USB picture format

Hi all
TV model Philips 4000 series LCD TV 37PFL4606H 94 cm (37") Full HD 1080p digital TV with Pixel Plus HD
Software version 2.18

I am trying to watch a movie via the usb port. However the image is stretched and I cannot find any way to change the picture format while watching a movie from the usb flash drive.
I can change picture format to 16:9, widescreen, 4:3 etc while watching TV but not a movie from flash drive

Has anyone any idea how I can do this?

Thanks

Hi

Videos from USB or LAN can not be changed.
The Video will be shown "as it is".

Regards
Thomas

Thanks for your reply Thomas
Disappointing that this is the case. Very poor not to be able to adjust picture format for videos on USB. I expected more from Philips but its a bit late now to be finding out I suppose..............
Should have done more research