Dragonfly Room verb attacked me last night

#21

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.

Ardour Maxed Out
#22

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!

#23

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

#24

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

#25

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…

#26

Found a way to consistently reproduce the bug.

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

2 Likes
#27

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.

#28

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.)

#29

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
#30

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.

#31

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.

#32

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.

#33

That is based on Ardour 6.2.33

#34

What was this other plugin ?

#35

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 :-/

#36

Interesting I never had any issues with this plugin, I will be caution, especially with headphones,

#37

I’m still working on an overhaul that should hopefully prevent these bugs, but like many people this year has been tough for me and it is slow going. Hopefully it won’t take forever.

1 Like
#38

Very much appreciated @Michael_Willis and completely understand about the year trust me.

2 Likes
#39

Yep, what @seablade said. Take your time, take care of yourself first and then tame that dragon(fly).

2 Likes
#40

@x42 Is it possible for one plugin to be a bad actor and invade heap memory allocated by another plugin, maybe through bad pointer math or a buffer overflow?

I’m doing a deep dive, taking apart freeverb3 and rewriting it one function at a time. I am particularly scrutinizing how it implements buffers and feedback variables, because this bug could be caused if anything goes wrong with those.

So far I haven’t found anything that looks suspect. I’m wondering if operating systems do anything to protect memory between different .so/.dynlib/.dll libraries that are used within the same process.

I hate casting blame, and I’m still looking for a root cause in the dragonfly plugins, but it is really suspicious that some people report that they never experience this problem, and others repeatedly experience it. As for myself, I had one Ardour project in which Dragonfly Room would regularly explode, but I lost it to a hard drive crash and I don’t think that I had a backup. In my other projects I haven’t experienced this bug in a long time, probably a couple of years.