s->filter = gst_element_factory_make("volume", NULL);
s->sink = gst_element_factory_make("autoaudiosink", NULL);
if(!s->source || !s->filter || !s->sink) {
s->filter = gst_element_factory_make("volume", NULL);
s->sink = gst_element_factory_make("autoaudiosink", NULL);
if(!s->source || !s->filter || !s->sink) {