Method and apparatus for decoding an enhanced video stream

A method of decoding an enhanced video stream, the method comprising:

• receiving a multiplexed transport stream conveying, in a plurality of packetized elementary streams, base layer video access units and enhancement layer video access units, each access unit comprising a plurality of syntax structures,
• wherein said multiplexed transport stream conveys, with different respective program identifiers, the syntax structures of the base layer access units and remaining syntax structures other than those of the base layer access units, and
• wherein the remaining syntax structures comprise a delimiting syntax structure marking a boundary of video layer syntax structures of the access unit;
• demultiplexing the transport stream to create at least two program streams based on the different respective program identifiers;
• passing the syntax structures of the base layer access units to a base layer buffer;
• passing syntax structures of the enhancement layer access units to an enhancement layer buffer;
• outputting the syntax structures passed to the base layer buffer in a predetermined sequence;
• outputting the syntax structures passed to the enhancement layer buffer in a predetermined sequence;
• and
• recombining the sequences of syntax structures output by the base layer buffer and the enhancement layer buffer respectively to form a complete enhanced access unit, comprising base layer syntax structures and enhancement layer syntax structures in a predetermined sequence.