US 8,509,306 B2 · Video frame encoding and decoding

Abstract

A video frame arithmetical context adaptive encoding and decoding scheme is presented which is based on the finding, that, for sake of a better definition of neighborhood between blocks of picture samples, i.e. the neighboring block which the syntax element to be coded or decoded relates to and the current block based on the attribute of which the assignment of a context model is conducted, and when the neighboring block lies beyond the borders or circumference of the current macroblock containing the current block, it is important to make the determination of the macroblock containing the neighboring block dependent upon as to whether the current macroblock pair region containing the current block is of a first or a second distribution type, i.e., frame or field coded.

An apparatus 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 bottom macroblock, the apparatus comprising:

means for deciding, for each macroblock pair region, as to whether the respective macroblock pair region is of a frame coded or a field coded distribution type;
means for 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;
means for pre-coding the video signal into a pre-coded video signal, including motion prediction of the macroblocks in units of partitions thereof to obtain, for each macroblock, a syntax element specifying, for a respective macroblock, a difference between a motion vector component and a prediction of the motion vector component;
means for determining, for the syntax element of a current macroblock associated with a current macroblock pair region of the macroblock pair regions,
a neighboring macroblock to the left of the current macroblock at least based upon as to whether the current macroblock pair region is of the frame or field coded distribution type such that
if the current macroblock pair region is of the field coded distribution type,
the neighboring macroblock to the left of the current macroblock is determined to be a bottom macroblock of a macroblock pair region to the left of the current macroblock pair region, if the macroblock pair region to the left is also of the field coded distribution type and the current macroblock is the bottom macroblock of the current macroblock pair region, and
the neighboring macroblock to the left of the current macroblock is determined to be a top macroblock of the macroblock pair region to the left of the current macroblock pair region, if the macroblock pair region to the left is of the frame coded distribution type, or if the macroblock pair region to the left is of the field coded distribution type with the current macroblock being the top macroblock of the current macroblock pair region, and
if the current macroblock pair region is of the frame coded distribution type,
the neighboring macroblock to the left of the current macroblock is determined to be the bottom macroblock of the macroblock pair region to the left of the current macroblock pair region, if the macroblock pair region to the left is also of the frame coded distribution type and the current macroblock is the bottom macroblock of the current macroblock pair region, and
the neighboring macroblock to the left of the current macroblock is determined to be the top macroblock of the macroblock pair region to the left of the current macroblock pair region, if the macroblock pair region to the left is of the field coded distribution type, or if the macroblock pair region to the left is of the frame coded distribution type with the current macroblock being the top macroblock of the current macroblock pair region and;
a neighboring macroblock to the top of the current macroblock at least based upon as to whether the current macroblock pair region is of a frame or field coded distribution type such that
if the current macroblock pair region is of the frame coded distribution type the neighboring macroblock to the top of the current macroblock is determined to be
a top macroblock of the current macroblock pair region if the current macroblock is the bottom macroblock of the current macroblock pair region, and
a bottom macroblock of the macroblock pair region to the top of the current macroblock pair region if the current macroblock is the top macroblock of the current macroblock pair region,
if the current macroblock pair region is of the field coded distribution type and the current macroblock is the top macroblock of the current macroblock pair region, the neighboring macroblock to the top of the current macroblock is determined to be
the bottom macroblock of the macroblock pair region to the top of the current macroblock pair region, if the macroblock pair region to the top of the current macroblock pair region is of the frame coded distribution type,
the top macroblock of the macroblock pair region to the top of the current macroblock pair region, if the macroblock pair region to the top of the current macroblock pair region is of the field coded distribution type,
if the current macroblock pair region is of the field coded distribution type and the current macroblock is the bottom macroblock of the current macroblock pair region, the neighboring macroblock to the top of the current macroblock is determined to be the bottom macroblock of the macroblock pair region to the top of the current macroblock pair region;
means for assigning one of at least two context models to the current syntax element of the current macroblock based on a pre-determined attribute of the neighboring macroblock to the left of the current macroblock and the neighboring macroblock to the top of the current macroblock, wherein each context model is associated with a different probability estimation;
and
means for arithmetically encoding the syntax element of the current macroblock into a coded bit stream based on the probability estimation with which the assigned context model is associated.

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Video frame encoding and decoding

Life of this patent

Video frame encoding and decoding

Life of this patent

Abstract

Claims11