/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
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* CDDL HEADER END
*/
/*
* Copyright (c) 1992-2001 by Sun Microsystems, Inc.
* All rights reserved.
*/
#ifndef _MULTIMEDIA_FIR_H
#define _MULTIMEDIA_FIR_H
#pragma ident "%Z%%M% %I% %E% SMI"
#ifdef __cplusplus
extern "C" {
#endif
/*
* Finite Impulse Response (FIR) filter object
*
* For every input sample, the FIR filter generates an output sample:
* output = coef[0] * input +
* coef[1] * state[order - 1] +
* coef[2] * state[order - 2] +
* ...
* coef[order] * state[0]
*
* and the filter states are updated:
* state[0] = state[1]
* state[1] = state[2]
* ...
* state[order - 2] = state[order - 1]
* state[order - 1] = input
*/
class Fir {
protected:
int order; // filter order, # taps = order + 1
double *coef; // (order + 1) filter coeffs.
double *state; // "order" filter states
int delay; // actual delay between output & input
virtual void updateState(double *data, int size);
virtual void update_short(short *data, int size);
virtual int flush(short *out);
public:
virtual void resetState(void); // reset states to zero
Fir(void);
Fir(int order_in);
~Fir();
virtual int getOrder(void); // get filter order value
virtual int getNumCoefs(void); // get number of coefficients
virtual void putCoef(double *coef_in); // put coef_in in filter coef
virtual void getCoef(double *coef_out); // get filter coef
// filter "size" input samples for "size" output samples
virtual int filter_noadjust(short *in, int size, short *out);
/*
* filter "size" input samples. Output sample sequence is offset by
* group delay samples to align with the input sample sequence.
* the first call of this routine returns "size - group_delay"
* output samples. Call this routine with size = 0
* to fill the output buffer such that the total number of output
* samples is equal to the number of input samples.
*/
virtual int getFlushSize(void); // size of out[] for the last call
virtual int filter(short *in, int size, short *out);
};
#ifdef __cplusplus
}
#endif
#endif /* !_MULTIMEDIA_FIR_H */