Valve has started testing the new Pyrowave video codec in the Steam beta. Its main task is to reduce latency when broadcasting games via Steam Remote Play. Unlike traditional codecs, Pyrowave makes little attempt to save bandwidth but still uses the GPU for encoding and decoding.
Low latency will come at the expense of huge bandwidth consumption. Valve warns that Pyrowave can use 5-10 times more bandwidth than other encoding options, so it recommends connecting two devices directly to the router via Gigabit Ethernet. When automatic bit rate control is disabled, the user can manually select a value between 100 and 500 Mbps.
The codec also supports HDR and YUV 4:4:4. The latter mode is disabled by default because it requires additional resources and traffic, but can significantly improve the clarity of text and small details when playing desktop or games at 4K.
Pyrowave remains an experimental feature, available in Steam Beta on Windows and macOS, and on Linux through the SteamRT3 test client. In the future, they plan to add support for the Steam Link mobile app. Meanwhile, Valve separately clarified that the technology is intended for use with regular on-screen broadcasts, not VR.
