jack_umidi - jack_midi_event_get() failed, lost MIDI event

[Clemens Ladisch]

Marcel Bonnet wrote:> Hello.
> I wrote a program to send System Exclusive Messages to my Roland XP-30
> Keyboard. This program (QStage) connects to jack_umidi .
> I send  a burst of 4296 events every time I load a sysex file.
>
> My program does not print "NOTE LOST", so I suppose that "maybe" I am using
> the API correctly. But jack_umidi is zombiffied DPRINTing hundreds times
> the same error  only after I load the second or third sysexfile (even if
> its the same file).
>
> "umidi_write:160: jack_midi_event_get() failed, lost MIDI event."

What timestamps (sample offsets) are you using?

Jack is all about sample-accurate event timing, so I suspect that events
get lost because they cannot be transmitted at what Jack thinks is the
desired time.

> I started jackd with a Midi BufSize > 4296 * 4 bytes

If you take care that events are not queued faster than they can be
transmitted (about 3125 bytes/s), the buffer size should not matter.


Regards,
Clemens