> Anyway, OP doesn't do most of the things FFmpeg lists under their "License Compliance Checklist".
Legitimately asking, which points and how are they expected to handle it for this type of app (assuming they want to keep it closed source)? As far as I understand it they just need to credit the libraries?
The important thing is there has to be a clear separation between the proprietary parts and the LGPL parts of the app, and they have to provide a way to replace the LGPL parts. I have no idea how this is usually handled in the case of browser-based apps.
User must be able to replace the LGPL library with their own version of the library.