A video stream is provided to a set top box of a viewer to fulfill the viewer's request for a video on-demand service. The video stream is encoded at one of a plurality of encoding rates selected by a Service Quality Manager based on parameters defined for a service group, which in various embodiments may comprise the viewer, or the viewer along with other customers serviced by a single QAM. The parameters used for determining the encoding rate may involve currently allocated bandwidth, the viewer's service parameters, other customer's service parameters, and historical data regarding encoding rate selection data. The encoding rate used to encode a stream may be modified during streaming in response to other service requests. The encoding rate may be shifted based on anticipated service requests from other members in the service group.