[mus422] Alternate quantization algorithm

[Craig Sapp]

Hi Music 422 Class,

Here is the first slide with the altered quantization algorithm from
Friday's class.  I didn't copy down all of the second slide for the
complimentary dequantizing algorithm, but that should be posted
soon...

Using LaTeX syntax below, where text between $$ are equations/variables.

===================================================================

To convert from a number into a scale/mantissa floating point code
with $R_s$ scale (exponent) bits and $R_m$ mantissa bits.  $s$
represents the sign bit (0 = positive, 1 = negative) which is the most
significant bit of the mantissa.

I. Quantize the number as an $R_u$-bit uniform quantization code where
$R_u = 2^{R_s}-1+R{m}$.

II. Count the number of leading zeros in the resulting uniform
quantization code, excluding the sign bit, $s$.  If the number of
leading zeros is less than $2^{R_s}-1$, then set the scale equal to
the number of leading zeros; otherwise, set the scale equal to
$2^{R_s}-1$.

III.  If the scale is equal to $2^{R_s}-1$, then set the first
mantissa bit equal to $s$, and set the remaining $R_m-1$ bits equal to
the bits following the $2^{R_s}-1$ leading zeros in |code|; otherwise,
set the first mantissa bit equal to $s$, and set the remaining
${R_m}-1$ bits equal to the bits following the leading zeros, {\emph
omitting the leading one}.

======================================================================

-=+Craig