[Speex-dev] pre-processing for audio quality

[Jean-Marc Valin]

I've never tried Skype, but I think it can be made to use wideband (16
kHz) encoding, which would explain why you say it sounds clearer. You
can do the same with Speex too. As for the preprocessor, what it could
give you is to remove the background noise and/or adjust the gain.

	Jean-Marc

Le jeudi 14 avril 2005 à 23:08 -0700, KC Lee a écrit :
> We are using Speex as our major codec for voice application. We like 
> the Speex solution so far. Currently,
> We have tried to compare voice quality between different 
> public available VOIP solutions such as Skype and others.
> We notice Skype use higher CPU for signal processing. Is it
> because of this extra work the audio quality sounds clear?
> (Sometimes, it sounds like the audio signal is not real. 
> It sounds like Dolby-effect has been added.)
>  
> We are wondering whether we need to preprocess the audio 
> signal before it gets into Speex codec. 
>  
>     Any comment is appreciated!! Thanks in advance.
>  
> kc
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-- 
Jean-Marc Valin <Jean-Marc.Valin at USherbrooke.ca>
Université de Sherbrooke