>>20014376There's no easy way.
For most of them, you can just do this. You don't have to download the sound, just have ffmpeg in your PATH if you're on Windows.
ffmpeg -i "soundpostfile.webm" -i "audio URL from the soundpost filename - change %2F back to / and put https:// back in there if it's missing" -c copy "output.mkv"
TL Note:
>Soundposts where the audio is much longer than the video will just have the video hold on the last frame instead of repeating like this one>Soundposts where the creator is a massive faggot that used an .mp4/.webm as the "sound" don't need this, just download the "sound">>20012807I wrote a .bat script that will automatically demux the audio from a pre-clipped video and try to make a WEBM that is under 3 MB. libvpx's VBR algorithm does whatever the fuck it wants, so sometimes it overshoots 3 MB.
https://pastebin.com/ZNbuLuhZ 