The previous discussion was based on the use of digital delay lines with integer sample delay lengths. In many contexts, it is necessary to compute the output of a delay line at fractional delay-line lengths.
While signal values in a delay line are stored at integer multiples of the sample period , it is possible to apply interpolation techniques to approximate values between those in memory.
The most common interpolation techniques used in conjunction with delay lines are linear interpolation and allpass interpolation.
The MSP tapout˜ object provides interpolation when a signal input is connected to its left inlet. Note that the connection from a tapin˜ to a tapout˜ object is symbolic ... no actual signal is transmitted via that patchcord.