FreeCalypso > hg > gsm-codec-lib

annotate libgsmfrp/comfort_noise.c @ 250:731c98b67da1

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
doc/FR1-Rx-DTX: document changes from 1.0.1 to 1.0.2
author Mychaela Falconia <falcon@freecalypso.org>
date Fri, 12 May 2023 04:49:09 +0000
parents f081a6850fb5
children
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 static uint8_t random_1to6(struct gsmfr_preproc_state *st)
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 uint8_t range8, range6;
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
23
108
3b64f255689a libgsmfrp: factor out PRNG into its own module,
Mychaela Falconia <falcon@freecalypso.org>
parents: 4
diff changeset
24 range8 = gsmfr_preproc_prng(st, 3);
4
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
25 range6 = fold_table_8to6[(st->cn_random_6fold << 3) | range8];
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
26 st->cn_random_6fold++;
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
27 if (st->cn_random_6fold >= 3)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
28 st->cn_random_6fold = 0;
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
29 return range6;
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
30 }
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 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
33 {
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
34 unsigned sub, pulse;
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
35 uint8_t Mc, xmc[13];
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
36 gsm_byte *c;
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 /* global bytes (magic and LARc) are fixed */
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
39 memcpy(frame, st->sid_prefix, 5);
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
40 c = frame + 5;
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
41 /* now do the 4 subframes, mostly PRNG output */
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
42 for (sub = 0; sub < 4; sub++) {
108
3b64f255689a libgsmfrp: factor out PRNG into its own module,
Mychaela Falconia <falcon@freecalypso.org>
parents: 4
diff changeset
43 Mc = gsmfr_preproc_prng(st, 2);
4
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
44 for (pulse = 0; pulse < 13; pulse++)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
45 xmc[pulse] = random_1to6(st);
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
46 /* packing code from libgsm */
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
47 *c++ = ((Nc[sub] & 0x7F) << 1)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
48 | ((bc[sub] >> 1) & 0x1);
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
49 *c++ = ((bc[sub] & 0x1) << 7)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
50 | ((Mc & 0x3) << 5)
242
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
51 | ((st->sid_xmaxc >> 1) & 0x1F);
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
52 *c++ = ((st->sid_xmaxc & 0x1) << 7)
4
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
53 | ((xmc[0] & 0x7) << 4)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
54 | ((xmc[1] & 0x7) << 1)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
55 | ((xmc[2] >> 2) & 0x1);
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
56 *c++ = ((xmc[2] & 0x3) << 6)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
57 | ((xmc[3] & 0x7) << 3)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
58 | (xmc[4] & 0x7);
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
59 *c++ = ((xmc[5] & 0x7) << 5)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
60 | ((xmc[6] & 0x7) << 2)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
61 | ((xmc[7] >> 1) & 0x3);
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
62 *c++ = ((xmc[7] & 0x1) << 7)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
63 | ((xmc[8] & 0x7) << 4)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
64 | ((xmc[9] & 0x7) << 1)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
65 | ((xmc[10] >> 2) & 0x1);
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
66 *c++ = ((xmc[10] & 0x3) << 6)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
67 | ((xmc[11] & 0x7) << 3)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
68 | (xmc[12] & 0x7);
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
69 }
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
70 }
242
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
71
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
72 void gsmfr_preproc_sid2cn(struct gsmfr_preproc_state *st, gsm_byte *frame)
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
73 {
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
74 unsigned sub, pulse;
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
75 uint8_t Mc, xmc[13];
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
76 gsm_byte *c;
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
77
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
78 /* save LARc and Xmaxc from the last subframe for subsequent CN gen */
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
79 memcpy(st->sid_prefix, frame, 5);
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
80 st->sid_xmaxc = ((frame[27] & 0x1F) << 1) | (frame[28] >> 7);
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
81 /* ... and turn *this* frame into very first CN output */
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
82 c = frame + 5;
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
83 for (sub = 0; sub < 4; sub++) {
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
84 Mc = gsmfr_preproc_prng(st, 2);
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
85 for (pulse = 0; pulse < 13; pulse++)
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
86 xmc[pulse] = random_1to6(st);
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
87 /* keep each of Xmaxc and replace the rest with CN */
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
88 *c++ = ((Nc[sub] & 0x7F) << 1)
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
89 | ((bc[sub] >> 1) & 0x1);
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
90 *c &= 0x1F;
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
91 *c++ |= ((bc[sub] & 0x1) << 7)
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
92 | ((Mc & 0x3) << 5);
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
93 *c &= 0x80;
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
94 *c++ |= ((xmc[0] & 0x7) << 4)
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
95 | ((xmc[1] & 0x7) << 1)
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
96 | ((xmc[2] >> 2) & 0x1);
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
97 *c++ = ((xmc[2] & 0x3) << 6)
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
98 | ((xmc[3] & 0x7) << 3)
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
99 | (xmc[4] & 0x7);
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
100 *c++ = ((xmc[5] & 0x7) << 5)
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
101 | ((xmc[6] & 0x7) << 2)
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
102 | ((xmc[7] >> 1) & 0x3);
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
103 *c++ = ((xmc[7] & 0x1) << 7)
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
104 | ((xmc[8] & 0x7) << 4)
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
105 | ((xmc[9] & 0x7) << 1)
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
106 | ((xmc[10] >> 2) & 0x1);
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
107 *c++ = ((xmc[10] & 0x3) << 6)
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
108 | ((xmc[11] & 0x7) << 3)
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
109 | (xmc[12] & 0x7);
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
110 }
f081a6850fb5 libgsmfrp: new refined implementation
Mychaela Falconia <falcon@freecalypso.org>
parents: 108
diff changeset
111 }