FFmpeg and media tools used by Nathan Tech

Several Nathan Tech applications use a shared set of media and runtime tools for tasks such as reading media files, converting audio and video, inspecting file information and generating audio fingerprints.

This page explains which versions we use, why some of them are built specifically for 32-bit Windows, and where to obtain the relevant licence notices and corresponding source/build material.

FFmpeg and FFprobe

FFmpeg is an open-source multimedia framework used for reading, converting, encoding and processing audio and video. FFprobe is its companion utility for inspecting media files and streams.

Nathan Tech currently uses a custom build of FFmpeg 8.1.2 and its matching FFprobe utility.

Our FFmpeg and FFprobe executables are built for 32-bit Windows x86. A number of Nathan Tech applications are still distributed as 32-bit Windows applications, so keeping these media tools available in a genuine x86 build gives us a predictable, reusable runtime across those projects.

The build includes the functionality required by our software, including common audio and video formats, MP3, Opus and Vorbis support, DirectShow input, networking, filtering, scaling and media inspection.

Our build is deliberately configured to remain under FFmpeg's LGPL version 2.1 or later licensing model. We do not enable FFmpeg's optional GPL, GPLv3 or non-free build modes, and we do not enable GPL codec libraries such as x264 or x265 in this build.

Chromaprint and fpcalc

Chromaprint is an audio fingerprinting library. Its command-line tool, fpcalc, is used to calculate fingerprints from audio files.

Nathan Tech currently distributes a custom 32-bit Windows x86 build of fpcalc 1.6.1. It uses FFmpeg for media decoding and resampling and uses the bundled KissFFT implementation for its fingerprinting FFT backend.

Deno

Some Nathan Tech software also uses Deno as a separately launched runtime.

Deno is the one intentional architecture exception in this shared tools set. Modern Deno does not provide a 32-bit Windows x86 build, so our Deno executable is 64-bit Windows x86-64 and is only launched as a separate process. It is not loaded into our 32-bit applications as a DLL.

Where these tools are used

These tools are shared between several Nathan Tech projects, including applications such as Calliope and Theia, and may also be used by future media-related software.

Each Nathan Tech application uses only the components it needs. The applications themselves do not directly link against the FFmpeg DLL API; FFmpeg, FFprobe, fpcalc and Deno are launched as separate executable tools where required.

Licensing and corresponding source

FFmpeg, Chromaprint and the other open-source components used in these builds are distributed under their respective licences. Deno is distributed under the MIT licence.

To make the licensing and build history straightforward to inspect, Nathan Tech makes available the licence notices, exact build information, source archives and build/relink material corresponding to the media-tools versions we distribute.

Download the corresponding source, build information and licence material.

The source package above corresponds to the builds described on this page. When Nathan Tech updates the media-tools bundle, this page and the corresponding source package will be updated as well.

Current version summary

• FFmpeg: 8.1.2 - Windows x86 / 32-bit
• FFprobe: 8.1.2 - Windows x86 / 32-bit
• Chromaprint fpcalc: 1.6.1 - Windows x86 / 32-bit
• Deno: 2.8.1 - Windows x86-64 / 64-bit, separate-process runtime

If you have a question about these builds, licensing or the corresponding source material, please use the Nathan Tech contact page.