Perfectly fine incoming RTP stream, but audio dropout with CSipSimple

> What steps will reproduce the problem?

1. Make a call with Ethernet connection (e.g with USB-Ethernet adapter, or use 
a cubieboard, banana pi or olimex board with built-in Ethernet port) and a 
server (asterisk with "Milliwatt" application as audio test source) in the same 
network to get perfect RTP

2. capture the incoming RTP with tcpdump straight from eth0 on the android 
device. And in wireshark you see, perfect fine RTP with min. jitter and no 
paket loss.

3. Repeat listen to the audio from CSipSimple. Time after time you hear audio 
dropout, but RTP from capture is perfect.

> What is the expected output? What do you see instead?

No audio dropout, when incoming RTP is fine.

> What version of the product are you using? On what device / operating
> system?

Test with variety of devices and android version. Always same issue.

> Please provide any additional information below.

Test with zoiper in the same setup -> no audio dropout.

My assumption, there must be an issue where pjsip/csip deliver the audio to 
OpenSL-ES not consistent enough? Try to debug OpenSL-ES, to see if the audio 
dropout correlate with any buffer underrun or the like in this area?

Original issue reported on code.google.com by k.vr...@gmail.com on 5 Feb 2015 at 12:37

juniorlm87 / csipsimple

Perfectly fine incoming RTP stream, but audio dropout with CSipSimple #2879