Re: [fluid-dev] New patch: polyphonic key pressure (aftertouch)

[Kjetil Matheussen]

On Tue, May 23, 2017 at 1:32 PM, Marcus Weseloh <address@hidden> wrote:

Hi,

2017-05-23 13:07 GMT+02:00 Kjetil Matheussen <address@hidden>:

Great work! I've been meaning to implement this myself for many years but never got started. I'm going to apply your patch to the fluidsynth in Radium, since it has good support for polyphonic aftertouch, and see how it works. If it works, I'm going to keep it in the next release of Radium.

Excellent, would be great if you could give it a good round of testing!

One thing I wasn't quite sure about is how exactly the aftertouch is supposed to behave for a note that isn't currently playing, or after a note_off event. Either it's not specified or I missed it in the MIDI spec... 

So what my patch does is the following: polyphonic aftertouch is always accepted on any available channel and note value. The value is stored even if that particular note is currently not playing. And the aftertouch value is retained on note_off. That of course puts the responsibility of resetting aftertouch between notes onto the MIDI controller... but it also gives it much more flexibility and avoids hard-coded behaviour that might not be suitable for every MIDI controller type.

Does anybody know if that behaviour is correct according to the specification (if there even is one)? Or do other samplers do it differently and we should just follow a common practice?

So when fluidsynth receives these bytes:

0xa0 0x60 0x10

0x90 0x60 0x70

Is the note played with a volume value of 0x10?

In case, that doesn't seem right...