[android] Play audio file from the assets directory

I have the following code:

AssetFileDescriptor afd = getAssets().openFd("AudioFile.mp3");
player = new MediaPlayer();
player.setDataSource(afd.getFileDescriptor());
player.prepare();
player.start();

The problem is that, when I run this code, it starts playing all the audio files in the assets directory, in alphabetical order instead of just playing the audio file I requested. What am I doing wrong? Is there a better way to play audio files from the assets directory?

Follow-up question: Is there a difference between keeping audio files in the assets directory and keeping them in the res/raw directory? Besides the fact that they don't get ids if they are in the assets directory. If I move the audio files to the res/raw folder then I have a problem with reusing MediaPlayers because there is no id parameter for setDataSource(). I can't find a good guideline for handling this kind of problem.

Here my static version:

public static void playAssetSound(Context context, String soundFileName) {
    try {
        MediaPlayer mediaPlayer = new MediaPlayer();

        AssetFileDescriptor descriptor = context.getAssets().openFd(soundFileName);
        mediaPlayer.setDataSource(descriptor.getFileDescriptor(), descriptor.getStartOffset(), descriptor.getLength());
        descriptor.close();

        mediaPlayer.prepare();
        mediaPlayer.setVolume(1f, 1f);
        mediaPlayer.setLooping(false);
        mediaPlayer.start();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

this works for me:

public static class eSound_Def
{
  private static Android.Media.MediaPlayer mpBeep;

  public static void InitSounds( Android.Content.Res.AssetManager Assets )
  {
    mpBeep = new Android.Media.MediaPlayer();

    InitSound_Beep( Assets );
  }

  private static void InitSound_Beep( Android.Content.Res.AssetManager Assets )
  {
    Android.Content.Res.AssetFileDescriptor AFD;

    AFD = Assets.OpenFd( "Sounds/beep-06.mp3" );
    mpBeep.SetDataSource( AFD.FileDescriptor, AFD.StartOffset, AFD.Length );
    AFD.Close();

    mpBeep.Prepare();
    mpBeep.SetVolume( 1f, 1f );
    mpBeep.Looping = false;
  }

  public static void PlaySound_Beep()
  {
    if (mpBeep.IsPlaying == true) 
    {
      mpBeep.Stop();
      mpBeep.Reset();
      InitSound_Beep(); 
    }
    mpBeep.Start();
  }
}

In main activity, on create:

protected override void OnCreate( Bundle savedInstanceState )
{
  base.OnCreate( savedInstanceState );
  SetContentView( Resource.Layout.lmain_activity );
  ...
  eSound_Def.InitSounds( Assets );
  ...
}

how to use in code (on button click):

private void bButton_Click( object sender, EventArgs e )
{
  eSound_Def.PlaySound_Beep();
}

Fix of above function for play and pause

  public void playBeep ( String word )
{
    try
    {
        if ( ( m == null ) )
        {

            m = new MediaPlayer ();
        }
        else if( m != null&&lastPlayed.equalsIgnoreCase (word)){
            m.stop();
            m.release ();
            m=null;
            lastPlayed="";
            return;
        }else if(m != null){
            m.release ();
            m = new MediaPlayer ();
        }
        lastPlayed=word;

        AssetFileDescriptor descriptor = context.getAssets ().openFd ( "rings/" + word + ".mp3" );
        long                start      = descriptor.getStartOffset ();
        long                end        = descriptor.getLength ();

        // get title
        // songTitle=songsList.get(songIndex).get("songTitle");
        // set the data source
        try
        {
            m.setDataSource ( descriptor.getFileDescriptor (), start, end );
        }
        catch ( Exception e )
        {
            Log.e ( "MUSIC SERVICE", "Error setting data source", e );
        }

        m.prepare ();
        m.setVolume ( 1f, 1f );
        // m.setLooping(true);
        m.start ();
    }
    catch ( Exception e )
    {
        e.printStackTrace ();
    }
}

start sound

startSound("mp3/ba.mp3");

method

private void startSound(String filename) {
    AssetFileDescriptor afd = null;
    try {
        afd = getResources().getAssets().openFd(filename);
    } catch (IOException e) {
        e.printStackTrace();
    }
    MediaPlayer player = new MediaPlayer();
    try {
        assert afd != null;
        player.setDataSource(afd.getFileDescriptor(), afd.getStartOffset(), afd.getLength());
    } catch (IOException e) {
        e.printStackTrace();
    }
    try {
        player.prepare();
    } catch (IOException e) {
        e.printStackTrace();
    }
    player.start();
}

This function will work properly :)

// MediaPlayer m; /*assume, somewhere in the global scope...*/

public void playBeep() {
    try {
        if (m.isPlaying()) {
            m.stop();
            m.release();
            m = new MediaPlayer();
        }

        AssetFileDescriptor descriptor = getAssets().openFd("beepbeep.mp3");
        m.setDataSource(descriptor.getFileDescriptor(), descriptor.getStartOffset(), descriptor.getLength());
        descriptor.close();

        m.prepare();
        m.setVolume(1f, 1f);
        m.setLooping(true);
        m.start();
    } catch (Exception e) {
        e.printStackTrace();
    }
}