iTunes Store music - Is it censored? Does it have DRM?

[bollweevil]

Before I buy an album from the iTunes Store, I am wondering:

1) Will it be censored?

2) Will it have DRM on it?

Less importantly:

3) Is it true that the files will be 256 kbit/s AAC-encoded, with the filename suffix .m4a?

4) Can I move the location of the files on my hard disc after downloading? When I "rent" a movie from the iTunes store, I cannot move the file.

5) I hear that the iTunes Store puts a "watermark" on all downloaded files saying some of my personal information, to deter piracy. Can I read this "watermark" using a text editor like BBEdit, or is it encrypted?

 

[Makosuke]

1) If there is a censored and uncensored version available, the former will have a little grey "clean" badge beside its song title, while the latter will have a red "explicit" badge. If you see neither, I would assume it's an unedited version.

2) For songs, no. While (I think) the files are marked internally with the account used to purchase them, there is no protection whatsoever on audio files, and they can be copied, modified, whatevered, freely.

3) Yes; there were lo-fi versions in the past, but everything in the store is now supposed to be iTunes Plus quality, which is 256K.

4) Unlike video, which is DRM'd, you can do anything you want with the music files. If you go digging around in iTunes' folder and move them elsewhere without telling it iTunes will of course lose track of it, but it can be re-added to the library or played from a different app.

5) Not exactly sure in what form the watermark appears, but you can see the associated data by just doing a get info on the file in iTunes. I doubt it's encoded, so anything capable of reading metadata off the file will be able to see it.


If you want to test it for yourself, just grab the free Single of the Week and check it out. It should be the same as any other song you'd purchase.

 

[Nermal]

If you see neither, I would assume it's an unedited version.

That is not a safe assumption (I speak from experience). Listen to the previews to try to tell before purchase. In one case I couldn't tell from the previews, but Apple refunded the purchase price when I contacted support.

 

[bollweevil]

I took the plunge, I bought an album. Results:

Censorship: I cannot tell if it is censored, I have not yet heard a naughty word or a conspicuous gap in the lyrics. It might just be clean and wholesome music, in which case we have no data. Too bad.

DRM: There doesn't seem to be any.

Moved files: I moved the files and then double clicked them to open with iTunes. Surprisingly, iTunes realized that these were duplicates and it accommodated the move seamlessly. I had put the songs into two playlists, and then moved the files. After the move and double clicking the files, the iTunes playlists still worked. The library clearly knew to move the pointer to the data. I bet that metadata like playcount would have been kept too.

Watermark: The files do indeed say my:
Full name
Email address
Purchase date and time
These things are in cleartext, although I am afraid they may also be encoded in some less obvious way. This personal information is toward the beginning of the file, which is annoying. Metadata belongs at the end, so that it is easier to edit without rewriting the whole file to disc.

 

[Makosuke]

This personal information is toward the beginning of the file, which is annoying. Metadata belongs at the end, so that it is easier to edit without rewriting the whole file to disc.

I'm pretty sure that info is part of a more-or-less standard ID3 tag, which is by specification at the beginning of the file to aid in streaming applications--the player can identify the metadata without downloading the entire file. Makes perfect sense for anything large that you want to stream as serial data from a "dumb" server, and it's the same basic reason that HTML metadata is stored in the head of the file. The ability to trim something off the end of the file was not the primary concern when the format was developed, and I can see why--most video containers do the same thing for the same reason.

As for whether there's anything concealed in the audio stream itself, I'd actually wager not, but I'm sure if you ask Google you'll come up with an answer.

Either that, or set up two accounts, grab the free single of the week from each, strip off the ID3 tag, and see if the remaining audio data is identical.