FreeCalypso > hg > gsm-codec-lib
view libtwamr/cor_h.c @ 398:df14b0c17e6d
libtwamr: integrate pred_lt.c
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Mon, 06 May 2024 19:07:10 +0000 |
parents | 5401aaf7acb0 |
children |
line wrap: on
line source
/* ***************************************************************************** * * GSM AMR-NB speech codec R98 Version 7.6.0 December 12, 2001 * R99 Version 3.3.0 * REL-4 Version 4.1.0 * ****************************************************************************** * * File : cor_h.c * Purpose : correlation functions for codebook search * ***************************************************************************** */ /* ***************************************************************************** * MODULE INCLUDE FILE AND VERSION ID ***************************************************************************** */ #include "namespace.h" #include "cor_h.h" /* ***************************************************************************** * INCLUDE FILES ***************************************************************************** */ #include "typedef.h" #include "basic_op.h" #include "no_count.h" #include "inv_sqrt.h" #include "cnst.h" /* ***************************************************************************** * PUBLIC PROGRAM CODE ***************************************************************************** */ /************************************************************************* * * FUNCTION: cor_h_x() * * PURPOSE: Computes correlation between target signal "x[]" and * impulse response"h[]". * * DESCRIPTION: * The correlation is given by: * d[n] = sum_{i=n}^{L-1} x[i] h[i-n] n=0,...,L-1 * * d[n] is normalized such that the sum of 5 maxima of d[n] corresponding * to each position track does not saturate. * *************************************************************************/ void cor_h_x ( Word16 h[], /* (i): impulse response of weighted synthesis filter */ Word16 x[], /* (i): target */ Word16 dn[], /* (o): correlation between target and h[] */ Word16 sf /* (i): scaling factor: 2 for 12.2, 1 for others */ ) { cor_h_x2(h, x, dn, sf, NB_TRACK, STEP); } /************************************************************************* * * FUNCTION: cor_h_x2() * * PURPOSE: Computes correlation between target signal "x[]" and * impulse response"h[]". * * DESCRIPTION: * See cor_h_x, d[n] can be normalized regards to sum of the * five MR122 maxima or the four MR102 maxima. * *************************************************************************/ void cor_h_x2 ( Word16 h[], /* (i): impulse response of weighted synthesis filter */ Word16 x[], /* (i): target */ Word16 dn[], /* (o): correlation between target and h[] */ Word16 sf, /* (i): scaling factor: 2 for 12.2, 1 for others */ Word16 nb_track,/* (i): the number of ACB tracks */ Word16 step /* (i): step size from one pulse position to the next in one track */ ) { Word16 i, j, k; Word32 s, y32[L_CODE], max, tot; /* first keep the result on 32 bits and find absolute maximum */ tot = 5; move32 (); for (k = 0; k < nb_track; k++) { max = 0; move32 (); for (i = k; i < L_CODE; i += step) { s = 0; move32 (); for (j = i; j < L_CODE; j++) s = L_mac (s, x[j], h[j - i]); y32[i] = s; move32 (); s = L_abs (s); test (); if (L_sub (s, max) > (Word32) 0L) max = s; move32 (); } tot = L_add (tot, L_shr (max, 1)); } j = sub (norm_l (tot), sf); for (i = 0; i < L_CODE; i++) { dn[i] = round (L_shl (y32[i], j)); move16 (); } } /************************************************************************* * * FUNCTION: cor_h() * * PURPOSE: Computes correlations of h[] needed for the codebook search; * and includes the sign information into the correlations. * * DESCRIPTION: The correlations are given by * rr[i][j] = sum_{n=i}^{L-1} h[n-i] h[n-j]; i>=j; i,j=0,...,L-1 * * and the sign information is included by * rr[i][j] = rr[i][j]*sign[i]*sign[j] * *************************************************************************/ void cor_h ( Word16 h[], /* (i) : impulse response of weighted synthesis filter */ Word16 sign[], /* (i) : sign of d[n] */ Word16 rr[][L_CODE] /* (o) : matrix of autocorrelation */ ) { Word16 i, j, k, dec, h2[L_CODE]; Word32 s; /* Scaling for maximum precision */ s = 2; move32 (); for (i = 0; i < L_CODE; i++) s = L_mac (s, h[i], h[i]); j = sub (extract_h (s), 32767); test (); if (j == 0) { for (i = 0; i < L_CODE; i++) { h2[i] = shr (h[i], 1); move16 (); } } else { s = L_shr (s, 1); k = extract_h (L_shl (Inv_sqrt (s), 7)); k = mult (k, 32440); /* k = 0.99*k */ for (i = 0; i < L_CODE; i++) { h2[i] = round (L_shl (L_mult (h[i], k), 9)); move16 (); } } /* build matrix rr[] */ s = 0; move32 (); i = L_CODE - 1; for (k = 0; k < L_CODE; k++, i--) { s = L_mac (s, h2[k], h2[k]); rr[i][i] = round (s); move16 (); } for (dec = 1; dec < L_CODE; dec++) { s = 0; move32 (); j = L_CODE - 1; i = sub (j, dec); for (k = 0; k < (L_CODE - dec); k++, i--, j--) { s = L_mac (s, h2[k], h2[k + dec]); rr[j][i] = mult (round (s), mult (sign[i], sign[j])); move16 (); rr[i][j] = rr[j][i]; move16 (); } } }