This paper considers a coding scheme for data transmission over erasure channels which is also known as multiple description coding. The LMMSE prefilter method of Romano [1] is reviewed and generalized to allow three different operational modes of the prefilter. They include the possibility to decrease or increase the number of descriptions to be transmitted. We derive explicitly the Hessian matrix for an efficient calculation of the prefilter. We also study the properties of the distortion measure theoretically.