How to video record with specific sound programmatically in android?

Question

I have created functionality to record video in my app.

When I play a song, that song is recorded with video and a video file is created, similar to a dubshmash app

Answer 1

You can record video without audio and merge audio later on using mp4 parser like this:

/*
 * @param videoFile path to video file
 * @param audioFile path to audiofile
*/
    public String mux(String videoFile, String audioFile) {
        Movie video = null;
        try {
            video = new MovieCreator().build(videoFile);
        } catch (RuntimeException e) {
            e.printStackTrace();
            return null;
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }
    Movie audio = null;
    try {
        audio = new MovieCreator().build(audioFile);
    } catch (IOException e) {
        e.printStackTrace();
        return null;
    } catch (NullPointerException e) {

        e.printStackTrace();
        return null;
    }
    int size = audio.getTracks().size();
    Track audioTrack = audio.getTracks().get((size - 1));
    video.addTrack(audioTrack);

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

    File myDirectory = new File(Environment.getExternalStorageDirectory(), "/Folder Name");
    if (!myDirectory.exists()) {
        myDirectory.mkdirs();
    }
    filePath = myDirectory + "/video" + System.currentTimeMillis() + ".mp4";
    try {
        RandomAccessFile ram = new RandomAccessFile(String.format(filePath), "rw");
        FileChannel fc = ram.getChannel();
        out.writeContainer(fc);
        ram.close();
    } catch (IOException e) {
        e.printStackTrace();
        return null;
    }
return filePath;
}

In build.gradle add following dependency

compile 'com.googlecode.mp4parser:isoparser:1.0.5.4'