I guess it's a compatibility issue, possibly some configurations run videos without acceleration. Maybe it's as simple as NVIDIA/AMD difference?
I did notice fairly significant GPU usage to play the menu, so you're probably onto something there. The FPS of the videos is also highly inconsistent. My example custom video always starts off very fast, and of course can be slowed down by many things.
Processor: Intel Core i7-4790K
Motherboard: ASUS ROG MAXIMUS VII HERO
Graphics: GIGABYTE GTX 1080
Memory: 32GB Corsair Pro Black
Damn. Not much I can do to criticise that setup
Must be a software config issue somewhere, I guess, but I couldn't really suggest where to look.
I tried encoding a 1-frame video @60fps WebM VP8 a while ago and I still got the annoying fps drops. I've had the videos disabled for a while now, perhaps I should give it another try.
I even notified Relic and asked if they could update COH2's internal WebM player to VP9. RelicCOH2.exe contains a hint that the internal version is still VP8;
WebM Project VP8 Decoder (Deprecated API) v0.9.7-p1 WebM Project VP8 Decoder
Hmm. Is there any chance its performance could be influenced by what codecs a person has installed on their computer? ie VLC, K-lite. I can only assume that wuff's issue is related to software configuration, because there's no knocking that hardware.
While this seems fun and all,won't it make so that people have to redownload the game with each update because of file integrity?
Patch checks should theoretically only do integrity checks on files that are changed by the patch. I can let you know for sure once the next patch comes out. That said, since you only have to paste the name of the video file into the corresponding lua file, the worst case scenario is that a few tiny text files get replaced. Almost no download time, and minimal inconvenience to restore.