Asterisk - The Open Source Telephony Project  18.5.0
Functions
filter.h File Reference
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Functions

void AllPoleFilter (float *InOut, float *Coef, int lengthInOut, int orderCoef)
 
void AllZeroFilter (float *In, float *Coef, int lengthInOut, int orderCoef, float *Out)
 
void DownSample (float *In, float *Coef, int lengthIn, float *state, float *Out)
 
void ZeroPoleFilter (float *In, float *ZeroCoef, float *PoleCoef, int lengthInOut, int orderCoef, float *Out)
 

Function Documentation

◆ AllPoleFilter()

void AllPoleFilter ( float *  InOut,
float *  Coef,
int  lengthInOut,
int  orderCoef 
)

Definition at line 19 of file filter.c.

Referenced by AbsQuantW(), iCBSearch(), and ZeroPoleFilter().

32  {
33  int n,k;
34 
35  for(n=0;n<lengthInOut;n++){
36  for(k=1;k<=orderCoef;k++){
37  *InOut -= Coef[k]*InOut[-k];
38 
39 
40 
41 
42 
43  }
44  InOut++;
45  }
46  }

◆ AllZeroFilter()

void AllZeroFilter ( float *  In,
float *  Coef,
int  lengthInOut,
int  orderCoef,
float *  Out 
)

Definition at line 52 of file filter.c.

Referenced by ZeroPoleFilter().

63  {
64  int n,k;
65 
66  for(n=0;n<lengthInOut;n++){
67  *Out = Coef[0]*In[0];
68  for(k=1;k<=orderCoef;k++){
69  *Out += Coef[k]*In[-k];
70  }
71  Out++;
72  In++;
73  }
74  }

◆ DownSample()

void DownSample ( float *  In,
float *  Coef,
int  lengthIn,
float *  state,
float *  Out 
)

Definition at line 110 of file filter.c.

References DELAY_DS, FACTOR_DS, FILTERORDER_DS, and stop.

Referenced by enhancerInterface().

116  {
117  float o;
118  float *Out_ptr = Out;
119  float *Coef_ptr, *In_ptr;
120  float *state_ptr;
121  int i, j, stop;
122 
123  /* LP filter and decimate at the same time */
124 
125  for (i = DELAY_DS; i < lengthIn; i+=FACTOR_DS)
126  {
127  Coef_ptr = &Coef[0];
128  In_ptr = &In[i];
129  state_ptr = &state[FILTERORDER_DS-2];
130 
131  o = (float)0.0;
132 
133  stop = (i < FILTERORDER_DS) ? i + 1 : FILTERORDER_DS;
134 
135  for (j = 0; j < stop; j++)
136  {
137  o += *Coef_ptr++ * (*In_ptr--);
138  }
139  for (j = i + 1; j < FILTERORDER_DS; j++)
140  {
141  o += *Coef_ptr++ * (*state_ptr--);
142  }
143 
144 
145 
146 
147 
148 
149  *Out_ptr++ = o;
150  }
151 
152  /* Get the last part (use zeros as input for the future) */
153 
154  for (i=(lengthIn+FACTOR_DS); i<(lengthIn+DELAY_DS);
155  i+=FACTOR_DS) {
156 
157  o=(float)0.0;
158 
159  if (i<lengthIn) {
160  Coef_ptr = &Coef[0];
161  In_ptr = &In[i];
162  for (j=0; j<FILTERORDER_DS; j++) {
163  o += *Coef_ptr++ * (*Out_ptr--);
164  }
165  } else {
166  Coef_ptr = &Coef[i-lengthIn];
167  In_ptr = &In[lengthIn-1];
168  for (j=0; j<FILTERORDER_DS-(i-lengthIn); j++) {
169  o += *Coef_ptr++ * (*In_ptr--);
170  }
171  }
172  *Out_ptr++ = o;
173  }
174  }
unsigned int stop
Definition: app_meetme.c:1096
#define FILTERORDER_DS
Definition: iLBC_define.h:94
#define FACTOR_DS
Definition: iLBC_define.h:96
#define DELAY_DS
Definition: iLBC_define.h:95

◆ ZeroPoleFilter()

void ZeroPoleFilter ( float *  In,
float *  ZeroCoef,
float *  PoleCoef,
int  lengthInOut,
int  orderCoef,
float *  Out 
)

Definition at line 80 of file filter.c.

References AllPoleFilter(), and AllZeroFilter().

Referenced by StateConstructW(), and StateSearchW().

101  {
102  AllZeroFilter(In,ZeroCoef,lengthInOut,orderCoef,Out);
103  AllPoleFilter(Out,PoleCoef,lengthInOut,orderCoef);
104  }
void AllZeroFilter(float *In, float *Coef, int lengthInOut, int orderCoef, float *Out)
Definition: filter.c:52
void AllPoleFilter(float *InOut, float *Coef, int lengthInOut, int orderCoef)
Definition: filter.c:19