FreeCalypso > hg > gsm-codec-lib

annotate libtwamr/log2.c @ 342:e42075184628

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
libtwamr: integrate q_plsf_3.tab
author Mychaela Falconia <falcon@freecalypso.org>
date Fri, 19 Apr 2024 00:57:15 +0000
parents bfe74a9edd5a
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
326
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1 /*
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
2 ********************************************************************************
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
3 *
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
4 * GSM AMR-NB speech codec R98 Version 7.6.0 December 12, 2001
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
5 * R99 Version 3.3.0
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
6 * REL-4 Version 4.1.0
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
7 *
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
8 ********************************************************************************
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
9 *
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
10 * File : log2.c
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
11 * Purpose : Computes log2(L_x)
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
12 *
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
13 ********************************************************************************
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
14 */
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
15 /*
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
16 ********************************************************************************
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
17 * MODULE INCLUDE FILE AND VERSION ID
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
18 ********************************************************************************
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
19 */
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
20 #include "namespace.h"
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
21 #include "log2.h"
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
22
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
23 /*
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
24 ********************************************************************************
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
25 * INCLUDE FILES
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
26 ********************************************************************************
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
27 */
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
28 #include "typedef.h"
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
29 #include "basic_op.h"
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
30 #include "no_count.h"
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
31
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
32 /*
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
33 ********************************************************************************
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
34 * LOCAL VARIABLES AND TABLES
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
35 ********************************************************************************
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
36 */
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
37 #include "log2.tab" /* Table for Log2() */
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
38
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
39 /*
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
40 ********************************************************************************
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
41 * PUBLIC PROGRAM CODE
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
42 ********************************************************************************
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
43 */
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
44
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
45 /*************************************************************************
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
46 *
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
47 * FUNCTION: Log2_norm()
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
48 *
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
49 * PURPOSE: Computes log2(L_x, exp), where L_x is positive and
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
50 * normalized, and exp is the normalisation exponent
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
51 * If L_x is negative or zero, the result is 0.
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
52 *
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
53 * DESCRIPTION:
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
54 * The function Log2(L_x) is approximated by a table and linear
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
55 * interpolation. The following steps are used to compute Log2(L_x)
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
56 *
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
57 * 1- exponent = 30-norm_exponent
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
58 * 2- i = bit25-b31 of L_x; 32<=i<=63 (because of normalization).
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
59 * 3- a = bit10-b24
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
60 * 4- i -=32
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
61 * 5- fraction = table[i]<<16 - (table[i] - table[i+1]) * a * 2
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
62 *
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
63 *************************************************************************/
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
64 void Log2_norm (
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
65 Word32 L_x, /* (i) : input value (normalized) */
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
66 Word16 exp, /* (i) : norm_l (L_x) */
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
67 Word16 *exponent, /* (o) : Integer part of Log2. (range: 0<=val<=30) */
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
68 Word16 *fraction /* (o) : Fractional part of Log2. (range: 0<=val<1) */
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
69 )
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
70 {
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
71 Word16 i, a, tmp;
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
72 Word32 L_y;
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
73
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
74 test ();
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
75 if (L_x <= (Word32) 0)
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
76 {
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
77 *exponent = 0; move16 ();
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
78 *fraction = 0; move16 ();
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
79 return;
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
80 }
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
81
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
82 *exponent = sub (30, exp); move16 ();
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
83
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
84 L_x = L_shr (L_x, 9);
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
85 i = extract_h (L_x); /* Extract b25-b31 */
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
86 L_x = L_shr (L_x, 1);
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
87 a = extract_l (L_x); /* Extract b10-b24 of fraction */
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
88 a = a & (Word16) 0x7fff; logic16 ();
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
89
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
90 i = sub (i, 32);
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
91
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
92 L_y = L_deposit_h (table[i]); /* table[i] << 16 */
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
93 tmp = sub (table[i], table[i + 1]); /* table[i] - table[i+1] */
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
94 L_y = L_msu (L_y, tmp, a); /* L_y -= tmp*a*2 */
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
95
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
96 *fraction = extract_h (L_y);move16 ();
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
97
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
98 return;
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
99 }
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
100
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
101 /*************************************************************************
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
102 *
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
103 * FUNCTION: Log2()
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
104 *
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
105 * PURPOSE: Computes log2(L_x), where L_x is positive.
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
106 * If L_x is negative or zero, the result is 0.
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
107 *
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
108 * DESCRIPTION:
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
109 * normalizes L_x and then calls Log2_norm().
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
110 *
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
111 *************************************************************************/
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
112 void Log2 (
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
113 Word32 L_x, /* (i) : input value */
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
114 Word16 *exponent, /* (o) : Integer part of Log2. (range: 0<=val<=30) */
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
115 Word16 *fraction /* (o) : Fractional part of Log2. (range: 0<=val<1) */
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
116 )
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
117 {
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
118 Word16 exp;
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
119
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
120 exp = norm_l (L_x);
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
121 Log2_norm (L_shl (L_x, exp), exp, exponent, fraction);
bfe74a9edd5a libtwamr: integrate log2.c
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
122 }