/**
* Read from a standard MIDI file
*
* @params InputStream - the datasource to read from
* @params Score score - the score to place jMusic data translation into
* @exception IOException - any IO problems
*/
public void read(InputStream is) throws IOException {
// Given the small size of MIDI files read all
// data into a ByteArrayStream for further processing
byte[] fileData = new byte[is.available()];
is.read(fileData);
ByteArrayInputStream bais = new ByteArrayInputStream(fileData);
DataInputStream dis = new DataInputStream(bais);
// clear any SMF data
if (!this.trackList.isEmpty()) {
this.trackList.removeAllElements(); // remove any previous tracks
}
// check header for MIDIfile validity
if (dis.readInt() != 0x4D546864) { // Check for MIDI track validity
throw new IOException("This is NOT a MIDI file !!!");
} else { // If MIDI file passes skip length bytes
dis.readInt(); // skip over Length info
}
// get SMF Class data
try {
fileType = dis.readShort();
if (VERBOSE) System.out.println("MIDI file type = " + fileType);
this.numOfTracks = dis.readShort();
if (VERBOSE) System.out.println("Number of tracks = " + numOfTracks);
this.ppqn = dis.readShort();
if (VERBOSE) System.out.println("ppqn = " + ppqn);
} catch (IOException e) {
System.out.println(e);
e.printStackTrace();
}
// skip the tempo track fro type 1 files
/*
if(fileType == 1) {
skipATrack(dis);
numOfTracks--;
}
*/
// Read all track chunks
for (int i = 0; i < numOfTracks; i++) {
readTrackChunk(dis);
}
is.close();
dis.close();
}
/**
* Reads a MIDI track chunk
*
* @param DataInputStream dis - the input stream to read from
* @exception IOException
*/
private void readTrackChunk(DataInputStream dis) throws IOException {
// local variables for Track class
Track track = new Track();
// Insert new Track into a list of tracks
this.trackList.addElement(track);
int deltaTime = 0;
if (VERBOSE) System.out.println("Reading Track ..........");
// Read track header
if (dis.readInt() != 0x4D54726B) { // If MTrk read is wrong
throw new IOException("Track started in wrong place!!!! ABORTING");
} else { // If MTrk read ok get bytesRemaining
dis.readInt();
}
// loop variables
int status, oldStatus = 0, eventLength = 0;
// Start gathering event data
Event event = null;
while (true) {
try {
// get variable length timestamp
deltaTime = MidiUtil.readVarLength(dis);
// mark stream so we can return if we need running status
dis.mark(2);
status = dis.readUnsignedByte();
// decide on running status
if (status < 0x80) { // set running status
status = oldStatus;
// return stream to before status read
dis.reset();
}
// create default event of correct type
if (status >= 0xFF) { // Meta Event
int type = dis.readUnsignedByte();
eventLength = MidiUtil.readVarLength(dis);
event = MidiUtil.createMetaEvent(type);
} else if (status >= 0xF0) { // System Exclusive --- NOT SUPPORTED
System.out.println("SysEX---");
eventLength = MidiUtil.readVarLength(dis);
} else if (status >= 0x80) { // MIDI voice event
short selection = (short) (status / 0x10);
short midiChannel = (short) (status - (selection * 0x10));
VoiceEvt evt = (VoiceEvt) MidiUtil.createVoiceEvent(selection);
evt.setMidiChannel(midiChannel);
event = evt;
if (event == null) {
throw new IOException("MIDI file read error: invalid voice event type!");
}
}
oldStatus = status;
} catch (Exception e) {
e.printStackTrace();
System.exit(1);
}
if (event != null) {
// read data into the new event and
// add the new event to the Track object
event.setTime(deltaTime);
event.read(dis);
// if (VERBOSE) event.print();
track.addEvent(event);
// event.print();
if (event instanceof EndTrack) break;
} else {
// skip the stream ahead to next valid event
dis.skipBytes(eventLength);
}
}
}
