Systems and methods for performing motion vector prediction for video coding using motion vector predictor origins
Systems and methods for performing motion vector prediction for video coding are disclosed. A motion vector predictor is determined based at least in part on motion information associated with a selected motion vector predictor origin and offset values corresponding to a selected sampling point. The sampling point is specified according to a set of direction and distance on a sampling map for the motion vector predictor origin.
1. A method of deriving motion vector information for a coding block, the method including:
deriving a candidate set for a merge mode, wherein the candidate set includes a first motion vector predictor candidate at a first position and a second motion vector predictor candidate at a second position;
deriving a motion vector to be added to the candidate set by using a sum of the first motion vector predictor candidate and the second motion vector predictor candidate;
receiving an index syntax element used for indicating a predetermined motion vector predictor candidate in the candidate set and used for deriving the motion vector information;
receiving a distance index syntax element used to derive a distance in a set of distances;
receiving a motion distance syntax element used to derive a motion distance;
receiving a direction syntax element used to derive directions including a negative X direction, a positive X direction, a positive Y direction, or a negative Y direction;
deriving an offset value by using the direction syntax element and the motion distance; and
deriving the motion vector information by modifying the motion vector by using the offset value, wherein
the distance derived based on the distance index syntax element equal to a first value results in different values of the motion distance according to a value of the motion distance syntax element.
2. A device for deriving motion vector information for a coding block, the device comprising:
a processor, and
a memory associated with the processor; wherein the processor is configured to:
derive a candidate set for a merge mode, wherein the candidate set includes a first motion vector predictor candidate at a first position and a second motion vector predictor candidate at a second position;
derive a motion vector to be added to the candidate set by using a sum of the first motion vector predictor candidate and the second motion vector predictor candidate;
receive an index syntax element used for indicating a predetermined motion vector predictor candidate in the candidate set and used for deriving the vector information;
receive a distance index syntax element used to derive a distance in a set of distances;
receive a motion distance syntax element used to derive a motion distance;
receive a direction syntax element used to derive directions including a negative X direction, a positive X direction, a positive Y direction, or a negative Y direction;
derive an offset value by using the direction syntax element and the motion distance; and
derive the motion vector information by modifying the motion vector by using the offset value; wherein
the distance derived based on the distance index syntax element equal to a first value results in a different values of the motion distance according to a value of the motion distance syntax element.