search

VoggLyster / DiodeLadderFilter

Virtual Analog implementation inspired by the VCS3 diode ladder filter
MIT License
13 stars 3 forks source link

Hi! Looks cool! Thanks for posting a diode ladder filter emulation! Quick question: #1

Open 01GOD opened 3 years ago

01GOD commented 3 years ago

Hi! Looks cool! Thanks for posting a diode ladder filter emulation! Quick question:

The seemingly largest FOSS music framework (AudioKit) on iOS platform has a tb303 filter emulation that seems wrong and it would be appreciated if can advise on how to fix the issue. The source code is written in C.

The file is here: https://github.com/AudioKit/AudioKit/blob/b7b68ce544f5009e12ef439d56130187dedaec25/Sources/soundpipe/modules/tbvcf.c

Supposedly based on the Csound opcode of the same name. Currently the filter emulation weirdly "peaks" when co frequency is lower, instead of when it is higher. That seems like a good first step to making it sound MUCH better. Any tips on how to make it peak when the co frequency is higher instead?

I was looking at lines 87 to 107 to try to solve it as that seems likely to be where that issue is, but I am not familiar with filter emulation math. Thanks in advance for guidance on that.

PS: Apologies for asking by opening an "issue", but there was no contact info on vogg.dk. Oh, and by the way, likely would be very welcome to port the VCS3 filter to AudioKit if ever up for that. It's a FOSS project with a lot of public view and app installations.

PaulBatchelor commented 3 years ago

@01GOD @VoggLyster This code base would need a license compatible with MIT in order to port it to Soundpipe/AudioKit.

I'd be happy to do the port myself, but I'd need this clarification done first.

01GOD commented 3 years ago

@PaulBatchelor Thanks for notifying and stating so. Hopefully @VoggLyster will see that and add the MIT licensing soon.

Also thanks a bunch for the programming contributions on SoundPipe and AudioKit!

VoggLyster commented 3 years ago

Hi guys. Sorry for being so slow with a response, but I just added a MIT license :) I need to ramp up my GitHub game

01GOD commented 3 years ago

Oh, thanks for doing so! Hopefully he will get that ported. I will likely analyze it to learn more about filter emulation also.

On Thu, Aug 19, 2021 at 4:52 AM Søren Lyster @.***> wrote:

Hi guys. Sorry for being so slow with a response, but I just added a MIT license :) I need to ramp up my GitHub game

— You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub https://github.com/VoggLyster/DiodeLadderFilter/issues/1#issuecomment-901850779, or unsubscribe https://github.com/notifications/unsubscribe-auth/ACJ7JDTMUW3T7CLYH75UMQ3T5TV6XANCNFSM4525CM5A . Triage notifications on the go with GitHub Mobile for iOS https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675 or Android https://play.google.com/store/apps/details?id=com.github.android&utm_campaign=notification-email .

01GOD commented 2 years ago

@PaulBatchelor Hi! Any progress on that? Recently started using AudioKit again and it would be wonderful to have a nice audio filter. I haven't used Juce before or done much filter maths studies, so porting that seems daunting. Up for collaborating though, if can tutor some on where the actual filter code is and where to put that in AK.

Thanks in advance!