Compression coding and compression decoding of video signals

A method of compression decoding a compressed bit stream comprising a plurality of compressed video pictures,

• wherein each of the compressed video pictures is a primary picture from a primary video signal or a secondary picture from one or more secondary video signal(s), the pictures from the primary video signal and the or all of the secondary video signal(s) being in an alternating sequence in picture display order of the received compressed bit steam,
• wherein the compression decoding method comprises the steps:
• identifying received compressed pictures as a primary picture or a secondary picture, and
• compression decoding received compressed pictures dependent upon the identification of the received compressed picture as a primary picture or a secondary picture.

A decoder for compression decoding a compressed bit stream comprising a plurality of compressed video pictures,

• wherein each of the compressed video pictures is a primary picture from a primary video signal or a secondary picture from one or more secondary video signal(s), the pictures from the primary video signal and the or all of the secondary video signal(s) being in an alternating sequence in picture display order of the received compressed bit stream,
• wherein the compression decoder comprises:
• source identifier for identifying received compressed pictures of the received bit stream as primary picture or secondary picture;
• and
• compression decoder, coupled to the source identifier, for compression decoding received compressed pictures dependent upon the identification of the received compressed picture as a primary picture or a secondary picture