FreeCalypso > hg > gsm-codec-lib

comparison dev/efr-sid-insert.c @ 35:3b5958f28a40

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
dev: efr-sid-insert helper program
author Mychaela Falconia <falcon@freecalypso.org>
date Thu, 24 Nov 2022 02:35:02 +0000
parents
children
comparison
equal deleted inserted replaced
34:69b9cbca075b 35:3b5958f28a40
1 /*
2 * We need to implement a function that inserts the 95 bit wide SID
3 * codeword into the frame, and we would like to do it more efficiently
4 * than calling a "set bit" function for each of the 95 bits. This
5 * program will produce a more efficient solution.
6 */
7
8 #include <stdio.h>
9 #include <stdint.h>
10 #include <stdlib.h>
11 #include <string.h>
12
13 static const uint8_t SID_codeword_bit_idx[95] =
14 {
15 45, 46, 48, 49, 50, 51, 52, 53, 54, 55,
16 56, 57, 58, 59, 60, 61, 62, 63, 64, 65,
17 66, 67, 68, 94, 95, 96, 98, 99, 100, 101,
18 102, 103, 104, 105, 106, 107, 108, 109, 110, 111,
19 112, 113, 114, 115, 116, 117, 118, 148, 149, 150,
20 151, 152, 153, 154, 155, 156, 157, 158, 159, 160,
21 161, 162, 163, 164, 165, 166, 167, 168, 169, 170,
22 171, 196, 197, 198, 199, 200, 201, 202, 203, 204,
23 205, 206, 207, 208, 209, 212, 213, 214, 215, 216,
24 217, 218, 219, 220, 221
25 };
26
27 static void set_bit(uint8_t *frame, unsigned bitnum)
28 {
29 unsigned bytenum = bitnum >> 3;
30 unsigned bit_in_byte = 7 - (bitnum & 7);
31 unsigned bitmask = 1 << bit_in_byte;
32
33 frame[bytenum] |= bitmask;
34 }
35
36 main(argc, argv)
37 char **argv;
38 {
39 uint8_t bytes[31];
40 unsigned n;
41
42 memset(bytes, 0, 31);
43 for (n = 0; n < 95; n++)
44 set_bit(bytes, SID_codeword_bit_idx[n] + 4);
45 for (n = 0; n < 31; n++)
46 if (bytes[n])
47 printf("\tframe[%u] |= 0x%02X;\n", n, bytes[n]);
48 exit(0);
49 }