Motion Vector Prediction

摘要

A system includes motion vector prediction circuitry that generates motion vectors for pixel groups and pixel subgroups within the pixel groups. For a current pixel group within the currently processed picture, the motion vector prediction circuitry selects a target reference picture. Without first translating the current pixel group in accord with an offset vector, the motion vector prediction circuitry initiates generation of a default motion vector for the current pixel group. Responsive to the selected target reference picture, the motion vector prediction circuitry generates the offset vector. The motion vector prediction circuitry translates the current pixel group in accord with offset vector and determines motion vectors for pixel subgroups of the current pixel group based on the translated position of the current pixel group.

主权项

1. A device comprising:
buffer circuitry configured to store:
a current picture comprising a current pixel group comprising a pixel subgroup;a target reference picture comprising a co-located pixel group that includes a spatial position in the target reference picture occupied by the current pixel group in the current picture; anda reference vector picture; candidate selection circuitry in data communication with the buffer circuitry, the candidate selection circuitry configured to:
without first translating the current pixel group in accord with an offset vector, determine the co-located pixel group has an assigned candidate motion vector;determine a default motion vector from the assigned candidate motion vector of the co-located pixel group; and subgroup vector selection circuitry in data communication with the buffer circuitry and the candidate selection circuitry, the subgroup vector selection circuitry configured to:
determine that a spatiotemporal neighbor pixel group has an assigned reference vector that indicates a predictive relationship that points to the reference vector picture;determine a ratio of a first duration between the current picture and the reference vector picture to a second duration between the current picture and the target reference picture;scale the reference vector in accord with the ratio to determine the offset vector; andafter translating the current pixel group in accord with the offset vector, determine whether to use the default motion vector or a subgroup motion vector different from the default motion vector for the pixel subgroup.