AudioTrack没有声音

Question

我正在尝试通过AudioTrack播放bytebeat。但它输出的只是沉默。 IDK为什么会这样，因为我是音频开发的新手。 PS。我已将未捕获的异常处理程序添加到bcontext，因此任何异常都将导致消息。

MainActivity。

package hg.melange.bytebeat;

import android.app.*;
import android.os.*;
import android.widget.*;
import android.view.*;
import android.content.*;

public class MainActivity extends Activity 
implements AdapterView.OnItemSelectedListener,
    CompoundButton.OnCheckedChangeListener,
    YesNoQuestion.Predicate,
    Thread.UncaughtExceptionHandler
{

    @Override
    public void uncaughtException(Thread p1, final Throwable p2)
    {
        MainActivity.this.runOnUiThread(new Runnable() {
            @Override
            public void run() {
        AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this)
            .setTitle(p2.getClass().getName())
            .setMessage(p2.getMessage())
            .setCancelable(false)
            .setPositiveButton("OK", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface p1, int p2)
                {
                    p1.dismiss();
                }
            });
        builder.create().show();
        }});
    }

    @Override
    public void yes()
    {
        try { this.bcontext.stop(); } catch(Throwable t) {}
        finally { this.finish(); }
    }

    @Override
    public void no()
    {
        // TODO: Implement this method
    }

    @Override
    public void onCheckedChanged(CompoundButton p1, boolean p2)
    {
        if (p1.getId() == R.id.playState)
        {
            bcontext.setİsPlaying(p2);
        }
    }

    @Override
    public void onItemSelected(AdapterView<?> p1, View p2, int p3, long p4)
    {
        String selected = ((ArrayAdapter<String>) p1.getAdapter()).getItem(p3);
        if (p1.getId() == R.id.samplingFreq)
        {
            bcontext.setSampleRate(Integer.parseInt(selected));
        }
        else if (p1.getId() == R.id.samplingType)
        {
            bcontext.setFloatbeat(selected.equalsIgnoreCase("floatbeat"));
        }
    }

    @Override
    public void onNothingSelected(AdapterView<?> p1)
    {
        // TODO: Implement this method
    }

    Spinner samplingFreq;
    Spinner samplingType;
    Switch playState;
    EditText scriptCode;
    TextView errorText;

    BytebeatContext bcontext;

    @Override
    public void onBackPressed()
    {
        YesNoQuestion ynq = new YesNoQuestion("Are you sure?", "Are you sure you want to exit?");
        ynq.setPredicate(this);
        ynq.query(this);
        if (ynq.getResult()) super.onBackPressed();
    }

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        samplingFreq = (Spinner) findViewById(R.id.samplingFreq);
        samplingFreq.setOnItemSelectedListener(this);

        ArrayAdapter<String> aptb = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1);
        aptb.add("8000");
        aptb.add("11025");
        aptb.add("22050");
        aptb.add("32000");
        aptb.add("44100");
        samplingFreq.setAdapter((SpinnerAdapter) aptb);

        samplingType = (Spinner) findViewById(R.id.samplingType);
        samplingType.setOnItemSelectedListener(this);

        ArrayAdapter<String> beats = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1);
        beats.add("bytebeat");
        beats.add("floatbeat");
        samplingType.setAdapter((SpinnerAdapter) beats);

        playState = (Switch) findViewById(R.id.playState);
        playState.setOnCheckedChangeListener(this);

        scriptCode = (EditText) findViewById(R.id.scriptCode);
        //scriptCode.setOnKeyListener(this);

        errorText = (TextView) findViewById(R.id.errorText);

        bcontext = new BytebeatContext(8000);
        bcontext.setRunning(true);
        bcontext.setUncaughtExceptionHandler(this);
        bcontext.start();
    }
}

BytebeatContext。

package hg.melange.bytebeat;
import android.media.*;

public class BytebeatContext extends Thread
{
    private int sampleRate;
    private boolean floatbeat;
    private boolean isPlaying;
    private String code;

    public BytebeatContext(int sampleRate)
    {
        this(sampleRate, false);
    }

    public BytebeatContext(int sampleRate, boolean floatbeat)
    {
        this.sampleRate = sampleRate;
        this.floatbeat = floatbeat;
    }

    public void setRunning(boolean running)
    {
        this.running = running;
    }

    public boolean isRunning()
    {
        return running;
    }

    public void setSampleRate(int sampleRate)
    {
        this.sampleRate = sampleRate;
    }

    public int getSampleRate()
    {
        return sampleRate;
    }

    public void setFloatbeat(boolean floatbeat)
    {
        this.floatbeat = floatbeat;
    }

    public boolean isFloatbeat()
    {
        return floatbeat;
    }

    public void setİsPlaying(boolean isPlaying)
    {
        this.isPlaying = isPlaying;
    }

    public boolean isİsPlaying()
    {
        return isPlaying;
    }

    public void setCode(String code)
    {
        this.code = code;
    }

    public String getCode()
    {
        return code;
    }

    private int bufsizbytes;

    private AudioTrack reinitTrack(AudioTrack old)
    {
        if (old != null)
        {
            try
            {
                old.stop();
                old.release();
            }
            catch (Throwable t)
            {

            }
        }

        bufsizbytes = AudioTrack.getMinBufferSize(getSampleRate(),
            AudioFormat.CHANNEL_CONFIGURATION_MONO, 
            AudioFormat.ENCODING_PCM_16BIT);

        AudioTrack newt = new AudioTrack(
            AudioManager.STREAM_MUSIC,
            getSampleRate(),
            AudioFormat.CHANNEL_CONFIGURATION_MONO,
            AudioFormat.ENCODING_PCM_16BIT,
            bufsizbytes,
            AudioTrack.MODE_STREAM);

        //newt.setPlaybackHeadPosition(0);
        newt.setStereoVolume(1.0f, 1.0f);

        return newt;
    }

    private boolean running;
    private long t;

    @Override
    public void run()
    {
        while (running)
        {
            AudioTrack at = reinitTrack(null);

            while (this.isİsPlaying())
            {
                if (at.getSampleRate() != getSampleRate())
                    break;

                // place output.

                short[] out = new short[bufsizbytes];

                for(int x=0; x<bufsizbytes; x++)
                {
                    out[(int)(t++)] = (short)(((((t*5&t>>8)&255)/128)-1)*32767);
                }

                at.write(out, 0, bufsizbytes);

                if(at.getPlayState() != AudioTrack.PLAYSTATE_PLAYING)
                    at.play();
            }

            t = 0;
            at = reinitTrack(at);
        }
    }
}