[pvrusb2] Aspect ratio trouble

[vdb128 at picaros.org]

> I tried to play a little with ctl_crop_XXX and ctl_cropcap_bounds_XXX
> without knowing what their good for...no use at all, couldn't change the
> values there.

The controls ctl_crop_height and ctl_crop_top would allow to remove the 
black bars.  This cropping is done by the analog decoder.  A typical 
PAL/625 letterbox frame is then 720x432 dot with an image aspect ratio 
of 20/11 or 16/9.  Alas, this capability is not in the kernel and the 
patches need to be ported to 2.6.29.

Here mplayer images 720x432 as 16/9 if the mpeg stream is tagged with a 
4/3 aspect ratio.  Its logic is, with rd the dot aspect ratio,
  tag=4/3  -> rd=16/15 -> ri=rd*Nh/Nv=16/15*720/432=16/9
and e.g.
  tag=16/9 -> rd=64/45 -> ri=rd*Nh/Nv=64/45*720/576=16/9
for a true 720x576 anamorphic frame.

You might try
$ mplayer -vo xv -ao alsa -vf crop=720:432:-1:-1 file.mpg
or for an rd=12/11 pal-plus capture
$ mplayer -vo xv -ao alsa -aspect 15/11 -vf crop=720:432:-1:-1 file.mpg
assuming 720x576 dot files.