How to design a custom videoOutput?

The videoOutput I mean is

Code:

---

Rectangle {
        width: 320
        height: 240
 
        Camera{
            id: camera
        }
 
        VideoOutput {
            id: videoOutput
 
            anchors.fill: parent
            source: camera
        }    
 
        GammaAdjust {
            id: gammaAdjust
 
            anchors.fill: videoOutput
            source: videoOutput
            gamma: 0.5
        }
    }

---

How could design the videoOutput by myself?
Maybe this is the fastest and easiest way to save the
image after postprocessing,thanks

There is no way to capture the output without compromising the speed of QtQuick. What exactly are you trying to do?