FreeCalypso > hg > gsm-codec-lib
view libtwamr/convolve.c @ 382:693ea1d5cf1e
libtwamr: integrate int_lsf.c
author | Mychaela Falconia <falcon@freecalypso.org> |
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date | Mon, 06 May 2024 05:45:31 +0000 |
parents | e230a4a87bd8 |
children |
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/* ******************************************************************************** * * 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 : convolve.c * Purpose : Perform the convolution between two vectors x[] * : and h[] and write the result in the vector y[]. * : All vectors are of length L and only the first * : L samples of the convolution are computed. * ******************************************************************************** */ /* ******************************************************************************** * MODULE INCLUDE FILE AND VERSION ID ******************************************************************************** */ #include "namespace.h" #include "convolve.h" /* ******************************************************************************** * INCLUDE FILES ******************************************************************************** */ #include "typedef.h" #include "basic_op.h" #include "no_count.h" /* ******************************************************************************** * LOCAL VARIABLES AND TABLES ******************************************************************************** */ /* ******************************************************************************** * PUBLIC PROGRAM CODE ******************************************************************************** */ /************************************************************************* * * FUNCTION: Convolve * * PURPOSE: * Perform the convolution between two vectors x[] and h[] and * write the result in the vector y[]. All vectors are of length L * and only the first L samples of the convolution are computed. * * DESCRIPTION: * The convolution is given by * * y[n] = sum_{i=0}^{n} x[i] h[n-i], n=0,...,L-1 * *************************************************************************/ void Convolve ( Word16 x[], /* (i) : input vector */ Word16 h[], /* (i) : impulse response */ Word16 y[], /* (o) : output vector */ Word16 L /* (i) : vector size */ ) { Word16 i, n; Word32 s; for (n = 0; n < L; n++) { s = 0; move32 (); for (i = 0; i <= n; i++) { s = L_mac (s, x[i], h[n - i]); } s = L_shl (s, 3); y[n] = extract_h (s); move16 (); } return; }