I currently have a Loop back program for testing Audio on Android
devices.
It uses AudioRecord and AudioTrack to record PCM audio from the Mic
and play PCM audio out the earpiece.
Here is the code:
public class Record extends Thread
{
static final int bufferSize = 200000;
final short[] buffer = new short[bufferSize];
short[] readBuffer = new short[bufferSize];
public void run() {
isRecording = true;
android.os.Process.setThreadPriority
(android.os.Process.THREAD_PRIORITY_URGENT_AUDIO);
int buffersize = AudioRecord.getMinBufferSize(11025,
AudioFormat.CHANNEL_CONFIGURATION_MONO,
AudioFormat.ENCODING_PCM_16BIT);
arec = new
AudioRecord(MediaRecorder.AudioSource.MIC,
11025,
AudioFormat.CHANNEL_CONFIGURATION_MONO,
AudioFormat.ENCODING_PCM_16BIT,
buffersize);
atrack = new
AudioTrack(AudioManager.STREAM_VOICE_CALL,
11025,
AudioFormat.CHANNEL_CONFIGURATION_MONO,
AudioFormat.ENCODING_PCM_16BIT,
buffersize,
AudioTrack.MODE_STREAM);
atrack.setPlaybackRate(11025);
byte[] buffer = new byte[buffersize];
arec.startRecording();
atrack.play();
while(isRecording) {
arec.read(buffer, 0, buffersize);
atrack.write(buffer, 0,
buffer.length);
}
}
}
So as you can see in the creation of the AudioTrack and AudioRecord
the Encoding is supplied via the AudioFormat but this only allows 16
bit or 8 bit PCM.
I have my own G711 Codec implementation now and I want to be able to
encode the audio from the Mic and decode it going into the EarPiece,
So I have encode(short lin[], int offset, byte enc[], int frames) and
decode(byte enc[], short lin[], int frames) methods but I'm unsure as
to how to use them to encode and the decode the audio from the
AudioRecord and AudioTrack.
Can anyone help me or point me in the right direction?
--
You received this message because you are subscribed to the Google
Groups "Android Developers" group.
To post to this group, send email to android-developers@googlegroups.com
To unsubscribe from this group, send email to
android-developers+unsubscr...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/android-developers?hl=en
