FreeCalypso > hg > gsm-codec-lib

annotate libgsmefr/preemph.c @ 115:5a63294fa321

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
gsmefr-cod-parse test program written
author Mychaela Falconia <falcon@freecalypso.org>
date Tue, 29 Nov 2022 22:18:33 +0000
parents 9aef9e54b19d
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 * routine preemphasis() *
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
3 * ~~~~~~~~~~~~~~~~~~~~~ *
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
4 * Preemphasis: filtering through 1 - g z^-1 *
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
5 *---------------------------------------------------------------------*/
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
6
86
9aef9e54b19d libgsmefr: preemph.c compiles
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
7 #include "gsm_efr.h"
53
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
8 #include "typedef.h"
86
9aef9e54b19d libgsmefr: preemph.c compiles
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
9 #include "namespace.h"
53
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
10 #include "basic_op.h"
86
9aef9e54b19d libgsmefr: preemph.c compiles
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
11 #include "no_count.h"
9aef9e54b19d libgsmefr: preemph.c compiles
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
12 #include "sig_proc.h"
9aef9e54b19d libgsmefr: preemph.c compiles
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
13 #include "cnst.h"
9aef9e54b19d libgsmefr: preemph.c compiles
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
14 #include "dec_state.h"
53
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
15
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
16 void preemphasis (
86
9aef9e54b19d libgsmefr: preemph.c compiles
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
17 struct EFR_decoder_state *st,
53
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
18 Word16 *signal, /* (i/o) : input signal overwritten by the output */
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
19 Word16 g, /* (i) : preemphasis coefficient */
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
20 Word16 L /* (i) : size of filtering */
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
21 )
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 Word16 *p1, *p2, temp, i;
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
24
86
9aef9e54b19d libgsmefr: preemph.c compiles
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
25 p1 = signal + L - 1;
9aef9e54b19d libgsmefr: preemph.c compiles
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
26 p2 = p1 - 1;
9aef9e54b19d libgsmefr: preemph.c compiles
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
27 temp = *p1;
53
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 for (i = 0; i <= L - 2; i++)
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
30 {
86
9aef9e54b19d libgsmefr: preemph.c compiles
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
31 *p1 = sub (*p1, mult (g, *p2--));
53
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
32 p1--;
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
33 }
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
34
86
9aef9e54b19d libgsmefr: preemph.c compiles
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
35 *p1 = sub (*p1, mult (g, st->mem_pre));
53
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
36
86
9aef9e54b19d libgsmefr: preemph.c compiles
Mychaela Falconia <falcon@freecalypso.org>
parents: 53
diff changeset
37 st->mem_pre = temp;
53
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
38
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
39 return;
49dd1ac8e75b libgsmefr: import most *.c files from ETSI source
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
40 }