/* * SpanDSP - a series of DSP components for telephony * * fir.h - General telephony FIR routines * * Written by Steve Underwood <steveu@coppice.org> * * Copyright (C) 2002 Steve Underwood * * All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2, as * published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * * $Id: fir.h,v 1.11 2007/04/08 08:16:17 steveu Exp $ *//*! \page fir_page FIR filtering\section fir_page_sec_1 What does it do????.\section fir_page_sec_2 How does it work????.*/#if !defined(_SPANDSP_FIR_H_)#define _SPANDSP_FIR_H_#if defined(USE_MMX)  ||  defined(USE_SSE2)#include "mmx.h"#endif/*!    16 bit integer FIR descriptor. This defines the working state for a single    instance of an FIR filter using 16 bit integer coefficients.*/typedef struct{    int taps;    int curr_pos;    const int16_t *coeffs;    int16_t *history;} fir16_state_t;/*!    32 bit integer FIR descriptor. This defines the working state for a single    instance of an FIR filter using 32 bit integer coefficients, and filtering    16 bit integer data.*/typedef struct{    int taps;    int curr_pos;    const int32_t *coeffs;    int16_t *history;} fir32_state_t;/*!    Floating point FIR descriptor. This defines the working state for a single    instance of an FIR filter using floating point coefficients and data.*/typedef struct{    int taps;    int curr_pos;    const float *coeffs;    float *history;} fir_float_state_t;#if defined(__cplusplus)extern "C"{#endifstatic __inline__ const int16_t *fir16_create(fir16_state_t *fir,                                              const int16_t *coeffs,                                              int taps){    fir->taps = taps;    fir->curr_pos = taps - 1;    fir->coeffs = coeffs;#if defined(USE_MMX)  ||  defined(USE_SSE2)    if ((fir->history = malloc(2*taps*sizeof(int16_t))))        memset(fir->history, 0, 2*taps*sizeof(int16_t));#else    if ((fir->history = (int16_t *) malloc(taps*sizeof(int16_t))))        memset(fir->history, 0, taps*sizeof(int16_t));#endif    return fir->history;}/*- End of function --------------------------------------------------------*/static __inline__ void fir16_flush(fir16_state_t *fir){#if defined(USE_MMX)  ||  defined(USE_SSE2)    memset(fir->history, 0, 2*fir->taps*sizeof(int16_t));#else    memset(fir->history, 0, fir->taps*sizeof(int16_t));#endif}/*- End of function --------------------------------------------------------*/static __inline__ void fir16_free(fir16_state_t *fir){    free(fir->history);}/*- End of function --------------------------------------------------------*/static __inline__ int16_t fir16(fir16_state_t *fir, int16_t sample){    int i;    int32_t y;#if defined(USE_MMX)    mmx_t *mmx_coeffs;    mmx_t *mmx_hist;    fir->history[fir->curr_pos] = sample;    fir->history[fir->curr_pos + fir->taps] = sample;    mmx_coeffs = (mmx_t *) fir->coeffs;    mmx_hist = (mmx_t *) &fir->history[fir->curr_pos];    i = fir->taps;    pxor_r2r(mm4, mm4);    /* 8 samples per iteration, so the filter must be a multiple of 8 long. */    while (i > 0)    {        movq_m2r(mmx_coeffs[0], mm0);        movq_m2r(mmx_coeffs[1], mm2);        movq_m2r(mmx_hist[0], mm1);        movq_m2r(mmx_hist[1], mm3);        mmx_coeffs += 2;        mmx_hist += 2;        pmaddwd_r2r(mm1, mm0);        pmaddwd_r2r(mm3, mm2);        paddd_r2r(mm0, mm4);        paddd_r2r(mm2, mm4);        i -= 8;    }    movq_r2r(mm4, mm0);    psrlq_i2r(32, mm0);    paddd_r2r(mm0, mm4);    movd_r2m(mm4, y);    emms();#elif defined(USE_SSE2)    xmm_t *xmm_coeffs;    xmm_t *xmm_hist;    fir->history[fir->curr_pos] = sample;    fir->history[fir->curr_pos + fir->taps] = sample;    xmm_coeffs = (xmm_t *) fir->coeffs;    xmm_hist = (xmm_t *) &fir->history[fir->curr_pos];    i = fir->taps;    pxor_r2r(xmm4, xmm4);    /* 16 samples per iteration, so the filter must be a multiple of 16 long. */    while (i > 0)    {        movdqu_m2r(xmm_coeffs[0], xmm0);        movdqu_m2r(xmm_coeffs[1], xmm2);        movdqu_m2r(xmm_hist[0], xmm1);        movdqu_m2r(xmm_hist[1], xmm3);        xmm_coeffs += 2;        xmm_hist += 2;        pmaddwd_r2r(xmm1, xmm0);        pmaddwd_r2r(xmm3, xmm2);        paddd_r2r(xmm0, xmm4);        paddd_r2r(xmm2, xmm4);        i -= 16;    }    movdqa_r2r(xmm4, xmm0);    psrldq_i2r(8, xmm0);    paddd_r2r(xmm0, xmm4);    movdqa_r2r(xmm4, xmm0);    psrldq_i2r(4, xmm0);    paddd_r2r(xmm0, xmm4);    movd_r2m(xmm4, y);#else    int offset1;    int offset2;    fir->history[fir->curr_pos] = sample;    offset2 = fir->curr_pos;    offset1 = fir->taps - offset2;    y = 0;    for (i = fir->taps - 1;  i >= offset1;  i--)        y += fir->coeffs[i]*fir->history[i - offset1];    for (  ;  i >= 0;  i--)        y += fir->coeffs[i]*fir->history[i + offset2];#endif    if (fir->curr_pos <= 0)    	fir->curr_pos = fir->taps;    fir->curr_pos--;    return (int16_t) (y >> 15);}/*- End of function --------------------------------------------------------*/static __inline__ const int16_t *fir32_create(fir32_state_t *fir,                                              const int32_t *coeffs,                                              int taps){    fir->taps = taps;    fir->curr_pos = taps - 1;    fir->coeffs = coeffs;    fir->history = (int16_t *) malloc(taps*sizeof(int16_t));    if (fir->history)    	memset(fir->history, '\0', taps*sizeof(int16_t));    return fir->history;}/*- End of function --------------------------------------------------------*/static __inline__ void fir32_flush(fir32_state_t *fir){    memset(fir->history, 0, fir->taps*sizeof(int16_t));}/*- End of function --------------------------------------------------------*/static __inline__ void fir32_free(fir32_state_t *fir){    free(fir->history);}/*- End of function --------------------------------------------------------*/static __inline__ int16_t fir32(fir32_state_t *fir, int16_t sample){    int i;    int32_t y;    int offset1;    int offset2;    fir->history[fir->curr_pos] = sample;    offset2 = fir->curr_pos;    offset1 = fir->taps - offset2;    y = 0;    for (i = fir->taps - 1;  i >= offset1;  i--)        y += fir->coeffs[i]*fir->history[i - offset1];    for (  ;  i >= 0;  i--)        y += fir->coeffs[i]*fir->history[i + offset2];    if (fir->curr_pos <= 0)    	fir->curr_pos = fir->taps;    fir->curr_pos--;    return (int16_t) (y >> 15);}/*- End of function --------------------------------------------------------*/static __inline__ const float *fir_float_create(fir_float_state_t *fir,                                                const float *coeffs,    	    	    	                        int taps){    fir->taps = taps;    fir->curr_pos = taps - 1;    fir->coeffs = coeffs;    fir->history = (float *) malloc(taps*sizeof(float));    if (fir->history)        memset(fir->history, '\0', taps*sizeof(float));    return fir->history;}/*- End of function --------------------------------------------------------*/    static __inline__ void fir_float_free(fir_float_state_t *fir){    free(fir->history);}/*- End of function --------------------------------------------------------*/static __inline__ int16_t fir_float(fir_float_state_t *fir, int16_t sample){    int i;    float y;    int offset1;    int offset2;    fir->history[fir->curr_pos] = sample;    offset2 = fir->curr_pos;    offset1 = fir->taps - offset2;    y = 0;    for (i = fir->taps - 1;  i >= offset1;  i--)        y += fir->coeffs[i]*fir->history[i - offset1];    for (  ;  i >= 0;  i--)        y += fir->coeffs[i]*fir->history[i + offset2];    if (fir->curr_pos <= 0)    	fir->curr_pos = fir->taps;    fir->curr_pos--;    return  (int16_t) y;}/*- End of function --------------------------------------------------------*/#if defined(__cplusplus)}#endif#endif/*- End of file ------------------------------------------------------------*/