'sidechain source' audio-in feature problems

[starwarswii]

i was messing around with various instrument vsts that support audio in, and i noticed that only SOME of them show the 'sidechain source' dropdown, allowing you to use that input

for example, Surge XT, Arturia Pigments, and Voltage Modular all support audio inputs, but the sidechain source option only appears on Voltage Modular out of the three. for the other two it seems impossible to use that audio in

i notice that in the plugin manager, Surge XT and Pigments are listed as having 1 input, as opposed to Voltage Modular's 4 inputs. i guess these first 2 plugins accept mono audio, is that what's tripping it up? maybe mixcraft only shows the menu if there's at least 2 inputs, stereo.
though there are also other plugins that list inputs that don't actually seem to have them. it might be a distinction between audio in and midi in? maybe this should be distinguished between in the plugin manager?

another question, how do you even use both (stereo) sidechain inputs for voltage modular? is it even possible? you can only select 1 sidechain source, and this sends the audio data to 2L and 2R. but how do you pass audio into 1L/1R?

am i just overlooking something? or is it true that sidechain inputs only work with these very strict requirements? it seems short sighted

if i missed something, let me know

TLDR, i think the sidechain system is limited / not functioning fully? it only seems to support a single stereo input, but should be updated to support any number of inputs, including a mono input. it should be more flexible, with a menu of some sort like how instrument output channels work

[Acoustica Greg]

Hi,

Not all plugins offer a sidechain option. If the plugin has a sidechain option, Mixcraft will display it. Traditionally, maybe only a compressor plugin might have a sidechain option.

But Mixcraft has an audio control feature that allows you to use audio to control any parameter in any plugin: https://acoustica.com/mixcraft-10-manua ... er-modules

In regard to the audio sources, if you use Voltage Modular FX as an effect on a track that has an audio on it, that audio will go to 1L/1R. The sidechain input goes to 2L/2R as you found.

Greg

[starwarswii]

Not all plugins offer a sidechain option...

what does 'sidechain option' entail on the side of the plugin? is there a functional difference between an audio input and a 'sidechain input' for a plugin? i thought sidechain was just a different name for an audio input. i'm curious, what's the code you use to determine if a plugin exposes a sidechain input, and thus you should show the sidechain dropdown?

if sidechain is really a different thing than an audio input, then can you confirm that the '1 input vs 2 input' thing i was talking about has no effect on the sidechain option appearing? aka sidechain works fine and the dropdown will appear if a plugin's sidechain input is mono instead of stereo

But Mixcraft has an audio control feature...

there are a decent number of synths that offer external audio inputs, where the audio can be mixed and used in complex ways not achievable by the basic 'audio controller' option. it would be nice if we could take advantage of that in mixcraft, since a lot of the logic is already there in the sidechain system

In regard to the audio sources, if you use Voltage Modular FX...

so the only way to take advantage of both of the audio inputs is to use voltage modular as an effect? that seems pretty janky. it would probably be easier to understand if both inputs could be 'sidechain' inputs and could be selected on the instrument

i tested it out. here's an example image of the setup required to use the midi input and both audio inputs for voltage modular:

voltage modular all inputs.PNG (776.19 KiB) Viewed 242 times

it demonstrates how it's pretty unintuitive, the options to make this work ('use midi from track', 'sidechain source') are scattered across 2 different menus. i feel like thinking of voltage modular as a midi instrument with 2 audio inputs is more intuitive then thinking about it as an effect with 1 aux audio input and 1 aux midi input. thus this setup would be slightly easier to understand if instead if was a midi instrument that let you select 2 different audio inputs

also i think this setup is the 'input limit' of mixcraft (1 midi input, 2 audio inputs). e.g. if i had some plugin with 3 audio inputs, (or 2 midi inputs?), i don't know if that would be possible to utilize in mixcraft

[Acoustica Greg]

Hi,

Our code just checks to see if the plugin has sidechain. Some do and some don't. It doesn't have anything to do with the number of inputs. The person or team who designed the plugin made the decision whether to include a sidechain feature.

Thanks for the audio routing suggestions!

Greg

[starwarswii]

Could you get into the nitty-gritty details about exactly what your code does?

I found this documentation about side chains on VST3 instruments:
https://steinbergmedia.github.io/vst3_d ... my-plug-in

As far as I can see here, a side chain input is literally just another audio input? Where is the sidechain specific stuff specified? What logic are you using to determine sidechain-ness? Like is it just the name of the input?

If I’m overlooking something, please let me know, but I’m still kinda confused about how side chains are detected.

Basically just trying to learn more information about why some plug-ins are detected and others aren’t.

[Acoustica Greg]

Hi,

Whether a plugin offers sidechaining is a question for the maker of the plugin.

Greg

[Acoustica Greg]

Oh, one more thing: some plugins have an on/off switch for sidechaining.

[starwarswii]

Put another way, If I wanted to make a plug-in and ensure that side chaining works in mixcraft, what code changes would I need to make? Like what functions do you call on the plug-in to check if it has a side chain available?