freedv-backend

This repository contains a series of static libraries used by other FreeDV repositories (such as freedv-integrations) to support various functions:

1. RADE encode and decode.
2. Audio processing (e.g. resampling, AGC and RNNoise, among other actions).
3. FreeDV Reporter/PSK Reporter handling (TCP/IP, callsign encoding/decoding in RADE transmissions)

This is intended to be used as a Git submodule, i.e.

project/src$ git submodule add https://github.com/freedv/freedv-backend backend
...

# inside src/CMakeLists.txt
add_subdirectory(backend)

with required libraries linked in as needed.

Compiling standalone

This project can be compiled standalone by running cmake:

mkdir build
cd build
cmake ..
make

To enable unit tests, you can pass -DBUILD_BACKEND_UNITTESTS=1 to cmake:

cmake -DBUILD_BACKEND_UNITTESTS=1 ..
make
ctest -V

It's highly recommended to also set up a Python venv so that the "loss" tests can be executed (see RADE README):

python3 -m venv rade-venv
. ./rade-venv/bin/activate
pip install torch matplotlib
mkdir build
cd build
cmake -DRADAE_PYTHON_EXECUTABLE=$(pwd)/../rade-venv/bin/python3 -DBUILD_BACKEND_UNITTESTS=1 ..
make
ctest -V

Tests take some time. A good result ends like this:

100% tests passed, 0 tests failed out of 10

Total Test time (real) = 198.79 sec

TLS support (mainly for FreeDV Reporter) is enabled by default, but can be disabled (i.e. for platforms that can't do TLS) by passing -DDISABLE_TLS_SUPPORT=1 to cmake. Additionally, LibreSSL can be statically linked instead of the system's copy of OpenSSL by passing in -DUSE_STATIC_LIBRESSL=1.

Getting Support

Please create a GitHub issue if you find a problem with this repository.