VST processBlock


there is one thing I don’t understand about the processBlock method. I do nothing in it, and when I drag my vst in an audio track in Ableton Live, I still hear the input stream. Isn’t that supposed to block the input stream if I don’t fill the output buffers in the processBlock method?


Read the comments for processBlock.

If you do nothing to the output buffer when accumulateOutput is true, then of course you’ll just hear the input. If you do nothing when accumulateOutput is flase, you risk blowing your speakers out with white noise.

ok I get it, thanx. But how is set the variable “accumulateOutput”? I’m just curious, and I didn’t see any explanation about that.

That’s up to the host.

Let me see if I understand this.

If I instantiate this plugin as a “send effect” in cubase for example, then accumulateOutput will be active? As an insert on a specific track, accumulateOutput will be low. Is that right?

I’m just guessing here, I know that when I was just using the VSTSDK to do a plugin, I never had to worry about accumulateOutput. The plugins simply didn’t work as a send effect in cubase.

I wouldn’t waste any time worrying about it - I’ve just checked-in a bunch of changes that eliminate that parameter and simplify the processBlock callback… Have a look at the tip for more info.

Aha - just having to tweak my plugin wrappers/code against this change, now that I’ve grabbed the latest tip from svn!