Speex dev - Aug 2004 - narrowband embedded in wideband

Is there any way to access only the narrowband portion of a wideband
stream?

I'd like to be able to encode the audio only once, but allow members
in a conference to have some rough selection of bandwidth, and allow
them to move to a lower-bitrate stream if there is a need to do so.

Thanks,
Matthias

-- 
Matthias Granberry
matthias@utdallas.edu
(469) 371-0596
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> Is there any way to access only the narrowband portion of a wideband
> stream?
Try encoding a stream in UWB or WB mode using speexenc. speexdec has command
line options you can use to force it to NB decoding only. So yes, it is
possible.
And the implementation in speexdec.c should show you how.

Christian

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It looks like I'll need to go further into the guts of speex to do
this.  I do, however, see some lines in nb_celp.c/nb_decode() that
look interesting.  I guess I'll play with it.  I doubt that it will be
terribly clean, though.

 Jean-Marc: Take a look at line 1195 in nb_celp.c (CVS).  It reads
 "speex_warning ("More than to wideband layers found: corrupted
 stream?");" when it should be "More than two wideband
layers..."

"Christian.Buchner" <Christian.Buchner1@epost.de> writes:
>> Is there any way to access only the narrowband portion of a wideband
>> stream?
>
> Try encoding a stream in UWB or WB mode using speexenc. speexdec has
> command line options you can use to force it to NB decoding only. So
> yes, it is possible.  And the implementation in speexdec.c should
> show you how.
>
> Christian
>
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-- 
Matthias Granberry
matthias@utdallas.edu
(469) 371-0596
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