FreeCalypso > hg > gsm-codec-lib
view libgsmefr/residu.c @ 436:e80632ccb745
simplify test program Makefiles
author | Mychaela Falconia <falcon@freecalypso.org> |
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date | Wed, 08 May 2024 05:32:27 +0000 |
parents | de9dc80c1312 |
children |
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/************************************************************************* * * FUNCTION: Residu * * PURPOSE: Computes the LP residual. * * DESCRIPTION: * The LP residual is computed by filtering the input speech through * the LP inverse filter A(z). * *************************************************************************/ #include "gsm_efr.h" #include "typedef.h" #include "namespace.h" #include "basic_op.h" #include "no_count.h" #include "sig_proc.h" /* m = LPC order == 10 */ #define m 10 void Residu ( Word16 a[], /* (i) : prediction coefficients */ Word16 x[], /* (i) : speech signal */ Word16 y[], /* (o) : residual signal */ Word16 lg /* (i) : size of filtering */ ) { Word16 i, j; Word32 s; for (i = 0; i < lg; i++) { s = L_mult (x[i], a[0]); for (j = 1; j <= m; j++) { s = L_mac (s, a[j], x[i - j]); } s = L_shl (s, 3); y[i] = round (s); move16 (); } return; }