Patent ID: 8588305

Claim:
An apparatus for interpolation, comprising: a first unit, for interpolating input data, that includes both a vertical filter for performing vertical filtering and a horizontal filter for performing horizontal filtering, wherein the vertical filter is configured to evaluate a merged equation comprising a 4-tap filter equation, a 6-tap filter equation, and an 8-tap filter equation by accepting inputs for a 4-tap filter equation, a 6-tap filter equation, and an 8-tap filter equation; a second unit for interpolating input data; a filter indicator for providing information to the first unit and the second unit; and an output unit for multiplexing and averaging output from the first unit and the second unit, wherein the vertical filter comprises a first stage configured to receive the inputs and generate a set of first stage signals in response to the interpolation inputs, a second stage configured to receive the set first stage signals and generates a set of second stage signals in response, a third stage configured to receive the set of second stage signals and generate a set of third stage signals in response, and a fourth stage configured to receive the set of third stage signals and generate a common virtual filter output in response, wherein the fourth stage includes a fourth stage multiplexer configured to select between an unshifted fourth stage signal, a three-place-shifted fourth stage signal, a five-place-shifted fourth stage signal, and a six-place-shifted fourth stage signal.