Audio drop-outs or “stutters”

The symptom is audio is sounding like it’s skipping some frames.

For a sample audio, play this stutter.wav file [1]. Hear the stutters at 2.5, 3.8, and 8.8 second.

Checklists:

  1. Check by looping back microphone to speaker: check whether the symptom is observable when looping the microphone to the speaker locally.

  2. Check for dangling call in PBX. A dangling call is call that is left active in the PBX because previous (pjsua) application has terminated abruptly.

  3. Check for high network jitter, packet loss, etc.

  4. Check CPU utilization

  5. Try to enlarge PJMEDIA_SOUND_BUFFER_COUNT value by setting it in your config_site.h. Increase it to, say, 16, and see if it fixes the problem. But be aware that enlarging this buffer will increase the audio latency, so find a minimum value where the sound quality doesn’t break.

  6. Check for audio underflows/overflows