


HQTX(SFS1)        MISC. REFERENCE MANUAL PAGES         HQTX(SFS1)



NAME
     HQtx - high performance tx from lx

SYNOPSIS
     HQtx (-i item) (-n) file

DESCRIPTION
     HQtx is a program to obtain excitation periods from a laryn-
     gograph signal.  It exploits the characteristic shape of the
     lx waveform  during  voiced  excitation.   It  utilises  two
     derived  functions:  the  sample-by-sample differential, and
     the instantaneous gradient.  Tx points  are  extracted  from
     these  functions  using an automatic threshold determination
     procedure.  This requires that the first 20ms  or  the  last
     20ms  of  the  lx  waveform  be at a background level.  HQtx
     automatically inverts the lx waveform if it is determined to
     be upside-down.  This can be cancelled by the "-n" flag.

     Options and their meanings are:

     -I         Identify program and exit.

     -n         Do not automatically correct for waveform  inver-
                sion.

     -iitem     Select input item number.

INPUT ITEMS
     2.xx       Any excitation item.

OUTPUT ITEMS
     3          High performance tx.

VERSION/AUTHOR
     1.0 - Mark Huckvale.

SEE ALSO
     tx, txgec

BUGS
     Internal filters suitable for 10, 12.8, 16 and  20kHz  only.
     Maximum Fx approximately 500Hz.

SOURCE
     /users/mark/sfs/man/../ucl/HQ.src/HQtx.c










Sun Release 4.1         Last change: UCL                        1



