Unable to Rewind/FF

I did see numerous threads on this, all of which say .mkv files on the xbox 360 can't be sped up at all (which is unfortunate), but I'm curious how to speed up other file types on a Samsung smart TV. The rewind/forward buttons on the samsung remote don't work, so you have to use the arrows which act pretty much the same, but is that really the one way to do it on a samsung tv? These functions work for all filetypes on my PS3, .mkvs are the only filetype that doesn't work on my 360 for rew/FF, and no filetypes allow these functions on my Samsung TV. 360/ps3 are wired, samsung is wireless.

Also, on a seperate note, why does only the 360 allow for skipping scenes entirely?

Thanks for any help.