//- static methods ------------------------------------------------------------
public static Message getMessage(byte[] data)
{
Message msg = null;
int status = data[0];
if (status < 0xF0) //midi channel message
{
int msgtype = status / 16;
int channel = status % 16;
int b1 = data[1];
int b2 = 0;
if ((msgtype != 0xC) && (msgtype != 0xD))
{
b2 = data[2];
}
msg = Message.getChannelMessage(msgtype, channel, b1, b2);
}
else if (status == 0xF0) //sys ex msg
{
List <byte> bytes = new List <byte>(data);
msg = new SysExMessage(bytes);
}
else
{ //status msg
int b1 = 0;
int b2 = 0;
int datalen = SystemMessage.SysMsgLen[status - 0xF0] - 1;
if (datalen > 0)
{
b1 = data[1];
}
if (datalen > 1)
{
b2 = data[2];
b1 = ((b1 % 128) * 128) + (b2 % 128);
}
msg = new SystemMessage(status, b1);
}
return(msg);
}
//read data from a single track chunk
private static void loadTrackData(MidiInStream stream, Sequence seq, int trackNum)
{
//read track header
String trackSig = stream.getString(4);
uint trackDataLength = stream.getFour();
if (!trackSig.Equals("MTrk"))
{
throw new MidiFileException(stream.filename + " has an invalid track at ", stream.getDataPos() - 8);
}
Track track = seq.addTrack(); //get new track from sequence
track.setName("Track " + trackNum.ToString());
int currentTime = 0; //event time in ticks
runningStatus = 0;
sysexCont = false;
prevSysEx = null;
Event evt = null;
int startpos = stream.getDataPos();
while ((stream.getDataPos() - startpos) < trackDataLength)
{
currentTime += (int)stream.getVariableLengthVal(); //add delta time to current num of ticks
evt = loadEventData(stream);
if ((evt != null) && !(evt is EndofTrackEvent ||
evt is MarkerEvent || evt is CuePointEvent || //these are ignored in tracks other than track 0
evt is TempoEvent || evt is SMPTEOffsetEvent ||
evt is TimeSignatureEvent || evt is KeySignatureEvent))
{
track.addEvent(evt, currentTime);
}
}
//last event in track must be an "end of track" event
if ((evt != null) && !(evt is EndofTrackEvent))
{
throw new MidiFileException(stream.filename + ": track " + curTrackNum.ToString() +
"missing end of track event at ", stream.getDataPos() - 8);
}
}
//build the tempo, meter and marker maps from tempo message from track 0
private static void loadTrackZeroData(MidiInStream stream, Sequence seq)
{
//read track header
String trackSig = stream.getString(4);
uint trackDataLength = stream.getFour();
if (!trackSig.Equals("MTrk"))
{
throw new MidiFileException(stream.filename + " has an invalid track 0 at ", stream.getDataPos() - 8);
}
int currentTime = 0; //event time in ticks
runningStatus = 0;
sysexCont = false;
prevSysEx = null;
Event evt;
Meter prevMeter = null;
int startpos = stream.getDataPos();
while ((stream.getDataPos() - startpos) < trackDataLength)
{
currentTime += (int)stream.getVariableLengthVal(); //add delta time to current num of ticks
evt = loadEventData(stream);
if (evt is TempoEvent)
{
Tempo tempo = new Tempo(currentTime, ((TempoEvent)evt).tempo);
seq.tempoMap.addTempo(tempo);
}
else if (evt is SMPTEOffsetEvent) //not handling smpte timing yet
{
}
else if (evt is TimeSignatureEvent)
{
int keysig = (prevMeter != null) ? prevMeter.keysig : 0;
Meter meter = new Meter(currentTime, ((TimeSignatureEvent)evt).numer, ((TimeSignatureEvent)evt).denom, keysig);
seq.meterMap.addMeter(meter);
prevMeter = meter;
}
else if (evt is KeySignatureEvent)
{
int numer = 4;
int denom = 4;
if (prevMeter != null)
{
numer = prevMeter.numer;
denom = prevMeter.denom;
}
Meter meter = new Meter(currentTime, numer, denom, ((KeySignatureEvent)evt).keySig);
seq.meterMap.addMeter(meter);
prevMeter = meter;
}
else if (evt is MarkerEvent)
{
}
else if (evt is CuePointEvent)
{
}
}
}
//read data for a midi message (80 - ff), handle sysex continuation and escape sequences
private static Message loadMessageData(MidiInStream stream, int status)
{
Message msg = null;
if (status < 0xF0) //midi channel message
{
int msgtype = status / 16;
int channel = status % 16;
int b1 = stream.getOne();
int b2 = 0;
if ((msgtype != 0xC) && (msgtype != 0xD))
{
b2 = stream.getOne();
}
msg = Message.getChannelMessage(msgtype, channel, b1, b2);
}
else if (status == 0xF0) //sysex message
{
int len = stream.getOne();
List <byte> sysExData = stream.getRange(len);
sysexCont = (sysExData[sysExData.Count - 1] != 0xf7); //is the last byte of sysex data a F7?
msg = new SysExMessage(sysExData);
prevSysEx = (SysExMessage)msg;
runningStatus = 0; //sysex msg cancel running status
}
else if (status == 0xF7)
{
if (sysexCont) //sysex continuation - append this data to prev sysex message
{
int len = stream.getOne();
List <byte> contData = stream.getRange(len);
sysexCont = (contData[contData.Count - 1] != 0xf7); //is the last byte of sysex data a F7?
prevSysEx.sysExData.AddRange(contData);
}
else
{ //escape sequence
int len = stream.getOne();
List <byte> escData = stream.getRange(len);
msg = new EscapeMessage(escData);
}
runningStatus = 0;
}
else
{ //system common msgs shouldn't occur here, but if they do, we need to skip them
int b1 = 0;
int b2 = 0;
int datalen = SystemMessage.SysMsgLen[status - 0xF0] - 1;
if (datalen > 0)
{
b1 = stream.getOne();
}
if (datalen > 1)
{
b2 = stream.getOne();
b1 = ((b1 % 128) * 128) + (b2 % 128);
}
msg = new SystemMessage(status, b1);
runningStatus = 0;
}
return(msg);
}
