which ffmpeg ?

[simoncn]

It is usually best to use the latest version available.

FFmpeg has a very large number of optional components, mostly in support of video formats that are not relevant for MinimServer use. If the larger executable includes all optional components and the smaller executable is a basic subset, this could explain the size difference. There is no improvement in sound quality from including unused components.

Entering the command 'ffmpeg' shows the version number as well as the configuration options (optional components) that were used when building the executable.