A bit of Digital Blah-blah |
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Digital audio picks-up several samples per second on you original signal, at a frequency called the sampling frequency.
The most common are the 44.1 kHz of the CD format and the 48 kHz of several other formats, including the ADAT, the DA-88, and professional multi-track tape machines, etc...
Each sample is then converted to a number, expressed as a certain number of bits, which is refered to as the resolution of the converter.
The standard resolution is still 16 bits, even though more and more machines work on a resolution of 20, and even 24 bits.
To evaluate the computer memory required by one minute of digital audio, all you have to do is follow these simple calculations :
GENERAL FORMULA |
EXAMPLE |
Sampling Frequency x Resolution x 60 seconds |
Recording to a Direct to Disk at 48 kHz, 24 bits : 48 000 x 24 x 60 = 69120000 bits
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The number you get is the number of bits. This unit is seldom used in the computer world. They prefer to speak in bytes (groups of 8 bits). Let's divide that number by 8 to get the number of bytes... |
69120000 / 8 = 8640000 Bytes |
This number is very big, let's divide it by 1024 to get Kilo-Bytes (why 1024 ? It's a long story, too long to explain here.)... |
8640000 / 1024 = 8437,5 kB |
Since that number is still quite big, let's go to expressing it in Mega-Bytes, by dividing, again, by 1024... |
8437,5 / 1024 = 8,2397460938 MB |
All you have to do is round that number to make it a bit more human, no computer is going to rule my life !!! |
8,3 MB |
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