You can use Linthesia
I've tried it, and it doesn't work properly... to open it, I need a midi file, well I have one but I cannot play anything, it doesn't do anything with my piano (and it is well connected because VMPK is working). I doubt I'll get it up and running.
Their website is dormant and I use this site for download https://www.ubuntuupdates.org/package/c ... /linthesia
I wouldn't exclude something amiss on my side, though However, it looks fabulous being able to export it as a video would be also great .
By the way, I've tried my original approach (audacity) but with 16bit.
I guess some of the quality is gone thanks to the conversion to video, however - could you check it out and tell me whether you hear something annoying or something that generally 'spoils' the Internet content