AVCaptureDevice+Additions.h

#import <AVFoundation/AVFoundation.h>

@interface AVCaptureDevice(Additions)

+ (NSArray<AVCaptureDevice *>*)inputCameraDevices;
- (BOOL)isBuiltIn;
- (BOOL)hasVideoMedia;
- (BOOL)canOpenCamera;

@end

AVCaptureDevice+Additions.m

#import "AVCaptureDevice+Additions.h"

@implementation AVCaptureDevice(Additions)

+ (NSArray<AVCaptureDevice *>*)inputCameraDevices
{
    NSArray<AVCaptureDevice *>* videoDevices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
    NSArray<AVCaptureDevice *>* muxedDevices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeMuxed];

    return [videoDevices arrayByAddingObjectsFromArray:muxedDevices];
}

- (BOOL)isBuiltIn
{
    return [self transportType] == 'bltn' ? YES : NO;
}

- (BOOL)hasVideoMedia
{
    if ([self hasMediaType:AVMediaTypeMuxed] == NO) {
        return [self hasMediaType:AVMediaTypeVideo];
    }
    return YES;
}

- (BOOL)canOpenCamera
{
    BOOL canOpenCamera = NO;
    if ([self hasVideoMedia] && [self isConnected]) {
        canOpenCamera = [self isInUseByAnotherApplication] == NO ? YES : NO;
    }
    if ([self isBuiltIn]) {
        canOpenCamera = [[NSUserDefaults standardUserDefaults] boolForKey:@"DisableInternalCamera"] == YES ? NO : YES;
    }
    return canOpenCamera;
}

@end