AVCaptureMovieFileOutput NSInvalidArgumentException нет активных/включенных соединений

- (id)initWithPreviewView:(UIView *)previewView {

    self = [super init];

    if (self) {

        NSError *error;

        self.captureSession = [[AVCaptureSession alloc] init];
        self.captureSession.sessionPreset = AVCaptureSessionPresetInputPriority;

        AVCaptureDevice *videoDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
        AVCaptureDeviceInput *videoIn = [AVCaptureDeviceInput deviceInputWithDevice:videoDevice error:&error];

        if (error) {
            NSLog(@"Video input creation failed");
            return nil;
        }

        if (![self.captureSession canAddInput:videoIn]) {
            NSLog(@"Video input add-to-session failed");
            return nil;
        }
        [self.captureSession addInput:videoIn];


        // save the default format
        self.defaultFormat = videoDevice.activeFormat;
        defaultVideoMaxFrameDuration = videoDevice.activeVideoMaxFrameDuration;


        AVCaptureDevice *audioDevice= [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio];
        AVCaptureDeviceInput *audioIn = [AVCaptureDeviceInput deviceInputWithDevice:audioDevice error:&error];
        [self.captureSession addInput:audioIn];

        self.fileOutput = [[AVCaptureMovieFileOutput alloc] init];
        [self.captureSession addOutput:self.fileOutput];


        self.previewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:self.captureSession];
        self.previewLayer.frame = previewView.bounds;
        self.previewLayer.contentsGravity = kCAGravityResizeAspectFill;
        self.previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
        [previewView.layer insertSublayer:self.previewLayer atIndex:0];

        [self.captureSession startRunning];
    }
    return self;
}

Мой код использует этот код инициализации, подобный этому, в viewDidLoad:

self.captureManager = [[AVCaptureManager alloc] initWithPreviewView:self.view];
self.captureManager.delegate = self;

Код, который фактически запускает и останавливает запись, выполняется из метода IBAction следующим образом:

- (IBAction)recButtonTapped:(id)sender {

    // REC START
    if (self.captureManager.isRecording == NO ) {

        NSLog(@"*** Start recording");

        // change UI
        [self.recBtn setImage:self.recStopImage
                     forState:UIControlStateNormal];
        self.fpsControl.enabled = NO;

        // timer start
        startTime = [[NSDate date] timeIntervalSince1970];
        self.timer = [NSTimer scheduledTimerWithTimeInterval:0.01
                                                      target:self
                                                    selector:@selector(timerHandler:)
                                                    userInfo:nil
                                                     repeats:YES];

        [self.captureManager startRecording];

    }
    // REC STOP
    else {

        NSLog(@"*** Stop recording");

        isNeededToSave = YES;
        [self.captureManager stopRecording];

        [self.timer invalidate];
        self.timer = nil;

        // change UI
        [self.recBtn setImage:self.recStartImage
                     forState:UIControlStateNormal];
        self.fpsControl.enabled = YES;

    }
}

РЕДАКТИРОВАТЬ. Я определенно закрываю сеанс в режиме просмотра фотографий, вот этот код. Я убедился, что он вызывается, когда я выхожу из контроллера просмотра фотографий.

        NSLog(@"RELEASE PHOTO SESSION NOW!");

        for(AVCaptureInput *input1 in _mySesh.inputs) {
            [_mySesh removeInput:input1];
        }

        for(AVCaptureOutput *output1 in _mySesh.outputs) {
            [_mySesh removeOutput:output1];
        }


        [_mySesh stopRunning];

        // Fix closing of session
        dispatch_after(
                       dispatch_time(0,500000000),
                       dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0),
                       ^{
                           _mySesh = nil;
                       }

        );

Согласно единственному ответу ниже, я пытался «отвязать» файл перед началом записи. Это все еще не сработало.

NSURL *fileURL = [NSURL URLWithString:[@"file://" stringByAppendingString:filePath]];

    //NSLog(@"Beginning to record to output file...");

    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), ^{

        // Wait for session to start
        //[NSThread sleepForTimeInterval:1.0];

        dispatch_async(dispatch_get_main_queue(), ^{

            // Ensure session is running
            if ( [self.captureSession isRunning] == NO ) {
                NSLog(@"Capture session is NOT running... Starting it now!");
                [self.captureSession startRunning];
            }
            else {
                NSLog(@"Capture session is ALREADY running...");
            }

            NSLog(@"File URL is: %@",fileURL);
            NSLog(@"FileOutput is: %@",self.fileOutput);

            // Delete the file
            unlink([[@"file://" stringByAppendingString:filePath] UTF8String]);

            [self.fileOutput startRecordingToOutputFileURL:fileURL recordingDelegate:self];

        });

    });

Просто для потомков я вызываю метод делегата didFinishRecordingToOutputFileAtURL:

- (void)                 captureOutput:(AVCaptureFileOutput *)captureOutput
   didFinishRecordingToOutputFileAtURL:(NSURL *)outputFileURL
                       fromConnections:(NSArray *)connections error:(NSError *)error
{

    // Print any errors
    if ( error ) {
        NSLog(@"Error Recording Video! %@",error.localizedDescription);
    }

    _isRecording = NO;

    if ([self.delegate respondsToSelector:@selector(didFinishRecordingToOutputFileAtURL:error:)]) {
        [self.delegate didFinishRecordingToOutputFileAtURL:outputFileURL error:error];
    }

}