How to check strength (intensity) of audio while recording?

问题

I am working on a voice recorder application. I want to know is there any way to find strength of the audio while recording it. I don't want to save the recording anywhere. I just want to show user if the sound being caught by the mic is louder then a predefined threshold or not.

Let's say if the sound being caught in below 2 decibel, it should show "low" in a red canvas. As soon as sound gets louder and passes 2 decibel threshold the canvas should turn green and show "high" message.

Is it possible using MediaRecorder or i haveto use AudioRecorder class. And how to work it out.

Thanks in advance

回答1:

You can start another thread when recording start and use getMaxAmplitude function to capture Amplitudes.

Below is the snippet.here we are taking sample for every 250 milliseconds and calculated max amplitude

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());
                } 

            }
        }

来源：https://stackoverflow.com/questions/11066470/how-to-check-strength-intensity-of-audio-while-recording