A software-defined media platform having one or more media processing units that may be dynamically instantiated, interconnected and configured according to changes in demand, resource availability, and other parameters affecting system performance relative to demand. In one example media processing method, a source media stream may be received via multicast or unicast. The source media stream may be processed into one or more levels of work product segments having different media characteristics by a plurality of transcoding processing units, as needed. One or more levels of work product segments, or the source media stream, may be packaged (e.g., including resegmenting) into final work product segments having select media characteristics, which may be uploaded to a cloud storage unit for delivery to end users.