File: id3v2.3.0.html

package info (click to toggle)
id3lib3.8.3 3.8.3-15
  • links: PTS, VCS
  • area: main
  • in suites: jessie, jessie-kfreebsd, wheezy
  • size: 5,588 kB
  • ctags: 3,080
  • sloc: cpp: 12,358; sh: 9,186; ansic: 7,240; makefile: 354; php: 325
file content (2257 lines) | stat: -rw-r--r-- 102,446 bytes parent folder | download | duplicates (5) 
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
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
 
<html><head><title>ID3v2 - Informal standard</title>
<style type="text/css">
body {font: 16px times}
h1 {font: 34px times}
h3 {font: 20px times; margin-left: 5%}
div.h5 {font: 16px times; font-weight: bold; margin-left: 8%}
div.t {margin-left: 10%; margin-right: 10%}
p.t {margin-left: 10%; margin-right: 10%}
p.ind {margin-left: 15%; margin-right: 15%}
pre {font: 16px times}
pre {margin-left: 40px}
a {font: 15px arial, helvetica; color: #CC5500; text-decoration: none}
</style>
<META name="description" content="ID3v2 informal standard.">
<META name="keywords" content="ID3v2">
</head><body bgcolor=white text=black>

<a name="top"> </a>

<br>&nbsp;
<p><table border=0 width=100%><tr><td>Informal standard<br>Document: id3v2.3.0.html</td><td align=right>
M. Nilsson<br>3rd February 1999</td></tr></table></p>

<h1 align=center>ID3 tag version 2.3.0</h1>

<a name="status"> </a>
<h3>Status of this document</h3>
<p class=t>
This document is an informal standard and replaces the <a href="#ID3v2">ID3v2.2.0</a>
standard. The informal standard is released so that
implementors could have a set standard before a formal standard is
set. The formal standard will use another version or revision number
if not identical to what is described in this document. The contents
in this document may change for clarifications but never for added or
altered functionallity.
</p><p class=t>
Distribution of this document is unlimited.
</p>

<a name="abstract"> </a>
<h3>Abstract</h3>
<p class=t>
This document describes the <a href="#ID3v2">ID3v2.3.0</a>, which is a more developed
version of the ID3v2 informal standard (version 2.2.0),
evolved from the ID3 tagging system. The ID3v2 offers a flexible way
of storing information about an audio file within itself to determine
its origin and contents. The information may be technical
information, such as equalisation curves, as well as related meta
information, such as title, performer, copyright etc.
</p>

<a name="sec1"> </a>
<h3>1.Table of contents</h3>

<p><center><table border=0 width="80%"><tr><td>
<dl>
<dt>2. <a href="#sec2">Conventions in this document</a></dt>
<dt>3. <a href="#sec3">ID3v2 overview</a>
 <dd> 3.1. <a href="#sec3.1">ID3v2 header</a></dd>
 <dd> 3.2. <a href="#sec3.2">ID3v2 extended header</a></dd>
 <dd> 3.3. <a href="#sec3.3">ID3v2 frames overview</a></dd>
 <dl><dd> 3.3.1. <a href="#sec3.3.1">Frame header flags</a></dd>
 <dd> 3.3.2. <a href="#sec3.3.2">Default flags</a></dd></dl></dt>
<dt>4. <a href="#sec4">Declared ID3v2 frames</a>
 <dd> 4.1. <a href="#sec4.1">Unique file identifier</a></dd>
 <dd> 4.2. <a href="#sec4.2">Text information frames</a>
 <dl><dd> 4.2.1. <a href="#sec4.2.1">Text information frames - details</a></dd>
 <dd> 4.2.2. <a href="#sec4.2.2">User defined text information frame</a></dd></dl></dd>
 <dd> 4.3. <a href="#sec4.3">URL link frames</a>
 <dl><dd>4.3.1. <a href="#sec4.3.1">URL link frames - details</a></dd>
 <dd>4.3.2. <a href="#sec4.3.2">User defined URL link frame</a></dd></dl></dd>
 <dd> 4.4. <a href="#sec4.4">Involved people list</a></dd>
 <dd> 4.5. <a href="#sec4.5">Music CD Identifier</a></dd>
 <dd> 4.6. <a href="#sec4.6">Event timing codes</a></dd>
 <dd> 4.7. <a href="#sec4.7">MPEG location lookup table</a></dd>
 <dd> 4.8. <a href="#sec4.8">Synced tempo codes</a></dd>
 <dd> 4.9. <a href="#sec4.9">Unsychronised lyrics/text transcription</a></dd>
 <dd> 4.10. <a href="#sec4.10">Synchronised lyrics/text</a></dd>
 <dd> 4.11. <a href="#sec4.11">Comments</a></dd>
 <dd> 4.12. <a href="#sec4.12">Relative volume adjustment</a></dd>
 <dd> 4.13. <a href="#sec4.13">Equalisation</a></dd>
 <dd> 4.14. <a href="#sec4.14">Reverb</a></dd>
 <dd> 4.15. <a href="#sec4.15">Attached picture</a></dd>
 <dd> 4.16. <a href="#sec4.16">General encapsulated object</a></dd>
 <dd> 4.17. <a href="#sec4.17">Play counter</a></dd>
 <dd> 4.18. <a href="#sec4.18">Popularimeter</a></dd>
 <dd> 4.19. <a href="#sec4.19">Recommended buffer size</a></dd>
 <dd> 4.20. <a href="#sec4.20">Audio encryption</a></dd>
 <dd> 4.21. <a href="#sec4.21">Linked information</a></dd>
 <dd> 4.22. <a href="#sec4.22">Position synchronisation frame</a></dd>
 <dd> 4.23. <a href="#sec4.23">Terms of use</a></dd>
 <dd> 4.24. <a href="#sec4.24">Ownership frame</a></dd>
 <dd> 4.25. <a href="#sec4.25">Commercial frame</a></dd>
 <dd> 4.26. <a href="#sec4.26">Encryption method registration</a></dd>
 <dd> 4.27. <a href="#sec4.27">Group identification registration</a></dd>
 <dd> 4.28. <a href="#sec4.28">Private frame</a></dd></dt>
<dt>5. <a href="#sec5">The 'unsynchronisation scheme'</a></dt>
<dt>6. <a href="#sec6">Copyright</a></dt>
<dt>7. <a href="#sec7">References</a></dt>
<dt>8. <a href="#sec8">Appendix</a>
 <dd> A. <a href="#secA">Appendix A - Genre List from ID3v1</a></dd></dt>
<dt>9. <a href="#sec9">Author's Address</a></dt>
</dl>
</td></tr></table></center></p>

<a name="sec2"> </a>
<h3>2.Conventions in this document</h3>
<p class=t>
In the examples, text within "" is a text string exactly as it
appears in a file. Numbers preceded with $ are hexadecimal and
numbers preceded with % are binary. $xx is used to indicate a byte
with unknown content. %x is used to indicate a bit with unknown
content. The most significant bit (MSB) of a byte is called 'bit 7'
and the least significant bit (LSB) is called 'bit 0'.
</p><p class=t>
A tag is the whole tag described in this document. A frame is a block
of information in the tag. The tag consists of a header, frames and
optional padding. A field is a piece of information; one value, a
string etc. A numeric string is a string that consists of the
characters 0-9 only.
</p>

<a name="sec3"> </a>
<h3>3.ID3v2 overview</h3>
<p class=t>
The two biggest design goals were to be able to implement ID3v2
without disturbing old software too much and that ID3v2 should be
as flexible and expandable as possible.
</p><p class=t>
The first criterion is met by the simple fact that the <a href="#MPEG">MPEG</a>
decoding software uses a syncsignal, embedded in the audiostream, to
'lock on to' the audio. Since the ID3v2 tag doesn't contain a valid
syncsignal, no software will attempt to play the tag. If, for any
reason, coincidence make a syncsignal appear within the tag it will
be taken care of by the 'unsynchronisation scheme' described in
<a href="#sec5">section 5</a>.
</p><p class=t>
The second criterion has made a more noticeable impact on the design
of the ID3v2 tag. It is constructed as a container for several
information blocks, called frames, whose format need not be known to
the software that encounters them. At the start of every frame there
is an identifier that explains the frames' format and content, and a
size descriptor that allows software to skip unknown frames.
</p><p class=t>
If a total revision of the ID3v2 tag should be needed, there is a
version number and a size descriptor in the ID3v2 header.
</p><p class=t>
The ID3 tag described in this document is mainly targeted at files
encoded with <a href="#MPEG">MPEG</a>-1/2 layer I, <a href="#MPEG">MPEG</a>-1/2 layer II, <a href="#MPEG">MPEG</a>-1/2 layer III
and MPEG-2.5, but may work with other types of encoded audio.
</p><p class=t>
The bitorder in ID3v2 is most significant bit first (MSB). The
byteorder in multibyte numbers is most significant byte first (e.g.
$12345678 would be encoded $12 34 56 78).
</p><p class=t>
It is permitted to include padding after all the final frame (at the
end of the ID3 tag), making the size of all the frames together
smaller than the size given in the head of the tag. A possible
purpose of this padding is to allow for adding a few additional
frames or enlarge existing frames within the tag without having to
rewrite the entire file. The value of the padding bytes must be $00.
</p>

<a name="sec3.1"> </a>
<h3>3.1.ID3v2 header</h3>
<p class=t>
The ID3v2 tag header, which should be the first information in the
file, is 10 bytes as follows:
</p>
<p><center><table border=0 width="70%">
<tr><td nowrap>ID3v2/file identifier</td><td rowspan=4>&nbsp;</td><td width="100%">"ID3"</td></tr>
<tr><td>ID3v2 version</td><td>$03 00</td></tr>
<tr><td>ID3v2 flags</td><td>%abc00000</td></tr>
<tr><td>ID3v2 size</td><td>4 * %0xxxxxxx</td></tr>
</table></center></p>
<p class=t>
The first three bytes of the tag are always "ID3" to indicate that
this is an ID3v2 tag, directly followed by the two version bytes. The
first byte of ID3v2 version is it's major version, while the second
byte is its revision number. In this case this is ID3v2.3.0. All
revisions are backwards compatible while major versions are not. If
software with ID3v2.2.0 and below support should encounter version
three or higher it should simply ignore the whole tag. Version and
revision will never be $FF.
</p><p class=t>
The version is followed by one the ID3v2 flags field, of which
currently only three flags are used.
</p>
<p class=t>
a - Unsynchronisation
</p><p class=ind>
Bit 7 in the 'ID3v2 flags' indicates whether or not unsynchronisation is used (see <a href="#sec5">section 5</a> for details); a set bit indicates usage.</p>
<p class=t>
b - Extended header
</p><p class=ind>
 The second bit (bit 6) indicates whether or not the header is
 followed by an extended header. The extended header is described in
 <a href="#sec3.2">section 3.2</a>.
</p>
<p class=t>
c - Experimental indicator
</p><p class=ind>
 The third bit (bit 5) should be used as an 'experimental
 indicator'. This flag should always be set when the tag is in an
 experimental stage.
</p><p class=t>
All the other flags should be cleared. If one of these undefined
flags are set that might mean that the tag is not readable for a
parser that does not know the flags function.
</p><p class=t>
The ID3v2 tag size is encoded with four bytes where the most
significant bit (bit 7) is set to zero in every byte, making a total
of 28 bits. The zeroed bits are ignored, so a 257 bytes long tag is
represented as $00 00 02 01.
</p><p class=t>
The ID3v2 tag size is the size of the complete tag after
unsychronisation, including padding, excluding the header but not
excluding the extended header (total tag size - 10). Only 28 bits
(representing up to 256MB) are used in the size description to avoid
the introducuction of 'false syncsignals'.
</p><p class=t>
An ID3v2 tag can be detected with the following pattern:<br>
 $49 44 33 yy yy xx zz zz zz zz<br>
Where yy is less than $FF, xx is the 'flags' byte and zz is less than
$80.
</p>

<a name="sec3.2"> </a>
<h3>3.2.ID3v2 extended header</h3>
<p class=t>
The extended header contains information that is not vital to the
correct parsing of the tag information, hence the extended header is
optional.
</p>
<p><center><table border=0 width="70%">
<tr><td nowrap> Extended header size</td><td rowspan=3>&nbsp;</td><td width=100%>$xx xx xx xx</td></tr>
<tr><td>Extended Flags</td><td>$xx xx</td></tr>
<tr><td>Size of padding</td><td>$xx xx xx xx</tr>
</table></center></p>
<p class=t>
Where the 'Extended header size', currently 6 or 10 bytes, excludes
itself. The 'Size of padding' is simply the total tag size excluding
the frames and the headers, in other words the padding. The extended
header is considered separate from the header proper, and as such is
subject to unsynchronisation.
</p><p class=t>
The extended flags are a secondary flag set which describes further
attributes of the tag. These attributes are currently defined as
follows
</p><p class=ind>
 %x0000000 00000000
</p>
<p class=t>
x - CRC data present
</p><p class=ind>
 If this flag is set four bytes of CRC-32 data is appended to the
 extended header. The CRC should be calculated before
 unsynchronisation on the data between the extended header and the
 padding, i.e. the frames and only the frames.
</p>
<p><center><table border=0 width="70%">
<tr><td nowrap> Total frame CRC</td><td>&nbsp;</td><td>$xx xx xx xx</td></tr>
</table></center></p>


<a name="sec3.3"> </a>
<h3>3.3.ID3v2 frame overview</h3>
<p class=t>
As the tag consists of a tag header and a tag body with one or more
frames, all the frames consists of a frame header followed by one or
more fields containing the actual information. The layout of the
frame header:
</p>
<p><center><table border=0 width="70%">
<tr><td nowrap> Frame ID</td><td rowspan=3>&nbsp;</td><td width="100%">$xx xx xx xx (four characters)</td></tr>
<tr><td>Size</td><td>$xx xx xx xx</td></tr>
<tr><td>Flags</td><td>$xx xx</td></tr>
</table></center></p>
<p class=t>
The frame ID made out of the characters capital A-Z and 0-9.
Identifiers beginning with "X", "Y" and "Z" are for experimental use
and free for everyone to use, without the need to set the
experimental bit in the tag header. Have in mind that someone else
might have used the same identifier as you. All other identifiers are
either used or reserved for future use.
</p><p class=t>
The frame ID is followed by a size descriptor, making a total header
size of ten bytes in every frame. The size is calculated as frame
size excluding frame header (frame size - 10).
</p><p class=t>
In the frame header the size descriptor is followed by two flags
bytes. These flags are described in <a href="#sec3.3.1">section 3.3.1.</a>
</p><p class=t>
There is no fixed order of the frames' appearance in the tag,
although it is desired that the frames are arranged in order of
significance concerning the recognition of the file. An example of
such order: <a href="#sec4.1">UFID</a>, <a href="#TIT2">TIT2</a>, <a href="#sec4.5">MCDI</a>, <a href="#TRCK">TRCK</a> ...
</p><p class=t>
A tag must contain at least one frame. A frame must be at least 1
byte big, excluding the header.
</p><p class=t>
If nothing else is said a string is represented as
<a href="#ISO-8859-1">ISO-8859-1</a> characters in the range $20 - $FF. Such strings are
represented as &lt;text string&gt;, or &lt;full text string&gt; if newlines are
allowed, in the frame descriptions. All <a href="#UNICODE">Unicode</a> strings use
16-bit unicode 2.0 (ISO/IEC 10646-1:1993, UCS-2). Unicode strings
must begin with the Unicode BOM ($FF FE or $FE FF) to identify the
byte order.
</p><p class=t>
All numeric strings and <a href="#URL">URLs</a> are always encoded as <a href="#ISO-8859-1">ISO-8859-1</a>.
Terminated strings are terminated with $00 if encoded with <a href="#ISO-8859-1">ISO-8859-1</a>
and $00 00 if encoded as unicode. If nothing else is said newline
character is forbidden. In <a href="#ISO-8859-1">ISO-8859-1</a> a new line is represented, when
allowed, with $0A only. Frames that allow different types of text
encoding have a text encoding description byte directly after the
frame size. If <a href="#ISO-8859-1">ISO-8859-1</a> is used this byte should be $00, if Unicode
is used it should be $01. Strings dependent on encoding is
represented as &lt;text string according to encoding&gt;, or &lt;full text
string according to encoding&gt; if newlines are allowed. Any empty
<a href="#UNICODE">Unicode</a> strings which are NULL-terminated may have the Unicode BOM
followed by a Unicode NULL ($FF FE 00 00 or $FE FF 00 00).
</p><p class=t>
The three byte language field is used to describe the language of the
frame's content, according to <a href="#ISO-639-2">ISO-639-2</a>.
</p><p class=t>
All <a href="#URL">URLs</a> may be relative, e.g. "picture.png", "../doc.txt".
</p><p class=t>
If a frame is longer than it should be, e.g. having more fields than
specified in this document, that indicates that additions to the
frame have been made in a later version of the ID3v2 standard. This
is reflected by the revision number in the header of the tag.
</p>

<a name="sec3.3.1"> </a>
<h3>3.3.1.Frame header flags</h3>
<p class=t>
In the frame header the size descriptor is followed by two flags
bytes. All unused flags must be cleared. The first byte is for
'status messages' and the second byte is for encoding purposes. If an
unknown flag is set in the first byte the frame may not be changed
without the bit cleared. If an unknown flag is set in the second byte
it is likely to not be readable. The flags field is defined as
follows.
</p><p class=ind>
 %abc00000 %ijk00000
</p>
<p class=t>
a - Tag alter preservation
</p><p class=ind>
 This flag tells the software what to do with this frame if it is
 unknown and the tag is altered in any way. This applies to all
 kinds of alterations, including adding more padding and reordering
 the frames.</p>
<p><center><table border=0 width="70%">
<tr><td>0&nbsp;</td><td>Frame should be preserved.</td></tr>
<tr><td>1</td><td>Frame should be discarded.</td></tr>
</table></center>
</p>
<p class=t>
b - File alter preservation
</p><p class=ind>
 This flag tells the software what to do with this frame if it is
 unknown and the file, excluding the tag, is altered. This does not
 apply when the audio is completely replaced with other audio data.</p>
<p><center><table border=0 width="70%">
<tr><td>0&nbsp;</td><td>Frame should be preserved.</td></tr>
<tr><td>1</td><td>Frame should be discarded.</td></tr>
</table></center>
</p>
<p class=t>
c - Read only
</p><p class=ind>
This flag, if set, tells the software that the contents of this
frame is intended to be read only. Changing the contents might
break something, e.g. a signature. If the contents are changed,
without knowledge in why the frame was flagged read only and
without taking the proper means to compensate, e.g. recalculating
the signature, the bit should be cleared.
</p>
<p class=t>
i - Compression
</p>
<p class=ind>This flag indicates whether or not the frame is compressed.</p>
<p><center><table border=0 width="70%">
<tr><td>0&nbsp;</td><td>Frame is not compressed.</td></tr>
<tr><td>1</td><td>Frame is compressed using <a href="#ZLIB">zlib</a> with 4 bytes for 'decompressed size' appended to the frame header.</td></tr>
</table></center>
</p>
<p class=t>
j - Encryption
</p><p class=ind>
This flag indicates wether or not the frame is enrypted. If set
one byte indicating with which method it was encrypted will be
appended to the frame header. See <a href="#sec4.26">section 4.26.</a> for more
information about encryption method registration.
</p><p><center><table border=0 width="70%">
<tr><td>0&nbsp;</td><td>Frame is not encrypted.</td></tr>
<tr><td>1</td><td>Frame is encrypted.</td></tr>
</table></center>
</p>
<p class=t>
k - Grouping identity
</p><p class=ind>
This flag indicates whether or not this frame belongs in a group
with other frames. If set a group identifier byte is added to the
frame header. Every frame with the same group identifier belongs
to the same group.
</p><p><center><table border=0 width="70%">
<tr><td>0&nbsp;</td><td>Frame does not contain group information</td></tr>
<tr><td>1</td><td>Frame contains group information</td></tr>
</table></center>
</p>
<p class=t>
Some flags indicates that the frame header is extended with
additional information. This information will be added to the frame
header in the same order as the flags indicating the additions. I.e.
the four bytes of decompressed size will preceed the encryption
method byte. These additions to the frame header, while not included
in the frame header size but are included in the 'frame size' field,
are not subject to encryption or compression.
</p>

<a name="sec3.3.2"> </a>
<h3>3.3.2.Default flags</h3>
<p class=t>
The default settings for the frames described in this document can be
divided into the following classes. The flags may be set differently
if found more suitable by the software.
</p><p class=t>
 1. Discarded if tag is altered, discarded if file is altered.
</p><p class=ind>
 None.
</p><p class=t>
 2. Discarded if tag is altered, preserved if file is altered.
</p><p class=ind>
 None.
</p><p class=t>
 3. Preserved if tag is altered, discarded if file is altered.
</p><p class=ind>
 <a href="#sec4.21>AENC</a>, <a href="#sec4.6">ETCO</a>, <a href="#sec4.13">EQUA</a>, <a href="#sec4.7">MLLT</a>, <a href="#sec4.22">POSS</a>, <a href="#4.10">SYLT</a>, <a href="#sec4.8">SYTC</a>, <a href="#4.12">RVAD</a>, <a href="#TENC">TENC</a>, <a href="#TLEN">TLEN</a>, <a href="#TSIZ">TSIZ</a>
</p><p class=t>
 4. Preserved if tag is altered, preserved if file is altered.
</p><p class=ind>
 The rest of the frames.
</p>

<a name="sec4"> </a>
<h3>4.Declared ID3v2 frames</h3>
</p><p class=t>
The following frames are declared in this draft.
</p><p><center><table border=0 width="70%">
<tr><td>4.20</td><td>AENC</td><td width="100%"><a href="#sec4.20"> Audio encryption</a></td></tr>
<tr><td>4.15</td><td>APIC</td><td><a href="#sec4.15">Attached picture</a></td></tr>

<tr><td>4.11</td><td>COMM</td><td><a href="#sec4.11">Comments</a></td></tr>
<tr><td>4.25</td><td>COMR</td><td><a href="#sec4.25">Commercial frame</a></td></tr>

<tr><td>4.26</td><td>ENCR</td><td><a href="#sec4.26">Encryption method registration</a></td></tr>
<tr><td>4.13</td><td>EQUA</td><td><a href="#sec4.13">Equalization</a></td></tr>
<tr><td>4.6 </td><td>ETCO</td><td><a href="#sec4.6">Event timing codes</a></td></tr>

<tr><td>4.16</td><td>GEOB</td><td><a href="#sec4.16">General encapsulated object</a></td></tr>
<tr><td>4.27</td><td>GRID</td><td><a href="#sec4.27">Group identification registration</a></td></tr>

<tr><td>4.4 </td><td>IPLS</td><td><a href="#sec4.4">Involved people list</a></td></tr>

<tr><td>4.21</td><td>LINK</td><td><a href="#sec4.21">Linked information</a></td></tr>

<tr><td>4.5 </td><td>MCDI</td><td><a href="#sec4.5">Music CD identifier</a></td></tr>
<tr><td>4.7 </td><td>MLLT</td><td><a href="#sec4.7">MPEG location lookup table</a></td></tr>

<tr><td>4.24</td><td>OWNE</td><td><a href="#sec4.24">Ownership frame</a></td></tr>

<tr><td>4.28</td><td>PRIV</td><td><a href="#sec4.28">Private frame</a></td></tr>
<tr><td>4.17</td><td>PCNT</td><td><a href="#sec4.17">Play counter</a></td></tr>
<tr><td>4.18</td><td>POPM</td><td><a href="#sec4.18">Popularimeter</a></td></tr>
<tr><td>4.22</td><td>POSS</td><td><a href="#sec4.22">Position synchronisation frame</a></td></tr>

<tr><td>4.19</td><td>RBUF</td><td><a href="#sec4.19">Recommended buffer size</a></td></tr>
<tr><td>4.12</td><td>RVAD</td><td><a href="#sec4.12">Relative volume adjustment</a></td></tr>
<tr><td>4.14</td><td>RVRB</td><td><a href="#sec4.14">Reverb</a></td></tr>

<tr><td>4.10</td><td>SYLT</td><td><a href="#sec4.10">Synchronized lyric/text</a></td></tr>
<tr><td>4.8 </td><td>SYTC</td><td><a href="#sec4.8">Synchronized tempo codes</a></td></tr>

<tr><td>4.2.1</td><td>TALB</td><td><a href="#TALB">Album/Movie/Show title</a></td></tr>
<tr><td>4.2.1</td><td>TBPM</td><td><a href="#TBPM">BPM (beats per minute)</a></td></tr>
<tr><td>4.2.1</td><td>TCOM</td><td><a href="#TCOM">Composer</a></td></tr>
<tr><td>4.2.1</td><td>TCON</td><td><a href="#TCON">Content type</a></td></tr>
<tr><td>4.2.1</td><td>TCOP</td><td><a href="#TCOP">Copyright message</a></td></tr>
<tr><td>4.2.1</td><td>TDAT</td><td><a href="#TDAT">Date</a></td></tr>
<tr><td>4.2.1</td><td>TDLY</td><td><a href="#TDLY">Playlist delay</a></td></tr>
<tr><td>4.2.1</td><td>TENC</td><td><a href="#TENC">Encoded by</a></td></tr>
<tr><td>4.2.1</td><td>TEXT</td><td><a href="#TEXT">Lyricist/Text writer</a></td></tr>
<tr><td>4.2.1</td><td>TFLT</td><td><a href="#TFLT">File type</a></td></tr>
<tr><td>4.2.1</td><td>TIME</td><td><a href="#TIME">Time</a></td></tr>
<tr><td>4.2.1</td><td>TIT1</td><td><a href="#TIT1">Content group description</a></td></tr>
<tr><td>4.2.1</td><td>TIT2</td><td><a href="#TIT2">Title/songname/content description</a></td></tr>
<tr><td>4.2.1</td><td>TIT3</td><td><a href="#TIT3">Subtitle/Description refinement</a></td></tr>
<tr><td>4.2.1</td><td>TKEY</td><td><a href="#TKEY">Initial key</a></td></tr>
<tr><td>4.2.1</td><td>TLAN</td><td><a href="#TLAN">Language(s)</a></td></tr>
<tr><td>4.2.1</td><td>TLEN</td><td><a href="#TLEN">Length</a></td></tr>
<tr><td>4.2.1</td><td>TMED</td><td><a href="#TMED">Media type</a></td></tr>
<tr><td>4.2.1</td><td>TOAL</td><td><a href="#TOAL">Original album/movie/show title</a></td></tr>
<tr><td>4.2.1</td><td>TOFN</td><td><a href="#TOFN">Original filename</a></td></tr>
<tr><td>4.2.1</td><td>TOLY</td><td><a href="#TOLY">Original lyricist(s)/text writer(s)</a></td></tr>
<tr><td>4.2.1</td><td>TOPE</td><td><a href="#TOPE">Original artist(s)/performer(s)</a></td></tr>
<tr><td>4.2.1</td><td>TORY</td><td><a href="#TORY">Original release year</a></td></tr>
<tr><td>4.2.1</td><td>TOWN</td><td><a href="#TOWN">File owner/licensee</a></td></tr>
<tr><td>4.2.1</td><td>TPE1</td><td><a href="#TPE1">Lead performer(s)/Soloist(s)</a></td></tr>
<tr><td>4.2.1</td><td>TPE2</td><td><a href="#TPE2">Band/orchestra/accompaniment</a></td></tr>
<tr><td>4.2.1</td><td>TPE3</td><td><a href="#TPE3">Conductor/performer refinement</a></td></tr>
<tr><td>4.2.1</td><td>TPE4</td><td><a href="#TPE4">Interpreted, remixed, or otherwise modified by</a></td></tr>
<tr><td>4.2.1</td><td>TPOS</td><td><a href="#TPOS">Part of a set</a></td></tr>
<tr><td>4.2.1</td><td>TPUB</td><td><a href="#TPUB">Publisher</a></td></tr>
<tr><td>4.2.1</td><td>TRCK</td><td><a href="#TRCK">Track number/Position in set</a></td></tr>
<tr><td>4.2.1</td><td>TRDA</td><td><a href="#TRDA">Recording dates</a></td></tr>
<tr><td>4.2.1</td><td>TRSN</td><td><a href="#TRSN">Internet radio station name</a></td></tr>
<tr><td>4.2.1</td><td>TRSO</td><td><a href="#TRSO">Internet radio station owner</a></td></tr>
<tr><td>4.2.1</td><td>TSIZ</td><td><a href="#TSIZ">Size</a></td></tr>
<tr><td>4.2.1</td><td>TSRC</td><td><a href="#TSRC">ISRC (international standard recording code)</a></td></tr>
<tr><td>4.2.1</td><td>TSSE</td><td><a href="#TSSE">Software/Hardware and settings used for encoding</a></td></tr>
<tr><td>4.2.1</td><td>TYER</td><td><a href="#TYER">Year</a></td></tr>
<tr><td>4.2.2</td><td>TXXX</td><td><a href="#TXXX">User defined text information frame</a></td></tr>

<tr><td>4.1 </td><td>UFID</td><td><a href="#sec4.1">Unique file identifier</td></tr>
<tr><td>4.23</td><td>USER</td><td><a href="#sec4.23">Terms of use</td></tr>
<tr><td>4.9 </td><td>USLT</td><td><a href="#sec4.9">Unsychronized lyric/text transcription</td></tr>

<tr><td>4.3.1</td><td>WCOM</td><td><a href="#WCOM">Commercial information</a></td></tr>
<tr><td>4.3.1</td><td>WCOP</td><td><a href="#WCOP">Copyright/Legal information</a></td></tr>
<tr><td>4.3.1</td><td>WOAF</td><td><a href="#WOAF">Official audio file webpage</a></td></tr>
<tr><td>4.3.1</td><td>WOAR</td><td><a href="#WOAR">Official artist/performer webpage</a></td></tr>
<tr><td>4.3.1</td><td>WOAS</td><td><a href="#WOAS">Official audio source webpage</a></td></tr>
<tr><td>4.3.1</td><td>WORS</td><td><a href="#WORS">Official internet radio station homepage</a></td></tr>
<tr><td>4.3.1</td><td>WPAY</td><td><a href="#WPAY">Payment</a></td></tr>
<tr><td>4.3.1</td><td>WPUB</td><td><a href="#WPUB">Publishers official webpage</a></td></tr>
<tr><td>4.3.2</td><td>WXXX</td><td><a href="#WXXX">User defined URL link frame</a></td></tr>
</table></center>
</p>

<a name="sec4.1"> </a>
<h3>4.1.Unique file identifier</h3>
<p class=t>
This frame's purpose is to be able to identify the audio file in a
database that may contain more information relevant to the content.
Since standardisation of such a database is beyond this document, all
frames begin with a null-terminated string with a <a href="#URL">URL</a>
containing an email address, or a link to a location where an email
address can be found, that belongs to the organisation responsible
for this specific database implementation. Questions regarding the
database should be sent to the indicated email address. The <a href="#URL">URL</a>
should not be used for the actual database queries. The string
"http://www.id3.org/dummy/ufid.html" should be used for tests.
Software that isn't told otherwise may safely remove such frames. The
'Owner identifier' must be non-empty (more than just a termination).
The 'Owner identifier' is then followed by the actual identifier,
which may be up to 64 bytes. There may be more than one "UFID" frame
in a tag, but only one with the same 'Owner identifier'.
</p>
<p><center><table border=0 width="70%">
<tr><td colspan=2>&lt;Header for 'Unique file identifier', ID: "UFID"&gt;</td></tr>
<tr><td>Owner identifier</td><td width="80%">&lt;text string&gt; $00</td></tr>
<tr><td>Identifier</td><td>&lt;up to 64 bytes binary data&gt;</td></tr>
</table></center></p>

<a name="sec4.2"> </a>
<h3>4.2.Text information frames</h3>
<p class=t>
The text information frames are the most important frames, containing
information like artist, album and more. There may only be one text
information frame of its kind in an tag. If the textstring is
followed by a termination ($00 (00)) all the following information
should be ignored and not be displayed. All text frame identifiers
begin with "T". Only text frame identifiers begin with "T", with the
exception of the "<a href="#sec4.2.2">TXXX</a>" frame. All the text information frames have
the following format:
</p>
<p><center><table border=0 width="70%">
<tr><td colspan=2> &lt;Header for 'Text information frame', ID: "T000" - "TZZZ", excluding "TXXX" described in 4.2.2.&gt;</td></tr>
<tr><td>Text encoding</td><td width="80%">$xx</td></tr>
<tr><td>Information </td><td>&lt;text string according to encoding&gt;</td></tr>
</table></center></p>

<a name="sec4.2.1"> </a>
<h3>4.2.1.Text information frames - details</h3>
<p>
<a name="TALB"> </a>
<div class=h5>TALB</div>
<div class=t>
The 'Album/Movie/Show title' frame is intended for the title of the
recording(/source of sound) which the audio in the file is taken
from.
</div>
</p>

<p>
<a name="TBPM"> </a>
<div class=h5>TBPM</div>
<div class=t>The 'BPM' frame contains the number of beats per minute in the
mainpart of the audio. The BPM is an integer and represented as a
numerical string.</div>
</p>

<p>
<a name="TCOM"> </a>
<div class=h5>TCOM</div>
<div class=t>The 'Composer(s)' frame is intended for the name of the composer(s).
They are seperated with the "/" character.</div>
</p>

<p>
<a name="TCON"> </a>
<div class=h5>TCON</div>
<div class=t>The 'Content type', which previously was
stored as a one byte numeric value only, is now a numeric string. You
may use one or several of the types as ID3v1.1 did or, since the
category list would be impossible to maintain with accurate and up to
date categories, define your own.
</div></p>
<p><div class=t>
References to the ID3v1 genres can be made by, as first byte, enter
"(" followed by a number from the genres list (<a href="#secA">appendix A</a>) and
ended with a ")" character. This is optionally followed by a
refinement, e.g. "(21)" or "(4)Eurodisco". Several references can be
made in the same frame, e.g. "(51)(39)". If the refinement should
begin with a "(" character it should be replaced with "((", e.g. "((I
can figure out any genre)" or "(55)((I think...)". The following new
content types is defined in ID3v2 and is implemented in the same way
as the numerig content types, e.g. "(RX)".</div>
</p>
<p><center><table border=0 width="70%">
<tr><td>RX</td><td width="100%">Remix</td></tr>
<tr><td>CR</td><td>Cover</td></tr>
</table></center>
</p>

<p>
<a name="TCOP"> </a>
<div class=h5>TCOP</div>
<div class=t>The 'Copyright message' frame, which must begin with a year and a
space character (making five characters), is intended for the
copyright holder of the original sound, not the audio file itself.
The absence of this frame means only that the copyright information
is unavailable or has been removed, and must not be interpreted to
mean that the sound is public domain. Every time this field is
displayed the field must be preceded with "Copyright &copy; ".</div>
</p>

<p>
<a name="TDAT"> </a>
<div class=h5>TDAT</div>
<div class=t>The 'Date' frame is a numeric string in the DDMM format containing
the date for the recording. This field is always four characters
long.</div>
</p>

<p>
<a name="TDLY"> </a>
<div class=h5>TDLY</div>
<div class=t>The 'Playlist delay' defines the numbers of milliseconds of silence
between every song in a playlist. The player should use the "ETC"
frame, if present, to skip initial silence and silence at the end of
the audio to match the 'Playlist delay' time. The time is represented
as a numeric string.</div>
</p>

<p>
<a name="TENC"> </a>
<div class=h5>TENC</div>
<div class=t>The 'Encoded by' frame contains the name of the person or
organisation that encoded the audio file. This field may contain a
copyright message, if the audio file also is copyrighted by the
encoder.</div>
</p>

<p>
<a name="TEXT"> </a>
<div class=h5>TEXT</div>
<div class=t>The 'Lyricist(s)/Text writer(s)' frame is intended for the writer(s)
of the text or lyrics in the recording. They are seperated with the
"/" character.</div>
</p>

<p>
<a name="TFLT"> </a>
<div class=h5>TFLT</div>
<div class=t>The 'File type' frame indicates which type of audio this tag defines.
The following type and refinements are defined:
</div></p>
<p><center><table border=0 width="70%">
<tr><td>MPG</td><td rowspan=8>&nbsp;</td><td width="100%">MPEG Audio</td></tr>
<tr><td align=right>/1</td><td>MPEG 1/2 layer I</td></tr>
<tr><td align=right>/2</td><td>MPEG 1/2 layer II</td></tr>
<tr><td align=right>/3</td><td>MPEG 1/2 layer III</td></tr>
<tr><td align=right>/2.5</td><td>MPEG 2.5</td></tr>
<tr><td align=right>&nbsp;/AAC</td><td>Advanced audio compression</td></tr>
<tr><td>VQF</td><td>Transform-domain Weighted Interleave Vector Quantization</td></tr>
<tr><td>PCM</td><td>Pulse Code Modulated audio</td></tr>
</table></center></p>
<p><div class=t>
but other types may be used, not for these types though. This is used
in a similar way to the predefined types in the "TMED" frame, but
without parentheses. If this frame is not present audio type is
assumed to be "MPG".</div>
</p>

<p>
<a name="TIME"> </a>
<div class=h5>TIME</div>
<div class=t>The 'Time' frame is a numeric string in the HHMM format containing
the time for the recording. This field is always four characters
long.</div>
</p>

<p>
<a name="TIT1"> </a>
<div class=h5>TIT1</div>
<div class=t>The 'Content group description' frame is used if the sound belongs to
a larger category of sounds/music. For example, classical music is
often sorted in different musical sections (e.g. "Piano Concerto",
"Weather - Hurricane").</div>
</p>

<p>
<a name="TIT2"> </a>
<div class=h5>TIT2</div>
<div class=t>The 'Title/Songname/Content description' frame is the actual name of
the piece (e.g. "Adagio", "Hurricane Donna").</div>
</p>

<p>
<a name="TIT3"> </a>
<div class=h5>TIT3</div>
<div class=t>The 'Subtitle/Description refinement' frame is used for information
directly related to the contents title (e.g. "Op. 16" or "Performed
live at Wembley").</div>
</p>

<p>
<a name="TKEY"> </a>
<div class=h5>TKEY</div>
<div class=t>The 'Initial key' frame contains the musical key in which the sound
starts. It is represented as a string with a maximum length of three
characters. The ground keys are represented with "A","B","C","D","E",
"F" and "G" and halfkeys represented with "b" and "#". Minor is
represented as "m". Example "Cbm". Off key is represented with an "o"
only.</div>
</p>

<p>
<a name="TLAN"> </a>
<div class=h5>TLAN</div>
<div class=t>The 'Language(s)' frame should contain the languages of the text or
lyrics spoken or sung in the audio. The language is represented with
three characters according to <a href="#ISO-639-2">ISO-639-2</a>. If more than one language is
used in the text their language codes should follow according to
their usage.</div>
</p>

<p>
<a name="TLEN"> </a>
<div class=h5>TLEN</div>
<div class=t>The 'Length' frame contains the length of the audiofile in
milliseconds, represented as a numeric string.</div>
</p>

<p>
<a name="TMED"> </a>
<div class=h5>TMED</div>
<div class=t>The 'Media type' frame describes from which media the sound
originated. This may be a text string or a reference to the
predefined media types found in the list below. References are made
within "(" and ")" and are optionally followed by a text refinement,
e.g. "(MC) with four channels". If a text refinement should begin
with a "(" character it should be replaced with "((" in the same way
as in the "TCO" frame. Predefined refinements is appended after the
media type, e.g. "(CD/A)" or "(VID/PAL/VHS)".</div>
</p>
<p><center><table border=0 width="70%">
<tr><td>DIG</td><td rowspan=67>&nbsp;</td><td width="100%">Other digital media</td></tr>
<tr valign=top><td align=right>/A<br>&nbsp;</td><td>Analog transfer from media</td></tr>

<tr><td>ANA</td><td>Other analog media</td></tr>
<tr><td align=right>/WAC</td><td>Wax cylinder</td></tr>
<tr valign=top><td align=right>/8CA<br>&nbsp;</td><td>8-track tape cassette</td></tr>

<tr><td>CD</td><td>CD</td></tr>
<tr><td align=right>/A</td><td>Analog transfer from media</td></tr>
<tr><td align=right>/DD</td><td>DDD</td></tr>
<tr><td align=right>/AD</td><td>ADD</td></tr>
<tr valign=top><td align=right>/AA<br>&nbsp;</td><td>AAD</td></tr>

<tr><td>LD</td><td>Laserdisc</td></tr>
<tr valign=top><td align=right>/A<br>&nbsp;</td><td>Analog transfer from media</td></tr>

<tr><td>TT</td><td>Turntable records</td></tr>
<tr><td align=right>/33</td><td>33.33 rpm</td></tr>
<tr><td align=right>/45</td><td>45 rpm</td></tr>
<tr><td align=right>/71</td><td>71.29 rpm</td></tr>
<tr><td align=right>/76</td><td>76.59 rpm</td></tr>
<tr><td align=right>/78</td><td>78.26 rpm</td></tr>
<tr valign=top><td align=right>/80<br>&nbsp;</td><td>80 rpm</td></tr>

<tr><td>MD</td><td>MiniDisc</td></tr>
<tr valign=top><td align=right>/A<br>&nbsp;</td><td>Analog transfer from media</td></tr>

<tr><td>DAT</td><td>DAT</td></tr>
<tr><td align=right>/A</td><td>Analog transfer from media</td></tr>
<tr><td align=right>/1</td><td>standard, 48 kHz/16 bits, linear</td></tr>
<tr><td align=right>/2</td><td>mode 2, 32 kHz/16 bits, linear</td></tr>
<tr><td align=right>/3</td><td>mode 3, 32 kHz/12 bits, nonlinear, low speed</td></tr>
<tr><td align=right>/4</td><td>mode 4, 32 kHz/12 bits, 4 channels</td></tr>
<tr><td align=right>/5</td><td>mode 5, 44.1 kHz/16 bits, linear</td></tr>
<tr valign=top><td align=right>/6<br>&nbsp;</td><td>mode 6, 44.1 kHz/16 bits, 'wide track' play</td></tr>

<tr><td>DCC</td><td>DCC</td></tr>
<tr valign=top><td align=right>/A<br>&nbsp;</td><td>Analog transfer from media</td></tr>

<tr><td>DVD</td><td>DVD</td></tr>
<tr valign=top><td align=right>/A<br>&nbsp;</td><td>Analog transfer from media</td></tr>

<tr><td>TV</td><td>Television</td></tr>
<tr><td align=right>/PAL</td><td>PAL</td></tr>
<tr><td align=right>/NTSC</td><td>NTSC</td></tr>
<tr valign=top><td align=right>&nbsp;/SECAM<br>&nbsp;</td><td>SECAM</td></tr>

<tr><td>VID</td><td>Video</td></tr>
<tr><td align=right>/PAL</td><td>PAL</td></tr>
<tr><td align=right>/NTSC</td><td>NTSC</td></tr>
<tr><td align=right>/SECAM</td><td>SECAM</td></tr>
<tr><td align=right>/VHS</td><td>VHS</td></tr>
<tr><td align=right>/SVHS</td><td>S-VHS</td></tr>
<tr valign=top><td align=right>/BETA<br>&nbsp;</td><td>BETAMAX</td></tr>

<tr><td>RAD</td><td>Radio</td></tr>
<tr><td align=right>/FM</td><td>FM</td></tr>
<tr><td align=right>/AM</td><td>AM</td></tr>
<tr><td align=right>/LW</td><td>LW</td></tr>
<tr valign=top><td align=right>/MW<br>&nbsp;</td><td>MW</td></tr>

<tr><td>TEL</td><td>Telephone</td></tr>
<tr valign=top><td align=right>/I<br>&nbsp;</td><td>ISDN</td></tr>

<tr><td>MC</td><td>MC (normal cassette)</td></tr>
<tr><td align=right>/4</td><td>4.75 cm/s (normal speed for a two sided cassette)</td></tr>
<tr><td align=right>/9</td><td>9.5 cm/s</td></tr>
<tr><td align=right>/I</td><td>Type I cassette (ferric/normal)</td></tr>
<tr><td align=right>/II</td><td>Type II cassette (chrome)</td></tr>
<tr><td align=right>/III</td><td>Type III cassette (ferric chrome)</td></tr>
<tr valign=top><td align=right>/IV<br>&nbsp;</td><td>Type IV cassette (metal)</td></tr>

<tr><td>REE</td><td>Reel</td></tr>
<tr><td align=right>/9</td><td>9.5 cm/s</td></tr>
<tr><td align=right>/19</td><td>19 cm/s</td></tr>
<tr><td align=right>/38</td><td>38 cm/s</td></tr>
<tr><td align=right>/76</td><td>76 cm/s</td></tr>
<tr><td align=right>/I</td><td>Type I cassette (ferric/normal)</td></tr>
<tr><td align=right>/II</td><td>Type II cassette (chrome)</td></tr>
<tr><td align=right>/III</td><td>Type III cassette (ferric chrome)</td></tr>
<tr><td align=right>/IV<br>&nbsp;</td><td>Type IV cassette (metal)</td></tr>
</table></center>
</p>

<p>
<a name="TOAL"> </a>
<div class=h5>TOAL</div>
<div class=t>The 'Original album/movie/show title' frame is intended for the title
of the original recording (or source of sound), if for example the
music in the file should be a cover of a previously released song.
</p></div>

<p>
<a name="TOFN"> </a>
<div class=h5>TOFN</div>
<div class=t>The 'Original filename' frame contains the preferred filename for the
file, since some media doesn't allow the desired length of the
filename. The filename is case sensitive and includes its suffix.</div>
</p>

<p>
<a name="TOLY"> </a>
<div class=h5>TOLY</div>
<div class=t>The 'Original lyricist(s)/text writer(s)' frame is intended for the
text writer(s) of the original recording, if for example the music in
the file should be a cover of a previously released song. The text
writers are seperated with the "/" character.</div>
</p>

<p>
<a name="TOPE"> </a>
<div class=h5>TOPE</div>
<div class=t>The 'Original artist(s)/performer(s)' frame is intended for the
performer(s) of the original recording, if for example the music in
the file should be a cover of a previously released song. The
performers are seperated with the "/" character.</div>
</p>

<p>
<a name="TORY"> </a>
<div class=h5>TORY</div>
<div class=t>The 'Original release year' frame is intended for the year when the
original recording, if for example the music in the file should be a
cover of a previously released song, was released. The field is
formatted as in the "TYER" frame.</div>
</p>

<p>
<a name="TOWN"> </a>
<div class=h5>TOWN</div>
<div class=t>The 'File owner/licensee' frame contains the name of the owner or
licensee of the file and it's contents.</div>
</p>

<p>
<a name="TPE1"> </a>
<div class=h5>TPE1</div>
<div class=t>The 'Lead artist(s)/Lead performer(s)/Soloist(s)/Performing group' is
used for the main artist(s). They are seperated with the "/"
character.</div>
</p>

<p>
<a name="TPE2"> </a>
<div class=h5>TPE2</div>
<div class=t>The 'Band/Orchestra/Accompaniment' frame is used for additional
information about the performers in the recording.</div>
</p>

<p>
<a name="TPE3"> </a>
<div class=h5>TPE3</div>
<div class=t>The 'Conductor' frame is used for the name of the conductor.</div>
</p>

<p>
<a name="TPE4"> </a>
<div class=h5>TPE4</div>
<div class=t>The 'Interpreted, remixed, or otherwise modified by' frame contains
more information about the people behind a remix and similar
interpretations of another existing piece.</div>
</p>

<p>
<a name="TPOS"> </a>
<div class=h5>TPOS</div>
<div class=t>The 'Part of a set' frame is a numeric string that describes which
part of a set the audio came from. This frame is used if the source
described in the "<a href="#TALB">TALB</a>" frame is divided into several mediums, e.g. a
double CD. The value may be extended with a "/" character and a
numeric string containing the total number of parts in the set. E.g.
"1/2".</div>
</p>

<p>
<a name="TPUB"> </a>
<div class=h5>TPUB</div>
<div class=t>The 'Publisher' frame simply contains the name of the label or
publisher.</div>
</p>

<p>
<a name="TRCK"> </a>
<div class=h5>TRCK</div>
<div class=t>The 'Track number/Position in set' frame is a numeric string
containing the order number of the audio-file on its original
recording. This may be extended with a "/" character and a numeric
string containing the total numer of tracks/elements on the original
recording. E.g. "4/9".</div>
</p>

<p>
<a name="TRDA"> </a>
<div class=h5>TRDA</div>
<div class=t>The 'Recording dates' frame is a intended to be used as complement to
the "<a href="#TYER">TYER</a>", "<a href="#TDAT">TDAT</a>" and "<a href="#TIME">TIME</a>" frames. E.g. "4th-7th June, 12th June"
in combination with the "<a href="#TYER">TYER</a>" frame.</div>
</p>

<p>
<a name="TRSN"> </a>
<div class=h5>TRSN</div>
<div class=t>The 'Internet radio station name' frame contains the name of the
internet radio station from which the audio is streamed.</div>
</p>

<p>
<a name="TRSO"> </a>
<div class=h5>TRSO</div>
<div class=t>The 'Internet radio station owner' frame contains the name of the
owner of the internet radio station from which the audio is
streamed.</div>
</p>

<p>
<a name="TSIZ"> </a>
<div class=h5>TSIZ</div>
<div class=t>The 'Size' frame contains the size of the audiofile in bytes,
excluding the ID3v2 tag, represented as a numeric string.</div>
</p>

<p>
<a name="TSRC"> </a>
<div class=h5>TSRC</div>
<div class=t>The 'ISRC' frame should contain the International Standard Recording
Code (<a href="#ISRC">ISRC</a>) (12 characters).</div>
</p>

<p>
<a name="TSSE"> </a>
<div class=h5>TSSE</div>
<div class=t>The 'Software/Hardware and settings used for encoding' frame
includes the used audio encoder and its settings when the file was
encoded. Hardware refers to hardware encoders, not the computer on
which a program was run.</div>
</p>

<p>
<a name="TYER"> </a>
<div class=h5>TYER</div>
<div class=t>The 'Year' frame is a numeric string with a year of the recording.
This frames is always four characters long (until the year 10000).</div>
</p>

<h3>4.2.2.User defined text information frame</h3>
<p class=t>
<div class=t>This frame is intended for one-string text information concerning the
audiofile in a similar way to the other "T"-frames. The frame body
consists of a description of the string, represented as a terminated
string, followed by the actual string. There may be more than one
"TXXX" frame in each tag, but only one with the same description.
</p>
<p><center><table border=0 width="70%">
<tr><td colspan=2>&lt;Header for 'User defined text information frame', ID: "TXXX"&gt;
<tr><td>Text encoding</td><td>$xx</td></tr>
<tr><td>Description</td><td>&lt;text string according to encoding&gt; $00 (00)</td></tr>
<tr><td>Value</td><td>&lt;text string according to encoding&gt;</td></tr>
</table></center></p>

<a name="sec4.3"> </a>
<h3>4.3.URL link frames</h3>
<p class=t>
With these frames dynamic data such as webpages with touring
information, price information or plain ordinary news can be added to
the tag. There may only be one <a href="#URL">URL</a> link frame of its kind in an
tag, except when stated otherwise in the frame description. If the
textstring is followed by a termination ($00 (00)) all the following
information should be ignored and not be displayed. All <a href="#URL">URL</a> link
frame identifiers begins with "W". Only <a href="#URL">URL</a> link frame identifiers
begins with "W". All <a href="#URL">URL</a> link frames have the following format:
</p>
<p><center><table border=0 width="70%">
<tr><td colspan=2>&lt;Header for 'URL link frame', ID: "W000" - "WZZZ", excluding "WXXX" described in 4.3.2.&gt;</td></tr>
<tr><td>URL</td><td width="80%">&lt;text string&gt;</td></tr>
</table></center></p>

<a name="sec4.3.1"> </a>
<h3>4.3.1.URL link frames - details</h3>
<p>
<a name="WCOM"> </a>
<div class=h5>WCOM</div>
<div class=t>The 'Commercial information' frame is a <a href="#URL">URL</a> pointing at a webpage
with information such as where the album can be bought. There may be
more than one "WCOM" frame in a tag, but not with the same content.</div>
</p>

<p>
<a name="WCOP"> </a>
<div class=h5>WCOP</div>
<div class=t>The 'Copyright/Legal information' frame is a <a href="#URL">URL</a> pointing at a
webpage where the terms of use and ownership of the file is
described.</div>
</p>

<p>
<a name="WOAF"> </a>
<div class=h5>WOAF</div>
<div class=t>The 'Official audio file webpage' frame is a <a href="#URL">URL</a> pointing at a file
specific webpage.</div>
</p>

<p>
<a name="WOAR"> </a>
<div class=h5>WOAR</div>
<div class=t>The 'Official artist/performer webpage' frame is a <a href="#URL">URL</a> pointing at
the artists official webpage. There may be more than one "WOAR" frame
in a tag if the audio contains more than one performer, but not with
the same content.</div>
</p>

<p>
<a name="WOAS"> </a>
<div class=h5>WOAS</div>
<div class=t>The 'Official audio source webpage' frame is a <a href="#URL">URL</a> pointing at the
official webpage for the source of the audio file, e.g. a movie.</div>
</p>

<p>
<a name="WORS"> </a>
<div class=h5>WORS</div>
<div class=t>The 'Official internet radio station homepage' contains a <a href="#URL">URL</a>
pointing at the homepage of the internet radio station.</div>
</p>

<p>
<a name="WPAY"> </a>
<div class=h5>WPAY</div>
<div class=t>The 'Payment' frame is a <a href="#URL">URL</a> pointing at a webpage that will handle
the process of paying for this file.</div>
</p>

<p>
<a name="WPUB"> </a>
<div class=h5>WPUB</div>
<div class=t>The 'Publishers official webpage' frame is a <a href="#URL">URL</a> pointing at the
official wepage for the publisher.</div>
</p>

<a name="sec4.3.2"> </a>
<h3>4.3.2.User defined URL link frame</h3>
<p class=t>
This frame is intended for <a href="#URL">URL</a> links concerning the audiofile
in a similar way to the other "W"-frames. The frame body consists
of a description of the string, represented as a terminated string,
followed by the actual <a href="#URL">URL</a>. The <a href="#URL">URL</a> is always encoded with <a href="#ISO-8859-1">ISO-8859-1</a>. There may be more than one "WXXX" frame in each tag,
but only one with the same description.
</p>
<p><center><table border=0 width="70%">
<tr><td colspan=2> &lt;Header for 'User defined URL link frame', ID: "WXXX"&gt;</td></tr>
<tr><td>Text encoding</td><td width="80%">$xx</td></tr>
<tr><td>Description </td><td>&lt;text string according to encoding&gt; $00 (00)</td></tr>
<tr><td>URL </td><td>&lt;text string&gt;</td></tr>
</table></center></p>

<a name="sec4.4"> </a>
<h3>4.4.Involved people list</h3>
<p class=t>
Since there might be a lot of people contributing to an audio file in
various ways, such as musicians and technicians, the 'Text
information frames' are often insufficient to list everyone involved
in a project. The 'Involved people list' is a frame containing the
names of those involved, and how they were involved. The body simply
contains a terminated string with the involvement directly followed
by a terminated string with the involvee followed by a new
involvement and so on. There may only be one "IPLS" frame in each
tag.
</p>
<p><center><table border=0 width="70%">
<tr><td colspan=2> &lt;Header for 'Involved people list', ID: "IPLS"&gt;</td></tr>
<tr><td>Text encoding</td><td width="80%">$xx</td></tr>
<tr><td>People list strings</td><td>&lt;text strings according to encoding&gt;</td></tr>
</table></center></p>

<a name="sec4.5"> </a>
<h3>4.5.Music CD identifier</h3>
<p class=t>
This frame is intended for music that comes from a CD, so that the CD
can be identified in databases such as the <a href="#CDDB">CDDB</a>. The frame
consists of a binary dump of the Table Of Contents, TOC, from the CD,
which is a header of 4 bytes and then 8 bytes/track on the CD plus 8
bytes for the 'lead out' making a maximum of 804 bytes. The offset to
the beginning of every track on the CD should be described with a
four bytes absolute CD-frame address per track, and not with absolute
time. This frame requires a present and valid "<a href="#TRCK">TRCK</a>" frame, even if
the CD's only got one track. There may only be one "MCDI" frame in
each tag.
</p>
<p><center><table border=0 width="70%">
<tr><td colspan=2> &lt;Header for 'Music CD identifier', ID: "MCDI"&gt;</td></tr>
<tr><td>CD TOC</td><td>&lt;binary data&gt;</td></tr>
</table></center></p>

<a name="sec4.6"> </a>
<h3>4.6.Event timing codes</h3>
<p class=t>
This frame allows synchronisation with key events in a song or sound.
The header is:
</p><p><center><table border=0 width="70%">
<tr><td colspan=2> &lt;Header for 'Event timing codes', ID: "ETCO"&gt;</td></tr>
<tr><td>Time stamp format</td><td width="80%">$xx</td></tr>
</table></center>
</p><p class=t>
Where time stamp format is:
</p><p class=ind>
 $01 Absolute time, 32 bit sized, using <a href="#MPEG">MPEG</a> frames as unit<br>
 $02 Absolute time, 32 bit sized, using milliseconds as unit
</p><p class=t>
Abolute time means that every stamp contains the time from the
beginning of the file.
</p><p class=t>
Followed by a list of key events in the following format:
</p><p><center><table border=0 width="70%">
<tr><td>Type of event</td><td width="80%">$xx</td></tr>
<tr><td>Time stamp</td><td>$xx (xx ...)</td></tr>
</table></center>
</p><p class=t>
The 'Time stamp' is set to zero if directly at the beginning of the
sound or after the previous event. All events should be sorted in
chronological order. The type of event is as follows:
</p><p><center><table border=0 width="70%">
<tr><td>$00</td><td width="80%">padding (has no meaning)</td></tr>
<tr><td>$01</td><td>end of initial silence</td></tr>
<tr><td>$02</td><td>intro start</td></tr>
<tr><td>$03</td><td>mainpart start</td></tr>
<tr><td>$04</td><td>outro start</td></tr>
<tr><td>$05</td><td>outro end</td></tr>
<tr><td>$06</td><td>verse start</td></tr>
<tr><td>$07</td><td>refrain start</td></tr>
<tr><td>$08</td><td>interlude start</td></tr>
<tr><td>$09</td><td>theme start</td></tr>
<tr><td>$0A</td><td>variation start</td></tr>
<tr><td>$0B</td><td>key change</td></tr>
<tr><td>$0C</td><td>time change</td></tr>
<tr><td>$0D</td><td>momentary unwanted noise (Snap, Crackle & Pop)</td></tr>
<tr><td>$0E</td><td>sustained noise</td></tr>
<tr><td>$0F</td><td>sustained noise end</td></tr>
<tr><td>$10</td><td>intro end</td></tr>
<tr><td>$11</td><td>mainpart end</td></tr>
<tr><td>$12</td><td>verse end</td></tr>
<tr><td>$13</td><td>refrain end</td></tr>
<tr><td>$14</td><td>theme end</td></tr>

<tr><td>$15-$DF</td><td>reserved for future use</td></tr>

<tr><td>$E0-$EF</td><td>not predefined sync 0-F</td></tr>

<tr><td>$F0-$FC</td><td>reserved for future use</td></tr>

<tr><td>$FD</td><td>audio end (start of silence)</td></tr>
<tr><td>$FE</td><td>audio file ends</td></tr>
<tr><td>$FF</td><td>one more byte of events follows (all the following bytes with the value $FF have the same function)</td></tr>
</table></center>
</p><p class=t>
Terminating the start events such as "intro start" is not required.
The 'Not predefined sync's ($E0-EF) are for user events. You might
want to synchronise your music to something, like setting of an
explosion on-stage, turning on your screensaver etc.
</p>
<p class=t>There may only be one "ETCO" frame in each tag.</p>

<a name="sec4.7"> </a>
<h3>4.7.MPEG location lookup table</h3>
<p class=t>
To increase performance and accuracy of jumps within a <a href="#MPEG">MPEG</a>
audio file, frames with timecodes in different locations in the file
might be useful. The ID3v2 frame includes references that the
software can use to calculate positions in the file. After the frame
header is a descriptor of how much the 'frame counter' should
increase for every reference. If this value is two then the first
reference points out the second frame, the 2nd reference the 4th
frame, the 3rd reference the 6th frame etc. In a similar way the
'bytes between reference' and 'milliseconds between reference' points
out bytes and milliseconds respectively.
</p><p class=t>
Each reference consists of two parts; a certain number of bits, as
defined in 'bits for bytes deviation', that describes the difference
between what is said in 'bytes between reference' and the reality and
a certain number of bits, as defined in 'bits for milliseconds
deviation', that describes the difference between what is said in
'milliseconds between reference' and the reality. The number of bits
in every reference, i.e. 'bits for bytes deviation'+'bits for
milliseconds deviation', must be a multiple of four. There may only
be one "MLLT" frame in each tag.
</p><p><center><table border=0 width="70%">
<tr><td colspan=2> &lt;Header for 'Location lookup table', ID: "MLLT"&gt;</td></tr>
<tr><td nowrap>MPEG frames between reference</td><td width="80%">$xx xx</td></tr>
<tr><td>Bytes between reference</td><td>$xx xx xx</td></tr>
<tr><td>Milliseconds between reference</td><td>$xx xx xx</td></tr>
<tr><td>Bits for bytes deviation</td><td>$xx</td></tr>
<tr><td>Bits for milliseconds dev.</td><td>$xx</td></tr>
</table></center>
</p><p class=t>
Then for every reference the following data is included;
</p><p><center><table border=0 width="70%">
<tr><td>Deviation in bytes</td><td width="80%">%xxx....</td></tr>
<tr><td>Deviation in milliseconds</td><td>%xxx....</td></tr>
</table></center>
</p>

<a name="sec4.8"> </a>
<h3>4.8.Synchronised tempo codes</h3>
<p class=t>
For a more accurate description of the tempo of a musical piece this
frame might be used. After the header follows one byte describing
which time stamp format should be used. Then follows one or more
tempo codes. Each tempo code consists of one tempo part and one time
part. The tempo is in BPM described with one or two bytes. If the
first byte has the value $FF, one more byte follows, which is added
to the first giving a range from 2 - 510 BPM, since $00 and $01 is
reserved. $00 is used to describe a beat-free time period, which is
not the same as a music-free time period. $01 is used to indicate one
single beat-stroke followed by a beat-free period.
</p><p class=t>
The tempo descriptor is followed by a time stamp. Every time the
tempo in the music changes, a tempo descriptor may indicate this for
the player. All tempo descriptors should be sorted in chronological
order. The first beat-stroke in a time-period is at the same time as
the beat description occurs. There may only be one "SYTC" frame in
each tag.
</p><p><center><table border=0 width="70%">
<tr><td colspan=2> &lt;Header for 'Synchronised tempo codes', ID: "SYTC"&gt;</td></tr>
<tr><td>Time stamp format</td><td width="80%">$xx</td></tr>
<tr><td>Tempo data </td><td>&lt;binary data&gt;</td></tr>
</table></center>
</p><p class=t>
Where time stamp format is:
</p><p class=ind>
 $01 Absolute time, 32 bit sized, using <a href="#MPEG">MPEG</a> frames as unit<br>
 $02 Absolute time, 32 bit sized, using milliseconds as unit
</p><p class=t>
Abolute time means that every stamp contains the time from the
beginning of the file.
</p>

<a name="sec4.9"> </a>
<h3>4.9.Unsychronised lyrics/text transcription</h3>
<p class=t>
This frame contains the lyrics of the song or a text transcription of
other vocal activities. The head includes an encoding descriptor and
a content descriptor. The body consists of the actual text. The
'Content descriptor' is a terminated string. If no descriptor is
entered, 'Content descriptor' is $00 (00) only. Newline characters
are allowed in the text. There may be more than one 'Unsynchronised
lyrics/text transcription' frame in each tag, but only one with the
same language and content descriptor.
</p><p><center><table border=0 width="70%">
<tr><td colspan=2>&lt;Header for 'Unsynchronised lyrics/text transcription', ID: "USLT"&gt;</td></tr>
<tr><td>Text encoding</td><td width="80%">$xx</td></tr>
<tr><td>Language</td><td>$xx xx xx</td></tr>
<tr><td>Content descriptor</td><td>&lt;text string according to encoding&gt; $00 (00)</td></tr>
<tr><td>Lyrics/text</td><td>&lt;full text string according to encoding&gt;</td></tr>
</table></center>
</p>

<a name="sec4.10"> </a>
<h3>4.10.Synchronised lyrics/text</h3>
<p class=t>
This is another way of incorporating the words, said or sung lyrics,
in the audio file as text, this time, however, in sync with the
audio. It might also be used to describing events e.g. occurring on a
stage or on the screen in sync with the audio. The header includes a
content descriptor, represented with as terminated textstring. If no
descriptor is entered, 'Content descriptor' is $00 (00) only.
</p><p><center><table border=0 width="70%">
<tr><td colspan=2>&lt;Header for 'Synchronised lyrics/text', ID: "SYLT"&gt;</td></tr>
<tr><td>Text encoding</td><td width="80%">$xx</td></tr>
<tr><td>Language</td><td>$xx xx xx</td></tr>
<tr><td>Time stamp format</td><td>$xx</td></tr>
<tr><td>Content type</td><td>$xx</td></tr>
<tr><td>Content descriptor</td><td>&lt;text string according to encoding&gt; $00 (00)</td></tr>
</table></center>
</p>
<p><center><table border=0 width="70%">
<tr><td rowspan=2 valign=top>Encoding:</td><td>$00</td><td><a href="#ISO-8859-1">ISO-8859-1</a> character set is used => $00
 is sync identifier.</td></tr>
<tr><td>$01</td><td><a href="#UNICODE">Unicode</a> character set is used => $00 00 is
 sync identifier.</td></tr>
</table></center></p>

<p><center><table border=0 width="70%">
<tr><td rowspan=7 valign=top>Content type:</td><td>$00</td><td width="80%">is other</td></tr>
<tr><td>$01</td><td>is lyrics</td></tr>
<tr><td>$02</td><td>is text transcription</td></tr>
<tr><td>$03</td><td>is movement/part name (e.g. "Adagio")</td></tr>
<tr><td>$04</td><td>is events (e.g. "Don Quijote enters the stage")</td></tr>
<tr><td>$05</td><td>is chord (e.g. "Bb F Fsus")</td></tr>
<tr><td>$06</td><td>is trivia/'pop up' information</td></tr>
</table></center></p>
<p class=t>
Time stamp format is:
</p><p class=ind>
 $01 Absolute time, 32 bit sized, using <a href="#MPEG">MPEG</a> frames as unit<br>
 $02 Absolute time, 32 bit sized, using milliseconds as unit
</p>
<p class=t>
Abolute time means that every stamp contains the time from the
beginning of the file.
</p><p class=t>
The text that follows the frame header differs from that of the
unsynchronised lyrics/text transcription in one major way. Each
syllable (or whatever size of text is considered to be convenient by
the encoder) is a null terminated string followed by a time stamp
denoting where in the sound file it belongs. Each sync thus has the
following structure:
</p><p><center><table border=0 width="70%">
<tr><td colspan=2>Terminated text to be synced (typically a syllable)</td></tr>
<tr><td nowrap>Sync identifier (terminator to above string)</td><td width="80%">$00 (00)</td></tr>
<tr><td>Time stamp</td><td>$xx (xx ...)</td></tr>
</table></center>
<p class=t>
The 'time stamp' is set to zero or the whole sync is omitted if
located directly at the beginning of the sound. All time stamps
should be sorted in chronological order. The sync can be considered
as a validator of the subsequent string.
</p><p class=t>
Newline ($0A) characters are allowed in all "SYLT" frames and should
be used after every entry (name, event etc.) in a frame with the
content type $03 - $04.
</p><p class=t>
A few considerations regarding whitespace characters: Whitespace
separating words should mark the beginning of a new word, thus
occurring in front of the first syllable of a new word. This is also
valid for new line characters. A syllable followed by a comma should
not be broken apart with a sync (both the syllable and the comma
should be before the sync).</p>
<p class=t>An example: The "USLT" passage</p>
<p class=ind>"Strangers in the night" $0A "Exchanging glances"</p>
<p class=t>would be "SYLT" encoded as:</p>
<p class=ind>
 "Strang" $00 xx xx "ers" $00 xx xx " in" $00 xx xx " the" $00 xx xx
 " night" $00 xx xx 0A "Ex" $00 xx xx "chang" $00 xx xx "ing" $00 xx
 xx "glan" $00 xx xx "ces" $00 xx xx
</p>
<p class=t>There may be more than one "SYLT" frame in each tag, but only one
with the same language and content descriptor.</p>

<a name="sec4.11"> </a>
<h3>4.11.Comments</h3>
<p class=t>
This frame is indended for any kind of full text information that
does not fit in any other frame. It consists of a frame header
followed by encoding, language and content descriptors and is ended
with the actual comment as a text string. Newline characters are
allowed in the comment text string. There may be more than one
comment frame in each tag, but only one with the same language and
content descriptor.
</p><p><center><table border=0 width="70%">
<tr><td colspan=2>&lt;Header for 'Comment', ID: "COMM"&gt;</td></tr>
<tr><td>Text encoding</td><td width="80%">$xx</td></tr>
<tr><td>Language </td><td>$xx xx xx</td></tr>
<tr><td>Short content descrip.</td><td>&lt;text string according to encoding&gt; $00 (00)</td></tr>
<tr><td>The actual text </td><td>&lt;full text string according to encoding&gt;</td></tr>
</table></center>
</p>

<a name="sec4.12"> </a>
<h3>4.12.Relative volume adjustment</h3>
<p class=t>
This is a more subjective function than the previous ones. It allows
the user to say how much he wants to increase/decrease the volume on
each channel while the file is played. The purpose is to be able to
align all files to a reference volume, so that you don't have to
change the volume constantly. This frame may also be used to balance
adjust the audio. If the volume peak levels are known then this could
be described with the 'Peak volume right' and 'Peak volume left'
field. If Peakvolume is not known these fields could be left zeroed
or, if no other data follows, be completely omitted. There may only
be one "RVAD" frame in each tag.
</p><p><center><table border=0 width="70%">
<tr><td colspan=2>&lt;Header for 'Relative volume adjustment', ID: "RVAD"&gt;</td></tr>
<tr><td>Increment/decrement</td><td width="80%">%00xxxxxx</td></tr>
<tr><td>Bits used for volume descr.</td><td>$xx</td></tr>
<tr><td>Relative volume change, right</td><td>$xx xx (xx ...)</td></tr>
<tr><td>Relative volume change, left</td><td>$xx xx (xx ...)</td></tr>
<tr><td>Peak volume right</td><td>$xx xx (xx ...)</td></tr>
<tr><td>Peak volume left</td><td>$xx xx (xx ...)</td></tr>
</table></center></p>
<p class=t>
In the increment/decrement field bit 0 is used to indicate the right
channel and bit 1 is used to indicate the left channel. 1 is
increment and 0 is decrement.
</p><p class=t>
The 'bits used for volume description' field is normally $10 (16
bits) for <a href="#MPEG">MPEG</a> 2 layer I, II and III and MPEG 2.5. This value
may not be $00. The volume is always represented with whole bytes,
padded in the beginning (highest bits) when 'bits used for volume
description' is not a multiple of eight.
</p><p class=t>
This datablock is then optionally followed by a volume definition for
the left and right back channels. If this information is appended to
the frame the first two channels will be treated as front channels.
In the increment/decrement field bit 2 is used to indicate the right
back channel and bit 3 for the left back channel.
</p><p><center><table border=0 width="70%">
<tr><td nowrap>Relative volume change, right back</td><td width="80%">$xx xx (xx ...)</td></tr>
<tr><td>Relative volume change, left back</td><td>$xx xx (xx ...)</td></tr>
<tr><td>Peak volume right back</td><td>$xx xx (xx ...)</td></tr>
<tr><td>Peak volume left back</td><td>$xx xx (xx ...)</td></tr>
</table></center></p>
<p class=t>
If the center channel adjustment is present the following is appended
to the existing frame, after the left and right back channels. The
center channel is represented by bit 4 in the increase/decrease
field.
</p><p><center><table border=0 width="70%">
<tr><td nowrap>Relative volume change, center</td><td width="80%">$xx xx (xx ...)</td></tr>
<tr><td>Peak volume center</td><td>$xx xx (xx ...)</td></tr>
</table></center></p>
<p class=t>
If the bass channel adjustment is present the following is appended
to the existing frame, after the center channel. The bass channel is
represented by bit 5 in the increase/decrease field.
</p><p><center><table border=0 width="70%">
<tr><td nowrap>Relative volume change, bass</td><td width="80%">$xx xx (xx ...)</td></tr>
<tr><td>Peak volume bass</td><td>$xx xx (xx ...)</td></tr>
</table></center></p>

<a name="sec4.13"> </a>
<h3>4.13.Equalisation</h3>
<p class=t>
This is another subjective, alignment frame. It allows the user to
predefine an equalisation curve within the audio file. There may only
be one "EQUA" frame in each tag.
</p><p><center><table border=0 width="70%">
<tr><td colspan=2>&lt;Header of 'Equalisation', ID: "EQUA"&gt;</td></tr>
<tr><td>Adjustment bits</td><td width="80%">$xx</td></tr>
</table></center></p>
<p class=t>
The 'adjustment bits' field defines the number of bits used for
representation of the adjustment. This is normally $10 (16 bits) for
<a href="#MPEG">MPEG</a> 2 layer I, II and III and MPEG 2.5. This value may not be
$00.
</p><p class=t>
This is followed by 2 bytes + ('adjustment bits' rounded up to the
nearest byte) for every equalisation band in the following format,
giving a frequency range of 0 - 32767Hz:
</p><p><center><table border=0 width="70%">
<tr><td>Increment/decrement</td><td width="80%">%x (MSB of the Frequency)</td></tr>
<tr><td>Frequency </td><td>(lower 15 bits)</td></tr>
<tr><td>Adjustment</td><td>$xx (xx ...)</td></tr>
</Table></center></p>
<p class=t>
The increment/decrement bit is 1 for increment and 0 for decrement.
The equalisation bands should be ordered increasingly with reference
to frequency. All frequencies don't have to be declared. The
equalisation curve in the reading software should be interpolated
between the values in this frame. Three equal adjustments for three
subsequent frequencies. A frequency should only be described once in
the frame.
</p>

<a name="sec4.14"> </a>
<h3>4.14.Reverb</h3>
<p class=t>
Yet another subjective one. You may here adjust echoes of different
kinds. Reverb left/right is the delay between every bounce in ms.
Reverb bounces left/right is the number of bounces that should be
made. $FF equals an infinite number of bounces. Feedback is the
amount of volume that should be returned to the next echo bounce. $00
is 0%, $FF is 100%. If this value were $7F, there would be 50% volume
reduction on the first bounce, 50% of that on the second and so on.
Left to left means the sound from the left bounce to be played in the
left speaker, while left to right means sound from the left bounce to
be played in the right speaker.
</p><p class=t>
'Premix left to right' is the amount of left sound to be mixed in the
right before any reverb is applied, where $00 id 0% and $FF is 100%.
'Premix right to left' does the same thing, but right to left.
Setting both premix to $FF would result in a mono output (if the
reverb is applied symmetric). There may only be one "RVRB" frame in
each tag.
</p><p><center><table border=0 width="70%">
<tr><td colspan=2> &lt;Header for 'Reverb', ID: "RVRB"&gt;</td></tr>
<tr><td>Reverb left (ms) </td><td>$xx xx</td></tr>
<tr><td>Reverb right (ms) </td><td>$xx xx</td></tr>
<tr><td>Reverb bounces, left </td><td>$xx</td></tr>
<tr><td>Reverb bounces, right</td><td>$xx</td></tr>
<tr><td>Reverb feedback, left to left </td><td>$xx</td></tr>
<tr><td>Reverb feedback, left to right</td><td>$xx</td></tr>
<tr><td>Reverb feedback, right to right </td><td>$xx</td></tr>
<tr><td>Reverb feedback, right to left</td><td>$xx</td></tr>
<tr><td>Premix left to right </td><td>$xx</td></tr>
<tr><td>Premix right to left </td><td>$xx</td></tr>
</table></center></p>

<a name="sec4.15"> </a>
<h3>4.15.Attached picture</h3>
<p class=t>
This frame contains a picture directly related to the audio file.
Image format is the <a href="#MIME">MIME</a> type and subtype for the image. In
the event that the <a href="#MIME">MIME</a> media type name is omitted, "image/" will be
implied. The "<a href="#PNG">image/png</a>" or "<a href="#JFIF">image/jpeg</a>" picture format
should be used when interoperability is wanted. Description is a
short description of the picture, represented as a terminated
textstring. The description has a maximum length of 64 characters,
but may be empty. There may be several pictures attached to one file,
each in their individual "APIC" frame, but only one with the same
content descriptor. There may only be one picture with the picture
type declared as picture type $01 and $02 respectively. There is the
possibility to put only a link to the image file by using the '<a href="#MIME">MIME</a>
type' "-->" and having a complete <a href="#URL">URL</a> instead of picture data.
The use of linked files should however be used sparingly since there
is the risk of separation of files.
</p><p><center><table border=0 width="70%">
<tr><td colspan=2> &lt;Header for 'Attached picture', ID: "APIC"&gt;</td></tr>
<tr><td>Text encoding</td><td>$xx</td></tr>
<tr><td>MIME type </td><td>&lt;text string&gt; $00</td></tr>
<tr><td>Picture type </td><td>$xx</td></tr>
<tr><td>Description </td><td>&lt;text string according to encoding&gt; $00 (00)</td></tr>
<tr><td>Picture data </td><td>&lt;binary data&gt;</td></tr>
</table>
</center></p>
<p><center><table border=0 width="70%">
<tr><td rowspan=21 valign=top>Picture type:</td><td>$00</td><td>Other</td></tr>
<tr><td>$01</td><td>32x32 pixels 'file icon' (PNG only)</td></tr>
<tr><td>$02</td><td>Other file icon</td></tr>
<tr><td>$03</td><td>Cover (front)</td></tr>
<tr><td>$04</td><td>Cover (back)</td></tr>
<tr><td>$05</td><td>Leaflet page</td></tr>
<tr><td>$06</td><td>Media (e.g. lable side of CD)</td></tr>
<tr><td>$07</td><td>Lead artist/lead performer/soloist</td></tr>
<tr><td>$08</td><td>Artist/performer</td></tr>
<tr><td>$09</td><td>Conductor</td></tr>
<tr><td>$0A</td><td>Band/Orchestra</td></tr>
<tr><td>$0B</td><td>Composer</td></tr>
<tr><td>$0C</td><td>Lyricist/text writer</td></tr>
<tr><td>$0D</td><td>Recording Location</td></tr>
<tr><td>$0E</td><td>During recording</td></tr>
<tr><td>$0F</td><td>During performance</td></tr>
<tr><td>$10</td><td>Movie/video screen capture</td></tr>
<tr><td>$11</td><td>A bright coloured fish</td></tr>
<tr><td>$12</td><td>Illustration</td></tr>
<tr><td>$13</td><td>Band/artist logotype</td></tr>
<tr><td>$14</td><td>Publisher/Studio logotype</td></tr>
</table></center></p>

<a name="sec4.16"> </a>
<h3>4.16.General encapsulated object</h3>
<p class=t>
In this frame any type of file can be encapsulated. After the header,
'Frame size' and 'Encoding' follows '<a href="#MIME">MIME</a> type' represented as
as a terminated string encoded with <a href="#ISO-8859-1">ISO-8859-1</a>. The
filename is case sensitive and is encoded as 'Encoding'. Then follows
a content description as terminated string, encoded as 'Encoding'.
The last thing in the frame is the actual object. The first two
strings may be omitted, leaving only their terminations. There may be more than one "GEOB"
frame in each tag, but only one with the same content descriptor.
</p><p><center><table border=0 width="70%">
<tr><td colspan=2> &lt;Header for 'General encapsulated object', ID: "GEOB"&gt;</td></tr>
<tr><td>Text encoding </td><td>$xx</td></tr>
<tr><td>MIME type </td><td>&lt;text string&gt; $00</td></tr>
<tr><td>Filename</td><td>&lt;text string according to encoding&gt; $00 (00)</td></tr>
<tr><td>Content description </td><td><text string according to encding> $00 (00)</td></tr>
<tr><td>Encapsulated object </td><td>&lt;binary data&gt;</td></tr>
</table></center></p>

<a name="sec4.17"> </a>
<h3>4.17.Play counter</h3>
<p class=t>
This is simply a counter of the number of times a file has been
played. The value is increased by one every time the file begins to
play. There may only be one "PCNT" frame in each tag. When the
counter reaches all one's, one byte is inserted in front of the
counter thus making the counter eight bits bigger. The counter must
be at least 32-bits long to begin with.
</p><p><center><table border=0 width="70%">
<tr><td colspan=2> &lt;Header for 'Play counter', ID: "PCNT"&gt;</td></tr>
<tr><td>Counter </td><td>$xx xx xx xx (xx ...)</td></tr>
</table></center></p>


<a name="sec4.18"> </a>
<h3>4.18.Popularimeter</h3>
<p class=t>
The purpose of this frame is to specify how good an audio file is.
Many interesting applications could be found to this frame such as a
playlist that features better audiofiles more often than others or it
could be used to profile a person's taste and find other 'good' files
by comparing people's profiles. The frame is very simple. It contains
the email address to the user, one rating byte and a four byte play
counter, intended to be increased with one for every time the file is
played. The email is a terminated string. The rating is 1-255 where
1 is worst and 255 is best. 0 is unknown. If no personal counter is
wanted it may be omitted. When the counter reaches all one's, one
byte is inserted in front of the counter thus making the counter
eight bits bigger in the same away as the play counter ("PCNT").
There may be more than one "POPM" frame in each tag, but only one
with the same email address.
</p><p><center><table border=0 width="70%">
<tr><td colspan=2> &lt;Header for 'Popularimeter', ID: "POPM"&gt;</td></tr>
<tr><td>Email to user</td><td>&lt;text string&gt; $00</td></tr>
<tr><td>Rating </td><td>$xx</td></tr>
<tr><td>Counter</td><td>$xx xx xx xx (xx ...)</td></tr>
</table></center></p>

<a name="sec4.19"> </a>
<h3>4.19.Recommended buffer size</h3>
<p class=t>
Sometimes the server from which a audio file is streamed is aware of
transmission or coding problems resulting in interruptions in the
audio stream. In these cases, the size of the buffer can be
recommended by the server using this frame. If the 'embedded info
flag' is true (1) then this indicates that an ID3 tag with the
maximum size described in 'Buffer size' may occur in the audiostream.
In such case the tag should reside between two <a href="#MPEG">MPEG</a> frames, if
the audio is <a href="#MPEG">MPEG</a> encoded. If the position of the next tag is known,
'offset to next tag' may be used. The offset is calculated from the
end of tag in which this frame resides to the first byte of the
header in the next. This field may be omitted. Embedded tags are
generally not recommended since this could render unpredictable
behaviour from present software/hardware.
</p><p class=t>
For applications like streaming audio it might be an idea to embed
tags into the audio stream though. If the clients connects to
individual connections like HTTP and there is a possibility to begin
every transmission with a tag, then this tag should include a
'recommended buffer size' frame. If the client is connected to a
arbitrary point in the stream, such as radio or multicast, then the
'recommended buffer size' frame should be included in every tag.
Every tag that is picked up after the initial/first tag is to be
considered as an update of the previous one. E.g. if there is a
"<a href="#TIT2">TIT2</a>" frame in the first received tag and one in the second tag,
then the first should be 'replaced' with the second.
</p><p class=t>
The 'Buffer size' should be kept to a minimum. There may only be one
"RBUF" frame in each tag.
</p><p><center><table border=0 width="70%">
<tr><td colspan=2>&lt;Header for 'Recommended buffer size', ID: "RBUF"&gt;</td></tr>
<tr><td>Buffer size</td><td>$xx xx xx</td></tr>
<tr><td>Embedded info flag</td><td>%0000000x</td></tr>
<tr><td>Offset to next tag</td><td>$xx xx xx xx</td></tr>
</table></center></p>

<a name="sec4.20"> </a>
<h3>4.20.Audio encryption</h3>
<p class=t>
This frame indicates if the actual audio stream is encrypted, and by
whom. Since standardisation of such encrypion scheme is beyond this
document, all "AENC" frames begin with a terminated string with a
URL containing an email address, or a link to a location where an
email address can be found, that belongs to the organisation
responsible for this specific encrypted audio file. Questions
regarding the encrypted audio should be sent to the email address
specified. If a $00 is found directly after the 'Frame size' and the
audiofile indeed is encrypted, the whole file may be considered
useless.
</p><p class=t>
After the 'Owner identifier', a pointer to an unencrypted part of the
audio can be specified. The 'Preview start' and 'Preview length' is
described in frames. If no part is unencrypted, these fields should
be left zeroed. After the 'preview length' field follows optionally a
datablock required for decryption of the audio. There may be more
than one "AENC" frames in a tag, but only one with the same 'Owner
identifier'.
</p><p><center><table border=0 width="70%">
<tr><td colspan=2>&lt;Header for 'Audio encryption', ID: "AENC"&gt;</td></tr>
<tr><td>Owner identifier</td><td>&lt;text string&gt; $00</td></tr>
<tr><td>Preview start</td><td>$xx xx</td></tr>
<tr><td>Preview length</td><td>$xx xx</td></tr>
<tr><td>Encryption info</td><td>&lt;binary data&gt;</td></tr>
</table></center></p>

<a name="sec4.21"> </a>
<h3>4.21.Linked information</h3>
<p class=t>
To keep space waste as low as possible this frame may be used to link
information from another ID3v2 tag that might reside in another audio
file or alone in a binary file. It is recommended that this method is
only used when the files are stored on a CD-ROM or other
circumstances when the risk of file seperation is low. The frame
contains a frame identifier, which is the frame that should be linked
into this tag, a <a href="#URL">URL</a> field, where a reference to the file where
the frame is given, and additional ID data, if needed. Data should be
retrieved from the first tag found in the file to which this link
points. There may be more than one "LINK" frame in a tag, but only
one with the same contents. A linked frame is to be considered as
part of the tag and has the same restrictions as if it was a physical
part of the tag (i.e. only one "RVRB" frame allowed, whether it's
linked or not).
</p><p><center><table border=0 width="70%">
<tr><td>&lt;Header for 'Linked information', ID: "LINK"&gt;</td></tr>
<tr><td>Frame identifier</td><td>$xx xx xx</td></tr>
<tr><td>URL</td><td>&lt;text string&gt; $00</td></tr>
<tr><td>ID and additional data</td><td>&lt;text string(s)&gt;</td></tr>
</table></center></p>
<p class=t>
Frames that may be linked and need no additional data are "IPLS",
"MCID", "ETCO", "MLLT", "SYTC", "RVAD", "EQUA", "RVRB", "RBUF", the
text information frames and the URL link frames.
</p><p class=t>
The "TXXX", "APIC", "GEOB" and "AENC" frames may be linked with
the content descriptor as additional ID data.
</p><p class=t>
The "COMM", "SYLT" and "USLT" frames may be linked with three bytes
of language descriptor directly followed by a content descriptor as
additional ID data.
</p>

<a name="sec4.22"> </a>
<h3>4.22.Position synchronisation frame</h3>
<p class=t>
This frame delivers information to the listener of how far into the
audio stream he picked up; in effect, it states the time offset of
the first frame in the stream. The frame layout is:
</p><p><center><table border=0 width="70%">
<tr><td colspan=2>&lt;Head for 'Position synchronisation', ID: "POSS"&gt;</td></tr>
<tr><td>Time stamp format</td><td>$xx</td></tr>
<tr><td>Position</td><td>$xx (xx ...)</td></tr>
</table></center></p>
<p class=t>
Where time stamp format is:
</p><p class=ind>
$01 Absolute time, 32 bit sized, using <a href="#MPEG">MPEG</a> frames as unit<br>
$02 Absolute time, 32 bit sized, using milliseconds as unit
</p><p class=t>
and position is where in the audio the listener starts to receive,
i.e. the beginning of the next frame. If this frame is used in the
beginning of a file the value is always 0. There may only be one
"POSS" frame in each tag.
</p>

<a name="sec4.23"> </a>
<h3>4.23.Terms of use frame</h3>
<p class=t>
This frame contains a brief description of the terms of use and
ownership of the file. More detailed information concerning the legal
terms might be available through the "WCOP" frame. Newlines are
allowed in the text. There may only be one "USER" frame in a tag.
</p><p><center><table border=0 width="70%">
<tr><td colspan=2>&lt;Header for 'Terms of use frame', ID: "USER"&gt;</td></tr>
<tr><td>Text encoding</td><td>$xx</td></tr>
<tr><td>Language</td><td>$xx xx xx</td></tr>
<tr><td>The actual text</td><td>&lt;text string according to encoding&gt;</td></tr>
</table></center></p>

<a name="sec4.24"> </a>
<h3>4.24.Ownership frame</h3>
<p class=t>
The ownership frame might be used as a reminder of a made transaction
or, if signed, as proof. Note that the "USER" and "TOWN" frames are
good to use in conjunction with this one. The frame begins, after the
frame ID, size and encoding fields, with a 'price payed' field. The
first three characters of this field contains the currency used for
the transaction, encoded according to <a href="#ISO-4217">ISO-4217</a> alphabetic
currency code. Concatenated to this is the actual price payed, as a
numerical string using "." as the decimal separator. Next is an 8
character date string (YYYYMMDD) followed by a string with the name
of the seller as the last field in the frame. There may only be one
"OWNE" frame in a tag.
</p><p><center><table border=0 width="70%">
<tr><td>&lt;Header for 'Ownership frame', ID: "OWNE"&gt;</td></tr>
<tr><td>Text encoding</td><td>$xx</td></tr>
<tr><td>Price payed</td><td>&lt;text string&gt; $00</td></tr>
<tr><td>Date of purch.</td><td>&lt;text string&gt;</td></tr>
<tr><td>Seller</td><td>&lt;text string according to encoding&gt;</td></tr>
</table></center></p>

<a name="sec4.25"> </a>
<h3>4.25.Commercial frame</h3>
<p class=t>
This frame enables several competing offers in the same tag by
bundling all needed information. That makes this frame rather complex
but it's an easier solution than if one tries to achieve the same
result with several frames. The frame begins, after the frame ID,
size and encoding fields, with a price string field. A price is
constructed by one three character currency code, encoded according
to <a href="#ISO-4217">ISO-4217</a> alphabetic currency code, followed by a
numerical value where "." is used as decimal seperator. In the price
string several prices may be concatenated, seperated by a "/"
character, but there may only be one currency of each type.
</p><p class=t>
The price string is followed by an 8 character date string in the
format YYYYMMDD, describing for how long the price is valid. After
that is a contact <a href="#URL">URL</a>, with which the user can contact the seller,
followed by a one byte 'received as' field. It describes how the
audio is delivered when bought according to the following list:
</p><p><center><table border=0 width="70%">
<tr><td>$00</td><td>Other</td></tr>
<tr><td>$01</td><td>Standard CD album with other songs</td></tr>
<tr><td>$02</td><td>Compressed audio on CD</td></tr>
<tr><td>$03</td><td>File over the Internet</td></tr>
<tr><td>$04</td><td>Stream over the Internet</td></tr>
<tr><td>$05</td><td>As note sheets</td></tr>
<tr><td>$06</td><td>As note sheets in a book with other sheets</td></tr>
<tr><td>$07</td><td>Music on other media</td></tr>
<tr><td>$08</td><td>Non-musical merchandise</td></tr>
</table></center></p>
<p class=t>
Next follows a terminated string with the name of the seller followed
by a terminated string with a short description of the product. The
last thing is the ability to include a company logotype. The first of
them is the 'Picture MIME type' field containing information about
which picture format is used. In the event that the <a href="#MIME">MIME</a> media type
name is omitted, "image/" will be implied. Currently only "<a href="#PNG">image/png</a>"
and "<a href="#JFIF">image/jpeg</a>" are allowed. This format string is followed by the
binary picture data. This two last fields may be omitted if no
picture is to attach.
</p><p><center><table border=0 width="70%">
<tr><td colspan=2> &lt;Header for 'Commercial frame', ID: "COMR"&gt;</td></tr>
<tr><td>Text encoding</td><td>$xx</td></tr>
<tr><td>Price string</td><td>&lt;text string&gt; $00</td></tr>
<tr><td>Valid until</td><td>&lt;text string&gt;</td></tr>
<tr><td>Contact URL</td><td>&lt;text string&gt; $00</td></tr>
<tr><td>Received as</td><td>$xx</td></tr>
<tr><td>Name of seller</td><td>&lt;text string according to encoding&gt; $00 (00)</td></tr>
<tr><td>Description</td><td>&lt;text string according to encoding&gt; $00 (00)</td></tr>
<tr><td>Picture MIME type</td><td>&lt;string&gt; $00</td></tr>
<tr><td>Seller logo</td><td>&lt;binary data&gt;</td></tr>
</table></center></p>

<a name="sec4.26"> </a>
<h3>4.26.Encryption method registration</h3>
<p class=t>
To identify with which method a frame has been encrypted the
encryption method must be registered in the tag with this frame. The
'Owner identifier' is a null-terminated string with a <a href="#URL">URL</a>
containing an email address, or a link to a location where an email
address can be found, that belongs to the organisation responsible
for this specific encryption method. Questions regarding the
encryption method should be sent to the indicated email address. The
'Method symbol' contains a value that is associated with this method
throughout the whole tag. Values below $80 are reserved. The 'Method
symbol' may optionally be followed by encryption specific data. There
may be several "ENCR" frames in a tag but only one containing the
same symbol and only one containing the same owner identifier. The
method must be used somewhere in the tag. See <a href="#sec3.3.1">section 3.3.1</a>, flag j
for more information.
</p><p><center><table border=0 width="70%">
<tr><td colspan=2>&lt;Header for 'Encryption method registration', ID: "ENCR"&gt;</td></tr>
<tr><td>Owner identifier</td><td width="80%">&lt;text string&gt; $00</td></tr>
<tr><td>Method symbol</td><td>$xx</td></tr>
<tr><td>Encryption data</td><td>&lt;binary data&gt;</td></tr>
</table></center></p>

<a name="sec4.27"> </a>
<h3>4.27.Group identification registration</h3>
<p class=t>
This frame enables grouping of otherwise unrelated frames. This can
be used when some frames are to be signed. To identify which frames
belongs to a set of frames a group identifier must be registered in
the tag with this frame. The 'Owner identifier' is a null-terminated
string with a <a href="#URL">URL</a> containing an email address, or a link to a
location where an email address can be found, that belongs to the
organisation responsible for this grouping. Questions regarding the
grouping should be sent to the indicated email address. The 'Group
symbol' contains a value that associates the frame with this group
throughout the whole tag. Values below $80 are reserved. The 'Group
symbol' may optionally be followed by some group specific data, e.g.
a digital signature. There may be several "GRID" frames in a tag but
only one containing the same symbol and only one containing the same
owner identifier. The group symbol must be used somewhere in the tag.
See <a href="#sec3.3.1">section 3.3.1</a>, flag j for more information.
</p><p><center><table border=0 width="70%">
<tr><td colspan=2>&lt;Header for 'Group ID registration', ID: "GRID"&gt;</td></tr>
<tr><td>Owner identifier</td><td>&lt;text string&gt; $00</td></tr>
<tr><td>Group symbol</td><td width="80%">$xx</td></tr>
<tr><td>Group dependent data</td><td>&lt;binary data&gt;</td></tr>
</table></center></p>

<a name="sec4.28"> </a>
<h3>4.28.Private frame</h3>
<p class=t>
This frame is used to contain information from a software producer
that its program uses and does not fit into the other frames. The
frame consists of an 'Owner identifier' string and the binary data.
The 'Owner identifier' is a null-terminated string with a <a href="#URL">URL</a>
containing an email address, or a link to a location where an email
address can be found, that belongs to the organisation responsible
for the frame. Questions regarding the frame should be sent to the
indicated email address. The tag may contain more than one "PRIV"
frame but only with different contents. It is recommended to keep the
number of "PRIV" frames as low as possible.
</p><p><center><table border=0 width="70%">
<tr><td colspan=2>&lt;Header for 'Private frame', ID: "PRIV"&gt;</td></tr>
<tr><td>Owner identifier</td><td width="80%">&lt;text string&gt; $00</td></tr>
<tr><td>The private data</td><td>&lt;binary data&gt;</td></tr>
</table></center></p>

<a name="sec5"> </a>
<h3>5.The 'unsynchronisation scheme'</h3>
<p class=t>
The only purpose of the 'unsynchronisation scheme' is to make the
ID3v2 tag as compatible as possible with existing software. There is
no use in 'unsynchronising' tags if the file is only to be processed
by new software. Unsynchronisation may only be made with MPEG 2 layer
I, II and III and MPEG 2.5 files.
</p><p class=t>
Whenever a false synchronisation is found within the tag, one zeroed
byte is inserted after the first false synchronisation byte. The
format of a correct sync that should be altered by ID3 encoders is as
follows:
</p><p class=ind>
%11111111 111xxxxx
</p><p class=t>
And should be replaced with:
</p><p class=ind>
%11111111 00000000 111xxxxx
</p><p class=t>
This has the side effect that all $FF 00 combinations have to be
altered, so they won't be affected by the decoding process. Therefore
all the $FF 00 combinations have to be replaced with the $FF 00 00
combination during the unsynchronisation.
</p><p class=t>
To indicate usage of the unsynchronisation, the first bit in 'ID3
flags' should be set. This bit should only be set if the tag
contains a, now corrected, false synchronisation. The bit should
only be clear if the tag does not contain any false synchronisations.
</p><p class=t>
Do bear in mind, that if a compression scheme is used by the encoder,
the unsynchronisation scheme should be applied *afterwards*. When
decoding a compressed, 'unsynchronised' file, the 'unsynchronisation
scheme' should be parsed first, decompression afterwards.
</p><p class=t>
If the last byte in the tag is $FF, and there is a need to eliminate
false synchronisations in the tag, at least one byte of padding
should be added.
</p>

<a name="sec6"> </a>
<h3>6.Copyright</h3>
<p class=t>
Copyright &copy; Martin Nilsson 1998. All Rights Reserved.
</p><p class=t>
This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any
kind, provided that a reference to this document is included on all
such copies and derivative works. However, this document itself may
not be modified in any way and reissued as the original document.
</p><p class=t>
The limited permissions granted above are perpetual and will not be revoked.
</p><p class=t>
This document and the information contained herein is provided on an
"AS IS" basis and THE AUTHORS DISCLAIMS ALL WARRANTIES, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
</p>


<a name="sec7"> </a>
<h3>7.References</h3>

<a name="CDDB"> </a>
<p class=t>[CDDB] Compact Disc Data Base</p>
<p class=ind>&lt;url:<a href="http://www.cddb.com">http://www.cddb.com</a>&gt;</p>

<a name="ID3v2"> </a>
<p class=t>[ID3v2] Martin Nilsson, "ID3v2 informal standard".</p>
<p class=ind>&lt;url:<a href="http://www.id3.org/id3v2-00.txt">http://www.id3.org/id3v2-00.txt</a>&gt;</p>

<a name="ISO-639-2"> </a>
<p class=t>[ISO-639-2] ISO/FDIS 639-2.<br>
Codes for the representation of names of languages, Part 2: Alpha-3 code. Technical committee / subcommittee: TC 37 / SC 2</p>

<a name="ISO-4217"> </a>
<p class=t>[ISO-4217] ISO 4217:1995.<br>
Codes for the representation of currencies and funds. Technical committee / subcommittee: TC 68</p>

<a name="ISO-8859-1"> </a>
<p class=t>[ISO-8859-1] ISO/IEC DIS 8859-1.<br>
8-bit single-byte coded graphic character sets, Part 1: Latin alphabet No. 1. Technical committee / subcommittee: JTC 1 / SC 2</p>

<a name="ISRC"> </a>
<p class=t>[ISRC] ISO 3901:1986<br>
International Standard Recording Code (ISRC). Technical committee / subcommittee: TC 46 / SC 9</p>

<a name="JFIF"> </a>
<p class=t>[JFIF] JPEG File Interchange Format, version 1.02</p>
<p class=ind>&lt;url:<a href="http://www.w3.org/Graphics/JPEG/jfif.txt">http://www.w3.org/Graphics/JPEG/jfif.txt</a>&gt;</p>

<a name="MIME"> </a>
<p class=t>[MIME] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies", RFC 2045, November 1996.</p>
<p class=ind>&lt;url:<a href="ftp://ftp.isi.edu/in-notes/rfc2045.txt">ftp://ftp.isi.edu/in-notes/rfc2045.txt</a>&gt;</p>

<a name="MPEG"> </a>
<p class=t>[MPEG] ISO/IEC 11172-3:1993.<br>
Coding of moving pictures and associated audio for digital storage media at up to about 1,5 Mbit/s, Part 3: Audio. Technical committee / subcommittee: JTC 1 / SC 29<br>
&nbsp;and<br>
ISO/IEC 13818-3:1995<br>
Generic coding of moving pictures and associated audio information, Part 3: Audio. Technical committee / subcommittee: JTC 1 / SC 29<br>
&nbsp;and<br>
ISO/IEC DIS 13818-3<br>
Generic coding of moving pictures and associated audio information, Part 3: Audio (Revision of ISO/IEC 13818-3:1995)</p>

<a name="PNG"> </a>
<p class=t>[PNG] Portable Network Graphics, version 1.0</p>
<p class=ind>&lt;url:<a href="http://www.w3.org/TR/REC-png-multi.html">http://www.w3.org/TR/REC-png-multi.html</a>&gt;</p>

<a name="UNICODE"> </a>
<p class=t>[UNICODE] ISO/IEC 10646-1:1993.<br>
Universal Multiple-Octet Coded Character Set (UCS), Part 1: Architecture and Basic Multilingual Plane. Technical committee / subcommittee: JTC 1 / SC 2</p>
<p class=ind>&lt;url:<a href="http://www.unicode.org">http://www.unicode.org</a>&gt;</p>

<a name="URL"> </a>
<p class=t>[URL] T. Berners-Lee, L. Masinter & M. McCahill, "Uniform Resource Locators (URL).", RFC 1738, December 1994.</p>
<p class=ind>&lt;url:<a href="ftp://ftp.isi.edu/in-notes/rfc1738.txt">ftp://ftp.isi.edu/in-notes/rfc1738.txt</a>&gt;</p>

<a name="ZLIB"> </a>
<p class=t>[ZLIB] P. Deutsch, Aladdin Enterprises & J-L. Gailly, "ZLIB Compressed Data Format Specification version 3.3", RFC 1950, May 1996.</p>
<p class=ind>&lt;url:<a href="ftp://ftp.isi.edu/in-notes/rfc1950.txt">ftp://ftp.isi.edu/in-notes/rfc1950.txt</a>&gt;</p>


<a name="sec8"> </a>
<h3>8.Appendix</h3>

<a name="secA"> </a>
<h3>A.Appendix A - Genre List from ID3v1</h3>
<center><table border=0 width="70%"><tr valign=top><td>
The following genres is defined in ID3v1
<pre>
 0.Blues
 1.Classic Rock
 2.Country
 3.Dance
 4.Disco
 5.Funk
 6.Grunge
 7.Hip-Hop
 8.Jazz
 9.Metal
 10.New Age
 11.Oldies
 12.Other
 13.Pop
 14.R&B
 15.Rap
 16.Reggae
 17.Rock
 18.Techno
 19.Industrial
 20.Alternative
 21.Ska
 22.Death Metal
 23.Pranks
 24.Soundtrack
 25.Euro-Techno
 26.Ambient
 27.Trip-Hop
 28.Vocal
 29.Jazz+Funk
 30.Fusion
 31.Trance
 32.Classical
 33.Instrumental
 34.Acid
 35.House
 36.Game
 37.Sound Clip
 38.Gospel
 39.Noise
 40.AlternRock
 41.Bass
 42.Soul
 43.Punk
 44.Space
 45.Meditative
 46.Instrumental Pop
 47.Instrumental Rock
 48.Ethnic
 49.Gothic
 50.Darkwave
 51.Techno-Industrial
 52.Electronic
 53.Pop-Folk
 54.Eurodance
 55.Dream
 56.Southern Rock
 57.Comedy
 58.Cult
 59.Gangsta
 60.Top 40
 61.Christian Rap
 62.Pop/Funk
 63.Jungle
 64.Native American
 65.Cabaret
 66.New Wave
 67.Psychedelic
 68.Rave
 69.Showtunes
 70.Trailer
 71.Lo-Fi
 72.Tribal
 73.Acid Punk
 74.Acid Jazz
 75.Polka
 76.Retro
 77.Musical
 78.Rock & Roll
 79.Hard Rock
</pre>
</td><td>
The following genres are Winamp extensions
<pre>
 80.Folk
 81.Folk-Rock
 82.National Folk
 83.Swing
 84.Fast Fusion
 85.Bebob
 86.Latin
 87.Revival
 88.Celtic
 89.Bluegrass
 90.Avantgarde
 91.Gothic Rock
 92.Progressive Rock
 93.Psychedelic Rock
 94.Symphonic Rock
 95.Slow Rock
 96.Big Band
 97.Chorus
 98.Easy Listening
 99.Acoustic
100.Humour
101.Speech
102.Chanson
103.Opera
104.Chamber Music
105.Sonata
106.Symphony
107.Booty Bass
108.Primus
109.Porn Groove
110.Satire
111.Slow Jam
112.Club
113.Tango
114.Samba
115.Folklore
116.Ballad
117.Power Ballad
118.Rhythmic Soul
119.Freestyle
120.Duet
121.Punk Rock
122.Drum Solo
123.A capella
124.Euro-House
125.Dance Hall
</pre></td></tr></table></center>

<a name="sec9"> </a>
<h3>9.Author's Address</h3>
<p class=t>
Written by
</p><p class=ind>
Martin Nilsson<br>
Rydsvgen 246 C. 30<br>
S-584 34 Linkping<br>
Sweden<br>
</p><p class=ind>
Email: <a href="mailto:nilsson@id3.org">nilsson@id3.org</a>
</p>

<p class=t>
Edited by
</p><p class=ind>
Dirk Mahoney<br>
57 Pechey Street<br>
Chermside Q<br>
Australia 4032<br>
</p><p class=ind>
Email: <a href="mailto:dirk@id3.org">dirk@id3.org</a>
</p>
<p class=ind>
Johan Sundstrm<br>
Alsttersgatan 5 A. 34<br>
S-584 35 Linkping<br>
Sweden<br>
</p><p class=ind>
Email: <a href="mailto:johan@id3.org">johan@id3.org</a>
</p>

</body></html>