Hello there! I am trying to write a real time pitch shifter using C++. The pitch shifter uses resampling and WSOLA for time-scaling. I have written a jack client that already works using C, but I would like to try using zita-resampler as the resampler library for my program. That is why I am rewriting my program using C++ (it would also be a learning experience for me). I looked to Rui's synthv1 and zita-ajbridge for example of writing jack client using C++. The problem I am having relates to Jack MIDI. My program keeps having a segfault when it is trying to read from the MIDI buffer, specifically when it tries to dereference the buffer pointer inside the event structure. jack_midi_event_get(&in_event, midi_buf, event_index); if ((*(in_event.buffer) & 0xf0) == 0x90) // Segfault happens here, on boolean mask operation { _note = *(in_event.buffer + 1); } So I tried to print the buffer's content but it also segfaults. std::cout << std::hex << static_cast<unsigned int> (*(in_event.buffer)) << std::endl; My understanding that in_event.buffer is a pointer-to-char, so that *(in_event.buffer) should be an unsigned char. I don't understand where I am doing wrong, I would be very grateful if someone could point out my error. Oh, my computer is Archlinux 64 bit using jack2-git 20120718. I have put up a git repo of the code on https://github.com/shanipribadi/pitch-segfault.git Thanks. Shani Pribadi