Re: [Linuxsampler-devel] cancel release on note on?

[Mark K. <mar...@gm...>]

On Sun, 05 Dec 2004 19:01:28 +0100, Andreas Persson
<and...@lk...> wrote:
> Mark Knecht wrote:
> 
> >    Speaking logically only, and not musically or even about GSt or LS
> > specifically, I think it depends on what sort of instrument you are
> > modeling.
> 
> Yes, I guess that's why the "Piano release mode" in a gig file is optional.
> 
> > If the instrument is something physical where-in the second
> > event uses the same physical entity to make the sound, then the second
> > event should override the first. The quiet note replaces the loud
> > note. This is the way a synth with limited oscillator count would work
> > and probably the way GSt works when doing voice stealing.
> 
> If there are enough voices, GSt will play the release of the loud note
> along with the quiet note.
> 
> 
> 
> >    However the piano is difficult. Playing a second note on middle C
> > does not eliminate the first note. (sustain pedal held) The second
> > note is additive, and additive in a non-intuitive way. Actually,
> > whatever the effect of the first and second events are, I would say
> > they both end at the same time. (Again, sustain pedal held.) I don't
> > think the loud note finishes any sooner than the soft note, does it?
> > In fact the soft note might actually finish sooner implying velocity
> > effects the overall length of the envelope.
> 
> Just to be sure, note that the case we've been discussing is not when
> the sustain pedal is being held. Instead: The second note comes so close
> to the note-off of the first that the first note has not finished its
> release yet. Then, with current LS, the first note will give up its
> release and continue to play at its current volume together with the
> second note.

OK, I think I missed that. With a piano this window of time is pretty
small. I guess what you are talking about really is a bug if it does
what I think you are saying it does. The first note must just die away
or you run out of notes much more quickly.

The part I'm not sure I understand from this email is whether the
first note is still using it's sample base, or did it start using the
second note's sample base? Clearly it must use its own samples since
it may be from a different velocity group. I think it probably does.

> 
> When the sustain pedal is held, I think both GSt and LS will handle all
> note-on events as separate events that run independently until their
> respective samples finish (or the sustain pedal is released). An
> exception to this is if "Self mask" option is enabled. Then, a louder
> note will kill a playing quiet one, to preserve polyphony. This feature
> is not yet in LS.

I think that possibly LS should try to improve on GSt's usability. I
run into problems with GSt all the time where the addition of notes
causes the overall mix to get to loud and hence it distorts. This
doesn't happen as quickly when you mix loud and soft notes, but if you
mix all loud notes then you end up with too much volume and the mix
bus distorts. (numerically)

Possibly some sort of soft compressor in the output stages of LS would
help a lot in this area.

> 
> The non-intuitive addition you mention, was an interesting thought. I
> don't think GSt has any support of it.
> 

Actually I had a much more radical thought about what the 'right' way
to do some of this when we are talking about piano modeling. Again, my
thinking initially was about the case where the sustain pedal is held,
but some of it applies even without sustain.

If we consider the piano where there is only a single middle C element
(1 or more strings struck together) then I think a couple of things
possibly happen:

1) Since there is only one string to vibrate then there is only one
'sample set' to play? Maybe a soft second note is really just a
modification of the existing (louder) note's envelope? I'm not totally
convinced of this since the second soft note may have significant
harmonics in it's initial samples that we wouldn't want to miss, at
least in certain cases.

2) Even if you decide that there is a second sample set to play, in
the real piano the two must be sync locked to each other. The string
is vibtrating and the second strike (or probably more accurately the
lower volume strike) must get in sync with the first (louder) strike.
I.e. - there is only one way to vibrate the string at that frequency.
Since both strikes account for creating the same frequencies. (I
think...)

Point in case. Hit a note at 500Hz. Hit the same note exaclty 1 second
later. Numerically the two would cancel each other. The first is going
up while the second is going down, in sine wave terms. In the piano
they do not. The second note always adds to the mix. So, either the
first note gets synced to the second or the second to the first, but
something must be happening physically.

Is there an opportunity to make a better sounding LS by addressing
this idea somehow?

- Mark