When did Apple deprecated Quicklook? I can't find any mention of that. Generally when frameworks are deprecated it's noted here too:

https://developer.apple.com/library/mac/documentation/MacOSX...

Also no mention:

http://en.wikipedia.org/wiki/Quick_Look

Quick Look's media support is pretty sparse, but that's due to its use of Quicktime X for most video and audio. QL supports plugins from third parties though so... yes. You don't need to replace QL, just build a plugin for it.

AFAIK, there's been problems with building new plugins when it comes to video codecs since these Apple changes:

https://developer.apple.com/library/mac/technotes/tn2300/_in...

Here's more info on the change Apple made here with details on the issues it has caused with Quick Look:

http://apple.stackexchange.com/questions/114578/quick-look-s...

See the post at the bottom of the link above. In a nutshell, things like Perian that used to allow Quick Look (not to be confused with the QuickTime Player) to preview a bunch of video formats got hosed when Apple switched over to "AV Foundation" or something.

Considering how many less video formats work with Quick Look after "upgrading" from Snow Leopard to Mavericks, I personally consider it "depreciated" at least in principle.

Quite a lot of Mac users (especially those that work with a lot of video formats) have been waiting for something to fix this Quick Look issue for some years now.

The best you can do at the moment is install this to see thumbnails in Quick Look for some video formats:

https://github.com/Marginal/QLVideo

more info on the issue:

https://github.com/Marginal/QLVideo/issues/3

indeed, there are tons of modern QL plugins on GitHub even.

just a few I spotted in a quick search:

https://github.com/sindresorhus/quick-look-plugins

https://github.com/Nyx0uf/qlMoviePreview

https://github.com/Marginal/QLVideo

http://whomwah.github.io/qlstephen/

Do note that current plugins for Quick Look video do nothing more than be able to display static thumbnails of various video formats even if you have Perian installed. Unlike with Snow Leopard and Perian in the past, you won't see the actual video and audio run in Quick Look with AVI, MKV, etc formats.. That's where the libVLC can come in, I hope.

More info:

https://github.com/Marginal/QLVideo/issues/3

Actually I did that years ago with a friend. It's easy to revive.

I among many others would really appreciate that! Link? Can I help out?

If you know a bit about Obj-C, yes, it's quite simple.

That would be very nice, could you put it up on GitHub when you get a chance?