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| MP3 >< iPod Touch >< iPod
Nano >< Music >< Movies >< Singers > |
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| MP3 |
| MPEG-1 Audio Layer 3, more commonly
referred to as MP3, is a digital audio encoding format using a form of
lossy data compression. It is a common audio format for consumer audio
storage, as well as a de facto standard encoding for the transfer and playback
of music on digital audio players. MP3 is an audio-specific format that
was designed by the Motion Pictures Expert Group. The group was formed
by several teams of engineers at Fraunhofer IIS in Erlangen, Germany, AT&T-Bell
Labs in Murray Hill, NJ, USA, Thomson-Brandt, and CCETT as well as others.
It was approved as an ISO/IEC standard in 1991. |
| The use in MP3 of a lossy compression
algorithm is designed to greatly reduce the amount of data required to
represent the audio recording and still sound like a faithful reproduction
of the original uncompressed audio for most listeners, but is not considered
high fidelity audio by audiophiles. An MP3 file that is created using the
mid-range bit rate setting of 128 kbit/s will result in a file that is
typically about 1/10th the size of the CD file created from the original
audio source. An MP3 file can also be constructed at higher or lower bit
rates, with higher or lower resulting quality. The compression works by
reducing accuracy of certain parts of sound that are deemed beyond the
auditory resolution ability of most people. This method is commonly referred
to as perceptual coding.[1] It internally provides a representation of
sound within a short term time/frequency analysis window, by using psychoacoustic
models to discard or reduce precision of components less audible to human
hearing, and recording the remaining information in an efficient manner.
This is relatively similar to the principles used by JPEG, an image compression
format. |
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