audio normalize

Hello, Can somebody point me to a "normalize" doc (the wiki is empty)? https://userbase.kde.org/Kdenlive/Manual/Effects/Audio_Correction/Normalise I use it, but find the level a bit high, and I don't see how to set this, I only see "gain 400%", "max gain 800%" "windows 75 frames" nothing

Devices compatibility table

Does anybody recommend a page with a list of video capture devices, being compatible with GNU/Linux? Is there some similar at kdenlive.org ? Thank you.