mw_mediasource.java

DataSource.Factory dataSourceFactory = new DefaultDataSourceFactory(
        this,
        Util.getUserAgent(this, APP_NAME),
        (DefaultBandwidthMeter) bandwidthMeter);//note the type casting
ExtractorsFactory extractorsFactory = new DefaultExtractorsFactory();

//normally we would have this in string.xml or such instead of hardcoding
String waterUrl="https://storage.googleapis.com/android-tv/Sample%20videos/" +
                "Google%2B/Google%2B_%20Instant%20Upload.mp4"
MediaSource videoSource = new ExtractorMediaSource(
       Uri.parse(waterUrl),
       dataSourceFactory,
       extractorsFactory,
       null, null
);
player.prepare(videoSource);