Apple will introduce Live Photo in iOS 9/iPhone 6s. Where is the file format documented?
A live photo has two resources. They are tied together with an asset identifier (a UUID as a string).
kCGImagePropertyMakerAppleDictionary
with [17 : assetIdentifier]
(17 is the Apple Maker Note Asset Identifier key).["com.apple.quicktime.content.identifier" : assetIdentifier]
. If using AVAsset
you can get this from asset.metadataForFormat(AVMetadataFormatQuickTimeMetadata)
["com.apple.quicktime.still-image-time" : 0xFF]
; The actual still image time matches up to the presentation timestamp for this metadata item. The payload seems to just be a single 0xFF
byte (aka -1) and can be ignored. If using an AVAssetReader
you can use CMSampleBufferGetOutputPresentationTimeStamp
to get this time.The assetIdentifier
is what ties the two items together and the timed metadata track is what tells the system where the still image sits in the movie timeline.