[beagle3]

Sounds reasonable. Just heads up that you may need to face those implications sooner or later. To the best of my knowledge (and IANAL, but I have worked extensively with lawyers on similar questions), if your ffmpeg.wasm contains any GPL code, you are obligated to provide the complete "original" source code of the product on request to anyone to whom you've distributed the compiled version.

You may want to check with a lawyer, and/or read the ffmpeg FAQ about that, and/or recompile with --disable-gpl --disable-nonfree - and that only brings you to the point where you need to let people use their own ffmpeg.wasm (and not be obligated to provide your source code).

https://www.ffmpeg.org/legal.html is actually required reading for anyone who uses ffmpeg in a product, commercial, free/libre or free/gratis.

I have an acquaintance who's a lawyer specializing in these issues, and he's usually called in to put out (legal) fires because people ignored open source licenses in commercial products. Copyright infringement laws are crazy complicated and in many ways incompatible with the modern ways of software, but they are what they are, and must be considered.