annotate libtwamr/preemph.h @ 452:6e595f7d40e2

CHANGES: document changes for the upcoming release
author Mychaela Falconia <falcon@freecalypso.org>
date Fri, 10 May 2024 03:45:47 +0000
parents 3618b5cf25a6
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
399
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1 /*
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
2 ********************************************************************************
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
3 *
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
4 * GSM AMR-NB speech codec R98 Version 7.6.0 December 12, 2001
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
5 * R99 Version 3.3.0
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
6 * REL-4 Version 4.1.0
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
7 *
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
8 ********************************************************************************
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
9 *
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
10 * File : preemph.h
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
11 * Purpose : Preemphasis filtering
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
12 * Description : Filtering through 1 - g z^-1
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
13 *
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
14 ********************************************************************************
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
15 */
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
16 #ifndef preemph_h
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
17 #define preemph_h "$Id $"
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
18
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
19 /*
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
20 ********************************************************************************
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
21 * INCLUDE FILES
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
22 ********************************************************************************
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
23 */
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
24 #include "typedef.h"
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
25
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
26 /*
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
27 ********************************************************************************
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
28 * DEFINITION OF DATA TYPES
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
29 ********************************************************************************
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
30 */
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
31 typedef struct {
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
32 Word16 mem_pre; /* filter state */
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
33 } preemphasisState;
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
34
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
35 /*
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
36 ********************************************************************************
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
37 * DECLARATION OF PROTOTYPES
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
38 ********************************************************************************
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
39 */
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
40
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
41 void preemphasis_reset (preemphasisState *st);
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
42 /* reset of preemphasis filter (i.e. set state memory to zero)
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
43 returns 0 on success
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
44 */
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
45
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
46 int preemphasis (
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
47 preemphasisState *st, /* (i/o): preemphasis filter state */
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
48 Word16 *signal, /* (i/o): input signal overwritten by the output */
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
49 Word16 g, /* (i) : preemphasis coefficient */
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
50 Word16 L /* (i) : size of filtering */
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
51 );
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
52
3618b5cf25a6 libtwamr: integrate preemph.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
53 #endif