Android Video Circular Buffer with Sound

Question

I am using Google's Open Source Example: Grafika. I am using it's ContinuousCaptureActivity.java The CircularBuffer's Implementation is demonstrated in this Activity, but there is no audio included in the resultant Video file.

I want to add the Audio Recording functionality within this Activity and add the recorded Audio into the Video in the same CircularBuffered Fashion.

For achieving this i have explored the MediaCodec Library, which was introduced in 4.3+ versions. I have also used MediaMuxer to capture Video and Audio Streams and Muxed them into a single Video.

But, I am not sure about how to implement the Audio Recording functionality into the ContinuousCaptureActivity.java class. Any Help is highly appreciated.