FFmpeg Batch AV Converter is an ffmepg gui, a front-end for Windows and Linux using Wine-Mono, that allows the use of the full potential of ffmpeg command line with a few mouse clicks in a convenient ...
UPDATE 03/13/2023: This plugin is now natively part of Krita as of Krita 5.0. I will keep this code here for reference, but you don't need to install this plugin any longer to get this functionality.