No, because they'd have to decompress and then recompress every stream. This would reduce already-lame quality (not that they'd particularly care) and require a bunch of resources.
Nah that's not how it works. Streaming video is usually cut up into small segments. By having a couple of variants per segment, they can serve you a unique and identifiable sequence of segments without having to decompress (and encrypt) them for each user.
mavamaarten|24 days ago