Windows Phone 8.1 Camera Initialisation - Access Denied Exception

Question

Using the 8.1 MediaCapture classes for Windows Phone.

Have declared the capabilities for "Audio" and "Webcam", which 90% is what would be the cause of the exception.

Kicker is, it works perfectly in the WP emulator, but breaks on an actual device.

Exact exception is here :

enter image description here

I have added a mountain of checks to make sure we aren't re-initializing the already initialized camera or trying to read before the initializations.. etc (as I assumed the issue was being caused by) So it is very unlikely to be that.

    private async Task InitializeCameraAsync()
    {
        if (_isInitialized)
        {
            Debug.WriteLine("Skipping unnecessary initialization");
            return;
        }

        Debug.WriteLine("Initializing camera media capture...");
        _deviceCapture = new MediaCapture();
        await _deviceCapture.InitializeAsync(new MediaCaptureInitializationSettings
        {
            VideoDeviceId = _cameraInfoCollection[_currentVideoDevice].Id,
            PhotoCaptureSource = PhotoCaptureSource.VideoPreview,
            AudioDeviceId = _microphoneInfoCollection[_currentAudioDevice].Id
            StreamingCaptureMode = StreamingCaptureMode.Video
        });
        Debug.WriteLine("Initialized camera media capture!");

        // For code completion only, unlikely to be relevant

        // Set up low-lag photo capture
        if (IsNotUsingInstantCapture)
        {
            Debug.WriteLine("Preparing low-lag photo capture");
            var imageEncoding = ImageEncodingProperties.CreateJpeg();
            imageEncoding.Width = PhotoCaptureWidth;
            imageEncoding.Height = PhotoCaptureHeight;
            _lowLagPhotoCapture = await _deviceCapture.PrepareLowLagPhotoCaptureAsync(imageEncoding);
        }

        _isInitialized = true;
        Debug.WriteLine("Initialized camera!");
    }

_mediacapture is then being bound to the .source of a xaml CaptureElement to show a preview.

The error sounds consistent with the behavior described at msdn.microsoft.com/en-us/library/windows/apps/hh768223. Is it possible that on the test device, the user account has accidentally denied access to the webcam or microphone for this app? — Chris Culter
That was my first though, however, being windows phone, from what I know, you as a user can't disable/enable access to the above. AFAIk this is only done initially when installing the app from store? — Kaelan Fouwels
There seems to be a problem (also with my device) - I had one simple program that used to take a photo and was working, after some updates now it's not working. I've also tried to run MSDN example without success. — Romasz
I have the exact same problem on both a Lumia 620 as well as the Lumia 1020. It is noteworthy though, that for a brief period of time I had the (front) camera working on the 620. After updating to the newest developer preview, I started getting access denied exceptions again, just like on the 1020. - No solution yet. — pkluz

WereWolfBoy WereWolfBoy · Accepted Answer · 2014-09-25T08:10:41

It was a temporary bug with the Windows api. It was fixed with the Windows Phone 8.1 update that was released the 24th of september 2014.

Windows Phone 8.1 Camera Initialisation - Access Denied Exception

1 Answers