--- 12 August 2016 ---

The STEAK Project

In the STEAK project, we are implementing a telephone conferencing system. In difference to widely available system, this system will be providing 3D audio when headphones are used.

For more details, please check out:

  1. The Project,
  2. The Theory of Spatial Rendering,
  3. The Implementation, and
  4. The Demo.


The project is finished while the modifications are going to be integrated into Asterisk.

News (RSS Feed)

: The End

On the 25th February 2017, the last commit from the STEAK project was merged into Asterisk upstream (master) and should be included in the upcoming release of Asterisk 15.

That’s it - the STEAK project is now finished.

Just one thing is still (and will probably remain) missing: by default Asterisk does not provide an audio codec that supports multi-channel audio transmission. For the STEAK project, we extended the open-source Asterisk driver for OPUS.

This driver can be found here.

To enable 3D-Audio for Asterisk using our OPUS driver:

git clone http://gerrit.asterisk.org/asterisk
git clone  https://github.com/SteakConferencing/asterisk-opus

cp asterisk-opus/codec/* asterisk/codec


make menuconfig
#Enable "Bridging modules"/binaural_rendering_in_bridge_softmix
#Enable "Codec Translators"/codec_opus_open_source
#Disable "Channel Drivers"/chan_sip


Tested with Asterisk (comit-id 00d1c7ddd28557aa845c3522956852a60310df96).

The end.

: Opus For Asterisk

The cleanup of our stereo-capable Opus module for Asterisk is finished. It is based upon the open source module maintained by Alexander Traud. The code is available here.

: Demo Retired

On 1th November 2016 the demo system was retired. The DNS entry demo.steakconferencing.de now maps to

For anybody to recreate the setup, the required configuration files (incl. SSL certificates) are now on Github.

: 141th Convention Of The Audio Engineering Society

Today the STEAK project was presented at the 141th convention of the Audio Engineering Society. The paper (and its latex code) is on Github Code/PDF.

: Astridevcon 2016

The STEAK project was presented at the annual developer conference (AstriDevCon 2016) in Phoenix, AZ. The community was excited and provided valuable feedback. We are not going to integrate the necessary changes into the submitted patch set and are now one step closer to upstream.

: Code Submitted To Upstream

Code cleanup finished and code submitted upstream.

Issue request: ASTERISK-26292.

Links to threads on mailing list:


: Demo Online

A demo of is now available.

For more details see The Demo

: Source Code Release Asterisk

The enhanced source code (STEAK-enabled so to say) of Asterisk is released: here.

: Code of the WebRTC-client released

The source code of the WebRTC-client is know availble: here.

Only runs in Google Chrome or Chromium.

: Website Online

The website of the STEAK project is now online.