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我發現下面的代碼會產生「噪音」。我希望能夠產生一種音調。據我瞭解，有一些涉及SIN的公式可以產生聲調。使用AudioTrack生成頻率
該行生成噪聲：rnd.nextBytes（noiseData）;
我試圖給所有數組元素手動賦值，但是沒有聲音。我發現了一個可以產生音調的代碼，但它不會流式傳輸它。當我試圖將數據傳遞給我的代碼時，會產生幾秒鐘的語氣，然後應用程序崩潰。
任何建議如何從中產生一個音調？由於
public class Internal extends Activity
{
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
public void onPlayClicked(View v)
{
start();
}
public void onStopClicked(View v)
{
stop();
}
boolean m_stop = false;
AudioTrack m_audioTrack;
Thread m_noiseThread;
Runnable m_noiseGenerator = new Runnable()
{
public void run()
{
Thread.currentThread().setPriority(Thread.MIN_PRIORITY);
/* 8000 bytes per second, 1000 bytes = 125 ms */
byte [] noiseData = new byte[1000];
Random rnd = new Random();
while(!m_stop)
{
rnd.nextBytes(noiseData);
m_audioTrack.write(noiseData, 0, noiseData.length);
}
}
};
void start()
{
m_stop = false;
/* 8000 bytes per second*/
m_audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC, 8000, AudioFormat.CHANNEL_OUT_MONO,
AudioFormat.ENCODING_PCM_8BIT, 8000 /* 1 second buffer */,
AudioTrack.MODE_STREAM);
m_audioTrack.play();
m_noiseThread = new Thread(m_noiseGenerator);
m_noiseThread.start();
}
void stop()
{
m_stop = true;
m_audioTrack.stop();
}
}
這是產生一個音的代碼，但是當我養活其輸出到我寫緩衝區，它扮演了一秒鐘，然後應用程序崩潰..即使我改「 AudioFormat.ENCODING_PCM_8BIT」到‘AudioFormat.ENCODING_PCM_16BIT’
private final int duration = 1; // seconds
private final int sampleRate = 8000;
private final int numSamples = duration * sampleRate;
private final double sample[] = new double[numSamples];
private final double freqOfTone = 440; // hz
private final byte generatedSnd[] = new byte[2 * numSamples];
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);
}
}