small improvements

- fixed some mostly ID3/MP3 related bugs
- added convenience methods/operators

basicfileinfo.cpp

@@ -58,7 +58,7 @@ void BasicFileInfo::open(bool readOnly)
  */
 void BasicFileInfo::reopen(bool readOnly)
 {
-    close();
+    invalidated();
     m_file.open(m_path, (m_readOnly = readOnly) ? ios_base::in | ios_base::binary : ios_base::in | ios_base::out | ios_base::binary);
     m_file.seekg(0, ios_base::end);
     m_size = m_file.tellg();
@@ -76,6 +76,14 @@ void BasicFileInfo::close()
     m_file.clear();
 }
 
+/*!
+ * \brief Invalidates the file info manually.
+ */
+void BasicFileInfo::invalidate()
+{
+    invalidated();
+}
+
 /*!
  * \brief Sets the current file.
  *
@@ -202,7 +210,7 @@ string BasicFileInfo::containingDirectory() const
 
 /*!
  * \brief This function is called when the BasicFileInfo gets invalidated.
- *        This is the case when the current file changes.
+ *        This is the case when the current file changes or is reopened.
  *
  * When subclassing and overwriting this virtual method invoke the base
  * implementation by calling BasicFileInfo::invalidated() before the reimplemented code.
@@ -210,7 +218,6 @@ string BasicFileInfo::containingDirectory() const
 void BasicFileInfo::invalidated()
 {
     m_size = 0;
-    m_path.clear();
     close();
 }
 

basicfileinfo.h

@@ -22,6 +22,7 @@ public:
     bool isOpen() const;
     bool isReadOnly() const;
     void close();
+    void invalidate();
 
     const std::string &path() const;
     void setPath(const std::string &path);

id3/id3v1tag.cpp

@@ -123,7 +123,7 @@ void Id3v1Tag::make(ostream &stream)
     // track
     try {
     if(!m_trackPos.isEmpty() && m_trackPos.type() == TagDataType::PositionInSet)
-        buffer[1] = m_trackPos.toPositionIntSet().position();
+        buffer[1] = m_trackPos.toPositionInSet().position();
     } catch(ConversionException &) {
         addNotification(NotificationType::Warning, "Track position field can not be set because given value can not be converted appropriately.", context);
     }

id3/id3v2frame.cpp

@@ -108,6 +108,7 @@ int parseGenreIndex(const stringtype &denotation, bool isBigEndian = false)
 void Id3v2Frame::parse(BinaryReader &reader, const uint32 version, const uint32 maximalSize)
 {
     invalidateStatus();
+    clear();
     string context("parsing ID3v2 frame");
 
     // parse header
@@ -115,13 +116,13 @@ void Id3v2Frame::parse(BinaryReader &reader, const uint32 version, const uint32
         // parse header for ID3v2.1 and ID3v2.2
         // -> read ID
         setId(reader.readUInt24BE());
-        if((id() & 0xFFFF0000u) == 0) {
+        if(id() & 0xFFFF0000u) {
+            m_padding = false;
+        } else {
             // padding reached
             m_padding = true;
             addNotification(NotificationType::Debug, "Frame ID starts with null-byte -> padding reached.", context);
             throw NoDataFoundException();
-        } else {
-            m_padding = false;
         }
 
         // -> update context
@@ -143,13 +144,13 @@ void Id3v2Frame::parse(BinaryReader &reader, const uint32 version, const uint32
         // parse header for ID3v2.3 and ID3v2.4
         // -> read ID
         setId(reader.readUInt32BE());
-        if((id() & 0xFF000000u) == 0) {
+        if(id() & 0xFF000000u) {
+            m_padding = false;
+        } else {
             // padding reached
             m_padding = true;
             addNotification(NotificationType::Debug, "Frame ID starts with null-byte -> padding reached.", context);
             throw NoDataFoundException();
-        } else {
-            m_padding = false;
         }
 
         // -> update context
@@ -232,7 +233,7 @@ void Id3v2Frame::parse(BinaryReader &reader, const uint32 version, const uint32
                     position = PositionInSet(parseString(buffer.get() + 1, m_dataSize - 1, dataEncoding));
                 }
                 value().assignPosition(position);
-            } catch(ConversionException &) {
+            } catch(const ConversionException &) {
                 addNotification(NotificationType::Warning, "The value of track/disk position frame is not numeric and will be ignored.", context);
             }
 
@@ -246,7 +247,7 @@ void Id3v2Frame::parse(BinaryReader &reader, const uint32 version, const uint32
                     milliseconds = ConversionUtilities::stringToNumber<double>(parseString(buffer.get() + 1, m_dataSize - 1, dataEncoding), 10);
                 }
                 value().assignTimeSpan(TimeSpan::fromMilliseconds(milliseconds));
-            } catch (ConversionException &) {
+            } catch (const ConversionException &) {
                 addNotification(NotificationType::Warning, "The value of the length frame is not numeric and will be ignored.", context);
             }
 
@@ -440,7 +441,7 @@ Id3v2FrameMaker::Id3v2FrameMaker(Id3v2Frame &frame, const byte version) :
             // just write the data
             copy(m_frame.value().dataPointer(), m_frame.value().dataPointer() + m_decompressedSize, m_data.get());
         }
-    } catch(ConversionException &) {
+    } catch(const ConversionException &) {
         m_frame.addNotification(NotificationType::Critical, "Assigned value can not be converted appropriately.", context);
         throw InvalidDataException();
     }
@@ -739,21 +740,23 @@ void Id3v2Frame::parsePicture(const char *buffer, size_t maxSize, TagValue &tagV
 }
 
 /*!
- * \brief Parses the comment from the specified \a buffer.
+ * \brief Parses the comment/unsynchronized lyrics from the specified \a buffer.
  * \param buffer Specifies the buffer holding the picture.
  * \param dataSize Specifies the maximal number of bytes to read from the buffer.
  * \param tagValue Specifies the tag value used to store the results.
  */
 void Id3v2Frame::parseComment(const char *buffer, size_t dataSize, TagValue &tagValue)
 {
-    static const string context("parsing comment frame");
+    static const string context("parsing comment/unsynchronized lyrics frame");
     const char *end = buffer + dataSize;
     if(dataSize < 6) {
         addNotification(NotificationType::Critical, "Comment frame is incomplete.", context);
         throw TruncatedDataException();
     }
     TagTextEncoding dataEncoding = parseTextEncodingByte(*buffer);
-    tagValue.setLanguage(string(++buffer, 3));
+    if(*(++buffer)) {
+        tagValue.setLanguage(string(buffer, 3));
+    }
     auto substr = parseSubstring(buffer += 3, dataSize -= 4, dataEncoding, true);
     tagValue.setDescription(string(get<0>(substr), get<1>(substr)), dataEncoding);
     if(get<2>(substr) >= end) {

id3/id3v2frameids.h

@@ -21,7 +21,6 @@ enum KnownValue : uint32 {
     lEncoder = 0x54454e43,
     lBpm = 0x5442504d,
     lCover = 0x41504943,
-    //lPerformers = 0x54504532,
     lWriter = 0x54455854,
     lLength = 0x544c454e,
     lLanguage = 0x544c414e,
@@ -45,7 +44,6 @@ enum KnownValue : uint32 {
     sEncoder = 0x54454e,
     sBpm = 0x544250,
     sCover = 0x504943,
-    //sPerformers = 0x545032,
     sWriter = 0x545854,
     sLength = 0x544c45,
     sLanguage = 0x544c41,

matroska/matroskatagid.h

@@ -204,7 +204,7 @@ inline LIB_EXPORT const char *icra() {
 }
 
 inline LIB_EXPORT const char *dateRelease() {
-    return "DATE_RELEASE";
+    return "DATE_RELEASED";
 }
 inline LIB_EXPORT const char *dateRecorded() {
     return "DATE_RECORDED";

mediafileinfo.cpp

@@ -920,7 +920,7 @@ bool MediaFileInfo::removeAllId3v2Tags()
  */
 Id3v2Tag *MediaFileInfo::createId3v2Tag()
 {
-    if(!m_id3v2Tags.size()) {
+    if(m_id3v2Tags.empty()) {
         m_id3v2Tags.emplace_back(make_unique<Id3v2Tag>());
     }
     return m_id3v2Tags.front().get();
@@ -1048,9 +1048,7 @@ bool MediaFileInfo::areTagsSupported() const
 
 /*!
  * \brief Returns a pointer to the assigned MP4 tag or nullptr if none is assigned.
- *
+ * \remarks The MediaFileInfo keeps the ownership over the object which will be destroyed when the
- * \remarks The MediaFileInfo keeps the ownership over the returned
- *          pointer. The returned MP4 tag will be destroyed when the
  *          MediaFileInfo is invalidated.
  */
 Mp4Tag *MediaFileInfo::mp4Tag() const
@@ -1061,7 +1059,6 @@ Mp4Tag *MediaFileInfo::mp4Tag() const
 
 /*!
  * \brief Returns pointers to the assigned Matroska tags.
- *
  * \remarks The MediaFileInfo keeps the ownership over the returned
  *          pointers. The returned Matroska tags will be destroyed when the
  *          MediaFileInfo is invalidated.
@@ -1077,11 +1074,20 @@ const vector<unique_ptr<MatroskaTag> > &MediaFileInfo::matroskaTags() const
     }
 }
 
+/*!
+ * \brief Returns a pointer to the first assigned Vorbis comment or nullptr if none is assigned.
+ * \remarks The MediaFileInfo keeps the ownership over the object which will be destroyed when the
+ *          MediaFileInfo is invalidated.
+ */
+VorbisComment *MediaFileInfo::vorbisComment() const
+{
+    return m_containerFormat == ContainerFormat::Ogg && m_container && m_container->tagCount() > 0 ? static_cast<OggContainer *>(m_container.get())->tags().front().get() : nullptr;
+}
+
 /*!
  * \brief Returns all chapters assigned to the current file.
- *
+ * \remarks The MediaFileInfo keeps the ownership over the object which will be destroyed when the
- * \remarks The MediaFileInfo keeps the ownership over the chapters which will be
+ *          MediaFileInfo is invalidated.
- *          destroyed when the MediaFileInfo is invalidated.
  */
 vector<AbstractChapter *> MediaFileInfo::chapters() const
 {
@@ -1098,9 +1104,8 @@ vector<AbstractChapter *> MediaFileInfo::chapters() const
 
 /*!
  * \brief Returns all attachments assigned to the current file.
- *
+ * \remarks The MediaFileInfo keeps the ownership over the object which will be destroyed when the
- * \remarks The MediaFileInfo keeps the ownership over the attachments which will be
+ *          MediaFileInfo is invalidated.
- *          destroyed when the MediaFileInfo is invalidated.
  */
 vector<AbstractAttachment *> MediaFileInfo::attachments() const
 {
@@ -1184,7 +1189,6 @@ NotificationType MediaFileInfo::worstNotificationTypeIncludingRelatedObjects() c
 /*!
  * \brief Returns the notifications of the current instance and all related
  *        objects (tracks, tags, container, ...).
- *
  * \remarks The specified list is not cleared before notifications are added.
  */
 void MediaFileInfo::gatherRelatedNotifications(NotificationList &notifications) const
@@ -1390,23 +1394,32 @@ void MediaFileInfo::makeMp3File()
             addNotifications(*tag);
         }
 
-        // determine padding, check whether rewrite is required
+        // check whether rewrite is required
         bool rewriteRequired = isForcingRewrite() || (tagsSize > static_cast<uint32>(m_containerOffset));
-        uint32 padding;
+        uint32 padding = 0;
         if(!rewriteRequired) {
+            // rewriting is not forced and new tag is not too big for available space
+            // -> calculate new padding
             padding = static_cast<uint32>(m_containerOffset) - tagsSize;
-            // check whether padding matches specifications
+            // -> check whether the new padding matches specifications
             if(padding < minPadding() || padding > maxPadding()) {
                 rewriteRequired = true;
             }
         }
-        if(rewriteRequired) {
+        if(makers.empty()) {
-            // use preferred padding when rewriting
+            // an ID3v2 tag shouldn't be written
+            // -> can't include padding
+            if(padding) {
+                // but padding would be present -> need to rewrite
+                padding = 0;
+                rewriteRequired = true;
+            }
+        } else if(rewriteRequired) {
+            // rewriting is forced or new ID3v2 tag is too big for available space
+            // -> use preferred padding when rewriting anyways
             padding = preferredPadding();
-            updateStatus("Preparing streams for rewriting ...");
-        } else {
-            updateStatus("Preparing streams for updating ...");
         }
+        updateStatus(rewriteRequired ? "Preparing streams for rewriting ..." : "Preparing streams for updating ...");
 
         // setup stream(s) for writing
         // -> define variables needed to handle output stream and backup stream (required when rewriting the file)
@@ -1449,7 +1462,7 @@ void MediaFileInfo::makeMp3File()
                 // include padding into the last ID3v2 tag
                 makers.back().make(outputStream, padding);
             } else {
-                // no ID3v2 tags assigned -> just write padding
+                // just write padding
                 for(; padding; --padding) {
                     outputStream.put(0);
                 }

mediafileinfo.h

@@ -26,6 +26,7 @@ class MatroskaTag;
 class AbstractTrack;
 class WaveAudioStream;
 class MpegAudioFrameStream;
+class VorbisComment;
 
 enum class MediaType;
 enum class TagType : unsigned int;
@@ -117,6 +118,7 @@ public:
     std::vector<Tag *> tags() const;
     Mp4Tag *mp4Tag() const;
     const std::vector<std::unique_ptr<MatroskaTag> > &matroskaTags() const;
+    VorbisComment *vorbisComment() const;
     bool areTagsSupported() const;
 
     // methods to create/remove tags

mp4/mp4container.cpp

@@ -771,7 +771,7 @@ calculatePadding:
         reset();
         try {
             parseTracks();
-        } catch(Failure &) {
+        } catch(const Failure &) {
             addNotification(NotificationType::Critical, "Unable to reparse the header of the new file.", context);
             throw;
         }
@@ -931,11 +931,11 @@ void Mp4Container::updateOffsets(const std::vector<int64> &oldMdatOffsets, const
                         addNotification(NotificationType::Warning, "traf atom stores multiple tfhd atoms but it should only contain exactly one tfhd atom.", context);
                     }
                 }
-            } catch(Failure &) {
+            } catch(const Failure &) {
                 addNotification(NotificationType::Critical, "Unable to parse childs of top-level atom moof.", context);
             }
         }
-    } catch(Failure &) {
+    } catch(const Failure &) {
         addNotification(NotificationType::Critical, "Unable to parse top-level atom moof.", context);
     }
     // update each track
@@ -946,7 +946,7 @@ void Mp4Container::updateOffsets(const std::vector<int64> &oldMdatOffsets, const
         if(!track->isHeaderValid()) {
             try {
                 track->parseHeader();
-            } catch(Failure &) {
+            } catch(const Failure &) {
                 addNotification(NotificationType::Warning, "The chunk offsets of track " + track->name() + " couldn't be updated because the track seems to be invalid..", context);
                 throw;
             }
@@ -954,7 +954,7 @@ void Mp4Container::updateOffsets(const std::vector<int64> &oldMdatOffsets, const
         if(track->isHeaderValid()) {
             try {
                 track->updateChunkOffsets(oldMdatOffsets, newMdatOffsets);
-            } catch(Failure &) {
+            } catch(const Failure &) {
                 addNotification(NotificationType::Warning, "The chunk offsets of track " + track->name() + " couldn't be updated.", context);
                 throw;
             }

mp4/mp4tagfield.cpp

@@ -455,7 +455,7 @@ Mp4TagFieldMaker::Mp4TagFieldMaker(Mp4TagField &field) :
                 // track number and disk number are exceptions
                 // raw data type 0 is used, information is stored as pair of unsigned integers
                 case Mp4TagAtomIds::TrackPosition: case Mp4TagAtomIds::DiskPosition: {
-                    PositionInSet pos = m_field.value().toPositionIntSet();
+                    PositionInSet pos = m_field.value().toPositionInSet();
                     m_writer.writeInt32BE(pos.position());
                     if(pos.total() <= numeric_limits<int16>::max()) {
                         m_writer.writeInt16BE(static_cast<int16>(pos.total()));

ogg/oggcontainer.cpp

@@ -280,12 +280,12 @@ void OggContainer::internalMakeFile()
         }
         // clear iterator
         m_iterator = OggIterator(fileInfo().stream(), startOffset(), fileInfo().size());
-    } catch(OperationAbortedException &) {
+    } catch(const OperationAbortedException &) {
         addNotification(NotificationType::Information, "Rewriting file to apply new tag information has been aborted.", context);
         BackupHelper::restoreOriginalFileFromBackupFile(fileInfo().path(), backupPath, fileInfo().stream(), backupStream);
         m_iterator.setStream(fileInfo().stream());
         throw;
-    } catch(ios_base::failure &ex) {
+    } catch(const ios_base::failure &ex) {
         addNotification(NotificationType::Critical, "IO error occured when rewriting file to apply new tag information.\n" + string(ex.what()), context);
         BackupHelper::restoreOriginalFileFromBackupFile(fileInfo().path(), backupPath, fileInfo().stream(), backupStream);
         m_iterator.setStream(fileInfo().stream());

ogg/oggiterator.h

@@ -39,10 +39,10 @@ public:
     bool bytesRemaining(size_t atLeast) const;
 
     operator bool() const;
-    OggIterator &operator ++();
+    OggIterator &operator++();
-    OggIterator operator ++(int);
+    OggIterator operator++(int);
-    OggIterator &operator --();
+    OggIterator &operator--();
-    OggIterator operator --(int);
+    OggIterator operator--(int);
 
 private:
     bool fetchNextPage();
@@ -256,7 +256,7 @@ inline bool OggIterator::bytesRemaining(size_t atLeast) const
 /*!
  * \brief Increments the current position by one segment if the iterator is valid; otherwise nothing happens.
  */
-inline OggIterator &OggIterator::operator ++()
+inline OggIterator &OggIterator::operator++()
 {
     nextSegment();
     return *this;
@@ -265,7 +265,7 @@ inline OggIterator &OggIterator::operator ++()
 /*!
  * \brief Increments the current position by one segment if the iterator is valid; otherwise nothing happens.
  */
-inline OggIterator OggIterator::operator ++(int)
+inline OggIterator OggIterator::operator++(int)
 {
     OggIterator tmp = *this;
     nextSegment();
@@ -275,7 +275,7 @@ inline OggIterator OggIterator::operator ++(int)
 /*!
  * \brief Decrements the current position by one segment if the iterator is valid; otherwise nothing happens.
  */
-inline OggIterator &OggIterator::operator --()
+inline OggIterator &OggIterator::operator--()
 {
     previousSegment();
     return *this;
@@ -284,7 +284,7 @@ inline OggIterator &OggIterator::operator --()
 /*!
  * \brief Decrements the current position by one segment if the iterator is valid; otherwise nothing happens.
  */
-inline OggIterator OggIterator::operator --(int)
+inline OggIterator OggIterator::operator--(int)
 {
     OggIterator tmp = *this;
     previousSegment();

positioninset.h

@@ -26,6 +26,7 @@ public:
     constexpr int32 position() const;
     constexpr int32 total() const;
     constexpr bool isNull() const;
+    constexpr bool operator==(const PositionInSet &other) const;
 
     template <typename StringType = std::string>
     StringType toString() const;
@@ -91,6 +92,14 @@ constexpr inline bool PositionInSet::isNull() const
     return m_position == 0 && m_total == 0;
 }
 
+/*!
+ * \brief Returns whether this instance equals \a other.
+ */
+constexpr inline bool PositionInSet::operator==(const PositionInSet &other) const
+{
+    return m_position == other.m_position && m_total == other.m_total;
+}
+
 /*!
  * \brief Returns the string representation of the current PositionInSet.
  */

tagvalue.cpp

@@ -9,6 +9,7 @@
 
 #include <algorithm>
 #include <utility>
+#include <cstring>
 
 using namespace std;
 using namespace ConversionUtilities;
@@ -119,7 +120,7 @@ TagValue::TagValue(const PositionInSet &value) :
 TagValue::TagValue(const TagValue &other) :
     m_size(other.m_size),
     m_type(other.m_type),
-    m_dec(other.m_dec),
+    m_desc(other.m_desc),
     m_mimeType(other.m_mimeType),
     m_lng(other.m_lng),
     m_labeledAsReadonly(other.m_labeledAsReadonly),
@@ -140,7 +141,7 @@ TagValue &TagValue::operator=(const TagValue &other)
     if(this != &other) {
         m_size = other.m_size;
         m_type = other.m_type;
-        m_dec = other.m_dec;
+        m_desc = other.m_desc;
         m_mimeType = other.m_mimeType;
         m_lng = other.m_lng;
         m_labeledAsReadonly = other.m_labeledAsReadonly;
@@ -156,6 +157,45 @@ TagValue &TagValue::operator=(const TagValue &other)
     return *this;
 }
 
+/*!
+ * \brief Returns whether both instances are equal.
+ *
+ * Both instances are only considered equal, if the data type, encodings (if relevant for the type) and meta data are equal.
+ */
+bool TagValue::operator==(const TagValue &other) const
+{
+    if(m_type != other.m_type || m_desc != other.m_desc || (!m_desc.empty() && m_descEncoding != other.m_descEncoding)
+            || m_mimeType != other.m_mimeType || m_lng != other.m_lng || m_labeledAsReadonly != other.m_labeledAsReadonly) {
+        return false;
+    }
+    switch(m_type) {
+    case TagDataType::Text:
+        if(m_size != other.m_size && m_encoding != other.m_encoding) {
+            return false;
+        }
+        return strncmp(m_ptr.get(), other.m_ptr.get(), m_size) == 0;
+    case TagDataType::PositionInSet:
+        return toPositionInSet() == other.toPositionInSet();
+    case TagDataType::Integer:
+        return toInteger() == other.toInteger();
+    case TagDataType::StandardGenreIndex:
+        return toStandardGenreIndex() == other.toStandardGenreIndex();
+    case TagDataType::TimeSpan:
+        return toTimeSpan() == other.toTimeSpan();
+    case TagDataType::DateTime:
+        return toDateTime() == other.toDateTime();
+    case TagDataType::Picture:
+    case TagDataType::Binary:
+    case TagDataType::Undefined:
+        if(m_size != other.m_size) {
+            return false;
+        }
+        return strncmp(m_ptr.get(), other.m_ptr.get(), m_size) == 0;
+    default:
+        return false;
+    }
+}
+
 /*!
  * \brief Destroys the TagValue.
  */
@@ -171,7 +211,7 @@ TagValue::~TagValue()
  */
 void TagValue::clearMetadata()
 {
-    m_dec.clear();
+    m_desc.clear();
     m_mimeType.clear();
     m_lng.clear();
     m_labeledAsReadonly = false;
@@ -260,7 +300,7 @@ int TagValue::toStandardGenreIndex() const
  *        PositionInSet representation.
  * \throws Throws ConversionException an failure.
  */
-PositionInSet TagValue::toPositionIntSet() const
+PositionInSet TagValue::toPositionInSet() const
 {
     if(!isEmpty()) {
         switch(m_type) {
@@ -293,7 +333,7 @@ TimeSpan TagValue::toTimeSpan() const
     if(!isEmpty()) {
         switch(m_type) {
         case TagDataType::Text:
-            return TimeSpan::fromSeconds(ConversionUtilities::stringToNumber<int64>(string(m_ptr.get(), m_size)));
+            return TimeSpan::fromString(string(m_ptr.get(), m_size));
         case TagDataType::Integer:
         case TagDataType::TimeSpan:
             switch(m_size) {
@@ -366,7 +406,7 @@ void TagValue::toString(string &result) const
             result = ConversionUtilities::numberToString(toInteger());
             return;
         case TagDataType::PositionInSet:
-            result = toPositionIntSet().toString();
+            result = toPositionInSet().toString();
             return;
         case TagDataType::StandardGenreIndex:
             if(const char *genreName = Id3Genres::stringFromIndex(toInteger())) {
@@ -386,6 +426,56 @@ void TagValue::toString(string &result) const
     result.clear();
 }
 
+/*!
+ * \brief Converts the value of the current TagValue object to its equivalent
+ *        std::wstring representation.
+ * \throws Throws ConversionException on failure.
+ * \remarks Use this only, if UTF-16 text is assigned.
+ */
+u16string TagValue::toWString() const
+{
+    u16string res;
+    toWString(res);
+    return res;
+}
+
+/*!
+ * \brief Converts the value of the current TagValue object to its equivalent
+ *        std::u16string representation.
+ * \throws Throws ConversionException on failure.
+ * \remarks Use this only, if UTF-16 text is assigned.
+ */
+void TagValue::toWString(u16string &result) const
+{
+    if(!isEmpty()) {
+        switch(m_type) {
+        case TagDataType::Text:
+            result.assign(reinterpret_cast<typename u16string::value_type *>(m_ptr.get()), m_size / sizeof(typename u16string::value_type));
+            return;
+        case TagDataType::Integer:
+            result = ConversionUtilities::numberToString<int32, u16string>(toInteger());
+            return;
+        case TagDataType::PositionInSet:
+            result = toPositionInSet().toString<u16string>();
+            return;
+        case TagDataType::StandardGenreIndex:
+            if(const char *genreName = Id3Genres::stringFromIndex(toInteger())) {
+                // TODO: implement this
+                throw ConversionException("Wide default genre strings are currently not supported.");
+            } else {
+                throw ConversionException("No string representation for the assigned standard genre index available.");
+            }
+            break;
+        case TagDataType::TimeSpan:
+            // TODO: implement this
+            throw ConversionException("Wide time span string representations are currently not supported.");
+        default:
+            throw ConversionException("Can not convert binary data/picture to string.");
+        }
+    }
+    result.clear();
+}
+
 /*!
  * \brief Assigns a copy of the given \a text.
  * \param text Specifies the text to be assigned.
@@ -438,15 +528,17 @@ void TagValue::assignStandardGenreIndex(int index)
  */
 void TagValue::assignData(const char *data, size_t length, TagDataType type, TagTextEncoding encoding)
 {
-    m_size = length;
+    if(length > m_size) {
-    m_type = type;
+        m_ptr = make_unique<char[]>(length);
-    m_encoding = encoding;
+    }
-    if(m_size > 0) {
+    if(length) {
-        m_ptr.reset(new char[m_size]);
         std::copy(data, data + length, m_ptr.get());
     } else {
         m_ptr.reset();
     }
+    m_size = length;
+    m_type = type;
+    m_encoding = encoding;
 }
 
 /*!

tagvalue.h

@@ -75,6 +75,7 @@ public:
     // operators
     TagValue &operator=(const TagValue &other);
     TagValue &operator=(TagValue &&other) = default;
+    bool operator==(const TagValue &other) const;
 
     // methods
     bool isEmpty() const;
@@ -84,9 +85,11 @@ public:
     TagDataType type() const;
     std::string toString() const;
     void toString(std::string &result) const;
+    std::u16string toWString() const;
+    void toWString(std::u16string &result) const;
     int32 toInteger() const;
     int toStandardGenreIndex() const;
-    PositionInSet toPositionIntSet() const;
+    PositionInSet toPositionInSet() const;
     ChronoUtilities::TimeSpan toTimeSpan() const;
     ChronoUtilities::DateTime toDateTime() const;
     size_t dataSize() const;
@@ -118,7 +121,7 @@ private:
     std::unique_ptr<char[]> m_ptr;
     std::string::size_type m_size;
     TagDataType m_type;
-    std::string m_dec;
+    std::string m_desc;
     std::string m_mimeType;
     std::string m_lng;
     bool m_labeledAsReadonly;
@@ -212,7 +215,7 @@ inline char *TagValue::dataPointer() const
  */
 inline const std::string &TagValue::description() const
 {
-    return m_dec;
+    return m_desc;
 }
 
 /*!
@@ -225,7 +228,7 @@ inline const std::string &TagValue::description() const
  */
 inline void TagValue::setDescription(const std::string &value, TagTextEncoding encoding)
 {
-    m_dec = value;
+    m_desc = value;
     m_descEncoding = encoding;
 }