AVTimedAnnotationWriter: Using Custom Annotation Metadata for Movie Writing and Playback

Last Revision:	Version 1.0, 2014-09-17 Minor update
Build Requirements:	Xcode 5.0 or later, iOS 8 or later
Runtime Requirements:	iOS 8 or later

Demonstrates how to use the AVAssetWriterInputMetadataAdaptor API to write circle annotation metadata during video playback. The captured movie file has video, audio and metadata track. The metadata track contains circle annotation which is vended during playback using AVPlayerItemMetadataOutput.