Opus compression audio for Godot

This is a low level operation of the opus library based on https://github.com/RevoluPowered/one-voip-godot-4/ with a VoIP-over-MQTT demo project.

It can also integrate with OVRLipSync if you download it and are not on Linux.

Build instructions:

Nixos

The build system is defined by the flake.nix file

• makes a result directory that needs to be copied into addons

nix build cp result/addons/twovoip/*so addons/twovoip

• android version:

nix build .#android cp result/addons/twovoip/*so addons/twovoip

• Windows version: (incomplete) Start the project in Visual Studio and let it clone and compile the opus project

python -m SCons

Make sure addons/twovoip/twovoip.gdextension point to these files:

Otherwise by hand when developing

Since we've not got submodules here we need to first clone Opus and godot-cpp modules before building them

> git clone git@github.com:goatchurchprime/two-voip-godot-4.git
> cd two-voip-godot-4
> git clone git@github.com:godotengine/godot-cpp.git
> cd godot-cpp
> git checkout 48afa82f29354668c12cffaf6a2474dabfd395ed
> cd ..
> git clone git@github.com:xiph/opus.git
> cd opus
> git checkout c85499757c148fede8604cffa12454206b6138ba

On Linux:
> cmake -Bbuild -DCMAKE_POSITION_INDEPENDENT_CODE=ON
> cd build
> make
> cd ../..
> scons  (or python -m SCons on Windows)

On Windows:
Use Visual Studio 2022 Community Edition with CMake option to open opus
directory and convert cmake script to sln and then compile.
> cd ../..
> scons  (or python -m SCons on Windows)

On Mac: See the instructions on the one-voip here: https://github.com/RevoluPowered/one-voip-godot-4/?tab=readme-ov-file#mac

With OVRLipSync

This is a highly speculative component that takes advantage of the chunking feature in the OpusChunked effect, but which is currently closed source. There is no Linux version. See godotengine/godot-proposals#9718

Download the OVRLipSync libraries from https://developer.oculus.com/documentation/native/audio-ovrlipsync-native/ and unzip into top level as OVRLipSyncNative directory in this project. There is a stub include file for Linux that allows this GDExtension to compile and work without this library.

On Windows you may need to copy the OVRLipSyncNative/Lib/Win64/OVRLipSync.dll file to the same directory as your GodotEngine.exe so that it finds and links it.