[Speex-dev] different output for opt/non-opt on win32 platform

Jean-Marc Valin Jean-Marc.Valin at USherbrooke.ca
Tue Jan 4 22:48:24 PST 2005

Le mercredi 05 janvier 2005 à 13:37 +0800, tunkeat a écrit :
> thanks Jean for the codec. 

My first name's Jean-Marc BTW :-)

> I am new to speech coding. Am interested to implement 
> speex on a TI dsp, say C54. 

I think I've heard someone was working on that before...

> just downloaded speex v 1.1.6.
>  when I removed optimisation flags for win32 in libspeex.dsp, 
> I get a slightly different output for decoding using speexdec.exe 
> (debug version). no prob for speexenc.exe except for some 
> differences in the ogg header. 

What difference in the ogg header? It's quite normal that compiler
options will (slightly) change the result. The reason is that the
rounding depends on when the compiler loads/stores the float values. 

> i have the understanding each speex frame is self-contained,
> i.e., the decoder could decode each frame independently. is that
> right?

No. Like any other CELP codec, Speex has a memory. The only non-PCM
speech codec I know that has independent frames is iLBC and it's
suboptimal for most uses because of that.


Jean-Marc Valin <Jean-Marc.Valin at USherbrooke.ca>
Université de Sherbrooke

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