Languages used in VMAFX¶

VMAFX is a multi-language project. This page documents the role of each language, the minimum toolchain versions required to build the full project, and pointers to language-specific setup guides.

See docs/principles.md §8 for the policy constraints that govern which language is used for which role.

C / C++23 — core library¶

Used in: core/ (metric engine, feature extractors, GPU backend runtimes)

Minimum version: C23 (GCC ≥ 13 or Clang ≥ 17) / C++23 for new fork-added TUs. Netflix-inherited C files remain C99-compatible and are migrated per-TU only when a PR already touches the file.

Required toolchain:

# Linux — via package manager
sudo apt install gcc-13 clang-17   # or newer

# macOS — via Homebrew
brew install llvm

Build: see build-flags.md for Meson options.

Go — production tooling¶

Used in: cmd/ (future: cmd/vmafx-server, cmd/vmafx-mcp, cmd/vmafx-tune)

Minimum version: Go 1.25 (go.mod: go 1.26.4; toolchain 1.26.4)

Install:

# Linux / macOS — via official installer
# https://go.dev/dl/
# or via mise / asdf / homebrew

brew install go          # macOS
sudo apt install golang  # Ubuntu (may not be 1.25 yet — prefer upstream)

Verify:

go version  # must be >= go1.25

Workspace quick-start:

go build ./...     # or: make go-build
go test ./...      # or: make go-test
go vet ./...       # static analysis (required CI gate)

The Go module root is github.com/VMAFx/vmafx (declared in go.mod). Packages live under pkg/; binaries live under cmd/.

Rust — FFI bindings + feature-extractor pilots¶

Used in: bindings/rust/vmafx-sys (FFI bindings crate), core/src/feature/rust/ (optional pilot feature extractors)

Minimum version: Rust stable (≥ 1.80 recommended; latest stable preferred)

Install:

# Install rustup (manages Rust toolchains)
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
rustup update stable

Verify:

rustc --version   # must be stable
cargo --version

Workspace quick-start:

cargo check --all   # or: make rust-build
cargo test --all    # or: make rust-test

The Rust workspace manifest is at Cargo.toml in the repo root. Members are added by per-sweep PRs (the foundation PR adds none).

Python — ML training and dev scripts¶

Used in: ai/ (PyTorch + Lightning), tools/vmaf-tune/src/vmaftune/, mcp-server/vmaf-mcp/, scripts/

Minimum version: Python 3.11 (3.12 recommended)

Setup:

python3 -m venv .venv
source .venv/bin/activate
pip install -e ".[dev]"

See dev-mcp.md for the full dev-container setup which pins all Python dependencies in a stable environment.

GPU compute — CUDA / SYCL / HIP / Metal / Vulkan GLSL¶

Used in: core/src/feature/{cuda,sycl,hip}/ and core/src/{cuda,sycl}/

See the backend-specific guides:

• docs/backends/cuda.md
• docs/backends/sycl.md
• docs/backends/hip.md
• docs/backends/vulkan.md
• docs/backends/metal.md

CI toolchain matrix¶

References¶

• ADR-0702 — language modernization umbrella
• ADR-0686 — parent rebrand umbrella
• docs/principles.md §8 — policy constraints