annotate dev/s2u-regen-plus4.c @ 403:7e0aeab69b10

libtwamr: integrate spreproc.c
author Mychaela Falconia <falcon@freecalypso.org>
date Mon, 06 May 2024 23:11:34 +0000
parents 67d60915fbbe
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
222
842136bbd0da dev: new program s2a-regen
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1 /*
228
67d60915fbbe dev: new program s2u-regen-plus4
Mychaela Falconia <falcon@freecalypso.org>
parents: 227
diff changeset
2 * This program is a companion to s2u-regen.c: it computes a mu-law encoding
67d60915fbbe dev: new program s2u-regen-plus4
Mychaela Falconia <falcon@freecalypso.org>
parents: 227
diff changeset
3 * table with 13-bit input just like s2u-regen, but computes it as if the
67d60915fbbe dev: new program s2u-regen-plus4
Mychaela Falconia <falcon@freecalypso.org>
parents: 227
diff changeset
4 * lsb following the 13-bit part is always 1 rather than always 0. The
67d60915fbbe dev: new program s2u-regen-plus4
Mychaela Falconia <falcon@freecalypso.org>
parents: 227
diff changeset
5 * purpose of this program is to illustrate the effect of that lsb on the
67d60915fbbe dev: new program s2u-regen-plus4
Mychaela Falconia <falcon@freecalypso.org>
parents: 227
diff changeset
6 * mu-law output.
222
842136bbd0da dev: new program s2a-regen
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
7 */
842136bbd0da dev: new program s2a-regen
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
8
842136bbd0da dev: new program s2a-regen
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
9 #include <stdio.h>
842136bbd0da dev: new program s2a-regen
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
10 #include <stdlib.h>
842136bbd0da dev: new program s2a-regen
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
11
842136bbd0da dev: new program s2a-regen
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
12 static unsigned
226
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
13 ulaw_compress(input)
222
842136bbd0da dev: new program s2a-regen
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
14 unsigned input;
842136bbd0da dev: new program s2a-regen
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
15 {
226
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
16 short i; /* aux.var. */
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
17 short absno; /* absolute value of linear (input) sample */
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
18 short segno; /* segment (Table 2/G711, column 1) */
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
19 short low_nibble; /* low nibble of log companded sample */
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
20 short high_nibble; /* high nibble of log companded sample */
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
21 unsigned output;
222
842136bbd0da dev: new program s2a-regen
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
22
226
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
23 /* -------------------------------------------------------------------- */
227
a5200ad12d58 dev/s2u-regen.c: new approach
Mychaela Falconia <falcon@freecalypso.org>
parents: 226
diff changeset
24 /* Input is 14-bit right-justified in this version */
226
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
25 /* Compute absolute value; adjust for easy processing */
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
26 /* -------------------------------------------------------------------- */
227
a5200ad12d58 dev/s2u-regen.c: new approach
Mychaela Falconia <falcon@freecalypso.org>
parents: 226
diff changeset
27 absno = input >= 0x2000 /* compute 1's complement in case of */
a5200ad12d58 dev/s2u-regen.c: new approach
Mychaela Falconia <falcon@freecalypso.org>
parents: 226
diff changeset
28 ? (~input & 0x1FFF) + 33 /* negative samples */
a5200ad12d58 dev/s2u-regen.c: new approach
Mychaela Falconia <falcon@freecalypso.org>
parents: 226
diff changeset
29 : input + 33; /* NB: 33 is the difference value */
226
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
30 /* between the thresholds for */
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
31 /* A-law and u-law. */
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
32 if (absno > (0x1FFF)) /* limitation to "absno" < 8192 */
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
33 absno = (0x1FFF);
222
842136bbd0da dev: new program s2a-regen
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
34
226
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
35 /* Determination of sample's segment */
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
36 i = absno >> 6;
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
37 segno = 1;
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
38 while (i != 0) {
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
39 segno++;
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
40 i >>= 1;
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
41 }
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
42
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
43 /* Mounting the high-nibble of the log-PCM sample */
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
44 high_nibble = (0x0008) - segno;
222
842136bbd0da dev: new program s2a-regen
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
45
226
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
46 /* Mounting the low-nibble of the log PCM sample */
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
47 low_nibble = (absno >> segno) /* right shift of mantissa and */
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
48 &(0x000F); /* masking away leading '1' */
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
49 low_nibble = (0x000F) - low_nibble;
222
842136bbd0da dev: new program s2a-regen
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
50
226
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
51 /* Joining the high-nibble and the low-nibble of the log PCM sample */
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
52 output = (high_nibble << 4) | low_nibble;
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
53
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
54 /* Add sign bit */
227
a5200ad12d58 dev/s2u-regen.c: new approach
Mychaela Falconia <falcon@freecalypso.org>
parents: 226
diff changeset
55 if (input < 0x2000)
226
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
56 output = output | (0x0080);
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
57
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
58 return output;
222
842136bbd0da dev: new program s2a-regen
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
59 }
842136bbd0da dev: new program s2a-regen
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
60
842136bbd0da dev: new program s2a-regen
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
61 main(argc, argv)
842136bbd0da dev: new program s2a-regen
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
62 char **argv;
842136bbd0da dev: new program s2a-regen
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
63 {
842136bbd0da dev: new program s2a-regen
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
64 unsigned input, output;
842136bbd0da dev: new program s2a-regen
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
65
226
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
66 for (input = 0; input < 8192; input++) {
228
67d60915fbbe dev: new program s2u-regen-plus4
Mychaela Falconia <falcon@freecalypso.org>
parents: 227
diff changeset
67 output = ulaw_compress((input << 1) + 1);
226
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
68 printf("%04o,", output);
84d22eb72196 dev: new program s2u-regen
Mychaela Falconia <falcon@freecalypso.org>
parents: 223
diff changeset
69 if ((input % 15) == 14 || input == 8191)
222
842136bbd0da dev: new program s2a-regen
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
70 putchar('\n');
842136bbd0da dev: new program s2a-regen
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
71 }
842136bbd0da dev: new program s2a-regen
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
72 exit(0);
842136bbd0da dev: new program s2a-regen
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
73 }