Hello everyone, I found bug in splitcomb.c module. At line 535: 534 /* Generate zero frame. */ 535 pjmedia_zero_samples(sc->put_buf, 536 this_port->info.samples_per_frame); method have invalid buffer size. Should be : 534 /* Generate zero frame. */ 535 pjmedia_zero_samples(sc->put_buf, 536 port->info.samples_per_frame); because this_port->info.samples_per_frame is size for all channels not for one. regards