[Speex-dev] Single frame or multiple frame inside rtp packet?

Jean-Marc Valin jean-marc.valin at usherbrooke.ca
Thu Sep 7 02:47:36 PDT 2006

> I have created a voip application using speex. My
> internet line is 64Kbps. 
> I`m using narrow band mode, 8000 bitrate, 20ms of
> 8000Khz sampling rate, no buffering, no preprocessing,
> just set bitrate and go.
> When i send single frame inside rtp the sound was not
> good, choppy and noisy. But when i pack around 8 frame
> inside rtp packet, the sound was better.

Most likely reason is that it's not related to bandwidth, but that you
probably screwed up either the network or the audio buffering.

> My question are:
> 1. Which one is best practice?

It's usually best to use one (or at most two) frames per packet because
of latency.

> 2. How to correctly measure bandwidth usage of speex
> packet?

The overall bandwidth using RTP is:
speex_bitrate + 16kbps/frames_per_packet


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