AVFoundation workshop

Source code for AVFoundation workshop

Project

• UI code is mostly in storyboard, it doesnt bother you
• Methods we dont use are at the end of class
• Simple MVC architecture
• For learning purposes of AVFoundation
• Code doesnt contain pods or any 3rd party tools

Run

• Run app in simulator, don't use
• To run on device change your team in project settings

Tasks

1. CREATE PREVIEW IMAGE FROM ASSET

• task in AVAsset+ImagePreview, method called from ImageCollectionViewCell
• use AVAssetImageGenerator
• careful copying image is heavy operation

2. ASYNC LOAD ASSET KEYS

• task in PreviewViewController
• use asset loadValuesAsynchronously
• requiredAssetKeys are prepared for you
• check all keys are properly loaded
• set values from keys to metadataTextView
• dont forget set UI from loadValuesAsynchronously needs to be done on main thread

3. SET SLOW PLAYBACK TYPE

• task in PreviewViewController
• similar to other types
• try different rates
• check values from observered player item (eg canPlayReverse)
• check values printed in console after item restarts to play
• check available rate values at https://developer.apple.com/documentation/avfoundation/avplayeritem/1385591-canplayreverse

4. CREATE NEW ASSET MIXING VIDEO & SOUND

• task in VideoCompositionViewController
• create mutable track for video, check video asset has video track
• create mutable track for audio, check audio asset has audio track
• note reversed video is prepared for you
• try to set max time of video to make it nice and faster
• insert time ranges to proper tracks, compare audio video lenght
• create video composing instructions with layer instructions and set it properly to videoComposition
• careful video recorded in portrait would be rotated without updating video size
• once composition is ready video is exported, save button enabled a video played

5. BONUS - SEND ME FUNNY VIDEO As bonus try to use remote assets Dont forget that before reversing them or composing them they needed to be downloaded