hi el FilouI can use the overscan setting of the TV but this loses image quality plus you can't finely tune by how many pixels you want to overscan.
The ideal solution (because cropping is only available on live TV and not on recorded)
maybe just try the madvr zoom options. they are very good for such things like that. works everywhere if enabled and it does not matter if it's with tv, videos or something else...
or did ya mean something completely different?