FreeWili Player Movie Convertor

(wiliplayerconvert) A small desktop app that converts ordinary videos (MP4, MKV, MOV, …) into .fwmv files for the FreeWili movie player. They run on FreeWili2 (https://www.freewili.com ) or Adafruit FruitJam (www.adafruit.com/product/6200). It builds as a single self-contained binary — FFmpeg is statically linked, so there is nothing else to install. The code is cross-platform (Windows/Linux/macOS); so far it has been built and validated on Windows, with Linux/macOS wired in CI (see build/README.md).

What it does

• Pick multiple video files at once (native file dialog).
• Pick a destination folder (native folder dialog).
• Convert them all, with a per-file status list and an overall progress bar.
• Each input.mp4 becomes input.fwmv in the destination folder. If a name is already taken, it writes input_1.fwmv, input_2.fwmv, … (never overwrites).

Conversion uses the player's required settings: 480×270, 15 fps, MJPEG (quality 10), mono 16 kHz audio, full length (no size trimming). Sources are scaled to fit 480×270 and letterboxed; audio is downmixed to mono.

Using the output

Copy the .fwmv files to a USB thumb drive and plug it into the player:

• Format the drive as FAT/FAT32.
• Put the files in the root of the drive (subfolders are ignored).
• Up to 32 files; they play in alphabetical order and loop (e.g. 01-intro.fwmv, 02-main.fwmv).

Running

Once a release is published, download the binary for your OS and run it — no installer, no dependencies. (Windows may need the Microsoft Visual C++ runtime, which is present on virtually all machines.) Until then, build from source (below) or grab the artifact from a CI run.

Building from source

Building links FFmpeg statically and needs a one-time toolchain setup (Rust, a static FFmpeg, and LLVM/libclang for bindgen). The full, reproducible recipe — including the exact commands and why each piece is needed — is in build/README.md.

Quick version on the configured dev machine:

# FFmpeg code must build through the wrapper (sets up the MSVC/clang env):
powershell -ExecutionPolicy Bypass -File scripts/dev-cargo.ps1 build
powershell -ExecutionPolicy Bypass -File scripts/dev-cargo.ps1 test

# The pure-Rust format core has no FFmpeg dependency and tests with plain cargo:
cargo test --test adpcm --test fwmv_format --test fwmv_pack

How it's built

• src/fwmv/ — a dependency-free Rust implementation of the .fwmv v2 container, IMA-ADPCM audio, and the seek index. It is a byte-for-byte port of the reference Python packer and is verified against golden vectors generated from it.
• src/convert.rs — drives statically-linked FFmpeg (demux → decode → scale/letterbox/fps filter → MJPEG encode; audio → mono 16 kHz s16) and hands the frames + PCM to the packer.
• src/app.rs — the egui/eframe GUI with native dialogs and a background worker thread.

License

The application code is licensed under the MIT License (see LICENSE).

The binary statically links an LGPL build of FFmpeg (decoders + the built-in MJPEG encoder; no GPL components) and the BSD-licensed dav1d AV1 decoder. See build/README.md for the FFmpeg build configuration. Redistributing the binary is subject to FFmpeg's LGPL terms.