Simplified inter-layer motion prediction for scalable video coding

Method, as part of a scalable video coding method in a scalable video coder or of a scalable decoding method in a scalable video decoder, for determining for a high layer macroblock that uses inter-layer prediction a partitioning of said macroblock in partitions comprising the following steps:

• In the scalable video coder or in the scalable video decoder, dividing said high layer macroblock in non-overlapping high layer blocks of a predefined size;
• determining a corresponding base layer pixel for one pixel, called reference pixel, of each high layer block;
• identifying, for each reference pixel, a base layer macroblock to which said corresponding base layer pixel belongs, a base layer partition to which said corresponding base layer pixel belongs in said identified base layer macroblock, a base layer sub-partition to which said corresponding base layer pixel belongs in said identified base layer partition if said base layer sub-partition exists;
• deriving, for each of said high layer block, a single value, called PartInfo value, as follows:
• setting PartInfo value to a predefined negative value if said identified base layer macroblock is INTRA coded;
• and
• computing said PartInfo value on the basis of the identified base layer macroblock, identified base layer partition and identified base layer sub- partition if said sub-partition exists, otherwise;
• and
• determining a partitioning of said high layer macroblock in macroblock partitions by comparing between them said PartInfo values associated with each of said high layer blocks.