1. A method for computing an inverse discrete cosine transform by using a number of non-zero coefficients and an associated function mapping method based on video compression standard syntax cues, the method comprising the steps of: generating a set of reduced complexity implementation candidates for the inverse discrete cosine transform; using video compression standard syntax cues to obtain the number of non-zero coefficients for the inverse discrete cosine transform; and mapping the number of non-zero coefficients to a corresponding reduced complexity implementation candidate inverse transformation.