Add custom metadata to video using AVFoundation

Question

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.

Answer 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.

Answer 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.

Answer 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.

Answer 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.