[LAU] Weird behaviour with Calf Fluidsynth

[Bill Purvis]

On 06/02/2021 11:19, Edgar Aichinger wrote:
>
> > I raised a query on the Fluidsynth list, and they suggested trying with
>
> > the command-line
>
> > version of fluidsynth. I tried that and it responded as it should -
>
> > which suggests the
>
> > problem is in the Calf Gui. I guess I should raise it with the Calf 
> list
>
> > (if I can find it.)
>
> >
>
> > I assume that LV2 uses either Alsa or Jack to communicate, but I've not
>
> > used LV2 at all.
>
> > Certainly Fluidsynth, and hence Calf, is quite happy using Jack. I 
> don't
>
> > know about the
>
> > other Calf plugins, as I've never used any, other than the synth.
>
>
> I think I found the cause, LV2 version indeed is fine...  it's a 
> change in calfjackhost done in 2018:
>
>
> https://github.com/calf-studio-gear/calf/commit/1b37e753876fdd104a906aed1e712ff28ec4611f#diff-3fc4abf5e55f800decb309a734fcd5b32b519c7a3a8e8c7b973759593bf67009
>
>
> To me it looks that this commit is just plain wrong in raising the 
> channel number by one.
>
>
> The intent (see issue #97 referenced in this commit msg) is to 
> compensate the offset seen in calf monosynth and other synths, but 
> apparently this change simply increases the input buffer channel by one...
>
>
> So I changed line 197 in jackhost.cpp from:
>
>
>  int channel = (buffer[0] & 0x0f) + 1;
>
>
> to read:
>
>
>  int channel = (buffer[0] & 0x0f);
>
>
> and this fixes the off by one error in fluidsynth, and it seems the 
> other synths still respond on correct channels, even if displaying 
> 0-15 in their MIDI channel selectors.
>
>
> (tried with Mamba virtual keyboard on my laptop, which also displays 
> channels as 1 - 16)
>
Fine, I trust that will percolate through. For the moment I can live 
with it, I'd rather
not get into recompiling Calf, got enough on my plate...

Bill

-- 
+----------------------------------------+
| Bill Purvis                            |
| email: bill at billp.org                  |
+----------------------------------------+

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