Question

我在从外部设备向序列发生器的接收器传输数据时遇到了一些麻烦。我没有问题将其传输给任何其他接收器。举个例子：

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();

这也有效：

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

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

因此控制器发送到我的自定义接收器没有问题。并且测序仪的接收器从我的TestData类接收没有问题。但是以下内容（从我的外部控制器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();

我有什么遗失的吗？

编辑：好吧，我可以看到赛道实际上正在接收MidiEvents。我认为问题在于时机。嘀嗒数字看起来非常高，所以当我去回放时，我认为它只是等待非常非常长的时间来播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应该设置为什么。

Answer 1

好的，我找到了解决这个问题的方法。这似乎运作良好。在播放之前，我会根据第一个刻度调整所有刻度。这需要针对每个轨道进行。

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);
}

Java MIDI外部设备传输到音序器的接收器

1 个答案: