Patent ID: 8149919

Claim:
A method of decoding a current field macroblock, comprising: obtaining a reference frame picture list including multiple reference frame pictures; determining a reference frame picture index of the multiple reference frame pictures in the reference frame picture list based on display order information for the multiple reference frame pictures, the reference frame picture index numbers being allocated to reference frame pictures having a greater display order than that of a picture including the current field macroblock in the display order, and the rest of the reference frame picture index numbers being allocated to reference frame pictures having a less display order than that of the picture including the current field macroblock in reverse order of the display order; obtaining a reference field picture index associated with the current field macroblock; determining a reference frame picture from the reference frame picture list based on the reference field picture index divided by 2 and the reference frame picture index; selecting a reference field picture for the macroblock based on the reference field picture index and the determined reference frame picture; and decoding the current field macroblock based on the selected reference field picture.