dauto2 [window_size] < input.doubles > output.doublesDAUTO2(1)
NAME
dauto2 - compute the center-clipped autocorrelation function of doubles
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SYNOPSIS
DESCRIPTION
dauto2 reads a stream of double-precision floating-point numbers from standard input, computes an estimate of the autocorrelation function using center-clipping, and writes the resulting double-precision values to standard output.
The data is processed one window at a time, window_size samples per window (default 512); a short final window is zero-padded. Before the autocorrelation lags are computed, dauto2 applies center-clipping to suppress formants for pitch extraction: the clipping threshold is set to 60% of the smaller of the peak magnitudes found in the first half and the last third of the window, and each sample is quantized to -1, 0, or +1.
Like dauto(1), this filter operates on raw 64-bit host-order doubles such as those produced by other tools in the BRL-CAD signal-processing suite.
OPTIONS
- window_size
-
Number of samples per processing window (default 512). Given as a single optional positional argument; dauto2 takes no flag options.
EXAMPLES
Example 1. Estimate pitch periodicity of a speech signal
dauto2 1024 < voice.doubles > voice.autocor.doublesComputes the center-clipped autocorrelation of voice.doubles using a 1024-sample window. The center-clipping suppresses the strong formant structure of voiced speech, so peaks in the output correspond to the pitch period, which can then be plotted or tracked downstream.
SEE ALSO
brlcad(1), dauto(1), damdf(1)
AUTHOR
BRL-CAD Team
COPYRIGHT
This software is Copyright (c) 1989-2026 by the United States Government as represented by U.S. Army Research Laboratory.
BUG REPORTS
Reports of bugs or problems should be submitted via electronic mail to devs@brlcad.org