[Speex-dev] RE: Speex-dev Digest, Vol 27, Issue 18

Jean-Marc Valin jean-marc.valin at usherbrooke.ca
Thu Aug 17 22:40:53 PDT 2006

> I cover some VoIP issues.  I was at VoIP developer conference and asked an
> embedded manufacturer (we're talking Wi-Fi phones) about supporting Speex in
> their embedded products.  He said that Speex was good but it's too many
> things to too many people and that he couldn't supported it in his embedded
> products for the following reasons.

Speex has lots of features but I'm not forcing anyone to use them all.

> *	Code size must be extremely small

Please define "extremely small", that's very relative.

> *	Data working set must also be extremely small

Please define "data working set" and "extremely small".

> *	Use very few MHz of a DSP

Please "very few" :-)

> *	Needs packet loss concealment (I believe Speex has this)

Yes, Speex has that.

> His recommendation was that because packet overhead alone was in the 24 kbps
> range, there is nothing wrong with having a 16 KHz wideband stream that uses
> 24 kbps so long as it meets the above embedded criteria.  He said that the
> VBR support and ultra low bandwidth capability wasn't really useful.

Wideband Speex is actually in this range of bit-rate. I usually
recommend between 20 and 28 kbps). And I agree that VBR and ultra low
bandwidth are useless for that application.

> What we need is something that would meet the lowest common denominator in
> hardware yet deliver a wideband stream in less than 24 kbps for the payload.
> Can someone comment on this?

You've pretty much described the main application I had in mind when
doing Speex. I really don't see what the problem is.


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