AudioUnitPluginFormat::setParameter Notifies Host


#1

Hi all, I’m doing some work on modulating plugin parameters and for this I need to know when a parameter has changed from the user actually moving a plugin’s parameter (i.e. the parameter change comes from the plugin).

This works fine for VST & VST3, however in the AU implementation setParameter calls sendParameterChangeEvent. This in turn broadcasts an async parameter change notification telling us that the plugin has changed it’s value. This means that when I set the parameter from a modulation, I get a callback in the future telling me the plugin has changed the parameter which I then use to set the baseline of the modulation which results in a feedback loop and the parameter tending in the direction of modulation.

I don’t think that this sendParameterChangeEvent should be present. I think this should only be called from the plugin i.e. when an equivalent of setParameterNotifyingHost is called.

Removing this seems to keep everything function correctly but also enables me to add my modulations. Can anyone think of anything else this might screw up if removed?


#2

Gentle bump now ADC has finished :wink: