Microsoft Mesa Patch Could Improve AV1 Hardware Acceleration in WSL

Microsoft engineers have contributed new code to the open-source Mesa graphics library, with the main goal of improving video processing support inside Windows Subsystem for Linux.

According to Phoronix, the newly merged Mesa patch adds a prototype for AV1 video processing through DirectX 12 hardware acceleration. It also modifies a core HEVC variable, which could help improve reliability in future video workflows.

Microsoft wants better Mesa support in WSL

The patch targets a specific problem in WSL graphics support.

Linux graphical applications expect open-source graphics APIs such as Mesa. However, when those apps run inside WSL, they still rely on the Windows kernel and Windows graphics drivers underneath.

Microsoft’s new Mesa work helps connect those two layers more cleanly. Instead of forcing Linux apps to depend on GPU-specific workarounds, Mesa can pass certain video processing requests through Windows’ native graphics and media stack.

AV1 encoding gets DirectX 12 hardware acceleration

The most notable part of the patch is early AV1 hardware acceleration support.

With this change, Linux apps running in WSL will be able to request accelerated AV1 encoding. Mesa can then route that request through Windows Media Foundation and DirectX 12.

Since DirectX 12 works across multiple GPU vendors, this could give WSL broader hardware-accelerated video encoding support without needing separate Linux driver paths for every graphics card.

The patch is still a prototype

The current implementation remains limited.

Microsoft’s patch supports basic I-frame and P-frame encoding, but it does not yet support more advanced compression features. B-frames are also not supported at this stage.

That means this is not a complete AV1 acceleration stack yet. However, it gives Mesa and WSL a foundation for more advanced video processing work later.

WSL developers and video tools could benefit

The change should help developers and power users who run Linux workloads on Windows through WSL.

It could also benefit video processing tools, streaming apps, and AI workflows that ingest or process video. Hardware acceleration can reduce CPU usage and make encoding tasks faster on supported systems.

Mesa also benefits from Microsoft contributing the code upstream instead of building a separate Windows-only workaround.

The patch has now been merged into Mesa and is expected to appear in Mesa 26.2.

In related WSL news, Microsoft recently confirmed that WSL 3 does not exist. The company has also launched WSL Containers in public preview.

Via Neowin