[Live-devel] High peaks in processing times

[Julian Lamberty]

Hi!

I've developed a class to transcode video streams. I measure the time 
between "doGetNextFrame()" and "afterGetting(this)" with the 
gettimeofday() function. The results show that it takes in average 40ms 
to complete one frame (according to the frame rate of 25Hz). But 
irregularily one frame takes more than 120ms which seems to be 
"compensated" in the next frames. The transcoding time is far below 40ms 
for each frame. Sample:

...
39.88ms
39.79ms
39.84ms
40.23ms
40.00ms
39.11ms
124.25ms (peak)
17.79ms (shorter periods)
17.87ms
17.54ms
20.20ms
38.52ms (back to normal)
39.76ms
...

What could this come from? I'm using Fedora Linux, is there maybe a 
kernel/user switch or anything similar involved?

Thanks
Julin