latency

Getting Stuff Done How do I .... ?
#1

Hi,

got a problem with latency compensation. As soon as I switch the periods/buffer option in jack to a value higher than 2 wrong latency is reported to ardour which causes wrong compensation. Example:

Frames/Period -> 4096
Periods/Buffer -> 2
Jack Latency -> 186ms
Ardour Latency -> 93ms

but
Frames/Period -> 4096
Periods/Buffer -> 4
Jack Latency -> 372ms
Ardour Latency -> 93ms (!) as before, but should be 372 div 2

Is this problem related to Jack or Ardour?

regards,
sebastian

#2

The latency reported by Ardour is not roundtrip latency, but output latency. This is a problem with the word “latency”, which has several possible definitions (input, output, through, just to get started). JACK control apps tend to show through latency; Ardour only shows output latency.

#3

As a follow up, you should probably talk more about why you think latency compensation is messed up, and why you think the error is related to the JACK period size.

1 Like
#4

when I set JACK period size to 4 I get an audible latency with my usb interface between all the recorded tracks. Setting it to 2 and all works fine.

Setting Periods/Buffer to 4 JACK reports a round trip latency of 372ms while ardour still reports a single latency of 93ms instead of 186ms. So I think it corrects only half of the correct value. Which would fit to the audible latency I heard and could see on the waveform

#5

forgot to mention. while recording I use direct monitoring via the usb interface.

#6

This has to be some of the dirtiest form of spam I’ve seen in a long time and it’s been almost non stop for weeks now. If anybody moderates these boards, can we block them by IP? By subnet if we have to?