normalisation of audio signal and reverting to original matlab -
i doing project in audio stenography. need embed text in audio signal(.wav file) . converted audio signal ranging -1 1(double) -32767 +32767(int16) cold embed data in lsb of coefficients. problem don't know how values int16 respective double equivalents.
i have used following code normalization:
[y, fs, nbits,opts]=wavread('one.wav'); y2=y-(min(y)); y2=y2/max(y2); y2=y2* (2^16 - 1) - 2^15; y2b=int16(y2);
can guide me reverse process of this?
looks need save (and store) ymin = min(y)
, y2max = max(y2)
reversal. double version ofthe int16 , perform reversal procedure needed:
y3 = double(y2b); y3 = (y3 + 2^15) / (2^16 - 1); y3 = y3 * y2max; y3 = y3 + ymin;
then store y3 output file needed.
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