Re: Development Question

[Pieter Palmers <pieterp@joow.be>]

M. Gagnon wrote:
> Hi, i am now trying to port an application to linux using Alsa. At some 
> point, i have midi bytes as char* and i have to play them. This is exactly 
> the same data you'd find in a file, expect that it's in memory instead. How 
> is that possible?
> 
> If this is not possible, i could always take any help on playing midi using 
> sequencers I looked at the docs, i found a few samples, but they seemed to 
> be outdated and the one that could interest me segfaulted. After i debugged 
> it and fixed the segfault, it played nothing... (and i'm sure my midi is 
> configured correctly BTW, pmidi works and i also succeeded in getting single 
> notes to play)
This is how I do playback in the freebob backend for jack:

for (s=0;s<samples_read;s++) {
   signed int *byte=(buff+s);
   snd_seq_event_t ev;
   if ((snd_midi_event_encode_byte(
          port->parser,(*byte) & 0xFF, &ev)
        ) > 0) {
       // a midi message is complete, send it out to ALSA
       snd_seq_ev_set_subs(&ev);
       snd_seq_ev_set_direct(&ev);
       snd_seq_ev_set_source(&ev, port->seq_port_nr);
       snd_seq_event_output_direct(port->seq_handle, &ev);			   }
}

you can check the freebob_driver_midi_* functions in the freebob jack 
backend for more detail.

Pieter


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