[vdr] Grab function for NTSC

[Virgil Mocanu]

Hello everybody,
I'm trying to capture a screenshot by SVDRP but, apparently, it's not 
working properly for NTSC... I only see half of the image: either the even 
lines or the odd lines. I patched the code to duplicate the lines but the 
image quality is not very good.
Is this a known issue? It also might be a driver problem... but I don't know 
where the image is coming from.
Many thanks for any comments or suggestions!
Virgil