Newbie - What is ID3 Tag?
Hi,
Okay... I'm new to MP3 ripping etc. and don't know what ID3 Tags are. I'm mostly interested in the iTunes "Convert ID3 Tags..." feature and what it's used for. Do I even need to use it? I've noticed that "convert ID3 tags" option is dimmed on songs I ripped to AAC using iTunes.
I've searched the forums but can't find info that explains this feature. I only find posts for Windows software.
Thanks in advance for helping a newbie.
pixelMAn
[515 byte] By [
pixelMan] at [2007-11-9 12:40:11]
# 1 Re: Newbie - What is ID3 Tag?
ID 3 tags are the text names used by iTunes and the iPod to identify songs.
The songs are sort of like a database and require some method of differentiating them from other songs, and that is how it is done.
I hope this helps.
# 2 Re: Newbie - What is ID3 Tag?
An ID3 tag is information appended to the end of an mp3 file. The various versions have added new info fields and allowed for more characters per field. The original ID3 tags were a fixed size (128 bits) and could not hold much information. With newer versions, more kinds of info have been added to the tags. If you select a track in iTunes and get info for it, the screen you'll see is all the v2.4 ID3 tag info.
"Convert ID3 tags" has two functions:
1. To make mp3 files backwards-compatible. Not all mp3 players read newer versions of ID3 tags, and in general, MP3CDs read version 1.1 only
2. To save the information in the file itself. iTunes stores metadata about files in its database (the file called "iTunes Music Library 4"). Were you to loose this database, any changes you'd made to tag info after ripping would be lost. This used to happed a lot with iTunes 2; the Library file would get corrupted and folks would have to trash it and start anew. One way of ensuring the data resided in the files instead of in the database was to select tracks and convert their ID3 tags to the latest version. With iTunes 3 and 4, losing the Library is less likely, since Apple implemented an xml backup.
The reason the option to convert for AAC files is greyed out is that AAC files do not have ID3 tags. This is where things get weird. AAC files (called "m4a" or "m4p" by your Mac) are pretty much just MPEG-4 files. From what I've heard and read, MPEG-4 files do have ID3 tags, but m4a and m4p files don't. I don't know why Aple did things this way, and I'm not sure how the information is being stored, but I know the info is stored in the file itself somehow because I've put songs on a CD-R and added the to iTunes on my work computer and iTunes displays all the metadata properly. My guess would be that the metadata is being stored the way that metadata for QuickTime files is stored, (QuickTime files have a "wrapper" around them that stores metadata) which makes sense, given that it is essentially QuickTime that's doing the encoding anyway.
# 3 Re: Newbie - What is ID3 Tag?
Thanks for the great information. And yes it totally helps. I figured it was the data being shown on the iPod and iTunes. I just didn't quite get all the discussions regarding it since some were having problems. Plus there wasn't a detailed explaination in iTunes help files defining the "convert id3 tags" function.
So, is it best then to convert the non-AAC file tags to version 1.1 if I ever intend to burn MP3 cds? But then I guess it doesn't matter much since the majority of my MP3s are in AAC format. And I'm also assuming that AAC don't currently play on MP3 cd players. It's good though that the tag information stays intact on data cds.
Thanks again.
