Perceptual video quality assessment that gives the same score on every device.
VMAFx is a fork of Netflix/vmaf. Netflix's own reference tests run on every change, so the CPU scores stay the reference scores. On top of that, VMAFx scores on GPUs from every major vendor and holds each GPU version of a metric to the CPU's result bit for bit, with the evidence published.
| Repository | What it is |
|---|---|
| vmafx | The scoring library, CLI, FFmpeg integration, server and tooling: CUDA, SYCL, HIP and Metal backends, SIMD paths, containers and Helm. |
| pelorus | Encoder-side companion: a GPU pre-encode pipeline and the interop VMAFx reads (side data, QP reports, encoder parameters). |
| netflix-vmaf-contributions | Our fork of Netflix/vmaf, used to contribute fixes back upstream. |
- Correct before fast. The reference scores don't move. A faster path that changes a score is a bug, not a trade-off.
- Every vendor, same answer. NVIDIA, Intel, AMD and Apple GPUs, and the CPU's SIMD paths, all return the reference result, and published tables show where that is proven.
- Reproducible and verifiable. Signed releases, build provenance, SBOMs, and scores that can carry a record of exactly how they were produced.
- Upstream-friendly. We port Netflix's changes and keep the classic
libvmafAPI working for existing users.
The release badge above, the roadmap and the milestones are always current. This page doesn't repeat them, so it can't go stale.
- 📟 Have a GPU or Mac we haven't tested? Run the tester kit; see the hardware we need.
- 🙋 Questions and ideas: Discussions.
- 🧑💻 First contribution: good first issues and help wanted; start with CONTRIBUTING.
- 🔒 Security: report privately through security advisories.
Code written for VMAFx is licensed under EUPL-1.2. Code inherited from Netflix keeps its BSD-2-Clause-Patent licence. Each file's SPDX line is authoritative. Pelorus is EUPL-1.2 since v0.3.0; files it adds to FFmpeg are LGPL-2.1-or-later, and releases up to v0.2.2 stay BSD-2-Clause-Patent. See the vmafx LICENSE and NOTICE, and the Pelorus LICENSE.