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              Simple program to illustrate Intel(R) Integrated Performance Primitives
              (Intel(R) IPP) function use (full, partial and decimated autocorrelations)
              for pitch determination algoritm.

This example shows how Intel(R) IPP functions could be used to estimate pitch for voiced
intervals of input speech. The example follows the pitch determination algorithm described
in Y Medan, E Yair, D Chazan. Super Resolution Pitch Determination of Speech Signals.
IEEE Transactions on Signal Processing, vol.39, no.1, January 1994.


      pitchdemo.cpp

The main program contains winapi finction. The example uses two way of determine pitch
1. Open the 16KHz wave file
2. Record speech signal from the mic. Last 20 seconds of speech are only recorded.

Output screen:
X: Output pitch start from first voice sample and have output scale - 1 pixel on 4 samples
Y: Pitch in interval from MIN pitch to MAX pitch.


      sound.cpp

The sounds record function.

      pitchdemo.cpp

short *DoFilter(const short *pInputBuffer, int nInLength)
 4 4 5 filter averaging filters

void DetectSilence(short *pInBuffer,unsigned char *pSilent,int VecSize)
 detect and erase silence from input signal

int DetectPitch(short *pInBuffer,unsigned char *pSilent,int nInLength,_PitchStruct *pPitch)
 determinate pitch from input signal and fill _PitchStruct struct.
 return number pitch.

Following thresholds have been taken from the article.
MIN_PITCH     100.0
MAX_PITCH     250.0

TMIN          0.80f
TMAX_RATIO    0.87f
THIGH         0.85f
TDH           0.77f