iPod

Although Apple's iTunes program is very good at keeping a computer-based library synchronized to an iPod automatically, or for manually transferring tracks from your computer's iTunes library onto your iPod, it provides extremely limited functionality for transferring information in the opposite direction-from your iPod back to your computer.

One of the likely reasons for Apple to have taken such a restrictive approach to this is to combat piracy and thereby maintain good relations with the music labels that are currently selling their content via Apple's iTunes Store. In reality, however, there are any number of legitimate reasons why a user may want to copy music from their iPod back to their computer, such as recovering from a catastrophic system failure, or easily transferring a large iTunes library over to a new computer.

Unfortunately, with the exception of tracks purchased from the iTunes Store, which we'll discuss further later in this article, iTunes provides no method for transferring your music and other media content from your iPod back to your computer. It has therefore fallen to third-party developers to pick up where iTunes left off in this regard, and there are today a number of very robust and full-featured utilities that will do everything from basic copying of media content back to your hard drive all the way through to rebuilding your entire iTunes library using the information on your iPod, complete with playlists, ratings, and play count information.

In this tutorial, we will begin with a background on how music is stored on the iPod in the first place, and then look at the options available for copying music and other media files from the iPod back to your computer, both on an individual basis and en masse for a complete disaster-recovery scenario.

It should be noted that the information in this article applies to all past and current models of iPod, including the iPod nano, iPod mini, the iPod shuffle, and now even the iPod touch and iPhone. However, there is no guarantee that future generations of iPod will continue to support these methods. Further, this information does not apply to content stored on the Apple TV, since despite its integration with iTunes, a different synchronization technology is used for this device and there are presently no methods to recover content from the Apple TV without hacking into or physically disassembling the unit.

Under the Hood-How Content is stored on the iPod

Before we get into the details of how to copy media content from the iPod back to your computer, it's important to begin with a discussion of how that content is actually stored on the iPod. An understanding of how the iPod stores its content will make it more clear as to what the various recovery or copying options actually do, and help decide on what the best option is for a particular situation.

Unlike many other portable media players, the iPod stores its content using a database methodology. iTunes copies the content itself to a hidden directory structure on the iPod and then updates a database stored on the iPod. It is this database that is used both by iTunes and the iPod interface itself to index and catalog the content that is stored on the iPod.

For the most part, this database information is gleaned from the internal header tags within the media files themselves, in much the same way that iTunes indexes and catalogs your media library. Information such as the track name, artist, album, genre, and a myriad of other information that you can find for each track in iTunes is actually stored in each file, and the name of the file has no bearing on what iTunes or the iPod sees or how it catalogs any given media file. In fact, the only time the file name is ever used by iTunes is if the tags themselves are not present (or if the file format does not support tags, such as with WAV files).

The iPod database also contains additional information about your music that is not normally stored within the tracks themselves. This includes your playlists and the listing of their content, as well as track metadata such as rating, play count, last played time, skip count, last skipped time, and more.

This particular means of storing information on the iPod has both advantages and disadvantages. The major advantage to this approach is that music is catalogued in such a way that it is easily and rapidly accessible from the various menus on the iPod itself, without having to search through individual track information or build a separate cache. The disadvantage is that the music must be tagged properly in order for this to work, and of course this obscures the actual layout of the music files themselves, making it more difficult to find and copy specific tracks from the iPod back to the computer.

Fortunately, a number of third-party utilities have been developed that can read these iPod databases directly, and use them to not only locate specific tracks to recover, but in some cases even recover playlists and other additional metadata such as rating and play count.

On the iPod itself, all of the internal iPod information is located in a hidden folder called iPod_Control. Most of the information in this folder pertains to internal iPod operations, such as device configuration and settings and the library database described above. However, beneath this iPod_Control folder is a Music folder that contains all of the individual audio and video files that are stored on that particular iPod. The only information not stored here is photos, which we will discuss separately later in this article.

The files in the Music folder won't necessarily be organized in any meaningful way for a human, since they are expected to be accessed via the iPod's library database, which contains all of the information and other metadata for each track cross-referenced with the location of these individual files.

The times they are a-changin'-The 2007 iPod models, the iPhone and the iPod touch

Traditionally, as far as your operating system is concerned, the iPod has simply appeared to your computer as a removable storage device-basically an external hard drive. In fact, iTunes itself basically just accesses traditional iPod models in much the same way-media files are copied to the device as an external hard drive, and iTunes simply accesses the iPod's database directly and updates the information contained in it using normal file access methods.

Essentially, the traditional iPod models are "dumb" devices when it comes to synchronization with iTunes. The device itself doesn't "participate" in the synchronization process… iTunes itself does all the work, and the iPod just sits there connected as an external hard drive. When the sync is finished and the iPod is ejected, it returns to normal use, and since iTunes has updated the iPod's database, any new tracks that have been added will appear in the appropriate places.

This method allowed early iPods to work quite effectively without requiring complicated technology, but it had the obvious disadvantage that since the iPod wasn't involved in the synchronization process, any failure on the part of iTunes to properly update the iPod's database would lead to odd and inconsistent behaviour. This was most commonly observed when disconnecting the iPod prior to an iTunes sync being completed-iTunes wouldn't be able to update the database, and since the iPod itself didn't know what was going on, it would be left with an inconsistent or incomplete database of track information.

The iPod classic and iPod nano (video) released in September 2007 retained this same approach to synchronization with iTunes, but added an extra "checksum" in the iPod database to help ensure that it would be left in a more consistent state in the event of a problem occurring during synchronization with iTunes. Unfortunately, these changes broke compatibility with a number of third-party iPod management applications, since they needed to update the checksum when updating content on the iPod. There were some rumours at that time was that Apple had added "encryption" to the iPod database to deliberately break third-party applications. However, there is no truth to these rumours, and in fact applications that simply read the iPod database (such as many of those we will discuss further on in this tutorial) have been mostly unaffected by these changes. From an iPod recovery point of view, there are no significant differences between the 2007 traditional iPod models (iPod classic and iPod nano (video) ) and previous generations.

On the other hand, the iPod touch and iPhone introduced a completely new synchronization protocol for communicating with iTunes. Since these devices are running an OS X based operating system much like a computer, they no longer have to be passive targets for iTunes, but can participate in the synchronization process. With the iPod touch and iPhone, iTunes essentially hands the information off to the device for processing, and the device updates its own database. This ensures proper database integrity in the event that a problem occurs during synchronization, since the operating system on the iPod touch or iPhone can ensure that the database has been properly updated, even if the device is pulled from the cradle in the middle of a sync. This in fact was an important feature for the iPhone-the ability to pull the device to answer a call if it rings while syncing with iTunes.

The result of these changes on the iPod touch and the iPhone are that most of the traditional methods for recovering content will not work. Fortunately, many software developers have stepped in to fill this void as well, and in the past few months several existing applications have been updated and a few new ones released specifically to handle recovering content from iPod touch and iPhone.

Disaster Recovery

So you have a nice big 160GB iPod with your entire media library loaded onto it, synchronizing automatically with your iTunes library, when suddenly the unthinkable happens… Your computer's hard drive decides that it's been spinning for long enough, and gives up on you.

You now suddenly find yourself in the position where your only copy of your music library is on your iPod itself, and you need to get those tracks back off the iPod onto your computer, so you can rebuild your iTunes library.

In a situation where you've been using automatic synchronization with your iTunes library, and you suddenly find you no longer have an iTunes library to sync with, there are a couple of additional considerations that are important to keep in mind.

Automatic iPod synchronization from iTunes is, for the most part, a one-way experience. Some information does come back in the other direction, such as ratings and play counts, but the bottom line is that iTunes considers the library on your computer to be "authoritative"-meaning that the iPod mirrors the iTunes library, rather than the other way around.

The unfortunate downside to this is that if you have an empty iTunes library on your computer, an iPod that is automatically syncing to it will happily mirror the content of your empty library. In other words, everything on the iPod will be deleted and replaced with, well… nothing.

The good news, however, is that this is only really a problem if you're actually using the same library as you were syncing with before. iTunes is intelligent enough to notice when an iPod that you connect was previously associated to a different iTunes library database, and prompt you with a warning as to what you want to do next:

If you are trying to recover your music from your iPod, you obviously do not want to select Erase and Sync. Simply click Cancel instead, and your iPod will remain connected to your computer, but the auto-sync process will not run.

So what about those situations where you are connecting your iPod to your existing iTunes library? For example if you accidentally deleted a few tracks from your main iTunes library that you want to recover from your iPod. In this case, the iTunes automatic sync will run without notification since it's the same library database. Fortunately, iTunes offers a solution for this as well: Simply hold down the SHIFT+CTRL keys (on Windows) or CMD+OPT keys (on a Mac) while you are connecting your iPod to your computer.Keep holding these keys down until your actually see your iPod show up in the iTunes source list. This will prevent iTunes from running any kind of automatic sync when it detects the iPod, but the iPod will again remain connected and ready to work with.

Swinging Both Ways…

Keep in mind that if you're planning to use the features described in this article to use your iPod to transfer music between a Mac and a PC, your iPod itself needs to either be Windows-formatted so that both your Mac and PC can access it, or you will need to use a program like MediaFour's MacDrive to allow you to read your Mac-formatted iPod under Windows.

Note that this is not an issue with the iPod touch or the iPhone. These devices are not accessed as an external hard drive (see above), and the format therefore doesn't matter. Under the hood, they're always Mac formatted, since they're running OS X.