Method and device for obtaining motion vector of video image
A video processing method includes performing or skipping following processing based on whether a size of a coding unit is not smaller or is smaller than 8×8. The processing includes dividing the coding unit into sub-blocks each having a fixed size of 8×8, scanning a left neighboring block and determining a reference motion vector of the coding unit, determining a related reference block of a sub-block in the co-located reference image according to the reference motion vector, determining a scaling factor of a motion vector of the related reference block, scaling the motion vector of the related reference block using the scaling factor, determining motion information of the sub-block according to the scaled motion vector, and performing prediction for the coding unit according to the motion information.
1. A video processing method comprising:
in response to a size of a coding unit being not smaller than 8×8, performing processing including:
dividing the coding unit into several sub-blocks each having a fixed size of 8×8;
obtaining M candidate motion vectors, M being an integer larger than 1, and the M candidate motion vectors including a motion vector of a left neighboring block of the coding unit;
scanning N candidate motion vectors of the M candidate motion vectors, N being an integer smaller than M, and:
in response to a reference frame pointed to by one candidate motion vector of the N candidate motion vectors being same as a co-located reference image of the coding unit, determining the one motion vector as a reference motion vector of the coding unit; and
in response to none of the N candidate motion vectors pointing to a reference frame same as the co-located reference image of the coding unit, determining a default value (0, 0) as the reference motion vector of the coding unit;
determining a related reference block of one of the sub-blocks of the coding unit in the co-located reference image of the coding unit according to the reference motion vector of the coding unit;
in response to a motion vector of the related reference block of the one of the sub-blocks pointing to a short-term reference image:
determining a scaling factor of the motion vector of the related reference block of the one of the sub-blocks according to:
a temporal distance between a reference image pointed to by the motion vector of the related reference block of the one of the sub-blocks and the co-located reference image of the coding unit, and
a temporal distance between the co-located reference image of the coding unit and an image containing the coding unit;
scaling the motion vector of the related reference block of the one of the sub-blocks using the scaling factor; and
determining motion information of the one of the sub-blocks according to the motion vector after being scaled;
in response to the motion vector of the related reference block of the one of the sub-blocks pointing to a long-term reference image:
setting the scaling factor of the motion vector of the related reference block of the one of the sub-blocks to 1;
scaling the motion vector of the related reference block of the one of the sub-blocks using the scaling factor; and
determining the motion information of the one of the sub-blocks according to the motion vector after being scaled; and
performing prediction for the coding unit according to the motion information of the one of the sub-blocks; and
in response to the size of the coding unit being smaller than 8×8, skipping the processing.
2. An encoder comprising:
a memory storing computer executable instructions; and
a processor configured to execute the instructions to:
in response to a size of a coding unit being not smaller than 8×8, perform processing including:
dividing the coding unit into several sub-blocks each having a fixed size of 8×8;
obtaining M candidate motion vectors, M being an integer larger than 1, and the M candidate motion vectors including a motion vector of a left neighboring block of the coding unit;
scanning N candidate motion vectors of the M candidate motion vectors, N being an integer smaller than M, and:
in response to a reference frame pointed to by one candidate motion vector of the N candidate motion vectors being same as a co-located reference image of the coding unit, determining the one motion vector as a reference motion vector of the coding unit; and
in response to none of the N candidate motion vectors pointing to a reference frame same as the co-located reference image of the coding unit, determining a default value (0, 0) as the reference motion vector of the coding unit;
determining a related reference block of one of the sub-blocks of the coding unit in the co-located reference image of the coding unit according to the reference motion vector of the coding unit;
in response to a motion vector of the related reference block of the one of the sub-blocks pointing to a short-term reference image:
determining a scaling factor of the motion vector of the related reference block of the one of the sub-blocks according to:
a temporal distance between a reference image pointed to by the motion vector of the related reference block of the one of the sub-blocks and the co-located reference image of the coding unit, and
a temporal distance between the co-located reference image of the coding unit and an image containing the coding unit;
scaling the motion vector of the related reference block of the one of the sub-blocks using the scaling factor; and
determining motion information of the one of the sub-blocks according to the motion vector after being scaled;
in response to the motion vector of the related reference block of the one of the sub-blocks pointing to a long-term reference image:
setting the scaling factor of the motion vector of the related reference block of the one of the sub-blocks to 1;
scaling the motion vector of the related reference block of the one of the sub-blocks using the scaling factor; and
determining the motion information of the one of the sub-blocks according to the motion vector after being scaled; and
performing prediction for the coding unit according to the motion information of the one of the sub-blocks; and
in response to the size of the coding unit being smaller than 8×8, skip the processing.
3. A decoder comprising:
a memory storing computer executable instructions; and
a processor configured to execute the instructions to:
in response to a size of a coding unit being not smaller than 8×8, perform processing including:
dividing the coding unit into several sub-blocks each having a fixed size of 8×8;
obtaining M candidate motion vectors, M being an integer larger than 1, and the M candidate motion vectors including a motion vector of a left neighboring block of the coding unit;
scanning N candidate motion vectors of the M candidate motion vectors, N being an integer smaller than M, and:
in response to a reference frame pointed to by one candidate motion vector of the N candidate motion vectors being same as a co-located reference image of the coding unit, determining the one motion vector as a reference motion vector of the coding unit; and
in response to none of the N candidate motion vectors pointing to a reference frame same as the co-located reference image of the coding unit, determining a default value (0, 0) as the reference motion vector of the coding unit;
determining a related reference block of one of the sub-blocks of the coding unit in the co-located reference image of the coding unit according to the reference motion vector of the coding unit;
in response to a motion vector of the related reference block of the one of the sub-blocks pointing to a short-term reference image:
determining a scaling factor of the motion vector of the related reference block of the one of the sub-blocks according to:
a temporal distance between a reference image pointed to by the motion vector of the related reference block of the one of the sub-blocks and the co-located reference image of the coding unit, and
a temporal distance between the co-located reference image of the coding unit and an image containing the coding unit;
scaling the motion vector of the related reference block of the one of the sub-blocks using the scaling factor; and
determining motion information of the one of the sub-blocks according to the motion vector after being scaled;
in response to the motion vector of the related reference block of the one of the sub-blocks pointing to a long-term reference image:
setting the scaling factor of the motion vector of the related reference block of the one of the sub-blocks to 1;
scaling the motion vector of the related reference block of the one of the sub-blocks using the scaling factor; and
determining the motion information of the one of the sub-blocks according to the motion vector after being scaled; and
performing prediction for the coding unit according to the motion information of the one of the sub-blocks; and
in response to the size of the coding unit being smaller than 8×8, skip the processing.