Why does AVCaptureDevice.default return nil in swiftui? - swift

Question

I've been trying to create my own in-built camera but it's crashing when I try to set up the device.
func setUp() {
do {
self.session.beginConfiguration()
let device = AVCaptureDevice.default(.builtInDualCamera, for: .video, position: .front)
let input = try AVCaptureDeviceInput(device: device!)
if self.session.canAddInput(input) {
self.session.addInput(input)
}
if self.session.canAddOutput(self.output) {
self.session.addOutput(self.output)
}
self.session.commitConfiguration()
} catch {
print(error.localizedDescription)
}
}
When I execute the program, it crashed with the input because I try to force unwrap a nil value which is device.
I have set the required authorization so that the app can use the camera and it still end up with a nil value.
If anyone has any clue how to solve the problem it would be very appreciate

Answer 1

You're asking for a builtInDualCamera, i.e. one that supports:
Automatic switching from one camera to the other when the zoom factor, light level, and focus position allow.
Higher-quality zoom for still captures by fusing images from both cameras.
Depth data delivery by measuring the disparity of matched features between the wide and telephoto cameras.
Delivery of photos from constituent devices (wide and telephoto cameras) from a single photo capture request.
And you're requiring it to be on the front of the phone. I don't know any iPhone that has such a camera on the front (particularly the last one). You likely meant to request position: .back like in the example code. But keep in mind that not all phones have a dual camera on the back either.
You might want to use default(for:) to request the default "video" camera rather than requiring a specific type of camera. Alternately, you can use a AVCaptureDevice.DiscoverSession to find a camera based on specific characteristics.