Specific notes act differently when legato is enabled

[audio2000]

I apologize if this has already been corrected, it seems that many Linux plugins that use Fluidsynth do not seem to keep up with updates of Fluidsynth itself.
If not, I may have found a possible bug if anyone is interested.
I also apologize because some of this may be difficult to explain well.

ISSUE TOPIC
When legato is enabled I noticed that two specific note overlaps that are notes side by side, seem to generate an almost portamento style effect compared to all of the other side by side legato notes tested.

HOW TO REPRODUCE
Legato is achieved when user holds down a note and then overlaps playing with another note.
The two specific note overlaps I notice this issue with are....
-when you hold down D and play the next note E
-when you hold down B and play the next note C
when you do this you almost hear more of a portamento kind of effect occurring, the notes are not as defined sounding as when you do this with other notes.
My tests were most often done using lower octaves of these notes D1 D2 D3 but I think I remember this occurring with the higher octaves of these notes as well.

To really hear this portamento kind of sound I am speaking of, you can hold down the first note (for example D) and then keep tapping and release next note (for example E).

This occurred with more than one soundfont so it does not appear to be instrument specific.

Again the unfortunate thing is that I cannot test newer versions of Fluidsynth at the moment. On top of that even if this is a bug and corrected as mentioned it does not seem like plugins update to newer versions, but figured if it is a bug I should mention what I have found, maybe could help others who have access to newer versions of Fluidsynth.

If anyone willing to try and verify if they could generate the same results, please mention it here.
If this is a bug if someone could move this over to the Issues section, or let me know and I can copy and paste it over if needed.

Thank You

[derselbst]

I am not using legato, portament, or poly / mono. But there is quite a lot documentation available here: https://github.com/FluidSynth/fluidsynth/tree/master/doc/polymono

And I'm pinging @jjceresa since he implemented it and might be able to provide a direct answer.

[audio2000]

Thank you for your reply.
Does not seem like that developer has been around for quite a few years now so does not look like he will be responding.
Not sure if you would be able to answer this, but do you by any chance know if those .txt files mentioned in the link you provided are the actual code used by Fluidsynth to make use of things like legato? Or are these .txt files more just informational and there is different actual code responsible for things like legato.

Thank you again for at least trying to contact that developer for me.

[derselbst]

The txt files are config files for fluidsynth's shell, this is not related to the actual implementation. The main part of the implementation is included here:
https://github.com/FluidSynth/fluidsynth/blob/master/src/synth/fluid_synth_monopoly.c

[jjceresa]

@audio2000

ISSUE TOPIC
When legato is enabled I noticed ....

Sorry, poly/mono works fine here, as described by FluidPolyMono-0004.pdf chapter 3.
So none of the issue you describe above can be reproduced.

Not sure if you would be able to answer this, but do you by any chance know if those .txt files mentioned in
the link you provided are the actual code used by Fluidsynth to make use of things like legato?

Yes, those .txt files are usable directly as described by readme.txt FluidPolyMono-0004.pdf chapter 3.1.
You need the fluidsynth console application. https://github.com/FluidSynth/fluidsynth/wiki/UserManual#shell-commands

I recommend using this tool while using any MIDI keyboard connected to fluidsynth. Option -d and -v will allow to be aware of MIDI messages send over your shoulder and received by fluidsynth.