Dragonfly Room verb attacked me last night

Another hint…

Ardour calls plugins to process data in-place (input buffers == output buffers). LV2 plugins that specify http://lv2plug.in/ns/lv2core#inPlaceBroken are currently not supported.

I recall that various freeverb calls expect a non-constant input buffer that are distinct from the output, and you first have to copy the input to the plugin to a temporary buffer (which could be on the stack).

Thanks for the hints, @x42. I think the Shuttle Speed thing was a red herring, since @serdeman just barely communicated on the Github issue that he experienced the bug immediately after opening an Ardour session with Dragonfly Room on a bus. However, it is a good hint that Ardour uses the same buffer for input and output. I either didn’t realize that or forgot; I’ll double check my source code and see if this might be a reason for this bug.

It would help if everybody here who has experienced this bug would please answer the following questions:

Which Dragonfly plugins do you use?
Have you experienced this bug recently? (Let’s say in the last six months)
Which plugin(s) exhibited the bug?
Do you run multiple instances of Dragonfly plugins in one project, or a single instance?
Which version of Ardour are you using?
What CPU do you have?

Which Dragonfly plugins do you use? All four
Have you experienced this bug recently? Yes
Which plugin(s) exhibited the bug? Hall
Do you run multiple instances of Dragonfly plugins in one project, or a single instance? Sometimes two, sometimes one
Which version of Ardour are you using? 6.2 (but I think I experienced the noise in 5.12, possibly 6.0)
What CPU do you have? AMD FX-6300

@robertodealmeida You say that it was fixed for a while, but recently started happening again. Do you know which version(s) of the plugins you were running that did not exhibit the bug? Do you know when it started happening again?

Hi, I stumbled upon this topic and I have experienced this bug multiple times as well.

Which Dragonfly plugins do you use? Room and Hall.

Have you experienced this bug recently? Yes, absolutely.

Which plugin(s) exhibited the bug? Room for certain, Hall, I’m not quiet so sure but I would say probably.

Do you run multiple instances of Dragonfly plugins in one project, or a single instance? Both, depends on the session.

Which version of Ardour are you using? The bug happened with 5.12 and 6.0

What CPU do you have? Intel i7-3770

It used to be very frequent, to the point that I stopped using DragonFly until recently (a couple of weeks or so), I haven’t had it since. Also, I don’t know if this is relevant but I almost always use it in a bus.

I hope this can help.

It happened to me (not for the first time) yesterday: I opened a two-month-old session and the bug hit me (luckily when I open a session I let the headphones on the table and look at the meters, just in case :wink: ).

  1. Dragonfly Room
  2. yes, yesterday 2020-07-22
  3. Dragonfly Room
  4. single instance, in a bus
  5. Ardour 6.2.xx self-compiled from yesterday’s git (I have experienced the bug in 5.12 from Debian as well)
  6. An 8-year-old Intel Core i5-2450M

It doesn’t happen too oft, and when it does I just delete the offending plugin and insert a new instance. Thanks for your work!

Which Dragonfly plugins do you use? Hall + Plate
Have you experienced this bug recently? (Let’s say in the last six months) Yes (June)
Which plugin(s) exhibited the bug? Hard to tell, had several instances, didn’t investigate at the time
Do you run multiple instances of Dragonfly plugins in one project, or a single instance? multiple
Which version of Ardour are you using? 5.12
What CPU do you have? 4x Intel Core i5-3570 @ 3.4GHz

This has happened to me many times as well. I used the DragonFly reverbs a lot in Carla, when practicing. (Just Carla, not in Ardour.) When reopening a saved Carla session, sometimes the plugin would produce a very loud noise. It never occurred during a session, only on opening it.

It was also inconsistent and I was not able to reliably reproduce it consistently.

Which Dragonfly plugins do you use?
Plate, Hall, and Room.

Have you experienced this bug recently? (Let’s say in the last six months)
Yes. (My current version is 3.0.0.)

Which plugin(s) exhibited the bug?
Hall and Plate for sure. I am not sure about Room.

Do you run multiple instances of Dragonfly plugins in one project, or a single instance?
Both, but it certainly occurs with one instance.

Which version of Ardour are you using?
I had it with 5.12. I haven’t used 6/6.2 enough, though.

What CPU do you have?
Intel Core i7-4771

I was attacked tonight by another reverb plugin as well: Calf Reverb. Why they are so angry at us?

The first time it happened I immediately remembered this topic. I took off my headphones, and went to see who was to blame. It was just turning off the reverb effect that everything stopped. It happened twice and never again

It was a MIDI piano track and it had a vinyl simulator too. I don’t know if that has any influence.

It makes me think that it’s possible that this reverb plugin shares some code with Dragonfly’s or maybe both use some Ardour feature that’s causing it.

I’m using Ardour 6.2 on Ubuntu 19.10 (yes I know I have to upgrade), with jackd, AMD Ryzen 5 CPU…

Found a way to consistently reproduce the bug.

Close session (not quit). Reopen the same session from the session chooser.

2 Likes

This works very well to reproduce the issue.

  1. Hall, Plate and Room.
  2. I’ve tried Dragonfly plugins for the first time two or three months ago on this sole project and It happens very often (Once out of three times maybe).
  3. The three of them.
  4. In separate buses, simultaneously.
  5. Ardour 6.2 from website
  6. Intel i3

I tried metering as Robin suggested on Master meter red and no sound. What I did is putting the meter plugin immediatly after the reverb plugin and I’ve found that it doesn’t produce “Not a number”, Infinity nor Denormals bits/values. It clips at +40 dBFS.

OMG! One heart attack later I can confirm this now for the first time.

(Ardour 6.2, Intel i5, two instances of Dragonfly Hall in this project.)

Hey everybody, I’m still working on this. As I said before, I can’t make any promises about when it will be fixed. I think there is a bug somewhere in the freeverb3 library, since my code is mostly just a wrapper that delegates to freeverb3. I’m digging in to the library itself to see if I can determine whether it is the cause of this bug.

2 Likes

Ok, just had the same bug rear it’s ugly head on a different channel with a different plugin.

This time it happened immediately after doing a Snapshot and switch to new version.

Meters pegged at +40db on the offending channel and the Master. But this channel had a different plugin.

So now I’m thinking it’s just a session open bug. Dragonfly may be more susceptible to it for some unknown reason. But when it happens with more than one plugin, that’s enough for me to take the onus off of Dragonfly.

Just a side-note. +40dB is a limit set by Ardour’s meter display. The signal level may be higher, but meter pegs at +40. This is so that the level can fall off (usually 13.3 dB/sec) in a reasonable amount of time.

I’m mainly mentioning this so that you don’t go off hunting for +40dB (100.0) in freeverb’s source.

Just happened again in Mixbus32C v6.1.22. This time when I selected a snaphot from the Editor List. And the offending buss had Dragonfly Room.

So now I’ve reproduced it on session open in main Session Chooser, Snapshot and Switch, and Snapshot menu in Editor List.

That is based on Ardour 6.2.33

What was this other plugin ?

This is still happening :frowning:
Dragonfly Plate Reverb v3.2.1 on Ardour 5.12
Ouch !!
I ended up putting a limiter on the master channel to at least save my ears … and maybe my monitors :-/