UUID_RECORD cause to different duration

Hi all,

Freeswitch initiates a phone call. One end is the customer service using the webrtc web page, and the other end is the real phone customer. uuid_record is used to record the two channels respectively, but why are the durations of the two wav recording files different?

The recording instructions are as follows:
uuid_setvar record_sample_rate 8000
uuid_setvar RECORD_STEREO true
uuid_record start /home/admin/recording/xx/xx/xxx.wav

The ESL client receives the start recording event of the two channels at the same time, and the time of the end recording event is also the same.

The recording time on the phone is normal, and the recording on the web will be 2-3 seconds longer per minute on average (a 5-minute call on the web customer service channel will be more than 10 seconds longer), but the recording content starts and ends the same. Insert extra silence segment if it does not exist

How long was one call not ringing? because recording won’t actually start until media is flowing.


Hi Brian,
It is not related to ring time.
The content (conservation) of 2 recording file are same, The wave-form are congruent. but recording file of web leg is stretched.

@BrianWest-SW Any Idea on what is cause of issue, can we confirm it is freeswitch bug?

Its not really an issue, is it?

It is a issue,
We record call per leg for combine all for full call later. example:

  • List item
  • A call B, A & B in call (conversation AB)
  • B attended transfer A to C
  • B and C in call (conversation BC)
  • B complete transfer
  • A and C in call (conversation AC)

as the administrator, we want a call with full conversation, but different duration make a merging them be impossible.

even it is not issue for us, call duration should be correct in anyway.

Its going to be timing between the channels and remote media, there isn’t much we can do about that, the way you’re approaching it is just odd to me, you should record in stereo on one side or the other.


Hi Brian,
Thanks for your answer, can you clarify more on “Its going to be timing between the channels and remote media”?

If I understand correctly, you mean the timing of freeswitch channel and timing in remote media is not same … should rtp-rewrite-timestamps fix the issue?