FreeCalypso > hg > gsm-codec-lib

annotate libgsmfrp/comfort_noise.c @ 172:693a0958a303

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
yet another refactoring of RTP tools: the program that prints each time delta is now rtp-jitter-view, whereas rtp-cont-check now reports min and max instead.
author Mychaela Falconia <falcon@freecalypso.org>
date Mon, 26 Dec 2022 22:42:41 +0000
parents 3b64f255689a
children f081a6850fb5
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)
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
51 | ((st->sid_xmaxc[sub] >> 1) & 0x1F);
286d5f097eb4 libgsmfrp: implement comfort noise generation
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
52 *c++ = ((st->sid_xmaxc[sub] & 0x1) << 7)
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 }