custom compositor import AVFoundation final class CustomVideoCompositor: NSObject, AVVideoCompositing { enum CustomVideoCompositorError: Int, Error, LocalizedError { case sourcePixelBuffer } // HDR ? var sourcePixelBufferAttributes: [String: Any]? = [String(kCVPixelBufferPixelFormatTypeKey): [kCVPixelFormatType_32BGRA]] // HDR ? var requiredPixelBufferAttributesForRenderContext: [String: Any] = [String(kCVPixelBufferPixelFormatTypeKey): [kCVPixelFormatType_32BGRA]] // var supportsHDRSourceFrames: Bool = true func renderContextChanged(_ newRenderContext: AVVideoCompositionRenderContext) { print(#function) } func startRequest(_ request: AVAsynchronousVideoCompositionRequest) { guard let sourcePixelBuffer = request.sourcePixelBuffer else { print("request.sourcePixelBuffer is nil") request.finish(with: CustomVideoCompositorError.sourcePixelBuffer) return } guard let instruction = (request.videoCompositionInstruction as? CustomVideoCompositionInstruction) else { print("CustomVideoCompositionInstruction is nil") request.finish(withComposedVideoFrame: sourcePixelBuffer) return } guard let sourceTexture = sourcePixelBuffer.createTexture2(dependency: instruction.dependency) else { print("sourceTexture is nil") request.finish(withComposedVideoFrame: sourcePixelBuffer) return } guard let outputPixelBuffer = request.renderContext.newPixelBuffer() else { print("request.renderContext.newPixelBuffer()") request.finish(withComposedVideoFrame: sourcePixelBuffer) return } guard let outputTexture = outputPixelBuffer.createTexture2(dependency: instruction.dependency) else { print("request.renderContext.newPixelBuffer()") request.finish(withComposedVideoFrame: sourcePixelBuffer) return } instruction.offscreenRenderer.render( background: OffscreenRenderer.Background( model: instruction.textureModel, texture: sourceTexture, colorStrength: instruction.videoColorStrength ), outputTexture: outputTexture ) request.finish(withComposedVideoFrame: outputPixelBuffer) instruction.dependency.clearCache() // CVMetalTextureCacheFlush } }

custom instruction final class CustomVideoCompositionInstruction: NSObject, AVVideoCompositionInstructionProtocol { /// Custom var videoColorStrength = ColorStrength(red: 1, green: 1, blue: 1) let textureModel: TextureModel let dependency: Dependency let offscreenRenderer: OffscreenRenderer /// AVVideoCompositionInstructionProtocol var timeRange = CMTimeRange() var enablePostProcessing: Bool = false // to enable/disable AVVideoCompositionCoreAnimationTool(postProcessingAsVideoLayer: videoLayer, in: outputLayer) var containsTweening: Bool = false var requiredSourceTrackIDs: [NSValue]? var passthroughTrackID: CMPersistentTrackID = kCMPersistentTrackID_Invalid init?(videoTrack: AVAssetTrack, usedForExport: Bool, dependency: Dependency, timeRange: CMTimeRange) throws { let orientation: AVAssetTrack.VideoTrackOrientation = usedForExport ? videoTrack.orientation : .upSideDown guard let textureModel = try TextureModel(dependency: dependency, orientation: orientation) else { print("TextureModel is nil") return nil } guard let offscreenRenderer = OffscreenRenderer(device: dependency.device) else { print("OffscreenRenderer is nil") return nil } self.textureModel = textureModel self.dependency = dependency self.offscreenRenderer = offscreenRenderer self.requiredSourceTrackIDs = [NSNumber(value: videoTrack.trackID)] self.timeRange = timeRange containsTweening = true } }

Fixed. Instead CustomVideoCompositionInstruction(videoTrack: sourceVideoTrack, usedForExport: true, dependency: arguments.dependency, timeRange: timeRange) there should be CustomVideoCompositionInstruction(videoTrack: compositionVideoTrack, usedForExport: true, dependency: arguments.dependency, timeRange: timeRange)