Is there a way to select my own selection of audio-busses to a SRT stream?

I want to stream 4 multichannel SRT streams, with 4 to 8 audio-channels.
It ís possible to stream 8 audio-channels to only one SRT stream, and only with Bus MABC.
But I want to stream 4 video inputs with 8 audio-channels to 4 Multichannel SRT streams.

Sending the video input directly to the output is easy, but audio kan only go over the vMix busses. I can not send the audio channels from the input directly to the SRT output. Please add this feature, or tell me how to configure this.

There is a maximum of 8 Stereo audio-busses. MABCDEFG, so there are 16 mono audio-channels. So sending 8 audio channels to 4 outputs is impossible.

So the second option is to send only 4 audio-channels to every SRT stream. But it is not possible to choose other audio-bus combinations, than the preset of vMix.
For example I would like combinations of MA, BC, DE and FG. But I can not choose by own selections of audio-busses.

Secondly, VLC player is not receiving multiple audio channels (jet). It can play multiple audio-channels from a file, but not from a srt stream.

Best scenario for me is to send the Input directly to the srt output.

Am I making any sense?

Sort of. :-)

I understand the setup like this:

1. vMix has 8 audio busses internally. That matches nicely with 8 audio signals a SDI stream can carry.
2. Audio inputs are routed to one or several audio busses or not, that's it.
2. On the output side (external, streaming, SRT, recording) you can only use audio bus signals.
2. There is no internal audio matrix within vMix where you can do advanced audio routings like you are asking for.
3. This means, you can only use bus signals for your output.

As a workaround, use an external audio interface with a routing matrix like RME or MOTU (1284 my favourite). Do the audio routing there (also dynamically, if needed) and feed the routing destination as input into vMix, there on a bus and from there to your output streams.

However, you can not go over the max amount of 8 busses within vMix. In this case you need external encoding solutions which would take the video from vMix and the audio from the audio interface. However, beware of A/V delays on such a setup.

If you are looking for software, maybe there is something at SRT Miniserver which can help.

A few clarifications about SRT:

1. SRT is a "data pipe", not a "video transport protocol" like NDI. You can use it with any data, audio only, files, cat pictures - as long as sender and receiver software agree on handling the content. Of yourse, SRT was made to carry audio and video data over the public Internet.
2. In vMix context this pipe is used with H.264 encoded video mostly.
3. In H.264 the audio is carried with the AAC codec.
4. The AAC codec supports multichannel audio, quite a lot of channels:
5. Again, sender and receiver need to be able to handle AAC multichannel streams.

Please let us know how your solution worked out.

Good luck,

Christian