Troubleshooting Sound Problems - pjsip.org

Troubleshooting problems in the audio quality is one of the most difficult task to do with PJMEDIA, because mostly it is system specific. This page will try to provide a step-by-step troubleshooting guide to assist solving such problems.

Understanding Media Flow

Please see Understanding Media Flow for detailed explanation.

Types of Problems

There are tooo many audio quality problems than those mentioned below, but anyway lets try to enumerate them and present with some kind of troubleshooting guide:

1. No audio is heard on local speaker during the call
2. No Audio is Heard by Remote Party
3. Loud Static Noise
4. Brief Drop-Outs in Audio
5. I'm sending tone in .WAV file from pjsua but got "stutters" on the remote side
6. High jitter value observed by remote party

All Checklists

1. Check that the correct device is being used.
2. Check that speaker is functioning properly by Looping-back Microphone to Speaker device.
3. You can also check by Playing a WAV File to Speaker.
4. Check that Incoming RTP Packets are Indeed Received by Local Host
5. Check that the Call is Connected to the Sound Device in the Conference Bridge.
6. Check that CPU Utilization is not Too High
7. Checking the Echo Cancellation Effectiveness?

One mailing list member reported this problem in this thread:

​http://www.pjsip.org/pipermail/pjsip/2006-November/001111.html

Quoting his email:

Does anyone else experience brief dropouts in audio? I can easily recreate this by playing a wave file to a channel that sends it to a local SIP server that just echos the result back. It's almost impossible to go more than a few seconds without extensive glitching and pops as the sound cuts out only to come back.

The solution that worked for him is to run the application in Release mode. Quoting his email again:

Seems one shouldn't use pjsip compiled in debug mode. (-g.) Going back to optimized cleared things up.

One mailing list member tried to stream a .WAV file containing tone to X-Lite and SJPhone and observed audio "stutters" in the receiving side. But this didn't happen when the receiving side is another pjsua.

Solution: don't send tone file to these user agents, as it's suspected that they try to do something with the in-band tone. Use .WAV file containing usual speech and it should be okay.

High jitter value observed by remote party