Patent ID: 7664177

Claim:
In a computing device that implements a video decoder, a method comprising: receiving, at the computing device that implements the video decoder, from a bit stream a field picture type indicator syntax element for a field mode interlaced video frame, the field picture type indicator syntax element indicating that a first field in the field mode interlaced video frame has a field picture type of intra-coded B-field, wherein having the field picture type of intra-coded B-field indicates: syntax elements of the first field follow I-field syntax according to which macroblocks of the first field are intra coded and lack motion-compensation prediction mode information at macroblock level in the bitstream, thereby reducing coding overhead for the macroblocks of the first field, and the first field is unusable as a reference field in motion compensation for any picture outside of the field mode interlaced video frame; and with the computing device that implements the video decoder, intra decoding the first field.