/// <summary>Parse a meta MIDI event from the data stream.</summary>
/// <param name="deltaTime">The previously parsed delta-time for this event.</param>
/// <param name="eventType">The previously parsed type of message we're expecting to find.</param>
/// <param name="data">The data stream from which to read the event information.</param>
/// <param name="pos">The position of the start of the event information.</param>
/// <returns>The parsed meta MIDI event.</returns>
private static MidiEvent ParseMetaEvent(long deltaTime, byte eventType, byte [] data, ref long pos)
{
try
{
MidiEvent tempEvent = null;
// Create the correct meta event based on its meta event id/type
switch (eventType)
{
// Sequence number
case 0x00:
pos++; // skip past the 0x02
int number = ((data[pos] << 8) | data[pos + 1]);
tempEvent = new SequenceNumber(deltaTime, number);
pos += 2; // skip read values
break;
// Text events (copyright, lyrics, etc)
case 0x01: tempEvent = new Text(deltaTime, ReadASCIIText(data, ref pos)); break;
case 0x02: tempEvent = new Copyright(deltaTime, ReadASCIIText(data, ref pos)); break;
case 0x03: tempEvent = new SequenceTrackName(deltaTime, ReadASCIIText(data, ref pos)); break;
case 0x04: tempEvent = new Instrument(deltaTime, ReadASCIIText(data, ref pos)); break;
case 0x05: tempEvent = new Lyric(deltaTime, ReadASCIIText(data, ref pos)); break;
case 0x06: tempEvent = new Marker(deltaTime, ReadASCIIText(data, ref pos)); break;
case 0x07: tempEvent = new CuePoint(deltaTime, ReadASCIIText(data, ref pos)); break;
case 0x08: tempEvent = new ProgramName(deltaTime, ReadASCIIText(data, ref pos)); break;
case 0x09: tempEvent = new DeviceName(deltaTime, ReadASCIIText(data, ref pos)); break;
// Channel prefix
case 0x20:
pos++; // skip 0x1
tempEvent = new ChannelPrefix(deltaTime, data[pos]);
pos++; // skip read value
break;
// Port number
case 0x21:
pos++; // skip 0x1
tempEvent = new MidiPort(deltaTime, data[pos]);
pos++; // skip read value
break;
// End of track
case 0x2F:
pos++; // skip 0x0
tempEvent = new EndOfTrack(deltaTime);
break;
// Tempo
case 0x51:
pos++; // skip 0x3
int tempo = ((data[pos] << 16) | data[pos + 1] << 8 | data[pos + 2]);
tempEvent = new Tempo(deltaTime, tempo);
pos += 3;
break;
// SMPTE offset
case 0x54:
pos++; // skip 0x5
tempEvent = new SMPTEOffset(deltaTime,
data[pos], data[pos + 1], data[pos + 2], data[pos + 3], data[pos + 4]);
pos += 5;
break;
// Time signature
case 0x58:
pos++; // skip past 0x4
tempEvent = new TimeSignature(deltaTime,
data[pos], data[pos + 1], data[pos + 2], data[pos + 3]);
pos += 4;
break;
// Key signature
case 0x59:
pos++; // skip past 0x2
tempEvent = new KeySignature(deltaTime, (Key)data[pos], (Tonality)data[pos + 1]);
pos += 2;
break;
// Proprietary
case 0x7F:
// Read in the variable length and that much data, then store it
long length = ReadVariableLength(data, ref pos);
byte [] propData = new byte[length];
Array.Copy(data, (int)pos, propData, 0, (int)length);
tempEvent = new Proprietary(deltaTime, propData);
pos += length;
break;
// An unknown meta event!
default:
// Read in the variable length and that much data, then store it
length = ReadVariableLength(data, ref pos);
byte [] unknownData = new byte[length];
Array.Copy(data, (int)pos, unknownData, 0, (int)length);
tempEvent = new UnknownMetaMidiEvent(deltaTime, eventType, unknownData);
pos += length;
break;
}
return(tempEvent);
}
// Something bad happened; wrap it in a parser exception
catch (Exception exc) { throw new MidiParserException("Unable to parse meta MIDI event.", exc, pos); }
}
/// <summary>Creates an object creation expression for an event.</summary>
/// <param name="ev">The event to create.</param>
/// <returns>The object creation expression for the event.</returns>
private static CodeObjectCreateExpression CreateMetaEvent(MidiEvent ev)
{
CodeObjectCreateExpression newEvent = null;
CodeExpression delta = new CodePrimitiveExpression(ev.DeltaTime);
// SEQUENCE NUMBER
if (ev is SequenceNumber)
{
SequenceNumber midiEvent = (SequenceNumber)ev;
newEvent = new CodeObjectCreateExpression(
typeof(SequenceNumber),
new CodeExpression[] {
delta,
new CodePrimitiveExpression(midiEvent.Number)
});
}
// TEXT
else if (ev is Text)
{
Text midiEvent = (Text)ev;
newEvent = new CodeObjectCreateExpression(
typeof(Text),
new CodeExpression[] {
delta,
new CodePrimitiveExpression(midiEvent.Text)
});
}
// Copyright
else if (ev is Copyright)
{
Copyright midiEvent = (Copyright)ev;
newEvent = new CodeObjectCreateExpression(
typeof(Copyright),
new CodeExpression[] {
delta,
new CodePrimitiveExpression(midiEvent.Text)
});
}
// SEQUENCE TRACK NAME
else if (ev is SequenceTrackName)
{
SequenceTrackName midiEvent = (SequenceTrackName)ev;
newEvent = new CodeObjectCreateExpression(
typeof(SequenceTrackName),
new CodeExpression[] {
delta,
new CodePrimitiveExpression(midiEvent.Text)
});
}
// INSTRUMENT
else if (ev is Instrument)
{
Instrument midiEvent = (Instrument)ev;
newEvent = new CodeObjectCreateExpression(
typeof(Instrument),
new CodeExpression[] {
delta,
new CodePrimitiveExpression(midiEvent.Text)
});
}
// Lyric
else if (ev is Lyric)
{
Lyric midiEvent = (Lyric)ev;
newEvent = new CodeObjectCreateExpression(
typeof(Lyric),
new CodeExpression[] {
delta,
new CodePrimitiveExpression(midiEvent.Text)
});
}
// Marker
else if (ev is Marker)
{
Marker midiEvent = (Marker)ev;
newEvent = new CodeObjectCreateExpression(
typeof(Marker),
new CodeExpression[] {
delta,
new CodePrimitiveExpression(midiEvent.Text)
});
}
// CuePoint
else if (ev is CuePoint)
{
CuePoint midiEvent = (CuePoint)ev;
newEvent = new CodeObjectCreateExpression(
typeof(CuePoint),
new CodeExpression[] {
delta,
new CodePrimitiveExpression(midiEvent.Text)
});
}
// ProgramName
else if (ev is ProgramName)
{
ProgramName midiEvent = (ProgramName)ev;
newEvent = new CodeObjectCreateExpression(
typeof(ProgramName),
new CodeExpression[] {
delta,
new CodePrimitiveExpression(midiEvent.Text)
});
}
// ProgramName
else if (ev is DeviceName)
{
DeviceName midiEvent = (DeviceName)ev;
newEvent = new CodeObjectCreateExpression(
typeof(DeviceName),
new CodeExpression[] {
delta,
new CodePrimitiveExpression(midiEvent.Text)
});
}
// ChannelPrefix
else if (ev is ChannelPrefix)
{
ChannelPrefix midiEvent = (ChannelPrefix)ev;
newEvent = new CodeObjectCreateExpression(
typeof(ChannelPrefix),
new CodeExpression[] {
delta,
new CodePrimitiveExpression(midiEvent.Prefix)
});
}
// MidiPort
else if (ev is MidiPort)
{
MidiPort midiEvent = (MidiPort)ev;
newEvent = new CodeObjectCreateExpression(
typeof(MidiPort),
new CodeExpression[] {
delta,
new CodePrimitiveExpression(midiEvent.Port)
});
}
// EndOfTrack
else if (ev is EndOfTrack)
{
EndOfTrack midiEvent = (EndOfTrack)ev;
newEvent = new CodeObjectCreateExpression(
typeof(EndOfTrack),
new CodeExpression[] {
delta
});
}
// Tempo
else if (ev is Tempo)
{
Tempo midiEvent = (Tempo)ev;
newEvent = new CodeObjectCreateExpression(
typeof(Tempo),
new CodeExpression[] {
delta,
new CodePrimitiveExpression(midiEvent.Value)
});
}
// SMPTEOffset
else if (ev is SMPTEOffset)
{
SMPTEOffset midiEvent = (SMPTEOffset)ev;
newEvent = new CodeObjectCreateExpression(
typeof(SMPTEOffset),
new CodeExpression[] {
delta,
new CodePrimitiveExpression(midiEvent.Hours),
new CodePrimitiveExpression(midiEvent.Minutes),
new CodePrimitiveExpression(midiEvent.Seconds),
new CodePrimitiveExpression(midiEvent.Frames),
new CodePrimitiveExpression(midiEvent.FractionalFrames)
});
}
// TimeSignature
else if (ev is TimeSignature)
{
TimeSignature midiEvent = (TimeSignature)ev;
newEvent = new CodeObjectCreateExpression(
typeof(TimeSignature),
new CodeExpression[] {
delta,
new CodePrimitiveExpression(midiEvent.Numerator),
new CodePrimitiveExpression(midiEvent.Denominator),
new CodePrimitiveExpression(midiEvent.MidiClocksPerClick),
new CodePrimitiveExpression(midiEvent.NumberOfNotated32nds)
});
}
// KeySignature
else if (ev is KeySignature)
{
KeySignature midiEvent = (KeySignature)ev;
newEvent = new CodeObjectCreateExpression(
typeof(KeySignature),
new CodeExpression[] {
delta,
new CodeCastExpression(typeof(Key), new CodePrimitiveExpression((byte)midiEvent.Key)),
new CodeCastExpression(typeof(Tonality), new CodePrimitiveExpression((byte)midiEvent.Tonality))
});
}
// Proprietary
else if (ev is Proprietary)
{
Proprietary midiEvent = (Proprietary)ev;
newEvent = new CodeObjectCreateExpression(
typeof(Proprietary),
new CodeExpression[] {
delta,
CreateDataArray(midiEvent.Data)
});
}
// UnknownMetaMidiEvent
else if (ev is UnknownMetaMidiEvent)
{
UnknownMetaMidiEvent midiEvent = (UnknownMetaMidiEvent)ev;
newEvent = new CodeObjectCreateExpression(
typeof(UnknownMetaMidiEvent),
new CodeExpression[] {
delta,
new CodePrimitiveExpression(midiEvent.MetaEventID),
CreateDataArray(midiEvent.Data)
});
}
// Return the event
return(newEvent);
}
