Monday, September 14, 2009

iTunesLP: The "first" (MPEG-21) Digital Item?

Apple recently released iTunesLP with which "the visual experience of the record album returns". Today, I've purchased the first iTunesLP (btw. 1st iTunes music thing ever!) to see what's behind this 'new format' and whether it can be considered as a digital item (as defined by MPEG-21). The album in question is "The Doors: 40th Anniversary Mixes" and comes with the regular media files which are placed in the regular iTunes directory structure. However, it also comes with a .itlp 'file' - at least this is what Mac OS X finder shows (cf. figure below).
However, what's behind is a simple directory structure comprising an index.html linking to a set of CSS files (css) and JavaScript files (controllers and src). Furthermore, the directory structure includes links to fonts, images, and videos required for the presentation of the LP and an Apple .plist file. The views directory provides something like the sub-pages from an album's booklet.
That is, the iTunesLP is basically a Web site (i.e., HTML+CSS+JavaScript) and iTunes becomes a ordinary Web browser? Hmm, finally I tried to transfer the iTunesLP to the iPhone but it seems that the iPhone cannot play the album in the same way iTunes does.

On the other hand, is it possible to realize the functionality provided by iTunesLP with MPEG-21 tools? I would say "Yes, it can"! In particular, the relationship between the various assets (text, images, videos, etc.) can be described using Digital Item Declaration and Digital Item Identification is used to identify the whole album and individual tracks. The interaction can be achieved by Digital Item Processing which enables the inclusion of ECMAScript (JavaScript) within a Digital Item. Finally, the File Format provides means to package the digital item into a single file - based on the ISO base media file format and compatible to .mp4 - enabling easy transaction among users within the whole value network.

So, is the iTunesLP a digital item? - Yes! Is the iTunesLP compatible with an MPEG-21 Digital Item - No (it is not compliant to MPEG-21) / Yes (it can be realized using MPEG-21). Additionally, MPEG-21 provides means to package a Digital Item into a single file and it is interoperable.

1 comment:

Unknown said...

Out of the 520 MB of the .itlp "file", more than 90% are used for the interview videos.
While Mac OS X shows this .itlp "file" as a file, Windows and Linux reveal that it is a folder.

Let's have a look inside the .itlp folder (or whatever you may call it):
It contains several sub folders, e.g., "audio" (a small audio loop for the "home page"), "images" (mostly JPEG files, even the lyrics are JPEG files), and some folders for HTML and JavaScript files.

But the actual content (i.e., the songs and the music video) are actuallly outside the .itlp folder in separate files, with a total size of approximately 150 MB. So, the .itlp folder contains everything that was built around the songs to give the experience of an album.

It also contains an "index.html" file, exactly like web sites. However, only Safari seams to be capable of showing this home page pretty much like what you see in iTunes. Firefox 3.5.3 and IE 8.0 only show a black screen. The HTML source code reveals that the "index.html" file only loads some Stylesheets and JavaScript. The only thing inside the "body" is a single "div" tag. I guess that everything else is loaded dynamically into this page. (Not exactly the state of the art of creating web site, but it's only intended for iTunes anyway.)

All in all, itunesLP behaves like a web site, but a web site that you need a certain browser for, which is iTunes.

Concerning the conversion into an MPEG-21 file, the biggest problem appears to be the extraction of useful metadata from iTunesLP. This might resemble to information retrieval from web sites that were built in the 1990s.
Of course, the files from the .itlp folder could all blindly be packed into an MPEG-21 file, but (IMHO) that's not really the goal of the MPEG-21 file format.