| 摘要 |
In one aspect, an encoder/decoder receives information (1905) for four field motion vectors for a macroblock in an interlaced frame-coded, forward-predicted picture and processes the macroblock using the four field motion vectors. In another aspect, a decoder decodes skipped macroblocks of an interlaced frame. Skipped macroblocks use exactly one motion vector and have no motion vector differential information, and lack residual information. The skipped macroblock signal indicates one-motion-vector coding. In another aspect a decoder receives luma motion vector information for plural luma motion vectors for a macroblock and derives a chroma motion vector for each luma motion vector by performing at least one calculation on the luma motion vector information, maintaining a 1:1 ratio of chroma motion vectors to luma motion vectors for the macroblock. For example, the decoder receives four luma field motion vectors for a macroblock and derives four chroma motion vectors for the macroblock. |
