zipper noise - Githubissues

openAVproductions / openAV-Luppp

Luppp is a live performance tool, created by OpenAV productions.

http://openavproductions.com/luppp

GNU General Public License v3.0

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zipper noise #223

Closed georgkrause closed 6 years ago

georgkrause commented 6 years ago

When i switch the FX-Button on and off while playing something, there is a short noise. Can someone reproduce this?

Its not audible if the track is silent at the moment. I can reproduce this by recording a note which is one bar long and then turn the send on and of while playback.

harryhaaren commented 6 years ago

this is known as "zipper noise" and comes from the volume value not being smoothed. Thanks for the bug report, yes this must be fixed.

georgkrause commented 6 years ago

is this release-blocking? wont have time for this until next week.

harryhaaren commented 6 years ago

Yes it'd be good to fix this in this release, given its a known bug now. [Update: I'm not in a rush to release - and I'd like to merge the few open PRs first anyway]

georgkrause commented 6 years ago

There are other known Bugs, too which we wont fix i guess. Question is, if this bug is big enough to prevent us from delivering fixes for other bugs. But thats your choice.

Since i have no idea about dsp stuff yet and am pretty focused on the midi stuff, maybe you can look at this? Could also check this out but will take some time...

georgkrause commented 6 years ago

There is also noise on:

between end and start of a clip (not when starting and stopping, only when playing)
moving FX-Knob
turning fx on and off
turning send on and off
moving send knob
moving pan knob fastly
turning key button on and off
moving sidechain knob

georgkrause commented 6 years ago

Okay, after reading the code there is already some kind of smoothing for the volume fader of the track and the master. We could apply the same approach to the knobs. @coderkun propose to do this in a function which will be called everywhere. Not sure about this one.

Another topic are the buttons, because we need to smooth the value against 0.

Anyway, i found the same problem on:

input volume
input mix button
input mix knob
input sidechain signal knob
input sidechain key button
input snd button
input snd knob

georgkrause commented 6 years ago

actually i have the same problem when i move the faders of the tracks fast.

georgkrause commented 6 years ago

I did some testing, on higher samplerates there is still noise, on eg 44.1khz its working pretty nice. This means we need some smoothing calculation based of the samplerate...

harryhaaren commented 6 years ago

Is the bug ready-to-close now with the PR for smoothing controls merged? ( https://github.com/openAVproductions/openAV-Luppp/pull/243 )

georgkrause commented 6 years ago

yes.