nvcamerasrc and QT5 QCamera

I’ve been researching lately to get video to stream to QCamera in a QT application (my camera work perfectly with gst-lauch & al). If I understand correctly I need to use the “nvcamerasrc” source got gstreamer. Is there anybody that has experience interfacing te two? QCamera is based on gstreamer but out of the box uses a v2l source. I can use the env variable QT_GSTREAMER_CAMERABIN_VIDEOSRC=nvcamerasrc which actually uses somewhat this plugin, but I get no image (I can see app starting streaming on the csi driver).
From the OpenCV examples it seems that nvcamerasrc needs to be used in conjunction with a quantity of option - I imagine this is why I get no image in my QT app. Anybody has experience how I can properly configure nvcamerasrc from qt?

We don’t have expertise on QT.

For OpenCV, you can refer to https://devtalk.nvidia.com/default/topic/1024245/jetson-tx2/opencv-3-3-and-integrated-camera-problems-/post/5210735/#5210735