Re: [LAD] Strange inconsistency in jack frame time

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To: Fons Adriaensen <fons@...>
Cc: Linux Audio Developers <linux-audio-dev@...>
Date: Sunday, June 22, 2014 - 10:16 pm

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On Sun, Jun 22, 2014 at 5:38 PM, Fons Adriaensen
wrote:

>

I don't think that anything in the API documentation suggests that it is.

xruns, whether caused by clients or kernel scheduling, essentially reset
the clock. nothing in jack1 (and i believe nothing in jack2) attempts to
maintain clock consistency (monotonicity or linearity) across xruns.

of course, there is a legitimate argument that this would be useful, but it
would require (as far as i can tell) a bunch of assumptions that while
often correct, are not really solid. most of them relate to the ability to
continue using a DLL that links a system clock and the audio clock across a
restart of the audio clock (since the system clock is the only thing that
could keep running as far as JACK is concerned).

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On Sun, Jun 22, 2014 at 5:38 PM, Fons Adriaensen =
<fons@linuxaudi=
o.org
> wrote:

So it seems that the frame time is not a reliable method to
determine how many frames have been lost.I don't think that anything in the API documentation suggests that i=
t is.xruns, whether caused by clients or kernel scheduli=
ng, essentially reset the clock. nothing in jack1 (and i believe nothing in=
jack2) attempts to maintain clock consistency (monotonicity or linearity) =
across xruns.
of course, there is a legitimate argument that th=
is would be useful, but it would require (as far as i can tell) a bunch of =
assumptions that while often correct, are not really solid. most of them re=
late to the ability to continue using a DLL that links a system clock and t=
he audio clock across a restart of the audio clock (since the system clock =
is the only thing that could keep running as far as JACK is concerned).

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Messages in current thread:
[LAD] Strange inconsistency in jack frame time, Fons Adriaensen, (Sun Jun 22, 9:39 pm)
Re: [LAD] Strange inconsistency in jack frame time, Paul Davis, (Sun Jun 22, 10:16 pm)
Re: [LAD] Strange inconsistency in jack frame time, Fons Adriaensen, (Sun Jun 22, 11:51 pm)
Re: [LAD] Strange inconsistency in jack frame time, Fons Adriaensen, (Sun Jun 22, 9:42 pm)