Immediate Audio Input & Output Android
As far as I can think it can be done in a very simple way. I haven't tried it,but you try it. I think it'll work:
Create two threads one for recording another for playing. Say the threads are TRecord and TPlay.
In TRecord's run method do this :
public void run(){
MediaRecorder mRecorder = null;
mRecorder = new MediaRecorder();
mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
mRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
mRecorder.setOutputFile(mFileName);
mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
try {
mRecorder.prepare();
} catch (IOException e) {
//todo
}
mRecorder.start();
}
And it TPlay's run method do this :
public void run() {
MediaPlayer mPlayer = null;
mPlayer = new MediaPlayer();
try {
mPlayer.setDataSource(mFileName);
mPlayer.prepare();
mPlayer.start();
} catch (IOException e) {
//todo
}
}
Now on mainactivity simply create two threads. First start the TRecord thread then Tplay . Try it.
here is the code for file extension:
mFileName = Environment.getExternalStorageDirectory().getAbsolutePath();
mFileName += "/audiorecordtest.3gp";
This is actually really tricky on Android. Google themselves have a very good (but slightly long) video explaining the issues.
They also have a page explaining their latency testing methods and benchmarks for various devices.
Essentially, stock Android can't do zero-latency audio, however there's nothing stopping hardware partners from adding the required hardware and platform extensions to do so.