Dynamically adaptive bitrate streaming

An apparatus for receiving and decoding an encoded data stream, the apparatus comprising:

• a processor configured to control streaming of an encoded data stream;
• a communications port configured to communicate with a source of the encoded data stream;
• a buffer configured to buffer segments of the encoded data stream;
• and
• a codec arranged to decode the buffered segments of the encoded data stream;
• wherein each segment of the encoded data stream is arranged in hierarchical layers comprising a plurality of segment units including a base layer segment and one or more enhancement layer segments, the base layer segment being decodable to a base level of reproduction quality, and the one or more enhancement layer segments, together with the base layer segment, being decodable to enhanced levels of reproduction quality;
• the processor being configured to cause the apparatus to:
• receive the encoded data stream through the communications port for a prescribed time period, the apparatus having derived and having pre-determined the prescribed time period for buffering the received data stream, the prescribed time period having been derived at least in part using a bandwidth of a communication link from which the data stream is received, a playback time of the data stream, and an amount of data in the data stream, and the encoded data stream having been created using the prescribed time period;
• buffer the entire base layer segment, all of a portion of a first enhancement layer segment that was received during the prescribed time period, and all of any additional enhancement layer segment portions that was received during the prescribed time period;
• transfer to a decoder for decoding the entire buffered base layer segment, the all of a portion of the first enhancement layer segment that was received during the prescribed time period, and the all of the any additional enhancement layer segment portions that was received during in-the prescribed time period.

A computer-readable hardware storage device having instructions recorded thereon which, when executed, causes a computer to perform a method of buffering, at a client device, a segment of an encoded data stream, the segment being arranged in hierarchical layers comprising a plurality of segment units including a base layer segment and one or more enhancement layer segments, the base layer segment being decodable to a base level of reproduction quality, and the one or more enhancement layer segments, together with the base layer segment, being decodable to enhanced levels of reproduction quality, the method comprising the steps of:

• receiving at the client device the segment of the encoded data stream within a prescribed time period, the client device having derived and having pre-determined the prescribed time period for buffering the received segment, the prescribed time period having been derived at least in part using a bandwidth of a communication link from which the segment is received, a playback time of the segment, and an amount of data in the segment, and the encoded data stream having been created using the prescribed time period;
• buffering the entire base layer segment, all of a portion of a first enhancement layer segment that was received during the prescribed time period, and all of any additional enhancement layer segment portions that was received during the prescribed time period;
• transferring to a decoder for decoding the entire base layer segment, the all of a portion of the first enhancement layer segment that was received during the prescribed time period, and the all of the any additional enhancement layer segment portions that was received during the prescribed time period.