SV: [speex-dev] Some simple questions

Jonas Tärnström njt at home.se
Thu Sep 25 18:33:33 PDT 2003



Maybe this is plain stupid or off topic.
Could an atleast working fixed-point implementation of Speex be made by
using a C++ "faked float" class with overloaded operators?

Don't know if this is a common way to solve stuff like this, but my
guess is that it would work.

//Best Regards, Jonas Tärnström.

<p>> > So just how much work are we talking about, here, to convert to
fixed-
> point?
> > Seems like with some clever type substitution and a few inlines here
and
> > there it might maybe not be so horrible?  But, then, I haven't
looked
> inside
> > of Speex yet, and don't have a sense of scale...
> 
> That's not as simple. With floating point, you can take any two
numbers,
> multiply them together and not risk an overflow (not quite but it's
true
> in the context of Speex). With integers, that's not the case. You have
> to know the range for all the inputs and then (usually) do some
shifting
> according to that.
> 
> My estimation is that it would probably require in the order of 100
> hours for someone (with prior experience) to convert Speex to
> fixed-point. Anyone is up to the task?
> 
> 	Jean-Marc
> 
> --
> Jean-Marc Valin, M.Sc.A., ing. jr.
> LABORIUS (http://www.gel.usherb.ca/laborius)
> Université de Sherbrooke, Québec, Canada

<p>--- >8 ----
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