1. History

1.1. Digital Audio Player

In 1981, Kane Kramer filed for a UK patent for the IXI, the first Digital Audio Player.^[1] UK patent 2115996 was issued in 1985, and U.S. Patent 4,667,088 was issued in 1987.^[2] The player was as big as a credit card and had a small LCD screen, navigation and volume buttons and would have held at least 8MB of data in a solid-state bubble memory chip with a capacity of 3½ minutes' worth of audio. Plans were made for a 10-minute stereo memory card and the system was at one time fitted with a hard drive which would have enabled over an hour of recorded digital music. Later Kramer set up a company to promote the IXI and five working prototypes were produced with 16-bit sampling at 44.1 kilohertz with the pre-production prototype being unveiled at the APRS Audio/Visual trade exhibition in October 1986. However, in 1988 Kramer's failure to raise the £60,000 required to renew the patent meant it entering the public domain, but he still owns the designs.

In 1987 a German research institute, part of the Fraunhofer-Gesellschaft, started the research program for coding music with the high quality and low bit-rate sampling at its institute. The project was controlled by an expert in mathematics and electronics, Karlheinz Brandenburg.

The Listen Up Player was released in 1996 by Audio Highway. It could store up to an hour of music, but despite getting an award at CES only 25 copies were made.^[3][4]

1.2. MP3 Player

MP3 was introduced as an audio coding standard in 1994. It was based on several audio data compression techniques, including the modified discrete cosine transform (MDCT), FFT and psychoacoustic methods.^[5]

In 1997, the world's first MP3 player, the MPMan F10, was developed by a South Korean company SaeHan Information Systems.^[6] The world's first car audio hard drive-based MP3 player was also released in 1997 by MP32Go and was called the MP32Go Player. It consisted of a 3GB IBM 2.5" hard drive that was housed in a trunk-mounted enclosure connected to the car's radio system. It retailed for $599 and was a commercial failure.^[7] The first handheld portable MP3 player released on the American market was the Eiger Labs F10, a 32MB imported version of the MPMan F10 that appeared in the summer of 1998. It was a very basic unit and wasn't user-expandable, though owners could upgrade the memory to 64MB by sending the player back to Eiger Labs with a check for $69.00 plus $7.95 shipping.

Another early MP3 player was the Rio PMP300 from Diamond Multimedia, introduced in September 1998. The Rio was a big success during the Christmas 1998 season as sales significantly exceeded expectations, spurring interest and investment in digital music. The RIAA soon filed a lawsuit alleging that the device abetted illegal copying of music, but Diamond won a legal victory on the shoulders of Sony Corp. v. Universal City Studios and MP3 players were ruled legal devices. Eiger Labs and Diamond went on to establish a new segment in the portable audio player market and the following year saw several new manufacturers enter this market.

Other early MP3 portables include Sensory Science's Rave MP2100, the I-Jam IJ-100 and the Creative Labs Nomad. These portables were small and light, but only held enough memory to hold around 7 to 20 songs at normal 128kbit/s compression rates. They also used slower parallel port connections to transfer files from PC to player, necessary as most PCs then used the Windows 95 and NT operating systems, which did not have native support for USB connections. As more users migrated to Windows 98 by 2000, all players went USB.

In 1999 the Personal Jukebox (PJB-100) designed by Compaq and released by Hango Electronics Co had 4.8GB, which held about 1,200 songs, and invented what would be called the jukebox segment of digital music portables. This segment eventually became the dominant type of digital music player.

Also at the end of 1999 the first in-dash MP3 player appeared. The Empeg Car and Rio Car (renamed after it was acquired by SONICblue and added to its Rio line of MP3 products) offered players in several capacities ranging from 5GB to 28GB. The unit didn't catch on as SONICblue had hoped, though, and was discontinued in the fall of 2001.

Sony entered the digital audio player market in 1999 with the Vaio Music Clip and Memory Stick Walkman, however they were technically not MP3 players as it did not support the MP3 format but instead Sony's own ATRAC format and WMA. The company's first MP3-supporting Walkman player did not come until 2004.^[8]

There are several types of MP3 players:

• Devices that play CDs. Often, they can be used to play both audio CDs and homemade data CDs containing MP3 or other digital audio files.
• Pocket devices. These are solid-state devices that hold digital audio files on internal or external media, such as memory cards. These are generally low-storage devices, typically ranging from 128MB to 1GB, which can often be extended with additional memory. As they are solid state and do not have moving parts, they can be very resilient. Such players are generally integrated into USB keydrives.
• Devices that read digital audio files from a hard drive. These players have higher capacities, ranging from 1.5GB to 100GB, depending on the hard drive technology. At typical encoding rates, this means that thousands of songs—perhaps an entire music collection—can be stored in one MP3 player. Apple's popular iPod player is the best-known example.

2. Equipment

Generally speaking, MP3 players are portable, employing internal or replaceable batteries and headphones, and may be connected to car and home stereos via a wireless connection such as bluetooth. Some MP3 players also include FM radio tuners.

Many MP3 players can encode directly to MP3 or other digital audio format directly from a line in audio signal (radio, voice, etc.).

Devices such as CD players can be connected to the MP3 player (using the USB port) in order to directly play music from the memory of the player without the use of a computer.

Modular MP3 keydrive players are composed of two detachable parts: the head (or reader/writer) and the body (the memory). They can be independently obtained and upgradable (one can change the head or the body; i.e. to add more memory).