Broken AAX automation via Artist Control

I received the following bug report from our distributor:

"Using the Artist Control controller to adjust parameters, continuous parameters are set to minimum value once the respective knob is touched, and remain minimum regardless of the knob setting.

Discrete parameters (On/Off or multi-state) are controlled fine via control surface.

Tested with Artist Control (latest firmware), EUControl 3.3, Pro Tools 12.1, OS X 10.10.4 Yosemite....

I'm not sure, but it seems that this issue is related to JUCE, as we have seen other JUCE products where this issue appears. Can you investigate if this is a known issue for JUCE and if there is anything you can do about?"

I imagine that this is due to the fact that JUCE doesn't currently support EUControl. However, parameters are definitely responding, albeit in a broken manner. It's unfortunate that this occurs with such a boutique controller, but apparently a significant enough portion of our userbase uses one.

This problem is also visible with the Avid S6 control surface emulator.

It looks like reducing the number of steps of a continuous parameter solves that. The AAX wrapper will still declare is as continuous while this number of steps is greater than 1000.

But I didn't really understand why it works...

I've installed the surface emulator on our dev systems and waiting to hear from Avid to activate the emulator. I'll try to reproduce this bug once I get the emulator working.  Thank you for reporting!

There is no specific activation for the emulator, you just need a running ProTools Dev.

I can confirm that Manu's fix worked for us. On plug-in startup, we check all of our parameters using getNumSteps. If getNumSteps returns >256, we set it to 256. We chose 256, as that was a number given on the AAX Dev forum as a useful upper-limit for numSteps.

Any official news on this matter ?

Bumping this. Our strategy of reducing the number of steps to 256 per parameter was causing a lot of issues, so we had to disable it.

@trickyflemming one thing we’ve discovered the hard way… ;(
Don’t change number of steps for released products for the same parameter. this will cause PT to parse the automation data differently breaking compatibility in a very nasty way.

Thanks for the heads up! We’ve only disabled it on our upcoming products for now. We have to come up with a good fix for Artist Control that doesn’t break touch automation.

Essentially, changing the number of steps to 256 caused Artist Control to work properly, but broke touch automation due to rounding errors between the processor and the Slider class. We tried setting the sliders’ intervals to 1.0/numSteps, and that only partially fixed it. We’re trying to figure out if we can get both working properly, but touch automation is higher priority.

Hi All!
Are there any news about this bug?

is this issue fixed in newer juce version and is it safe for older (already released) plugins to migrate to juce 5?
I mean - will there be any problems with AAX automation recorded with older plugins?

I think it is but you really can’t be sure without testing it yourself.