[LAD] Segfault when trying to dereference __midi_event.buffer (c++ newbie question)

[hermann meyer]

Am 21.11.2012 13:24, schrieb SxDx:
> ----- Original Message -----
>> From: "Shani Hadiyanto Pribadi"<shanipribadi at gmx.net>
>> 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);
>> }
> jack_midi_event_get may return ENODATA
> as explained in {wherever}/include/jack/midiport.h
> don't access in_event in that case, there is no data
> _______________________________________________
here is how we access jack_midi in data.

// ----- jack process callback for the midi input
void MidiControllerList::compute_midi_in(void* midi_input_port_buf) {
     jack_midi_event_t in_event;
     jack_nframes_t event_count = 
jack_midi_get_event_count(midi_input_port_buf);
     unsigned int i;
     for (i = 0; i < event_count; i++) {
         jack_midi_event_get(&in_event, midi_input_port_buf, i);
         if ((in_event.buffer[0] & 0xf0) == 0xc0) {  // program change 
on any midi channel
             gx_system::atomic_set(&program_change, in_event.buffer[1]);
             pgm_chg();
         } else if ((in_event.buffer[0] & 0xf0) == 0xb0) {   // controller
             set_ctr_val(in_event.buffer[1], in_event.buffer[2]);
         }
     }
}