private int ParseBuffer(byte[] data, int offset, int length, out MidiMessage message)
{
message = null;
int messageLength = 0;
if (length == 0)
{
// Should not happen
return(0);
}
uint rawCommand = data[offset];
uint channel = (rawCommand & 0x0f) + 1;
EMidiCommand command = (EMidiCommand)(rawCommand & 0xF0);
if (command == EMidiCommand.SystemMessageMask)
{
// System message
channel = 0;
command = (EMidiCommand)rawCommand;
messageLength = 1;
switch (command)
{
case EMidiCommand.TimingClock:
message = new TimingClockMessage();
break;
case EMidiCommand.StartSequence:
message = new StartSequenceMessage();
break;
case EMidiCommand.ContinueSequence:
message = new ContinueSequenceMessage();
break;
case EMidiCommand.StopSequence:
message = new StopSequenceMessage();
break;
case EMidiCommand.ActiveSensing:
message = new ActiveSensingMessage();
break;
case EMidiCommand.SystemExclusive:
messageLength = ParseSysex(data, offset, length, ref message);
break;
}
}
else
{
uint p1 = (length >= 2) ? data[offset + 1] : 0u;
uint p2 = (length >= 3) ? data[offset + 2] : 0u;
// Common message
switch (command)
{
case EMidiCommand.NoteOff:
case EMidiCommand.NoteOn:
case EMidiCommand.KeyAfterTouch:
message = new MidiNoteMessage(channel, command, p1, p2);
messageLength = 3;
break;
case EMidiCommand.ControlChange:
message = new MidiControlChangeMessage(channel, p1, p2);
messageLength = 3;
break;
case EMidiCommand.PatchChange:
message = new MidiPatchChangeMessage(channel, p1);
messageLength = 2;
break;
case EMidiCommand.ChannelAfterTouch:
message = new MidiChannelAfterTouchMessage(channel, p1);
messageLength = 2;
break;
case EMidiCommand.PitchWheelChange:
message = new MidiPitchChangeMessage(channel, p1 + (p2 << 7));
messageLength = 3;
break;
}
// Indicate truncated message in reply
if (length < messageLength)
{
messageLength = -1;
}
}
return(messageLength);
}
// Parse a midi message from a midi input MIM_DATA message
private static MidiMessage ParseShortMessage(uint message)
{
MidiMessage result = null;
uint rawCommand = message & 0xff;
uint channel = (rawCommand & 0x0f) + 1;
EMidiCommand command = (EMidiCommand)(rawCommand & 0xF0);
if (command == EMidiCommand.SystemMessageMask)
{
// System message
channel = 0;
command = (EMidiCommand)rawCommand;
switch (command)
{
case EMidiCommand.TimingClock:
result = new TimingClockMessage();
break;
case EMidiCommand.StartSequence:
result = new StartSequenceMessage();
break;
case EMidiCommand.ContinueSequence:
result = new ContinueSequenceMessage();
break;
case EMidiCommand.StopSequence:
result = new StopSequenceMessage();
break;
case EMidiCommand.ActiveSensing:
result = new ActiveSensingMessage();
break;
}
}
else
{
uint p1 = (message >> 8) & 0xff;
uint p2 = (message >> 16) & 0xff;
// Common message
switch (command)
{
case EMidiCommand.NoteOff:
case EMidiCommand.NoteOn:
case EMidiCommand.KeyAfterTouch:
result = new MidiNoteMessage(channel, command, p1, p2);
break;
case EMidiCommand.ControlChange:
result = new MidiControlChangeMessage(channel, p1, p2);
break;
case EMidiCommand.PatchChange:
result = new MidiPatchChangeMessage(channel, p1);
break;
case EMidiCommand.ChannelAfterTouch:
result = new MidiChannelAfterTouchMessage(channel, p1);
break;
case EMidiCommand.PitchWheelChange:
result = new MidiPitchChangeMessage(channel, p1 + (p2 << 7));
break;
}
}
return(result);
}
