[Linphone-developers] silent packets / timestamp jump in the future detected

[Matthew H]

Hi,

I am using a simple tool called TRX to transmit audio over a network.
It wraps opus in RTP and sends it to the receiver using the ORTP
library. There is no SDP or signalling involved.

In an attempt to reduce bandwidth I have enabled DTX in the opus
encoder. With DTX enabled, a packet is only sent every 400ms during
periods of silence.

Fundamentally it's working well, but the receiver side is repeatedly
logging "rtp_parse: timestamp jump in the future detected". Looking at
the code this occurs here -
https://github.com/BelledonneCommunications/ortp/blob/b03ae4169dc11adbc789f8c1943c44da2de3068c/src/rtpparse.c#L349

So it seems like this is triggered when the timestamp of the current
packet is greater than the previous received timestamp + 256 ( jitter
buffer x 16 )

Short of increasing the jitter buffer or patching ortp, is there a
more sensible way of handling this to avoid the errors?

Thanks
Matthew