Featured Content Page about: itunes

iTunes is a proprietary digital media player application, used for playing and organizing digital music and video files. The program is also an interface to manage the contents on Apple's popular iPod digital media players as well as the iPhone. Additionally, iTunes can connect to the iTunes Store via the Internet to purchase and download music, music videos, television shows, applications, iPod games, audiobooks, various podcasts, feature length films and movie rentals (not available in all countries), and ringtones (available only in the USA). It is also used to download applications for the iPhone and iPod touch as long as they are running iPhone OS 2.X.iTunes was introduced by Apple Inc. on January 9, 2001, at the Macworld Expo in San Francisco. The latest version, iTunes 8, was announced at Apple's September 2008 keynote Let's Rock.

iTunes is available as a free download for Mac OS X, Windows Vista, and Windows XP from Apple's website. It is also bundled with all Macs, and some HP and Dell computers. Older versions are available for Mac OS 9, OS X 10.0-10.3, and Windows 2000.

History

SoundJam MP, developed by Jeff Robbin and Bill Kincaid and released by Casady & Greene in 1999, became the basis for iTunes when Apple purchased it in 2000. Apple added a new user interface and the ability to burn CDs, and removed its recording feature and skin support, and released it as iTunes in January 2001. Originally a Mac OS 9-only application, iTunes began to support Mac OS X when version 2.0 was released nine months later, which also added support for the original iPod. Version 3 dropped Mac OS 9 support but added smart playlists and a ratings system. In April 2003, version 4.0 introduced the iTunes Store; in October, version 4.1 added support for Microsoft Windows 2000 and XP. Version 7.0 introduced gapless playback and Cover Flow in September 2006. In March 2007, iTunes 7.1 added support for Windows Vista, and 7.4 marked the end of Windows 2000 support. iTunes lacked support for 64-bit versions of Windows until the 7.6 update on January 16, 2008. iTunes is currently supported under any 64-bit version of Windows Vista, although the iTunes executable is still 32-bit. The 64-bit versions of Windows XP and Windows Server 2003 are not supported by Apple, but a workaround has been discovered for both operating systems. The last major update, version 8.0, added Genius playlists, grid view, and a new default visualizer.

A version of iTunes was shipped with cell phones from Motorola, which included the ability to sync music from an iTunes library to the cellphone, as well as a similar interface between both platforms. Since the release of the iPhone, Apple has stopped distributing iTunes with other manufacturers' phones in order to concentrate sales to Apple's device.

Features

iTunes is an application that allows the user to manage audio and video on a personal computer, acting as a front end for Apple's QuickTime media player. Officially, using iTunes is required in order to manage the audio of an Apple iPod portable audio player, although alternative software does exist. Users can organize their music into playlists within one or more libraries, edit file information, record Compact Discs, copy files to a digital audio player, purchase music and videos through its built-in music store, download free podcasts, back up songs onto a CD or DVD, run a visualizer to display graphical effects in time to the music, and encode music into a number of different audio formats. There is also a large selection of free internet radio stations to listen to.

Additionally, users can add PDF files to their library (to add digital liner notes to their albums, for example), but the PDFs cannot be transferred to or read on an iPhone or iPod. However, iPhone/iPod Touch apps exist to sync any type of file to and from the device to an ''iDisk'' using Apple's MobileMe service.

In the most recent version, iTunes 8.0, the preferences menu was given a complete makeover. The result added very few new options, but instead removed several options. For example, iTunes once gave users the option to display arrows beside the selected song's title, artist, album, and genre that link directly to the iTunes Music Store. Now these arrows are not removable, except through the direct editing of a preferences file.

Media management

iTunes keeps track of songs by creating a virtual library, allowing users to access and edit a song's attributes. These attributes, known as metadata, are stored in two separate library files.

The first is a binary file called ''iTunes Library'' and it uses a proprietary file format (''ITL''). It caches information like artist and genre from the audio format's tag capabilities (the ID3 tag, for example) and stores iTunes-specific information like play count and rating. iTunes typically reads library data only from this file.

The second file, ''iTunes Music Library.xml'', is refreshed whenever information in iTunes is changed. It uses an XML format, allowing developers to easily write applications that can access the library information (including play count, last played date, and rating, which are not standard fields in the ID3v2.3 format). Apple's own iDVD, iMovie, and iPhoto applications all access the library.

If the first file is corrupted, iTunes will attempt to reconstruct it from the XML file. Detailed third-party instructions regarding this are documented elsewhere. There have been some concerns, voiced by Mark Pilgrim, that this feature will create an ''undocumented binary blackhole'' because the recovery from the XML file may not work.

It has also been noted that iTunes does not automatically track changes to actual files in the library. If a file is moved or deleted, iTunes will display an exclamation mark beside the library entry and the user will need to manually amend the library record. There have been a number of third party tools created to address this problem.

iTunes supports ripping from CDs, but not from DVDs. However, in 2008, Apple and select movie studios introduced ''iTunes Digital Copy,'' a bonus feature on some DVDs that provides a copy-protected, iTunes-compatible file for select films. As with any digital music management, users must use an analog-to-digital converter to import analog recordings (such as audio cassettes or vinyl records) to their iTunes libraries.

Library views

iTunes users may choose to view their music and video libraries in one of four ways: as a list, as a list with accompanying album artwork, in Cover Flow (a side-scrolling catalog of album artwork), or in Grid View.

The standard list view displays library files with many optional detail fields, including name, artist, album, genre, user rating, play count, and so forth. Item backgrounds alternate between white and a light blue-gray for readability.

The list with accompanying album artwork is much the same, only the list is broken up by albums, with the artwork as a header to the list. Although this allows users to browse content more visually, sorting the list view by name will accordingly break up the library into redundant instances of each album. Accordingly, as with Cover Flow view, the second view mode is most appropriate for users who sort their libraries by album.

Cover Flow displays all of the user's album art as CD covers in a slideshow format. It sorts the albums into artist, genre, etc. Compilation albums are only shown as a single album cover if the compilation tag for each of the album's tracks is turned on. If the song(s) from the album were imported from a 'mix' CD, the album artwork will be displayed as a default music note pictures.

Grid View is similar to Cover Flow, displaying the user's cover art in a grid rather than a side-scrolling format. Albums can also be sorted into groups by artist, genre, or composer.

iTunes also sorts with secondary parameters, album by artist and album by year, to make its artwork-centered interfaces more intuitive.

Library sharing

A user's iTunes Library can be shared over a local network using the closed, proprietary Digital Audio Access Protocol (DAAP), created by Apple for this purpose. DAAP relies on the Bonjour network service discovery framework, Apple's implementation of the Zeroconf open network standard. Apple has not made the DAAP specification available to the general public, only to third-party licensees such as Roku. However, the protocol has been reverse-engineered and is now used to stream playlists from non-Apple software (mainly on the Linux platform).

DAAP allows shared lists of songs within the same subnet to be automatically detected. When a song is shared, iTunes can stream the song but won't save it on the local hard drive, in order to prevent unauthorized copying. Songs in Protected AAC format can also be accessed, but authentication is required. A maximum of five users may connect to a single user every 24 hours. The multiple, alternate ''View'' options normally available to iTunes users including ''Cover Flow'' are disabled when viewing a shared library over a network.

Library sharing was first introduced with iTunes 4.0, where users could freely access shared music anywhere over the Internet, in addition to one's own subnet, by specifying IP addresses of remote shared song libraries. Apple quickly removed this feature with version 4.0.1, claiming that users were violating the End User License Agreement.

With the release of iTunes 7.0, Apple changed their implementation of DAAP. This change prevents any third-party client, such as a computer running Linux, a modified Xbox, or any computer without iTunes installed, from connecting to a remote iTunes repository. iTunes will still connect as a client to other iTunes servers and to third-party servers.

File format support

iTunes 8 can currently read, write and convert between MP3, AIFF, WAV, MPEG-4, AAC and Apple Lossless.

iTunes can also play any audio files that QuickTime can play (as well as some video formats), including Protected AAC files from the iTunes Store and Audible.com audio books. There is limited support for Vorbis and FLAC enclosed in an Ogg container (files using the FLAC container format are not naturally supported) or Speex codecs with the Xiph QuickTime Components. Because tag editing and album art is done within iTunes and not Quicktime, these features will not work with these QuickTime components. iTunes currently will not play back HE-AAC/aacPlus audio streams correctly. HE-AAC/aacPlus format files will play back as 22 kHz AAC files (effectively having no high end over 11 kHz), and HE-AAC streaming audio (which a number of Internet radio stations use) will not play back at all. The latest version of iTunes (Win/Mac) supports importing audio CDs with the default iTunes standard file format of AAC at 256 kbit/s, but users can choose from 16 kbit/s to 320 kbit/s constant bit rates (CBR) in either AAC or MP3.

Importing of audio CDs into MP3 or AAC formats can also be accomplished using variable bitrate (VBR) encoding. However, a double-blind experiment conducted in January 2004 of six MP3 encoders noted that the iTunes encoder came last, in that the quality of the files produced by iTunes was below par. It was stated in the final results that these tests only covered VBR encodings, thus iTunes may have performed better with a Constant bitrate (CBR).

The Windows version of iTunes can automatically transcode DRM-free WMA (including version 9) files to other audio formats, but does not support playback of WMA files and will not transcode DRM protected WMA files. Telestream, Inc. provides free codecs for Mac users of QuickTime to enable playback of unprotected Windows Media files. These codecs are recommended by Microsoft.

File metadata

For MP3 files, iTunes writes tags in ID3v2.2 using UCS-2 encoding by default, but converting them to ID3v2.3 (UCS-2 encoding) and ID3v2.4 (which uses UTF-8 encoding) is possible via its ''Advanced'' > ''Convert ID3 Tags'' toolbar menu. If both ID3v2.x and ID3v1.x tags are in a file, iTunes ignores the ID3v1.x tags.

AAC and Apple Lossless files support Unicode metadata, stored in the MP4 container as so-called ''Atoms''. The QuickTime plugin that supports the OGG container format has no support for tag editing or album art. However, a worldwide crash of iTunes' authentication servers on July 11, 2008, the day that the iPhone 3G was released, caused major issues. In some cases, AT&T and Apple Store employees told iPhone buyers to attempt to activate it at home. Also affected were original iPhone users attempting to upgrade to the 2.0 firmware. UK Apple, O2 and Carphone Warehouse stores were further impacted, as carrier O2's contract processing servers (known as Gateway) could not handle the amount of new contracts and upgrades happening on launch day. Some stores reverted to hand written contracts, while others held stock.

Printing

To compensate for the lack of a physical CD, iTunes can print custom-made jewel case inserts as well as song lists and album lists.

After burning a CD from a playlist, one can select that playlist and bring up a dialog box with several print options. The user can choose to print either a single album cover (for purchased iTunes albums) or a compilation cover (for user-created playlists). iTunes then automatically sets up a template with art on one side and track titles on the other.

iMix

An iMix is a user-created playlist published in the iTunes Store. iMixes were first introduced in iTunes version 4.5. Anyone can create an iMix free of charge. iMixes are limited to 100 songs and must feature content available on the iTunes Store. iMixes are public and searchable by any iTunes user. Users may also rate any iMix using a five-star system. iMixes are active for one year from their original published date. Users can publish their iTunes iMix to their blog, profile page or website such as Yahoo! 360°, Facebook, or MySpace.

Internet radio

iTunes 1.0 came with support for the Kerbango Internet radio tuner service, giving iTunes users a selection of some of the more popular online radio streams available. When Kerbango went out of business in 2001, Apple created its own Web radio service for use with iTunes 2.0 and later. As of February 2008, the iTunes radio service features 1795 ''radio stations,'' mostly in MP3 streaming format. Programming covers many genres of music and talk, including streams from both internet-only sources as well as streamed traditional stations. iTunes also supports the .pls and .m3u stream file formats used by Winamp, enabling iTunes to access almost any stream using that format.

Since the release of iTunes 7, Apple no longer promotes the Internet radio feature. However, it remains in the QuickTime 7.0.4, and iTunes EULA used by iTunes 6.0.5.20. With iTunes 7, the ''Radio'' item has reappeared as an optional source in the preferences, along with its stations. However, as of iTunes 8, radio is checked by default and the stations can be accessed by selecting ''Radio'' under ''Library.'' Some third-parties offer iTunes plugins that add additional radio stations.

In addition, a user is able to enter their own stream feeds to listen to in their own music library. This is done by ''Advanced'' > ''Open Audio Stream...'' or by the hotkey Ctrl-U (PC) or Command-U (Mac).

Plugins

iTunes supports visualizer plugins and device plugins. Visualizer plugins allow developers to create music-driven visual displays. The visualizer plug-in software development kits for Mac and Windows can be downloaded for free from Apple. Device plugins allow support for additional music player devices, but Apple will only license the APIs to authentic OEMs who sign a non-disclosure agreement.

The Big Top 40

iTunes are joined with the UK chart show The Big Top 40. The top 10 is produced by listeners interacting with the iTunes music downloads.