Re: Codec problem.?
It is not a codec problem it more likely to be a graphics card problem
I always have has screen size resolution problems(picture not fitting screen size) and "juddering" on playing videos on my monitor. The latter I used to sort out by using a third party video program.
These problems eventually drove me to the point of having to do something about it.
As for screen resolution whatever I tried I could not get the picture to fill the screen, it always had a half inch black border around the picture. I was also getting pixels (sprinkles) occasional appearing right across the screen. went into display settings and could not expand resolution size. Eventually brain clicked and checked the MSI GTX 560 TI graphic card spec. Discovered it couldn't handle anything larger resolution than I already had.
Answer get a new graphics card.
So off I toddled to Our PC world computer shop and spoke to their computer guy." Graphics card" he said, "bound to be the problem but not to get one straight away until I found out the correct one for my computer."
So back home to look for an upgraded graphics card
THe old one was bought in 2012 an MSI GTX 560 Ti model, yes old for sure, so ordered and just arrived a GTX 1050 Ti updated version and what a difference. Now Have full screen and no more video Judder
so deleted the third party video program I was using. no need for it now
So Nom
check out the spec on your graphics card it may well not have enough GB on it, my old one was a 1 gb and he new one is 4 gb