>>1553796I use mpv (Linux and Windows) with the webm.lua - allows you to make webms (or other formats) on the fly while watching a video.
I also use Avidemux or Shotcut if more editing is needed, such as merging or dubbing.
>what type/settings does a 4chan WEBM needfor file sizes per board, see
https://github.com/4chan/4chan-API/blob/master/pages/Boards.md which links
https://a.4cdn.org/boards.json