As far as I can tell, this uses: - libvips (wasm): for image conversion - ffmpeg (wasm): for audio conversion - ffmpeg (remote, via vertd): for video convers

As far as I can tell, this uses: - libvips (wasm): for image conversion - ffmpeg (wasm): for audio conversion - ffmpeg (remote, via vertd): for video conversion, with an option for the hoster to use wasm ffmpeg instead with some limitations (performance, maximum file size, etc) And from browsing the github, missing formats are usually caused by difficulties linking the libraries that handle those formats into the wasm libvps/ffmpeg