Question

我用Frequency generator code产生了频率音。我的应用程序发出约13-14次声音后崩溃了

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：方法Tone.play（freq）中的错误 java.lang.IllegalStateException：在未初始化的AudioTrack上调用play（）。在android.media.AudioTrack.play（AudioTrack.java:1962）在com.milind.myapp.gpstrackingservice.Tone.playSound（Tone.java:47）在com.milind.myapp.gpstrackingservice.Tone.play（Tone.java:31）在com.milind.myapp.gpstrackingservice.MainActivity.onLocationChanged（MainActivity.java:155）在com.milind.myapp.gpstrackingservice.MyService.postLocationChange（MyService.java:207）在com.milind.myapp.gpstrackingservice.MyService.onLocationChanged（MyService.java:199）在android.location.LocationManager $ ListenerTransport._handleMessage（LocationManager.java:291）在android.location.LocationManager $ ListenerTransport.-wrap0（未知来源：0）在android.location.LocationManager $ ListenerTransport $ 1.handleMessage（LocationManager.java:236）在android.os.Handler.dispatchMessage（Handler.java:105）在android.os.Looper.loop（Looper.java:164）在android.app.ActivityThread.main（ActivityThread.java:6944）在java.lang.reflect.Method.invoke（本机方法）在com.android.internal.os.Zygote $ MethodAndArgsCaller.run（Zygote.java:327）在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会话数是有限的。

有人可以帮我解决在android上产生频率音调的问题吗

1 个答案: