●A/D Conversion
“A/D conversion” refers to changing analog code into digital code. Conversely, restoring digital code to analog code is referred to as “D/A conversion.”
Analog data such as music is divided and extracted at set intervals.
Reference
Decode
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The information extracted during sampling is expressed using numeric
values (bits).
Quantization
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“Decode” refers to restoring original
data by converting encoded data according to specified rules. Software
which performs this operation is known
as a “decoder.”
Reference
Sampling rate
Basic theory
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“Encode” refers to converting data according to specified rules. Software
which performs this operation is known
as an “encoder.”
Chapter 7
Sampling
Reference
Encode
“Sampling rate” refers to the number of
times analog data is measured within
one second. Also referred to as “sampling frequency,” this unit is expressed
using “Hz.” The greater the sampling
rate, the better the sound quality when
the digital data is replayed.
Reference
Bits are converted to data following specific guidelines. For example,
they are expressed through a radix conversion, where the data is
changed from decimal numbers to binary numbers.
Encoding
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Sampling and quantization
While analog code consists of consecutively grouped data, digital code is comprised of data that is divided separately.
By shortening the sampling interval and
increasing the level of quantization to
search for more exact values, it is possible to approach the quality of the analog data during A/D conversion.
• The longer the sampling interval, the
lower the quantization level
Coded data is converted into digital data.
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Coded digital
display
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• The shorter the sampling interval, the
higher the quantization level
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