在 Java 中播放时将 midi 文件输出到控制台

Question

我正在尝试读取一个 MIDI 文件并在播放音符、音符和力度时输出。 This 会很好用，但它不会在播放音符时实时输出数据。播放midi的代码：

package midistep;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;

import javax.sound.midi.MidiSystem;
import javax.sound.midi.Sequencer;

public class MidiReadAndPlay {

    public static void main(String[] args) throws Exception {
        Sequencer sequencer;
        sequencer = MidiSystem.getSequencer();
        sequencer.open();

        InputStream is = new BufferedInputStream(new FileInputStream(new File("midifile.mid")));
        sequencer.setSequence(is);
        sequencer.start();
    }
}

我前面提到的问题的代码没有实时输出数据。它只是一次输出它。我希望它在播放音符时输出音序器数据，以便以后使用。

Answer 1

及时输出笔记笔记数据的解决方案是添加一个带有自定义代码的接收器：

public class MidiReadAndPlay {

    public static Receiver synthRcvr = new CustomReceiver();
    public static Transmitter seqTrans;
    public static Synthesizer synth;
    public static Sequencer sequencer;
    public static Sequence sequence;

    public static void main(String[] args) throws Exception {      
        sequencer = MidiSystem.getSequencer();
        sequence = MidiSystem.getSequence(new File("midi.mid"));

        Sequencer sequencer = MidiSystem.getSequencer();
        seqTrans = sequencer.getTransmitter();
        seqTrans.setReceiver(synthRcvr);

        sequencer.open(); 
        sequencer.setSequence(sequence);

        sequencer.start();
    }

}

接收者：

public class CustomReceiver implements Receiver {

    public CustomReceiver() {

    }
    public static final int NOTE_ON = 0x90;
    public static final int NOTE_OFF = 0x80;
    public static final String[] NOTE_NAMES = {"C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B"};

    @Override
    public void send(MidiMessage message, long timeStamp) {
        if (message instanceof ShortMessage) {
            ShortMessage sm = (ShortMessage) message;
            System.out.print("Channel: " + sm.getChannel() + " ");
            if (sm.getCommand() == NOTE_ON) {
                int key = sm.getData1();
                int octave = (key / 12)-1;
                int note = key % 12;
                String noteName = NOTE_NAMES[note];
                int velocity = sm.getData2();
                System.out.println("Note on, " + noteName + octave + " key=" + key + " velocity: " + velocity);
            } else if (sm.getCommand() == NOTE_OFF) {
                int key = sm.getData1();
                int octave = (key / 12)-1;
                int note = key % 12;
                String noteName = NOTE_NAMES[note];
                int velocity = sm.getData2();
                System.out.println("Note off, " + noteName + octave + " key=" + key + " velocity: " + velocity);
            } else {
                System.out.println("Command:" + sm.getCommand());
            }
        } else {
            System.out.println("Other message: " + message.getClass());
        }
    }

    @Override
    public void close() {

    }
}

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