java - 用Android测量音量

Question

我想测量外部噪声的值，是否有一种简便的方法（示例函数可以帮助发现）？我在互联网上进行搜索，但大多数文章都是陈旧的，并告诉我们没有官方的方法可以做到这一点。

Answer 1

您可以在记录开始时启动另一个线程，并使用getMaxAmplitude函数捕获振幅。
下面是我们每250毫秒采样一次并计算出最大幅度的代码。

public void run() {
        int i = 0;
        while(i == 0) {

            try {
                sleep(250);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            if (mRecorder != null) {
                amplitude = mRecorder.getMaxAmplitude();

                //Here you can put condition (low/high)
                Log.i("AMPLITUDE", new Integer(amplitude).toString());
            } 

        }
    }

要么


引用此 link

AudioRecord recorder; // our recorder, must be initialized first
short[] buffer; // buffer where we will put captured samples
DataOutputStream output; // output stream to target file
boolean isRecording; // indicates if sound is currently being captured
ProgressBar pb; // our progress bar 
while (isRecording) {
    double sum = 0;
    int readSize = recorder.read(buffer, 0, buffer.length);
    for (int i = 0; i < readSize; i++) {
        output.writeShort(buffer [i]);
        sum += buffer [i] * buffer [i];
    }
    if (readSize > 0) {
        final double amplitude = sum / readSize;
        pb.setProgress((int) Math.sqrt(amplitude));
    }
}