Open Source Components

Effective: September 16, 2026
Current compliance release: SPECTER SDR 1.7.41
Support: support@specter-imaging.com

Source and notices

Every SPECTER SDR installer places third-party notices, license texts, and a versioned Open Source Components archive in the installed resources/legal directory. The same source archive and its SHA-256 file are attached to the corresponding GitHub release.

DOWNLOAD 1.7.41 SOURCE ARCHIVE

SPECTER SDR Receiver Sidecar

The receiver sidecar is licensed under GPL-3.0-or-later. Its preferred source, build scripts, PyInstaller specification, patched dependency source, and exact dependency archives are included. The sidecar is a separate local process that exchanges newline-delimited JSON and binary receiver frames with the proprietary Electron interface. You may rebuild and replace it under the GPL.

Replaceable LGPL libraries

FFmpeg, libusb, SoapyBladeRF, and libbladeRF are distributed as ordinary files outside the proprietary application archive. The receiver sidecar is installed as a directory with its own runtime files. Compatible modified builds may replace them. SPECTER uses an LGPL shared FFmpeg build with the Windows Media Foundation h264_mf encoder. It does not ship libx264 or libx265.

Optional decoder engines

rtl_433, SatDump, AIS-catcher, DSD-FME, and other optional engines are not bundled into the installer. Decoder Lab identifies the publisher, project, source, and license, then downloads a hash-pinned upstream package only after your approval. Each engine remains governed by its own license.

Written source offer

If the release archive becomes unavailable, SPECTER will provide a durable digital copy of the corresponding GPL and LGPL source for no more than the reasonable cost of distribution. This offer remains valid to anyone possessing the corresponding object code for at least three years after the last distribution of that object code.