


SPECTRAN(1)              USER COMMANDS                SPECTRAN(1)



NAME
     spectran - transform speech waveforms to  spectral  data  by
     fourier transform

SYNOPSIS
     spectran [(-b bandwidth)|(-w window) (-s  stepsize|-o  over-
     lap)] (-n numpixel) (-t offset) (-c) (-p) (-i item) file

DESCRIPTION
     spectran performs a fourier transform on selected windows of
     a  speech  signal  to produce a set of spectral coefficients
     suitable for spectrographic examination.  The windows may be
     of  fixed  length  with a selected overlap or selected step-
     size, or may be positioned by means of a TX item  (in  which
     case  the  unvoiced  periods  are  analysed according to the
     fixed length parameters).  A Hamming window is used for  all
     analyses.   Pre-emphasis  may  be de-selected.  This program
     does not use the array processor.

     Options and their meanings are:

     -I         Identify program and version number.

     -iitem     Select input item number.

     -bbandwidth
                Select analysis bandwidth in Hz. (default 300Hz).
                This  can be used as an alternative to specifying
                window size directly.

     -wwindow   Select  analysis  window  size  in  milliseconds.
                Default is calculated from analysis bandwidth.

     -sstepsize Select analysis window step size in milliseconds.
                Default is calculated from analysis bandwidth.

     -ooverlap  Select analysis window overlap  in  milliseconds.
                Default is calculated from analysis bandwidth.

     -nnumpixel Specify number of energies returned in  spectrum.
                Default  128.   Must be power of 2 between 32 and
                16384.

     -toffset   Select excitation synchronous analysis with  sup-
                plied  offset in micro-seconds between tx markers
                and start point of analysis window.  Negative  is
                earlier, positive later, default is 0.

     -c         Use cepstral filtering to  smooth  spectrum  (cut
                off at 2ms).

     -p         Do not pre-emphasize speech data.



SPAR                    Last change: UCL                        1






SPECTRAN(1)              USER COMMANDS                SPECTRAN(1)



INPUT ITEMS
     1.xx       Any speech waveform.

     3.xx       (Optional) Excitation markers.

OUTPUT ITEMS
     11         Spectral coefficients.

VERSION/AUTHOR
     1.5 - Mark Huckvale (from flfft and others by Lynn  Whitaker
     & David Pearce)

SOURCE
     /ptemp/mark/sfs/ucl/spectran.c









































SPAR                    Last change: UCL                        2



