Scaling of QML VideoOutput/ShaderEffect (bilinear vs nearest-neighbour interpolation)

adrianf0

I have a problem with the low-resolution stream of a coloured grid being projected by QML VideoOutput and/or ShaderEffect. It becomes blur when I apply scale or anchors.fill (applies to VideoOutput only). I am not sure I am clear, but let's imagine that our original stream is a grid, e .g. a white-black chessboard. I would imagine that one could scale it to infinity preserving high quality/sharp output view (let's assume integer scale factor). Instead, I have the impression the mentioned QML objects use bilinear interpolation making the image blur, while I think in my case (more categorical than continuous data) the nearest-neighbour interpolation would be more appropriate. How to control this interpolation?
I have tried to set the smooth property in VideoOutput to false, but it doesn't impact the view at all (it's still blurry).

adrianf0

For VideOutput that does the trick:

    VideoOutput {
    ...
        layer.enabled: true
        smooth: false
    }

Unfortunately, it does't work with ShaderEffetct (the image is still blurry):

    ShaderEffect {
    ...
        layer.enabled: true
        smooth: false
        scale = 10
    }

Ready

Hello, do you find the solution? I'm also using the VideoOutput to display my frames and it also becomes blurry. I tried your suggestion:

 VideoOutput {
    ...
        layer.enabled: true
        smooth: false
    }

But this still doesn't help