[SOLVED] Android echo cancellation

Android echo cancellation

I'm trying to develop an Audio Capture application using the AudioRecord class from Android API. Setting the audio source as MediaRecorder.AudioSource.MIC the application works, but when I try to use the echo cancellation setting by using MediaRecorder.AudioSource.VOICE_COMMUNICATION as audio source, I get an IllegalArgumentException when creating the AudioRecorder, but I don't know why.

My code is:

private static final int SAMPLE_RATE = 16000;
private static final int BIT_ENCODING = AudioFormat.ENCODING_PCM_16BIT;
private static final int CHANNEL_CONFIGURATION = AudioFormat.CHANNEL_CONFIGURATION_MONO;

private int m_i32BufferSize;

private AudioRecord m_AudioRecorder;

public caudioCapture ()
{
    super ();

    m_i32BufferSize = AudioRecord.getMinBufferSize(SAMPLE_RATE, CHANNEL_CONFIGURATION, BIT_ENCODING);

    //Create audio recorder object 
    try
    {
        m_AudioRecorder = new AudioRecord (MediaRecorder.AudioSource.VOICE_COMMUNICATION,SAMPLE_RATE,CHANNEL_CONFIGURATION,BIT_ENCODING,m_i32BufferSize);

    }
    catch (IllegalArgumentException e)
    {
        throw new IllegalArgumentException("Bad arguments on AudioRecorder creation", e);
    }

In my android manifest I have:

uses-permission android:name="android.permission.RECORD_AUDIO"

Maybe it is because I'm using a Samsung galaxy tab p1000 running with Android 2.2? Any ideas?

Thanks a lot!

Solution

Yes that is correct. The problem is that you are using Android 2.2. The new VOICE_COMMUNICATION got introduced in Android 3.0. When run on older versions you will get the DEFAULT source instead.