Parameter automation, AudioProcessorValueTreeState, and Live

Are both AU and VST2 affected?


I’ve just installed a plugin that I built yesterday before pulling the 5.3.0 commit on develop - probably a 5.2.1 develop from a week or so ago and the problem exists there too, so this problem is somewhere between them.

I’m wondering if this got broken a few weeks ago when all those parameter changes were made?

broken by commit:

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Any updates on this?

Thank you

Hi @t0m - any eta on this or are we better heading back to 5.2.1 for now? thx

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I had the same issue in FL studio.
My workaround is to comment out the audioProcessorParameterChanged callbacks in AudioProcessorParameter::sendValueChangedMessageToListeners in file modules\juce_audio_processors\processors\juce_AudioProcessor.cpp (line 1441):

void AudioProcessorParameter::sendValueChangedMessageToListeners (float newValue)
    ScopedLock lock (listenerLock);

    for (int i = listeners.size(); --i >= 0;)
        if (auto* l = listeners [i])
            l->parameterValueChanged (getParameterIndex(), newValue);

    // audioProcessorParameterChanged callbacks will shortly be deprecated and
    // this code will be removed.
    for (int i = processor->listeners.size(); --i >= 0;)
        if (auto* l = processor->listeners[i])
            l->audioProcessorParameterChanged (processor, getParameterIndex(), newValue);

I tested VST2 only

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Would be great to see a fix soon. The current release is unusable for plug-in developers because of this bug and i want to use the great new 5.3 features :slight_smile:

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It’s been 7 days since last update - v strange!

Hey sorry, @t0m is on holidays and this is in his domain. He’s back on Monday.

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Fixed here:

Please give it a test. If all is well I’ll cherry pick the change to the master branch too.


thx - will check in the next hour or so and report back

Live on Windows is looking good now, thx. Not around Mac currently so can’t test AU. prob in another hour or so

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I’ve been waiting on this one as well; just built my plugin against the latest on develop, a632b57e7, looks good here too. Tested VST & AU in Live 10.0.1 on OS X 10.13.


confirmed all is good on OSX too. thx

Just curious, has AAX the same problem?

The same issue has already been addressed in the AAX, AUv3 and VST3 wrappers

Amazing, thank you.

Looks good @t0m; thank you very much!

I’ve found a new way to resurrect this issue. In a pretty simple test the orange light of doom illuminates whenever I put in a call to updateHostDisplay, such as I may do when a parameter name is updated, which seems like a strange reason to knock out automation.