[Speex-dev] Noisy sound quality with Blackfin in WB-mode

Jean-Marc Valin Jean-Marc.Valin at USherbrooke.ca
Wed Oct 26 03:43:56 PDT 2005

Hi Bernhard,

> Yes, that's right, except one thing: I always use the blackfin 
> +fixedpoint optimized encoder *and* decoder or the fixedpoint-only  
> optimized encoder *and* decoder at one time.  And I do every encoding/ 
> decoding on the Blackfin.

Could you try mixing the encoders and decoders (encode with one version,
decode with the other) to see whether the problem is in the encoder, the
decoder or both.

> Results: The strange sound persists in all WB and UWB combinations,  
> no matter if its the 1.1.11-svn or the 1.1.10 version. No difference  
> between blackfin+fixed and fixed-only in NB modes. The sound is  
> getting even worse when comparing WB to UWB modes. Also sound seems  
> to get worse with raising quality values.

A couple things worth checking: try with WB quality 5 and 8. Do both of
these have a problem (they use a different scheme). Also, with Speex,
it's possible to encode in NB and decode in WB and vice versa. Could you
try that too? With all this information, I should have a good idea of
where the problem is.



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