How to force streaming video to play in SD

[Whitieiii]

I'm running into a problem and wanting some help... I'm wanting to force some sites to play streamed video in 240p or 360p or 480p without a manual setting on the site and it automatically assumes my internet can handle 1080p and forces that and I get content buffering.... my display is only 720p so some of the resolution is wasted as well... I'm limited to google chrome as the site won't run on anything else... any suggestions? I've installed a data saver extension for chrome and it just finds a way around it and forces 1080p and the content buffering happens again.... any help would be good! i'm willing to try everything