Sequencer: start()
/*
* Copyright (c) 2004 David Flanagan. All rights reserved.
* This code is from the book Java Examples in a Nutshell, 3nd Edition.
* It is provided AS-IS, WITHOUT ANY WARRANTY either expressed or implied.
* You may study, use, and modify it for any non-commercial purpose,
* including teaching and use in open-source projects.
* You may distribute it non-commercially as long as you retain this notice.
* For a commercial use license, or to purchase the book,
* please visit http://www.davidflanagan.com/javaexamples3.
*/
import java.io.File;
import java.io.IOException;
import javax.sound.midi.InvalidMidiDataException;
import javax.sound.midi.MetaEventListener;
import javax.sound.midi.MetaMessage;
import javax.sound.midi.MidiEvent;
import javax.sound.midi.MidiSystem;
import javax.sound.midi.MidiUnavailableException;
import javax.sound.midi.Sequence;
import javax.sound.midi.Sequencer;
import javax.sound.midi.ShortMessage;
import javax.sound.midi.Synthesizer;
import javax.sound.midi.Track;
public class Main {
// These are some MIDI constants from the spec. They aren't defined
// for us in javax.sound.midi.
public static final int DAMPER_PEDAL = 64;
public static final int DAMPER_ON = 127;
public static final int DAMPER_OFF = 0;
public static final int END_OF_TRACK = 47;
public static void main(String[] args) throws MidiUnavailableException, InvalidMidiDataException,
IOException {
int instrument = 0;
int tempo = 120;
String filename = null;
// Parse the options
// -i <instrument number> default 0, a piano. Allowed values: 0-127
// -t <beats per minute> default tempo is 120 quarter notes per minute
// -o <filename> save to a midi file instead of playing
int a = 0;
while (a < args.length) {
if (args[a].equals("-i")) {
instrument = Integer.parseInt(args[a + 1]);
a += 2;
} else if (args[a].equals("-t")) {
tempo = Integer.parseInt(args[a + 1]);
a += 2;
} else if (args[a].equals("-o")) {
filename = args[a + 1];
a += 2;
} else
break;
}
char[] notes = args[a].toCharArray();
// 16 ticks per quarter note.
Sequence sequence = new Sequence(Sequence.PPQ, 16);
// Add the specified notes to the track
addTrack(sequence, instrument, tempo, notes);
if (filename == null) { // no filename, so play the notes
// Set up the Sequencer and Synthesizer objects
Sequencer sequencer = MidiSystem.getSequencer();
sequencer.open();
Synthesizer synthesizer = MidiSystem.getSynthesizer();
synthesizer.open();
sequencer.getTransmitter().setReceiver(synthesizer.getReceiver());
// Specify the sequence to play, and the tempo to play it at
sequencer.setSequence(sequence);
sequencer.setTempoInBPM(tempo);
// Let us know when it is done playing
sequencer.addMetaEventListener(new MetaEventListener() {
public void meta(MetaMessage m) {
// A message of this type is automatically sent
// when we reach the end of the track
if (m.getType() == END_OF_TRACK)
System.exit(0);
}
});
// And start playing now.
sequencer.start();
} else { // A file name was specified, so save the notes
int[] allowedTypes = MidiSystem.getMidiFileTypes(sequence);
if (allowedTypes.length == 0) {
System.err.println("No supported MIDI file types.");
} else {
MidiSystem.write(sequence, allowedTypes[0], new File(filename));
System.exit(0);
}
}
}
static final int[] offsets = { // add these amounts to the base value
// A B C D E F G
-4, -2, 0, 1, 3, 5, 7 };
/*
* This method parses the specified char[] of notes into a Track. The musical
* notation is the following: A-G: A named note; Add b for flat and # for
* sharp. +: Move up one octave. Persists. -: Move down one octave. Persists.
* /1: Notes are whole notes. Persists 'till changed /2: Half notes /4:
* Quarter notes /n: N can also be, 8, 16, 32, 64. s: Toggle sustain pedal on
* or off (initially off)
* >: Louder. Persists <: Softer. Persists .: Rest. Length depends on current
* length setting Space: Play the previous note or notes; notes not separated
* by spaces are played at the same time
*/
public static void addTrack(Sequence s, int instrument, int tempo, char[] notes)
throws InvalidMidiDataException {
Track track = s.createTrack(); // Begin with a new track
// Set the instrument on channel 0
ShortMessage sm = new ShortMessage();
sm.setMessage(ShortMessage.PROGRAM_CHANGE, 0, instrument, 0);
track.add(new MidiEvent(sm, 0));
int n = 0; // current character in notes[] array
int t = 0; // time in ticks for the composition
// These values persist and apply to all notes 'till changed
int notelength = 16; // default to quarter notes
int velocity = 64; // default to middle volume
int basekey = 60; // 60 is middle C. Adjusted up and down by octave
boolean sustain = false; // is the sustain pedal depressed?
int numnotes = 0; // How many notes in current chord?
while (n < notes.length) {
char c = notes[n++];
if (c == '+')
basekey += 12; // increase octave
else if (c == '-')
basekey -= 12; // decrease octave
else if (c == '>')
velocity += 16; // increase volume;
else if (c == '<')
velocity -= 16; // decrease volume;
else if (c == '/') {
char d = notes[n++];
if (d == '2')
notelength = 32; // half note
else if (d == '4')
notelength = 16; // quarter note
else if (d == '8')
notelength = 8; // eighth note
else if (d == '3' && notes[n++] == '2')
notelength = 2;
else if (d == '6' && notes[n++] == '4')
notelength = 1;
else if (d == '1') {
if (n < notes.length && notes[n] == '6')
notelength = 4; // 1/16th note
else
notelength = 64; // whole note
}
} else if (c == 's') {
sustain = !sustain;
// Change the sustain setting for channel 0
ShortMessage m = new ShortMessage();
m
.setMessage(ShortMessage.CONTROL_CHANGE, 0, DAMPER_PEDAL, sustain ? DAMPER_ON
: DAMPER_OFF);
track.add(new MidiEvent(m, t));
} else if (c >= 'A' && c <= 'G') {
int key = basekey + offsets[c - 'A'];
if (n < notes.length) {
if (notes[n] == 'b') { // flat
key--;
n++;
} else if (notes[n] == '#') { // sharp
key++;
n++;
}
}
addNote(track, t, notelength, key, velocity);
numnotes++;
} else if (c == ' ') {
// Spaces separate groups of notes played at the same time.
// But we ignore them unless they follow a note or notes.
if (numnotes > 0) {
t += notelength;
numnotes = 0;
}
} else if (c == '.') {
// Rests are like spaces in that they force any previous
// note to be output (since they are never part of chords)
if (numnotes > 0) {
t += notelength;
numnotes = 0;
}
// Now add additional rest time
t += notelength;
}
}
}
// A convenience method to add a note to the track on channel 0
public static void addNote(Track track, int startTick, int tickLength, int key, int velocity)
throws InvalidMidiDataException {
ShortMessage on = new ShortMessage();
on.setMessage(ShortMessage.NOTE_ON, 0, key, velocity);
ShortMessage off = new ShortMessage();
off.setMessage(ShortMessage.NOTE_OFF, 0, key, velocity);
track.add(new MidiEvent(on, startTick));
track.add(new MidiEvent(off, startTick + tickLength));
}
}
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