On Fri, 2016-10-28 at 17:20 +0200, pfl wrote: > ah yes, I forgot the main loop > > the problem is that the set volume part is only a small part of my program > > so I'll have to put that lop in a thread Note that libpulse is not thread-safe, so if you create a new thread where you run pa_mainloop_run() and then call pa_context_set_sink_volume_by_index() from another thread without first somehow making sure that the mainloop thread is stopped, that's going to break. One solution to this is to use the threaded main loop: https://freedesktop.org/software/pulseaudio/doxygen/threaded_mainloop.html -- Tanu https://www.patreon.com/tanuk