Apparatuses and methods for optimizing rate-distortion costs in a signal are disclosed herein. An apparatus may comprise a quantization block that may be configured to serially receive a plurality of coefficients and to generate a plurality of candidates for each of a plurality of coefficients. The quantization block may further be configured to generate a respective arc for each of the candidates having a respective rate and in accordance with the MPEG-2 coding standard. The quantization block may further be configured to identify which of the plurality of arcs has a minimum cost and provide a modified plurality of coefficients associated with the minimum cost arc.