Hi Jules,
Further to this thread from 2008 http://www.rawmaterialsoftware.com/viewtopic.php?f=8&t=3421 it seems that Juce plugins which don’t support a 2-in/2-out channel config still fail AU Validation with error kAudioUnitErr_FormatNotSupported (-10868). What’s worse is that Reaper refuses point blank to use one of the supported configs.
Can I suggest that something like the following is added at the end of the JuceAU constructor?
[code] CreateElements();
CAStreamBasicDescription streamDescription;
streamDescription.mSampleRate = GetSampleRate();
streamDescription.SetCanonical(channelConfigs[0][0], false);
Inputs.GetIOElement(0)->SetStreamFormat(streamDescription);
streamDescription.SetCanonical(channelConfigs[0][1], false);
Outputs.GetIOElement(0)->SetStreamFormat(streamDescription);[/code]
This was sufficient for my needs, but you’ll probably want to add a special case for #ifdef JucePlugin_IsSynth and maybe default to {2,2} if it’s available instead of the first one on the list.
Rupert
Reference: http://www.soundsorange.net/resources/developing-audio-units-for-mac-osx/multi-channel-aus/