Set the capture device color space to apple log not works.

I set the device format and colorspace to Apple Log and turn off the HDR, why the movie output is still in HDR format rather than ProRes Log?

Full runnable demo here: https://github.com/SpaceGrey/ColorSpaceDemo

        session.sessionPreset = .inputPriority
        // get the back camera
        let deviceDiscoverySession = AVCaptureDevice.DiscoverySession(deviceTypes: [.builtInWideAngleCamera], mediaType: .video, position: .back)
        backCamera = deviceDiscoverySession.devices.first!
        try! backCamera.lockForConfiguration()
        backCamera.automaticallyAdjustsVideoHDREnabled = false
        backCamera.isVideoHDREnabled = false
        let formats = backCamera.formats
        let appleLogFormat = formats.first { format in
            format.supportedColorSpaces.contains(.appleLog)
        }
        print(appleLogFormat!.supportedColorSpaces.contains(.appleLog))
        backCamera.activeFormat = appleLogFormat!
        backCamera.activeColorSpace = .appleLog
        print("colorspace is Apple Log \(backCamera.activeColorSpace == .appleLog)")
        
        backCamera.unlockForConfiguration()
        do {
            let input = try AVCaptureDeviceInput(device: backCamera)
            session.addInput(input)
        } catch {
            print(error.localizedDescription)
        }
        // add output
        output = AVCaptureMovieFileOutput()
        session.addOutput(output)
        let connection = output.connection(with: .video)!
        print(
        output.outputSettings(for: connection)
        )
        /*
         ["AVVideoWidthKey": 1920, "AVVideoHeightKey": 1080, "AVVideoCodecKey": apch,<----- prores has enabled.
         "AVVideoCompressionPropertiesKey": {
             AverageBitRate = 220029696;
             ExpectedFrameRate = 30;
             PrepareEncodedSampleBuffersForPaddedWrites = 1;
             PrioritizeEncodingSpeedOverQuality = 0;
             RealTime = 1;
         }]
         */
        previewSource = DefaultPreviewSource(session: session)
        queue.async {
            self.session.startRunning()
        }
        
    }