Question: Mumble Plugin support?

[hbeni]

Hi,
I‘m very interested about this lib; for integrating the fgcom-mumble plugin directly into flightgear flight simulator.

Is it planned to make an interface to load a compiled plugin into the lib, so it calls the hooks?

[davidebeatrici]

Hi,

This library can be used to implement your own client/server. The plugin API is part of the official client.

If you need full access to the Mumble protocol, libmumble is the way to go. Basically, you would be loading the library in your application rather than the opposite.

[Krzmbrzl]

That is to say that currently there are no plans to integrate Mumble's plugin framework into this library. It just doesn't seem like a good fit as this library is meant to implement the low-level of handling the Mumble protocol and client plugins are quite high level and not all downstream users of this library will even want plugin support, I guess 🤔

[hbeni]

Thanks for the quick answer!

I understand, but what I still wonder: Does the lib provide some means for example to modify the incoming audio data?
And will it provide a method to send/receive plugin data?

Merry Christmas ☺️🎄

[davidebeatrici]

Yes, absolutely. Audio can be decoded/encoded using Opus::Decoder and Opus::Encoder.

libmumble/include/mumble/Message.hpp

Lines 102 to 123 in 4c1b920

	MUMBLE_MESSAGE_DECL(Audio) {
	enum : uint8_t { Unknown, ClientToServer, ServerToClient } direction;
	union {
	// Client to server.
	uint32_t target = UINT32_MAX;
	// Server to client.
	uint32_t context;
	};
	std::optional< uint32_t > senderSession = {};
	uint64_t frameNumber = 0;
	std::vector< std::byte > opusData = {};
	std::vector< float > positionalData = {};
	float volumeAdjustment = 0.f;
	bool isTerminator = false;
	MUMBLE_MESSAGE_COMMON(Audio)
	};

As for sending/receiving plugin data:

libmumble/include/mumble/Message.hpp

Lines 434 to 435 in 4c1b920

	std::vector< std::byte > pluginContext = {};
	std::string pluginIdentity = {};

libmumble/include/mumble/Message.hpp

Lines 680 to 687 in 4c1b920

	MUMBLE_MESSAGE_DECL(PluginDataTransmission) {
	uint32_t senderSession = UINT32_MAX;
	std::vector< uint32_t > receiverSessions = {};
	std::vector< std::byte > data = {};
	std::string dataID = {};
	MUMBLE_MESSAGE_COMMON(PluginDataTransmission)
	};

These are all messages you can receive and interpret or construct and send through the library.

Merry Christmas too!

[hbeni]

Thank you very much!

How stable is libmumble? Is it a good point in time to start integrating?

And are there examples on how to integrate the lib build/linking to the main application?

[Krzmbrzl]

It should work but the API is not yet stable. It may be changed without notice or regards for backwards compatibility.

[davidebeatrici]

@Krzmbrzl I deleted your duplicate comment.

@hbeni Examples can currently be found in the examples directory.

[hbeni]

Thanks!

what would be the best way to integrate libmumble into an cmake build setup?

[davidebeatrici]

For the time being I would add it as a Git submodule.

In your CMake project you then call add_subdirectory() and link your target to the library using target_link_libraries().

[Krzmbrzl]

Use FetchContent. That creates fewer hassles than using a submodule in my experience 👀

[hbeni]

Ah okay.

and one last question (I hope): how does the lib work overall?
I learned that it will create a threadpool for the tcp/udp data exchange, but am I correct in understanding that

• for sending audio data, I will just call a lib function and hand over the packets?
• For receiving audio, the lib will call some callback function which gets the audio data handed over?

[davidebeatrici]

Correct.