static private MidiMetaMessage ParseMidiMetaMessage(MidiFileFormatReader mffr)
{
MidiMetaMessage result = null;
// Get message type
EMetaEventType type = (EMetaEventType)mffr.ReadUInt8();
// Get body length
uint length = mffr.ReadVarLengthQuantity();
switch (type)
{
case EMetaEventType.TrackSequenceNumber:
result = new MidiMetaTrackSequenceNumberMessage(mffr.ReadUInt16());
break;
case EMetaEventType.TextEvent:
case EMetaEventType.Copyright:
case EMetaEventType.SequenceTrackName:
case EMetaEventType.TrackInstrumentName:
case EMetaEventType.Lyric:
case EMetaEventType.Marker:
case EMetaEventType.CuePoint:
case EMetaEventType.ProgramName:
case EMetaEventType.DeviceName:
case EMetaEventType.MidiChannel:
result = new MidiMetaTextMessage(type, mffr.ReadString(length));
break;
case EMetaEventType.MidiPort:
result = new MidiMetaMidiPortMessage(mffr.ReadUInt8());
break;
case EMetaEventType.EndTrack:
// No extra data for the end of track message
result = new MidiMetaMessage(type);
break;
case EMetaEventType.SetTempo:
result = new MidiMetaTempoMessage(mffr.ReadUInt24());
break;
case EMetaEventType.SmpteOffset:
break;
case EMetaEventType.TimeSignature:
result = new MidiMetaTimeSignatureMessage(mffr.ReadUInt8(), mffr.ReadUInt8(), mffr.ReadUInt8(), mffr.ReadUInt8());
break;
case EMetaEventType.KeySignature:
result = new MidiMetaKeySignatureMessage(mffr.ReadUInt8(), (mffr.ReadUInt8() != 0));
break;
case EMetaEventType.SequencerSpecific:
// Read body
byte[] body = new byte[length];
for (int i = 0; i < length; i++)
{
body[i] = mffr.ReadUInt8();
}
result = new MidiMetaMessage(type, body);
break;
default:
throw new FormatException(string.Format("Found unknown or unsupported metaevent code {0}", type));
}
return(result);
}
static private void WriteMidiMetaMessage(MidiFileFormatWriter mffw, MidiMetaMessage message)
{
// Write out message type
mffw.WriteUInt8((byte)message.Type);
// Write out message content
if (message is MidiMetaTrackSequenceNumberMessage)
{
var m = message as MidiMetaTrackSequenceNumberMessage;
mffw.WriteVarLengthQuantity(2);
mffw.WriteUInt16((ushort)m.SequenceNumber);
}
else if (message is MidiMetaTextMessage)
{
var m = message as MidiMetaTextMessage;
mffw.WriteString(m.Text, true);
}
else if (message is MidiMetaMidiPortMessage)
{
var m = message as MidiMetaMidiPortMessage;
mffw.WriteVarLengthQuantity(1);
mffw.WriteUInt8((byte)m.Port);
}
else if (message is MidiMetaTempoMessage)
{
var m = message as MidiMetaTempoMessage;
mffw.WriteVarLengthQuantity(3);
mffw.WriteUInt24(m.Tempo);
}
else if (message is MidiMetaTimeSignatureMessage)
{
var m = message as MidiMetaTimeSignatureMessage;
mffw.WriteVarLengthQuantity(4);
mffw.WriteUInt8((byte)m.Numerator);
mffw.WriteUInt8((byte)m.Denominator);
mffw.WriteUInt8((byte)m.TicksInMetronomeClick);
mffw.WriteUInt8((byte)m.No32ndNotesInQuarterNote);
}
else if (message is MidiMetaKeySignatureMessage)
{
var m = message as MidiMetaKeySignatureMessage;
mffw.WriteVarLengthQuantity(2);
mffw.WriteUInt8((byte)((m.Sharps > 0) ? m.Sharps : -m.Flats));
mffw.WriteUInt8((byte)(m.Minor ? 1 : 0));
}
else if (message.Type == EMetaEventType.SequencerSpecific)
{
mffw.WriteVarLengthQuantity((uint)message.Body.Length);
for (int b = 0; b < message.Body.Length; b++)
{
mffw.WriteUInt8(message.Body[b]);
}
}
else if (message.Type == EMetaEventType.EndTrack)
{
mffw.WriteVarLengthQuantity(0);
}
else
{
throw new FormatException(string.Format("Found event type {0} - not supported!", message.GetType().FullName));
}
}
