SDR# / DCS decoder plug-in
Visual Studio 2019. NET C#
dotPeek https://www.jetbrains.com/decompiler/download/#section=web-installer

Reverse engineering SDR# DCS tone decoder plug-in.
Modifying for decoding other digital tone codes/protocols than DCS seems possible with some work, e.g. POCSAG raw data.

decoder1.jpg
https://i.ibb.co/sHhM7Wp/decoder1.jpg

decoder2.jpg
https://i.ibb.co/HgN8470/decoder2.jpg

decoder3.jpg
https://i.ibb.co/WD9c6CX/decoder3.jpg

... also dcsdecoderpanel (UI) mods needed for showing received data ...