Patent ID: 8335263

Claim:
A method of processing a current field macroblock, comprising: determining reference picture index numbers in a reference picture list, the reference picture index numbers increasing for reference pictures having a decreasing display order with respect to a picture including the macroblock, the reference picture numbers increasing for reference pictures having an increasing display order with respect to the picture including the macroblock, and the reference picture index numbers of the reference pictures having a decreasing display order being greater than the reference picture index numbers of the reference pictures having an increasing display order; obtaining motion vector information for the current field macroblock obtaining a field reference picture index associated with the current field macroblock; selecting a frame reference picture based on a frame reference picture index and the reference picture index number; selecting a field reference picture having a parity different from a parity of the field macroblock if the field reference picture index is an odd value; and decoding the current field macroblock based on the motion vector information and the selected field reference picture.