Audacity & Slate FG-X/VCC

[zabukowski]

Hi

I have rather specific situation here (Win 7 x64) which drives me crazy !!!

I've programmed my own VST host program. It works with all plugins as expected, only with Slate FG-X & VCC there is a misbehavior. Plugins load ok, but with the first processReplacing call, VU meters stop working, preset system on FG-X stop working, on/off buttons are dead etc. Again, ALL other plugins i've tried (many) work, including Slate's VTM. Just can't find the reason no matter what I do. Majority of hosts (cubendo etc.) on my machine work as expected, so I am sure i am doing something wrong in my code.

I've noticed that Audacity suffers from the same problem (Audacity 2.0.5). If for example FG-X is selected as effect on track and preview is started/stopped, all described symptoms are there. When preview is in progress, VU meters are dead, on/off buttons don't work etc. BEFORE actual preview buttons work, check it out. It looks Audacity approach to the VST plugins in the same way as my host, triggering this particular problem.

Please, can you check this behavior on your machine if possible.
If it doesn't work, please rename Audacity folder to "Audacity_SAM" and try again. Does it work now?

Thanks in advance for your help!
Zabukowski

[Gale Andrews]

Audacity doesn't have real-time effects, if that helps.

I don't think anyone here has iLok2, so no-one can test the plug-ins you mention.


Gale

[zabukowski]

Audacity doesn't have real-time effects, if that helps.

I don't think anyone here has iLok2, so no-one can test the plug-ins you mention.


Gale

I know it is not realtime, but shouldn't plugin meters react when preview is generated? At least they are with other plugins.
Strange thing is that plugin acts normal before preview. After preview, some buttons are not working anymore, presets are not accessible etc.

I hope someone around here will have a chance to check this out, i didn't know, iLok is so rare in Audacity community.

Thanks for help!
Zabukowski

[Gale Andrews]

I know it is not realtime, but shouldn't plugin meters react when preview is generated?

I've don't personally recall any plug-in with a live meter that responds to Audacity preview.

At least they are with other plugins.

Are you saying that meters in Slate VTM definitely respond to Audacity preview?

Strange thing is that plugin acts normal before preview. After preview, some buttons are not working anymore, presets are not accessible etc.

I hope someone around here will have a chance to check this out, i didn't know, iLok is so rare in Audacity community.

I think you misunderstand something. Audacity is free and everyone is a volunteer. We obviously prefer free software hence generally we don't buy proprietary commercial effects that require proprietary hardware activation. So no-one who reads this Forum has iLok2 (I think an Audacity developer may have an older iLok but he isn't frequently active in the project).

If you would like us to buy iLok2 please donate £40 GBP here http://audacityteam.org/donate/ with a note of what your donation is for.

I agree it's weird that a plug-in should fail after preview, but it could be a bug in the plug-in. Do Slate FG-X and VCC work in preview in Cubendo and other hosts?

Does your host operate live, that is you can record or play, twiddle the effect knobs and the audio changes?

Have you contacted Slate about the matter http://www.slatedigital.com/support/ ?


Gale

[zabukowski]

I've don't personally recall any plug-in with a live meter that responds to Audacity preview.

All plugins (except VCC/FG-X) including VTM react, when preview buffer is generated. When preview buffer is played, plugin GUI is not updated, but that is expected.

I agree it's weird that a plug-in should fail after preview, but it could be a bug in the plug-in. Do Slate FG-X and VCC work in preview in Cubendo and other hosts?

The same case, Cubendo doesn't update meters when previewing with problematic plugins - other plugins work there as well.

I think you misunderstand something. Audacity is free and everyone is a volunteer. We obviously prefer free software hence generally we don't buy proprietary commercial effects that require proprietary hardware activation. So no-one who reads this Forum has iLok2 (I think an Audacity developer may have an older iLok but he isn't frequently active in the project).
If you would like us to buy iLok2 please donate £40 GBP here http://audacityteam.org/donate/ with a note of what your donation is for.

I know what Audacity is about and I am impressed and thankful for your excellent job. I didn't say you must help me, just asked if you maybe could help me, if possible. It is perfectly possible for someone to write free & commercial software and at the same time do payed music production using commercial sw with iLok for example. This is very close to what i do

Does your host operate live, that is you can record or play, twiddle the effect knobs and the audio changes?

It plays & process files in realtime + as you said, twiddle the effect knobs and the audio changes.

Have you contacted Slate about the matter http://www.slatedigital.com/support/ ?

I did contact Fabrice directly, but i didn't get any useful answers More generic stuff like "plugins will be changed/rebuilt/updated, problems will probably be gone then". I'll try again, now i've found out some more about it.

IMPORTANT I've discovered something new.

If VCC/FG-X processReplacing is called from the main Portaudio callback function, then they work as expected. Looks to me like timing of processReplacing is very important to them. If processReplacing is called from any other place of my program (processing fx in other synchronized thread, for example), they don't work. Again, all other plugins work :/

Thanks!
Zabukowski

[zabukowski]

I can confirm that moving processReplacing to main "audio callback" function solves mentioned problems. Previously it was called from a separate, synchronized thread.

Looks like processing not being 100% bound to audio interrupt is causing anomalies with GUI of these plugins.

Good to know before implementing real-time processing, as maybe there are some non-ilok plugins with the same problems out there.

Thanks for your help!
Zabukowski

[Gale Andrews]

Thanks for the follow-up and explanation, zabukowski. I'll make a note of this on our Wiki page about VST plug-ins.


Gale