Latency and MIDI

bruper

Hello,

by chance I was also testing midi today, driven from a MAudio 49E.
I've being trying to put in practice an idea I've being playing in my head from some time.
I notice that the latency in Isadora (2.01) is much greater (not only with an open scene and some actors, but also with no scene and just the monitor open) than Midi Monitor, OSCulator or SimpleSynth.
Why is this happening?

thanks for any information

mark

Dear @Rabadler + @bruper,

Well, there were have been no modifications at all to the MIDI code in ages, but I will investigate this to see if I can find something. I don't have a MIDI controller with me at the moment, but I will check this evening.

I just checked with a virtual MIDI connection and response was nearly instantaneous, as I would expect it to be.

But to be clear, when you all say latency, what are we talking about here? 1mS? 5mS? 100mS? It would be good to have some notion of what you mean.

Best,

Mark

Rabalder

For me its about 150ms.

mark

OK. That definitely doesn't match what I'm getting here. Are you connected to a video projector? Or just outputting to your screen?

Rabalder

Same result either way.

(the latency test file you attached showed responses down to 2ms though)

But I do have a max/msp patch running at the same time that converts piezo inputs to MIDI along with som other stuff. No image processing or anything heavy on the cpu.

I need the max patch running to convert drum strokes to midi, so Im not really able to test without max... The idea is that all audio(external hardware) and visuals change when I hit the drum.

mark

And drums, of course, being the worst case scenario when it comes to noticing latency. ;-) Anyway... will check.

Rabalder

haha.. yes. They are definitely an enemy of latency :)

bruper

@Mark

in my case the latency in Isadora 2 is quite noticeable (I have not tried with previous versions), i don't know how I would possibly measure the difference with Midi Monitor, OSCulator or SimpleSynth... but visually it looks like a second...(?) maybe i should video-record the monitor?

mark

Let me look into all of this you guys. I'll be back with more information today.

-- Mark

mark

Dear @bruper + @Rabalder,

Well, I guess I don't know what the problem is. Please view the movie at http://troikatronix.com/files/latency-test.mov

This was captured with a screen capture app. I'm capturing video from the FaceTime internal web cam at 640x360\. This is then fed to a duplicate of Rabalder's patch illustrated above. I am using a Korg nanoKontroller with a Control Watcher to trigger Random actors via MIDI.

I pressed the button really hard so that the microphone would pick it up -- so that sound is your reference for the trigger. As you can see, there is very, very little latency.

Are you guys feeding the virtual MIDI input with the output of, let's say, Ableton or some other software else that's producing millions of MIDI messages? Maybe I could see the delay then -- if you were just completely overloading the MIDI input buffer with data.

And also: what's the frame rate and cycle rate, shown in the bottom left corner of the main Isadora window?

There's got to be something else going on that's causing this.

Best Wishes,

Mark

Rabalder

First of all, thanks A LOT for all your responses. Youre really a great guy Mark!!

I dont have my rig fully set up right now, but I will in a couple of days. Then Ill do a propper test with a stripped down version of my max/msp patch with MIDI being sent only to isadora on various channels.(and other things I might think of..).

(My frame rate is 25, and cycle rate +/- 230.)

Ill post here when Ive done some testing.

mark

@Rabalder,

I try, I try. ;-)

But listen: the best thing you can do is to connect your Max patch into MIDI Monitor. (Free from snoize I think... search Google.) Just make sure there isn't some flood of data coming out that would clog Isaodra's pipes.

Your frame rate and cycles are good... so that's not the issue.

OK. Let me know what you find out.

bruper

Dear @Mark,

thanks for following this, totally agree with Rabalder !!
My fps 24.5 to 25 (25 in my preferences), my cycle rate between 190 to 225
Today I received my new Korg nanoKontrol2 and I just tried it:
Must say that it is spot on, no visible latency with Isadora.
PS: Actually doing additional tests, I notice that turning on the output port of Communication/Midi Setup did for a while somehow slow down the Midi input signal but went back to unnoticeable.
Connecting again the keyboard I fund that tonight there is no latency any longer.
Don't know what to say... Will have to do more tests
Best regards

mark

Well, both of your experiences were obviously real. Let's see if we can get to the bottom of it. Again, check the MIDI you are sending into Isadora with MIDI Monitor. Make sure there is not some surprising amount of messages coming from somewhere you didn't expect.

thyeks

Hello I have the same problem

Mac OS X 10.10.3 - Isadora 2.0.5.

My patch is a Picture player into a Kaleidoscope into a Projector

I use a JazzMutant Lemur in midi mode via control watcher to control the Kaleidoscope.

When I move a parameter nothing happen until more than on minute and after that the information appear in the monitor status and the change take effect with freeze.

My patch was create on Isadora 1, and work great on it.

What can I do.

Thnaks

mark

@thyeks,

Are you changing the picture input via MIDI? It would be helpful if you could post your patch or an example so we can examine it. Or file a bug report and send your patch to us privately.

To submit a bug report, go to http://troikatronix.com/support/isadora/ and choose "Bug Report" from the topic menu/dropdown.

Best Wishes,

Mark