/****************************************************************** | |
iLBC Speech Coder ANSI-C Source Code | |
filter.h | |
Copyright (C) The Internet Society (2004). | |
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 | |