What does "warp" mean in DSP?
I've never really heard of "warp" regarding ADCs or DACs, but I imagine it's because the analog-to-digital (or vise versa) mapping function, which is supposed to be linear, a straight line, is curved slightly due to variation in parts.  I don't see how this would happen with sigma-delta ADCs or DACs (unless the summer at the input with the delta feedback is non-linear).  but with an R-2R DAC, if the R's aren't all perfectly the same, the digital-to-analog mapping function will not be a straight line.  For a flash ADC, if all of the resistors in the voltage divider line are not all perfectly equal, that analog-to-digital mapping function will also not be linear and would be "warped".

If, somehow, one can measure or determine the "warpness" of the mapping function, I suppose it can be compensated in the DSP software.