No audio when streaming ac3 with Android MediaPlayer

I've written a very simple application that loops through a list of videos and streams them from a nodejs server.

I'm just doing your basic video streaming set up with the Android MediaPlayer API, and everything works great, except for surround sound.

With Dolby Digital (ac3), I don't get any audio at all. I tried aac 5.1 and got audio, but it was downconverter to stereo.

public void setupVideoView(Uri videoAddress) {
    emVideoView.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
        @Override
        public void onPrepared(MediaPlayer mediaPlayer) {
            // Prepared Listener
        }
    });
    emVideoView.setOnErrorListener(new MediaPlayer.OnErrorListener() {
        @Override
        public boolean onError(MediaPlayer mp, int what, int extra) {
            // Error Listener
        }
    });
    emVideoView.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
        @Override
        public void onCompletion(MediaPlayer mediaPlayer) {
            setupVideoView(Uri.parse(video_url));
        }
    });
    emVideoView.setVideoURI(videoAddress);
}

I've searched for hours and haven't been able to find a solution. I would expect that Android, if the audio codec isn't supported, would simply pass it through so that something else down the chain could decode it. Maybe I don't fully understand how it works? Any help is greatly appreciated.

If the audio codec isn't available on the device then there's no way for Android MediaPlayer to decode it. LibVLC can convert audio to LPCM. Also, I believe ExoPlayer supports recoding audio but requires a lot more effort.