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

void autocorr (float *r, const float *x, int N, int order)
 
void bwexpand (float *out, float *in, float coef, int length)
 
void interpolate (float *out, float *in1, float *in2, float coef, int length)
 
void levdurb (float *a, float *k, float *r, int order)
 
int LSF_check (float *lsf, int dim, int NoAn)
 
void sort_sq (float *xq, int *index, float x, const float *cb, int cb_size)
 
void SplitVQ (float *qX, int *index, float *X, const float *CB, int nsplit, const int *dim, const int *cbsize)
 
void vq (float *Xq, int *index, const float *CB, float *X, int n_cb, int dim)
 
void window (float *z, const float *x, const float *y, int N)
 

Function Documentation

◆ autocorr()

void autocorr ( float *  r,
const float *  x,
int  N,
int  order 
)

Definition at line 22 of file helpfun.c.

References order.

Referenced by SimpleAnalysis().

28  {
29  int lag, n;
30  float sum;
31 
32  for (lag = 0; lag <= order; lag++) {
33  sum = 0;
34  for (n = 0; n < N - lag; n++) {
35  sum += x[n] * x[n+lag];
36  }
37  r[lag] = sum;
38  }
39 
40 
41 
42 
43 
44  }
integer order
Definition: analys.c:66

◆ bwexpand()

void bwexpand ( float *  out,
float *  in,
float  coef,
int  length 
)

Definition at line 136 of file helpfun.c.

Referenced by DecoderInterpolateLSF(), SimpleAnalysis(), and SimpleInterpolateLSF().

143  {
144  int i;
145 
146 
147 
148 
149 
150  float chirp;
151 
152  chirp = coef;
153 
154  out[0] = in[0];
155  for (i = 1; i < length; i++) {
156  out[i] = chirp * in[i];
157  chirp *= coef;
158  }
159  }
FILE * in
Definition: utils/frame.c:33
FILE * out
Definition: utils/frame.c:33

◆ interpolate()

void interpolate ( float *  out,
float *  in1,
float *  in2,
float  coef,
int  length 
)

Definition at line 114 of file helpfun.c.

Referenced by LSFinterpolate2a_dec(), and LSFinterpolate2a_enc().

122  {
123  int i;
124  float invcoef;
125 
126  invcoef = (float)1.0 - coef;
127  for (i = 0; i < length; i++) {
128  out[i] = coef * in1[i] + invcoef * in2[i];
129  }
130  }
FILE * out
Definition: utils/frame.c:33

◆ levdurb()

void levdurb ( float *  a,
float *  k,
float *  r,
int  order 
)

Definition at line 67 of file helpfun.c.

References EPS, and order.

Referenced by SimpleAnalysis().

73  {
74  float sum, alpha;
75  int m, m_h, i;
76 
77  a[0] = 1.0;
78 
79  if (r[0] < EPS) { /* if r[0] <= 0, set LPC coeff. to zero */
80  for (i = 0; i < order; i++) {
81  k[i] = 0;
82  a[i+1] = 0;
83  }
84  } else {
85  a[1] = k[0] = -r[1]/r[0];
86  alpha = r[0] + r[1] * k[0];
87  for (m = 1; m < order; m++){
88  sum = r[m + 1];
89  for (i = 0; i < m; i++){
90  sum += a[i+1] * r[m - i];
91  }
92 
93 
94 
95 
96 
97  k[m] = -sum / alpha;
98  alpha += k[m] * sum;
99  m_h = (m + 1) >> 1;
100  for (i = 0; i < m_h; i++){
101  sum = a[i+1] + k[m] * a[m - i];
102  a[m - i] += k[m] * a[i+1];
103  a[i+1] = sum;
104  }
105  a[m+1] = k[m];
106  }
107  }
108  }
#define EPS
Definition: iLBC_define.h:111
integer order
Definition: analys.c:66
static struct test_val a

◆ LSF_check()

int LSF_check ( float *  lsf,
int  dim,
int  NoAn 
)

Definition at line 272 of file helpfun.c.

Referenced by iLBC_decode(), and LPCencode().

278  {
279  int k,n,m, Nit=2, change=0,pos;
280  static float eps=(float)0.039; /* 50 Hz */
281  static float eps2=(float)0.0195;
282  static float maxlsf=(float)3.14; /* 4000 Hz */
283  static float minlsf=(float)0.01; /* 0 Hz */
284 
285  /* LSF separation check*/
286 
287  for (n=0; n<Nit; n++) { /* Run through a couple of times */
288  for (m=0; m<NoAn; m++) { /* Number of analyses per frame */
289  for (k=0; k<(dim-1); k++) {
290  pos=m*dim+k;
291 
292  if ((lsf[pos+1]-lsf[pos])<eps) {
293 
294  if (lsf[pos+1]<lsf[pos]) {
295  lsf[pos+1]= lsf[pos]+eps2;
296  lsf[pos]= lsf[pos+1]-eps2;
297  } else {
298  lsf[pos]-=eps2;
299  lsf[pos+1]+=eps2;
300  }
301  change=1;
302 
303 
304 
305 
306 
307  }
308 
309  if (lsf[pos]<minlsf) {
310  lsf[pos]=minlsf;
311  change=1;
312  }
313 
314  if (lsf[pos]>maxlsf) {
315  lsf[pos]=maxlsf;
316  change=1;
317  }
318  }
319  }
320  }
321 
322  return change;
323  }

◆ sort_sq()

void sort_sq ( float *  xq,
int *  index,
float  x,
const float *  cb,
int  cb_size 
)

Definition at line 235 of file helpfun.c.

Referenced by AbsQuantW(), and StateSearchW().

241  {
242  int i;
243 
244  if (x <= cb[0]) {
245  *index = 0;
246  *xq = cb[0];
247  } else {
248  i = 0;
249  while ((x > cb[i]) && i < cb_size - 1) {
250  i++;
251 
252 
253 
254 
255 
256  }
257 
258  if (x > ((cb[i] + cb[i - 1])/2)) {
259  *index = i;
260  *xq = cb[i];
261  } else {
262  *index = i - 1;
263  *xq = cb[i - 1];
264  }
265  }
266  }

◆ SplitVQ()

void SplitVQ ( float *  qX,
int *  index,
float *  X,
const float *  CB,
int  nsplit,
const int *  dim,
const int *  cbsize 
)

Definition at line 209 of file helpfun.c.

References vq().

Referenced by SimplelsfQ().

218  {
219  int cb_pos, X_pos, i;
220 
221  cb_pos = 0;
222  X_pos= 0;
223  for (i = 0; i < nsplit; i++) {
224  vq(qX + X_pos, index + i, CB + cb_pos, X + X_pos,
225  cbsize[i], dim[i]);
226  X_pos += dim[i];
227  cb_pos += dim[i] * cbsize[i];
228  }
229  }
void vq(float *Xq, int *index, const float *CB, float *X, int n_cb, int dim)
Definition: helpfun.c:165

◆ vq()

void vq ( float *  Xq,
int *  index,
const float *  CB,
float *  X,
int  n_cb,
int  dim 
)

Definition at line 165 of file helpfun.c.

References FLOAT_MAX, and tmp().

Referenced by SplitVQ().

172  {
173  int i, j;
174  int pos, minindex;
175  float dist, tmp, mindist;
176 
177  pos = 0;
178  mindist = FLOAT_MAX;
179  minindex = 0;
180  for (j = 0; j < n_cb; j++) {
181  dist = X[0] - CB[pos];
182  dist *= dist;
183  for (i = 1; i < dim; i++) {
184  tmp = X[i] - CB[pos + i];
185  dist += tmp*tmp;
186  }
187 
188  if (dist < mindist) {
189  mindist = dist;
190  minindex = j;
191  }
192  pos += dim;
193  }
194  for (i = 0; i < dim; i++) {
195  Xq[i] = CB[minindex*dim + i];
196  }
197  *index = minindex;
198 
199 
200 
201 
202 
203  }
static int tmp()
Definition: bt_open.c:389
#define FLOAT_MAX
Definition: iLBC_define.h:110

◆ window()

void window ( float *  z,
const float *  x,
const float *  y,
int  N 
)

Definition at line 50 of file helpfun.c.

55  {
56  int i;
57 
58  for (i = 0; i < N; i++) {
59  z[i] = x[i] * y[i];
60  }
61  }