Plugin failing to load in mono when requiring input/output channel layout to match

Audio Plugins
1

I'm working on a compressor plugin that utilizes a sidechain. I followed the Multibus guide and used NoiseGate as an example. I updated to the latest tip yesterday, got everything working in my plugin. I then decided I wanted to force the input channel count to match the output channel count (stereo->stereo, or mono->mono) so I copied the following lines from NoiseGate:

if (! AudioProcessor::setPreferredBusArrangement (! isInputBus, busIndex, preferred))

            return false;

Opened Logic, reset and rescanned the plugin. Loading it in stereo worked fine. But when I tried to load it on a mono track I got the following error message from Logic:

Failed to load Audio Unit “AGCompressor”, please contact the manufacturer for an updated version or further assistance.​

Removing that line of code removes the error and allows it to load in mono. But it also makes the mono->stereo option available which I'm trying to get rid of.

To make sure it wasn't an issue in my code, I rebuilt NoiseGate using the latest tip, opened it in Logic, rescanned it, loaded it on a mono track, and got the same error.

Mac 10.11, Logic X

2

Any ideas?

3

So I updated to 4.2 and rebuilt the Noise gate. I noticed that line of code was slightly changed to:

 if (isMainBus && ! AudioProcessor::setPreferredBusArrangement (! isInputBus, busIndex, preferred))
            return false;

But now it no longer forces the input and output to have the same number of channels. Logic now allows a Mono->Stereo option. Is this a bug, or is this feature just no longer available?

4

Any updates on this?