Steam Client Beta Introduces Pyrowave Codec for Ultra-Low Latency Game Streaming

Steam's Remote Play feature now includes an experimental video codec called Pyrowave in the latest client beta, marking a shift toward more aggressive streaming development. The codec is designed to maximize available bandwidth to minimize latency, a characteristic Valve describes as unique.

Pyrowave can use up to 10 times more bandwidth than traditional streaming codecs like H.264, HEVC, and AV1. Because of this bandwidth requirement, Valve recommends the codec only for computers directly connected via gigabit ethernet on local networks.

The codec offers several technical advantages. It uses GPU encoding and decoding for low latency performance, supports full YUV 4:4:4 color reproduction useful for 4K desktop streaming, and automatically enables HDR when both client and host systems support it. Unlike conventional video codecs, Pyrowave processes each frame independently rather than relying on motion prediction, eliminating common compression techniques like entropy coding and discrete cosine transforms.

Hans-Kristian Arntzen, a frequent Valve collaborator known for work on the VKD3D-Proton framework, created the codec. Valve's testing demonstrates varying performance across different games: titles with fine foliage detail and temporal anti-aliasing like Expedition 33 present tougher test cases, while games with blurred backgrounds stream more easily. Early results were shown for Street Fighter 6 and Final Fantasy 7 Rebirth.

Pyrowave is currently available only on desktop Steam clients. Valve employee Sam Lantinga confirmed the codec will be added to the mobile app "soon". The codec is designed for traditional flat games rather than Steam Deck or VR experiences.