FreeCalypso > hg > gsm-codec-lib

comparison libtwamr/q_gain_c.c @ 368:3a25bdfad0d8

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
libtwamr: integrate q_gain_c.c
author Mychaela Falconia <falcon@freecalypso.org>
date Mon, 06 May 2024 03:18:47 +0000
parents
children
comparison
equal deleted inserted replaced
367:bd4f660eb75a 368:3a25bdfad0d8
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 : q_gain_c.c
11 * Purpose : Scalar quantization of the innovative
12 * : codebook gain.
13 *
14 ********************************************************************************
15 */
16
17 /*
18 ********************************************************************************
19 * MODULE INCLUDE FILE AND VERSION ID
20 ********************************************************************************
21 */
22 #include "namespace.h"
23 #include "q_gain_c.h"
24
25 /*
26 ********************************************************************************
27 * INCLUDE FILES
28 ********************************************************************************
29 */
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 "log2.h"
36 #include "pow2.h"
37 #include "gains_tab.h"
38
39 /*
40 ********************************************************************************
41 * PUBLIC PROGRAM CODE
42 ********************************************************************************
43 */
44
45 /*--------------------------------------------------------------------------*
46 * Function q_gain_code() *
47 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ *
48 * Scalar quantization of the innovative codebook gain. *
49 * *
50 *--------------------------------------------------------------------------*/
51 Word16 q_gain_code ( /* o : quantization index, Q0 */
52 enum Mode mode, /* i : AMR mode */
53 Word16 exp_gcode0, /* i : predicted CB gain (exponent), Q0 */
54 Word16 frac_gcode0, /* i : predicted CB gain (fraction), Q15 */
55 Word16 *gain, /* i/o: quantized fixed codebook gain, Q1 */
56 Word16 *qua_ener_MR122, /* o : quantized energy error, Q10 */
57 /* (for MR122 MA predictor update) */
58 Word16 *qua_ener /* o : quantized energy error, Q10 */
59 /* (for other MA predictor update) */
60 )
61 {
62 const Word16 *p;
63 Word16 i, index;
64 Word16 gcode0, err, err_min;
65 Word16 g_q0;
66
67 test ();
68 g_q0 = 0; move16 ();
69 test ();
70 if (sub(mode, MR122) == 0)
71 {
72 g_q0 = shr (*gain, 1); /* Q1 -> Q0 */
73 }
74
75 /*-------------------------------------------------------------------*
76 * predicted codebook gain *
77 * ~~~~~~~~~~~~~~~~~~~~~~~ *
78 * gc0 = Pow2(int(d)+frac(d)) *
79 * = 2^exp + 2^frac *
80 * *
81 *-------------------------------------------------------------------*/
82
83 gcode0 = extract_l (Pow2 (exp_gcode0, frac_gcode0)); /* predicted gain */
84
85 test ();
86 if (sub(mode, MR122) == 0)
87 {
88 gcode0 = shl (gcode0, 4);
89 }
90 else
91 {
92 gcode0 = shl (gcode0, 5);
93 }
94
95 /*-------------------------------------------------------------------*
96 * Search for best quantizer *
97 *-------------------------------------------------------------------*/
98
99 p = &qua_gain_code[0]; move16 ();
100 test ();
101 if (sub(mode, MR122) == 0)
102 {
103 err_min = abs_s (sub (g_q0, mult (gcode0, *p++)));
104 }
105 else
106 {
107 err_min = abs_s (sub (*gain, mult (gcode0, *p++)));
108 }
109 p += 2; /* skip quantized energy errors */
110 index = 0; move16 ();
111
112 for (i = 1; i < NB_QUA_CODE; i++)
113 {
114 test ();
115 if (sub(mode, MR122) == 0)
116 {
117 err = abs_s (sub (g_q0, mult (gcode0, *p++)));
118 }
119 else
120 {
121 err = abs_s (sub (*gain, mult (gcode0, *p++)));
122 }
123
124 p += 2; /* skip quantized energy error */
125
126 test ();
127 if (sub (err, err_min) < 0)
128 {
129 err_min = err; move16 ();
130 index = i; move16 ();
131 }
132 }
133
134 p = &qua_gain_code[add (add (index,index), index)]; move16 ();
135 test ();
136 if (sub(mode, MR122) == 0)
137 {
138 *gain = shl (mult (gcode0, *p++), 1);
139 }
140 else
141 {
142 *gain = mult (gcode0, *p++);
143 }
144 move16 ();
145
146 /* quantized error energies (for MA predictor update) */
147 *qua_ener_MR122 = *p++; move16 ();
148 *qua_ener = *p; move16 ();
149
150 return index;
151 }