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
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
|
/*
* id3v2 routines
*
* (c) 2005 bl0rg.net
*/
#include "conf.h"
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "file.h"
#include "pack.h"
#include "id3.h"
/* create a sync safe integer (bit 7 is 0) */
static unsigned long id3_sync_safe(unsigned long num) {
unsigned long res = 0;
int i;
for (i = 0; i < 4; i++) {
res |= (num & 0x7F) << (i * 8);
num >>= 7;
}
return res;
}
unsigned int id3_fill_comment(unsigned char *buf, unsigned int len,
unsigned char encoding,
unsigned char *short_comment,
unsigned char *long_comment,
unsigned char *language) {
assert(buf != NULL);
assert(len > 0);
if ((short_comment == NULL) &&
(long_comment == NULL))
return 0;
if (language == NULL)
language = "eng";
unsigned int short_len = short_comment ? strlen(short_comment) : 0;
unsigned int long_len = long_comment ? strlen(long_comment) : 0;
unsigned char *ptr = buf;
unsigned int flen = 1 + 3 + short_len + 1 + long_len + 1;
if (len < 6 + flen)
return 0;
memcpy(ptr, "COM", 3); ptr += 3;
UINT24_PACK(ptr, id3_sync_safe(flen));
UINT8_PACK(ptr, encoding);
memcpy(ptr, language, 3); ptr += 3;
if (short_comment) {
memcpy(ptr, short_comment, short_len);
ptr += short_len;
}
UINT8_PACK(ptr, 0x00);
if (long_comment) {
memcpy(ptr, long_comment, long_len);
ptr += long_len;
}
UINT8_PACK(ptr, 0x00);
return 6 + flen;
}
unsigned int id3_fill_tframe(unsigned char *buf, unsigned int len,
unsigned char *type,
unsigned char encoding,
unsigned char *string) {
assert(buf != NULL);
assert(len > 0);
assert(type != NULL);
assert(string != NULL);
unsigned char *ptr = buf;
unsigned int slen = strlen(string);
unsigned int flen = slen + 2;
if (len < 6 + flen)
return 0;
memcpy(ptr, type, 3); ptr += 3;
UINT24_PACK(ptr, id3_sync_safe(flen));
UINT8_PACK(ptr, encoding);
memcpy(ptr, string, slen); ptr += slen;
UINT8_PACK(ptr, 0x00);
return flen + 6;
}
int id3_fill_header(unsigned char *buf, unsigned int len,
unsigned long id3_size) {
assert(buf != NULL);
assert(len > 0);
if (len < 10)
return 0;
unsigned char *ptr = buf;
memcpy(ptr, "ID3", 3); ptr += 3;
UINT8_PACK(ptr, 0x02); UINT8_PACK(ptr, 0x00); /* version 2.0 */
UINT8_PACK(ptr, 0x00);
UINT32_PACK(ptr, id3_sync_safe(id3_size));
return 10;
}
int id3_write_tag(file_t *outfile,
unsigned char *album_title,
unsigned char *artist,
unsigned char *title,
unsigned int track_number,
unsigned char *comment) {
/* write id3 tags */
unsigned char id3[ID3_TAG_SIZE];
unsigned char *ptr = id3 + ID3_HEADER_SIZE;
unsigned int size = 0, bytes_left = sizeof(id3) - ID3_HEADER_SIZE;
unsigned int len;
if (album_title && strlen(album_title) > 0) {
len = id3_fill_tframe(ptr, bytes_left, "TAL", 0, album_title);
if (len == 0)
return 0;
bytes_left -= len; ptr += len; size += len;
}
if (artist && strlen(artist) > 0) {
len = id3_fill_tframe(ptr, bytes_left, "TP1", 0, artist);
if (len == 0)
return 0;
bytes_left -= len; ptr += len; size += len;
}
if (title && strlen(title) > 0) {
len = id3_fill_tframe(ptr, bytes_left, "TT2", 0, title);
if (len == 0)
return 0;
bytes_left -= len; ptr += len; size += len;
}
if (track_number > 0) {
unsigned char tracknumber[256];
snprintf(tracknumber, 256, "%d", track_number);
len = id3_fill_tframe(ptr, bytes_left, "TRK", 0, tracknumber);
if (len == 0)
return 0;
bytes_left -= len; ptr += len; size += len;
}
if (comment && strlen(comment) > 0) {
len = id3_fill_comment(ptr, bytes_left, 0,
NULL,
comment,
"eng");
if (len == 0)
return 0;
bytes_left -= len; ptr += len; size += len;
}
if (id3_fill_header(id3, sizeof(id3), size) == 0)
return 0;
len = file_write(outfile, id3, size + ID3_HEADER_SIZE);
if (len != size + ID3_HEADER_SIZE)
return 0;
return 1;
}
|
