module-ladspa-sink: How can I use run_adding?

Submitted by ovv..@..web.de

Assigned to pul..@..op.org

Link to original bug (#105806)

Description

Created attachment 138417 patch for run_adding

The run_adding function provided by some LADSPA plugins can be used to add the plugin output scaled with a specified gain instead of using its output directly. So you can use it to specify the wet/dry level, can't you?

I've tried to implement it to module-ladspa-sink. The patch is in the attachment.

When I tested it with the glame butterworth lowpass filter (butterworth_1902.so from swh plugins), the debug message telling the configured gain appeared. However, run_adding didn't work, I've set run_adding_gain to 0.1 and 10, the output was the same both times, as though run instead of run_adding was used. I've also tried setting the gain directly before run_adding is executed: https://pastebin.com/mj3tBgaB But it didn't change anything.

Patch 138417, "patch for run_adding":
0001-LADSPA-module-Support-run_adding.patch