1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
|
/*
* encode.c
*
* CCITT ADPCM encoder
*
* Usage : encode [-3|4|5] [-a|u|l] < infile > outfile
*/
#include <stdio.h>
#include "g72x.h"
/*
* Pack output codes into bytes and write them to stdout.
* Returns 1 if there is residual output, else returns 0.
*/
int
pack_output(
unsigned code,
int bits)
{
static unsigned int out_buffer = 0;
static int out_bits = 0;
unsigned char out_byte;
out_buffer |= (code << out_bits);
out_bits += bits;
if (out_bits >= 8) {
out_byte = out_buffer & 0xff;
out_bits -= 8;
out_buffer >>= 8;
fwrite(&out_byte, sizeof (char), 1, stdout);
}
return (out_bits > 0);
}
main(
int argc,
char **argv)
{
struct g72x_state state;
unsigned char sample_char;
short sample_short;
unsigned char code;
int resid;
int in_coding;
int in_size;
unsigned *in_buf;
int (*enc_routine)();
int enc_bits;
g72x_init_state(&state);
/* Set defaults to u-law input, G.721 output */
in_coding = AUDIO_ENCODING_ULAW;
in_size = sizeof (char);
in_buf = (unsigned *)&sample_char;
enc_routine = g721_encoder;
enc_bits = 4;
/* Process encoding argument, if any */
while ((argc > 1) && (argv[1][0] == '-')) {
switch (argv[1][1]) {
case '3':
enc_routine = g723_24_encoder;
enc_bits = 3;
break;
case '4':
enc_routine = g721_encoder;
enc_bits = 4;
break;
case '5':
enc_routine = g723_40_encoder;
enc_bits = 5;
break;
case 'u':
in_coding = AUDIO_ENCODING_ULAW;
in_size = sizeof (char);
in_buf = (unsigned *)&sample_char;
break;
case 'a':
in_coding = AUDIO_ENCODING_ALAW;
in_size = sizeof (char);
in_buf = (unsigned *)&sample_char;
break;
case 'l':
in_coding = AUDIO_ENCODING_LINEAR;
in_size = sizeof (short);
in_buf = (unsigned *)&sample_short;
break;
default:
fprintf(stderr, "CCITT ADPCM Encoder -- usage:\n");
fprintf(stderr, "\tencode [-3|4|5] [-a|u|l] < infile > outfile\n");
fprintf(stderr, "where:\n");
fprintf(stderr, "\t-3\tGenerate G.723 24kbps (3-bit) data\n");
fprintf(stderr, "\t-4\tGenerate G.721 32kbps (4-bit) data [default]\n");
fprintf(stderr, "\t-5\tGenerate G.723 40kbps (5-bit) data\n");
fprintf(stderr, "\t-a\tProcess 8-bit A-law input data\n");
fprintf(stderr, "\t-u\tProcess 8-bit u-law input data [default]\n");
fprintf(stderr, "\t-l\tProcess 16-bit linear PCM input data\n");
exit(1);
}
argc--;
argv++;
}
/* Read input file and process */
while (fread(in_buf, in_size, 1, stdin) == 1) {
code = (*enc_routine)(in_size == 2 ? sample_short : sample_char,
in_coding, &state);
resid = pack_output(code, enc_bits);
}
/* Write zero codes until all residual codes are written out */
while (resid) {
resid = pack_output(0, enc_bits);
}
fclose(stdout);
}
|
