iPhone 7+, ios 11.2: Depth data delivery is not supported in the current configuration

Question

This bug is driving me mad. I'm trying to produce the absolute minimal code to get AVDepthData from an iPhone 7+ using its DualCam.

I have this code:

//
//  RecorderViewController.swift
//  ios-recorder-app


import UIKit
import AVFoundation


class RecorderViewController: UIViewController {

    @IBOutlet weak var previewView: UIView!

    @IBAction func onTapTakePhoto(_ sender: Any) {

        guard let capturePhotoOutput = self.capturePhotoOutput else { return }

        let photoSettings = AVCapturePhotoSettings()

        photoSettings.isDepthDataDeliveryEnabled = true //Error

        capturePhotoOutput.capturePhoto(with: photoSettings, delegate: self)

    }

    var session: AVCaptureSession?
    var videoPreviewLayer: AVCaptureVideoPreviewLayer?
    var capturePhotoOutput: AVCapturePhotoOutput?


    override func viewDidLoad() {
        super.viewDidLoad()

        AVCaptureDevice.requestAccess(for: .video, completionHandler: { _ in })

        let captureDevice = AVCaptureDevice.default(.builtInDualCamera, for: .depthData, position: .back)

        do {
            print(captureDevice!)
            let input = try AVCaptureDeviceInput(device: captureDevice!)

            self.capturePhotoOutput = AVCapturePhotoOutput()
            self.capturePhotoOutput?.isDepthDataDeliveryEnabled = true //Error

            self.session = AVCaptureSession()
            self.session?.addInput(input)

            self.videoPreviewLayer = AVCaptureVideoPreviewLayer(session: self.session!)
            self.videoPreviewLayer?.videoGravity = AVLayerVideoGravity.resizeAspectFill
            self.videoPreviewLayer?.frame = view.layer.bounds
            previewView.layer.addSublayer(self.videoPreviewLayer!)

            self.session?.addOutput(self.capturePhotoOutput!)
            self.session?.startRunning()

        } catch {
            print(error)
        }

    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

}

extension RecorderViewController : AVCapturePhotoCaptureDelegate {

    func photoOutput(_ output: AVCapturePhotoOutput, didFinishProcessingPhoto photo: AVCapturePhoto, error: Error?) {
        print(photo.depthData)

    }


}

If I comment out the lines that are marked with "Error" the code works as I would expect, and prints nil for depthData.

However, leaving the lines as they are, I get an exception. The error message states: AVCapturePhotoOutput setDepthDataDeliveryEnabled:] Depth data delivery is not supported in the current configuration.

How do I change the "current configuration" so that depth delivery is supported?

I've watched this video: https://developer.apple.com/videos/play/wwdc2017/507/ which was helpful, and I believe I've followed the exact steps required to make this work.

Any tips would be gratefully received!

Answer 1

There are two things that I needed to fix.

1. Set a sessionPreset to a format that supports depth, such as .photo.
2. Add the cameraPhotoOutput to session before setting .isDepthDataDeliveryEnabled = true.

Here is my minimal code for getting depth with photos:

//
//  RecorderViewController.swift
//  ios-recorder-app
//

import UIKit
import AVFoundation


class RecorderViewController: UIViewController {

    @IBOutlet weak var previewView: UIView!

    @IBAction func onTapTakePhoto(_ sender: Any) {

        guard var capturePhotoOutput = self.capturePhotoOutput else { return }

        var photoSettings = AVCapturePhotoSettings()
        photoSettings.isDepthDataDeliveryEnabled = true

        capturePhotoOutput.capturePhoto(with: photoSettings, delegate: self)

    }

    var session: AVCaptureSession?
    var videoPreviewLayer: AVCaptureVideoPreviewLayer?
    var capturePhotoOutput: AVCapturePhotoOutput?


    override func viewDidLoad() {
        super.viewDidLoad()

        AVCaptureDevice.requestAccess(for: .video, completionHandler: { _ in })

        let captureDevice = AVCaptureDevice.default(.builtInDualCamera, for: .video, position: .back)

        print(captureDevice!.activeDepthDataFormat)

        do{
            let input = try AVCaptureDeviceInput(device: captureDevice!)

            self.capturePhotoOutput = AVCapturePhotoOutput()

            self.session = AVCaptureSession()
            self.session?.beginConfiguration()
            self.session?.sessionPreset = .photo
            self.session?.addInput(input)

            self.videoPreviewLayer = AVCaptureVideoPreviewLayer(session: self.session!)
            self.videoPreviewLayer?.videoGravity = AVLayerVideoGravity.resizeAspectFill
            self.videoPreviewLayer?.frame = self.view.layer.bounds
            self.previewView.layer.addSublayer(self.videoPreviewLayer!)

            self.session?.addOutput(self.capturePhotoOutput!)
            self.session?.commitConfiguration()
            self.capturePhotoOutput?.isDepthDataDeliveryEnabled = true
            self.session?.startRunning()
        }
        catch{
            print(error)
        }

    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

}

extension RecorderViewController : AVCapturePhotoCaptureDelegate {

    func photoOutput(_ output: AVCapturePhotoOutput, didFinishProcessingPhoto photo: AVCapturePhoto, error: Error?) {
        print(photo.depthData)
    }


}