[linux-audio-dev] processing plugin standard wrapper

[Stefano D'Angelo]

> Yes, it's very interesting and it is a path we want to walk. Currently, apart
> of building Ladspa plugins, CLAM also can be a Ladspa host and we should
> extend that to other plugins systems. We have two students in our lab working
> on plugin and hosting aspects, but they need some time for any outcome.

Well, CLAM is a big and important project and I am just an unknown
student from Italy who is trying to develop a replacement for pedal
boards and stomp boxes and trying to let people easily reuse the code
I'm going to write.
Anyway, if you think that me and/or my project
(http://freeadsp.sourceforge.net - the site is not being updated since
we're working on a new one) can contribute, I/we'll be pleased to.

> > But, anyway, maybe combining the two things could be of some interest:
> > imagine that you want to be able to develop and use immediately in all
> > supporting applications a plugin system capable of using the
> > z-transform.
> > In this way you could build a module for this wrapper and
> > soon start programming your plugins and use them, without having to
> > wait for the adoption of "your standard".
>
> CLAM is not an standard to be adopted. Alsa, Jack and so on are the standards.
> CLAM should be a convenience implementation tool. Migration is something that
> can not be expected and we have a lot of experience on that. I am for
> providing interframework wrappers so everyone could develop on the framework
> he is used to (Mathlab, Marsyas, Pd...) and still reuse what it is done in
> other frameworks.

I think it's clear that I'm not talking about a new standard and
things like that. I'm talking mainly about a wrapper. The possiblity
to develop new formats and have them working with any app that uses
such wrapper comes directly from the nature of the wrapper itself...
In other words I was just wondering how things could go after such
thing would be ready and working.
Then, to be honest, I think that if I/we succeed with implementing a
clean way to make VST, LADSPA, LV2, DSSI, etc. work well together,
some already started projects would at least consider the chance of
using such framework.

To be even clearer the "integration" I was talking about could work like this:

Host -> Wrapper -> Wrapper module (plugin loader - one per standard)
-> Processing object (plugin)

In this case the host needs information on how to use a processing object.
But if you put inside such wrapper module also information on how to
build a processing object from an algorithm, than CLAM could use the
same interface to do that other thing.

> > Also, this way some noticeable improvements can be made on performance
> > if this wrapper would be able to represent processing networks which
> > can be "simplified", as for example a net of LTI systems with known
> > transfer function (fourier transform).
>
> Sorry, I don't understand you here.

It's quite simple: if you have a processing standard which represent
processing objects as LTI (linear time-invariant) systems using the
fourier transform of their transfer function (books often call this
H(f)) and you arrange such objects in a network, then, instead of
calculating outputs for each object, you can just multiply all H(f)s
following a certain path and use this result as the H(f) of the whole
network. This would allow network-based optimization (but obviously
the wrapper would have to know how the net is made).
Well, it seems like you're a teacher or a researcher, so you probably
know more than me about these stuff.
This, however, is just a thought.
In case I wasn't clear enough, just tell me.

Regards,

Stefano D'Angelo