Apply CIFilter to video then add 2… | Apple Developer Forums

Apply CIFilter to video then add 2nd track

So I have two videos assets - one for background and one for foreground. What I want to achieve is to apply a CIFilter (ChromaKey) to the foreground video then add the background video so the two overlap. I can do the overlap or applying the filter but I can't put it together. Here is my code for videos overlap.

Code Block let bgAsset = AVURLAsset(url: URL(fileURLWithPath: Bundle.main.path(forResource: "bg", ofType: "mp4")!))
let fgAsset = AVURLAsset(url: URL(fileURLWithPath: Bundle.main.path(forResource: "fg", ofType: "mp4")!))
		
let mixComposition = AVMutableComposition()
		
let bgTrack = mixComposition.addMutableTrack(withMediaType: .video, preferredTrackID: kCMPersistentTrackID_Invalid)!
let fgTrack = mixComposition.addMutableTrack(withMediaType: .video, preferredTrackID: kCMPersistentTrackID_Invalid)!
try! bgTrack.insertTimeRange(CMTimeRange(start: .zero, duration: bgAsset.duration), of: bgAsset.tracks(withMediaType: .video).first!, at: .zero)
try! fgTrack.insertTimeRange(CMTimeRange(start: .zero, duration: bgAsset.duration), of: fgAsset.tracks(withMediaType: .video).first!, at: .zero)
		
let mainInstruction = AVMutableVideoCompositionInstruction()
mainInstruction.timeRange = CMTimeRange(start: .zero, duration: bgAsset.duration)
		
let firstLayerInstruction = AVMutableVideoCompositionLayerInstruction(assetTrack: bgTrack)
let secondLayerInstruction = AVMutableVideoCompositionLayerInstruction(assetTrack: fgTrack)
		
mainInstruction.layerInstructions = [secondLayerInstruction, firstLayerInstruction]
		
let videoComposition = AVMutableVideoComposition()
videoComposition.instructions = [mainInstruction]
videoComposition.frameDuration = CMTime(value: 1, timescale: 30)
videoComposition.renderSize = CGSize(width: 640, height: 480)
		
let url = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0].appendingPathComponent("overlapVideo.mov")
		
let exporter = AVAssetExportSession(asset: mixComposition, presetName: AVAssetExportPresetHighestQuality)!
exporter.outputURL = url
exporter.videoComposition = videoComposition
exporter.outputFileType = .mov
exporter.exportAsynchronously {
		print("finished")
}

Code Block
let bgAsset = AVURLAsset(url: URL(fileURLWithPath: Bundle.main.path(forResource: "bg", ofType: "mp4")!))
let fgAsset = AVURLAsset(url: URL(fileURLWithPath: Bundle.main.path(forResource: "fg", ofType: "mp4")!))

let mixComposition = AVMutableComposition()

let bgTrack = mixComposition.addMutableTrack(withMediaType: .video, preferredTrackID: kCMPersistentTrackID_Invalid)!
let fgTrack = mixComposition.addMutableTrack(withMediaType: .video, preferredTrackID: kCMPersistentTrackID_Invalid)!
try! bgTrack.insertTimeRange(CMTimeRange(start: .zero, duration: bgAsset.duration), of: bgAsset.tracks(withMediaType: .video).first!, at: .zero)
try! fgTrack.insertTimeRange(CMTimeRange(start: .zero, duration: bgAsset.duration), of: fgAsset.tracks(withMediaType: .video).first!, at: .zero)

let mainInstruction = AVMutableVideoCompositionInstruction()
mainInstruction.timeRange = CMTimeRange(start: .zero, duration: bgAsset.duration)

let firstLayerInstruction = AVMutableVideoCompositionLayerInstruction(assetTrack: bgTrack)
let secondLayerInstruction = AVMutableVideoCompositionLayerInstruction(assetTrack: fgTrack)

mainInstruction.layerInstructions = [secondLayerInstruction, firstLayerInstruction]

let videoComposition = AVMutableVideoComposition()
videoComposition.instructions = [mainInstruction]
videoComposition.frameDuration = CMTime(value: 1, timescale: 30)
videoComposition.renderSize = CGSize(width: 640, height: 480)

let url = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0].appendingPathComponent("overlapVideo.mov")

let exporter = AVAssetExportSession(asset: mixComposition, presetName: AVAssetExportPresetHighestQuality)!
exporter.outputURL = url
exporter.videoComposition = videoComposition
exporter.outputFileType = .mov
exporter.exportAsynchronously {
print("finished")
}

Thanks for any help!