Re: [Qtractor-devel] It's me again :)

[Will G. <wil...@mu...>]

On Sat, 25 Apr 2015 13:34:59 +0100
Rui Nuno Capela <rn...@rn...> wrote:

> On 04/25/2015 11:49 AM, Will Godfrey wrote:
> > I'm curious as to how qtractor handles LV2 synths. When trying to use yoshimi
> > as a plugin I again don't seem to have NRPNs responding, although they now
> > behave quite correctly in standalone form. Surely there should be no
> > difference. As far as I can tell (in yoshimi) the same code is used for both.
> >
> 
> afaict. there might be a difference: LV2 (and VSTi) plugins get the 
> (N)RPNs always as a de-composited sequence of the regular 4 MIDI CC 
> events, instead of a single ALSA-sequencer composite event 
> (SND_SEQ_EVENT_REGPARAM, SND_SEQ_EVENT_NONREGPARAM). otoh. DSSI plugins 
> get the later ALSA-seq single event form though.
> 
> cheers

Hmmm, I think I may have an idea what's causing the problem. When you unpack
the NRPM what order do you send the bytes in?

In yoshimi, as soon as we get an NRPN change, the data CCs are disabled,
cleared, and only re-enabled once a valid command has been received.

Also, we use the data MSB as a command sub level (other synths do this too),
which then lets us send running bytes to LSB. We do this to simplify things for
users, and to minimise MIDI traffic.

P.S. while searching the 'net for MIDI info I came across the following
comment :)

New Book out! 101 ways to do NRPN - all of them wrong.

-- 
Will J Godfrey
http://www.musically.me.uk
Say you have a poem and I have a tune.
Exchange them and we can both have a poem, a tune, and a song.