Re: MIDI (was Re: [Denemo-devel] Anacrusis script needed)

[Richard Shann]

On Mon, 2009-09-14 at 11:57 -0500, Jeremiah Benham wrote:
> On Mon, 14 Sep 2009 16:51:23 +0100
> Richard Shann <address@hidden> wrote:
> 
> > On Mon, 2009-09-14 at 14:39 +0100, Richard Shann wrote:
> > > There is some investigating still to do - why does it repeat noteon
> > > madly if no noteoff is given etc, but it seems usable. I don't
> > > understand all the stuff about nframes etc there is a loop which is
> > > is going thru
> > >   for(n=0;n<nframes;n++){
> > > in send_midi_event which can only fire once - also i is just a
> > > synonym for 0 here...
> > > 
> > OK, I have looked at this. The loop is spurious, and puts the noteon
> > message in multiple times, which is what you hear if your noteoff is
> > not scheduled for 44 seconds. The noteon is being put as having a
> > time n, by this
> > 
> >     buffer = jack_midi_event_reserve(port_buffers[i], n, 3);
> > 
> 
> I tried that but it did not work.
hmm, I have the duration reduced to 100ms though, so perhaps that is why
it is working for me. In fact I have the following now:

static void
send_midi_event(jack_nframes_t nframes){
  unsigned char *buffer;
  gint n;
  void *port_buffer;

      if (output_ports[0]){
        port_buffer = jack_port_get_buffer(output_ports[0], nframes);
        jack_midi_clear_buffer(port_buffer);
        if (BufferEmpty==FALSE){
          buffer = jack_midi_event_reserve(port_buffer, 0, 3);
          if (buffer == NULL) {
            warn_from_jack_thread_context("jack_midi_event_reserve failed, NOTE 
LOST.");
            return;
          }
          buffer[0] = global_midi_buffer[0];
          buffer[1] = global_midi_buffer[1];
          buffer[2] = global_midi_buffer[2];
          BufferEmpty=TRUE;
          warn_from_jack_thread_context("Setting TRUE\n");
        }
      }
}

This has the jack_midi_clear_buffer done regardless of whether we have
new data for it - if it still contains the old data that could explain
the repeated notes.
This is working fine for me - I haven't tried the 44 second note though.
Can you try this?
Richard


>  Through trial and error I have only
> found that this works:
> 
> 
> static void
> send_midi_event(jack_nframes_t nframes){
>   unsigned char *buffer;
>   gint i=0;
> 
>   void *port_buffers[MAX_NUMBER_OF_TRACKS];
>   if (global_midi_buffer[0] >=0){
>      if (output_ports[i]){
>      port_buffers[i] = jack_port_get_buffer(output_ports[i], nframes);
>      jack_midi_clear_buffer(port_buffers[i]);
>      buffer = jack_midi_event_reserve(port_buffers[i], 0, 3);
>      buffer[0] = global_midi_buffer[0];
>      buffer[1] = global_midi_buffer[1];
>      buffer[2] = global_midi_buffer[2];
>      global_midi_buffer[0] = 0;
>      BufferEmpty=TRUE;
>    }
>   }
> }
> 
> I have removed the loop even though it was not causing it. Was I
> believe was causing it was the BufferEmpty even though it was set to
> static volatile gboolean.
> 
> >  we only want to put it in at time 0. 
> > 
> > Shall I check something in along these lines?
> 
> I would say no unless you have tested it and it works.
> 
> Jeremiah 
> 
> > Richard
> > 
> > 
> > 
> > 
> > _______________________________________________
> > Denemo-devel mailing list
> > address@hidden
> > http://lists.gnu.org/mailman/listinfo/denemo-devel
>