问题
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, AVAssetWritter also AVMutableComposition for creating the video.
回答1:
Use -[AVAssetWriter setMetadata:].
This is set to an NSArray of AVMutableMetadataItems. Note that you cannot set the value after writing has started.
Metadata keys and keyspaces are listed in AVMetadataFormat.h.
回答2:
When using AVMutableComposition, you can set the metadata property on the AVAssetExportSession when you go to write it out, rather than setting it on the asset (the composition) itself.
回答3:
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.
回答4:
Check out gusutils ==>
https://github.com/gpambrozio/GusUtils
There is an xcode project for creating a static library that lets you add metadata and geolocation information to your video and then persist to the assets library.
来源：https://stackoverflow.com/questions/10480991/add-custom-metadata-to-video-using-avfoundation