The core of kmplayer is in kmplayerpartbase.x. PartBase keeps
the list of Source objects (dvd/vcd/url/..) and Process objects
(mplayer/xine/gst/xv), controls the View or respond to its signals. Both
application as kpart (for plugin) have one PartBase. However, in case of
plugin for khtml, it's possible one PartBase controls multible View
objects (see tests/controls.html).

The View is the parent of ViewArea, PlayList and InfoWindow. ViewArea is
the parent of Viewer (the output for the backend players) and
ControlPanel.
In case of smil animations, the Viewer widget can be hidden or made
smaller so ViewArea background is where the rendering is done.
Classes in kmplayerplaylist.x are actually base for the XML playlist
formats (smil/asx/rss/..).

There is always one Source object active. A Source object sets up the
interface to the user as far possible, handling playlists and launching
backends. This is not fully worked out yet, eg. URLSource should be able
to launch multible backends for smil. Which probably means that PartBase
should have a list of Process factories and Source objects a list of 
running Process objects.

Backends are instances of Process and should be simple, just passing
data from/to external processes. A Recorder object is also a Process.
Though for mplayer, there is quite some code for output parsing.

The XML classes and parser provide a quick way for storing any XML file
in the playlist. Tree nodes build the tree themselves and recognized
multimedia elements more or less play the playlist themselves too.
The parser is build to recover from all kinds of typos. This is because
ASX is quite often full of XML errors that made other parsers give up,
eg. I've seen something like "<Title>Laurel & Hardy< / title>".

KMPlayerPart and KMPlayerApp are classes that use the above for plugin
and application.

Finally there is also a Settings class for general usage and for
launching the configure dialog.