Simple Midi Problem

[P Katergiathis]

... from a Java newbie, fluent in other languages.

I am trying to create a simple program that will open a midi out port on my computer and send a note to it. My computer is running Windows and i run the following code in order to find out the available midi ports on my machine:

import java.util.*;
import javax.sound.midi.*;
 
class MidiTest
{
   public static void main(String[] args) {
   System.out.println("\n");
   MidiDevice.Info[] devices = MidiSystem.getMidiDeviceInfo();
for (MidiDevice.Info deviceInfo : devices) {
   System.out.println("Device Name : " + deviceInfo.getName());
   System.out.println("Device Description : " + deviceInfo.getDescription() + "\n");
}
}
}

The code reveals the following information:

Device Name : LoopBe Internal MIDI
Device Description : No details available
 
Device Name : Microsoft MIDI Mapper
Device Description : Windows MIDI_MAPPER
 
Device Name : Microsoft GS Wavetable Synth
Device Description : Internal software synthesizer
 
Device Name : LoopBe Internal MIDI
Device Description : External MIDI Port
 
Device Name : Real Time Sequencer
Device Description : Software sequencer
 
Device Name : Java Sound Synthesizer
Device Description : Software wavetable synthesizer and receiver

... so , all i want to do is select any of these ports and send a C to it for a given time duration.

Any help is welcome.

Best Regards

[Ulf Dittmer]

Welcome to JavaRanch.

I think the you need to create several objects, first a Sequencer, then a Track, then a MidiEvent, and finally a MidiMessage with the appropriate data. It looks like you need to know the MIDI file format for this.

An example -which doesn't actually look all that complicated- can be found here.

[P Katergiathis]

Thank you for replying.
I am aware of the technique that you described (and the related example), yet it is not what i want, because it sends a note to a "synthesizer", namely the default windows synth of my on-board card.

What i need is a way to send a midi message (a midi event, actually) to a pre-defined "receiver", in order to drive (via midi) an external synth.

Take this code for example:

package com.wickedcooljava.media;
 
import javax.sound.midi.MidiDevice;
import javax.sound.midi.MidiMessage;
import javax.sound.midi.MidiSystem;
import javax.sound.midi.MidiUnavailableException;
import javax.sound.midi.Receiver;
 
/*
Example code from Wicked Cool Java (No Starch Press)
Copyright (C) 2005 Brian D. Eubanks
 
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
 
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.
 
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 
Note: The LGPL licence can be found online at <a href="http://www.gnu.org" target="_blank" rel="nofollow">http://www.gnu.org</a>
 
*/
/**
 * Example sending output to a MIDI device.
 */
public class MidiOutputExample {
 
public static void main(String[] args) {
try {
MidiDevice.Info[] devices = MidiSystem.getMidiDeviceInfo();
for (MidiDevice.Info deviceInfo : devices) {
System.out.println(deviceInfo.getDescription());
MidiDevice device = MidiSystem.getMidiDevice(deviceInfo);
device.open();
Receiver receiver = device.getReceiver();
// replace this with a real MidiMessage
//MidiMessage msg;
// use a real timestamp value from a MidiEvent
//long timeStamp;
receiver.send(msg, timeStamp);
receiver.close();
device.close();
 
}
} catch (MidiUnavailableException e) {
e.printStackTrace();
}
}
}
 

... taken from the book mentioned in the comment and it's related web site.
It gets a list of installed midi outputs and (supposedly) will send a midi event, yet it does not seem to work in the sense that the author does not provide adequate info on how to construct such a midi event, or the way that a specific "receiver" is selected.

Any more thoughts?

Panos
[ February 18, 2007: Message edited by: Panos Katergiathis ]

[Johny Doey]

I don't know nothing about this, but was wondering if this can hep you:

The Java Sound API specification provides low-level support for audio operations such as audio playback and capture (recording), mixing, MIDI sequencing, and MIDI synthesis in an extensible, flexible framework.

taken from: http://java.sun.com/products/java-media/sound/
Does that sound like it's ossible to do what you want? Either way I found this FAQ:
http://www.jsresources.org/faq_midi.html