private void ReadMidiEvent(Track track, MidiEvent e, byte type, int ptr, out int varlen)
{
byte ctrlMsg = (byte)(type >> 4);
byte channel = (byte)(type & 0xF);
e.midiChannel = channel;
byte note = 0;
byte velocity = 0;
switch (ctrlMsg)
{
// read two bytes
case 8:
note = buffer[ptr + 1];
velocity = buffer[ptr + 2];
sb.AppendFormat("Note Off Channel: {0,2}, Note: {1,3}, Velocity: {2,3}", channel, note, velocity).AppendLine();
varlen = 2;
e.note = note;
e.type = METype.noteoff;
events.Add(e);
break;
case 9:
note = buffer[ptr + 1];
velocity = buffer[ptr + 2];
sb.AppendFormat("Note On Channel: {0,2}, Note: {1,3}, Velocity: {2,3}", channel, note, velocity).AppendLine();
varlen = 2;
e.note = note;
e.velocity = velocity;
events.Add(e);
break;
case 0xA:
note = buffer[ptr + 1];
velocity = buffer[ptr + 2];
sb.AppendFormat("Poly AT Channel: {0,2}, Note: {1,3}, Velocity: {2,3}", channel, note, velocity).AppendLine();
varlen = 2;
break;
case 0xB:
byte ctrlr = buffer[ptr + 1];
byte value = buffer[ptr + 2];
sb.AppendFormat("Control Channel: {0,2}, Note: {1,3}, Velocity: {2,3}", channel, note, velocity).AppendLine();
varlen = 2;
break;
case 0xE:
short pwValue = (short)((buffer[ptr + 1] << 7) + buffer[ptr + 2]);
sb.AppendFormat("Pitch Bd Channel: {0,2}, Value: {1,4}", channel, pwValue).AppendLine();
varlen = 2;
break;
// read one byte
case 0xC:
byte program = buffer[ptr + 1];
sb.AppendFormat("Prog Chg Channel: {0,2}, Program: {1,3}", channel, program).AppendLine();
varlen = 1;
e.type = METype.progchange;
e.program = program;
events.Add(e);
break;
case 0xD:
byte pressure = buffer[ptr + 1];
sb.AppendFormat("Chnl Prs Channel: {0,2}, Pressure: {1,3}", channel, pressure).AppendLine();
varlen = 1;
break;
default:
varlen = 0;
break;
}
}
private int ReadEvents(Track track, int ptr, int length)
{
int offset = 0;
int totalTime = 0;
while (offset < length)
{
// Read the variable-length delta time
int deltatime = ReadVarInt(ptr + offset, out int varlen);
totalTime += deltatime;
MidiEvent ev = new MidiEvent()
{
deltaTime = deltatime,
wait = samplesPerTick * deltatime,
index = totalTime
};
sb.AppendFormat("{0,6} {1,6} {2,6} ", ev.index, ev.deltaTime, ev.wait);
offset += varlen;
byte EventType = buffer[ptr + offset];
if ((EventType & 0x80) == 0)
{
EventType = RunningStatus;
offset--;
}
else
{
RunningStatus = EventType;
}
switch (EventType)
{
case 0xFF:
// Meta
byte metaType = buffer[ptr + offset + 1];
int metaLength = ReadVarInt(ptr + offset + 2, out varlen);
offset += varlen + 2;
// do stuff
ReadMeta(track, metaType, metaLength, ptr + offset);
// prepare to read the next event
offset += metaLength;
break;
case 0xF0:
case 0xF7:
// system exclusive message
int sysexLength = ReadVarInt(ptr + offset + 1, out varlen);
sb.Append("System Exclusive Event: ").Append(EventType).Append(", Length: ").Append(sysexLength).Append(Environment.NewLine);
offset += varlen + 1;
// do stuff
// prepare to read the next event
offset += sysexLength;
break;
default:
// MIDI message
ReadMidiEvent(track, ev, EventType, ptr + offset, out varlen);
offset += varlen + 1;
break;
}
}
return(totalTime);
}
