[Linphone-developers] RTP packets are sent too often

[Daniel Kabs [ML]]

Hello,

I am running linphone on an ARM platform (kernel 2.2). I can call
linphone from my hardware sip telephone. The RTP transfer from the
phone to the ARM system is flawless and with very little jitter (<1ms
according to ethereal). But in the opposite direction ARM platform ->
telephone the packets are sent too fast. That means, linphone does not
send the expected 50 packets per second (160 samples every 20 ms gives
8000 Hz) but 70. So I guess something goes wrong with the internal
timers on my ARM platform.

For this test I replaced the sound card _read() function with a simple
for-loop that fills the read buffer with zeros. So it returns
immediately. Can this influence the frequency with which the packets
are sent? I think no, as the linphone FIFO framework does not rely on
the read function to work as a timer.

Cheers
Daniel Kabs
Germany