[Martijn]

So what is the preferred/best way to improve this? Are there any other approaches that we could take? Do we want to limit the user experience on "powerful" hardware because there are lower power devices that will suffer? Or should we let the user choose when to perform the task?

I'd like a JSON request to extract the stream details.
I'd then use a script like Milhouse's texturecache to update this automatically (e.g. at night from a cron job).
You could also automate the extraction from external tools (like sickbeard).

Extraction on scan could be an option, but don't make it compulsory. I suspect it will make scans several times slower.

This sounds less than optimal and still requires some extra addon or extra effort from users.

Making it cleverer and letting it run during or after scan seems most preferable. Benchmarking would tell which is most preferred