public IEnumerable <MidiChunk> Convert(IEnumerable <MidiChunk> chunks)
{
ThrowIfArgument.IsNull(nameof(chunks), chunks);
//
var trackChunks = chunks.OfType <TrackChunk>().ToArray();
if (trackChunks.Length == 1)
{
return(chunks);
}
//
var eventsDescriptors = trackChunks
.SelectMany(trackChunk =>
{
var absoluteTime = 0L;
var channel = -1;
return(trackChunk.Events
.Select(midiEvent =>
{
var channelPrefixEvent = midiEvent as ChannelPrefixEvent;
if (channelPrefixEvent != null)
{
channel = channelPrefixEvent.Channel;
}
if (!(midiEvent is MetaEvent))
{
channel = -1;
}
return new EventDescriptor(midiEvent, (absoluteTime += midiEvent.DeltaTime), channel);
}));
})
.OrderBy(d => d, new EventDescriptorComparer());
//
var resultTrackChunk = new TrackChunk();
var time = 0L;
foreach (var eventDescriptor in eventsDescriptors)
{
MidiEvent midiEvent = eventDescriptor.Event.Clone();
midiEvent.DeltaTime = eventDescriptor.AbsoluteTime - time;
resultTrackChunk.Events.Add(midiEvent);
time = eventDescriptor.AbsoluteTime;
}
//
return(new[] { resultTrackChunk }.Concat(chunks.Where(c => !(c is TrackChunk))));
}
private static ushort?GetSequenceNumber(TrackChunk trackChunk)
{
ThrowIfArgument.IsNull(nameof(trackChunk), trackChunk);
return(trackChunk.Events
.TakeWhile(m => m.DeltaTime == 0)
.OfType <SequenceNumberEvent>()
.FirstOrDefault()
?.Number);
}
/// <summary>
/// Handles finish of track chunk reading. Called after track chunk is read.
/// </summary>
/// <param name="trackChunk">Track chunk read.</param>
/// <remarks>
/// This method called within <see cref="TargetScope.TrackChunk"/> scope.
/// </remarks>
public virtual void OnFinishTrackChunkReading(TrackChunk trackChunk)
{
}
/// <summary>
/// Handles start of track chunk's content reading. Called after track chunk header is read.
/// </summary>
/// <param name="trackChunk">Track chunk is being read.</param>
/// <remarks>
/// This method called within <see cref="TargetScope.TrackChunk"/> scope.
/// </remarks>
public virtual void OnStartTrackChunkContentReading(TrackChunk trackChunk)
{
}
/// <summary>
/// Reads a chunk from a MIDI-file.
/// </summary>
/// <param name="reader">Reader to read a chunk with.</param>
/// <param name="settings">Settings according to which a chunk must be read.</param>
/// <param name="actualTrackChunksCount">Actual count of track chunks at the moment.</param>
/// <param name="expectedTrackChunksCount">Expected count of track chunks.</param>
/// <returns>A MIDI-file chunk.</returns>
/// <exception cref="ObjectDisposedException">Method was called after the reader was disposed.</exception>
/// <exception cref="IOException">An I/O error occurred on the underlying stream.</exception>
/// <exception cref="UnknownChunkException">Chunk to be read has unknown ID and that
/// should be treated as error accordng to the specified <paramref name="settings"/>.</exception>
/// <exception cref="UnexpectedTrackChunksCountException">Actual track chunks
/// count is greater than expected one and that should be treated as error according to
/// the specified <paramref name="settings"/>.</exception>
/// <exception cref="InvalidChunkSizeException">Actual chunk's size differs from the one declared
/// in its header and that should be treated as error according to the specified
/// <paramref name="settings"/>.</exception>
/// <exception cref="UnknownChannelEventException">Reader has encountered an unknown channel event.</exception>
/// <exception cref="NotEnoughBytesException">Value cannot be read since the reader's underlying stream
/// doesn't have enough bytes.</exception>
/// <exception cref="UnexpectedRunningStatusException">Unexpected running status is encountered.</exception>
/// <exception cref="MissedEndOfTrackEventException">Track chunk doesn't end with End Of Track event and that
/// should be treated as error accordng to the specified <paramref name="settings"/>.</exception>
/// <exception cref="InvalidChannelEventParameterValueException">Value of a channel event's parameter
/// just read is invalid.</exception>
/// <exception cref="InvalidMetaEventParameterValueException">Value of a meta event's parameter
/// just read is invalid.</exception>
private static MidiChunk ReadChunk(MidiReader reader, ReadingSettings settings, int actualTrackChunksCount, int?expectedTrackChunksCount)
{
MidiChunk chunk = null;
try
{
var chunkId = reader.ReadString(MidiChunk.IdLength);
if (chunkId.Length < MidiChunk.IdLength)
{
switch (settings.NotEnoughBytesPolicy)
{
case NotEnoughBytesPolicy.Abort:
throw new NotEnoughBytesException("Chunk ID cannot be read since the reader's underlying stream doesn't have enough bytes.",
MidiChunk.IdLength,
chunkId.Length);
case NotEnoughBytesPolicy.Ignore:
return(null);
}
}
//
switch (chunkId)
{
case HeaderChunk.Id:
chunk = new HeaderChunk();
break;
case TrackChunk.Id:
chunk = new TrackChunk();
break;
default:
chunk = TryCreateChunk(chunkId, settings.CustomChunkTypes);
break;
}
//
if (chunk == null)
{
switch (settings.UnknownChunkIdPolicy)
{
case UnknownChunkIdPolicy.ReadAsUnknownChunk:
chunk = new UnknownChunk(chunkId);
break;
case UnknownChunkIdPolicy.Skip:
var size = reader.ReadDword();
reader.Position += size;
return(null);
case UnknownChunkIdPolicy.Abort:
throw new UnknownChunkException($"'{chunkId}' chunk ID is unknown.", chunkId);
}
}
//
if (chunk is TrackChunk && expectedTrackChunksCount != null && actualTrackChunksCount >= expectedTrackChunksCount)
{
ReactOnUnexpectedTrackChunksCount(settings.UnexpectedTrackChunksCountPolicy, actualTrackChunksCount, expectedTrackChunksCount.Value);
switch (settings.ExtraTrackChunkPolicy)
{
case ExtraTrackChunkPolicy.Read:
break;
case ExtraTrackChunkPolicy.Skip:
var size = reader.ReadDword();
reader.Position += size;
return(null);
}
}
//
chunk.Read(reader, settings);
}
catch (NotEnoughBytesException ex)
{
ReactOnNotEnoughBytes(settings.NotEnoughBytesPolicy, ex);
}
catch (EndOfStreamException ex)
{
ReactOnNotEnoughBytes(settings.NotEnoughBytesPolicy, ex);
}
return(chunk);
}
/// <summary>
/// Gets all channel numbers presented in the specified <see cref="TrackChunk"/>.
/// </summary>
/// <param name="trackChunk"><see cref="TrackChunk"/> to get channels of.</param>
/// <returns>Collection of channel numbers presented in the <paramref name="trackChunk"/>.</returns>
/// <exception cref="ArgumentNullException"><paramref name="trackChunk"/> is <c>null</c>.</exception>
public static IEnumerable <FourBitNumber> GetChannels(this TrackChunk trackChunk)
{
ThrowIfArgument.IsNull(nameof(trackChunk), trackChunk);
return(trackChunk.Events.OfType <ChannelEvent>().Select(e => e.Channel).Distinct().ToArray());
}
/// <summary>
/// Splits a track chunk into multiple ones that correspond to <see cref="MidiFileFormat.MultiTrack"/>.
/// </summary>
/// <param name="trackChunk">Track chunk to split into multiple ones.</param>
/// <returns>Multiple track chunks that represent <paramref name="trackChunk"/>.</returns>
/// <remarks>
/// Note that events will be cloned so events in the result track chunks will not be equal
/// by reference to events in the <paramref name="trackChunk"/>.
/// </remarks>
/// <exception cref="ArgumentNullException"><paramref name="trackChunk"/> is <c>null</c>.</exception>
public static IEnumerable <TrackChunk> Explode(this TrackChunk trackChunk)
{
ThrowIfArgument.IsNull(nameof(trackChunk), trackChunk);
return(ConvertTrackChunks(new[] { trackChunk }, MidiFileFormat.MultiTrack));
}
