I\'m trying to render frames grabbed and converted from a video using ffmpeg to an OpenGL texture to be put on a quad. I\'ve pretty much exhausted google and not found an an
The file being used is a .wmv at 854x480, could this be the problem? The fact I'm just telling it to go 512x256?
Yes!
The striped pattern is an obvious indication that you're mismatching data sizes (row-size.). (Since the colors are correct, RGB vs BGR vs BGRA and n-components is correct.)
You're telling OpenGL that the texture you're uploading is 512x256 (which it isn't, AFAICT). Use the real dimensions (NPOT, your card ought to support it if it's not ancient).
Otherwise, resize/pad your data before uploading it as a 1024x512 texture.
Update
I'm more familiar with OpenGL that the other functions you're calling.
sxs_scale might to what you want (i.e. scaling the image down to a pot-size). However, scaling each frame might be slow.
I'd use the padding instead (which means, copy a small image (your video) into a part of a big texture (opengl)
Some other tips: