Does system performance matter when rendering not in real-time?

[Mayae]

It could sound like the plugin is rendering multi-threaded, and the threads can't keep up somehow, causing buffer underruns - possibly caused by the host offline rendering in threads as well, causing less time per thread..
It's still no excuse though, threads should be synced obviously.

Maybe you are suggesting a bug in Reaper (the host)? That would be technically possible, but I think unlikely, because they guys making Reaper seem very competent.

No, a bug in the plugin. The situation i wrote is exactly the same as JCJR.

I see now what you mean. They'd need this:

Code: Select all

if Offline then Wait;

More like not this:

Code: Select all

float buffer[7.1][HUGE_NUM][64-bit];

void do_wurk_thread1()
{
	static int phase;
	// 3 ghz processor means this will run 3 billion times a sec LOL
	for (auto & sample : buffer)
		buffer[rand()][phase] = sin(phase++);
}

void do_wurk_thread2()
{
	...
}

void processReplacing(float ** in, float ** out, int frames)
{
	for (int i = 0; i < frames; ++i)
	{
		// lol new processors so fast with many cores, ofc threads will always be ahead
		out[0][i] = in[0][i] + buffer[i][y][z];
			...
	}
}

[hot_frequency]

I do not own the plugin in question, but if you do 16 channels of audio, but only one instance of EWQL Choir loaded onto one of those tracks, does the crackling still present after render?

[BachRules]

I do not own the plugin in question, but if you do 16 channels of audio, but only one instance of EWQL Choir loaded onto one of those tracks, does the crackling still present after render?

When I do that, I perceive no crackling.

Not sure if you meant 15 audio tracks without WAV data in them or with WAV data in them, so I tried it both ways. In either case, no crackling perceived.

[BachRules]

Can you reproduce the problem in another situation (ie. another daw....)?

I'd like to try to reproduce it without Reaper. Is there a suitable free VST host?

[whyterabbyt]

Can you reproduce the problem in another situation (ie. another daw....)?

I'd like to try to reproduce it without Reaper. Is there a suitable free VST host?

There are more than a few commercial ones with fully-working demos.

[BachRules]

There are more than a few commercial ones with fully-working demos.

Thank you.

[hot_frequency]

I do not own the plugin in question, but if you do 16 channels of audio, but only one instance of EWQL Choir loaded onto one of those tracks, does the crackling still present after render?

When I do that, I perceive no crackling.

Not sure if you meant 15 audio tracks without WAV data in them or with WAV data in them, so I tried it both ways. In either case, no crackling perceived.

Interesting; you made no mention about there being data in your dummy/test sessions, so I was not taking that into account. However sample math is sample math, so I imagine the wav's could be noise for the purpose of our exploration.

Try adding another instance of EWQL choir to a second track; try the render, see what happens. If not crackling/distortion, add another instance, rinse, repeat. See how many instances before this distortion asserts again.

[BachRules]

...you made no mention about there being data in your dummy/test sessions....

I tried:

... No MIDI, except on track 1....

Try adding another instance of EWQL choir to a second track; try the render, see what happens. If not crackling/distortion, add another instance, rinse, repeat. See how many instances before this distortion asserts again.

It takes more than 1 instance, fewer than 16, before the crackling becomes perceptible on my system. What will the exact number matter?

EastWest tells me they get no audio problems when they render my Reaper test-file on various systems. They tried a harder challenge, 31 instances of Choir "with multiple Firefox tabs, multiple Chrome tabs, Mail, Messages and iTunes all open."

[BachRules]

Can you reproduce the problem in another situation (ie. another daw...)?

Cubase + Spaces --> crackling:

- Cubase project: https://drive.google.com/file/d/0B5ZYXb ... sp=sharing
- rendered WAV: https://drive.google.com/file/d/0B5ZYXb ... sp=sharing

[j79]

I dont use EW, but i have experienced similar things once a long time ago with a specific plugin, dont remember which to be honest.

Anyway, checking "inform plugins of offline rendering state" in Reaper preferences -> plugins -> VST made the issue go away back then...might be worth a try if you havent tried it already.

[BachRules]

I dont use EW, but i have experienced similar things once a long time ago with a specific plugin, dont remember which to be honest.

Anyway, checking "inform plugins of offline rendering state" in Reaper preferences -> plugins -> VST made the issue go away back then...might be worth a try if you havent tried it already.

I just tried selecting it, and makes the crackling definitely worse.

In any case, I am confused why Reaper would not have "inform plugins of offline rendering state" selected by default. Without that selected, Reaper's default rendering scheme is to render as fast as possible, but without informing VST's it's rendering offline. If I were a VST and the DAW told me it was operating online, but then it sent me process-buffer requests faster than realtime, I might get confused.

It was worth a try, and it's interesting that it makes the crackling worse. Thanks for the information.

[BachRules]

I reported this EastWest Spaces bug on http://www.vi-control.net/forum/viewforum.php?f=32 , and a moderator there, "Hannes_F", replied:

most composers that use QL Spaces know that its audio quality is superb. It is one of the most pristine reverbs available.... I'll be on your heels for a while now.

vi-control.net staff subsequently blocked me from posting on their forum, without explanation.

Also, on May-14, EastWest emailed me:

RE: Update for Case #55999 - "Crackling noise from Spaces"
Hi,

We will release an update addressing these issues, as well as many other issues ASAP. Thanks for your patience!

Mike
support(at)eastwestsounds.com