FreeCalypso > hg > gsm-codec-lib

annotate libgsmefr/residu.c @ 478:936a08cc73ce

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
doc/AMR-library-API: describe the decoder
author Mychaela Falconia <falcon@freecalypso.org>
date Sun, 19 May 2024 21:32:31 +0000
parents de9dc80c1312
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
53
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1 /*************************************************************************
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
2 *
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
3 * FUNCTION: Residu
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
4 *
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
5 * PURPOSE: Computes the LP residual.
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
6 *
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
7 * DESCRIPTION:
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
8 * The LP residual is computed by filtering the input speech through
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
9 * the LP inverse filter A(z).
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
10 *
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
11 *************************************************************************/
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
12
91
de9dc80c1312 libgsmefr: residu.c compiles
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
13 #include "gsm_efr.h"
53
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
14 #include "typedef.h"
91
de9dc80c1312 libgsmefr: residu.c compiles
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
15 #include "namespace.h"
53
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
16 #include "basic_op.h"
91
de9dc80c1312 libgsmefr: residu.c compiles
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
17 #include "no_count.h"
de9dc80c1312 libgsmefr: residu.c compiles
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
18 #include "sig_proc.h"
53
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
19
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
20 /* m = LPC order == 10 */
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
21 #define m 10
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
22
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
23 void Residu (
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
24 Word16 a[], /* (i) : prediction coefficients */
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
25 Word16 x[], /* (i) : speech signal */
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
26 Word16 y[], /* (o) : residual signal */
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
27 Word16 lg /* (i) : size of filtering */
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
28 )
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
29 {
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
30 Word16 i, j;
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
31 Word32 s;
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
32
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
33 for (i = 0; i < lg; i++)
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
34 {
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
35 s = L_mult (x[i], a[0]);
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
36 for (j = 1; j <= m; j++)
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
37 {
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
38 s = L_mac (s, a[j], x[i - j]);
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
39 }
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
40 s = L_shl (s, 3);
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
41 y[i] = round (s); move16 ();
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
42 }
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
43 return;
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
44 }