I'm not an expert in this, but I don't think you'd be using similar hardware for video encoding and AI. Encoding uses a lot of compute, but it doesn't use much memory, whereas deep learning models (especially LLMs) use gobs of memory for both training and inference.
yes encoders are special purpose hardware mostly unrelated to AI
for consumers they tend to overlap because they way to get a good encode is to buy a good graphics card which might be more expensive due to AI and before that crypto
through on server center there are special purpose encode PCIe cards I think, through the ARM CPUs might also be an option
as a side note because people mix it up all the time Twitch is owned by Amazone but a distinct legal entity which has to pay Amazone for any AWS/Server stuff they use in the same way as other customer
If I had to guess, I'd speculate they're doing encoding on their Graviton ARM CPUs: https://community.arm.com/arm-community-blogs/b/infrastructu...