Pitchbend midi resolution - nasty !

Angstrom · Post by **Angstrom** » Mon Dec 10, 2007 2:43 pm

I was checking a different bug and could hear pitch bend quantization so I took a look at the data as recorded into a midi clip from a roland controller keyboard.

you can see that it looks like a terrible staircase.

See that some polling steps are two sixteenths apart.

My midi interface is a Fireface 400 using the DirectX driver,
the keyboard is a Roland PC-180A.

Neither of which ought to contribute here. I get the same thing in Live 6.10

Does anyone else get this ?

longjohns · Post by **longjohns** » Mon Dec 10, 2007 3:20 pm

Sure, that doesn't surprise me, unfortunately.

I wonder if the keyboard modifier could work with MIDI signals, as it does when drawing with the pen tool? Not that you'd savor holding down a key semi-permanently

Poster · Post by **Poster** » Mon Dec 10, 2007 3:45 pm

as far as I experienced the rounding has always been a bit bad..

hoffman2k · Post by **hoffman2k** » Mon Dec 10, 2007 4:08 pm

Turn off MIDI thinning?

http://www.ableton.com/forum/viewtopic. ... 39&start=0

Poster · Post by **Poster** » Mon Dec 10, 2007 4:15 pm

hoffman2k wrote:Turn off MIDI thinning?

http://www.ableton.com/forum/viewtopic. ... 39&start=0

aah yes, ofcourse..

why is the rounding that bad by default again? forgot..

Angstrom · Post by **Angstrom** » Mon Dec 10, 2007 4:28 pm

I just tried

Code: Select all

-MidiEventThinning=0

and it is no different, like a broken staircase.
31 steps make an octave, lumpy!

Should I assume that everyone else has a nice smooth line when bending, unlike this?

hoffman2k · Post by **hoffman2k** » Mon Dec 10, 2007 4:29 pm

Poster wrote:
hoffman2k wrote:Turn off MIDI thinning?

http://www.ableton.com/forum/viewtopic. ... 39&start=0
aah yes, ofcourse..

why is the rounding that bad by default again? forgot..

Because Ableton likes debugging MIDI automation bug reports?
Like... Duh...

hoffman2k · Post by **hoffman2k** » Mon Dec 10, 2007 4:38 pm

Angstrom wrote:I just tried
Code: Select all
-MidiEventThinning=0
and it is no different, like a broken staircase.
31 steps make an octave, lumpy!

Should I assume that everyone else has a nice smooth line when bending, unlike this?

I guess we traded it off for the edit button.

Angstrom · Post by **Angstrom** » Mon Dec 10, 2007 4:48 pm

So, does anyone else see this awful staircase of one value change every 16th or 8th?

is it just my machine or is it Live ?

I mean what happened to 96ppqn ? With 96ppqn we should have 25 samples per 16th note,

What I have is one value change every sixteenth note, or sometimes one sample per 8th note. And when it does change it is a stair case not a ramp, I mean really, WTF !

Christ that's terrible, I mean , the terrible I could write better than!
Ableton are meant to be better at this than me. What are you using to take these things?
Windows timers ?

please say no, please say no, please say no.

in addition to the stop-start sample timing, why isn't the output smooth like this :

all I did there was delete duplicate values by hand.
Not hard programatically, but a real PITA to do it by hand.

if the duplicate values were removed at least it would play back reasonably correctly, instead of all lumpy.

Poster · Post by **Poster** » Mon Dec 10, 2007 5:02 pm

Angstrom wrote:So, does anyone else see this awful staircase of one value change every 16th or 8th?

is it just my machine or is it Live ?

can try later..

have you tried if a rotary is any different?
maybe your pitch wheel has a hick-up?

justin · Post by **justin** » Mon Dec 10, 2007 5:13 pm

nope, ur not the only one i get it too...

it sucks big time, it doesnt like it when u do fast pitch bends... seems to get stuck on half way occasionally... and i get the big chunky irregular steps...

as u point out, u can correct this manually but that is besides the point.

this has to be a bug, have u sent a msg to support?

specs: live 701 / osx 10.4.11 / remote sl 25

PS. (if anyone from ableton reads this) bezier curve automation is very useful with pitch bends - HINT HINT

Angstrom · Post by **Angstrom** » Mon Dec 10, 2007 5:40 pm

hmm, something weird here.
I still get stepping on other hardware controllers such as the pathetic little 'volume' slider on this Roland, but the stepping is at least more frequent
this is what a BCR pot displays. steppy, with duplicate values, but at least it is detailed.

So Live is rocording that at a reasonable rate - even if it isn't being very sensible about the data.

On another angle of attack :
I took a look at the polling values of the pitch bend,, how often it is reporting to the interface (not in Live) and I'm not particularly impressed.
It only seems to report whenever the MSB value changes, so although it is supposedly 16384 values, I am only getting 64 of those 16384.

I'm just baffled now

I am not sure whether it has become broken , or if it has always been shit.

I need to get my big fat master keyboard out of storage I think

hoffman2k · Post by **hoffman2k** » Sun Feb 03, 2008 11:57 pm

It does raise an interesting question though.
I know Machinate did some work on the Pad Kontrol knobs with his hack, so that the values would come out smoother.
I remember some other controllers where pitchbend and such was bollocks within the unit itself. Edirol comes to mind..

So the next step would be to record a smooth line into Live and see what it fetches.
I'll check it out tomorrow. Just came back from a flight and one of my ears has yet to pop...

Angstrom · Post by **Angstrom** » Mon Feb 04, 2008 12:06 am

actually - that's a good idea - route some smooth pitchbend action looped-back into another track and see what results

Poster · Post by **Poster** » Mon Feb 04, 2008 12:13 am

does the PB-Range on the controller have anything to do with this?

if you translate 5 octaves to whatever the bit resolution of that PBW is,
rough stepping can be expected..

just a thought..