Patent ID: 7839933

Claim:
A method of decoding video using a video decoder, the method comprising: with the video decoder, reading an indication from a compressed video bit stream whether a video sequence encoded in the bit stream contains at least some interlaced video content; with the video decoder, reading one or more coded size syntax elements from the bit stream, the one or more coded size syntax elements indicating a coded height of plural frames in the video sequence; if the video sequence contains at least some interlaced video content, with the video decoder, for each of the plural frames: reading a mode syntax element for the frame from the bit stream, the mode syntax element indicating one of plural coding modes for the frame, the plural coding modes including: coded in the bit stream as a frame of progressive video, coded in the bit stream as a frame of interlaced video, and coded in the bit stream as two separate fields of interlaced video; and decoding video content of the frame, wherein the frame has a macroblock-aligned vertical size that depends on the coding mode of the frame, and wherein depending on the coding mode the macroblock-aligned vertical size can vary between the plural frames that have the coded height of the plural frames; and otherwise, with the video decoder, decoding the video content of the plural frames in the video sequence.