iOS 13 error: Inconsistent state from AVCaptureStillImageOutput captureStillImageAsynchronouslyFromConnection - ios

Question

I'm developing command line tool that will take photo from camera (programmatically, without modal views or controls) and save it locally on device. So I'm trying to implement [AVCaptureStillImageOutput].
(Yes, I'm aware this has been deprecated since iOS 10, but my goal is to target also previous system version, starting iOS 9.)
So the problem I'm facing is fatal exception in function [captureStillImageAsynchronouslyFromConnection] that states Inconsistent state:
*** -[AVCaptureStillImageOutput captureStillImageAsynchronouslyFromConnection:completionHandler:] Inconsistent state
I've seen other SO threads and I think I implemented all the possible solutions to bypass this error but none worked that's why I'm posting this question with my code.
I've tested this code on iOS 9 and it works fine, but error rises on iOS 13. May the deprecation cause the error?
Anyway program compiles fine and works fine up until this specific function. All seems fine, front camera is found, session is started, videoConnection is active and enabled.. Still captureStillImageAsynchronouslyFromConnection returns exception.
Please find my code attached below. Any help much appreciated!
Header:
#import <AVFoundation/AVFoundation.h>
#import <Foundation/Foundation.h>
#interface CameraManager : NSObject
#property (retain) AVCaptureStillImageOutput *stillImageOutput;
#property (retain) AVCaptureConnection *videoConnection;
#property (retain) AVCaptureSession *session;
+ (instancetype)sharedInstance;
- (void) takePhoto;
#end
Class implementation:
#import "CameraManager.h"
#interface CameraManager()
#end
#implementation CameraManager
+ (instancetype)sharedInstance {
static CameraManager *sharedInstance = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
sharedInstance = [[CameraManager alloc] init];
});
return sharedInstance;
}
-(AVCaptureDevice *) frontFacingCameraIfAvailable{
NSArray *videoDevices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
AVCaptureDevice *captureDevice = nil;
for (AVCaptureDevice *device in videoDevices){
if (device.position == AVCaptureDevicePositionFront){
captureDevice = device;
break;
}
}
if (!captureDevice){
captureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
}
return captureDevice;
}
-(void) setupCaptureSession {
self.session = [[AVCaptureSession alloc] init];
self.session.sessionPreset = AVCaptureSessionPresetMedium;
AVCaptureVideoPreviewLayer *captureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:self.session];
NSError *error = nil;
AVCaptureDevice *device = [self frontFacingCameraIfAvailable];
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];
if (!input) {
NSLog(#"ERROR: trying to open camera: %#", error);
}
[self.session addInput:input];
self.stillImageOutput = [[AVCaptureStillImageOutput alloc] init];
NSDictionary *outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys: AVVideoCodecJPEG, AVVideoCodecKey, nil];
[self.stillImageOutput setOutputSettings:outputSettings];
[self.session addOutput:self.stillImageOutput];
[self.session startRunning];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(sessionWasInterrupted:) name:AVCaptureSessionWasInterruptedNotification object:self.session];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(sessionInterruptionEnded:) name:AVCaptureSessionInterruptionEndedNotification object:self.session];
}
- (void) sessionWasInterrupted:(NSNotification*)notification
{
AVCaptureSessionInterruptionReason reason = [notification.userInfo[AVCaptureSessionInterruptionReasonKey] integerValue];
NSLog(#"Capture session was interrupted with reason %ld", (long)reason);
}
- (void) sessionInterruptionEnded:(NSNotification*)notification
{
NSLog(#"sessionInterruptionEnded");
}
-(void) takePhoto {
[self setupCaptureSession];
self.videoConnection = nil;
for (AVCaptureConnection *connection in self.stillImageOutput.connections) {
for (AVCaptureInputPort *port in [connection inputPorts]) {
if ([[port mediaType] isEqual:AVMediaTypeVideo] ) {
self.videoConnection = connection;
break;
}
}
if (self.videoConnection) { break; }
}
NSLog(#"about to request a capture from: %#", self.stillImageOutput);
[self.videoConnection setVideoOrientation:AVCaptureVideoOrientationPortrait];
if (!self.videoConnection || !self.videoConnection.enabled || !self.videoConnection.active) {
NSLog(#"videoConnection not enabled or not active");
return;
} else {
NSLog(#"videoConnection enabled: %hhd, active: %hhd", (char)self.videoConnection.enabled, (char)self.videoConnection.active);
}
// NSLog(#"videoConnection: %#", self.videoConnection);
NSError *error;
if (error) {
NSLog(#"Error %#", error);
}
#try {
// here captureStillImageAsynchronouslyFromConnection crash with:
// *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: '*** -[AVCaptureStillImageOutput
captureStillImageAsynchronouslyFromConnection:completionHandler:] Inconsistent state'
[self.stillImageOutput captureStillImageAsynchronouslyFromConnection:self.videoConnection completionHandler: ^(CMSampleBufferRef imageSampleBuffer, NSError *error) {
NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageSampleBuffer];
NSLog(#"Here should have imageData %#", imageData);
}];
}
#catch (NSException *exception) {
NSLog(#"EXCEPTION %#", exception.reason);
}
#finally {
NSLog(#"Continue..");
}
}
#end