From 81d1b2797aa3945c529d57f9ddf6179ec2b392a4 Mon Sep 17 00:00:00 2001 From: Benny Prijono Date: Sat, 7 Apr 2007 12:47:34 +0000 Subject: Moved ilbc to third_party directory git-svn-id: http://svn.pjsip.org/repos/pjproject/branches/split-3rd-party@1169 74dad513-b988-da41-8d7b-12977e46ad98 --- third_party/ilbc/helpfun.c | 326 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 326 insertions(+) create mode 100644 third_party/ilbc/helpfun.c (limited to 'third_party/ilbc/helpfun.c') diff --git a/third_party/ilbc/helpfun.c b/third_party/ilbc/helpfun.c new file mode 100644 index 00000000..1aba6578 --- /dev/null +++ b/third_party/ilbc/helpfun.c @@ -0,0 +1,326 @@ + + /****************************************************************** + + iLBC Speech Coder ANSI-C Source Code + + helpfun.c + + Copyright (C) The Internet Society (2004). + All Rights Reserved. + + ******************************************************************/ + + #include + + #include "iLBC_define.h" + #include "constants.h" + + /*----------------------------------------------------------------* + * calculation of auto correlation + *---------------------------------------------------------------*/ + + void autocorr( + float *r, /* (o) autocorrelation vector */ + const float *x, /* (i) data vector */ + int N, /* (i) length of data vector */ + int order /* largest lag for calculated + autocorrelations */ + ){ + int lag, n; + float sum; + + for (lag = 0; lag <= order; lag++) { + sum = 0; + for (n = 0; n < N - lag; n++) { + sum += x[n] * x[n+lag]; + } + r[lag] = sum; + } + + + + + + } + + /*----------------------------------------------------------------* + * window multiplication + *---------------------------------------------------------------*/ + + void window( + float *z, /* (o) the windowed data */ + const float *x, /* (i) the original data vector */ + const float *y, /* (i) the window */ + int N /* (i) length of all vectors */ + ){ + int i; + + for (i = 0; i < N; i++) { + z[i] = x[i] * y[i]; + } + } + + /*----------------------------------------------------------------* + * levinson-durbin solution for lpc coefficients + *---------------------------------------------------------------*/ + + void levdurb( + float *a, /* (o) lpc coefficient vector starting + with 1.0 */ + float *k, /* (o) reflection coefficients */ + float *r, /* (i) autocorrelation vector */ + int order /* (i) order of lpc filter */ + ){ + float sum, alpha; + int m, m_h, i; + + a[0] = 1.0; + + if (r[0] < EPS) { /* if r[0] <= 0, set LPC coeff. to zero */ + for (i = 0; i < order; i++) { + k[i] = 0; + a[i+1] = 0; + } + } else { + a[1] = k[0] = -r[1]/r[0]; + alpha = r[0] + r[1] * k[0]; + for (m = 1; m < order; m++){ + sum = r[m + 1]; + for (i = 0; i < m; i++){ + sum += a[i+1] * r[m - i]; + } + + + + + + k[m] = -sum / alpha; + alpha += k[m] * sum; + m_h = (m + 1) >> 1; + for (i = 0; i < m_h; i++){ + sum = a[i+1] + k[m] * a[m - i]; + a[m - i] += k[m] * a[i+1]; + a[i+1] = sum; + } + a[m+1] = k[m]; + } + } + } + + /*----------------------------------------------------------------* + * interpolation between vectors + *---------------------------------------------------------------*/ + + void interpolate( + float *out, /* (o) the interpolated vector */ + float *in1, /* (i) the first vector for the + interpolation */ + float *in2, /* (i) the second vector for the + interpolation */ + float coef, /* (i) interpolation weights */ + int length /* (i) length of all vectors */ + ){ + int i; + float invcoef; + + invcoef = (float)1.0 - coef; + for (i = 0; i < length; i++) { + out[i] = coef * in1[i] + invcoef * in2[i]; + } + } + + /*----------------------------------------------------------------* + * lpc bandwidth expansion + *---------------------------------------------------------------*/ + + void bwexpand( + float *out, /* (o) the bandwidth expanded lpc + coefficients */ + float *in, /* (i) the lpc coefficients before bandwidth + expansion */ + float coef, /* (i) the bandwidth expansion factor */ + int length /* (i) the length of lpc coefficient vectors */ + ){ + int i; + + + + + + float chirp; + + chirp = coef; + + out[0] = in[0]; + for (i = 1; i < length; i++) { + out[i] = chirp * in[i]; + chirp *= coef; + } + } + + /*----------------------------------------------------------------* + * vector quantization + *---------------------------------------------------------------*/ + + void vq( + float *Xq, /* (o) the quantized vector */ + int *index, /* (o) the quantization index */ + const float *CB,/* (i) the vector quantization codebook */ + float *X, /* (i) the vector to quantize */ + int n_cb, /* (i) the number of vectors in the codebook */ + int dim /* (i) the dimension of all vectors */ + ){ + int i, j; + int pos, minindex; + float dist, tmp, mindist; + + pos = 0; + mindist = FLOAT_MAX; + minindex = 0; + for (j = 0; j < n_cb; j++) { + dist = X[0] - CB[pos]; + dist *= dist; + for (i = 1; i < dim; i++) { + tmp = X[i] - CB[pos + i]; + dist += tmp*tmp; + } + + if (dist < mindist) { + mindist = dist; + minindex = j; + } + pos += dim; + } + for (i = 0; i < dim; i++) { + Xq[i] = CB[minindex*dim + i]; + } + *index = minindex; + + + + + + } + + /*----------------------------------------------------------------* + * split vector quantization + *---------------------------------------------------------------*/ + + void SplitVQ( + float *qX, /* (o) the quantized vector */ + int *index, /* (o) a vector of indexes for all vector + codebooks in the split */ + float *X, /* (i) the vector to quantize */ + const float *CB,/* (i) the quantizer codebook */ + int nsplit, /* the number of vector splits */ + const int *dim, /* the dimension of X and qX */ + const int *cbsize /* the number of vectors in the codebook */ + ){ + int cb_pos, X_pos, i; + + cb_pos = 0; + X_pos= 0; + for (i = 0; i < nsplit; i++) { + vq(qX + X_pos, index + i, CB + cb_pos, X + X_pos, + cbsize[i], dim[i]); + X_pos += dim[i]; + cb_pos += dim[i] * cbsize[i]; + } + } + + /*----------------------------------------------------------------* + * scalar quantization + *---------------------------------------------------------------*/ + + void sort_sq( + float *xq, /* (o) the quantized value */ + int *index, /* (o) the quantization index */ + float x, /* (i) the value to quantize */ + const float *cb,/* (i) the quantization codebook */ + int cb_size /* (i) the size of the quantization codebook */ + ){ + int i; + + if (x <= cb[0]) { + *index = 0; + *xq = cb[0]; + } else { + i = 0; + while ((x > cb[i]) && i < cb_size - 1) { + i++; + + + + + + } + + if (x > ((cb[i] + cb[i - 1])/2)) { + *index = i; + *xq = cb[i]; + } else { + *index = i - 1; + *xq = cb[i - 1]; + } + } + } + + /*----------------------------------------------------------------* + * check for stability of lsf coefficients + *---------------------------------------------------------------*/ + + int LSF_check( /* (o) 1 for stable lsf vectors and 0 for + nonstable ones */ + float *lsf, /* (i) a table of lsf vectors */ + int dim, /* (i) the dimension of each lsf vector */ + int NoAn /* (i) the number of lsf vectors in the + table */ + ){ + int k,n,m, Nit=2, change=0,pos; + float tmp; + static float eps=(float)0.039; /* 50 Hz */ + static float eps2=(float)0.0195; + static float maxlsf=(float)3.14; /* 4000 Hz */ + static float minlsf=(float)0.01; /* 0 Hz */ + + /* LSF separation check*/ + + for (n=0; nmaxlsf) { + lsf[pos]=maxlsf; + change=1; + } + } + } + } + + return change; + } + -- cgit v1.2.3