MediaSourceBase (extends IMediaSource)

This abstract class implements the methods in IMediaSource that can are quite generic.

Of note are two introduced methods:

void OnDescriptionUpdated();

Description- Should be called in children to raise DescriptionUpdated event.

void OnSourceUpdated(IMediaSourceUpdateArgs args);

Description- Should be called in children to raise SourceUpdated event.
'args'- The IMediaSourceUpdateArgs used for updating.