Pops and cracks - Carla as plugin inside Carla

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eclepticbox
Established Member
Posts: 23
Joined: Mon Dec 29, 2014 8:17 pm

Pops and cracks - Carla as plugin inside Carla

Post by eclepticbox »

I'm experiencing a strange issue when using carla-rack (or carla-patchbay) as a plugin inside carla or carla-patchbay standalone.
Steps to reproduce the issue:
Inside carla-rack (or carla-patchbay) I load an synth (tested with Zynaddsubfx LV2, or a sfz sample, or Calf monosynth LV2).
When I play with an external keyboard (external midi controller or even VMPK) I hear pops at NOTE ON and at NOTE OFF, and occasionally cracks during the note.
There is no issue playing internal Carla keyboards in the edit window.
No issues in Carla standalone, with the same instruments.

No XRUNS reported in Cadence.

Importing the same instrument in carla (or carla-patchbay, or carla-rack) it's all OK.

Carla-git 1.9.8 (2.0-beta6)
debian 9 stable
kernel 4.9.0-6-rt-amd64 from debian stable (the same with the default 4.9.0-6-amd64)
Roland UA25EX

I'm testing this configuration because I would like to use Carla for live playing as a synth rack. I'd like to use carla-rack or carla-patchbay as plugins in order to create "Patch" or "Program" as in hardware keyboards (synths + effects), and to combine them at higher level in carla standalone as the "Performance", "Combi", "Setup" in hardware keyboards.

Help needed...
eclepticbox
Established Member
Posts: 23
Joined: Mon Dec 29, 2014 8:17 pm

Re: Pops and cracks - Carla as plugin inside Carla

Post by eclepticbox »

Hi falkTX!
Now I noticed that pops and cracks are not only at the note on or note off, but at every midi message: pitch bend, aftertouch, CC...
Only in carla-rack or carla-patchbay as plugin...

44100 Hz
buffer size 512 samples 3 period with kernel 4.9.0-6-amd64 (latency 11.6 ms)
buffer size 128 sample 3 period with kernel 4.9.0-6-amd64 (latency 2.9 ms)

engine JACK

In attached a simple project with zyn.
Send MIDI from external device, i.e. VMPK, play a note or move modulation or whatever when a key is pressed).
Attachments
test-with-issues.tar.gz
(4.53 KiB) Downloaded 55 times
eclepticbox
Established Member
Posts: 23
Joined: Mon Dec 29, 2014 8:17 pm

Re: Pops and cracks - Carla as plugin inside Carla

Post by eclepticbox »

I'm sorry to stress Carla...but I think it could have a good place in a live keyboard rig!
eclepticbox
Established Member
Posts: 23
Joined: Mon Dec 29, 2014 8:17 pm

Re: Pops and cracks - Carla as plugin inside Carla

Post by eclepticbox »

I can reproduce the issue. weird nobody else reported it so far.
Will try to take a look at it on the weekend.
I don't want put you in a hurry, :wink: rather I would thank you for all the hard work in kxstudio, but what's the status of this issue?
If a solution can't be found in short time, I'll take another route for organizing sounds in Carla.
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