| Informal standard Document: id3v2.4.0-changes.html |
M. Nilsson Latest change: 21st December 2000 |
This document describes the changes between ID3v2.3.0
[ID3v2.3.0] and
ID3v2.4.0 [ID3v2.4.0-strct][ID3v2.4.0-frames]. This document does
not
claim to be complete nor correct.
Distribution of this document is unlimited.
This document outlines the more important differences between
ID3v2.3.0 and ID3v2.4.0. In general ID3v.2.4.0 can be said to be
more
consistent and easier to implement and more suitable to real world
conditions than the previous versions.
References to sections in the ID3v2.4.0 Main Structure
[ID3v2.4.0-strct] document will be given as [S:x.y] where x is the
section and y is the subsection. In a similar fashion references to
sections in the ID3v2.4.0 Native Frames [ID3v2.4.0-frames] document
will be given as [F:x.y].
The location of tags in a file as well as methods to find and
merge
tags are far better defined in ID3v2.4.0 [S:5] than previous
versions. A reverse search for tags are improved by the addition of
a
tag footer [S:3.4]. A tag footer flag has been added to the header
flags to indicate the presence of a ID3v2 footer, hence the size
field is not affected by the footer [S:3.1].
The extended header has been completely rewritten [S:3.2] and
can not
produce false synchs. It is also possible to indicate artificial
tag
restrictions in the extended header, for use with thinner clients.
Unsynchronisation [S:6.1] is done on frame level, instead of on
tag
level, making it easier to skip frames, increasing the
streamability
of the tag. The unsynchronisation flag in the header [S:3.1]
indicates if all frames has been unsynchronized, while the new
unsynchronisation flag in the frame header [S:4.1.2] indicates
unsynchronisation. To avoid false synchronisations in the frame
header the size description and flag field has been rewritten
[S:4].
Resynchronisation of the complete tag when the unsynchronisation
flag
in the tag header is set might result in a corrupt tag.
The character encodings UTF-16BE and UTF-8 has been added to the
list
of valid encodings [S:4].
EQUA - Equalization
This frame is replaced by the EQU2 frame, 'Equalisation (2)'
[F:4.12].
IPLS - Involved people list
This frame is replaced by the two frames TMCL, 'Musician
credits
list' [F:4.2.2], and TIPL, 'Involved people list' [F:4.2.2].
RVAD - Relative volume adjustment
This frame is replaced by the RVA2 frame, 'Relative volume
adjustment (2)' [F:4.11].
TDAT - Date
This frame is replaced by the TDRC frame, 'Recording time'
[F:4.2.5].
TIME - Time
This frame is replaced by the TDRC frame, 'Recording time'
[F:4.2.5].
TORY - Original release year
This frame is replaced by the TDOR frame, 'Original release
time'
[F:4.2.5].
TRDA - Recording dates
This frame is replaced by the TDRC frame, 'Recording time'
[F:4.2.5].
TSIZ - Size
The information contained in this frame is in the general
case
either trivial to calculate for the player or impossible for
the
tagger to calculate. There is however no good use for such
information. The frame is therefore completely deprecated.
TYER - Year
This frame is replaced by the TDRC frame, 'Recording time'
[F:4.2.5].
ASPI Audio seek point index [F:4.30]
EQU2 Equalisation (2) [F:4.12]
RVA2 Relative volume adjustment (2) [F:4.11]
SEEK Seek frame [F:4.29]
SIGN Signature frame [F:4.28]
TDEN Encoding time [F:4.2.5]
TDOR Original release time [F:4.2.5]
TDRC Recording time [F:4.2.5]
TDRL Release time [F:4.2.5]
TDTG Tagging time [F:4.2.5]
TIPL Involved people list [F:4.2.2]
TMCL Musician credits list [F:4.2.2]
TMOO Mood [F:4.2.3]
TPRO Produced notice [F:4.2.4]
TSOA Album sort order [F:4.2.5]
TSOP Performer sort order [F:4.2.5]
TSOT Title sort order [F:4.2.5]
TSST Set subtitle [F:4.2.1]
[ID3v2.3.0] Martin Nilsson, "ID3v2
informal standard".
<url:http://www.id3.org/id3v2.3.0.txt>
[ID3v2-frames] Martin Nilsson,
"ID3 tag version 2.4.0 - Native Frames"
<url:http//www.id3.org/id3v2.4.0-frames.txt>
[ID3v2-strct] Martin Nilsson,
"ID3 tag version 2.4.0 - Main
Structure"
<url:http//www.id3.org/id3v2.4.0-structure.txt>