Open Source Notices

Last updated: 24 September 2026

RadioCheck stands on other people's work. This page lists it, says what licence each part is used under, and tells you where to get the source. If we have got something wrong here, write to [email protected] and we will fix it.

Programs that ship as separate executables

Two pieces of software inside RadioCheck are not libraries linked into the app. They are standalone programs that RadioCheck starts and talks to, the way any app might call a command line tool. They keep their own licences, and you can replace them.

piper-worker: the voice synthesiser

Alan's speech is produced by Piper, which embeds eSpeak NG. Both are licensed under the GNU General Public License, version 3 or later.

Because the GPL requires that any program linking that code also be GPL, RadioCheck does not link it. Piper lives in a separate program called piper-worker, which is itself GPLv3. Its own program, its build scripts and the exact list of packages inside it ship with the app, in Contents/Resources/licenses/, and its complete source, Piper and eSpeak NG included, is hosted next to the download (see Source code below). RadioCheck communicates with it only through its standard input and output.

You may obtain, modify and redistribute piper-worker under the terms of the GPLv3. If a source link ever stops working, write to [email protected] and we will send you the same files.

ffmpeg and ffprobe: audio processing

FFmpeg is used to decode and encode audio. RadioCheck ships a build made specifically for it, compiled without the GPL-only components, so it is used under the GNU Lesser General Public License, version 2.1 or later. It includes LAME (LGPL) for MP3 encoding and libopus (BSD).

RadioCheck ships ffmpeg and ffprobe as two self-contained programs, with FFmpeg, LAME and libopus built into them, and runs them as separate processes. The exact build recipe (build_ffmpeg_lgpl.sh) ships inside the app bundle, in Contents/Resources/licenses/, next to the licence texts and BUILD_INFO.txt, which records the configuration, the source versions and their checksums. The recipe and the exact sources are also hosted next to the download (see Source code below). You may rebuild the two programs from those sources, modified or not, and replace them. If a source link ever stops working, write to [email protected] and we will send you the same files.

Source code

The complete source code of ffmpeg, ffprobe and piper-worker, exactly as built for the current release and including the scripts used to build them, is hosted in the same place as the download:

ffmpeg-8.0.3.tar.xz: FFmpeg source
sha256 6136812ea6d4e68bdba27e33c2a94382711cdf4f8602ffef056ff792bd6f9818
ffmpeg-8.0.3.tar.xz.asc: FFmpeg's release signature for it
sha256 975f9512458fc39cacf35a9496f51c9d82e3a3b684a9db111bedcfa523f2b2b8
lame-3.100.tar.gz: LAME source
sha256 ddfe36cab873794038ae2c1210557ad34857a4b6bdc515785d1da9e175b1da1e
opus-1.6.1.tar.gz: libopus source
sha256 6ffcb593207be92584df15b32466ed64bbec99109f007c82205f0194572411a1
build_ffmpeg_lgpl.sh: the build recipe for ffmpeg and ffprobe
sha256 54526cdc71f1cab468c49d0b5185ceba8f2d7b45a2724a3fabdcea1ce7b19e3a
piper1-gpl-077c783a28a8eb31c269bf2fc79e1f834d265809.tar.gz: Piper source (piper-tts)
sha256 b5123240213095615b5d92839695e143b7fee06992bddf53a2f818561846c089
espeak-ng-212928b394a96e8fd2096616bfd54e17845c48f6.tar.gz: eSpeak NG source, at the commit Piper builds in
sha256 be7268685a285f18a11092919b0c5892075d81ae1492a0e073fb858f7d927306
worker.py.source: piper-worker's own program
sha256 9de135d1868af5e05b261a7edb670b357d286c99703a96c89f9fe5622e5f9bc6
build_piper_worker.sh: the build recipe for piper-worker
sha256 c00d97240820c1fcfc88e66f629d7e75bed558b13e9b74fdf33504935763710d
_build_python.sh: the Python used to build piper-worker
sha256 4a52a1e431ac21f86b19b24c3b44955c454d3a892d58942e3f4134a6e75e4484
piper-worker-requirements.lock: every package inside piper-worker, exact versions and sha256
sha256 a802acfe46aea09addfcc20ca05bcb3774ac1a2bfce15de384fa186145b27394
SHA256SUMS: sha256 of every file above

Every release has its own folder, https://dl.radiocheckapp.com/source/<version>/, and each copy of the app names its exact files in Contents/Resources/licenses/SOURCE_CODE.txt.

Alan's voices

The voice models are not included in the download. RadioCheck fetches the one for your language during setup, from the official Piper voices repository, pinned to a fixed revision.

Voice	Language	Source
en_GB-alan-medium	English	Recorded by Alan Pope, and used here with his personal permission, kindly given in September 2026. Alan the race engineer is named after this voice, and (as it turns out) after a real person too. Thank you, Al.
es_ES-davefx-medium	Spanish	Recorded by the contributor known as davefx and released under CC0 (public domain) through the OHF Voice datasets. Thank you as well, whoever you are.

Speech recognition uses Whisper models (MIT), also downloaded on demand rather than bundled.

Libraries inside the app

All under permissive licences except certifi (MPL 2.0, a file-level weak copyleft), and all used unmodified. The complete list, with versions and licence texts, ships inside the app in Contents/Resources/licenses/THIRD_PARTY_NOTICES.txt.

Component	Licence	Used for
discord.py · discord-ext-voice-recv	MIT	Alan's voice in a Discord channel, and hearing you
PyNaCl	Apache 2.0	Discord voice encryption
opuslib	BSD 3-Clause	Opus audio for Discord
faster-whisper · CTranslate2	MIT	Speech recognition on your Mac
onnxruntime	MIT	Running the voice model (inside piper-worker only)
aiohttp	Apache 2.0	Discord's network connection
pycryptodome	BSD 2-Clause / public domain	Decrypting Gran Turismo telemetry
openai	Apache 2.0	Optional cloud voice features, with your own key
pydub	MIT	The radio effect on Alan's voice
pywebview	BSD 3-Clause	The app's own windows
websockets	BSD 3-Clause	Live telemetry to the HUD
NumPy	BSD 3-Clause	Telemetry and audio maths
sounddevice	MIT	Microphone input
huggingface-hub · tokenizers	Apache 2.0	Fetching the speech model
PyYAML	MIT	Reading the detection thresholds
python-dotenv	BSD 3-Clause	Reading your settings file
certifi	MPL 2.0	Certificates for secure connections
Python (with OpenSSL, SQLite)	PSF · Apache 2.0 · public domain	The language RadioCheck is written in
PyInstaller bootloader	GPL 2.0 with the bootloader exception · Apache 2.0	Starting the app

Typefaces

The app's screens use these typefaces, all under the SIL Open Font License 1.1 and used unmodified. After version 0.9.20 they ship inside the app, each with its licence text, in Contents/Resources/frontend/assets/fonts/; up to 0.9.20 they were loaded from Google Fonts.

Typeface	Authors	Used for
Inter	The Inter Project Authors	Text, labels and buttons
JetBrains Mono	The JetBrains Mono Project Authors	Times and numbers
Barlow · Barlow Condensed	The Barlow Project Authors	Headings, tags and the report card
IBM Plex Mono	IBM Corp. (Reserved Font Name "Plex")	Values in the first-run setup

Other credits

Car and circuit data is derived in part from the community-maintained GT7 info database. Gran Turismo, PlayStation and PSVR2 are trademarks of their respective owners; RadioCheck is an independent project and is not affiliated with Sony Interactive Entertainment or Polyphony Digital.