Java MIDI 合成器 - 无法更换乐器
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Java MIDI Synthesizer - Can't change instruments
提问by Matt
I can't seem to get the instrument to change. I switch the value of the instrument but get nothing different on the output. I can only get a piano instrument to play no matter what value I try. Here is the simple code below. Does anyone have any suggestions? Or am I missing a fundamental of the instrument object?
我似乎无法改变乐器。我切换了仪器的值，但输出没有任何不同。无论我尝试什么价值，我都只能得到钢琴乐器。下面是简单的代码。有没有人有什么建议？或者我是否缺少仪器对象的基础知识？
import javax.sound.midi.*;
//import javax.sound.*;
public class Drum {
static int instrument = 45;
static int note = 100;
static int timbre = 0;
static int force = 100;
public static void main(String[] args) {
Synthesizer synth = null;
try {
synth = MidiSystem.getSynthesizer();
synth.open();
}
catch (Exception e) {
System.out.println(e);
}
Soundbank soundbank = synth.getDefaultSoundbank();
Instrument[] instr = soundbank.getInstruments();
synth.loadInstrument(instr[instrument]); //Changing this int (instrument) does nothing
MidiChannel[] mc = synth.getChannels();
mc[4].noteOn(note, force);
try { Thread.sleep(1000); }
catch(InterruptedException e) {}
System.out.println(instr[instrument].getName());
synth.close();
}
}
回答by Matti Virkkunen
You need to tell the channel to use the instrument. I admit I've never used MIDI in Java, but something like mc.programChange(instr.getPatch().getProgram())sounds promising.
您需要告诉频道使用该仪器。我承认我从未在 Java 中使用过 MIDI，但mc.programChange(instr.getPatch().getProgram())听起来很有希望。
回答by jfp
To play the percussion instruments you have to use the channel 10, that channel is used only for percussion instruments. (http://en.wikipedia.org/wiki/General_MIDI)
要演奏打击乐器，您必须使用通道 10，该通道仅用于打击乐器。(http://en.wikipedia.org/wiki/General_MIDI)
For example:
例如：
int instrument = 36;
Sequence sequence = new Sequence(Sequence.PPQ, 1);
Track track = sequence.createTrack();
ShortMessage sm = new ShortMessage( );
sm.setMessage(ShortMessage.PROGRAM_CHANGE, 9, instrument, 0); //9 ==> is the channel 10.
track.add(new MidiEvent(sm, 0));
then every note you add it will sound with percussion.
那么你添加的每个音符都会有打击乐的声音。
回答by Noah the Epic Guy
You need to send a program change event to the sequencer. How? Send a short message.
您需要向音序器发送程序更改事件。如何？发送一条短消息。
sound.setMessage(ShortMessage.PROGRAM_CHANGE, channel, instrument, channel);
long timeStam1p = -1;
Receiver rcv1r = MidiSystem.getReceiver();
rcv1r.send(sound, timeStam1p);
sound.setMessage(ShortMessage.NOTE_ON, channel, note, velocity);
long timeStamp = -1;
Receiver rcvr = MidiSystem.getReceiver();
rcvr.send(sound, timeStamp);
Variables are channel (int) note (int), instrument (int), velocity (int). Also, I suggest to learn midi events. Events are how a midi plays notes, stops notes, change instruments, tempo change, control changes, etc. I spent 2 years using a midi program.
变量是通道（int）音符（int）、乐器（int）、力度（int）。另外，我建议学习midi事件。事件是 MIDI 播放音符、停止音符、改变乐器、速度改变、控制改变等的方式。我花了 2 年时间使用 MIDI 程序。
