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