Digital audio player

Apple iPod nano (third-generation)

A digital audio player, more commonly referred to as an MP3 player, is a consumer electronics device that stores, organizes and plays audio files. Some DAPs are also referred to as portable media players as they have image-viewing and/or video-playing support.

History

Grundig MPAXX MP-100 player with a 32 MB MMC card

The most popular predecessor to digital audio player is the portable CD, which was commonly known as a"Portable Audio Devices".

Briton Kane Kramer designed one of the earliest digital audio players, which he called the IXI. His 1979 prototype was capable of approximately 3.5 minutes of audio playback but it did not enter commercial production. The related patents expired in 1988. Apple Inc. hired Kramer as a consultant and presented his work as an example of prior art in the field of digital audio players during their litigation with Burst.com almost two decades later.

The first mass-produced DAP was created in 1997 by SaeHan Information Systems, which domestically sold its “MPMan” player in the middle of 1998. The South Korean company then licensed the players to Eiger Labs which distributed them—now branded as Eiger Labs MPMan F10—to the North American market during the summer of 1998. The flash-based players were available in 16 MB storage capacity.

The Rio PMP300 from Diamond Multimedia was introduced in September 1998, a few months after the MPMan. It was a success during the holiday season, with sales exceeding expectations. Interest and investment in digital music were subsequently spurred from it. Because of the player's notoriety as the target of a major lawsuit, the Rio is erroneously assumed to be the first DAP.

In 1998, Compaq developed the first hard drive based DAP using a 2.5" laptop drive. It was licensed to HanGo Electronics (now known as Remote Solution), which first sold the PJB-100 (Personal Jukebox) in 1999. The player had an initial capacity of 4.8 GB, which was advertised to be able to hold 1200 songs.

In October 2001, Apple Computer (now known as Apple Inc.) unveiled the first generation iPod, the 5 GB hard drive based DAP with a 1.8" Toshiba drive. With the development of a minimalistic user interface and a smaller form factor, the iPod was initially notable within users of the Macintosh community. In July 2002, Apple introduced the second generation update to the iPod. It was compatible with Windows computers through Musicmatch Jukebox (now known as Y!Music Musicmatch Jukebox). The iPod series, which grew to include microdrive and flash-based players, has become the market leader in DAPs.

In 2002, Archos released the first official PMP, the Archos Jukebox Multimedia. Manufacturers have since implemented abilities to view images and play videos into their devices.

Although online music services such as RealNetworks’ Rhapsody also offer legal downloads through a subscription plan, the launch of the iTunes Store in 2003 established the model of selling individual songs and albums for purchase.

Operation

Connecting a SanDisk Sansa Clip to a computer.

Digital sampling is used to convert an audio wave to a sequence of binary numbers that can be stored in a digital format, such as MP3. Common features of all MP3 players are a memory storage device, such as flash memory or a miniature hard disk drive, an Embedded processor, and an audio Codec microchip to convert compressed sound into analog form that is then played through the speaker jack.

Most DAPs are powered by rechargeable batteries, some of which are not user replaceable. Listening to music stored on DAPs is typically through earphones and stereo systems connected with a 3.5 mm jack.

Types

Close-up view of the Philips GoGear SA1110 flash-based player

An embedded hard drive-based player (Creative ZEN Vision:M)

An MP3 CD player (Philips Expanium)

Digital audio players are generally categorized by storage media:

• Flash-based Players: These are non-mechanical solid state devices that hold digital audio files on internal flash memory or removable flash media called memory cards. Due to technological advancements in flash memory, these originally low-storage devices are now available commercially ranging up to 32 GB. Because they are solid state and do not have moving parts they require less battery power and may be more resilient to hazards such as dropping or fragmentation than hard disk-based players. Basic MP3 player functions are commonly integrated into USB flash drives.
• Hard drive-based Players or Digital Jukeboxes: Devices that read digital audio files from a hard disk drive (HDD). These players have higher capacities currently ranging up to 250 GB. At typical encoding rates, this means that thousands of songs can be stored on one player.
• MP3 CD Players: Portable CD players that can decode and play MP3 audio files stored on CDs.
• Networked audio players: Players that connect via (WiFi) network to receive and play audio.

Common audio formats

MP3 is the dominant format, and is nearly universally supported. The main alternative formats are AAC and WMA. Unlike MP3, these formats support DRM restrictions that are often implemented into files from paid download services. Open source formats, which are completely patent-free, are available - though less widely supported. Examples include Ogg Vorbis, FLAC, and Speex. Finally, a recent newcomer is MPEG 4, which is quickly starting to receive adoption by several digital audio players.

Controversy

Further information: [[:iTunes Store, and Digital Rights Management]]

Although these issues aren't usually controversial within digital audio players, they are matters of continuing controversy and litigation, including but not limited to content distribution and protection, and digital rights management (DRM).

Lawsuit with RIAA

The Recording Industry Association of America (RIAA) filed a lawsuit with Diamond Multimedia for its Rio players, alleging that the device encouraged copying music illegally. But Diamond won a legal victory on the shoulders of the Sony Corp. v. Universal City Studios case and DAPs were legally ruled as electronic devices.

See also

• Comparison of portable media players
• USB mass storage device class
• Internet radio device
• Media Transfer Protocol

External links

• Collecting MP3 Portables – Part I, Part II and Part III - Richard Menta's three-part article covers the first digital audio players on the market with pictures of each player.
• How Your Electronics Work: MP3 Players - Detailed explanation of engineering concepts and architecture used to build DAPs.