I understand Youtube uses a variety of codecs and encoding parameters to serve videos to a multitude of platforms and clients. Maybe there are restrictions on s

I understand Youtube uses a variety of codecs and encoding parameters to serve videos to a multitude of platforms and clients. Maybe there are restrictions on some clients that force Youtube to pick a codec for them which makes ad embedding unprofitable. Circumventing embedded videos would then be as trivial as faking a particular client signature.