Check which version of ffmpeg it’s using and whether it has hardware acceleration for that codec.
Also bear in mind that you can’t hardware decode and hardware encode at the same time on the same device. If that’s what you’re trying to do it’s probably falling back on software silently in Windows instead of telling you.
And it’s pretty ignorant. If it were a picture of the white house instead of who’s in it for a couple years then it wouldn’t be so dumb. Better would be a picture of Congress.