Default [Q] Possible to add audio to video on Android

I am developing an application that requires me to combine audio and video files. The audio is a short clip that will overlay with the video, and it can replace it if needed. I though that Android 4.3's MediaMuxer API would help, but I have been unable to get it to work for my needs. If anyone has suggestions for any way to do this I would greatly appreciate it!

Thanks,

Jeff D