Reading format of MP3 files

[Kiana]

So basically, you know how on iTunes and most music players, you can edit 'properties' of files such as artist, title, album, etc., right?

Does anyone know where that's stored? Is that part of the MP3 standard format? How could I extract/modify this information?

[hanst99]

Those aren't part of the MP3 standard. They are tags that are positioned either at the beginning or at the end of the MP3, see ID3 or APE.

[Kiana]

Thanks, helped lots!

For anyone else who wants it:
http://www.id3.org/id3v2.4.0-structure

[george135]

Just use COM

[hanst99]

Huh? What does COM have to do with MP3?

[modoran]

Windows Explorer and Windows Media Player uses COM to read ID3 tags from mp3 files and any application can do the same.
You need to #include <wmsdk.h>, link against wmvcore.lib and read MSDN docs. Windows Media SDK comes with a working sample to read/set id3 tags.

The bad thing is that windows COM interface does NOT read/write ID3v2.4 tags even today (tested in windows 7).

[hanst99]

Wikipedia wrote:

Component Object Model (COM) is a binary-interface standard for software componentry introduced by Microsoft in 1993. It is used to enable interprocess communication and dynamic object creation in a large range of programming languages.

You aren't talking about that COM, are you?

[modoran]

Yes, that is COM.

[hanst99]

You were talking about COM as if it was some sort of library. It's just a windows standard for object data. I don't know if you can imagine this, but this had me confused.

[modoran]

COM it is just an interface, that's right. Almost all Microsoft products uses it.
Anyway, to access wmvcore.dll (this is the real library for decoding mp3/wma and other files) you need to use COM.
Even new formats can be decoded using the same interface ( "multimedia codecs" are nothing more than COM servers).