filters.h

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00001 /* Copyright (C) 2002 Jean-Marc Valin */
00006 /*
00007    Redistribution and use in source and binary forms, with or without
00008    modification, are permitted provided that the following conditions
00009    are met:
00010    
00011    - Redistributions of source code must retain the above copyright
00012    notice, this list of conditions and the following disclaimer.
00013    
00014    - Redistributions in binary form must reproduce the above copyright
00015    notice, this list of conditions and the following disclaimer in the
00016    documentation and/or other materials provided with the distribution.
00017    
00018    - Neither the name of the Xiph.org Foundation nor the names of its
00019    contributors may be used to endorse or promote products derived from
00020    this software without specific prior written permission.
00021    
00022    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
00023    ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
00024    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
00025    A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
00026    CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
00027    EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
00028    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
00029    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
00030    LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
00031    NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
00032    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00033 */
00034 
00035 #ifndef FILTERS_H
00036 #define FILTERS_H
00037 
00038 #include "misc.h"
00039 
00040 spx_word16_t compute_rms(const spx_sig_t *x, int len);
00041 void signal_mul(const spx_sig_t *x, spx_sig_t *y, spx_word32_t scale, int len);
00042 void signal_div(const spx_sig_t *x, spx_sig_t *y, spx_word32_t scale, int len);
00043 
00044 #ifdef FIXED_POINT
00045 
00046 int normalize16(const spx_sig_t *x, spx_word16_t *y, spx_sig_t max_scale, int len);
00047 
00048 #endif
00049 
00051 typedef struct {
00052    int   last_pitch;
00053    spx_word16_t last_pitch_gain[3];
00054    spx_word16_t smooth_gain;
00055 } CombFilterMem;
00056 
00057 
00058 void qmf_decomp(const spx_word16_t *xx, const spx_word16_t *aa, spx_sig_t *, spx_sig_t *y2, int N, int M, spx_word16_t *mem, char *stack);
00059 void fir_mem_up(const spx_sig_t *x, const spx_word16_t *a, spx_sig_t *y, int N, int M, spx_word32_t *mem, char *stack);
00060 
00061 
00062 void filter_mem2(const spx_sig_t *x, const spx_coef_t *num, const spx_coef_t *den, spx_sig_t *y, int N, int ord, spx_mem_t *mem);
00063 void fir_mem2(const spx_sig_t *x, const spx_coef_t *num, spx_sig_t *y, int N, int ord, spx_mem_t *mem);
00064 void iir_mem2(const spx_sig_t *x, const spx_coef_t *den, spx_sig_t *y, int N, int ord, spx_mem_t *mem);
00065 
00066 /* Apply bandwidth expansion on LPC coef */
00067 void bw_lpc(spx_word16_t , const spx_coef_t *lpc_in, spx_coef_t *lpc_out, int order);
00068 
00069 
00070 
00071 void syn_percep_zero(const spx_sig_t *x, const spx_coef_t *ak, const spx_coef_t *awk1, const spx_coef_t *awk2, spx_sig_t *y, int N, int ord, char *stack);
00072 
00073 void residue_percep_zero(const spx_sig_t *xx, const spx_coef_t *ak, const spx_coef_t *awk1, const spx_coef_t *awk2, spx_sig_t *y, int N, int ord, char *stack);
00074 
00075 void compute_impulse_response(const spx_coef_t *ak, const spx_coef_t *awk1, const spx_coef_t *awk2, spx_word16_t *y, int N, int ord, char *stack);
00076 
00077 void comb_filter_mem_init (CombFilterMem *mem);
00078 
00079 void comb_filter(
00080 spx_sig_t *exc,          /*decoded excitation*/
00081 spx_sig_t *new_exc,      /*enhanced excitation*/
00082 spx_coef_t *ak,           /*LPC filter coefs*/
00083 int p,               /*LPC order*/
00084 int nsf,             /*sub-frame size*/
00085 int pitch,           /*pitch period*/
00086 spx_word16_t *pitch_gain,   /*pitch gain (3-tap)*/
00087 spx_word16_t  comb_gain,    /*gain of comb filter*/
00088 CombFilterMem *mem
00089 );
00090 
00091 
00092 #endif

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