NAME
pppeak - pitch tracking for EGG data
SYNOPSIS
pppeak [-a val] [-c ch] [-i] [-l wsize] [-o offset] [-t thresh] [-v] [-w] [-z coef] filename1[.wav] filename2[.pps]
DESCRIPTION
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.
OPTIONS
-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)
SEE ALSO
AUTHOR
S.R. Hoskins