My Code::
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
VideoView vi
I'd recommend you have a look at Android's overview of supported media formats. This site covers everything from the first versions of Android to the latest:
Android Supported Media Formats
I'm guessing you're trying to include a video in your application, and that it needs to work on all devices, so I'd suggest you go ahead and try to encode a video with a profile similar to the SD (High quality)
listed on the above mentioned site.
There are plenty of free video converters available that you can use for encoding the video - one of them could be Freemake Video Converter.