asterisk/codecs/ilbc/filter.h
Mark Spencer c4da749362 Add iLBC codec
git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@852 65c4cc65-6c06-0410-ace0-fbb531ad65f3
2003-04-15 04:36:52 +00:00

73 lines
2.8 KiB
C
Executable file

/******************************************************************
iLBC Speech Coder ANSI-C Source Code
filter.h
Copyright (c) 2001,
Global IP Sound AB.
All rights reserved.
******************************************************************/
#ifndef __iLBC_FILTER_H
#define __iLBC_FILTER_H
void AllPoleFilter(
float *InOut, /* (i/o) on entrance InOut[-orderCoef] to
InOut[-1] contain the state of the filter
(delayed samples). InOut[0] to
InOut[lengthInOut-1] contain the filter
input, on en exit InOut[-orderCoef] to
InOut[-1] is unchanged and InOut[0] to
InOut[lengthInOut-1] contain filtered
samples */
float *Coef,/* (i) filter coefficients, Coef[0] is assumed to
be 1.0 */
int lengthInOut,/* (i) number of input/output samples */
int orderCoef /* (i) number of filter coefficients */
);
void AllZeroFilter(
float *In, /* (i) In[0] to In[lengthInOut-1] contain filter
input samples */
float *Coef,/* (i) filter coefficients (Coef[0] is assumed
to be 1.0) */
int lengthInOut,/* (i) number of input/output samples */
int orderCoef, /* (i) number of filter coefficients */
float *Out /* (i/o) on entrance Out[-orderCoef] to Out[-1]
contain the filter state, on exit Out[0]
to Out[lengthInOut-1] contain filtered
samples */
);
void ZeroPoleFilter(
float *In, /* (i) In[0] to In[lengthInOut-1] contain filter
input samples In[-orderCoef] to In[-1]
contain state of all-zero section */
float *ZeroCoef,/* (i) filter coefficients for all-zero
section (ZeroCoef[0] is assumed to
be 1.0) */
float *PoleCoef,/* (i) filter coefficients for all-pole section
(ZeroCoef[0] is assumed to be 1.0) */
int lengthInOut,/* (i) number of input/output samples */
int orderCoef, /* (i) number of filter coefficients */
float *Out /* (i/o) on entrance Out[-orderCoef] to Out[-1]
contain state of all-pole section. On exit
Out[0] to Out[lengthInOut-1] contain
filtered samples */
);
void DownSample (
float *In, /* (i) input samples */
float *Coef, /* (i) filter coefficients */
int lengthIn, /* (i) number of input samples */
float *state, /* (i) filter state */
float *Out /* (o) downsampled output */
);
#endif