private void playLocalAudio_UsingDescriptor() throws Exception {

    AssetFileDescriptor fileDesc = getResources().openRawResourceFd(
            R.raw.music_file);
    if (fileDesc != null) {

        mediaPlayer = new MediaPlayer();
        mediaPlayer.setDataSource(fileDesc.getFileDescriptor(), fileDesc
                .getStartOffset(), fileDesc.getLength());

        fileDesc.close();

        mediaPlayer.prepare();
        mediaPlayer.start();
    }
}