META Data Binary Files? Need Help.

sbroad

Does anyone know of code or classes which will extract file META data from binary files?

Example, I would like to extract out the summary, title,copyright and stuff like that which is embedded in MP3 files.

Thanks
Scott

yelvington

google mp3 php

quickly turns up MP3 Archiver by Steve Oliver.

sbroad

Thank you very much,, this is what I have been looking for.

sbroad

Here is the code I used from MP3 archiver

I found the code at
http://www.pscode.com/vb/scripts/ShowCode.asp?txtCodeId=249&lngWId=8
for anyone else who needs it.

I pulled out the function getTag and added my own mp3 information for a test (first 2 lines) and it pulled the information out perfectly!

My question is, how did it work? Is the pointer just moved ahead in 30 spaces for each read and accomplished this way?

<?
$filetitle="1_1_ws.mp3";
$filename= "1_1_ws.mp3";
$fp=fopen($filename,"r");
fseek($fp,filesize($filename)-128);
$checktag=fread($fp,3);
echo "<table width='100%' border='1' bgcolor='#c0c0c0'><tr><td>";
echo "<a href=\"$url$filetitle\">$filetitle</a> </tr></td><tr><tr><tr bgcolor='#FFFFFF'><td>";
if ($checktag=="TAG") {
echo "\nSize: ".number_format(filesize($filename)/1000,2)." KBytes ";
echo "\nTitle: ".fread($fp,30)." ";
echo "\nAuthor: ".fread($fp,30)." ";
echo "\nAlbum: ".fread($fp,30)." ";
echo "\nCopyright: ".fread($fp,4)." ";
echo "\nComments: ".fread($fp,30)." ";
echo "</td></tr></table> ";
}else{
echo "Size: ".filesize($filename)." Bytes ";
echo "No Tag ";
echo "</td></tr></table> ";
fclose($filename);}
?>

keywords : mp3 meta information extract archiver file extractor binary audio

yelvington

Looks like an MP3 tag is a fixed-format record at the end of the file. Probably a C struct in its original incarnation. Reading it back into C would be much easier. This is because C is a typed language, where you can describe the sizes of components of a structure.

In PHP, you can fake a structure with an object definition, but you can't specify its dimensions, so you can't neatly import the data with a single fread() call.

Another way of importing the data in PHP would be to seek to the proper location (filesize - 128), then read the whole tag into a string in one fread() operation, then use substr() to extract the individual pieces.