Re: [LAD] Portable user interfaces for LV2 plugins

From: Stefano D'Angelo <zanga.mail@email-addr-hidden>
Date: Mon Feb 28 2011 - 23:37:02 EET

2011/2/28 Olivier Guilyardi <list@email-addr-hidden>:
>>>> I just dropped explicit LADSPA support from Ingen in favour of NASPRO.
>>>> IMO, if the bridge is inadequate, then the bridge should be fixed, so
>>>> I'm investing in NASPRO, so to speak, so hopefully it remains a vibrant
>>>> project :)
>>> I am really glad to read that this gap between LADSPA and LV2 is about to disappear.
>>
>> Likewise.
>>
>> I think I am going to create a "LADSPA metadata" LV2 bundle with a
>> (hand-curated) data file with extra info about various LADSPA plugins,
>> particularly classes (plugin categories) for plugins without lrdf.
>> LADSPA plugins not being categorized in the menu is the user-visible
>> kink in integration right now...
>
> Hmm.. Does the current bridge rely on LADSPA rdf files to be present? If so then
> I would say that it doesn't really provide backward compatibility from LV2 to
> LADSPA. AFAIK, ladspa.h is the specification, and I would hope that the bridge
> is able to detect and load any plugin which follow this specification.

Just answering to this part since tonight I'm too tired.

The current NASPRO bridge from LADSPA to LV2 does not depend on LRDF
files, yet it uses them if found to provide extra metadata. After all,
that's what they are for.

However, that part currently depends on librdf, and I've been so lazy
not to provide ways to build the bridge without it. However it should
be easy to modify. But since the new bridges are in the making and top
priority here, I guess they will be released more or less by the time
LV2r4 and the next SLV2 will be released, so it won't take long.

Unfortunately the LRDF part won't be there due to a complete rewrite,
and support for that thing will be delayed to some later release (but
not too much) since I want to avoid librdf. In this regard, I wanted
to use libxml2 directly, is that ok for you? (However, I will also
provide a clean way to build without LRDF support, so...)

>> Porting is, of course, even better. A tool that uses slv2 and
>> dyn-manifest to dump out a bundle for a wrapped plugin would do almost
>> all the LADSPA=>LV2 porting work for you, and is trivial to write...
>
> In the Android case, this is entirely possible yes, during the APK packaging phase.

Not that easy. You would need to change the names of a few functions
and check that the connect_port() callback handles NULL values at
least, in most cases. Easy and fast to do... unless the LADSPA plugin
itself does weird stuff (but this seems not to be the case in most
plugins).

Stefano
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Received on Tue Mar 1 00:15:04 2011

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