FreeCalypso > hg > gsm-codec-lib

annotate libgsmfrp/comfort_noise.c @ 64:1cc2968f883f

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
libgsmefr: dec_12k2.c compiles
author Mychaela Falconia <falcon@freecalypso.org>
date Sat, 26 Nov 2022 02:05:51 +0000
parents 286d5f097eb4
children 3b64f255689a
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
4
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1 /*
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
2 * In this module we implement comfort noise generation per GSM 06.12
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
3 * or 3GPP TS 46.012.
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
4 */
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
5
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
6 #include <stdint.h>
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
7 #include <string.h>
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
8 #include "gsm_fr_preproc.h"
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
9 #include "internal.h"
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
10
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
11 static const uint8_t fold_table_8to6[24] = {
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
12 1, 2, 3, 4, 5, 6, 1, 2,
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
13 1, 2, 3, 4, 5, 6, 3, 4,
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
14 1, 2, 3, 4, 5, 6, 5, 6,
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
15 };
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
16
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
17 static const uint8_t bc[4] = {0, 0, 0, 0};
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
18 static const uint8_t Nc[4] = {40, 120, 40, 120};
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
19
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
20 /* pseudonoise() function is based on ETSI EFR code */
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
21
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
22 static uint16_t pseudonoise(struct gsmfr_preproc_state *st, uint16_t no_bits)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
23 {
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
24 uint16_t noise_bits, Sn, i;
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
25
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
26 noise_bits = 0;
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
27 for (i = 0; i < no_bits; i++)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
28 {
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
29 /* State n == 31 */
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
30 if ((st->cn_random_lfsr & 0x00000001L) != 0)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
31 {
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
32 Sn = 1;
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
33 }
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
34 else
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
35 {
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
36 Sn = 0;
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
37 }
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
38
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
39 /* State n == 3 */
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
40 if ((st->cn_random_lfsr & 0x10000000L) != 0)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
41 {
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
42 Sn = Sn ^ 1;
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
43 }
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
44 else
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
45 {
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
46 Sn = Sn ^ 0;
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
47 }
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
48
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
49 noise_bits = noise_bits << 1;
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
50 noise_bits = noise_bits | st->cn_random_lfsr & 1;
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
51
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
52 st->cn_random_lfsr >>= 1;
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
53 if (Sn & 1)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
54 {
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
55 st->cn_random_lfsr |= 0x40000000L;
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
56 }
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
57 }
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
58
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
59 return noise_bits;
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
60 }
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
61
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
62 static uint8_t random_1to6(struct gsmfr_preproc_state *st)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
63 {
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
64 uint8_t range8, range6;
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
65
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
66 range8 = pseudonoise(st, 3);
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
67 range6 = fold_table_8to6[(st->cn_random_6fold << 3) | range8];
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
68 st->cn_random_6fold++;
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
69 if (st->cn_random_6fold >= 3)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
70 st->cn_random_6fold = 0;
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
71 return range6;
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
72 }
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
73
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
74 void gsmfr_preproc_gen_cn(struct gsmfr_preproc_state *st, gsm_byte *frame)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
75 {
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
76 unsigned sub, pulse;
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
77 uint8_t Mc, xmc[13];
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
78 gsm_byte *c;
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
79
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
80 /* global bytes (magic and LARc) are fixed */
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
81 memcpy(frame, st->sid_prefix, 5);
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
82 c = frame + 5;
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
83 /* now do the 4 subframes, mostly PRNG output */
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
84 for (sub = 0; sub < 4; sub++) {
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
85 Mc = pseudonoise(st, 2);
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
86 for (pulse = 0; pulse < 13; pulse++)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
87 xmc[pulse] = random_1to6(st);
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
88 /* packing code from libgsm */
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
89 *c++ = ((Nc[sub] & 0x7F) << 1)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
90 | ((bc[sub] >> 1) & 0x1);
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
91 *c++ = ((bc[sub] & 0x1) << 7)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
92 | ((Mc & 0x3) << 5)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
93 | ((st->sid_xmaxc[sub] >> 1) & 0x1F);
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
94 *c++ = ((st->sid_xmaxc[sub] & 0x1) << 7)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
95 | ((xmc[0] & 0x7) << 4)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
96 | ((xmc[1] & 0x7) << 1)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
97 | ((xmc[2] >> 2) & 0x1);
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
98 *c++ = ((xmc[2] & 0x3) << 6)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
99 | ((xmc[3] & 0x7) << 3)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
100 | (xmc[4] & 0x7);
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
101 *c++ = ((xmc[5] & 0x7) << 5)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
102 | ((xmc[6] & 0x7) << 2)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
103 | ((xmc[7] >> 1) & 0x3);
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
104 *c++ = ((xmc[7] & 0x1) << 7)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
105 | ((xmc[8] & 0x7) << 4)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
106 | ((xmc[9] & 0x7) << 1)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
107 | ((xmc[10] >> 2) & 0x1);
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
108 *c++ = ((xmc[10] & 0x3) << 6)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
109 | ((xmc[11] & 0x7) << 3)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
110 | (xmc[12] & 0x7);
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
111 }
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
112 }