How can I do CD <=> DAT sample rate conversion?
Updated 9/13/99 CD players use a 44.1 kHz sample rate, whereas DAT uses a 48 kHz sample rate. This means that you must do sample rate conversion before you can get data from a CD player directly into a DAT deck. [From Ed Hall, edhall@rand.org:] For a start, look at Multirate Digital Signal Processing by Crochiere and Rabiner (see FAQ section 1.1). Almost any technique for producing good digital low-pass filters will be adaptable to sample-rate conversion. 44.1:48 and vice-versa is pretty hairy, though, because the lowest whole-number ratio is 147:160. To do all that in one go would require a FIR with thousands of coefficients, of which only 1/147th or 1/160th are used for each sample–the real problem is memory, not CPU for most DSP chips. You could chain several interpolators and decimators, as suggested by factoring the ratio into 3*7*7:2*2*2*2*2*5. This adds complexity, but reduces the number of coefficients required by a considerable amount. [From Lou Scheffer:] Theory of operation
