Methods and systems are described for adaptively transmitting streaming data to a client. In one embodiment, the method comprises receiving, in a server, a request for a data asset from the client, transcoding at least a segment of the data asset according to initial transcoding parameters, transmitting a first fragment of the transcoded segment of the data asset from the server to the client over a communication channel, generating an estimate of a bandwidth of the communications channel at least in part from information acknowledging reception of at least the first fragment of the transcoded segment of the data asset by the client, generating adaptive transcoding parameters at least in part from an estimate of a bandwidth of the communications channel, the estimate generated at the server, transcoding a further segment of the data asset according to the adaptive transcoding parameters, and transmitting the further segment of the data asset.