Digital audio player

Digital audio player

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

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. [ [http://www.foxnews.com/story/0,2933,419522,00.html British Man Says He Invented iPod in 1979] , Foxnews.com, 9/09/2008]

The first mass-produced DAP was created in 1997 by SaeHan Information Systems, which domestically sold its “MPMan” player in the middle of 1998. [cite web|url=http://reviews.cnet.com/4520-6450_7-5622055-1.html|title=Introducing the world's first MP3 player|last=Van Buskirk|first=Eliot|publisher=CNET] 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. [cite web|url=http://www.mp3playerlimelight.com|title=MP3 Players - The Basics and History] 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. [cite web|url=http://www.antiqueradio.com/Dec04_Menta_mp3pt1.html|title=Collecting MP3 Portables -- Part 1|last=Menta|first=Richard|publisher=Antique Radio Classified] Interest and investment in digital music were subsequently spurred from it. [cite press release|url=http://news.harmony-central.com/Newp/1998/Rio-PMP300.html|date=1998-09-14|title=Diamond Multimedia Announces Rio PMP300 Portable MP3 Music Player|accessdate=2007-12-05|publisher=Harmony Central] Because of the player's notoriety as the target of a major lawsuit, the Rio is erroneously assumed to be the first DAP. [cite news|url=http://www.news.com/Bragging+rights+to+the+worlds+first+MP3+player/2010-1041_3-5548180.html|title=Bragging rights to the world's first MP3 player CNet.com article on the first manufactured DAPs.]

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. [cite news|url=http://www.eetimes.com/story/OEG20000818S0035|last=Yoshida|first=Junko|coauthors=Margaret Quan|title=OEMs ready to roll on jukeboxes for Net audio|pages=1|publisher=EE Times|date=2000-08-18|accessdate=2007-12-05]

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. [cite press release|url=http://www.archos.com/corporate/press/press_releases/PR_ARCHOS_Gen_5_Availability.pdf|title=ARCHOS Generation 5 Available Worldwide|publisher=Archos|date=2007-09-12|accessdate=2007-12-05] Manufacturers have since implemented abilities to view images and play videos into their devices.

Although online music services such as RealNetworksRhapsody 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

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

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. [cite press release|url=http://asia.creative.com/corporate/pressroom/releases/welcome.asp?pid=12867|title=Creative Introduces the World's First 32GB Flash Memory-based Portable Media Player with the Latest Credit-Card sized ZEN|date=2007-12-03|accessdate=2007-12-04|publisher=Creative] 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. [cite web|url=http://secure.serverlab.net/shop/merchant.mvc?Screen=PROD&Product_Code=5250&Category_Code=ESP&Store_Code=T00107|title=Wolverine ESP 250 GB|publisher=Wolverine Data|accessdate=2008-01-02] 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. [ [http://devices.natetrue.com/musicap/ DIY Networked Audio Player] ]

Common audio formats

MP3 is the dominant format, and is nearly universally supported. [cite web|url=http://gale.cengage.com/reference/peter/200712/amazon.htm|title=Péter's Digital Reference Shelf - Amazon MP3|accessdate=2008-04-17] 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

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, [cite court|litigants=RIAA v. Diamond|court=9h Cir.|date=1999-06-15|url=http://www.ca9.uscourts.gov/ca9/newopinions.nsf/04485f8dcbd4e1ea882569520074e698/ddc79aee7dcda44288256e5a007184a3?OpenDocument official documentation.] 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. [cite web|url=http://www.virtualrecordings.com/rio.htm|title=Court Gives "Go-Ahead" to Digital Music Revolution|publisher=Virtual Recordings|last=Gross|first=Robin D|accessdate=2007-12-05]

ee also

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

References

External links

* [http://www.antiqueradio.com/Dec04_Menta_mp3pt1.html Collecting MP3 Portables – Part I] , [http://www.antiqueradio.com/Apr05_Menta_mp3.html Part II] and [http://www.antiqueradio.com/Jul05_Menta_MP3s.html Part III] - Richard Menta's three-part article covers the first digital audio players on the market with pictures of each player.
* [http://www.howyourelectronicswork.com/2008/07/ipods-other-mp3-players.html How Your Electronics Work: MP3 Players] - Detailed explanation of engineering concepts and architecture used to build DAPs.


Wikimedia Foundation. 2010.

Игры ⚽ Нужна курсовая?

Look at other dictionaries:

  • digital audio player — noun A device for storing and playing audio data that has been recorded in a digital file format (abbrev DAP) • • • Main Entry: ↑digit …   Useful english dictionary

  • Digital audio — Digital music redirects here. For a kind of modern music composed by digital means, see electronic music. A sound wave, in gray, represented digitally, in red (after quantization and zero order hold). Digital audio is sound reproduction using… …   Wikipedia

  • Audio player — refers to a device or application that is capable of playback of audio data. In the strict sense of the term any device capable of audio playback falls under this category, although usually only digital equipment or software is meant.*Digital… …   Wikipedia

  • Audio player (software) — An audio player is a kind of media player for playing back digital audio, including optical discs such as CDs, SACDs, DVD Audio, HDCD, and audio files.In addition to VCR like functions like playing, pausing, stopping, rewinding, and forwarding,… …   Wikipedia

  • Digital Audio Tape — can also refer to a compact cassette with digital storage: DCC or one of several digital reel to reel formats Digital Audio Tape A 90 minute DAT cart …   Wikipedia

  • Digital Audio Control Protocol — (DACP) is a protocol used by the Apple Remote application (app) on iOS mobile devices (iPad, iPhone and iPod Touch) to control iTunes running on a remote computer. By connecting the remote computer to loudspeakers, directly or indirectly, for… …   Wikipedia

  • Digital audio workstation — A digital audio workstation (DAW) is an electronic system designed solely or primarily for recording, editing and playing back digital audio. DAWs were originally tape less, microprocessor based systems such as the Synclavier and Fairlight CMI.… …   Wikipedia

  • Rio (digital audio players) — Rio was the brand name of a line of digital audio players, best known for producing the Diamond Rio model that was the impetus for a lawsuit in 1998 by the Recording Industry Association of America. That lawsuit eventually failed, leading the way …   Wikipedia

  • Portable audio player — A portable audio player is a personal mobile device that allows the user to listen to recorded audio while mobile. Portable audio players became possible in the 1970s and continue to be developed today. The technology used in such players… …   Wikipedia

  • Decibel Audio Player — Saltar a navegación, búsqueda Decibel Audio Player …   Wikipedia Español

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”