Java MIDI 外部设备传输到音序器的接收器

Question

我在从外部设备向音序器的接收器传输数据时遇到了一些问题。我可以毫无问题地将它传输到任何其他接收器。例如:

我有这两个类:

public class TestData {
    private Receiver receiver;

    public TestData(Receiver receiver)
    {
        this.receiver = receiver;
    }

    public void sendTestData() throws InvalidMidiDataException
    {
        ShortMessage shortMessage = new ShortMessage();
        shortMessage.setMessage(ShortMessage.NOTE_ON, 0, 50, 127);
        receiver.send(shortMessage, 123);
        shortMessage.setMessage(ShortMessage.NOTE_OFF, 0, 50, 0);
        receiver.send(shortMessage, 124);
        shortMessage.setMessage(ShortMessage.NOTE_ON, 0, 51, 127);
        receiver.send(shortMessage, 125);
        shortMessage.setMessage(ShortMessage.NOTE_OFF, 0, 51, 0);
        receiver.send(shortMessage, 126);
    }

}

和

public class MidiInputReceiver implements Receiver {
    public String name;
    Map<Byte, String> commandMap = new HashMap<Byte, String>();

    public MidiInputReceiver(String name) {
        this.name = name;
        commandMap.put((byte)-112, "Note On");
        commandMap.put((byte) -128, "Note Off");
        commandMap.put((byte) -48, "Channel Pressure");
        commandMap.put((byte) -80, "Continuous Controller");
    }
    public void send(MidiMessage msg, long timeStamp) {
        System.out.println("midi received");
        System.out.println("Timestamp: "  + timeStamp);
        byte[] b = msg.getMessage();

        if(b[0] != -48){
            //System.out.println("Message length: " + msg.getLength());
            System.out.println("Note command: " + commandMap.get(b[0]));
            System.out.println("Which note: " + b[1]);
            System.out.println("Note pressure: " + b[2]);
            System.out.println("---------------------");
        }else{
            //System.out.println("Message length: " + msg.getLength());
            System.out.println("Note command: " + commandMap.get(b[0]));
            System.out.println("Note Pressure: " + b[1]);
            System.out.println("---------------------");
        }
    }
    public void close() {}
}

这很好用:

sequencer = MidiSystem.getSequencer();
sequencer.open();
Sequence myseq = new Sequence(Sequence.PPQ, 10);
Track newTrack = myseq.createTrack();
sequencer.setSequence(myseq);
sequencer.setTickPosition(0);
sequencer.recordEnable(newTrack, -1);

TestData testData = new TestData(sequencer.getReceiver())
sequencer.startRecording();
testData.sendTestData();

这也适用:

MidiDevice device;
MidiDevice.Info[] infos;
infos = MidiSystem.getMidiDeviceInfo();
device = MidiSystem.getMidiDevice(infos[0]);
device.open();

Transmitter conTrans = device.getTransmitter();
conTrans.setReceiver(new MidiInputDevice("Test"));

因此 Controller 可以毫无问题地发送到我的自定义接收器。并且音序器的接收器从我的 TestData 类接收没有问题。但是以下(从我的外部 Controller 传输到我的音序器的接收器不起作用):

MidiDevice device;
MidiDevice.Info[] infos;
infos = MidiSystem.getMidiDeviceInfo();
device = MidiSystem.getMidiDevice(infos[0]);
device.open();

sequencer = MidiSystem.getSequencer();
sequencer.open();
Sequence myseq = new Sequence(Sequence.PPQ, 10);
Track newTrack = myseq.createTrack();
sequencer.setSequence(myseq);
sequencer.setTickPosition(0);
sequencer.recordEnable(newTrack, -1);

Transmitter conTrans = device.getTransmitter();
conTrans.setReceiver(sequencer.getReceiver());
sequencer.startRecording();

有什么我遗漏的吗？

编辑:好的，我可以看到轨道实际上正在接收 MidiEvents。我认为问题是时机。滴答数似乎很高，所以当我回放时，我认为它只是等待了非常非常长的时间才能回放录制开始时发生的事件。我认为这与将我的设备同步到我的音序器有关，但我不确定我的 SyncModes 应该设置成什么。

Answer 1

好吧，我想出了一个解决这个问题的方法。这似乎运作良好。在播放之前，我根据第一个滴答声调整所有滴答声。这将需要为每个轨道完成。

像这样:

int eventSize = sequencer.getSequence().getTracks()[0].size();
MidiEvent firstEvent = sequencer.getSequence().getTracks()[0].get(0);
long baseTime = firstEvent.getTick();

for(int i = 0; i < eventSize; i++){
    MidiEvent event = sequencer.getSequence().getTracks()[0].get(i);
    event.setTick(event.getTick() - baseTime);
}