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* ATRAC on MiniDisc is gapless through the use of TOC ( Table of Contents ).
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ATRAC and on
In late August 2007, Sony released an email to customers of its Online Music Store ( Connect ) stating that Sony would shut down the service and begin to phase out the ATRAC codec on any future version of the Walkman portable device.
This transition away from the ATRAC codec was to allow the Walkman line to be adopted by more potential customers and their specific and unique preferences on online music services.
According to ATRAC engineers, ATRAC algorithms were developed in close cooperation with LSI development engineers within Sony in order to deliver on a tangible product that could encode at high speeds and with minimal power consumption.
Minidiscs with ATRAC format songs have, in the past, been supported on Eclipse brand car stereos.
Sony has all but dropped the ATRAC related codecs in the USA and Europe and their SonicStage powered ' Connect ' Music Service ( Sony's equivalent of iTunes ) on 31 March 2008.
The music format was originally based exclusively on ATRAC audio data compression, but the option of linear PCM digital recording was later introduced to attain audio quality comparable to that of a compact disc.
The digitally encoded audio signal on a MiniDisc has traditionally been data-compressed using the ATRAC format ( Adaptive TRansform Acoustic Coding ).
ATRAC was devised for MiniDisc so that the same amount of audio a CD can carry can fit on a disc far smaller than the CD ( which contains uncompressed 16-bit stereo linear PCM audio ).
ATRAC was also used on nearly all FLASH memory Walkman devices until the 8 series but is now only used in Sony's MiniDisc devices ( as of November 2008 ) as ATRAC is fundamental to the MiniDisc specification.
Sony's ATRAC codec differs from uncompressed PCM in that it is a psychoacoustic lossy audio data reduction scheme and is such that the recorded signal does not require decompression on replay.
Version 1 could only be copied on consumer equipment three or four times before artifacts became objectionable ( the ATRAC on the recording machine attempts to data reduce the already reduced signal ).
The latest versions of Sony's ATRAC are ATRAC3 and ATRAC3plus, both of which are true lossy compression schemes and both require decompression on replay.
In May 2004, a series of double-blind listening tests ( as reported on Slashdot ) suggested that Musepack and Ogg Vorbis ( which was the 1. 1 " aoTuV " fork at the time ) were the two best available codecs for high-quality audio compression at bitrates around 128kbit / s, beating MP3, AAC, WMA, and ATRAC.
In 2005, Sony released its second-generation Hi-MD devices offering native support for the popular MP3 format ( earlier, SonicStage would transcode MP3 files to ATRAC format before recording on the disc ).
* Sony PlayStation Portable supports gapless with ATRAC file formats ( Tested on 5. 00 M33-3 firmware )
It is also common on mid-to-high end portable voice recorders, which record to formats such as MP3 or ATRAC.
ATRAC and MiniDisc
MiniDisc was the first commercial product to incorporate ATRAC in 1992.
ATRAC allowed a relatively small disc like MiniDisc to have the same running time as CD while storing audio information with minimal loss in perceptible quality.
Other MiniDisc manufacturers such as Sharp and Panasonic also implemented their own versions of the ATRAC codec.
The PASC compression scheme was believed to give better quality audio than the 5: 1 compression used by ATRAC in the original MiniDisc, but not as good as the uncompressed DAT, although both Philips and Sony stated the difference was imperceptible to listeners ' ears ( like MP3 or AAC files today ).
ATRAC and is
The product affected with this transition is NW-A8XX Series, which was actually released twice, the version with ATRAC and the one without.
Adaptive Transform Acoustic Coding ( ATRAC ) is a family of proprietary audio compression algorithms developed by Sony.
Years later ATRAC was improved and is generally considered better than earlier versions at similar bitrates.
This is reflected in the design of the ATRAC codecs, which tend to emphasize processing smaller numbers of samples at a time to save memory at the cost of compression efficiency and additional multiplies.
However, as Sony only pushed ATRAC compatibility in Sony Ericsson Walkman series phones in the Japanese market, it is not supported in GSM / UMTS market phones.
Quality is generally transparent for many people ( meaning that it is not possible to tell an ATRAC encoding from the source ).
However, as ATRAC is a hybrid subband-MDCT codec that is algorithmically very similar to MP3, any advantage is probably exaggerated.
Unfortunately, due to lack of transparency in ATRAC encoder versioning, it is not known if the ATRAC3 encoder tested was optimal, and subsequent investigation was inconclusive.
This codec is used in Sony Hi-MD Walkman devices ( e. g., " Hi-LP and Hi-SP "), Network Walkman players, Memory Stick players, VAIO Pocket, PS3 and PSP console, and ATRAC CD players.
As in previous ATRAC versions, gain control is used to control preecho rather than variable sized transforms, although different MDCT windows are apparently possible.
ATRAC Advanced Lossless ( AAL ) is the latest update to the codec family.
ATRAC Advanced Lossless is widely supported in older Walkman players and SonicStage version 4 or later.
Early version players are guaranteed to play later version ATRAC audio because, as stated, there is no processing required for replay.
As a result of these advantages, the MDCT is employed in most modern lossy audio formats, including MP3, AC-3, Vorbis, Windows Media Audio, ATRAC, Cook, and AAC.
ATRAC and use
Furthermore, compared to newer formats such as Windows Media Audio which use a simple MDCT rather than a hybrid, ATRAC3 must perform an additional and computationally expensive inverse-QMF, although the hybrid system does significantly reduce memory usage, which was likely a factor given the limited memory available when ATRAC was originally developed.
As Sony engineers became more actively involved in the project, the design of the SDDS format evolved toward a more robust implementation, including the use of 5: 1 ATRAC data compression, extensive error detection and correction, and most critically redundancy.
ATRAC and ).
* Formats with lossless compression, such as FLAC, Monkey's Audio ( filename extension APE ), WavPack ( filename extension WV ), TTA, ATRAC Advanced Lossless, Apple Lossless ( filename extension m4a ), MPEG-4 SLS, MPEG-4 ALS, MPEG-4 DST, Windows Media Audio Lossless ( WMA Lossless ), and Shorten ( SHN ).
Today MiniDiscs can hold data files as well as music, with the ability to record and reproduce audio in CD-quality ( without ATRAC lossy compression ).
Contrary to most Walkman lines, Sony Ericsson Walkman Phones did not support Sony's proprietary audio format, ATRAC ( with all of its variants, except certain Japanese models supporting ATRAC ).
This completely eliminates compression artifacts that occur when recording directly to lossy audio formats such as Sony's ATRAC, or other formats like MP3, AAC, Windows Media Audio ( WMA ).
on and MiniDisc
Initially the MiniDisc was comparable to a miniaturised CD, capable of storing up to 74 minutes of near CD-quality audio on a disc roughly two-thirds the size of a CD.
The first unit on the market, the MZ-1 was relatively large and unpocketable, but following model, MZ-R2, and subsequent MD Walkmans are quite compact, with today's MiniDisc Walkmans not much larger than the discs themselves.
The addition of MDLP ( MiniDisc LongPlay ) codec allowed up to 4 times the amount of music to be stored on one MiniDisc, at the sacrifice of some sound quality.
It allows 324 minutes to be recorded on an 80 minute MiniDisc, with the same padding required as LP2.
The initial low uptake of MiniDisc was attributed to the small number of pre-recorded albums available on MD as a relatively small number of record labels embraced the format.
Hi-MD units allow the recording and playback of audio and data on the same disc, and are compatible ( both audio and data ) with standard MiniDisc media.
A buffer of at least six seconds is required on all MiniDisc players, be they portable or stationary full-sized units.
In 2000, Sony announced MDLP ( MiniDisc Long Play ), which added new recording modes based on a new codec called ATRAC3.
) to be stored on a Hi-MD formatted MiniDisc.
This allows for storage capacity of around 340MB on a standard MiniDisc and approx.
Sony decided to create the entirely new MiniDisc format ( based on their experience with magneto-optical recording and Compact Disc ) while Philips decided on a tape format that was compatible with their earlier analog Compact Cassette format.
To record a standard MiniDisc the writer uses an infrared laser to heat a spot of ferromagnetic material on the disc to above its Curie point, then it is magnetised by a recording head as it cools.
Today, with the vinyl record no longer being used as the primary form of distribution, the term " album " can still be applied to any sound recording collection, such as those on compact disc, MiniDisc, Compact audio cassette, and digital or MP3 albums.
On 30 October 2000, the album was released on MiniDisc.
* PCM mode allows 94 minutes ( 1 hour 34 min ) of lossless CD-quality audio to be recorded to a 1 GB Hi-MD disc ( or 28 minutes on a standard 80-minute MiniDisc recorded in Hi-MD mode ).
* Hi-SP allows seven hours and fifty-five minutes ( 7h: 55m ) of audio to be recorded on a 1 GB Hi-MD ( or 2h: 20min on a standard 80-minute MiniDisc recorded in Hi-MD mode ).
* Hi-LP allows 34 hours on a 1 GB Hi-MD ( or 10 hours 10 minutes on a standard 80-minute MiniDisc recorded in Hi-MD mode ).
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