计算麦克风音量（试图找到最大值）

Question

我正在尝试查找麦克风输入的最大音量，因为我正在尝试查找某个声音的平均音量，以便我的程序可以通过音量识别它。 RMS计算方法来自这个网站（https://forums.oracle.com/forums/thread.jspa?threadID=1270831），我只是想弄清楚一切是如何工作的......

问题是，无论我发出多大的噪音，RMS 电平每次都输出为 0！所以我要么将我的 targetDataLine 设置完全错误并且它没有捕获音频......要么我在其他地方做错了什么。

这是我目前所拥有的：

import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.DataLine;
import javax.sound.sampled.LineUnavailableException;
import javax.sound.sampled.TargetDataLine;


public class MicrophoneTesting {

public MicrophoneTesting() {
    // TODO Auto-generated constructor stub
}

protected static int calculateRMSLevel(byte[] audioData)
{ // audioData might be buffered data read from a data line
    long lSum = 0;
    for(int i=0; i<audioData.length; i++)
        lSum = lSum + audioData[i];

    double dAvg = lSum / audioData.length;

    double sumMeanSquare = 0d;
    for(int j=0; j<audioData.length; j++)
        sumMeanSquare = sumMeanSquare + Math.pow(audioData[j] - dAvg, 2d);

    double averageMeanSquare = sumMeanSquare / audioData.length;
    return (int)(Math.pow(averageMeanSquare,0.5d) + 0.5);
}

public static void main(String[] args){

    // Open a TargetDataLine for getting microphone input & sound level
    TargetDataLine line = null;
    AudioFormat format = new AudioFormat(8000, 0, 1, true, true);
    DataLine.Info info = new DataLine.Info(TargetDataLine.class, format); //     format is an AudioFormat object
    if (!AudioSystem.isLineSupported(info)) {
        System.out.println("The line is not supported.");
    }
    // Obtain and open the line.
    try {
        line = (TargetDataLine) AudioSystem.getLine(info);
        line.open(format);
    } catch (LineUnavailableException ex) {
        System.out.println("The TargetDataLine is Unavailable.");
    }

    Timer t = new Timer(); // I used a timer here, code is below
    while(t.seconds < 2){
    byte[] bytes = new byte[line.getBufferSize() / 5];
    line.read(bytes, 0, bytes.length);
    System.out.println("RMS Level: " + calculateRMSLevel(bytes));
    }
}
}

定时器代码：

public class Timer implements Runnable{
    int seconds;
    Thread t;

public Timer() {
    this.seconds = 0;
    t = new Thread(this, "Clap Timer");
    t.start(); // Start the thread
}

@Override
public void run() {
    // TODO Auto-generated method stub
    while(seconds < 2)
    {
        //Wait 1 second
        try {                                
            Thread.sleep(1000);
        }
        catch(Exception e) {
            System.out.println("Waiting interupted.");
        }

        seconds++;
    }
}
}

Answer 1

当我在line.open() 之后添加line.start() 时，它起作用了。