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comparison libtwamr/cl_ltp.c @ 406:85e9768d497f

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libtwamr: integrate cl_ltp.c
author Mychaela Falconia <falcon@freecalypso.org>
date Mon, 06 May 2024 23:32:59 +0000
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405:8fff74ca83e8 406:85e9768d497f
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 : cl_ltp.c
11 *
12 *****************************************************************************
13 */
14
15 /*
16 *****************************************************************************
17 * MODULE INCLUDE FILE AND VERSION ID
18 *****************************************************************************
19 */
20 #include "namespace.h"
21 #include "cl_ltp.h"
22
23 /*
24 *****************************************************************************
25 * INCLUDE FILES
26 *****************************************************************************
27 */
28 #include <stddef.h>
29 #include "typedef.h"
30 #include "basic_op.h"
31 #include "no_count.h"
32 #include "oper_32b.h"
33 #include "cnst.h"
34 #include "convolve.h"
35 #include "g_pitch.h"
36 #include "pred_lt.h"
37 #include "pitch_fr.h"
38 #include "enc_lag3.h"
39 #include "enc_lag6.h"
40 #include "q_gain_p.h"
41 #include "ton_stab.h"
42
43 /*
44 *****************************************************************************
45 * LOCAL VARIABLES AND TABLES
46 *****************************************************************************
47 */
48
49 /*
50 *****************************************************************************
51 * PUBLIC PROGRAM CODE
52 *****************************************************************************
53 */
54
55 /*************************************************************************
56 *
57 * Function: cl_ltp_reset
58 * Purpose: Initializes state memory to zero
59 *
60 **************************************************************************
61 */
62 void cl_ltp_reset (clLtpState *state)
63 {
64 /* Reset pitch search states */
65 Pitch_fr_reset (&state->pitchSt);
66 }
67
68 /*************************************************************************
69 *
70 * Function: cl_ltp
71 * Purpose: closed-loop fractional pitch search
72 *
73 **************************************************************************
74 */
75 int cl_ltp (
76 clLtpState *clSt, /* i/o : State struct */
77 tonStabState *tonSt, /* i/o : State struct */
78 enum Mode mode, /* i : coder mode */
79 Word16 frameOffset, /* i : Offset to subframe */
80 Word16 T_op[], /* i : Open loop pitch lags */
81 Word16 *h1, /* i : Impulse response vector Q12 */
82 Word16 *exc, /* i/o : Excitation vector Q0 */
83 Word16 res2[], /* i/o : Long term prediction residual Q0 */
84 Word16 xn[], /* i : Target vector for pitch search Q0 */
85 Word16 lsp_flag, /* i : LSP resonance flag */
86 Word16 xn2[], /* o : Target vector for codebook search Q0 */
87 Word16 y1[], /* o : Filtered adaptive excitation Q0 */
88 Word16 *T0, /* o : Pitch delay (integer part) */
89 Word16 *T0_frac, /* o : Pitch delay (fractional part) */
90 Word16 *gain_pit, /* o : Pitch gain Q14 */
91 Word16 g_coeff[], /* o : Correlations between xn, y1, & y2 */
92 Word16 **anap, /* o : Analysis parameters */
93 Word16 *gp_limit /* o : pitch gain limit */
94 )
95 {
96 Word16 i;
97 Word16 index;
98 Word32 L_temp; /* temporarily variable */
99 Word16 resu3; /* flag for upsample resolution */
100 Word16 gpc_flag;
101
102 /*----------------------------------------------------------------------*
103 * Closed-loop fractional pitch search *
104 *----------------------------------------------------------------------*/
105 *T0 = Pitch_fr(&clSt->pitchSt,
106 mode, T_op, exc, xn, h1,
107 L_SUBFR, frameOffset,
108 T0_frac, &resu3, &index); move16 ();
109
110 *(*anap)++ = index; move16 ();
111
112 /*-----------------------------------------------------------------*
113 * - find unity gain pitch excitation (adapitve codebook entry) *
114 * with fractional interpolation. *
115 * - find filtered pitch exc. y1[]=exc[] convolve with h1[]) *
116 * - compute pitch gain and limit between 0 and 1.2 *
117 * - update target vector for codebook search *
118 * - find LTP residual. *
119 *-----------------------------------------------------------------*/
120
121 Pred_lt_3or6(exc, *T0, *T0_frac, L_SUBFR, resu3);
122
123 Convolve(exc, h1, y1, L_SUBFR);
124
125 /* gain_pit is Q14 for all modes */
126 *gain_pit = G_pitch(mode, xn, y1, g_coeff, L_SUBFR); move16 ();
127
128
129 /* check if the pitch gain should be limit due to resonance in LPC filter */
130 gpc_flag = 0; move16 ();
131 *gp_limit = MAX_16; move16 ();
132 test (); test ();
133 if ((lsp_flag != 0) &&
134 (sub(*gain_pit, GP_CLIP) > 0))
135 {
136 gpc_flag = check_gp_clipping(tonSt, *gain_pit); move16 ();
137 }
138
139 /* special for the MR475, MR515 mode; limit the gain to 0.85 to */
140 /* cope with bit errors in the decoder in a better way. */
141 test (); test ();
142 if ((sub (mode, MR475) == 0) || (sub (mode, MR515) == 0)) {
143 test ();
144 if ( sub (*gain_pit, 13926) > 0) {
145 *gain_pit = 13926; /* 0.85 in Q14 */ move16 ();
146 }
147
148 test ();
149 if (gpc_flag != 0) {
150 *gp_limit = GP_CLIP; move16 ();
151 }
152 }
153 else
154 {
155 test ();
156 if (gpc_flag != 0)
157 {
158 *gp_limit = GP_CLIP; move16 ();
159 *gain_pit = GP_CLIP; move16 ();
160 }
161 /* For MR122, gain_pit is quantized here and not in gainQuant */
162 if (test (), sub(mode, MR122)==0)
163 {
164 *(*anap)++ = q_gain_pitch(MR122, *gp_limit, gain_pit,
165 NULL, NULL);
166 move16 ();
167 }
168 }
169
170 /* update target vector und evaluate LTP residual */
171 for (i = 0; i < L_SUBFR; i++) {
172 L_temp = L_mult(y1[i], *gain_pit);
173 L_temp = L_shl(L_temp, 1);
174 xn2[i] = sub(xn[i], extract_h(L_temp)); move16 ();
175
176 L_temp = L_mult(exc[i], *gain_pit);
177 L_temp = L_shl(L_temp, 1);
178 res2[i] = sub(res2[i], extract_h(L_temp)); move16 ();
179 }
180
181 return 0;
182 }