[Speex-dev] Delays estimation in Speex algorithms

Jean-Marc Valin jean-marc.valin at usherbrooke.ca
Mon Jun 29 17:38:20 PDT 2009

Alexander Chemeris a écrit :
> I want to do a careful measure of mic-to-net and net-to-spkr delays
> in sip media engine and to make it really precise I need to know
> delays, introduced by Speex algorithms. In particular, I'm interested
> in delays of:
> 1) encoder in NB, WB and UWB modes,

NB: 25 ms, WB: ~28 ms, UWB: ~30 ms

> 2) decoder (I guess it should be 0?)

5 ms

> 3) resampler. I think it varies depending on input rate to output rate
> ratio. Any generic formula or at least values for specific ratios available?

The higher the quality, the higher the delay

> 4) AEC

0 ms

> 5) preprocessor

1 frame extra delay (i.e. you get back the last frame you sent the last


More information about the Speex-dev mailing list