re x oversampling cd player in article mcmahanc v mkj netcom com mcmahan netcom com dave mc mahan writes in a previous article kolstad cae wisc edu joel kolstad writes in article hcbc un l dd netcom com hcb netcom com h c bowman writes i just bought a new portable cd player for the office and i notice that it proudly proclaims times oversampling on the box the data is only ever read once barring mistracks and such of course and eventually gets turned into khz bit two channel data oversampling takes two discrete data points and interpolates n points between them for n times oversampling when i asked people said that the interpolation was not simply linear interpolation but significantly more complicated you are quite correct in your understanding in case you care the filtering method uses an fir finite impulse response filter i d guess that cd makers use the same kind of method anybody out there know the real answer typical in the old x oversampling units was a thirteen tap fir implemented as a dedicated hardware addition circuit at this kind of speed slow by digital standards such an adder is much less expensive than analog components of comparable precision i gleaned this information from a hardware manual for an old cd player design where one would find similar info for a particular cd the digital filter is an interesting component from my point of view i have no idea the digital filter is a kind of interpolation scheme read a book on numerical analysis to see just how broad the term interpolation is john whitmore
