Re: iPhone AU best practices
Re: iPhone AU best practices
- Subject: Re: iPhone AU best practices
- From: Admiral Quality <email@hidden>
- Date: Wed, 16 Jun 2010 18:35:23 -0400
On Wed, Jun 16, 2010 at 6:00 PM, Urs Heckmann <email@hidden> wrote:
>
> Am 16.06.2010 um 20:47 schrieb Admiral Quality:
>
>> That would be a pretty strange MIDI controller to produce that stream.
>> In real life, it simply doesn't come up.
>
> Actually, it happens quite often when a synth reacts to more than one source of input. E.g. if someone plays a synth live while it's also played by a midi sequencer. There have been "MIDI Merge Devices" right from the beginning of MIDI, and these have occasionally cause trouble. Even though it's relatively easy to count NoteOns and NoteOffs.
Hey Urs.
MIDI Merge... yes, more witchcraft. ;) But weren't those really more
intended to merge controllers *on different channels* into a single
cable? For back in the days when your hardware sequencer only had one
MIDI input jack? Did people really use them to merge MIDI on the same
channel? (While I've been MIDIing since 1983, I never had want nor
need for a merge box.) Merging on the same channel seems SUCH a bad
idea!
Yes, if MIDI had been a smarter protocol it wouldn't describe keystate
changes, but rather note events. But if you stay away from the crazy
what-if scenarios, keystate actually works quite well for most every
real-world instrument, and even written notation -- at least for a
single part within a score. (By the way, is there a way in traditional
notation to specify, for instruments that are capable of it, that you
want 2 or more of the same note played at the same time? For example
guitars can often sound 2 of the exact same note. Do they notate that
or is voicing left up to the player?)
>
> The iPhone is a multitouch device. It might easily happen that two fingers end up bumping into the touch sensible area of the same key. Depends on the size of the finger I guess, but it's perfectly possible to presss the same key twice on the iPhone - whereas you couldn't do that on a real life piano. Now, think of an app that's blown up to fit the screen of an iPad. Now you can sink 11 fingers on a single key 8-))
>
Still I'd think (and again I'm only assuming here) that your button
object or whatever it is that gets "pressed" has it's own up/down
state. And if not, that you'd want to code that into your *interface*
rather than the tone generator, so that the same "pad" can't be
pressed again before being released. Or actually what would be better
is if an overlapping trigger of the same pad area caused an off/on to
be sent -- then you wouldn't inhibit the ability to perform fast
"rolls" by needing to lift one finger before the next one hit.
OP was also wondering about worst case of "10 fingers". But isn't
there a limit to how many simultaneous multi touch points are
possible?
Anyway, we all know the real problem isn't so much "how many fingers
are down" but rather the fact that many sounds will continue to sound
during their "release stage" after the triggering object has been
released. A quick gliss across a virtual keyboard with a long
sustaining sound could get a whole bunch of voices going.
> Back OT: I think it's perfectly valid to reset the voice of a certain note when it's "pressed again". You still need a counter though to release the note on the last corresponding NoteOff.
>
Absolutely. Cycle assignment mode was/is relatively rare feature, but
OP asked about it so I thought I'd offer a bit of history. (I remember
I could make my old Roland JX-3P do cycle assignment by powering it on
while holding a certain button down, an "easter egg" secret feature.
:)
I'm not saying any of this stuff is impossible or could never
conceivably happen. I'm just trying to throw in a vote for sanity. My
recommendation would be make the GUI only send one of each note at a
time, and then build a traditional polyphonic voice assigner that
listens to that.
- Mike/AQ
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