Delivering cacheable streaming media presentations

摘要

A smooth streaming system provides a stateless protocol between a client and server in which the server embeds incremental control information in media fragments. The server provides uniform media fragment responses to media fragment requests that are cacheable by existing Internet cache infrastructure. The smooth streaming system receives media data in fragments from one or more encoders, creates an index of each fragment, and stores the fragments. The server provides fragments to clients that contain metadata information describing the encodings available on the server and the encoding of the fragment. The server may also provide information within each fragment that allows the client to determine whether the client is requesting data too fast or too slow, so that the client can adapt its request rate to a cadence in tune with the rate at which the server is receiving encoder data.

主权项

1. A computer-implemented method for providing streaming media from a server to a client, the method comprising:
receiving a manifest request from the client; building a client manifest to satisfy the client request based on media fragments and encoder information the server has received, wherein the client manifest specifies one or more media fragments associated with a media event and wherein each media fragment is structured to be individually cacheable by a network cache server by providing a defined request format for each fragment for which any client using the defined format to request the fragment will receive the same response and wherein fragment requests for different encodings of the same streaming media map to the same point within a media presentation; providing the built client manifest to the client in response to the manifest request; receiving a fragment request from a client that identifies a particular media fragment; building an incremental manifest by retrieving manifest information that describes the requested media fragment, the incremental manifest further comprising information for one or more media fragments received by the server subsequent to building of the client manifest; sending a response to the client fragment request that includes the requested media fragment and the built incremental manifest; wherein the preceding steps are performed by at least one processor and wherein the server provides media fragments to multiple clients without storing state information regarding each of the clients.