>& notes)
+verify_text_details(Context& context, vector<shared_ptr<Reel>> reels)
 {
        if (reels.empty()) {
                return;
        }
 
        if (reels[0]->main_subtitle() && reels[0]->main_subtitle()->asset_ref().resolved()) {
-               verify_text_details(standard, reels, reels[0]->main_subtitle()->edit_rate().numerator, notes,
+               verify_text_details(context, reels, reels[0]->main_subtitle()->edit_rate().numerator,
                        [](shared_ptr<Reel> reel) {
                                return static_cast<bool>(reel->main_subtitle());
                        },
@@ -1316,7 +1319,7 @@ verify_text_details(dcp::Standard standard, vector<shared_ptr<Reel>> reels, vect
        }
 
        for (auto i = 0U; i < reels[0]->closed_captions().size(); ++i) {
-               verify_text_details(standard, reels, reels[0]->closed_captions()[i]->edit_rate().numerator, notes,
+               verify_text_details(context, reels, reels[0]->closed_captions()[i]->edit_rate().numerator,
                        [i](shared_ptr<Reel> reel) {
                                return i < reel->closed_captions().size();
                        },
@@ -1332,12 +1335,12 @@ verify_text_details(dcp::Standard standard, vector<shared_ptr<Reel>> reels, vect
                );
        }
 
-       verify_closed_caption_details (reels, notes);
+       verify_closed_caption_details(context, reels);
 }
 
 
 void
-verify_extension_metadata(shared_ptr<const CPL> cpl, vector<VerificationNote>& notes)
+verify_extension_metadata(Context& context, shared_ptr<const CPL> cpl)
 {
        DCP_ASSERT (cpl->file());
        cxml::Document doc ("CompositionPlaylist");
@@ -1387,9 +1390,9 @@ verify_extension_metadata(shared_ptr<const CPL> cpl, vector<VerificationNote>& n
        }
 
        if (missing) {
-               notes.push_back ({VerificationNote::Type::BV21_ERROR, VerificationNote::Code::MISSING_EXTENSION_METADATA, cpl->id(), cpl->file().get()});
+               context.bv21_error(VerificationNote::Code::MISSING_EXTENSION_METADATA, cpl->file().get());
        } else if (!malformed.empty()) {
-               notes.push_back ({VerificationNote::Type::BV21_ERROR, VerificationNote::Code::INVALID_EXTENSION_METADATA, malformed, cpl->file().get()});
+               context.bv21_error(VerificationNote::Code::INVALID_EXTENSION_METADATA, malformed, cpl->file().get());
        }
 }
 
@@ -1422,17 +1425,10 @@ pkl_has_encrypted_assets(shared_ptr<const DCP> dcp, shared_ptr<const PKL> pkl)
 static
 void
 verify_reel(
-       shared_ptr<const DCP> dcp,
-       shared_ptr<const CPL> cpl,
+       Context& context,
        shared_ptr<const Reel> reel,
        int64_t start_frame,
        optional<dcp::Size> main_picture_active_area,
-       function<void (string, optional<boost::filesystem::path>)> stage,
-       boost::filesystem::path xsd_dtd_directory,
-       function<void (float)> progress,
-       VerificationOptions options,
-       vector<VerificationNote>& notes,
-       State& state,
        bool* have_main_subtitle,
        bool* have_no_main_subtitle,
        size_t* most_closed_captions,
@@ -1442,24 +1438,24 @@ verify_reel(
 {
        for (auto i: reel->assets()) {
                if (i->duration() && (i->duration().get() * i->edit_rate().denominator / i->edit_rate().numerator) < 1) {
-                       notes.push_back({VerificationNote::Type::ERROR, VerificationNote::Code::INVALID_DURATION, i->id()});
+                       context.error(VerificationNote::Code::INVALID_DURATION, i->id());
                }
                if ((i->intrinsic_duration() * i->edit_rate().denominator / i->edit_rate().numerator) < 1) {
-                       notes.push_back({VerificationNote::Type::ERROR, VerificationNote::Code::INVALID_INTRINSIC_DURATION, i->id()});
+                       context.error(VerificationNote::Code::INVALID_INTRINSIC_DURATION, i->id());
                }
                auto file_asset = dynamic_pointer_cast<ReelFileAsset>(i);
                if (i->encryptable() && !file_asset->hash()) {
-                       notes.push_back({VerificationNote::Type::BV21_ERROR, VerificationNote::Code::MISSING_HASH, i->id()});
+                       context.bv21_error(VerificationNote::Code::MISSING_HASH, i->id());
                }
        }
 
-       if (dcp->standard() == Standard::SMPTE) {
+       if (context.dcp->standard() == Standard::SMPTE) {
                boost::optional<int64_t> duration;
                for (auto i: reel->assets()) {
                        if (!duration) {
                                duration = i->actual_duration();
                        } else if (*duration != i->actual_duration()) {
-                               notes.push_back({VerificationNote::Type::BV21_ERROR, VerificationNote::Code::MISMATCHED_ASSET_DURATION});
+                               context.bv21_error(VerificationNote::Code::MISMATCHED_ASSET_DURATION);
                                break;
                        }
                }
@@ -1476,32 +1472,26 @@ verify_reel(
                     frame_rate.numerator != 50 &&
                     frame_rate.numerator != 60 &&
                     frame_rate.numerator != 96)) {
-                       notes.push_back({
-                               VerificationNote::Type::ERROR,
-                               VerificationNote::Code::INVALID_PICTURE_FRAME_RATE,
-                               String::compose("%1/%2", frame_rate.numerator, frame_rate.denominator)
-                       });
+                       context.error(VerificationNote::Code::INVALID_PICTURE_FRAME_RATE, String::compose("%1/%2", frame_rate.numerator, frame_rate.denominator));
                }
                /* Check asset */
                if (reel->main_picture()->asset_ref().resolved()) {
-                       verify_main_picture_asset(dcp, reel->main_picture(), start_frame, stage, progress, options, notes);
+                       verify_main_picture_asset(context, reel->main_picture(), start_frame);
                        auto const asset_size = reel->main_picture()->asset()->size();
                        if (main_picture_active_area) {
                                if (main_picture_active_area->width > asset_size.width) {
-                                       notes.push_back({
-                                                       VerificationNote::Type::ERROR,
-                                                       VerificationNote::Code::INVALID_MAIN_PICTURE_ACTIVE_AREA,
-                                                       String::compose("width %1 is bigger than the asset width %2", main_picture_active_area->width, asset_size.width),
-                                                       cpl->file().get()
-                                                       });
+                                       context.error(
+                                               VerificationNote::Code::INVALID_MAIN_PICTURE_ACTIVE_AREA,
+                                               String::compose("width %1 is bigger than the asset width %2", main_picture_active_area->width, asset_size.width),
+                                               context.cpl->file().get()
+                                       );
                                }
                                if (main_picture_active_area->height > asset_size.height) {
-                                       notes.push_back({
-                                                       VerificationNote::Type::ERROR,
-                                                       VerificationNote::Code::INVALID_MAIN_PICTURE_ACTIVE_AREA,
-                                                       String::compose("height %1 is bigger than the asset height %2", main_picture_active_area->height, asset_size.height),
-                                                       cpl->file().get()
-                                                       });
+                                       context.error(
+                                               VerificationNote::Code::INVALID_MAIN_PICTURE_ACTIVE_AREA,
+                                               String::compose("height %1 is bigger than the asset height %2", main_picture_active_area->height, asset_size.height),
+                                               context.cpl->file().get()
+                                       );
                                }
                        }
                }
@@ -1509,13 +1499,13 @@ verify_reel(
        }
 
        if (reel->main_sound() && reel->main_sound()->asset_ref().resolved()) {
-               verify_main_sound_asset(dcp, reel->main_sound(), stage, progress, options, notes, state);
+               verify_main_sound_asset(context, reel->main_sound());
        }
 
        if (reel->main_subtitle()) {
-               verify_main_subtitle_reel(reel->main_subtitle(), notes);
+               verify_main_subtitle_reel(context, reel->main_subtitle());
                if (reel->main_subtitle()->asset_ref().resolved()) {
-                       verify_subtitle_asset(reel->main_subtitle()->asset(), reel->main_subtitle()->duration(), stage, xsd_dtd_directory, notes, state);
+                       verify_subtitle_asset(context, reel->main_subtitle()->asset(), reel->main_subtitle()->duration());
                }
                *have_main_subtitle = true;
        } else {
@@ -1523,9 +1513,9 @@ verify_reel(
        }
 
        for (auto i: reel->closed_captions()) {
-               verify_closed_caption_reel(i, notes);
+               verify_closed_caption_reel(context, i);
                if (i->asset_ref().resolved()) {
-                       verify_closed_caption_asset(i->asset(), i->duration(), stage, xsd_dtd_directory, notes);
+                       verify_closed_caption_asset(context, i->asset(), i->duration());
                }
        }
 
@@ -1534,10 +1524,10 @@ verify_reel(
                        markers_seen->insert(i);
                }
                if (reel->main_markers()->entry_point()) {
-                       notes.push_back({VerificationNote::Type::ERROR, VerificationNote::Code::UNEXPECTED_ENTRY_POINT});
+                       context.error(VerificationNote::Code::UNEXPECTED_ENTRY_POINT);
                }
                if (reel->main_markers()->duration()) {
-                       notes.push_back({VerificationNote::Type::ERROR, VerificationNote::Code::UNEXPECTED_DURATION});
+                       context.error(VerificationNote::Code::UNEXPECTED_DURATION);
                }
        }
 
@@ -1549,30 +1539,21 @@ verify_reel(
 
 static
 void
-verify_cpl(
-       shared_ptr<const DCP> dcp,
-       shared_ptr<const CPL> cpl,
-       function<void (string, optional<boost::filesystem::path>)> stage,
-       boost::filesystem::path xsd_dtd_directory,
-       function<void (float)> progress,
-       VerificationOptions options,
-       vector<VerificationNote>& notes,
-       State& state
-       )
+verify_cpl(Context& context, shared_ptr<const CPL> cpl)
 {
-       stage("Checking CPL", cpl->file());
-       validate_xml(cpl->file().get(), xsd_dtd_directory, notes);
+       context.stage("Checking CPL", cpl->file());
+       validate_xml(context, cpl->file().get());
 
        if (cpl->any_encrypted() && !cpl->all_encrypted()) {
-               notes.push_back({VerificationNote::Type::BV21_ERROR, VerificationNote::Code::PARTIALLY_ENCRYPTED});
+               context.bv21_error(VerificationNote::Code::PARTIALLY_ENCRYPTED);
        } else if (cpl->all_encrypted()) {
-               notes.push_back({VerificationNote::Type::OK, VerificationNote::Code::ALL_ENCRYPTED});
+               context.ok(VerificationNote::Code::ALL_ENCRYPTED);
        } else if (!cpl->all_encrypted()) {
-               notes.push_back({VerificationNote::Type::OK, VerificationNote::Code::NONE_ENCRYPTED});
+               context.ok(VerificationNote::Code::NONE_ENCRYPTED);
        }
 
        for (auto const& i: cpl->additional_subtitle_languages()) {
-               verify_language_tag(i, notes);
+               verify_language_tag(context, i);
        }
 
        if (!cpl->content_kind().scope() || *cpl->content_kind().scope() == "http://www.smpte-ra.org/schemas/429-7/2006/CPL#standard-content") {
@@ -1584,7 +1565,7 @@ verify_cpl(
                transform(name.begin(), name.end(), name.begin(), ::tolower);
                auto iter = std::find_if(all.begin(), all.end(), [name](ContentKind const& k) { return !k.scope() && k.name() == name; });
                if (iter == all.end()) {
-                       notes.push_back({VerificationNote::Type::ERROR, VerificationNote::Code::INVALID_CONTENT_KIND, cpl->content_kind().name()});
+                       context.error(VerificationNote::Code::INVALID_CONTENT_KIND, cpl->content_kind().name());
                }
        }
 
@@ -1597,7 +1578,7 @@ verify_cpl(
                                LanguageTag::RegionSubtag test(terr);
                        } catch (...) {
                                if (terr != "001") {
-                                       notes.push_back({VerificationNote::Type::BV21_ERROR, VerificationNote::Code::INVALID_LANGUAGE, terr});
+                                       context.bv21_error(VerificationNote::Code::INVALID_LANGUAGE, terr);
                                        valid = false;
                                }
                        }
@@ -1609,27 +1590,25 @@ verify_cpl(
 
        for (auto version: cpl->content_versions()) {
                if (version.label_text.empty()) {
-                       notes.push_back(
-                               dcp::VerificationNote(VerificationNote::Type::WARNING, VerificationNote::Code::EMPTY_CONTENT_VERSION_LABEL_TEXT, cpl->file().get()).set_id(cpl->id())
-                               );
+                       context.warning(VerificationNote::Code::EMPTY_CONTENT_VERSION_LABEL_TEXT, cpl->file().get());
                        break;
                }
        }
 
-       if (dcp->standard() == Standard::SMPTE) {
+       if (context.dcp->standard() == Standard::SMPTE) {
                if (!cpl->annotation_text()) {
-                       notes.push_back({VerificationNote::Type::BV21_ERROR, VerificationNote::Code::MISSING_CPL_ANNOTATION_TEXT, cpl->id(), cpl->file().get()});
+                       context.bv21_error(VerificationNote::Code::MISSING_CPL_ANNOTATION_TEXT, cpl->file().get());
                } else if (cpl->annotation_text().get() != cpl->content_title_text()) {
-                       notes.push_back({VerificationNote::Type::WARNING, VerificationNote::Code::MISMATCHED_CPL_ANNOTATION_TEXT, cpl->id(), cpl->file().get()});
+                       context.warning(VerificationNote::Code::MISMATCHED_CPL_ANNOTATION_TEXT, cpl->file().get());
                }
        }
 
-       for (auto i: dcp->pkls()) {
+       for (auto i: context.dcp->pkls()) {
                /* Check that the CPL's hash corresponds to the PKL */
                optional<string> h = i->hash(cpl->id());
                auto calculated_cpl_hash = make_digest(ArrayData(*cpl->file()));
                if (h && calculated_cpl_hash != *h) {
-                       notes.push_back(
+                       context.notes.push_back(
                                dcp::VerificationNote(
                                        VerificationNote::Type::ERROR,
                                        VerificationNote::Code::MISMATCHED_CPL_HASHES,
@@ -1638,14 +1617,14 @@ verify_cpl(
                                        ).set_calculated_hash(calculated_cpl_hash).set_reference_hash(*h)
                                );
                } else {
-                       notes.push_back({VerificationNote::Type::OK, VerificationNote::Code::MATCHING_CPL_HASHES});
+                       context.ok(VerificationNote::Code::MATCHING_CPL_HASHES);
                }
 
                /* Check that any PKL with a single CPL has its AnnotationText the same as the CPL's ContentTitleText */
                optional<string> required_annotation_text;
                for (auto j: i->assets()) {
                        /* See if this is a CPL */
-                       for (auto k: dcp->cpls()) {
+                       for (auto k: context.dcp->cpls()) {
                                if (j->id() == k->id()) {
                                        if (!required_annotation_text) {
                                                /* First CPL we have found; this is the required AnnotationText unless we find another */
@@ -1659,7 +1638,7 @@ verify_cpl(
                }
 
                if (required_annotation_text && i->annotation_text() != required_annotation_text) {
-                       notes.push_back({VerificationNote::Type::BV21_ERROR, VerificationNote::Code::MISMATCHED_PKL_ANNOTATION_TEXT_WITH_CPL, i->id(), i->file().get()});
+                       context.bv21_error(VerificationNote::Code::MISMATCHED_PKL_ANNOTATION_TEXT_WITH_CPL, i->id(), i->file().get());
                }
        }
 
@@ -1675,37 +1654,28 @@ verify_cpl(
 
        auto const main_picture_active_area = cpl->main_picture_active_area();
        if (main_picture_active_area && (main_picture_active_area->width % 2)) {
-               notes.push_back({
-                               VerificationNote::Type::ERROR,
-                               VerificationNote::Code::INVALID_MAIN_PICTURE_ACTIVE_AREA,
-                               String::compose("width %1 is not a multiple of 2", main_picture_active_area->width),
-                               cpl->file().get()
-                       });
+               context.error(
+                       VerificationNote::Code::INVALID_MAIN_PICTURE_ACTIVE_AREA,
+                       String::compose("width %1 is not a multiple of 2", main_picture_active_area->width),
+                       cpl->file().get()
+                    );
        }
        if (main_picture_active_area && (main_picture_active_area->height % 2)) {
-               notes.push_back({
-                               VerificationNote::Type::ERROR,
-                               VerificationNote::Code::INVALID_MAIN_PICTURE_ACTIVE_AREA,
-                               String::compose("height %1 is not a multiple of 2", main_picture_active_area->height),
-                               cpl->file().get()
-                       });
+               context.error(
+                       VerificationNote::Code::INVALID_MAIN_PICTURE_ACTIVE_AREA,
+                       String::compose("height %1 is not a multiple of 2", main_picture_active_area->height),
+                       cpl->file().get()
+                    );
        }
 
        int64_t frame = 0;
        for (auto reel: cpl->reels()) {
-               stage("Checking reel", optional<boost::filesystem::path>());
+               context.stage("Checking reel", optional<boost::filesystem::path>());
                verify_reel(
-                       dcp,
-                       cpl,
+                       context,
                        reel,
                        frame,
                        main_picture_active_area,
-                       stage,
-                       xsd_dtd_directory,
-                       progress,
-                       options,
-                       notes,
-                       state,
                        &have_main_subtitle,
                        &have_no_main_subtitle,
                        &most_closed_captions,
@@ -1715,51 +1685,50 @@ verify_cpl(
                frame += reel->duration();
        }
 
-       verify_text_details(dcp->standard().get_value_or(dcp::Standard::SMPTE), cpl->reels(), notes);
+       verify_text_details(context, cpl->reels());
 
-       if (dcp->standard() == Standard::SMPTE) {
+       if (context.dcp->standard() == Standard::SMPTE) {
                if (auto msc = cpl->main_sound_configuration()) {
-                       if (state.audio_channels && msc->channels() != *state.audio_channels) {
-                               notes.push_back({
-                                               VerificationNote::Type::ERROR,
-                                               VerificationNote::Code::INVALID_MAIN_SOUND_CONFIGURATION,
-                                               String::compose("MainSoundConfiguration has %1 channels but sound assets have %2", msc->channels(), *state.audio_channels),
-                                               cpl->file().get()
-                                       });
+                       if (context.audio_channels && msc->channels() != *context.audio_channels) {
+                               context.error(
+                                       VerificationNote::Code::INVALID_MAIN_SOUND_CONFIGURATION,
+                                       String::compose("MainSoundConfiguration has %1 channels but sound assets have %2", msc->channels(), *context.audio_channels),
+                                       cpl->file().get()
+                               );
                        }
                }
 
                if (have_main_subtitle && have_no_main_subtitle) {
-                       notes.push_back({VerificationNote::Type::BV21_ERROR, VerificationNote::Code::MISSING_MAIN_SUBTITLE_FROM_SOME_REELS});
+                       context.bv21_error(VerificationNote::Code::MISSING_MAIN_SUBTITLE_FROM_SOME_REELS);
                }
 
                if (fewest_closed_captions != most_closed_captions) {
-                       notes.push_back({VerificationNote::Type::BV21_ERROR, VerificationNote::Code::MISMATCHED_CLOSED_CAPTION_ASSET_COUNTS});
+                       context.bv21_error(VerificationNote::Code::MISMATCHED_CLOSED_CAPTION_ASSET_COUNTS);
                }
 
                if (cpl->content_kind() == ContentKind::FEATURE) {
                        if (markers_seen.find(Marker::FFEC) == markers_seen.end()) {
-                               notes.push_back({VerificationNote::Type::BV21_ERROR, VerificationNote::Code::MISSING_FFEC_IN_FEATURE});
+                               context.bv21_error(VerificationNote::Code::MISSING_FFEC_IN_FEATURE);
                        }
                        if (markers_seen.find(Marker::FFMC) == markers_seen.end()) {
-                               notes.push_back({VerificationNote::Type::BV21_ERROR, VerificationNote::Code::MISSING_FFMC_IN_FEATURE});
+                               context.bv21_error(VerificationNote::Code::MISSING_FFMC_IN_FEATURE);
                        }
                }
 
                auto ffoc = markers_seen.find(Marker::FFOC);
                if (ffoc == markers_seen.end()) {
-                       notes.push_back({VerificationNote::Type::WARNING, VerificationNote::Code::MISSING_FFOC});
+                       context.warning(VerificationNote::Code::MISSING_FFOC);
                } else if (ffoc->second.e != 1) {
-                       notes.push_back({VerificationNote::Type::WARNING, VerificationNote::Code::INCORRECT_FFOC, raw_convert<string>(ffoc->second.e)});
+                       context.warning(VerificationNote::Code::INCORRECT_FFOC, raw_convert<string>(ffoc->second.e));
                }
 
                auto lfoc = markers_seen.find(Marker::LFOC);
                if (lfoc == markers_seen.end()) {
-                       notes.push_back({VerificationNote::Type::WARNING, VerificationNote::Code::MISSING_LFOC});
+                       context.warning(VerificationNote::Code::MISSING_LFOC);
                } else {
                        auto lfoc_time = lfoc->second.as_editable_units_ceil(lfoc->second.tcr);
                        if (lfoc_time != (cpl->reels().back()->duration() - 1)) {
-                               notes.push_back({VerificationNote::Type::WARNING, VerificationNote::Code::INCORRECT_LFOC, raw_convert<string>(lfoc_time)});
+                               context.warning(VerificationNote::Code::INCORRECT_LFOC, raw_convert<string>(lfoc_time));
                        }
                }
 
@@ -1771,12 +1740,12 @@ verify_cpl(
                }
 
                if (result.line_count_exceeded) {
-                       notes.push_back({VerificationNote::Type::WARNING, VerificationNote::Code::INVALID_SUBTITLE_LINE_COUNT});
+                       context.warning(VerificationNote::Code::INVALID_SUBTITLE_LINE_COUNT);
                }
                if (result.error_length_exceeded) {
-                       notes.push_back({VerificationNote::Type::WARNING, VerificationNote::Code::INVALID_SUBTITLE_LINE_LENGTH});
+                       context.warning(VerificationNote::Code::INVALID_SUBTITLE_LINE_LENGTH);
                } else if (result.warning_length_exceeded) {
-                       notes.push_back({VerificationNote::Type::WARNING, VerificationNote::Code::NEARLY_INVALID_SUBTITLE_LINE_LENGTH});
+                       context.warning(VerificationNote::Code::NEARLY_INVALID_SUBTITLE_LINE_LENGTH);
                }
 
                result = LinesCharactersResult();
@@ -1789,26 +1758,26 @@ verify_cpl(
                }
 
                if (result.line_count_exceeded) {
-                       notes.push_back({VerificationNote::Type::BV21_ERROR, VerificationNote::Code::INVALID_CLOSED_CAPTION_LINE_COUNT});
+                       context.bv21_error(VerificationNote::Code::INVALID_CLOSED_CAPTION_LINE_COUNT);
                }
                if (result.error_length_exceeded) {
-                       notes.push_back({VerificationNote::Type::BV21_ERROR, VerificationNote::Code::INVALID_CLOSED_CAPTION_LINE_LENGTH});
+                       context.bv21_error(VerificationNote::Code::INVALID_CLOSED_CAPTION_LINE_LENGTH);
                }
 
                if (!cpl->read_composition_metadata()) {
-                       notes.push_back({VerificationNote::Type::BV21_ERROR, VerificationNote::Code::MISSING_CPL_METADATA, cpl->id(), cpl->file().get()});
+                       context.bv21_error(VerificationNote::Code::MISSING_CPL_METADATA, cpl->file().get());
                } else if (!cpl->version_number()) {
-                       notes.push_back({VerificationNote::Type::BV21_ERROR, VerificationNote::Code::MISSING_CPL_METADATA_VERSION_NUMBER, cpl->id(), cpl->file().get()});
+                       context.bv21_error(VerificationNote::Code::MISSING_CPL_METADATA_VERSION_NUMBER, cpl->file().get());
                }
 
-               verify_extension_metadata(cpl, notes);
+               verify_extension_metadata(context, cpl);
 
                if (cpl->any_encrypted()) {
                        cxml::Document doc("CompositionPlaylist");
                        DCP_ASSERT(cpl->file());
                        doc.read_file(dcp::filesystem::fix_long_path(cpl->file().get()));
                        if (!doc.optional_node_child("Signature")) {
-                               notes.push_back({VerificationNote::Type::BV21_ERROR, VerificationNote::Code::UNSIGNED_CPL_WITH_ENCRYPTED_CONTENT, cpl->id(), cpl->file().get()});
+                               context.bv21_error(VerificationNote::Code::UNSIGNED_CPL_WITH_ENCRYPTED_CONTENT, cpl->file().get());
                        }
                }
        }
@@ -1817,27 +1786,22 @@ verify_cpl(
 
 static
 void
-verify_pkl(
-       shared_ptr<const DCP> dcp,
-       shared_ptr<const PKL> pkl,
-       boost::filesystem::path xsd_dtd_directory,
-       vector<VerificationNote>& notes
-       )
+verify_pkl(Context& context, shared_ptr<const PKL> pkl)
 {
-       validate_xml(pkl->file().get(), xsd_dtd_directory, notes);
+       validate_xml(context, pkl->file().get());
 
-       if (pkl_has_encrypted_assets(dcp, pkl)) {
+       if (pkl_has_encrypted_assets(context.dcp, pkl)) {
                cxml::Document doc("PackingList");
                doc.read_file(dcp::filesystem::fix_long_path(pkl->file().get()));
                if (!doc.optional_node_child("Signature")) {
-                       notes.push_back({VerificationNote::Type::BV21_ERROR, VerificationNote::Code::UNSIGNED_PKL_WITH_ENCRYPTED_CONTENT, pkl->id(), pkl->file().get()});
+                       context.bv21_error(VerificationNote::Code::UNSIGNED_PKL_WITH_ENCRYPTED_CONTENT, pkl->id(), pkl->file().get());
                }
        }
 
        set<string> uuid_set;
        for (auto asset: pkl->assets()) {
                if (!uuid_set.insert(asset->id()).second) {
-                       notes.push_back({VerificationNote::Type::ERROR, VerificationNote::Code::DUPLICATE_ASSET_ID_IN_PKL, pkl->id(), pkl->file().get()});
+                       context.error(VerificationNote::Code::DUPLICATE_ASSET_ID_IN_PKL, pkl->id(), pkl->file().get());
                        break;
                }
        }
@@ -1847,21 +1811,17 @@ verify_pkl(
 
 static
 void
-verify_assetmap(
-       shared_ptr<const DCP> dcp,
-       boost::filesystem::path xsd_dtd_directory,
-       vector<VerificationNote>& notes
-       )
+verify_assetmap(Context& context, shared_ptr<const DCP> dcp)
 {
        auto asset_map = dcp->asset_map();
        DCP_ASSERT(asset_map);
 
-       validate_xml(asset_map->file().get(), xsd_dtd_directory, notes);
+       validate_xml(context, asset_map->file().get());
 
        set<string> uuid_set;
        for (auto const& asset: asset_map->assets()) {
                if (!uuid_set.insert(asset.id()).second) {
-                       notes.push_back({VerificationNote::Type::ERROR, VerificationNote::Code::DUPLICATE_ASSET_ID_IN_ASSETMAP, asset_map->id(), asset_map->file().get()});
+                       context.error(VerificationNote::Code::DUPLICATE_ASSET_ID_IN_ASSETMAP, asset_map->id(), asset_map->file().get());
                        break;
                }
        }
@@ -1884,7 +1844,7 @@ dcp::verify (
        *xsd_dtd_directory = filesystem::canonical(*xsd_dtd_directory);
 
        vector<VerificationNote> notes;
-       State state{};
+       Context context(notes, *xsd_dtd_directory, stage, progress, options);
 
        vector<shared_ptr<DCP>> dcps;
        for (auto i: directories) {
@@ -1893,22 +1853,25 @@ dcp::verify (
 
        for (auto dcp: dcps) {
                stage ("Checking DCP", dcp->directory());
+
+               context.dcp = dcp;
+
                bool carry_on = true;
                try {
                        dcp->read (&notes, true);
                } catch (MissingAssetmapError& e) {
-                       notes.push_back ({VerificationNote::Type::ERROR, VerificationNote::Code::FAILED_READ, string(e.what())});
+                       context.error(VerificationNote::Code::FAILED_READ, string(e.what()));
                        carry_on = false;
                } catch (ReadError& e) {
-                       notes.push_back ({VerificationNote::Type::ERROR, VerificationNote::Code::FAILED_READ, string(e.what())});
+                       context.error(VerificationNote::Code::FAILED_READ, string(e.what()));
                } catch (XMLError& e) {
-                       notes.push_back ({VerificationNote::Type::ERROR, VerificationNote::Code::FAILED_READ, string(e.what())});
+                       context.error(VerificationNote::Code::FAILED_READ, string(e.what()));
                } catch (MXFFileError& e) {
-                       notes.push_back ({VerificationNote::Type::ERROR, VerificationNote::Code::FAILED_READ, string(e.what())});
+                       context.error(VerificationNote::Code::FAILED_READ, string(e.what()));
                } catch (BadURNUUIDError& e) {
-                       notes.push_back({VerificationNote::Type::ERROR, VerificationNote::Code::FAILED_READ, string(e.what())});
+                       context.error(VerificationNote::Code::FAILED_READ, string(e.what()));
                } catch (cxml::Error& e) {
-                       notes.push_back ({VerificationNote::Type::ERROR, VerificationNote::Code::FAILED_READ, string(e.what())});
+                       context.error(VerificationNote::Code::FAILED_READ, string(e.what()));
                }
 
                if (!carry_on) {
@@ -1925,16 +1888,7 @@ dcp::verify (
 
                for (auto cpl: dcp->cpls()) {
                        try {
-                               verify_cpl(
-                                       dcp,
-                                       cpl,
-                                       stage,
-                                       *xsd_dtd_directory,
-                                       progress,
-                                       options,
-                                       notes,
-                                       state
-                                       );
+                               verify_cpl(context, cpl);
                        } catch (ReadError& e) {
                                notes.push_back({VerificationNote::Type::ERROR, VerificationNote::Code::FAILED_READ, string(e.what())});
                        }
@@ -1942,14 +1896,14 @@ dcp::verify (
 
                for (auto pkl: dcp->pkls()) {
                        stage("Checking PKL", pkl->file());
-                       verify_pkl(dcp, pkl, *xsd_dtd_directory, notes);
+                       verify_pkl(context, pkl);
                }
 
                if (dcp->asset_map_file()) {
                        stage("Checking ASSETMAP", dcp->asset_map_file().get());
-                       verify_assetmap(dcp, *xsd_dtd_directory, notes);
+                       verify_assetmap(context, dcp);
                } else {
-                       notes.push_back ({VerificationNote::Type::ERROR, VerificationNote::Code::MISSING_ASSETMAP});
+                       context.error(VerificationNote::Code::MISSING_ASSETMAP);
                }
        }