VideoCustomCompositor.swift: import Foundation import AVFoundation import RealityKit enum CustomCompositorError: Int, Error, LocalizedError { case ciFilterFailedToProduceOutputImage = -1_000_001 case notSupportingMoreThanOneSources var errorDescription: String? { switch self { case .ciFilterFailedToProduceOutputImage: return "CIFilter does not produce an output image." case .notSupportingMoreThanOneSources: return "This custom compositor does not support blending of more than one source." } } } nonisolated final class VideoCustomCompositor: NSObject, AVVideoCompositing, @unchecked Sendable { private var isCancelled = false private var request: AVAsynchronousVideoCompositionRequest? var sourcePixelBufferAttributes: [String: any Sendable]? = [ String(kCVPixelBufferPixelFormatTypeKey): [kCVPixelFormatType_32BGRA], String(kCVPixelBufferMetalCompatibilityKey): true // Critical! ] var requiredPixelBufferAttributesForRenderContext: [String: any Sendable] = [ String(kCVPixelBufferPixelFormatTypeKey):[kCVPixelFormatType_32BGRA], String(kCVPixelBufferMetalCompatibilityKey): true ] func renderContextChanged(_ newRenderContext: AVVideoCompositionRenderContext) { return } func cancelAllPendingVideoCompositionRequests() { isCancelled = true request?.finishCancelledRequest() request = nil } func startRequest(_ request: AVAsynchronousVideoCompositionRequest) { self.request = request isCancelled = false // Reset cancellation status // guard let outputPixelBuffer = request.renderContext.newPixelBuffer() else { // print("No valid pixel buffer found. Returning.") // request.finish(with: CustomCompositorError.ciFilterFailedToProduceOutputImage) // return // } guard let requiredTrackIDs = request.videoCompositionInstruction.requiredSourceTrackIDs, !requiredTrackIDs.isEmpty else { print("No valid track IDs found in composition instruction.") return } let sourceCount = requiredTrackIDs.count if sourceCount > 1 { request.finish(with: CustomCompositorError.notSupportingMoreThanOneSources) return } if sourceCount == 1 { let sourceID = requiredTrackIDs[0] let sourceBuffer = request.sourceFrame(byTrackID: sourceID.value(of: Int32.self)!)! request.finish(withComposedVideoFrame: sourceBuffer) } // request.finish(withComposedVideoFrame: outputPixelBuffer) } }