How to subview a camera view?

Question

I am making an app that will let the user see themselves in a 'mirror' (the front facing camera on the device). I know of multiple ways of making a UIImageViewController with a view overlay, but I want my app to have it be the opposite way. In my app, I want the camera view to be a subview of the main view, without the shutter animation or the ability to capture photos or take videos and without it being full screen. Any ideas?

Answer 1

The best way to accomplish this is to not use the built-in UIImagePickerController, but rather use the AVFoundation classes.

You want to create an AVCaptureSession and set the appropriate outputs and inputs. Once it's configured you can get an AVCapturePreviewLayer which can be added to a view that you have configured in your view controller. The preview layer has a number of properties that allow you to control how the preview is displayed.

AVCaptureSession *session = [[AVCaptureSession alloc] init];
AVCaptureOutput *output = [[AVCaptureStillImageOutput alloc] init];
[session addOutput:output];

//Setup camera input
NSArray *possibleDevices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
//You could check for front or back camera here, but for simplicity just grab the first device
AVCaptureDevice *device = [possibleDevices objectAtIndex:0];
NSError *error = nil;
// create an input and add it to the session
AVCaptureDeviceInput* input = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error]; //Handle errors

//set the session preset 
session.sessionPreset = AVCaptureSessionPresetMedium; //Or other preset supported by the input device   
[session addInput:input];

AVCaptureVideoPreviewLayer *previewLayer = [AVCaptureVideoPreviewLayer layerWithSession:session];
//Set the preview layer frame
previewLayer.frame = self.cameraView.bounds;
//Now you can add this layer to a view of your view controller
[self.cameraView.layer addSublayer:previewLayer]
[session startRunning];

You can then use the captureStillImageAsynchronouslyFromConnection:completionHandler: of the output device to capture an image.

For more information on how AVFoundation is structured and examples on how to do this in more detail checkout the Apple Docs. Apple's AVCamDemo lays all of this out as well