1. A machine-implemented method, comprising: receiving a scalable encoded bitstream comprising scalable encoded media data and values of non-media-type-specific scalability attribute variables defining different adaptation points of the scalable encoded media data; obtaining receiving attributes for a destination of an outbound version of the scalable encoded bitstream, wherein ones of the receiving attributes define explicit constraints on the outbound version of the scalable encoded bitstream in terms of respective functions of ones of the scalability attribute variables; determining values of adaptation measures from respective evaluations of the functions based on the values of the ones of the scalability attribute variables; ascertaining a set of one or more candidate ones of the adaptation points of based on imposition of the constraints on the determined values of the adaptation measures; selecting an adaptation point from the set of candidate adaptation points without regard to the scalable encoded media data; and transcoding the scalable bit stream in accordance with the selected adaptation point to produce the outbound version of the scalable encoded bitstream.