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Delayed reaction on audio

Posted: Sat Jun 20, 2015 9:47 am
by Reigel
Hi,
I have a project running with live audio inputs. Problem is that the visual response to ingoing audio is delayed too much, some 0.5 seconds at least.
I use RME FireFace with very small buffers. All in all there should not be more than 20 mS of delay be introduced by that. So the main delay must be generated by Magic.
Is that known? Do I wrong something? It is a quite fast machine (i7) with 16 G of RAM and a midsized NVidia card.
I have 4 videos running as a source which shall be tweaked by the sound. Videos are of different size but alltogether less than one HD size.

Best
Reinhard

Re: Delayed reaction on audio

Posted: Sat Jun 20, 2015 2:35 pm
by Magic
Hmm, .5 seconds is quite a large delay, but I don't think Magic would be causing something like that, especially with an RME audio device if the buffers are small as you described.

Have you looked at the Optimizing section in the User's Guide? There are a few things that could cause a delay, such as your display device itself (a phenomenon known as display lag).

I guess really the main question is, have you noticed a visual response delay in other programs, or does it just seem to be happening in Magic?

Also, have you tried creating a new project with just a Waveform module? Do you notice the delay there, or is it only with the Video modules?

Re: Delayed reaction on audio

Posted: Sun Jun 21, 2015 12:06 pm
by Reigel
Hi, and thanks for response.

first: It is also delayed when I use a waveform-modul.
Then: The dispaly device is a Panasonic PT AT 5000. This has a small delay I know. But I did not think it was so big. When I use it with a bluRay-player no extra delay for audio is necessary normally. Anyway, I will try to find a way to measure that somehow. Maybe this is the point.
Can You give some figure on how much display lag is common for HD-beamers?

Best
Reinhard

Re: Delayed reaction on audio

Posted: Mon Jun 22, 2015 12:11 am
by Magic
Generally, display lag isn't higher than 100ms. But 100ms is pretty bad. 500ms (.5 sec) is unusable, I'd say. Under 16ms is ideal (one frame at 60Hz: 1000/60 = 16.6).

There is some useful information in this Wikipedia article: https://en.wikipedia.org/wiki/Display_lag

This is generally considered the definitive site for display lag statistics: http://www.displaylag.com/

For your case, can you try connecting a different monitor to see if the problem gets any better?

Also, are you running on OS X or Windows? If it's Windows, make sure you are using the ASIO driver for your RME device, and verify that the buffer size is small: https://magicmusicvisuals.com/downloads ... BufferSize

Right now I can't think of any other potential sources of the problem, but I will let you know if I do :).