Plugin can't route to more than two channels on a track

Hi there. We are working on an NDI plugin, and I’d like to get it to work with Ardour/Mixbus. So far it does work as expected in Reaper.

There are two problems:

  1. Even though the track is 12 channels in Ardour, I can’t list the other channels to send my audio to. I can do that in Reaper.
  2. With the Sender version of the same plugin, I am supposed to write in the box, but Ardour/Mixbus won’t allow me to type, but will take all keystrokes as shortcuts on the main UI.

I am attaching two short videos showing the behavior in Ardour/Mixbus and in Reaper.

Where could I start looking for this bug? This was built using JUCE.



Mixbus Can’t type in plugin


I cannot watch videos here (low bandwidth link), but for (2), top-left in every plugin UI window is a “keyboard” icon. That allows to disable global shortcuts and focus the plugin’s own GUI for key-entry.

As for (1), that is unusual. On a 12 channel track Ardour provides 12 I/Os to every plugin and may also replicate the plugin as necessary. You could also use a stereo track and pick variable-i/o (as opposed to strict-i/o this will allow a plugin to add or remove ports).

One explanation would be that you have created VST3 plugin with optional busses instead of a 12 channel wide main bus.

For the time being Ardour only supports one main-bus and one optional sidechain bus for VST3. – LV2, VST2, AU do not have this limitation.

Thanks Robin. I confirm that issue 2 related to typing works as you suggested after clicking on the keyboard.

I have an AU version available on my system which is found by Ableton Live, Mainstage and Studio One on my mac. Why would Ardour not pick it up?



Have you scanned for new plugins since installing it?

Menu > Window > Plugin Manager – or Preferences > Plugins > AU

All right, so the AU version of the plugin works fine up to 8 channels. After adding the 9th audio in i/o I get the following when trying to add the plugin:


Any clue of what could be the limiting factor here? I am using Flexible I/O.

This topic was automatically closed 28 days after the last reply. New replies are no longer allowed.