A german court ruled youtube's obfuscation of video request signatures is an effective technological protection measure. YoutubeIE._decrypt_signature in youtube_dl/extractor/youtube.py bypasses this.
As a philosophical issue, since the youtube-dl code is running the cipher off of the code provided by youtube, just as my browser is, why is my browser not similarly circumventing this protection?
At least with CSS a key needed to be found by means separate from actually watching the DVD and wasn't shipped with the user in the same package as the video itself.
> why is my browser not similarly circumventing this protection?
Because your browser also runs the javascript that displays the ads (unless you've also blocked them, which I think could also be considered a "circumvention measure", IANAL).
If ads we're required, they could certainly not stream a video until the ads have been watched (or at least downloaded and the correct amount of time has passed), they could also insert ads as segments of video without having to transcode all videos for every user, but they don't.
> they could also insert ads as segments of video without having to transcode all videos for every user
That would work in a livestream very well, but not in a video. Imagine everyone getting adverts in the voice of live streamer in the different times of the livestream, and live chat getting time-dilated to compensate, without the streamer itself noticing.
Sorry this isn't really an argument. How can someone not make the argument regarding the browser in court and not have it align with the German court's prior finding?