Sonic Blue Volt SP250 User Manual page 33

Glossary
AAC
Advanced Audio Coding (AAC) is one of the audio compression formats defined by the MPEG-2 specification.
AAC used to be called NBC (Non-Backward-Compatible), because it is not compatible with the MPEG-1 audio
formats. AAC may eventually replace MP3 since it offers better sound quality and greater file compression.
Bitrate, file compression
Bitrate denotes the average number of bits that one second of audio data will consume. The size of a digital
audio file is determined by the bitrate used when encoding the file. The higher the bitrate used, the higher the
sound quality and the larger the file size. For example, for MP3s a bitrate of 128k is usually very close to CD
quality, and takes up about 1MB per minute of music. At a 64k bitrate, the MP3 sound quality is similar to that
of an FM radio signal, but you may get around two minutes of music in that same 1MB of storage space.
Codec
Depending on the context and kind of technology involved, codec may be defined in two ways.
In telecommunications, a codec is usually a "coding/decoding" chip used to translate between digital and analog
transmissions. A modem uses one to interpret incoming analog signals and converts the digital data stream
coming from the computer into analog.
A codec is also defined as a compression/decompression algorithm. Codecs are used to shrink large files or
data streams, often for efficient transmission over a network, and then decode them when they are displayed.
The RioVolt supports the following digital audio file codecs:
• MP3
• WMA
DRM, security
Digital Rights Management (DRM) technologies protect copyright ownership of digital information. DRM
became an issue with the rise of MP3 technology and Internet distribution of music. DRM platforms serve as a
security "wrapper" around digital audio supporting Internet distribution while at the same time protecting and
managing rights related to that digital information.
Encode, "Rip" (a CD)
Encoding, or "ripping", refers to converting an audio file from a CD-ROM into a compressed digital audio
format, such as MP3 or WMA, that may be played on the RioVolt, on the computer, or on a portable Rio Digital
Audio Player.
ID3 Tag
This is the part of the encoded MP3 file that contains information about the digital music file such as song title,
artist, album title, bitrate encoding, time duration of track, and so on.
Glossary
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