No, not for me. I'm not transcoding 8k videos with it or anything like that. My use case is extracting thumbnails and video color info, basically transcoding to raw 100px x 100px clips and grabbing color info from that. The user would rather it takes as long as it takes than have to charge them a subscription fee to host the transcoding in the cloud.
Yup. WASM lacks the "domain specific" acceleration available to native code. So you miss out on any hardware codec support. Same is true for openSSL, there is a bunch of encryption acceleration in modern CPUs that WASM can't access at the moment.
I'd be very surprised. I haven't tried ffmpeg in WASM myself, but I do know that for Stockfish, a popular and very CPU-hungry chess engine, the difference is within 20-30% or so vs. an optimized native build.
