NDI Tools - Free Audio

An innovation on the part of NDI Tools which is very practical and therefore deserves a small mention. It would be nice if the manufacturers of NDI converters would also release converters soon which make NDI to e.g. Dante. With this small tool. you can easily make such an interface.

NDI Free Audio is a command line utility which can be found on the homepage at the NDI Tools as a separate download. It runs on all platforms and allows any device with a physical sound card to be used as an audio I/O interface for audio over NDI.
https://ndi.video/tools/free-audio/

So you can set up a MiniPC or Raspery Pi as an audio I/O interface to tap audio from an NDI signal flow. In this way, for example, a PC with a Dante AVIO dongle can convert the NDI audio to Dante, which can then be used on a mixer, AMP or a DSP. Or you pick it up at the analog output from the PC.

If you open the NDIFreeAudio.exe via the start menu, it shows you all available physical inputs/outputs on the computer. Based on this and the desired NDI signal, you then construct your startup parameters which you enter via a batch file or the task scheduler of the exe file.

Using the Task Scheduler, the NDIFReeAudio.exe (Windows) can be triggered very easily with the required parameters at the startup.

For a small test, best the test patterns from the NDI Tools open, generate a 1 kHz ton and tap this NDI signal via the desired output interface. In my case, the argument/command looks like this:
output «Speakers (Realtek(R) Audio)» [default]» -output name «myPCName (Test Pattern)»

Underground -output i have selected my notebook speaker according to the indication in FreeAudio.exe (see above). Underground -output name i refer to the NDI source whose audio I want to deembeden. To see the NDI sources in the network, it is best to use the Studio Monitor from the NDI Tools open. There you will find the address for your NDI stream that you want to tap.


Enter this in the task from the scheduler under argument.
As soon as the task triggers the exe, the audio from the NDI signal «Test Pattern» is output by my PC via the local sound card.

Alternatively, you can also use the command with -output default -output name «myPCName (Test Pattern)» build up. Then simply the default set sound card is always used as a playout way.

Of course, the tool also allows you to send audio in the other direction or both and has other parameters, e.g. Gain, which you can set. More detailed information can be found in the instruction in the PDF which is supplied during the installation.

I hope this article helps one or the other. Have fun and success while trying