[MPlayer-users] Controlling screen size of WEBM and MKV files

[arthurpeabody]

I watch SNL by downloading the videos from the Tube of You.  They used to all be MP4s, but now some are MKVs (Matroska data) and WEBMs (whatever that is).  The files are all larger than my screen size.  I can resize the MP4s but not the MKVs and WEBMs: they come up with all the borders off screen.  No keystroke I have tried resizes them.  I haven't found an argument that sets the geometry (as has Firefox and Acrobat) at startup.

Have I missed them?  Is there a way to make these files fit to the screen?