FreeCalypso > hg > gsm-codec-lib

annotate libtwamr/az_lsp.h @ 461:a53225b44ea5

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
further refinement of build system: follow general free sw standards as much as possible
author Mychaela Falconia <falcon@freecalypso.org>
date Sat, 11 May 2024 07:09:59 +0000
parents 54f6bc41ed10
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
253
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1 /*
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
2 ********************************************************************************
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
3 *
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
4 * GSM AMR-NB speech codec R98 Version 7.6.0 December 12, 2001
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
5 * R99 Version 3.3.0
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
6 * REL-4 Version 4.1.0
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
7 *
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
8 ********************************************************************************
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
9 *
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
10 * File : az_lsp.h
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
11 *
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
12 ********************************************************************************
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
13 */
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
14 #ifndef az_lsp_h
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
15 #define az_lsp_h "$Id $"
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
16
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
17 /*
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
18 ********************************************************************************
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
19 * INCLUDE FILES
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
20 ********************************************************************************
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
21 */
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
22 #include "typedef.h"
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
23
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
24 /*
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
25 ********************************************************************************
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
26 * DEFINITION OF DATA TYPES
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
27 ********************************************************************************
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
28 */
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
29
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
30 /*
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
31 ********************************************************************************
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
32 * DECLARATION OF PROTOTYPES
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
33 ********************************************************************************
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
34 */
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
35 /*
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
36 **************************************************************************
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
37 *
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
38 * Function : Az_lsp
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
39 * Purpose : Compute the LSPs from the LP coefficients
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
40 * Description : - The sum and difference filters are computed
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
41 * and divided by 1+z^{-1} and 1-z^{-1}, respectively.
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
42 *
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
43 * f1[i] = a[i] + a[11-i] - f1[i-1] ; i=1,...,5
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
44 * f2[i] = a[i] - a[11-i] + f2[i-1] ; i=1,...,5
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
45 *
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
46 * - The roots of F1(z) and F2(z) are found using
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
47 * Chebyshev polynomial evaluation. The polynomials
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
48 * are evaluated at 60 points regularly spaced in the
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
49 * frequency domain. The sign change interval is
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
50 * subdivided 4 times to better track the root. The
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
51 * LSPs are found in the cosine domain [1,-1].
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
52 *
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
53 * - If less than 10 roots are found, the LSPs from
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
54 * the past frame are used.
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
55 * Returns : void
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
56 *
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
57 **************************************************************************
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
58 */
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
59 void Az_lsp (
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
60 Word16 a[], /* (i) : predictor coefficients (MP1) */
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
61 Word16 lsp[], /* (o) : line spectral pairs (M) */
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
62 Word16 old_lsp[] /* (i) : old lsp[] (in case not found 10 roots) (M)*/
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
63 );
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
64
54f6bc41ed10 libtwamr: integrate a* modules
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
65 #endif