Mp4ParserAudioMuxer.java

public class Mp4ParserAudioMuxer implements AudioMuxer {
    @Override
    public boolean mux(String videoFile, String audioFile, String outputFile) {
        Movie video;
        try {
            video = new MovieCreator().build(videoFile);
        } catch (RuntimeException e) {
            e.printStackTrace();
            return false;
        } catch (IOException e) {
            e.printStackTrace();
            return false;
        }

        Movie audio;
        try {
            audio = new MovieCreator().build(audioFile);
        } catch (IOException e) {
            e.printStackTrace();
            return false;
        } catch (NullPointerException e) {
            e.printStackTrace();
            return false;
        }

        Track audioTrack = audio.getTracks().get(0);
        video.addTrack(audioTrack);

        Container out = new DefaultMp4Builder().build(video);

        FileOutputStream fos;

        try {
            fos = new FileOutputStream(outputFile);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
            return false;
        }

        BufferedWritableFileByteChannel byteBufferByteChannel = 
            new BufferedWritableFileByteChannel(fos);

        try {
            out.writeContainer(byteBufferByteChannel);
            byteBufferByteChannel.close();
            fos.close();
        } catch (IOException e) {
            e.printStackTrace();
            return false;
        }

        return true;
    }
}