[LAU] Fluidsynth shift an octave down

[Pedro Lopez-Cabanillas]

On Tuesday 11 January 2011, you wrote:
> On Thu, Jan 06, 2011 at 02:09:27PM +0100, Pedro Lopez-Cabanillas wrote:
> > On Thursday 06 January 2011, Ken Restivo wrote:
> > > Is there a way in fluidsynth to shift a whole soundfont up or down an octave?
> > > 
> > > Or would I have to edit the soundfont in Swami and permanently move the notes around?
> > 
> > You can use FluidSynth's MIDI router. For instance, type the following commands in FS' shell:
> > 
> > router_clear
> > router_begin note
> > router_chan 0 8 1 0
> > router_par1 12 127 1 -12
> > router_end
> > 
> > It transposes notes in channels 1 to 9 one octave down. See also: http://sourceforge.net/apps/trac/fluidsynth/wiki/UserManual#MIDIROUTER
> > 
> 
> I tried this, and it did indeed shift the notes an octave down, but, it broke fluidsynth so that it doesn't respond to Volume or Expression CC's anymore!
> 
> Is that a bug in Fluidsynth or am I doing something wrong?

This is the expected behavior. In FluidSynth, "router_clear" deactivates *every* event, not 
only volume or expression controllers. I mean that after the following commands:
 
router_clear
router_begin note
router_end

FluidSynth will recognize notes, but not controllers or program changes, or any other message types. To activate controllers again, you need to execute the commands:

router_begin cc
router_end

The same for program changes. You can restore them again with:

router_begin prog
router_end

Complementary of router_clear is the command "router_default", that reassigns all the initial defaults (losing your custom rules).

Regards,
Pedro