Mumble (software)

Mumble

Main view of Mumble
Original author(s)	Thorvald Natvig
Developer(s)	Various
Initial release	2005
Stable release	1.2.5 / February 5, 2014 (2014-02-05)
Written in	C++
Operating system	Linux, OS X, Microsoft Windows, iOS, Android
Platform	Qt
Type	VoIP client and server
License	New BSD license
Website	mumble.sourceforge.net

Mumble is a voice over IP (VoIP) application primarily designed for use by gamers, similar to programs such as TeamSpeak and Ventrilo.^[1]

Mumble uses a client–server architecture which allows users to talk to each other via the same server.^[2] It has a very simple administrative interface and features high sound quality and low latency. All communication is encrypted to ensure user privacy.^[3]

Mumble is free and open-source software, is cross-platform, and is released under the terms of the new BSD license.

Channel hierarchy

A Mumble server (called Murmur) has a root channel and a hierarchical tree of channels beneath it. Users can temporarily connect channels to create larger virtual channels. This is useful during larger events where a small group of users may be chatting in a channel, but are linked to a common channel with other users to hear announcements. It also matches team-based first-person shooter (FPS) games. Each channel has an associated set of groups and access control lists which control user permissions. The system supports many usage scenarios, at the cost of added configuration complexity.^[4]

Sound quality

Mumble uses Speex not only as a voice codec, but also for noise reduction and automatic gain control. Version 1.2 added support for CELT.^[3] Mumble is optimized for low latency, resulting in faster communication. Mumble incorporates echo cancellation, which permits the use of speakers as well as headphones. With some games, like Battlefield and Call of Duty on Windows, a plugin lets you hear the positional audio of other players.^[5] Mumble version 1.2.4 added support for Opus; the codec that succeeds both Speex and CELT.

Overlay

There is an integrated overlay for use in games.^[3] The overlay shows who is talking and what linked channel they are in. As of version 1.0, users could upload avatars to represent themselves in the overlay, creating a more personalized experience. As of version 1.2, the overlay works with most Direct3D 9/10 and OpenGL games on Windows and has OpenGL support for Linux and Mac OS X.^[6] DirectX 11 game support is planned.^[7]

Positional audio

For certain games, Mumble modifies the audio to position other players' voices according to their relative position in the game.^[3] This not only includes giving a sense of direction, but also of distance.

To realise this, Mumble sends each player's in-game position to players in the same game with every audio packet. Mumble can gather the information needed to do this in two ways: it either reads the needed information directly out of the memory of the game or the games provide it themselves via the so-called link plugin interface.

The link plugin provides games with a way to expose the information needed for positional audio themselves by including a small piece of source code provided by the Mumble project.^[8] Several high-profile games have implemented this functionality including many of Valve's Source Engine based games (Team Fortress 2, Day of Defeat: Source, Counter-Strike: Source, Half-Life 2: Deathmatch) and Guild Wars 2.^[9]

Competition

Mainstream software suites that directly compete with Mumble include Ventrilo and TeamSpeak. GameVox is a new voice product in Beta built from Mumble.

Server integration

Mumble fits into existing technological and social structures. As such, the server is fully remote controllable over Ice.^[10] User channels as well as virtual server instances can be manipulated. The project provides a number of sample scripts illustrating the abilities of the interface^[11] as well as prefabricated scripts offering features like authenticating users using an existing phpBB or Simple Machines Forum database.^[12] The murmur server uses port 64738 TCP and UDP by default.

An alternative minimalist implementation of the mumble-server (Murmur) is called uMurmur.^[13] It is intended for installation on embedded devices with limited resources, such as, for example, residential gateways running OpenWrt.^[14]

Server hosting

Like many other VoIP clients, Mumble servers can be both rented or hosted locally. Hosting a Mumble server locally is as easy as downloading Murmur (included as an option in the Mumble installer) and launching it. Configuring the server is as simple as editing the configuration file. The configuration file holds information for the server's name, user authentication, audio quality restrictions, and port. Finding the configuration file can be difficult, because each OS places it in a different area. On Windows, it is located in the root directory of your Mumble folder, named "murmur.ini".

Administrating the server from within requires a user to be given administrator rights, or can also be done by logging into the SuperUser account. Administrators within the server can add or edit rooms, manage users, and view the server's information. Setting a password for the SuperUser account can also be difficult, as the process differs across operating systems much like editing the Murmur configuration.

See also

• Comparison of VoIP software

References

External links

• Official website
• Mumble (software) on SourceForge.net
• uMurmur Minimalistic Mumble server daemon written in C for embedded hardware