[pvrusb2] crop defaults and the CVBS signal

[vdb128 at picaros.org]

The following is a bit off topic but might be useful.  When tracing 
the cause of a display aspect ratio error I ended up playing the files 

http://picaros.org/xorg/ntsc10.avi
http://picaros.org/xorg/pal1.avi
http://picaros.org/xorg/pal2.avi
http://picaros.org/xorg/pal3.avi
http://picaros.org/xorg/pal7.avi

through a Sigmatel based media player.  The recordings 

http://picaros.org/xorg/wdtvgenn.mpg normal, and 
http://picaros.org/xorg/wdtvgenw.mpg widescreen, 

show that a hblank=132+4 captures the full 720x576 frame.  Also, the 
player correctly crops pal1.avi and pal7.avi to fit the 15/11 and 
20/11 aperture aspect ratio.  

Servaas