[Speex-dev] Encoding mode

[Jean-Marc Valin]

Le mardi 14 mars 2006 à 20:32 +0100, Michel de Boer a écrit :
> Hello,
> 
> In the internet draft describing the SDP parameters for speex
> I find this:
> 
> 	 mode:  Speex encoding mode. Can be {1,2,3,4,5,6,any}
>                  defaults to 3 in narrowband, 6 in wide and ultra-wide.
> 
> In the documentation I can only find the following request:
> 
> 	SPEEX_SET_MODE
> 
> There is no description though what this request does.
> 
> I think the mode somehow maps to the bitrate, but I cannot
> find a table that tells me which mode maps to which bitrate
> for nb, wb and uwb codecs.

Here's the info for narrowband:
http://www.speex.org/manual2/node9.html#SECTION00094000000000000000
For wideband and uwb, the modes are the same as the quality settings
(sorry, don't have a table).

> And what does it mean when mode=any?

Means: "I will take any mode you like".

> Can someone explain me what the mode indicates?

mode == bit-rate.

Note that the draft is still not finished. I'm still looking for someone
who knows this stuff (SIP/SDP/RTP/...) to help me finish it.

	Jean-Marc