Question

我有一个midi文件，我已经使用以下代码在Android中使用MediaPlayer播放了该midi文件：

val mMediaPlayer = MediaPlayer.create(context, R.raw.test_ring_1)

mMediaPlayer?.start()

它默认使用一种乐器（例如钢琴）演奏，现在我想添加soundfont（sf2 / sf3）文件，以使用不同的乐器和混响效果来演奏Midi音符。

请指导达到预期结果的方法。

Answer 1

有两个库将用于使用SoundFont播放midi文件。

Midi Driver

只是用于在Android上播放MIDI音符的合成器。您可以将其与USB /蓝牙MIDI库一起使用来创建MIDI应用程序。

支持SoundFont2文件。

Android MIDI Library

此库提供了读取，操作和写入MIDI文件的接口。支持“播放”作为实时事件分发系统。该库不包括实际的音频播放或设备接口。

初始化SF2-SoundBank

SF2Soundbank sf = new SF2Soundbank(getAssets().open("test.sf2"));
        synth = new SoftSynthesizer();
        synth.open();
        synth.loadAllInstruments(sf);
        synth.getChannels()[0].programChange(0);
        synth.getChannels()[1].programChange(1);
        recv = synth.getReceiver();

播放midi文件中的Midi音符

MidiFile midiFile = new MidiFile(getAssets().open("test.mid"));

// Create a new MidiProcessor:
MidiProcessor processor = new MidiProcessor(midiFile);

// listen for all midi events:
processor.registerEventListener(new MidiEventListener() {
    @Override
    public void onStart(boolean fromBeginning) {

    }

    @Override
    public void onEvent(MidiEvent event, long ms) {

        if (event.getClass() == NoteOn.class) {

                NoteOn noteOn = ((NoteOn) event);

                try {
                    ShortMessage msg = new ShortMessage();
                    msg.setMessage(ShortMessage.NOTE_ON, channel, noteOn.getNoteValue(), noteOn.getVelocity());
                    recv.send(msg, ms);
                } catch (InvalidMidiDataException e) {
                    e.printStackTrace();
                }

            } else if (event.getClass() == NoteOff.class) {

                NoteOff noteOff = ((NoteOff) event);

                try {
                    ShortMessage msg = new ShortMessage();
                    msg.setMessage(ShortMessage.NOTE_ON, channel, noteOff.getNoteValue(), noteOff.getVelocity());
                    recv.send(msg, ms);
                } catch (InvalidMidiDataException e) {
                    e.printStackTrace();
                }

            }
    }

    @Override
    public void onStop(boolean finished) {

    }
}, MidiEvent.class);

// Start the processor:
processor.start();

可以定义SF频道

private int channel = 0;

Answer 2

我已经测试了它是否正常工作

    @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    try {
        SF2Soundbank sf = new SF2Soundbank(getAssets().open("SmallTimGM6mb.sf2"));
        synth = new SoftSynthesizer();
        synth.open();
        synth.loadAllInstruments(sf);
        synth.getChannels()[0].programChange(0);
        synth.getChannels()[1].programChange(1);
        recv = synth.getReceiver();
    } catch (IOException e) {
        e.printStackTrace();
    } catch (MidiUnavailableException e) {
        e.printStackTrace();
    }


    this.findViewById(R.id.piano).setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            int action = MotionEventCompat.getActionMasked(event);
            if (action == MotionEvent.ACTION_DOWN) {
                try {
                    ShortMessage msg = new ShortMessage();
                    msg.setMessage(ShortMessage.NOTE_ON, 0, 60, 127);
                    recv.send(msg, -1);
                } catch (InvalidMidiDataException e) {
                    e.printStackTrace();
                }
            } else if (action == MotionEvent.ACTION_UP || action == MotionEvent.ACTION_CANCEL) {
                try {
                    ShortMessage msg = new ShortMessage();
                    msg.setMessage(ShortMessage.NOTE_OFF, 0, 60, 127);
                    recv.send(msg, -1);
                } catch (InvalidMidiDataException e) {
                    e.printStackTrace();
                }
            }
            return true;
        }
    });

    this.findViewById(R.id.woodblock).setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            int action = MotionEventCompat.getActionMasked(event);
            if (action == MotionEvent.ACTION_DOWN) {
                try {
                    ShortMessage msg = new ShortMessage();
                    msg.setMessage(ShortMessage.NOTE_ON, 1, 60, 127);
                    recv.send(msg, -1);
                } catch (InvalidMidiDataException e) {
                    e.printStackTrace();
                }
            } else if (action == MotionEvent.ACTION_UP || action == MotionEvent.ACTION_CANCEL) {
                try {
                    ShortMessage msg = new ShortMessage();
                    msg.setMessage(ShortMessage.NOTE_OFF, 1, 60, 127);
                    recv.send(msg, -1);
                } catch (InvalidMidiDataException e) {
                    e.printStackTrace();
                }
            }
            return true;
        }
    });
}

别忘了在存储库下面包含sherlockmidi库，在下面的存储库中也可以找到示例。

https://github.com/agangzz/SherlockMidi

Android-使用MIDI文件播放SoundFont

2 个答案: