[Vorbis-dev] Qyery on bark equation in floor0 code

[Monty]

On Mon, Dec 20, 2004 at 11:26:32AM +1100, Michael Smith wrote:
> On Friday 17 December 2004 15:25, nagaraja.sreerama at wipro.com wrote:
> > Hi All,
> > I need some clarifications regarding the mismatch I found in the code
> > and the specification.
> >
> > (a) In the specification, the bark(x) equation is given as:
> >
> > bark(x) = 13.1 atan(.00074x) + 2.24 atan(.0000000158(x^2)) + .0001x
> >
> > whereas in the code it is given as:
> >
> > #define toBARK(n)
> > (13.1f*atan(.00074f*(n))+2.24f*atan((n)*(n)*1.85e-8f)+1e-4f*(n))
> >
> > Which one of these is the proper one ?
> 
> The one from the code is what is in wide use - it also matches more closely 
> with the commonly quoted references for this scale. 
> 
> I'm pretty sure this is a typo in the spec - I'll wait to see if Monty replies 
> before changing it, though. Thanks for picking up on it!

Sorry, was on Xmas holiday.

The spec has the digits transposed.  The code is correct.

Monty