<html> <head> <style></style> </head> <body class='hmmessage'> > Hmm, tricky problem. I'm not sure that the current setup with ladspa > sinks really allows this. > > I think that to do this, the actual sink created by the ladspa module > would have to be unloaded when a certain "port" was used by the sink it > connected to. This requires more smarts than it can currently cope with. > > > If it is not possible then how do I detect in my LADSPA plugin if the > > headphones are connected? I assume there is some API that I can use? > > Well, I think it would require rather a lot of hacking. > > In theory, this is what you need to do (I think): > > Write a PA module that is similar to the ladspa one. When it specifies > a master sink to use, you can (in the PA module code) inspect the port > currently selected for that sink and get notifications when that port > changes. Your module could sit there and wait for the "headphone" port > to be activated on the sink and only then create the actual virtual > ladpsa sink. > > At present the ladspa sink is created at module initialisation. > > The way I look at it there are two choices: > > 1. Modify module-ladspa-sink to have a "master_port" argument and make > it only create the virtual sink when the master sink's port matches the > argument value (and to unload it when it changes). > 2. Rewrite your ladspa plugin in PA using the git master virtual sink > as a basis for the code. > > > Even when this is all done, you will still not get everything working > 100% perfectly just yet. Jack sensing is (apparently - not looked for a > while) a mess and does not work reliably on all drivers. We need to fix > that and probably will enable automatic port switching on jack status in > due course. But until this comes in, when you plug in your headphones, > you have to manually change the port in pavucontrol (labelled connector > in gnome tools). > > Col   Thank you for the answer. Do you think it would be possible and a good idea to make the DSP as a kernel module instead? I want the DSP module to be usable in different linux distributions - also those that do not use PulseAudio by default.    I also have another problem with module-ladspa-sink - it seems to only support mono, so I would have to change that as well. /Kim </body> </html>