In an adaptive steaming system, a media server for performing adaptive streaming on media contents sends to a client device a media presentation description (MPD) file including information specifying streaming adaptation parameters. The media server receives a request from the client device. The request includes a data object location indicator and a query string containing at least one of the values of the streaming adaptation parameters. After receiving the request, the media server selects a data object to be returned to the client device based on at least one of the data object location indicator and the query string and sends a response with the data object to the client device.