Android - combining two MP4 files

Question

I'm writing an Android project where I'm recording several audio files. Therefore, I'm setting the following parameters. The recording works fine.

recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
recorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);

My problem is that each time I record, the output is written in a separate file. Now, I need to combine these files to one file. Does anyone have an idea how to combine several MPEG 4 files in an Android project?

Thanks for your help....

Answer 1

I would suggest using my mp4parser library then you don't have to deal with native libs. Have a look at the AppendExample. It does exactly what you want to do. Look out for the latest version. See below for AppendExample to get an idea how it works.

    Movie[] inMovies = new Movie[]{MovieCreator.build(Channels.newChannel(AppendExample.class.getResourceAsStream("/count-deutsch-audio.mp4"))),
            MovieCreator.build(Channels.newChannel(AppendExample.class.getResourceAsStream("/count-english-audio.mp4")))};

    List<Track> videoTracks = new LinkedList<Track>();
    List<Track> audioTracks = new LinkedList<Track>();

    for (Movie m : inMovies) {
        for (Track t : m.getTracks()) {
            if (t.getHandler().equals("soun")) {
                audioTracks.add(t);
            }
            if (t.getHandler().equals("vide")) {
                videoTracks.add(t);
            }
        }
    }

    Movie result = new Movie();

    if (audioTracks.size() > 0) {
        result.addTrack(new AppendTrack(audioTracks.toArray(new Track[audioTracks.size()])));
    }
    if (videoTracks.size() > 0) {
        result.addTrack(new AppendTrack(videoTracks.toArray(new Track[videoTracks.size()])));
    }

    IsoFile out = new DefaultMp4Builder().build(result);

    FileChannel fc = new RandomAccessFile(String.format("output.mp4"), "rw").getChannel();
    fc.position(0);
    out.getBox(fc);
    fc.close();