A third options I didn't mentioned (because I don't use that often) is Grainy. Film make the end result more detailed but also bigger file size. If you use None, it get smaller files, but but areas that appears with same color or just gradually slope between two colors (like the blue sky) tend to be blocky, and doesn't look great. This will cause the conversion to take more time, but less information is trowed away (i.e.

Uncheck the 'use advanced configuration', and select Preset = Slower (or whatever the next slowest options is, but do not use the absolute slowest in the list unless it's for streaming).

This is a question of personal preferences - I suggest you have a little piece of the video (for testin) and convert it using quality 20 and 30, see what you think is better and choose something between. However that depends on resolution - a low resolution video is far more sensible to artefacts and should not use high values.

I tend to have my videos between 23 - 27 where anything beyond 30 I think is too bad for normal video.

When you want the video smaller you would probably want two things (third one about video quality issues): Just a little disclaimer: I'm currently sitting on a laptop where Avidemux is not installed, so some of the menu item captions is from the memory and may not be strictly correct named.

Quality factor - invers scale, closing to zeero goes towards uncompressed video.

Shotcut edit audio