On Sun, Jun 22, 2014 at 5:38 PM, Fons Adriaensen <fons(a)linuxaudio.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 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).