Ask HN: Buld a server for live video encoding

I would like to build a server to encode live video into multiple quality streams(1080p, 720p, 480p...) on the fly.

I know google has their own Argos VCU, which is proprietary. Are there any alternatives on the open market or do I have to go with graphics cards? Also, which exact components would you actually use and how much data can it handle? Also I'd like AV1 hw support as well to future-proof it.