ID3 Reader

This library was originally made by Jacob Seidelin using ID3v1 for demo'ing his BinaryAjax library. [http://www.nihilogic.dk/labs/id3/]
It was then extended by me to include the ID3v2 tag specification [http://www.id3.org/id3v2.4.0-structure], while I was working at Opera Software, in the context of the Unite Media Player application which was developed using server side JavaScript.

Source Code

Repository

Demo

Click to read the ID3 info from the following music files:
Use your own local files:
You can also drag your local files here if it's supported by your browser

Artist
Title
Album
Year
Comment
Genre
Track
Lyrics
Cover Art

Technical Information

This library will only download the relevant data from the mp3 file whenever the webserver supports the HTTP Range feature, otherwise the entire file will be downloaded at the cost of degrading the performance of the library. This library is not complete and there is still some features missing and/or going on:

Unsynchronisation support
CommonJS support
Support for other types of charsets, at the moment only latin1, UTF-8 and UTF-16 are supported, these are the ones defined in the specification. However, the usage of local charsets has been common for a long time specially in Russia, Japan and China. This support can be achieved using jschardet and a proper string reader function.
Opera support, as soon as Opera supports "charset=x-user-defined" on XHR requests.

How To Use It

In its simplest form:

ID3.loadTags("filename.mp3", function() {
    var tags = ID3.getAllTags(filename);
    alert(tags.artist + " - " + tags.title + ", " + tags.album);
});

by specifying specific tags:

ID3.loadTags("filename.mp3", function() {
    var tags = ID3.getAllTags(filename);
    alert(tags.COMM.data + " - " + tags.TCON.data + ", " + tags.WXXX.data);
},
{tags: ["COMM", "TCON", "WXXX"]});

or even by specifying shortcuts instead of cryptic tags:

ID3.loadTags("filename.mp3", function() {
    var tags = ID3.getAllTags(filename);
    alert(tags.comment + " - " + tags.track + ", " + tags.lyrics);
},
{tags: ["comment", "track", "lyrics"]});

Documentation

ID3.loadTags(url, cb, [options])

url - The URL of the mp3 file to read, this must reside on the same domain (document.domain).
cb - The callback function to invoke when the tags are loaded.
options - Optional parameters.
options.tags - The array of tags and/or shortcuts to read from the ID3 block. Default value is: ["title", "artist", "album", "track"]
options.dataReader - The function used to create the data reader out of a url. It receives (url, success: callback function that returns the data reader, fail: callback function to inform an error setting up the reader). By default it will be BufferedBinaryAjax.

ID3.getAllTags(url)

url - The URL of the mp3 file to read, this must be the same value given to ID3.loadTags().

return value - This function will return the following object structure, for IDv1:

{
    version: "1.1",
    title: string,
    artist: string,
    album: string,
    year: string,
    comment: string,
    track: string,
    genre: string
}

and for ID3v2:

{
    version: "2.<major>.<revision>",
    major: integer,
    revision: integer,
    flags: {
        unsynchronisation: boolean,
        extended_header: boolean,
        experimental_indicator: boolean
    },
    size: integer,
    <frame id>*: {
        id: integer,
        size: integer,
        description: string,
        data: <frame structure>
    },
    <shortcut>*: pointer to <frame id>.data
}

Currently supported frames:

APIC/PIC: Attached picture
COMM/COM: Comments
PCNT/CNT: Play counter
T*: Text frames
USLT/ULT: Unsychronized lyric/text transcription

Shortcuts:

title: TIT2/TT2
artist: TPE1/TP1
album: TALB/TAL
year: TYER/TYE
comment: COMM/COM
track: TRCK/TRK
genre: TCON/TCO
picture: APIC/PIC
lyrics: USLT/ULT

A comprehensive list of all tags defined in the specification can be found here: http://www.id3.org/id3v2.3.0#head-e4b3c63f836c3eb26a39be082065c21fba4e0acc