[Ardour-Users] ambix LV2 vs ardour?

[Robin Gareus]

On 2/21/19 12:52 AM, Fernando Lopez-Lezcano wrote:
> Hi all,
> 
> Anyone out there successfully using the Ambix (0.2.8) LV2 plugins with
> Ardour5?
> 
> I am having problems loading any of the plugins into Ardour5. This
> happens with both the Fedora ardour package and the demo install from
> Ardour.org. The Ambix plugins do load, for example, in Qtractor, but not
> in Ardour.
> 
> Ardour shows them in the plugin manager, you can select one, "Add" it
> and then when you do an insert it a panel pops up that says "the plugin
> xxx could not be loaded". Looking at the log I see (for example):
> 
> [ERROR]: LV2: Failed to instantiate plugin
> file:///usr/lib64/lv2/ambix_converter_o1.lv2/ambix_converter_o1
> 
> The directory looks like this:
> 
> ls -l /usr/lib64/lv2/ambix_converter_o1.lv2/
> total 5068
> -rwxr-xr-x. 1 root root 5171056 Nov 29 20:43 ambix_converter_o1.so
> -rw-r--r--. 1 root root    5504 Nov 29 19:50 ambix_converter_o1.ttl
> -rw-r--r--. 1 root root     901 Nov 29 19:50 manifest.ttl
> -rw-r--r--. 1 root root     378 Nov 29 19:50 presets.ttl
> 
> I built the plugins according to the build instructions, and nothing
> weird is shappening there that I can see (the build uses a recent
> lv2-devel package, etc). All the Ambix standalone applications that are
> also built work just fine with jack.

I just had a quick look. The plugin has an invalid URI, it just uses the
plugin-name as-is.

liblilv will prefix that with the absolute path, resulting in a
file://URI, and when Ardour tries to instantiate the plugins this causes
a failure. The given URI does not match the URI in the plugin's so. It
also fails with jalv. I'm surprised that it works in qtractor, perhaps
you were using the VST, there?

Could you try patching ambix like http://paste.debian.net/1069875/ (That
patch also includes an update for zita-convolver3 new API and removes a
call to fftw's thread-safe planner which is for a plugin-host to make.)

Or try this one stop script:
  http://robin.linuxaudio.org/tmp/compile_ambix.sh

That doesn't link statically, but it should work with a local Ardour
build at least.

Cheers!
robin