I want to add some info (metadata) to a video. I have found a way to retrieve metadata, but did not find any solution to set or modify metadata. I am using AVURLAsset<
If you need to do it "off line". I've used the id3taggenerator and related tools and they work great.
Checkout more info here: http://developer.apple.com/library/mac/#documentation/NetworkingInternet/Conceptual/StreamingMediaGuide/UsingHTTPLiveStreaming/UsingHTTPLiveStreaming.html
Or here's a tutorial I used for adding timed metadata that's pretty good: http://jmacmullin.wordpress.com/2010/11/03/adding-meta-data-to-video-in-ios/
If you want to add meta data in-app (as in a user records a video and add's their own meta data) I'm not sure there.