Patent ID: 8565304

Claim:
A method for encoding a video signal representing at least one video frame, with the at least one video frame being composed of picture samples, the picture samples belonging either to a first or a second field being captured at different time instants, the video frame being spatially divided up into macroblock pair regions, each macroblock pair region being associated with a top and a bottom macroblock, the method comprising the following steps being performed by an encoder: deciding, for each macroblock pair region, as to whether the respective macroblock pair region is of a first or a second distribution type; assigning, for each macroblock pair region, each of the pixel samples in the respective macroblock pair region to a respective one of the top and bottom macroblock of the respective macroblock pair region, in accordance with the distribution type of the respective macroblock pair region; pre-coding the video signal into a pre-coded video signal, the pre-coding comprising the sub-step of pre-coding a current macroblock of the top and bottom macroblock associated with a current macroblock pair region of the macroblock pair regions to obtain a current syntax element being an chroma prediction indicator indicating a type of spatial prediction used for chroma information of the current macroblock; determining, for the current syntax element, a neighboring macroblock at least based upon as to whether the current macroblock pair region is of a first or second distribution type; assigning one of at least two context models to the current syntax element based on an availability of the neighboring macroblock indicating as to whether the predetermined macroblock and the neighboring macroblock belong to the same slice of the video frame or to different slices of the video frame, a macroblock type indicator of the neighboring macroblock, specifying a macroblock prediction mode and a partitioning of the neighboring macroblock used for prediction, the neighboring macroblock being inter or intra coded in the coded bit stream, and a syntax element specifying, for the neighboring macroblock, a type of spatial prediction used for chroma information of the neighboring macroblock, wherein each context model is associated with a different probability estimation; and arithmetically encoding the syntax element into a coded bit stream based on the probability estimation with which the assigned context model is associated.