A/B option in plugins

[Urs]

So I'm currently thinking about something like A/B and Undo in some of my upcoming plugins/updates. While the case of undo is relatively simple, the A/B thing unexpectedly puts me in some sort of dilemma:

Do both states save with a patch or just the active one?

Here are some further considerations:

• if both save with patch, one can't load one patch in A and another one in B
• if only one state saves, the A/B thing gets lost when working on projects
• saving both states considerably expands the preset folder
• loading both states may considerably bloat ram usage for MIDI Programs
• we could revert to Edit/Compare on plugs with huge memory fingerprint, but do A/B on smaller effects (which have yet to be spotted from u-he)

Hmmm...

How is it done in other plugins? I see it a lot especially on high fidelity mastering tools and analog emulations, but I don't have any around

Have your say,

Urs

P.S.: Undo is simple because it doesn't save with patch/song. As changing a patch is an undo-able thing (eeeek, how ambiguous), whole patches would be part of the undo list. If that was the case, patches would quickly build up with patches that contain patches which contain further patches and so on. Hence storing the undo history would not only provoce immense memory usage, it would also create a paradox: If I load a patch and hit undo, do I go to the point before loading the patch, or do I jump into the undo-history of that patch first? Hence no save of undo history.

[amoeba]

wonderful idea. i've been saving a test patch and flipping back/forth between the original as a jankey A/B system. a plain old compare would be great. keep it simple, save active state only. don't overthink it man, save those brain cycles for... other things.

[Kyran]

I've only seen A/Bs on stuff like compressors, and there they're used to compare the settings: ie see which one works best. So you could load a preset, store it in the A state, start tweaking and then quickly compare if you're improving the sound (which not always the case with compressors)

In this scenario it doesn't really make sense to store them both, because it's just a tool to help you tweak the patch.

Storing both states is interesting if you could for example morph between two patches with a knob or something.

Anyway: I'd just save the current state

[tony tony chopper]

Do both states save with a patch or just the active one?

Here it works like this:

-Instead of A/B I have "a spare state". That allows to do everything with just 2 buttons: "store in spare state", and "flip with spare state (A/B compare)". With A/B buttons, you need an A & B pair of buttons, but also a "copy to other". And I find it clearer to have a master state & a spare state.

-I give an option to lock the spare state, so that the user can store something in the spare state, flip presets and compare with the old spare state.

It's implemented in IL Parametric EQ 2, Fruity Limiter, Maximus & works well.

[suthnear]

I always think of A/B as being a comparison between the hard saved state of the preset and the current edited state (I assume that this is what you mean by edit/compare). So then one state is simply the point at which the undo stack is empty. I've always found this a very useful feature. I'm not sure of the utility of having two entirely different states for a synthesizer, though. With effects it can make sense, I suppose, since one may wish to quickly compare small variations between patches. The method suggested by tony tony chopper sounds pretty workable either way. Having said this, I generally just load 2 instances with the same patch and then edit and bypass as required.

As an aside, one very useful feature of the nord g2 is patch variations: basically each patch has 8 variants accessible via buttons on the keyboard. The restriction is that each must feature the same modules and wiring between them. I have a lot of z2 patches that are structurally identical but radically different sounding so this would be quite useful.

[djsubject]

all very interesting

Undo =

A or B don't both need to be saved IMO we have program change & easy loading presets why would we need 2 presets loaded at the same time if we can only use one?

A/B would be useful during work flow, but no need to save (all IMO of course)

Subz

[psycox]

it would be fine to morph between the two states a/b but i know this is very complex.

[Superballoon]

Some 2 cents:

Logic Pro 8 has this built in - you can A/B plugin settings. It works very smoothly and easy. I am not sure if this a trend in hosts, but if other hosts start picking up/already has this feature, it is not necessary for plugins to provide this functionality additionally?

I'd rather see your brilliant brain thrown at a sampler or compressor, Mr GeniUrs.

[tony tony chopper]

I've considered implementing this in FL already, but there's a little problem: a plugin may not A/B compare its whole state. For example, if a plugin is tabbed, or offers editing switches, it may save those in its plugin state, but an A/B comparison shouldn't start switching tabs, it should only flip the state that matters for audio processing.

As an example, in my EQ I'm talking about, the A/B comparison doesn't touch the oversampling option & the bands display & monitoring options. A host wouldn't be able to do this.

[blurk]

I voted for "only the current state saves (A or B)" but I'd actually go so far as to say only save state A, i.e. one state is the "current" state and the other exists purely for comparison. This could avoid accidentally saving the wrong state if the user forgets to flip back. Of course, the UI will need to make it clear which state is the "current" state and which is the unsaveable comparison state.

[twolegstoneworks]

I voted for "Only the current state saves". Unless you're thinking about implementing morphing between 2 presets, in which case I would suggest saving of a special layer-preset, which basicly only contains the path and filename of the 2 presets to load.

Morphing between presets would be a cool thing to have. But with Zebra we already have lots of morphing capabilities with the x-y areas. Layering of presets would be a cool thing too, as seen in Albino 3, but it's quite cpu-hungry. Being able to morph between different pre-set states of the same preset would be cool too (think FM8/Kore 2 here), but I guess I'm in the "wishing for green snow"-state of mind now

Cheers.

[pdxindy]

Just a simple compare button (A/B) sounds fine with me. Saving both states sounds overly complicated to me and not necessary. If I want both, I just save another preset. So I voted option 1...

What I have thought about before would be a row of buttons on the performance page allowing saving of X-Y states... but that is something other than what you are asking about here.