FreeCalypso > hg > gsm-codec-lib
comparison libtwamr/dec_gain.c @ 356:5ccfe176bae1
libtwamr: integrate dec_gain.c
author | Mychaela Falconia <falcon@freecalypso.org> |
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date | Sun, 05 May 2024 22:24:42 +0000 |
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355:9beb01439a90 | 356:5ccfe176bae1 |
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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 : dec_gain.c | |
11 * Purpose : Decode the pitch and codebook gains | |
12 * | |
13 ******************************************************************************** | |
14 */ | |
15 | |
16 /* | |
17 ******************************************************************************** | |
18 * MODULE INCLUDE FILE AND VERSION ID | |
19 ******************************************************************************** | |
20 */ | |
21 #include "namespace.h" | |
22 #include "dec_gain.h" | |
23 | |
24 /* | |
25 ******************************************************************************** | |
26 * INCLUDE FILES | |
27 ******************************************************************************** | |
28 */ | |
29 #include <stddef.h> | |
30 #include "tw_amr.h" | |
31 #include "typedef.h" | |
32 #include "basic_op.h" | |
33 #include "oper_32b.h" | |
34 #include "no_count.h" | |
35 #include "cnst.h" | |
36 #include "pow2.h" | |
37 #include "log2.h" | |
38 #include "gc_pred.h" | |
39 #include "qua_gain_tab.h" | |
40 | |
41 /* | |
42 ******************************************************************************** | |
43 * PUBLIC PROGRAM CODE | |
44 ******************************************************************************** | |
45 */ | |
46 | |
47 /************************************************************************* | |
48 * | |
49 * FUNCTION: Dec_gain() | |
50 * | |
51 * PURPOSE: Decode the pitch and codebook gains | |
52 * | |
53 ************************************************************************/ | |
54 void Dec_gain( | |
55 gc_predState *pred_state, /* i/o: MA predictor state */ | |
56 enum Mode mode, /* i : AMR mode */ | |
57 Word16 index, /* i : index of quantization. */ | |
58 Word16 code[], /* i : Innovative vector. */ | |
59 Word16 evenSubfr, /* i : Flag for even subframes */ | |
60 Word16 * gain_pit, /* o : Pitch gain. */ | |
61 Word16 * gain_cod /* o : Code gain. */ | |
62 ) | |
63 { | |
64 const Word16 *p; | |
65 Word16 frac, gcode0, exp, qua_ener, qua_ener_MR122; | |
66 Word16 g_code; | |
67 Word32 L_tmp; | |
68 | |
69 /* Read the quantized gains (table depends on mode) */ | |
70 index = shl (index, 2); | |
71 | |
72 test(); test(); test(); | |
73 if ( sub (mode, MR102) == 0 | |
74 || sub (mode, MR74) == 0 | |
75 || sub (mode, MR67) == 0) | |
76 { | |
77 p = &table_gain_highrates[index]; move16 (); | |
78 | |
79 *gain_pit = *p++; move16 (); | |
80 g_code = *p++; move16 (); | |
81 qua_ener_MR122 = *p++; move16 (); | |
82 qua_ener = *p; move16 (); | |
83 } | |
84 else | |
85 { | |
86 test(); | |
87 if (sub (mode, MR475) == 0) | |
88 { | |
89 index = add (index, shl(sub(1, evenSubfr), 1)); | |
90 p = &table_gain_MR475[index]; move16 (); | |
91 | |
92 *gain_pit = *p++; move16 (); | |
93 g_code = *p++; move16 (); | |
94 | |
95 /*---------------------------------------------------------* | |
96 * calculate predictor update values (not stored in 4.75 * | |
97 * quantizer table to save space): * | |
98 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * | |
99 * * | |
100 * qua_ener = log2(g) * | |
101 * qua_ener_MR122 = 20*log10(g) * | |
102 *---------------------------------------------------------*/ | |
103 | |
104 /* Log2(x Q12) = log2(x) + 12 */ | |
105 Log2 (L_deposit_l (g_code), &exp, &frac); | |
106 exp = sub(exp, 12); | |
107 | |
108 qua_ener_MR122 = add (shr_r (frac, 5), shl (exp, 10)); | |
109 | |
110 /* 24660 Q12 ~= 6.0206 = 20*log10(2) */ | |
111 L_tmp = Mpy_32_16(exp, frac, 24660); | |
112 qua_ener = round (L_shl (L_tmp, 13)); /* Q12 * Q0 = Q13 -> Q10 */ | |
113 } | |
114 else | |
115 { | |
116 p = &table_gain_lowrates[index]; move16 (); | |
117 | |
118 *gain_pit = *p++; move16 (); | |
119 g_code = *p++; move16 (); | |
120 qua_ener_MR122 = *p++; move16 (); | |
121 qua_ener = *p; move16 (); | |
122 } | |
123 } | |
124 | |
125 /*-------------------------------------------------------------------* | |
126 * predict codebook gain * | |
127 * ~~~~~~~~~~~~~~~~~~~~~ * | |
128 * gc0 = Pow2(int(d)+frac(d)) * | |
129 * = 2^exp + 2^frac * | |
130 * * | |
131 * gcode0 (Q14) = 2^14*2^frac = gc0 * 2^(14-exp) * | |
132 *-------------------------------------------------------------------*/ | |
133 | |
134 gc_pred(pred_state, mode, code, &exp, &frac, NULL, NULL); | |
135 | |
136 gcode0 = extract_l(Pow2(14, frac)); | |
137 | |
138 /*------------------------------------------------------------------* | |
139 * read quantized gains, update table of past quantized energies * | |
140 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * | |
141 * st->past_qua_en(Q10) = 20 * Log10(g_fac) / constant * | |
142 * = Log2(g_fac) * | |
143 * = qua_ener * | |
144 * constant = 20*Log10(2) * | |
145 *------------------------------------------------------------------*/ | |
146 | |
147 L_tmp = L_mult(g_code, gcode0); | |
148 L_tmp = L_shr(L_tmp, sub(10, exp)); | |
149 *gain_cod = extract_h(L_tmp); | |
150 | |
151 /* update table of past quantized energies */ | |
152 | |
153 gc_pred_update(pred_state, qua_ener_MR122, qua_ener); | |
154 | |
155 return; | |
156 } |