AMD’s RadeonSI Gallium3D driver for next quarter’s Mesa 26.1 release is introducing a new low-latency video decode mode. This lower-latency video decoding comes with a trade-off of increased GPU power consumption.
Similar to the low-latency video encoding that has been worked on previously within the AMD Mesa code, for the RadeonSI driver with the Video Core Next (VCN) integration is a new low-latency video decode option for lowering video decoding latency in exchange for higher GPU power usage.
This merge landed in Mesa Git today. The low-latency decode can be enabled via the AMD_DEBUG=lowlatencydec environment variable. Due to the increased power consumption, it’s not enabled by default. Likewise, already within Mesa is AMD_DEBUG=lowlatencyenc as the low-latency encode option for RadeonSI and there being similar support with RADV Vulkan Video too.
No numbers on the latency benefit or power consumption impact were noted as part of this new AMD Radeon driver option in Mesa 26.1. The change was made by AMD’s David Rosca who has done a lot for the open-source AMD Linux video support in recent years.
