From 92a945abe63a2579c66257696ddda848ab5a3ea0 Mon Sep 17 00:00:00 2001 From: markster Date: Thu, 14 Oct 2004 05:15:48 +0000 Subject: Update to new iLBC codec git-svn-id: http://svn.digium.com/svn/asterisk/trunk@3997 f38db490-d61c-443f-a65b-d21fe96a405b --- codecs/ilbc/lsf.c | 516 ++++++++++++++++++++++++++++-------------------------- 1 file changed, 263 insertions(+), 253 deletions(-) (limited to 'codecs/ilbc/lsf.c') diff --git a/codecs/ilbc/lsf.c b/codecs/ilbc/lsf.c index b0429e05b..348ffe393 100755 --- a/codecs/ilbc/lsf.c +++ b/codecs/ilbc/lsf.c @@ -1,253 +1,263 @@ - -/****************************************************************** - - iLBC Speech Coder ANSI-C Source Code - - lsf.c - - Copyright (c) 2001, - Global IP Sound AB. - All rights reserved. - -******************************************************************/ - -#include -#include - -#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; -} - - + +/****************************************************************** + + iLBC Speech Coder ANSI-C Source Code + + lsf.c + + Copyright (C) The Internet Society (2004). + All Rights Reserved. + +******************************************************************/ + +#include +#include + +#include "iLBC_define.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= 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= 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