android - 有人可以帮我解决这个在Android上产生频率音调的问题吗

Question

我用Frequency generator code产生了频率音。我的应用程序生成音调约13-14次后崩溃

package com.milind.myapp.gpstrackingservice;

import android.media.AudioFormat;
import android.media.AudioManager;
import android.media.AudioTrack;
import android.os.Handler;
import android.util.Log;

public class Tone
{
    private static final String TAG = Tone.class.getSimpleName();

    // originally from http://marblemice.blogspot.com/2010/04/generate-and-play-tone-in-android.html
    // and modified by Steve Pomeroy <steve@staticfree.info>
    private final float duration = .12f; // seconds
    private final int sampleRate = 8000;
    private final int numSamples = (int)(Math.ceil(duration * sampleRate));
    private final double sample[] = new double[numSamples];
    private double freqOfTone = 440; // hz

    private final byte generatedSnd[] = new byte[2 * numSamples];

    Handler handler = new Handler();

    public void play(int freq)
    {
        // Use a new tread as this can take a while
        freqOfTone = freq;
        genTone();
        try {
            playSound();
        }
        catch (Throwable t)
        {
            Log.w(TAG, "Error in method Tone.play(freq)", t);
        }
    }


    public void playSound()
    {
        final AudioTrack audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC,
                sampleRate, AudioFormat.CHANNEL_CONFIGURATION_MONO,
                AudioFormat.ENCODING_PCM_16BIT, numSamples,
                AudioTrack.MODE_STATIC);
        audioTrack.write(generatedSnd, 0, generatedSnd.length);
        audioTrack.play();
    }

    public void genTone()
    {
        // fill out the array
        for (int i = 0; i < numSamples; ++i)
        {
            sample[i] = Math.sin(2 * Math.PI * i / (sampleRate / freqOfTone));
        }

        // convert to 16 bit pcm sound array
        // assumes the sample buffer is normalised.
        int idx = 0;
        for (final double dVal : sample)
        {
            // scale to maximum amplitude
            final short val = (short) ((dVal * 32767));
            // in 16 bit wav PCM, first byte is the low order byte
            generatedSnd[idx++] = (byte) (val & 0x00ff);
            generatedSnd[idx++] = (byte) ((val & 0xff00) >>> 8);
        }
    }
}

这是堆栈跟踪

2018-10-17 15:14:38.099 3690-3690/com.milind.myapp.gpstrackingservice W/Tone: Error in method Tone.play(freq) java.lang.IllegalStateException: play() called on uninitialized AudioTrack. at android.media.AudioTrack.play(AudioTrack.java:1962) at com.milind.myapp.gpstrackingservice.Tone.playSound(Tone.java:47) at com.milind.myapp.gpstrackingservice.Tone.play(Tone.java:31) at com.milind.myapp.gpstrackingservice.MainActivity.onLocationChanged(MainActivity.java:155) at com.milind.myapp.gpstrackingservice.MyService.postLocationChange(MyService.java:207) at com.milind.myapp.gpstrackingservice.MyService.onLocationChanged(MyService.java:199) at android.location.LocationManager$ListenerTransport._handleMessage(LocationManager.java:291) at android.location.LocationManager$ListenerTransport.-wrap0(Unknown Source:0) at android.location.LocationManager$ListenerTransport$1.handleMessage(LocationManager.java:236) at android.os.Handler.dispatchMessage(Handler.java:105) at android.os.Looper.loop(Looper.java:164) at android.app.ActivityThread.main(ActivityThread.java:6944) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:327) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1374)

Answer 1

我认为您应该关闭audioTrack-> audioTrack.close();播放声音后。打开的audioTrack session 数是有限的。