apple-media

Configure an AVCaptureSession on a dedicated serial queue by adding an AVCaptureDeviceInput for the camera and outputs such as AVCapturePhotoOutput or AVCaptureMovieFileOutput, wrapped in beginConfiguration and commitConfiguration. Call startRunning off the main thread because it blocks.

Use PHPickerViewController in UIKit or PhotosPicker in SwiftUI, which run out of process and require no photo-library authorization. Load results through the item provider or loadTransferable, and only request PHPhotoLibrary authorization when you need direct library access.

Use VideoToolbox only for raw codec access such as real-time streaming, custom container muxing, or RTP transport. For standard file-based transcoding, AVAssetExportSession presets or AVAssetReader and AVAssetWriter are simpler and sufficient.

The crash occurs when the required Info.plist usage strings are missing. Add NSCameraUsageDescription, NSMicrophoneUsageDescription, NSPhotoLibraryUsageDescription, or NSPhotoLibraryAddUsageDescription before touching AVCaptureDevice or PHPhotoLibrary, and branch on every authorization status including limited.

Accessing synchronous properties like asset.duration blocks the main thread on remote assets and is deprecated. Load properties asynchronously with await asset.load(.isPlayable, .duration, .tracks) and observe AVPlayerItem.status before playing.

Use AVAssetImageGenerator with the async image(at:) or images(for:) APIs, setting requestedTimeToleranceBefore and After to zero for frame accuracy. For photo library grids, request a bounded target size with PHCachingImageManager instead of PHImageManagerMaximumSize to avoid memory spikes.