A method for delivering an incomplete response to a media file request from a server to a client, comprising: receiving a segment request in the server from the client, wherein the segment request indicates whether the client is capable of using an incomplete segment; determining, in the server, whether a full segment associated with the segment request is available at the server; determining, in the server, based on the segment request, whether the client is capable of using an incomplete segment in response to the full segment associated with the segment request not being available at the server; and sending from the server to the client an incomplete segment in a response message including: an indication that the response message includes the incomplete segment; an indication of a portion of a requested segment that is included in the incomplete segment included in the response message, wherein the indication of the portion of the requested segment that is included in the incomplete segment comprises an indication of a byte range within the requested segment that is included in the incomplete segment; the method characterised by the response message further including an indication of one or more access positions for the incomplete segment in response to determining that the client is capable of using an incomplete segment, wherein the one or more access positions identify one or more points within the incomplete segment at which to begin parsing to decode the incomplete segment. receiving a segment request in the server from the client, wherein the segment request indicates whether the client is capable of using an incomplete segment; determining, in the server, whether a full segment associated with the segment request is available at the server; determining, in the server, based on the segment request, whether the client is capable of using an incomplete segment in response to the full segment associated with the segment request not being available at the server; and sending from the server to the client an incomplete segment in a response message including: an indication that the response message includes the incomplete segment; an indication of a portion of a requested segment that is included in the incomplete segment included in the response message, wherein the indication of the portion of the requested segment that is included in the incomplete segment comprises an indication of a byte range within the requested segment that is included in the incomplete segment; an indication that the response message includes the incomplete segment; an indication of a portion of a requested segment that is included in the incomplete segment included in the response message, wherein the indication of the portion of the requested segment that is included in the incomplete segment comprises an indication of a byte range within the requested segment that is included in the incomplete segment; the method characterised by the response message further including an indication of one or more access positions for the incomplete segment in response to determining that the client is capable of using an incomplete segment, wherein the one or more access positions identify one or more points within the incomplete segment at which to begin parsing to decode the incomplete segment.