Maybe I should write a browser extension that actually does do this generically, by hooking the SourceBuffer interface, increasing the playback speed, and remuxing into a container format.
Even better, send a pull request to Blink to add this feature. It doesn't actually need to play the whole content, merely fire the right js events to get all the content loaded before doing a save.
It would ideally get integrated into the browser "downloading..." UI too, although I could imagine that being technically hard to do.
It would ideally get integrated into the browser "downloading..." UI too, although I could imagine that being technically hard to do.