FreeCalypso > hg > gsm-codec-lib

comparison libtwamr/d2_11pf.c @ 331:c75327562b5e

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
libtwamr: integrate d2_11pf.c
author Mychaela Falconia <falcon@freecalypso.org>
date Thu, 18 Apr 2024 22:14:40 +0000
parents
children
comparison
equal deleted inserted replaced
330:2cf33c211544 331:c75327562b5e
1 /*
2 ********************************************************************************
3 *
4 * GSM AMR-NB speech codec R98 Version 7.6.0 December 12, 2001
5 * R99 Version 3.3.0
6 * REL-4 Version 4.1.0
7 *
8 ********************************************************************************
9 *
10 * File : d2_11pf.c
11 * Purpose : Algebraic codebook decoder
12 *
13 ********************************************************************************
14 */
15
16 /*
17 ********************************************************************************
18 * MODULE INCLUDE FILE AND VERSION ID
19 ********************************************************************************
20 */
21 #include "namespace.h"
22 #include "d2_11pf.h"
23
24 /*
25 ********************************************************************************
26 * INCLUDE FILES
27 ********************************************************************************
28 */
29 #include "typedef.h"
30 #include "basic_op.h"
31 #include "no_count.h"
32 #include "cnst.h"
33
34 /*
35 ********************************************************************************
36 * LOCAL VARIABLES AND TABLES
37 ********************************************************************************
38 */
39 #define NB_PULSE 2 /* number of pulses */
40
41 /*
42 ********************************************************************************
43 * PUBLIC PROGRAM CODE
44 ********************************************************************************
45 */
46 /*************************************************************************
47 *
48 * FUNCTION: decode_2i40_11bits (decod_ACELP())
49 *
50 * PURPOSE: Algebraic codebook decoder
51 *
52 *************************************************************************/
53
54 void decode_2i40_11bits(
55 Word16 sign, /* i : signs of 2 pulses. */
56 Word16 index, /* i : Positions of the 2 pulses. */
57 Word16 cod[] /* o : algebraic (fixed) codebook excitation */
58 )
59 {
60 Word16 i, j;
61 Word16 pos[NB_PULSE];
62
63 /* Decode the positions */
64
65 j = index & 1; logic16 ();
66 index = shr(index, 1);
67 i = index & 7; logic16 ();
68
69 i = add(i, shl(i, 2)); /* pos0 =i*5+1+j*2 */
70 i = add(i, 1);
71 j = shl(j, 1);
72 pos[0] = add(i, j); move16 ();
73
74 index = shr(index, 3);
75 j = index & 3; logic16 ();
76 index = shr(index, 2);
77 i = index & 7; logic16 ();
78
79 test();
80 if (sub(j, 3) == 0)
81 {
82 i = add(i, shl(i, 2)); /* pos1 =i*5+4 */
83 pos[1] = add(i, 4); move16 ();
84 }
85 else
86 {
87 i = add(i, shl(i, 2)); /* pos1 =i*5+j */
88 pos[1] = add(i, j); move16 ();
89 }
90
91 /* decode the signs and build the codeword */
92
93 for (i = 0; i < L_SUBFR; i++) {
94 cod[i] = 0; move16 ();
95 }
96
97 for (j = 0; j < NB_PULSE; j++) {
98 i = sign & 1; logic16 ();
99 sign = shr(sign, 1);
100
101 test ();
102 if (i != 0) {
103 cod[pos[j]] = 8191; move16 (); /* +1.0 */
104 } else {
105 cod[pos[j]] = -8192; move16 (); /* -1.0 */
106 }
107 }
108
109 return;
110 }