OP25j

=== GNURadio patches ===
The demodulator program described below makes use of a number of non-standard extensions to the [http://www.gnuradio.org GNURadio framework]. To use GNURadio the source code distribution must be patched and then built and installed on the target platform.

=== Demodulator ===
The most basic part of the software is the [DemodulatorPage P25 demodulator program]. This takes a signal source as its input and produces a stream of messages as its output. The message streams can be captured to file or forwarded to the TAP device.

=== Sniffer ===
A modified version of the [http://www.wireshark.org WireShark] packet sniffer is used to inspect the contents of the message stream. Custom dissectors pick apart the P25 messages and allow the inspection of individual data items.