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Delayed reaction on audio

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Reigel
Posts: 81
Joined: Sun Mar 15, 2015 9:56 am

Delayed reaction on audio

Post 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.

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Reinhard
Magic
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Posts: 3440
Joined: Wed Apr 09, 2014 9:28 pm

Re: Delayed reaction on audio

Post 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?
Reigel
Posts: 81
Joined: Sun Mar 15, 2015 9:56 am

Re: Delayed reaction on audio

Post 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?

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Reinhard
Magic
Site Admin
Posts: 3440
Joined: Wed Apr 09, 2014 9:28 pm

Re: Delayed reaction on audio

Post 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 :).
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