private static void ReadAudioMetaFields(StreamBuffer sb, MusicMatchTag tag)
{
if (sb == null)
throw new ArgumentNullException("sb");
// Single-line text fields
tag.SongTitle = ReadTextField(sb);
tag.AlbumTitle = ReadTextField(sb);
tag.ArtistName = ReadTextField(sb);
tag.Genre = ReadTextField(sb);
tag.Tempo = ReadTextField(sb);
tag.Mood = ReadTextField(sb);
tag.Situation = ReadTextField(sb);
tag.Preference = ReadTextField(sb);
// Non-text fields
tag.SongDuration = ReadTextField(sb);
tag.CreationDate = DateTime.FromOADate(sb.ReadDouble());
tag.PlayCounter = sb.ReadInt32();
tag.OriginalFilename = ReadTextField(sb);
tag.SerialNumber = ReadTextField(sb);
tag.TrackNumber = sb.ReadInt16();
// Multi-line text fields
tag.Notes = ReadTextField(sb);
tag.ArtistBio = ReadTextField(sb);
tag.Lyrics = ReadTextField(sb);
// Internet addresses
tag.ArtistUrl = ReadTextField(sb);
tag.BuyCdUrl = ReadTextField(sb);
tag.ArtistEmail = ReadTextField(sb);
}
////------------------------------------------------------------------------------------------------------------------------------
/// <inheritdoc/>
public IAudioTagOffset ReadFromStream(Stream stream, TagOrigin tagOrigin)
{
if (stream == null)
throw new ArgumentNullException("stream");
if (!stream.CanRead)
throw new InvalidOperationException("stream can not be read");
if (!stream.CanSeek)
throw new InvalidOperationException("stream can not be seeked");
StreamBuffer sb = stream as StreamBuffer ?? new StreamBuffer(stream);
MusicMatchTag tag = new MusicMatchTag();
// Should we read the header or footer?
MusicMatchHeader headerOrFooter = (tagOrigin == TagOrigin.Start) ? ReadHeader(sb, tagOrigin) : ReadFooter(sb, tagOrigin);
if (headerOrFooter == null)
return null;
long startOffset = 0, endOffset = 0, streamLength = sb.Length;
MusicMatchHeader header = null, footer = null, versionInformation = null;
if (tagOrigin == TagOrigin.Start)
{
header = headerOrFooter;
tag.UseHeader = true;
startOffset = header.Position;
}
else if (tagOrigin == TagOrigin.End)
{
footer = headerOrFooter;
endOffset = Math.Min(footer.Position + MusicMatchTag.FooterSize, streamLength);
// Seek to the Audio metadata offset struct
sb.Position = Math.Max(endOffset - MusicMatchTag.FooterSize - MusicMatchTag.DataOffsetFieldsSize, 0);
// Read the Audio Meta-data Offsets
MusicMatchDataOffsets dataOffsets = ReadDataOffsets(sb);
long startPosition = Math.Max(sb.Position + MusicMatchTag.FooterSize, 0);
foreach (int audioMetaDataOffset in AudioMetaDataSizes.OrderBy(a => a))
{
// Seek to the start of the version information, based on the audioMetaDataOffset
long startPositionHeader = Math.Max(startPosition - audioMetaDataOffset - MusicMatchTag.HeaderSize, 0);
long endPositionHeader = startPositionHeader + HeaderIdentifierBytes.Length;
// Read the version information
versionInformation = ReadHeaderFooter(sb, startPositionHeader, endPositionHeader, HeaderIdentifierBytes, TagOrigin.Start);
if (versionInformation == null)
continue;
startOffset = (versionInformation.Position + MusicMatchTag.HeaderSize) - dataOffsets.TotalDataOffsetsSize;
sb.Position = Math.Max(startOffset - MusicMatchTag.HeaderSize, 0);
header = ReadHeader(sb, TagOrigin.Start);
break;
}
// We've got a problem, Houston.
if (versionInformation == null)
return null;
// Header found? set new startPosition
if (header != null)
{
if (header.Position == versionInformation.Position)
{
header = null;
}
else
{
tag.UseHeader = true;
startOffset = header.Position;
}
}
}
sb.Position = startOffset + (tag.UseHeader ? MusicMatchTag.HeaderSize : 0);
// Read image
tag.Image = MusicMatchImage.ReadFromStream(sb);
// Unused, null padding
byte[] nullPadding = new byte[4];
sb.Read(nullPadding, nullPadding.Length);
// Read version info
if (versionInformation == null)
{
versionInformation = ReadHeader(sb, TagOrigin.Start);
if (versionInformation == null)
{
#if DEBUG
throw new InvalidDataException("Version information not found in the tag.");
#else
return null;
#endif
}
}
else
{
// version information has the same size as the header size.
sb.Position += MusicMatchTag.HeaderSize;
}
if (tag.UseHeader && !versionInformation.Equals(header))
{
#if DEBUG
throw new InvalidDataException("Version information field(s) mismatch the header fields.");
#else
return null;
#endif
}
tag.XingEncoderVersion = versionInformation.XingEncoderVersion;
tag.Version = versionInformation.MusicMatchVersion;
// Read the Audio meta-data
ReadAudioMetaFields(sb, tag);
// Padding
sb.Position += 16;
if (tagOrigin == TagOrigin.Start)
{
long startPosition = sb.Position;
foreach (int audioMetaDataOffset in AudioMetaDataSizes.OrderBy(a => a))
{
//Look for the start of the footer.
long startPositionFooter = Math.Max(startPosition + (audioMetaDataOffset - (sb.Position - startOffset) - (tag.UseHeader ? MusicMatchTag.HeaderSize : 0)), 0);
long endPositionFooter = startPositionFooter + FooterIdentifierBytes.Length;
// Read the footer.
footer = ReadHeaderFooter(sb, startPositionFooter, endPositionFooter, FooterIdentifierBytes, TagOrigin.End);
if (footer != null)
break;
}
// We've got a problem, Houston.
if (footer == null)
return null;
}
return new AudioTagOffset(tagOrigin, startOffset, endOffset, tag);
}
/// <summary>
/// Equals the specified <see cref="MusicMatchTag"/>.
/// </summary>
/// <param name="tag">The <see cref="MusicMatchTag"/>.</param>
/// <returns>true if equal; false otherwise.</returns>
public bool Equals(MusicMatchTag tag)
{
if (ReferenceEquals(null, tag))
return false;
if (ReferenceEquals(this, tag))
return true;
return true;
}
