pppeak - pitch tracking for EGG data


pppeak [-a val] [-c ch] [-i] [-l wsize] [-o offset] [-t thresh] [-v] [-w] [-z coef] filename1[.wav] filename2[.pps]


pppeak() analyzes the data in wavefile filename1 and writes a pitch period file into filename2. The pitch period algorithm is a peak detection method; the first peak above the specified threshold after a positive-going zero crossing is identified as the beginning of a pitch period, and a pitch mark will be written to the output file at this location. An offset may be added to this location. Before a peak is detected, the wavefile data is filtered to remove DC and noise as follows:

Y(t) = x(t) - x(t-1) + Z * Y(t-1)
where Z is a coefficient (default 1.0)
specified as an option by -z

The user may specify the threshold and also change the direction of the peak detection (search for negative-going peaks).

Note - this program was written to provide pitch tracking for EGG data only. The peak detection algorithm will work very poorly on speech or other periodic waveforms.


-a val sets the automatic threshold level, used when an absolute threshold (see -t) is not specified. val must be a fraction between 0.0 and 1.0; the value sets the threshold, with respect to the maximum peak in the file. The default value is 0.15 (15% of maximum).

-c ch selects the active channel. The default is channel 1 for a multichannel file.

-i inverts the input data, so the pitch mark is aligned with a negative peak. The default is a positive peak.

-l wsize specifies the size of the window in ms. default is 10 ms.

-o offset adds an offset in number of samples to the pitch mark location

-t thresh selects the threshold level for detecting a peak; the value may be 0 to 32767. If not specified, the program will select a threshold based on the maximum peak value and the -a parameter (default is 15% of maximum value)
-w specifies a high pass filtering window applied to the data before the detection begins.

-v verbose mode (prints out state of internal parameters)

-z coef coefficient for filter (see above)



S.R. Hoskins