AVCaptureDevice can't capture back camera - ios

Question

I'm trying to use the back camera off my iphone with AVCaptureDevice. I tried both AVCaptureDevicePositionBack and AVCaptureDevicePositionFront but it still uses the FrontCamera no matter what.
This is my code:
- (void)setupCamera
{
_captureDevice = nil;
NSArray *devices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
for (AVCaptureDevice *device in devices)
{
if (device.position == AVCaptureDevicePositionBack)
{
_captureDevice = device;
break;
}
}
}
- (void)turnCameraOn
{
NSError *error;
_session = [[AVCaptureSession alloc] init];
[_session beginConfiguration];
[_session setSessionPreset:AVCaptureSessionPresetMedium];
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:_captureDevice error:&error];
if (input == nil)
NSLog(#"%#", error);
[_session addInput:input];
AVCaptureVideoDataOutput *output = [[AVCaptureVideoDataOutput alloc] init];
[output setSampleBufferDelegate:self queue:dispatch_queue_create("myQueue", NULL)];
output.videoSettings = #{(id)kCVPixelBufferPixelFormatTypeKey:#(kCVPixelFormatType_32BGRA)};
output.alwaysDiscardsLateVideoFrames = YES;
[_session addOutput:output];
[_session commitConfiguration];
[_session startRunning];
}
- (void)turnCameraOff
{
[_session stopRunning];
_session = nil;
}

Answer 1

Use the following code:
AVCaptureDevicePosition desiredPosition;
if (isUsingFrontFacingCamera)
desiredPosition = AVCaptureDevicePositionBack;
else
desiredPosition = AVCaptureDevicePositionFront;
for (AVCaptureDevice *d in [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo]) {
if ([d position] == desiredPosition) {
[[captureVideoPreviewLayer session] beginConfiguration];
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:d error:nil];
for (AVCaptureInput *oldInput in [[captureVideoPreviewLayer session] inputs]) {
[[captureVideoPreviewLayer session] removeInput:oldInput];
}
[[captureVideoPreviewLayer session] addInput:input];
[[captureVideoPreviewLayer session] commitConfiguration];
break;
}
}