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comparison libtwamr/hp_max.c @ 379:176a44ff94a1

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libtwamr: integrate hp_max.c
author Mychaela Falconia <falcon@freecalypso.org>
date Mon, 06 May 2024 05:10:03 +0000
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378:ccba5812fa44 379:176a44ff94a1
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 : hp_max.c
11 * Purpose : Find the maximum correlation of scal_sig[] in a given
12 * delay range.
13 *
14 ********************************************************************************
15 */
16
17 /*
18 ********************************************************************************
19 * MODULE INCLUDE FILE AND VERSION ID
20 ********************************************************************************
21 */
22 #include "namespace.h"
23 #include "hp_max.h"
24
25 /*
26 ********************************************************************************
27 * INCLUDE FILES
28 ********************************************************************************
29 */
30 #include "typedef.h"
31 #include "basic_op.h"
32 #include "oper_32b.h"
33 #include "no_count.h"
34 #include "cnst.h"
35
36 /*
37 ********************************************************************************
38 * PUBLIC PROGRAM CODE
39 ********************************************************************************
40 */
41 Word16 hp_max (
42 Word32 corr[], /* i : correlation vector. */
43 Word16 scal_sig[], /* i : scaled signal. */
44 Word16 L_frame, /* i : length of frame to compute pitch */
45 Word16 lag_max, /* i : maximum lag */
46 Word16 lag_min, /* i : minimum lag */
47 Word16 *cor_hp_max) /* o : max high-pass filtered norm. correlation */
48 {
49 Word16 i;
50 Word16 *p, *p1;
51 Word32 max, t0, t1;
52 Word16 max16, t016, cor_max;
53 Word16 shift, shift1, shift2;
54
55 max = MIN_32; move32 ();
56 t0 = 0L; move32 ();
57
58 for (i = lag_max-1; i > lag_min; i--)
59 {
60 /* high-pass filtering */
61 t0 = L_sub (L_sub(L_shl(corr[-i], 1), corr[-i-1]), corr[-i+1]);
62 t0 = L_abs (t0);
63
64 test ();
65 if (L_sub (t0, max) >= 0)
66 {
67 max = t0; move32 ();
68 }
69 }
70
71 /* compute energy */
72 p = scal_sig; move16 ();
73 p1 = &scal_sig[0]; move16 ();
74 t0 = 0L; move32 ();
75 for (i = 0; i < L_frame; i++, p++, p1++)
76 {
77 t0 = L_mac (t0, *p, *p1);
78 }
79
80 p = scal_sig; move16 ();
81 p1 = &scal_sig[-1]; move16 ();
82 t1 = 0L; move32 ();
83 for (i = 0; i < L_frame; i++, p++, p1++)
84 {
85 t1 = L_mac (t1, *p, *p1);
86 }
87
88 /* high-pass filtering */
89 t0 = L_sub(L_shl(t0, 1), L_shl(t1, 1));
90 t0 = L_abs (t0);
91
92 /* max/t0 */
93 shift1 = sub(norm_l(max), 1);
94 max16 = extract_h(L_shl(max, shift1));
95 shift2 = norm_l(t0);
96 t016 = extract_h(L_shl(t0, shift2));
97
98 test ();
99 if (t016 != 0)
100 {
101 cor_max = div_s(max16, t016);
102 }
103 else
104 {
105 cor_max = 0; move16 ();
106 }
107
108 shift = sub(shift1, shift2);
109
110 test ();
111 if (shift >= 0)
112 {
113 *cor_hp_max = shr(cor_max, shift); move16 (); /* Q15 */
114 }
115 else
116 {
117 *cor_hp_max = shl(cor_max, negate(shift)); move16 (); /* Q15 */
118 }
119
120 return 0;
121 }