[pvrusb2] PAL-Plus support

[Mike Isely]

On Fri, 7 Nov 2008, Carsten Meier wrote:

> Hi,
> 
> I think you misunderstood me a little bit. Just to be sure we're talking
> about the same thing: http://en.wikipedia.org/wiki/Palplus .
> I know, that my PVRUSB2 doesn't have any decoder-hardware.
> 
> To assemble a true 16:9-picture of a PALPlus-broacast, only the lines
> hidden in the black letterbox-bars have to be reinserted into the
> picture. Can that be done with the PVRUSB2?
> 
> Regards,
> Carsten

This sounds like you are talking about what would otherwise by a normal 
broadcast but in anamorphic format.  In that case the thing that "adds" 
the "black bars" would be the device that actually displays the image, 
not the mpeg encoder.

The trick therefore is to get that display device to realize it is 
dealing with an anamorphic image.  There's a bit of metadata included in 
the mpeg2 stream which indicates the aspect ratio of the picture - that 
bit is set by default to 4:3.  All you should need to do therefore is 
change that so that the stream indicates 16:9 format instead.  There's 
an encoder setting you can adjust to do this.  Take a look at the 
"video_aspect" control in the sysfs interface.

  -Mike


-- 

Mike Isely
isely @ pobox (dot) com
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