27 Oct
2003
27 Oct
'03
6:50 a.m.
Hi,
I was wondering what's the correct way to handle the sustain pedal when
implementing a MIDI sound generating module.
from the MIDI specs:
-----------
Hold Pedal, controller number: 64:
When on, this holds (ie, sustains) notes that are playing, even if the
musician releases the notes. (ie, The Note Off effect is postponed until
the musician switches the Hold Pedal off). If a MultiTimbral device,
then each Part usually has its own Hold Pedal setting.
Note: When on, this also postpones any All Notes Off controller message
on the same channel.
Value Range: 0 (to 63) is off. 127 (to 64) is on.
--------------
My question is about ".... holds (ie, sustains) notes that are playing,
even if the musician releases the notes."
Assume I play a chord, press the hold pedal, which causes the notes to
be sustained. When I play new notes those are sustained too.
So far so good.
The question arises when I press the same key two times.
Assume no sustain pedal for now.
When I press C2 I hear the note. When I release it the sound does not
vanish immediately but takes a small amout of time to decay due to the
release envelope. If after releasing C2 I immediately press C2 again I
hear two C2 notes for a brief time.
Now same situation as above but with the sustain pedal pressed.
You hear the first C2, release it (the corresponding note-off is
postponed) and then press C2 again.
In that case is it correct that you must hear two sustained C2 notes.
Or must the first C2 be forced to get faded out / muted ?
If not (eg you hear two sustained C2 notes), how far can this go ?
Can there be 3, 4 etc sustained notes on the same key too ?
While I am not a piano player,common sense says me thatpiano has only
one string per key so IMHO it would sound unnatural to play two
notes on the same key.
As you might have guessed I ask this stuff because we want to add
support of sustain in linuxsampler.
thanks for your infos.
PS: a new CVS repository for linuxsampler is up: cvs.linuxsampler.org
interested developers and users please check it out and give us feedback
via our mailing list.
(subscription infos at http://www.linuxsampler.org ).
cheers,
Benno
http://www.linuxsampler.org
27 Oct
27 Oct
8:44 a.m.
On Mon, Oct 27, 2003 at 12:44:45PM +0100, Benno Senoner wrote:
Assume no sustain pedal for now.
When I press C2 I hear the note. When I release it the sound does not
vanish immediately but takes a small amout of time to decay due to the
release envelope. If after releasing C2 I immediately press C2 again I
hear two C2 notes for a brief time.
Now same situation as above but with the sustain pedal
pressed.
You hear the first C2, release it (the corresponding note-off is
postponed) and then press C2 again.
In that case is it correct that you must hear two sustained C2 notes.
Or must the first C2 be forced to get faded out / muted ?
If not (eg you hear two sustained C2 notes), how far can this go ?
Can there be 3, 4 etc sustained notes on the same key too ?
Most synths will just restart the note on the same voice in both cases,
i.e. begin a new attack phase at the level the previous (same) note had
reached during its release. So there will one be at most one note of a
particular pitch at the same time.
Small pedantic note: a piano has more than one string per note, but
you always play them all together :-) It's one of the reasons why a
decent piano sound is quite hard to synthesize.
--
11:06 a.m.
Alfons Adriaensen wrote:
On Mon, Oct 27, 2003 at 12:44:45PM +0100, Benno Senoner
wrote:
Keep in mind that linuxsampler streams its samples from disk so we can
use very large sample sets.
There exist many high quality piano samples in .GIG format that have 4-8
layers (velocity splits) for
pedal up and pedal down samples.
My question is mainly how to switch these samples.
What do you mean with "i.e. begin a new attack phase at the level the
previous (same) note had
reached during its release" ?
You mean velocity level ?
Assume I press C2 with velocity 50 pedal up, the C2-pedalup (associated
to velocity 50) sample sounds.
Now I press the sustain pedal and press C2 with velocity 100.
What should the sampler do ? Quickly fade out the C2-pedalup
(velocity-50) note and trigger the
C2-pedaldown (velocity 100) note ?
And of course when you release the pedal all sustained notes will get a
note-off.
for example I ordered the PMI Steinway D Grandioso sample (5 GB of
piano samples) in .GIG format
(see here for an mp3 demo, description etc:
http://www.timespace.com/data/downloads/itemdetail.asp?ID=1133 )
and I want that this library plays perfectly in linuxsampler thus we
need some inputs for good sustain pedal
implementation.
As said we are not talking about string resonance emulation (yet), we
just want those wonderful sample libs
to play correctly in linuxsampler and this includes correct (withhin the
limits imposed by sampling) correct
sustain pedal emulation.
----
from a a review in SoS:
http://www.soundonsound.com/sos/oct02/articles/sample_grandioso.htm:
One of the features that adds extra realism to Steinberg's /The Grand/
VST Instrument is its ability to crossfade between the sustain pedal up
and down samples when you press and release the sustain pedal. While
it's not currently possible to do this with /GigaStudio/, PMI will
overcome this with a clever utility called /Virtuoso/, which provides
the same functionality in /GigaStudio/ when combined with the /Virtuoso/
patches in the library. I say 'will' because although the /Virtuoso/
patches are supplied, the /Virtuoso/ utility itself isn't ready yet.
----
Is that feature called "re-pedaling" ?
IMHO it would be pretty easy to implement if you always start both
samples (pedal-up and pedal-down) and then
crossfade between the two when the user presses the pedal. (besides from
the fact that you need to defer note-offs
the pedal is down).
Or does that sound bad ?
The more and better inputs you will give us about how to implement
sustain the more likely linuxsampler will
implement it correctly.
Assume no sustain pedal for now.
When I press C2 I hear the note. When I release it the sound does not
vanish immediately but takes a small amout of time to decay due to the
release envelope. If after releasing C2 I immediately press C2 again I
hear two C2 notes for a brief time.
Now same situation as above but with the sustain
pedal pressed.
You hear the first C2, release it (the corresponding note-off is
postponed) and then press C2 again.
In that case is it correct that you must hear two sustained C2 notes.
Or must the first C2 be forced to get faded out / muted ?
If not (eg you hear two sustained C2 notes), how far can this go ?
Can there be 3, 4 etc sustained notes on the same key too ?
Most synths will just restart the note on the same voice in both cases,
i.e. begin a new attack phase at the level the previous (same) note had
reached during its release. So there will one be at most one note of a
particular pitch at the same time.
Small pedantic note: a piano has more than one string
per note, but
you always play them all together :-) It's one of the reasons why a
decent piano sound is quite hard to synthesize.
Yes string resonance is the problem and not trivial to emulate (eg GEM
RealPiano and The Grand VSTi perform some
kind of emulation), but for now let's focus to good playback of these
high quality multi GByte instrument libraries.
Then if some skilled DSP developers want to join our quest and add
string resonance (like The Grand VSTi does) then
even better.
cheers,
Benno
http://www.linuxsampler.org
A professional grade sampler for Linux
1:39 p.m.
On Mon, Oct 27, 2003 at 05:00:55PM +0100, Benno Senoner wrote:
I was thinking in terms of synthesizers using an envelope generator - not
playing samples.
I case a same note is played again while the pedal is on, I'd start
the new one and quickly fade out the old one at the same time.
But if the second one is softer than the first, the resonances of
the other strings will change too, if they are in the same sample
stream as the played note.
Alfons Adriaensen wrote:
Most synths
will just restart the note on the same voice in both cases,
i.e. begin a new attack phase at the level the previous (same) note had
reached during its release. So there will one be at most one note of a
particular pitch at the same time.
Keep in mind that linuxsampler streams its samples from disk so we can
use very large sample sets.
There exist many high quality piano samples in .GIG format that have 4-8
layers (velocity splits) for
pedal up and pedal down samples.
My question is mainly how to switch these samples.
What do you mean with "i.e. begin a new attack phase at the level the
previous (same) note had
reached during its release" ?
You mean velocity level ?
Assume I press C2 with velocity 50 pedal up, the C2-pedalup (associated
to velocity 50) sample sounds.
Now I press the sustain pedal and press C2 with velocity 100.
What should the sampler do ? Quickly fade out the C2-pedalup
(velocity-50) note and trigger the
C2-pedaldown (velocity 100) note ?
And of course when you release the pedal all sustained notes will get a
note-off. One of the features that adds extra realism to
Steinberg's /The Grand/
...
Is that feature called "re-pedaling" ?
IMHO it would be pretty easy to implement if you always start both
samples (pedal-up and pedal-down) and then
crossfade between the two when the user presses the pedal. (besides from
the fact that you need to defer note-offs the pedal is down).
Or does that sound bad ?
Fascinating problem :-) Cross-fading between two sample streams will be
audible if the phases of at least the fundamental and the strongest
harmonics are not the same in both streams. Maybe you will have to track
the phase of both streams in order to find the right places to x-fade...
Considering both cases, what you really need is a sample streams with only
the resonance sound for all notes at different velocities. These would then
pile up as long as the pedal is held...
--
FA
7693
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7693
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linux-audio-dev@lists.linuxaudio.org
3 comments
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participants (2)
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Alfons Adriaensen -
Benno Senoner