[Linphone-developers] Problem with oRTP

[Daniel Kriesten]

Hi,

I don't know if I am right on the developers list may be it is a users
request?

I am writing a small SIP / RTP client using eXosip and oRTP. The sip
part works fine, but I am having trouble receiving (or may be sending?)
data oder oRTP.

One problem is, that (accordint to oRTP-debug output) the timestamp is
increased unexpected. My application is always receiving 160 bytes, so
in the logs it shoul look like:
oRTP-message:rtp_getq(): Timestamp 0 wanted.
oRTP-message:rtp_getq(): Timestamp 160 wanted.
oRTP-message:rtp_getq(): Timestamp 320 wanted.
and so on?
But quite often some of the reqests went lost(?) so it looks like:
Enqueuing 0,160,
0 wanted -> returning 0
Enqueuing 320,
160 wanted -> returning 160
Enqueuing 480,640
640 wanted -> returning 640...

An other problem is that the queue runs empty and thus the timestamps
become asynchronous. In the logs it looks like:
oRTP-message:rtp_getq(): Timestamp 7040 wanted.
oRTP-message:No mp for timestamp queried
oRTP-message:rtp_session_recvm_with_ts: packet_time=840, time=820
oRTP-message:scheduler: processing session=0x804f498.
oRTP-message:scheduler: processing session=0x804f498.
oRTP-message: hwrcv_diff_ts=320, rcv_diff_ts=320
oRTP-message:rtp_parse: silently discarding very old packet (ts=7040)
oRTP-message: hwrcv_diff_ts=320, rcv_diff_ts=320

Some times only some (up to 3) samples are lost, but sometimes the
session never becomes synchronous again.

One thing I recognized is, that the filling and emptying of the queue
happens in a kind of bursts. So there are 30 or 50 packets enqueued and
than the application reads as much as enqueued or more. This again leads
to packetloss...

The problems not only occures with my sample programs, but also with the
sender / receiver samples from oRTP. It seems to work better if the
sender is slightly slower than the receiver.


I compiled oRTP from linphone-cvs using --disable-ipv6
--enable-debug=yes --enable-glib --enable-glibtest --disable-gtk-doc

glib-2.0.1 and gcc 2.95.4
glib-2.4.8 and gcc 3.3.5
(on two diffrent pcs)


May be someone can give me a hint on how to go on debugging my
application? I can also send some more extracts from ortp-logfiles.

Thanks in advance!

Best regards
        Daniel

--
Daniel Kriesten
Homepage & PGP: http://www-user.tu-chemnitz.de/~krid