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comparison libtwamr/int_lpc.h @ 381:32bc48faec4b

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libtwamr: integrate int_lpc.c
author Mychaela Falconia <falcon@freecalypso.org>
date Mon, 06 May 2024 05:35:21 +0000
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380:2ed325c9a507 381:32bc48faec4b
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 : int_lpc.h
11 * Purpose : Interpolates the LSPs and converts to LPC parameters
12 *
13 ********************************************************************************
14 */
15 #ifndef int_lpc_h
16 #define int_lpc_h "$Id $"
17
18 /*
19 ********************************************************************************
20 * INCLUDE FILES
21 ********************************************************************************
22 */
23 #include "typedef.h"
24
25 /*
26 ********************************************************************************
27 * DEFINITION OF DATA TYPES
28 ********************************************************************************
29 */
30
31 /*
32 ********************************************************************************
33 * DECLARATION OF PROTOTYPES
34 ********************************************************************************
35 */
36 /*
37 **************************************************************************
38 *
39 * Function : Int_lpc_1and3
40 * Purpose : Interpolates the LSPs and converts to LPC parameters
41 * to get a different LP filter in each subframe.
42 * Description : The 20 ms speech frame is divided into 4 subframes.
43 * The LSPs are quantized and transmitted at the 2nd and
44 * 4th subframes (twice per frame) and interpolated at the
45 * 1st and 3rd subframe.
46 *
47 * |------|------|------|------|
48 * sf1 sf2 sf3 sf4
49 * F0 Fm F1
50 *
51 * sf1: 1/2 Fm + 1/2 F0 sf3: 1/2 F1 + 1/2 Fm
52 * sf2: Fm sf4: F1
53 * Returns : void
54 *
55 **************************************************************************
56 */
57 void Int_lpc_1and3 (
58 Word16 lsp_old[], /* i : LSP vector at the 4th subfr. of past frame (M) */
59 Word16 lsp_mid[], /* i : LSP vector at the 2nd subfr. of
60 present frame (M) */
61 Word16 lsp_new[], /* i : LSP vector at the 4th subfr. of
62 present frame (M) */
63 Word16 Az[] /* o : interpolated LP parameters in all subfr.
64 (AZ_SIZE) */
65 );
66
67 /*
68 **************************************************************************
69 *
70 * Function : Int_lpc_1and3_2
71 * Purpose : Interpolation of the LPC parameters. Same as the Int_lpc
72 * function but we do not recompute Az() for subframe 2 and
73 * 4 because it is already available.
74 * Returns : void
75 *
76 **************************************************************************
77 */
78 void Int_lpc_1and3_2 (
79 Word16 lsp_old[], /* i : LSP vector at the 4th subfr. of past frame (M) */
80 Word16 lsp_mid[], /* i : LSP vector at the 2nd subframe of
81 present frame (M) */
82 Word16 lsp_new[], /* i : LSP vector at the 4th subframe of
83 present frame (M) */
84 Word16 Az[] /* o :interpolated LP parameters
85 in subframes 1 and 3 (AZ_SIZE) */
86 );
87
88 /*
89 **************************************************************************
90 *
91 * Function : Int_lpc_1to3
92 * Purpose : Interpolates the LSPs and converts to LPC parameters
93 * to get a different LP filter in each subframe.
94 * Description : The 20 ms speech frame is divided into 4 subframes.
95 * The LSPs are quantized and transmitted at the 4th
96 * subframes (once per frame) and interpolated at the
97 * 1st, 2nd and 3rd subframe.
98 *
99 * |------|------|------|------|
100 * sf1 sf2 sf3 sf4
101 * F0 F1
102 *
103 * sf1: 3/4 F0 + 1/4 F1 sf3: 1/4 F0 + 3/4 F1
104 * sf2: 1/2 F0 + 1/2 F1 sf4: F1
105 * Returns : void
106 *
107 **************************************************************************
108 */
109 void Int_lpc_1to3 (
110 Word16 lsp_old[], /* i : LSP vector at the 4th SF of past frame (M) */
111 Word16 lsp_new[], /* i : LSP vector at the 4th SF of present frame (M) */
112 Word16 Az[] /* o : interpolated LP parameters in all SFs (AZ_SIZE) */
113 );
114
115 /*
116 **************************************************************************
117 *
118 * Function : Int_lpc_1to3_2
119 * Purpose : Interpolation of the LPC parameters. Same as the Int_lpc
120 * function but we do not recompute Az() for subframe 4
121 * because it is already available.
122 * Returns : void
123 *
124 **************************************************************************
125 */
126 void Int_lpc_1to3_2 (
127 Word16 lsp_old[], /* i : LSP vector at the 4th SF of past frame (M) */
128 Word16 lsp_new[], /* i : LSP vector at the 4th SF present frame (M) */
129 Word16 Az[] /* o :interpolated LP parameters in SFs 1, 2, 3
130 (AZ_SIZE) */
131 );
132
133 #endif