Adding both AVCaptureMovieFileOutput and AVCaptureVideoDataOutput is supported in AVCaptureSession as seen in documentation (copied snippet below) but then when AVCaptureDevice is configured with ProRes422 codec, it fails unless one of the two outputs is removed from the capture session. It is very much reproducible on iPhone 14 pro running iOS 26.0. Prior to iOS 16, you can add an AVCaptureVideoDataOutput and an AVCaptureMovieFileOutput to the same session, but only one may have its connection active. If you attempt to enable both connections, the system chooses the movie file output as the active connection and disables the video data output’s connection. For apps that link against iOS 16 or later, this restriction no longer exists.

I want to confirm if this is a bug or a programming error. Very easy to reproduce it by modifying AVCam sample code. Steps to reproduce: Add AVCaptureVideoDataOutput to AVCaptureSession, no need to set delegate in AVCam sample code (CaptureService actor) private let videoDataOutput = AVCaptureVideoDataOutput() and then in configureSession method, add the following line try addOutput(videoDataOutput) if videoDataOutput.availableVideoPixelFormatTypes.contains(kCVPixelFormatType_420YpCbCr8BiPlanarFullRange) { videoDataOutput.videoSettings = [kCVPixelBufferPixelFormatTypeKey as AnyHashable as! String : kCVPixelFormatType_420YpCbCr8BiPlanarFullRange] } And next modify set HDR method: /// Sets whether the app captures HDR video. func setHDRVideoEnabled(_ isEnabled: Bool) { // Bracket the following configuration in a begin/commit configuration pair. captureSession.beginConfiguration() defer { captureSession.commitConfiguration() } do { // If the current device provides a 10-bit HDR format, enable it for use. if isEnabled, let format = currentDevice.activeFormat10BitVariant { try currentDevice.lockForConfiguration() currentDevice.activeFormat = format currentDevice.unlockForConfiguration() isHDRVideoEnabled = true if videoDataOutput.availableVideoPixelFormatTypes.contains(kCVPixelFormatType_420YpCbCr10BiPlanarVideoRange) { videoDataOutput.videoSettings = [kCVPixelBufferPixelFormatTypeKey as AnyHashable as! String : kCVPixelFormatType_420YpCbCr10BiPlanarVideoRange] } } else { captureSession.sessionPreset = .high isHDRVideoEnabled = false if videoDataOutput.availableVideoPixelFormatTypes.contains(kCVPixelFormatType_32BGRA) { print("Setting sdr pixel format \(kCVPixelFormatType_32BGRA)") videoDataOutput.videoSettings = [kCVPixelBufferPixelFormatTypeKey as AnyHashable as! String : kCVPixelFormatType_32BGRA] } try currentDevice.lockForConfiguration() currentDevice.activeColorSpace = .sRGB currentDevice.unlockForConfiguration() } } catch { logger.error("Unable to obtain lock on device and can't enable HDR video capture.") } The problem now is toggling HDR on and off no longer works in video mode. If after setting HDR on, you set HDR to off, active format of device does not change (setting sessionPreset has no effect). This does not happen if video data output is not added to session. Is there any workaround available?