GStreamer LV2 wrapper only exposes the mono variant of x42-dpl (stereo missing)

[slugica]

Hi, and thanks for the great limiter!

Ardour correctly detects both variants of x42-dpl:

• http://gareus.org/oss/lv2/dpl#mono
• http://gareus.org/oss/lv2/dpl#stereo

But GStreamer’s LV2 wrapper only exposes the mono plugin:

gst-inspect-1.0 | grep dpl lv2: gareus-org-oss-lv2-dpl-mono

The bundle contains both definitions in a single dpl.ttl, but GStreamer seems to only pick up the first variant.

Question:
Is there a recommended way to make GStreamer recognise the stereo variant (dpl#stereo)?
Does the LV2 bundle need a different structure (e.g. separate TTL files), or is this a limitation on the GStreamer side?

Thanks!

[x42]

Does the LV2 bundle need a different structure (e.g. separate TTL files)

It's perfectly valid, and very common to have multiple plugins (which may even be entirely unrelated) in the same ttl.

That looks like a bug in gstreamer. Judging from the output the # anchor in the URI is ignored.

Try lv2ls to list all installed plugins

[slugica]

Try lv2ls to list all installed plugins

Thanks for the clarification!

Both variants are correctly visible in my system:

lv2ls | grep dpl http://gareus.org/oss/lv2/dpl#mono http://gareus.org/oss/lv2/dpl#stereo

But GStreamer only exposes the mono plugin and seems to ignore the fragment after #:

gst-inspect-1.0 | grep dpl lv2: gareus-org-oss-lv2-dpl-mono

Looks like a GStreamer LV2 bug indeed.

Do you have any suggestion for a possible workaround on my side?

Thanks!

[x42]

Do you have any suggestion for a possible workaround on my side?

I suppose you could edit the manifest.ttl and and dpl.ttl files and remove the mono version.

..or try to re-order them in manifest.