CreateFromMediaCaptureAsync Fails

[jlorek]

I'm trying to capture an image from a running camera preview.

    public async Task InitializeCamera()
    {
        var cameraID = await GetCameraID(Windows.Devices.Enumeration.Panel.Back);
        var settings = new MediaCaptureInitializationSettings
        {
            StreamingCaptureMode = StreamingCaptureMode.Video,
            VideoDeviceId = cameraID.Id,
        };

        _mediaCapture = new MediaCapture();
        await _mediaCapture.InitializeAsync(settings);
        _mediaCapture.SetPreviewRotation(VideoRotation.Clockwise90Degrees);

        Camera.Source = _mediaCapture;
        await _mediaCapture.StartPreviewAsync();

        MediaReader capture = await MediaReader.CreateFromMediaCaptureAsync(_mediaCapture);
        // ...
    }

But when calling CreateFromMediaCaptureAsync an exception is thrown:

An exception of type 'System.Exception' occurred in mscorlib.ni.dll but was not handled in user code
Additional information: The request is invalid in the current state. (Exception from HRESULT: 0xC00D36B2)

I don't get an exception when i uncomment the StartPreviewAsync line. But then i also get no preview...

[mmaitre314]

A couple of ways that should address that:

• Have MediaReader get frames from MediaCapture's record stream (instead of preview stream) by initializing MediaReader with MediaReaderCaptureInitializationSettings.CaptureStreamType = CaptureStreamType.Record
• Have the app manage the preview frame loop. See MediaCaptureReaderTestApp.MainPage.VideoLoop in the same repo for an example.