Packetization - not using ptime parameter correctly

[AndrejHafner]

Hello,
we found out that the parameter ptime (packetization time) which is 20 by default isn't being correctly used by the library. The reverse times on wireshark are correct (delta ms = 20), but the forward (outgoing packets) have different deltas, but they form a pattern. Here's a picture from RTP stream analysis:

Both graphs should be at around ~20ms, but the forward graph isn't.

Here's the data:

We would like that both times would be same as ptime parameter.

Thank you in advance!

EDIT:
I have found out that the delay happens when capturing the sound from DirectSound API. The delay occurs at line 84 in tdav_producer_dsound.c .

dwEvent=WaitForMultipleObjects(TDAV_DSOUND_PRODUCER_NOTIF_POS_COUNT,dsound->notifEvents,FALSE,INFINITE);

On average the delay is same as ptime(20ms), but it is actually something like: 30-30-0-30-30-0 (ms) and so on instead of 20-20-20-20-20 (ms).