Re: [fluid-dev] Short note durations on percussion channel

[josh]

I had a brief look over TiMidity++ code.  The license is GPL and  
therefore not compatible with FluidSynth, so its just for reference..   
I have up until now not really looked much at TiMidity++.  It looks  
really powerful and seems to emulate tons of different synthesizer  
modules and what not.  I don't think we should even try to compete in  
that area with it!  The number of processed SYSEX messages is  
enormous.  FluidSynth probably has its own niche, though I'm not  
really sure what exactly it is, perhaps someone else has a better  
overview of both of them.  FluidSynth is embeddable and probably a lot  
simpler.  I think we should focus on it being a good general purpose  
SoundFont synthesizer, but not get too bogged down in faithfully  
synthesizing every MIDI file out there.

At any rate.  It seems that it has a mode parameter, such as we have  
been discussing, as well as a percussion channel map.  Note-offs are  
indeed ignored for non-looped percussion instruments.  If that is the  
proper behavior with GM/GS, I think we should follow it, but only if  
GM or GS mode is enabled.

I'm not really interested in getting too involved in the whole  
GM/GS/XG mess.  Because it is indeed a mess and I'd much rather move  
on to more interesting tasks :)


Quoting David Henningsson <address@hidden>:
> S. Christian Collins skrev:
> > My 2 cents: I'm pretty sure the Creative synths don't ignore note-off,
> > and I don't think it's necessary, because this should be taken care of
> > in the SoundFont design, IMO.  In the SoundFont's percussion bank, the
> > release phase of each sample allows the drum to be sustained even when
> > the note is released very quickly, and this is how GeneralUser GS and
> > pretty much every other GM bank behaves.
>
> As I said in a comment to http://fluidsynth.resonance.org/trac/ticket/1
> , the problem is that we never get through the attack phase. So I still
> think delaying the note-off could be a good workaround. But Christian
> could perhaps suggest a good default value for the delay?


I don't really like that solution, since it isn't really the defined  
behavior for GM/GS and the delay would be awkward to get right with  
different SoundFont files.


> > > Perhaps something like this would be adequate:
> > > midi.mode = raw, gm, no-off-percuss
> > > raw: Don't do any special percussion channel handling
> > > gm: Ignore note-offs for all but fast Whistle and Guiro on percussion
> > > channel
> > > no-off-percuss: Ignore all note-offs on percussion channel
>
> Assuming midi.mode (or better, synth.midi-mode) will be used to change
> between gm, gs, xg etc, it does not make sense to add no-off-percuss to
> that series since it might control more things (e g ignore bank
> selection in GM mode).
>
> Better to use a separate setting for this problem then, something like
> synth.note-off-percuss=delay/ignore/process. And for now, hardcode
> percussion channel to 10 (as already done in a few places).

Yeah, true.  I started off having it just be a value for something  
like note-off-percuss, but changed it when I started to consider a  
MIDI mode parameter as a good idea, which is the reason why it was a  
little convoluted.  Lets just add a synth.midi-mode parameter with the  
options: plain, gm, gs and xg and SYSEX message handling for entering  
and exiting those modes.  We should perhaps have a way for the user to  
override the mode though and not allow SYSEX changes.

> // David

Josh