/**MAN





























































SFS                     Last change: UCL                        1






ESFILT(UCL1)      MISC. REFERENCE MANUAL PAGES       ESFILT(UCL1)



NAME
     Esfilt - interactive waveform filtering

SYNOPSIS
     Esfilt   (-I)   (-p)   (-f   filtfreq)   (-h|-l|-w|-n)   (-t
     print_title) (-i item) (-12) sfsfile

DESCRIPTION
     Esfilt is a program to demonstrate filtering of  speech  and
     other  waveforms.   Four  types of filter are built into the
     program, and can be specified by a single frequency  parame-
     ter:  high-pass,  low-pass,  wide-band-pass (300Hz), narrow-
     band-pass  (45Hz).   The  program  displays   the   original
     waveform at the top of the screen, the frequency response of
     the filter in the middle  of  the  screen,  and  the  output
     waveform  at  the  bottom of the screen.  A mouse click will
     select replay of either waveform.  The selection  of  filter
     type  and  its  frequency  are made using keyboard commands.
     Options also allow printing the display and saving the  fil-
     tered  waveform  back to the SFS file.  The RMS amplitude of
     the input and  output  waveforms  are  displayed  in  Volts,
     assuming an ADC acquisition of 16-bits in the range -5 .. +5
     V.

OPTIONS
     -I         Identify program name and version number.

     -iitem     Specify  input  Speech  or  Lx   Waveform   item.
                Default: last speech item.

     -p         Direct output to printer.  The program  does  not
                enter  interactive  mode.   The  screen  image is
                recreated for the printer using filter specifica-
                tions made using other command-line options.

     -ffiltfreq Set up initial filter frequency.  Default 1000Hz.

     -h         Specify initial filter type as High-Pass.

     -l         Specify initial filter type as Low-Pass. Default.

     -n         Specify initial filter type as Narrow-Band-Pass.

     -w         Specify initial filter type as Wide-Band-Pass.

     -tprint_title
                Specify a title to appear on the printout.  If no
                title  is given then the date and time is printed
                instead.

     -12        Identify unmarked signals as 12-bits.




SFS                     Last change: UCL                        1






ESFILT(UCL1)      MISC. REFERENCE MANUAL PAGES       ESFILT(UCL1)



MAIN MENU
     low-pass   Select low-pass filter, requests  edge  frequency
                and re-draws display.

     high-pass  Select high-pass filter, requests edge  frequency
                and re-draws display.

     narrow-band
                Select narrow-band-pass filter,  requests  centre
                frequency and re-draws display.

     wide-band  Select  wide-band-pass  filter,  requests  centre
                frequency and re-draws display.

     print      Prints display.  Requests a  print  title  before
                printing in background.

     save       Saves currently filtered waveform to SFS file.

     quit       Exits program.

MOUSE COMANDS
     middle     Replays waveform under mouse pointer.

VERSION/AUTHOR
     1.1  Mark Huckvale */

SOURCE
     /users/mark/sfs/man/../contrib/teach/esfilt.c


























SFS                     Last change: UCL                        2



