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authorkpfleming <kpfleming@f38db490-d61c-443f-a65b-d21fe96a405b>2008-03-26 17:10:28 +0000
committerkpfleming <kpfleming@f38db490-d61c-443f-a65b-d21fe96a405b>2008-03-26 17:10:28 +0000
commitadfd7f5f1374a6b0d8b60a43684d5ec4dff51874 (patch)
treeed528d6e40b53ec5f3c552e8397f98e471c489db /codecs/ilbc/lsf.c
parent97619eccb1ddd6771755f632ace40f4119743c60 (diff)
Merged revisions 110880 via svnmerge from
https://origsvn.digium.com/svn/asterisk/branches/1.4 ................ r110880 | kpfleming | 2008-03-26 09:42:35 -0700 (Wed, 26 Mar 2008) | 10 lines Merged revisions 110869 via svnmerge from https://origsvn.digium.com/svn/asterisk/branches/1.2 ........ r110869 | kpfleming | 2008-03-26 08:53:46 -0700 (Wed, 26 Mar 2008) | 2 lines due to licensing restrictions, we cannot distribute the source code for iLBC encoding and decoding... so remove it, and add instructions on how the user can obtain it themselves ........ ................ git-svn-id: http://svn.digium.com/svn/asterisk/trunk@110881 f38db490-d61c-443f-a65b-d21fe96a405b
Diffstat (limited to 'codecs/ilbc/lsf.c')
-rw-r--r--codecs/ilbc/lsf.c264
1 files changed, 0 insertions, 264 deletions
diff --git a/codecs/ilbc/lsf.c b/codecs/ilbc/lsf.c
deleted file mode 100644
index 055c21cb5..000000000
--- a/codecs/ilbc/lsf.c
+++ /dev/null
@@ -1,264 +0,0 @@
-
-/******************************************************************
-
- iLBC Speech Coder ANSI-C Source Code
-
- lsf.c
-
- Copyright (C) The Internet Society (2004).
- All Rights Reserved.
-
-******************************************************************/
-
-#include <string.h>
-#include <math.h>
-
-#include "iLBC_define.h"
-#include "lsf.h"
-
-/*----------------------------------------------------------------*
- * conversion from lpc coefficients to lsf coefficients
- *---------------------------------------------------------------*/
-
-void a2lsf(
- float *freq,/* (o) lsf coefficients */
- float *a /* (i) lpc coefficients */
-){
- float steps[LSF_NUMBER_OF_STEPS] =
- {(float)0.00635, (float)0.003175, (float)0.0015875,
- (float)0.00079375};
- float step;
- int step_idx;
- int lsp_index;
- float p[LPC_HALFORDER];
- float q[LPC_HALFORDER];
- float p_pre[LPC_HALFORDER];
-
-
- float q_pre[LPC_HALFORDER];
- float old_p, old_q, *old;
- float *pq_coef;
- float omega, old_omega;
- int i;
- float hlp, hlp1, hlp2, hlp3, hlp4, hlp5;
-
- for (i=0; i<LPC_HALFORDER; i++) {
- p[i] = (float)-1.0 * (a[i + 1] + a[LPC_FILTERORDER - i]);
- q[i] = a[LPC_FILTERORDER - i] - a[i + 1];
- }
-
- p_pre[0] = (float)-1.0 - p[0];
- p_pre[1] = - p_pre[0] - p[1];
- p_pre[2] = - p_pre[1] - p[2];
- p_pre[3] = - p_pre[2] - p[3];
- p_pre[4] = - p_pre[3] - p[4];
- p_pre[4] = p_pre[4] / 2;
-
- q_pre[0] = (float)1.0 - q[0];
- q_pre[1] = q_pre[0] - q[1];
- q_pre[2] = q_pre[1] - q[2];
- q_pre[3] = q_pre[2] - q[3];
- q_pre[4] = q_pre[3] - q[4];
- q_pre[4] = q_pre[4] / 2;
-
- omega = 0.0;
- old_omega = 0.0;
-
- old_p = FLOAT_MAX;
- old_q = FLOAT_MAX;
-
- /* Here we loop through lsp_index to find all the
- LPC_FILTERORDER roots for omega. */
-
- for (lsp_index = 0; lsp_index<LPC_FILTERORDER; lsp_index++) {
-
- /* Depending on lsp_index being even or odd, we
- alternatively solve the roots for the two LSP equations. */
-
-
- if ((lsp_index & 0x1) == 0) {
- pq_coef = p_pre;
- old = &old_p;
- } else {
- pq_coef = q_pre;
- old = &old_q;
- }
-
- /* Start with low resolution grid */
-
- for (step_idx = 0, step = steps[step_idx];
- step_idx < LSF_NUMBER_OF_STEPS;){
-
-
-
- /* cos(10piw) + pq(0)cos(8piw) + pq(1)cos(6piw) +
- pq(2)cos(4piw) + pq(3)cod(2piw) + pq(4) */
-
- hlp = (float)cos(omega * TWO_PI);
- hlp1 = (float)2.0 * hlp + pq_coef[0];
- hlp2 = (float)2.0 * hlp * hlp1 - (float)1.0 +
- pq_coef[1];
- hlp3 = (float)2.0 * hlp * hlp2 - hlp1 + pq_coef[2];
- hlp4 = (float)2.0 * hlp * hlp3 - hlp2 + pq_coef[3];
- hlp5 = hlp * hlp4 - hlp3 + pq_coef[4];
-
-
- if (((hlp5 * (*old)) <= 0.0) || (omega >= 0.5)){
-
- if (step_idx == (LSF_NUMBER_OF_STEPS - 1)){
-
- if (fabs(hlp5) >= fabs(*old)) {
- freq[lsp_index] = omega - step;
- } else {
- freq[lsp_index] = omega;
- }
-
-
- if ((*old) >= 0.0){
- *old = (float)-1.0 * FLOAT_MAX;
- } else {
- *old = FLOAT_MAX;
- }
-
- omega = old_omega;
- step_idx = 0;
-
- step_idx = LSF_NUMBER_OF_STEPS;
- } else {
-
- if (step_idx == 0) {
- old_omega = omega;
- }
-
- step_idx++;
- omega -= steps[step_idx];
-
- /* Go back one grid step */
-
- step = steps[step_idx];
- }
- } else {
-
- /* increment omega until they are of different sign,
- and we know there is at least one root between omega
- and old_omega */
- *old = hlp5;
- omega += step;
- }
-
-
- }
- }
-
- for (i = 0; i<LPC_FILTERORDER; i++) {
- freq[i] = freq[i] * TWO_PI;
- }
-}
-
-/*----------------------------------------------------------------*
- * conversion from lsf coefficients to lpc coefficients
- *---------------------------------------------------------------*/
-
-void lsf2a(
- float *a_coef, /* (o) lpc coefficients */
- float *freq /* (i) lsf coefficients */
-){
- int i, j;
- float hlp;
- float p[LPC_HALFORDER], q[LPC_HALFORDER];
- float a[LPC_HALFORDER + 1], a1[LPC_HALFORDER],
- a2[LPC_HALFORDER];
- float b[LPC_HALFORDER + 1], b1[LPC_HALFORDER],
- b2[LPC_HALFORDER];
-
- for (i=0; i<LPC_FILTERORDER; i++) {
- freq[i] = freq[i] * PI2;
- }
-
- /* Check input for ill-conditioned cases. This part is not
- found in the TIA standard. It involves the following 2 IF
- blocks. If "freq" is judged ill-conditioned, then we first
- modify freq[0] and freq[LPC_HALFORDER-1] (normally
- LPC_HALFORDER = 10 for LPC applications), then we adjust
- the other "freq" values slightly */
-
-
- if ((freq[0] <= 0.0) || (freq[LPC_FILTERORDER - 1] >= 0.5)){
-
-
- if (freq[0] <= 0.0) {
- freq[0] = (float)0.022;
- }
-
-
- if (freq[LPC_FILTERORDER - 1] >= 0.5) {
- freq[LPC_FILTERORDER - 1] = (float)0.499;
- }
-
- hlp = (freq[LPC_FILTERORDER - 1] - freq[0]) /
- (float) (LPC_FILTERORDER - 1);
-
- for (i=1; i<LPC_FILTERORDER; i++) {
- freq[i] = freq[i - 1] + hlp;
- }
-
-
- }
-
- memset(a1, 0, LPC_HALFORDER*sizeof(float));
- memset(a2, 0, LPC_HALFORDER*sizeof(float));
- memset(b1, 0, LPC_HALFORDER*sizeof(float));
- memset(b2, 0, LPC_HALFORDER*sizeof(float));
- memset(a, 0, (LPC_HALFORDER+1)*sizeof(float));
- memset(b, 0, (LPC_HALFORDER+1)*sizeof(float));
-
- /* p[i] and q[i] compute cos(2*pi*omega_{2j}) and
- cos(2*pi*omega_{2j-1} in eqs. 4.2.2.2-1 and 4.2.2.2-2.
- Note that for this code p[i] specifies the coefficients
- used in .Q_A(z) while q[i] specifies the coefficients used
- in .P_A(z) */
-
- for (i=0; i<LPC_HALFORDER; i++) {
- p[i] = (float)cos(TWO_PI * freq[2 * i]);
- q[i] = (float)cos(TWO_PI * freq[2 * i + 1]);
- }
-
- a[0] = 0.25;
- b[0] = 0.25;
-
- for (i= 0; i<LPC_HALFORDER; i++) {
- a[i + 1] = a[i] - 2 * p[i] * a1[i] + a2[i];
- b[i + 1] = b[i] - 2 * q[i] * b1[i] + b2[i];
- a2[i] = a1[i];
- a1[i] = a[i];
- b2[i] = b1[i];
- b1[i] = b[i];
- }
-
- for (j=0; j<LPC_FILTERORDER; j++) {
-
- if (j == 0) {
- a[0] = 0.25;
- b[0] = -0.25;
- } else {
- a[0] = b[0] = 0.0;
- }
-
- for (i=0; i<LPC_HALFORDER; i++) {
- a[i + 1] = a[i] - 2 * p[i] * a1[i] + a2[i];
- b[i + 1] = b[i] - 2 * q[i] * b1[i] + b2[i];
- a2[i] = a1[i];
- a1[i] = a[i];
- b2[i] = b1[i];
- b1[i] = b[i];
- }
-
- a_coef[j + 1] = 2 * (a[LPC_HALFORDER] + b[LPC_HALFORDER]);
- }
-
- a_coef[0] = 1.0;
-
-
-}
-
-