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<DIV><FONT face=Arial size=2><SPAN class=271430704-17122004>Hi
All,</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=271430704-17122004>I need some
clarifications regarding the mismatch I found in the code and the
specification.</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=271430704-17122004></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=271430704-17122004>(a) In the
specification, the bark(x) equation is given as:</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=271430704-17122004><FONT face=Arial
size=2></FONT></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=271430704-17122004><FONT face=Arial
size=2>bark(x) = 13.1 atan(.00074x) + 2.24 atan(.0000000158<SPAN
class=397420504-17122004>(</SPAN>x<SPAN class=397420504-17122004>^</SPAN>2)<SPAN
class=397420504-17122004>)</SPAN> + .0001x</FONT></DIV></SPAN></FONT>
<DIV><FONT face=Arial size=2><SPAN
class=271430704-17122004></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=271430704-17122004>whereas in the code
it is given as:</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=271430704-17122004></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=271430704-17122004>#define
toBARK(n)
(13.1f*atan(.00074f*(n))+2.24f*atan((n)*(n)*1.85e-8f)+1e-4f*(n))<BR></SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=271430704-17122004>Which one of these
is the proper one ?</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=271430704-17122004></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=271430704-17122004>(b) Also, we are
planning to implement a fixed point code for the Vorbis decoder. And as usual
the obvious criteria is the compliance and how accurately this fixed point code
should generate the output that matches mathematically the floating code
implementation. Specifically I feel that the tremor code implements the linear
approximation depending on some specific baud scales (0, 100, 200,
301, 405, 516 etc...). I have a feeling that this leads to some inaccuracy
in the results compared to the floating point code. Is this acceptable ? What is
the basis for acceptance say the algorithm should mathematically match the
specification ?</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=271430704-17122004></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=271430704-17122004>Can somebody throw
light on this ?</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=271430704-17122004></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=271430704-17122004>Best
regards,</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=271430704-17122004>nags..</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=271430704-17122004> </DIV></SPAN></FONT></BODY></HTML>
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