Using the ID3 extension you might be interested in some more functionality for working with MP3-files that is missing in the PHP C-modules.
Such as extracting for instance the first 10 seconds of a song, merging MP3 files, calculating the exact length of the MP3 file.
The following class in pure PHP is available for that:
http://www.sourcerally.net/Scripts/20-PHP-MP3-Class
XLVI. ID3 Functions
Introduction
These functions let you read and manipulate ID3 tags. ID3 tags are used in MP3 files to store title of the song, as well as information about the artist, album, genre, year and track number.
Requirements
No external libraries are needed to build this extension.
Installation
id3 is part of PECL and can be installed using the PEAR installer. To compile PHP with id3 support, downloadthe sourcecode, put it in php-src/ext/id3 and compile PHP using --enable-id3.
Runtime Configuration
This extension has no configuration directives defined in php.ini.
Resource Types
This extension has no resource types defined.
Predefined Constants
Most of the id3 functions either let you specify or return a tag version. In order to specify the version please use on of these constants.
- ID3_V1_0 (integer)
ID3_V1_0 is used if you are working with ID3 V1.0 tags. These tags may contain the fields title, artist, album, genre, year and comment.
- ID3_V1_1 (integer)
ID3_V1_1 is used if you are working with ID3 V1.1 tags. These tags may all information contained in v1.0 tags plus the track number.
- ID3_V2 (integer)
ID3_V2 is used if you are working with ID3 V2.x tags. These tags are quite flexible and are currently not supported by the id3 extension.
- İçindekiler
- id3_get_genre_id -- Get the id for a genre.
- id3_get_genre_list -- Get all possible genre values.
- id3_get_genre_name -- Get the name for a genre id.
- id3_get_tag -- Get all information stored in an ID3 tag
- id3_get_version -- Get version of an ID3 tag
- id3_remove_tag -- Remove an existing ID3 tag
- id3_set_tag -- Update information stored in an ID3 tag
ID3 Functions
29-Dec-2006 06:54
15-Nov-2006 11:58
Windows XP users may be having trouble with routines provided here and may (as above) only have access to "read" classes. The following very simplified "write" can be used for replacing Windows Media Player file tags, and with care and adjustments, can be used more generally.
<?php
define(_Title,"TIT2");
define(_Artist,"TPE1");
define(_Group,"TPE2");
define(_Album,"TALB");
define(_Genre,"TCON");
define(_TrackNo,"TRCK");
define(_Year,"TYER");
$frames = array(_Album=>"The Ultimate Experience",
_TrackNo=>"1",
_Title=>"All along the watchtower",
_Artist=>"Jimi Hendrix",
_Group=>"",
_Year=>"19xx",
_Genre=>"Rock");
#..........................................
# WRITE ID3 TAGS (Write MP3 [v1, v2]
#..........................................
function writeTags($mp3) {
$fl = file_get_contents($mp3);
$Header = substr($fl,0,10);
$tagLen = calcDecTagLen(substr($Header,6,4),$tagLen);
$music = substr($fl,$tagLen+10,-128);
# Can use input Header for output but you may
# wish to change the output filename for testing
$tagLen = 1024; # or whatever you like >your actual
$Header = substr($Header,0,6).setHexTagLen($tagLen);
file_put_contents($mp3,mkV2Tag($Header,$tagLen).$music.mkV1Tag());
}
# Create the V2 tag
function mkV2Tag($Hdr,$tagLen) {
Global $frames;
$null = chr(0);
$nl3 = $null.$null.$null; # 0 bytes for flags and encoding
$out = "";
foreach($frames as $ky=>$val) {
$n=strlen($val)+1;
$out.= $ky.mkFrmLen($n).$nl3.$val;
}
return $Hdr.str_pad($out,$tagLen,$null);
}
# Calculate Tag Length from bytes 6-10 of existing header
function calcDecTagLen($word) {
$m = 1;
$int = 0;
for ($i=strlen($word)-1;$i>-1;$i--) {
$int +=$m*ord($word[$i]);
$m=$m*128;
}
return $int;
}
# Make the 4 byte frame length value for the V2tag
function mkFrmLen($int) {
$hx = "";
while ($int>0) {
$n = $int % 256;
$hx = chr($n).$hx;
$int=floor($int/256);
}
return str_pad($hx,4,chr(0),STR_PAD_LEFT);
}
# Create the 128 byte V1 tag
function mkV1Tag() {
Global $frames;
$tagOut = "TAG".
adj($frames[_Title]).
adj($frames[_Artist]).
adj($frames[_Album]).
str_pad($frames[_Year],4).
str_pad(" ",29," ").
chr($frames[_TrackNo]).
chr($n);
return $tagOut;
}
# Pad the header to 30 characters
function adj($str) {
return substr(str_pad($str,30,chr(0)),0,30);
}
# This is a simple example for an mp3 in current folder
writeTags("01-Cognac Blues.mp3");
?>
The setHexTagLen can be figured out from the calcDecTagLen but here's some sample code.
<?php
function setHexTagLen($int) {
$n = pow(128,3);
$intVar = $int;
$m = "";
for ($i=0;$i<4;$i++) {
$m .= chr(floor($intVar/$n));
$intVar = $intVar % $n;
$n=$n/128;
}
return $m;
}
?>
11-Jul-2004 02:31
There are several highly developed id3 reader classes written in php that include id3v2 support, and support for other file formats (not just mpeg & id3). I recommend http://getid3.sourceforge.net/ as well as the id3 reader class integrated in the Zina is not Andromeda project (http://pancake.org/zina.html)
