Subject: Re: [linux-audio-dev] Wrappers and LAAGA
From: Paul Davis (pbd_AT_Op.Net)
Date: Sat Jul 28 2001 - 05:54:10 EEST
>> I was wondering whether it was possible to implement LADSPA on non-Linux
>> OSes, and if so, whether it has been done? For example, without breaking any
>> licenses (by clever dynamic linking if necessary) could a DirectX, VST, MAS
>> or TDM wrapper/adapter be written for it (if any of these provide a superset
>
>I think it would be possibel to write a VST wrapper for example (I don't
>know enough about the others), but you would loose functionality, and the
>plugins would have to be recompiled.
maybe, maybe not. somebody has done some neat tricks to get Buzz
plugins (written for windows) working without recompilation under
linux/x86 with a linux-specific tracker.
before anyone gets too excited about the question of using binary VST
plugins under Linux: the problem with VST plugins is that they just
about always include GUI code, via libvstgui/win32/macos calls, and
these don't exist for linux. in addition, its unfortunate but true
that many VST plugins include OS and h/w dependent code, so there is
little hope of doing the Buzz thing. rather sad :)
>On the subject I realised the other day that I placed my plugins under
>the GPL, IIRC that means that they couldn;t be used by a non gpl
>compatible app, not quite what I intended, but, oh well.
This isn't true. No application is written with the intent of linkage
against your specific code, and since all LADSPA-using applications
will function completely normally in the absence of any LADSPA
plugins, use of your plugins falls under the "run time linkage
exception" that has emerged by consensus for the GPL v2.0 (but *might*
be eliminated in version 3.0). Basically, run-time linkage is not
explicitly covered at all by the GPL and differs greatly from
compile-time dynamic or static linkage. Ardour is not a derivative
work of your plugins just because it can be used to rt-link them and
call their functions - Ardour is 100% functional without your
plugins. Note that Ardour never includes any symbol names from your
code, so it would be extremely hard to argue that its a derivative
work. If its not a derivative work, I can make it as proprietary as I
want without your use of the GPL affect me.
As you can see as you soon as you begin thinking about this, the whole
issue of what a "derivative work" really is gets very murky with
run-time linking present. Under v2.0, its so murky that its generally
accepted as not violating the GPL; hence non-GPL binary-only kernel
modules, for example. Of course, that reverses the direction of the
GPL-effect-via-runtime-linkage, but I think its equally murky in
both directions. RMS is said to be working on trying to clarify this
in v3.0, for obvious reasons.
--p
the GPL-coverage-via-run-time-linking, but I think its similarly murky
in both directions.
--p
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