fix: Set minFPS to 20 to allow maximum resolution photo

[mrousavy]

What

After research by @Dingenis, we found out that when setting FPS to 30 (min 30, max 30), the CameraX pipeline will reduce photo resolution to a very low value for some reason.

We are not sure if this is a bug or intended behaviour, that's why we will create an issue in the CameraX issue tracker.

As a temporary (or permanent?) solution for VisionCamera, we now change the FPS logic to not be a fixed rate (min 30 max 30), but instead lower the min FPS to 20 (min 20 max 30) - so it is variable.

In low light conditions, FPS will now drop to as low as 20, while in good light conditions it will go to the desired target FPS value.

Changes

Tested on

Related issues

• Temporarily fixes 🐛 The resolution of the PhotoFile is different than the format photo resolution #3031

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[mrousavy]

We could also add a prop something like fpsRange: 'variable' | 'fixed' which decides whether to use (min: 20, max: 30) or (min: 30, max: 30).

This behaviour also would work on iOS, right now it is fixed to min == max.