FreeCalypso > hg > efr-experiments

annotate src/agc.c @ 6:6119d2c1e7d9

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
EFR2 encoder: mimic 5 ms delay of AMR
author Mychaela Falconia <falcon@freecalypso.org>
date Wed, 03 Apr 2024 07:14:01 +0000
parents 56410792419a
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
0
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1 /*************************************************************************
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
2 *
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
3 * FUNCTION: agc
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
4 *
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
5 * PURPOSE: Scales the postfilter output on a subframe basis by automatic
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
6 * control of the subframe gain.
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
7 *
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
8 * DESCRIPTION:
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
9 * sig_out[n] = sig_out[n] * gain[n];
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
10 * where gain[n] is the gain at the nth sample given by
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
11 * gain[n] = agc_fac * gain[n-1] + (1 - agc_fac) g_in/g_out
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
12 * g_in/g_out is the square root of the ratio of energy at the input
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
13 * and output of the postfilter.
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
14 *
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
15 *************************************************************************/
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
16
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
17 #include "typedef.h"
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
18 #include "basic_op.h"
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
19 #include "count.h"
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
20 #include "sig_proc.h"
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
21 #include "cnst.h"
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
22
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
23 Word16 past_gain; /* initial value of past_gain = 1.0 */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
24
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
25 void agc (
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
26 Word16 *sig_in, /* (i) : postfilter input signal */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
27 Word16 *sig_out, /* (i/o) : postfilter output signal */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
28 Word16 agc_fac, /* (i) : AGC factor */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
29 Word16 l_trm /* (i) : subframe size */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
30 )
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
31 {
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
32 Word16 i, exp;
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
33 Word16 gain_in, gain_out, g0, gain;
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
34 Word32 s;
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
35
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
36 Word16 temp;
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
37
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
38 /* calculate gain_out with exponent */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
39
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
40 temp = shr (sig_out[0], 2);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
41 s = L_mult (temp, temp);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
42
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
43 for (i = 1; i < l_trm; i++)
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
44 {
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
45 temp = shr (sig_out[i], 2);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
46 s = L_mac (s, temp, temp);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
47 }
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
48
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
49 test ();
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
50 if (s == 0)
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
51 {
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
52 past_gain = 0; move16 ();
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
53 return;
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
54 }
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
55 exp = sub (norm_l (s), 1);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
56 gain_out = round (L_shl (s, exp));
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
57
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
58 /* calculate gain_in with exponent */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
59
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
60 temp = shr (sig_in[0], 2);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
61 s = L_mult (temp, temp);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
62
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
63 for (i = 1; i < l_trm; i++)
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
64 {
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
65 temp = shr (sig_in[i], 2);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
66 s = L_mac (s, temp, temp);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
67 }
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
68
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
69 test ();
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
70 if (s == 0)
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
71 {
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
72 g0 = 0; move16 ();
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
73 }
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
74 else
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
75 {
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
76 i = norm_l (s);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
77 gain_in = round (L_shl (s, i));
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
78 exp = sub (exp, i);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
79
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
80 /*---------------------------------------------------*
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
81 * g0 = (1-agc_fac) * sqrt(gain_in/gain_out); *
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
82 *---------------------------------------------------*/
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
83
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
84 s = L_deposit_l (div_s (gain_out, gain_in));
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
85 s = L_shl (s, 7); /* s = gain_out / gain_in */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
86 s = L_shr (s, exp); /* add exponent */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
87
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
88 s = Inv_sqrt (s);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
89 i = round (L_shl (s, 9));
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
90
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
91 /* g0 = i * (1-agc_fac) */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
92 g0 = mult (i, sub (32767, agc_fac));
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
93 }
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
94
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
95 /* compute gain[n] = agc_fac * gain[n-1]
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
96 + (1-agc_fac) * sqrt(gain_in/gain_out) */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
97 /* sig_out[n] = gain[n] * sig_out[n] */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
98
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
99 gain = past_gain; move16 ();
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
100
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
101 for (i = 0; i < l_trm; i++)
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
102 {
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
103 gain = mult (gain, agc_fac);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
104 gain = add (gain, g0);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
105 sig_out[i] = extract_h (L_shl (L_mult (sig_out[i], gain), 3));
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
106 move16 ();
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
107 }
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
108
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
109 past_gain = gain; move16 ();
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
110
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
111 return;
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
112 }
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
113
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
114 void agc2 (
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
115 Word16 *sig_in, /* (i) : postfilter input signal */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
116 Word16 *sig_out, /* (i/o) : postfilter output signal */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
117 Word16 l_trm /* (i) : subframe size */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
118 )
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
119 {
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
120 Word16 i, exp;
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
121 Word16 gain_in, gain_out, g0;
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
122 Word32 s;
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
123
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
124 Word16 temp;
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
125
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
126 /* calculate gain_out with exponent */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
127
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
128 temp = shr (sig_out[0], 2);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
129 s = L_mult (temp, temp);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
130 for (i = 1; i < l_trm; i++)
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
131 {
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
132 temp = shr (sig_out[i], 2);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
133 s = L_mac (s, temp, temp);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
134 }
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
135
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
136 test ();
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
137 if (s == 0)
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
138 {
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
139 return;
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
140 }
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
141 exp = sub (norm_l (s), 1);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
142 gain_out = round (L_shl (s, exp));
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
143
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
144 /* calculate gain_in with exponent */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
145
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
146 temp = shr (sig_in[0], 2);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
147 s = L_mult (temp, temp);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
148 for (i = 1; i < l_trm; i++)
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
149 {
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
150 temp = shr (sig_in[i], 2);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
151 s = L_mac (s, temp, temp);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
152 }
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
153
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
154 test ();
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
155 if (s == 0)
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
156 {
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
157 g0 = 0; move16 ();
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
158 }
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
159 else
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
160 {
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
161 i = norm_l (s);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
162 gain_in = round (L_shl (s, i));
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
163 exp = sub (exp, i);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
164
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
165 /*---------------------------------------------------*
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
166 * g0 = sqrt(gain_in/gain_out); *
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
167 *---------------------------------------------------*/
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
168
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
169 s = L_deposit_l (div_s (gain_out, gain_in));
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
170 s = L_shl (s, 7); /* s = gain_out / gain_in */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
171 s = L_shr (s, exp); /* add exponent */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
172
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
173 s = Inv_sqrt (s);
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
174 g0 = round (L_shl (s, 9));
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
175 }
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
176
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
177 /* sig_out(n) = gain(n) sig_out(n) */
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
178
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
179 for (i = 0; i < l_trm; i++)
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
180 {
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
181 sig_out[i] = extract_h (L_shl (L_mult (sig_out[i], g0), 3));
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
182 move16 ();
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
183 }
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
184
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
185 return;
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
186 }