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Appendix
MP3 (MPEG-1 Audio Layer 3)
The MPEG Audio standard is a standard for compression of audio information. Layer 1 can
obtain a compression ratio of 1/4, Layer 2, 1/8 and Layer 3, 1/10. Since high sound quality
approaching that of a music CD can be obtained, this format is convenient for compact
playback devices (portable players, etc.) and for distribution over the Internet.
MMC (MultiMediaCard)
This is the next generation of ultra-compact, ultra-light digital media (storage media). It is
mainly being given attention as a media for MultiMedia devices. Besides the HyperHyde, it is
used for digital cameras, etc. Since it uses Removable technology, it can have a large capacity
and be flexible, and can be handled with the ease of handling of MD or cassette tapes.
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Encode / Decode
Encoding is to convert data to code in accordance with a fixed standard, or it specifies software
or hardware that accomplishes this task. Decoding is to return the encoded data to their original
form.
Sampling Rate
This is the interval time at which sampling is carried out. Units are seconds. The number of
times sampling is done per second is the Hz (Hertz) unit, the greater the sampling rate, etc., the
more accurate data becomes, but at the same time, the volume of data increases . Generally,
the sampling rate for a music CD is 44 kHz.
Bit Rate
This is the speed at which 1 bit is transferred.
Explanation of Terms
