No suitable user defined conversion from type to const Decklink Input Device

Question

I am trying to retrieve the frame from a Decklink input device for QT and pass this into a video sample queue for writing. The Line I am struggling with is how [this] is being passed as it says no suitable user defined conversion from type to const.

m_selectedDevice->OnVideoFrameArrival([this](CComPtr<IDeckLinkVideoInputFrame> frame) {
        if (Kraken_VideoRecorder().m_captureState == Kraken_VideoRecorder::CaptureState::Recording)
        {
            m_videoSampleQueue->VideoFrameArrived(frame);

            // Update UI with recording stream time
            //PostMessage(WM_UPDATE_STREAM_TIME_MESSAGE, 0, 0);
        }
    });


///This is defined as a QWidget
class DeckLinkInputPage : public QWidget
{
    Q_OBJECT

public:
//etc