Speex dev - Nov 2005 - RTP profile draft!

Hi Jean-Marc and list,

I'm trying to negotiate speex with SIP/SDP and get some trouble
understanding the "mode" parameter:

mode:  Speex encoding mode.  Can be {1,2,3,4,5,6,any} defaults to
       3 in narrowband, 6 in wide and ultra-wide.

Is mode equivalent to the "quality" parameter of speex?

In this case, I don't understand why mode is not from 1 to 10...

Just for additionnal note, it seems the word "mode" is also
used for talking about the *-band things:
   "Each frame contains both "mode" (narrowband, wideband or
    ultra-wideband)"

that's an additionnal confusion that may need a fix...

Thanks for all,
Aymeric

Hi Aymeric,
> mode:  Speex encoding mode.  Can be {1,2,3,4,5,6,any} defaults to
>        3 in narrowband, 6 in wide and ultra-wide.
> 
> Is mode equivalent to the "quality" parameter of speex?
No. The quality parameters all map to a certain mode, but they are not
the same. See http://www.speex.org/manual2/node9.html for a list of the
modes.
> Just for additionnal note, it seems the word "mode" is also
> used for talking about the *-band things:
>    "Each frame contains both "mode" (narrowband, wideband or
>     ultra-wideband)"
> 
> that's an additionnal confusion that may need a fix...
I think the draft only uses "mode" for bitrate and uses
"bandwidth" for
narrowband vs wideband. I guess it may be confusing that libspeex uses
mode for the sampling rate and sub-mode for the bitrate. Can you suggest
a better term to use in the draft?

	Jean-Marc