Theoretical question about how CD's work


Theoretically, can the contents of a CD be printed out onto sheets of paper in 1’s & 0’s, re-entered digit by digit (say, by a generous helper monkey with an infinite lifespan) into some sort of program, and the same sound will be replicated? Just trying to understand how CD’s work (though I’ve been trying for 25 years and it still seems like magic to me).
sealrock

Showing 4 responses by marklings

Short answer: yes.

If you want to get a better grasp of the process you would need to understand the basic concepts of ANALOG and DIGITAL. Sampling is the process that takes you from Analog to Digital. You take a "sample" of an analog event and turn it into a number, a digit. This is sampling.

There are 2 key elemnts to how sampling is done: how often do you take the sample and how precisely you do that. The Red Book audio standard (the one CDs are made out of) calls for samples to be done 44.100 times a second and with a precision of 16 bits. So within those boudaries you can build an excat replica of the input signal by any mean, including the Monkey you mention. This is what would be called "bit perfect" in that the bits are exactly copied. The copy the monkey would have made would be absolutely non recognizable form the original and if played on the same playback system would sound 100% the same.

There are many misconceptins around, I'll mention a few:

QUITE The encoded data - the pits and lands do not actually represent digital data, not really UNQUOTE

Yes they absolutely do !

QUOTE The series of pits and lands, their various lengths and the transitions from pits to lands and lands to pits are converted to meaningful digital data downstream. So, since the lengths of pits and lands is variable precise timing is critical ... UNQUOTE

Precise timing is indeed critical in that the samples need to be payed back at exactly 44.1 KHz. But that is implicit in the standard, NOT HARDCODED in the digital domain !

BTW your it's an intersting question

You can start here:  https://en.wikipedia.org/wiki/Sampling_(signal_processing)

And spend more or less the rest of your life digging ! Enjoy !
Mark.
OK, simple question
How do you realize one bit is wrong ?
How do you know this zero is a good zero but that one is a bda one ?
8th note
The Flac file is exactly like any other file, a bunch of 0s and 1s. It is a "non lossy" compressed format, meaning that its size is smaller than the original but no information is lost. BTW an internet packet again is a stream of 0s and 1s !!! 
I for one do not believe any error correction is needed. You copy a file you get a perfect copy unless someone can show me why a copy of a Data file from a CD should be different from a copy of an audio file.
Differences may and will come up when you "render" that file. I.e. when you get back to the analog world via a DAC; that might be slightly different (the rendering I mean) from one DAC to another resulting in a slightly difrernt analog signal. Same digital input, different analog output.
OK so I learned something. Analog means distance and speed dependent. I am off this thread . . .