Ah yes that’s VP9, though you can also use an extension (or just a config tweak in Firefox), or Edge to view h264, which is minimum Sandy Bridge.

Intel Kaby Lake, Coffee Lake, Whiskey Lake, Amber Lake, Apollo Lake and Gemini Lake CPU families, AMD Raven Ridge APU family, and Nvidia Maxwell GM206, Pascal, Volta & Turing GPU families have full fixed function VP9 hardware decoding for highest decoding performance and power efficiency. (Wiki)