filtdemo

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#! /bin/sh
# This material contains unpublished, proprietary software of
# Entropic Research Laboratory, Inc. Any reproduction, distribution,
# or publication of this work must be authorized in writing by Entropic
# Research Laboratory, Inc., and must bear the notice:
#
#    "Copyright (c) 1986-1990  Entropic Speech, Inc.
#    "Copyright (c) 1990-1991  Entropic Research Laboratory, Inc.
#                   All rights reserved"
#
# The copyright notice above does not evidence any actual or intended
# publication of this source code.
#
# @(#)filtdemo	3.15   6/18/94     ESI/ERL
#
# Written by:
# Checked by:
# Revised by: Derek Lin
#
# Brief description:  Illustrates basic filter design and filtering
#

USE_ESPS_COMMON=off
ESPS_VERBOSE=0
export USE_ESPS_COMMON
export ESPS_VERBOSE
if test `mach_type` = CONVEX -o `mach_type` = SONY_RISC -o `mach_type` = SONY_68
 then
  echo This script will fail if you do not have write permission on this directory.
 else
  if test ! -w . 
    then
	echo "You do not have write permission in this directory."
	exit 1
  fi
fi
param=./paramdemo
echo " "
echo IIR and FIR filters with various design methods are created in this 
echo demo.  Their frequency responses are generated and plotted.  Then a
echo test signal is generated and filtered using the designed filters.
echo All filters are sampled at 8000 Hz.
echo " "
echo PRESS THE "QUIT" BUTTON ON PLOTS TO CONTINUE
echo " "
############################NOTCH_FILT###########################
echo Now design a notch filter with 200 Hz wide notch at 2000 Hz.
echo " "
echo "   %notch_filt -b200 -n2000 -s8000  notch.filt"
notch_filt -b200 -n2000 -s8000  notch.filt
echo " "
echo 'Compute the spectral response of the notch filter (by using filtspec(1-ESPS))'
echo 'and plot it by using plotspec(1-ESPS) (save the response in notch.spec).'
echo " "
echo "   %filtspec -s8000 -n513 notch.filt - | tee notch.spec | plotspec -"
filtspec -s8000 -n513 notch.filt - | tee notch.spec | plotspec -t "Notch Response by notch_filt(1-ESPS)" -W "=450x400+0+0" - 
echo " "
#############################PKMC_FILT############################
cat > $param << EOF
int filt_length = 21;
float band1_edge2 = 2000.000000;
float band2_edge1 = 3200.000000;
float band1_des = 1.000000;
float band1_wt = 1.000000;
float band2_wt = 1.000000;
string filt_type = "DIFFERENTIATOR";
float samp_freq = 8000.000000;
int nbands = 2;
float band1_edge1 = 0.000000;
float band2_edge2 = 4000.000000;
float band2_des = 0.000000;
EOF
echo Now design a FIR differentiator by the Parks-McClellan algorithm
echo with 21 taps, 0 to 2000 Hz as passband and 3200 to 4000 Hz stopband
echo " "
echo "   %pkmc_filt -P$param pkmc.filt"
pkmc_filt -P$param pkmc.filt
echo " "
echo where $param is an ASCII parameter file.  The $param file 
echo is generated on the fly, and will contain appropriate design
echo parameters for all the following design examples.
echo " "
echo Compute the spectral response of the equiripple filter, and plot
echo "in linear scale. (save the response in pkmc.spec)."
echo " "
echo "   %filtspec -s 8000 -n513 -ml pkmc.filt - | tee pkmc.spec | plotspec -"
filtspec -s 8000 -n513 -ml pkmc.filt - | tee pkmc.spec | plotspec -t "FIR Equiripple Differentiator by pkmc_filt(1-ESPS)" -W  "=450x400+0+0" -  
rm $param
echo " "
##############################CB_FILT################################
cat > $param << EOF
int filt_length_L = 31;
int filt_length_S = 21;
float samp_freq = 8000.000000;
int nspec = 5;
string model = "cosine";
string push_direction = "neither";
string spec1_type = "limit";
string spec1_sense = "+";
float spec1_edge1 = 0.000000;
float spec1_edge2 = 1500.000000;
float spec1_bound1 = 1.000000;
float spec1_bound2 = 1.000000;
string spec1_hug = "hugged";
string spec1_interp = "arithmetic";
string spec2_type = "limit";
string spec2_sense = "-";
float spec2_edge1 = 0.000000;
float spec2_edge2 = 1500.000000;
float spec2_bound1 = 0.800000;
float spec2_bound2 = 0.800000;
string spec2_hug = "not hugged";
string spec2_interp = "arithmetic";
string spec3_type = "limit";
string spec3_sense = "+";
float spec3_edge1 = 1800.000000;
float spec3_edge2 = 4000.000000;
float spec3_bound1 = 0.100000;
float spec3_bound2 = 0.100000;
string spec3_hug = "not hugged";
string spec3_interp = "arithmetic";
string spec4_type = "limit";
string spec4_sense = "-";
float spec4_edge1 = 1800.000000;
float spec4_edge2 = 4000.000000;
float spec4_bound1 = -0.100000;
float spec4_bound2 = -0.100000;
string spec4_hug = "not hugged";
string spec4_interp = "arithmetic";
string spec5_type = "concave";
string spec5_sense = "-";
float spec5_edge1 = 0.000000;
float spec5_edge2 = 1500.000000;
EOF
echo Now design a lowpass FIR filter with maximally flat passband by the
echo constraint-based technique, 0 to 1500 Hz as passband, 1800 to 4000 Hz 
echo as stopband.
echo " "
echo "   %cb_filt -P$param cb.filt"
cb_filt -P$param cb.filt
echo Compute the spectral response of the maximally-flat passband filter, 
echo "and plot it.  (save the response in cb.spec)"
echo " "
echo "   %filtspec -s 8000 -n513 cb.filt - | tee cb.spec | plotspec -"  
filtspec -s 8000 -n513 cb.filt - | tee cb.spec | plotspec -y-40: -t "FIR Maximally Flat Passband by cb_filt(1-ESPS)" -W "=450x400+0+0" - 2> /dev/null
rm $param
echo " "
###################################WMSE_FILT####################
cat > $param << EOF
float samp_freq = 8000.000000;
int filt_length = 201;
int nbands = 2;
float band_edge1 = 0.000000;
float band_edge2 = 1800.000000;
float band_edge3 = 4000.000000;
float band1_des = 0.000000;
float band2_des = 1.000000;
float band1_wt = 1.000000;
float band2_wt = 1.000000;
EOF
echo Now design a highpass FIR filter by the minimum-mean square error criteria
echo with 201 taps, 0 to 1800 Hz as stopband and 1500 to 4000 Hz as passband
echo " "
echo "   %wmse_filt -P$param wmse.filt"
wmse_filt -P$param wmse.filt
echo " "
echo Compute the spectral response of the highpass filter, and plot it
echo "(save the response in wmse.spec)"
echo " "
echo "   %filtspec -s 8000 -n513 wmse.filt - | tee wmse.spec | plotspec -"
filtspec -s 8000 -n513 wmse.filt - | tee wmse.spec | plotspec -y-50: -t "FIR Lowpass with Weighted Mean Square Error Criteria by wmse_filt(1-ESPS)" -W "=450x400+0+0" -  2> /dev/null
rm $param
echo " "
##################################WIN_FILT#####################
cat >$param <<EOF
float band1_des = 0.000000;
float band2_des = 1.000000;
float band3_des = 0.000000;
float band4_des = 1.000000;
float band_edge1 = 0.000000;
float band_edge2 = 1100.000000;
float band_edge3 = 1600.000000;
float band_edge4 = 2600.000000;
float band_edge5 = 4000.000000;
float rej_db = 20.000000;
float trans_band = 100.000000;
float samp_freq = 8000.000000;
int nbands = 4;
EOF
echo Now design a multiband FIR filter by the Kaiser-Windowing method
echo with passband 1100 to 1600 Hz and 2600 to 4000 Hz.
echo " "
echo "   %win_filt -P$param win.filt"
win_filt -P$param win.filt
echo " "
echo Compute the spectral response of the multiband filter, and plot it