Method and device for obtaining motion vector of video image
A video processing method includes obtaining motion information of a neighboring block of a current image block, dividing the current image block into a plurality of sub-blocks in response to the neighboring block satisfying a preset condition, determining, in a time-domain reference image of the current image block, related blocks of the plurality of sub-blocks according to a motion vector of the neighboring block, and performing prediction on the current image block according to motion vectors of the related blocks.
1. A video processing method comprising:
obtaining motion information of a left neighboring block of a current image block, the current image block being divided into one or more sub-blocks each having a size of 8×8 pixels; and
in response to the left neighboring block satisfying a preset condition:
determining, in a collocated frame of the current image block, a related block of one sub-block of the one or more sub-blocks using a motion vector of the left neighboring block as a motion offset, the preset condition including that a reference image of the left neighboring block is same as the collocated frame of the current image block; and
determining a motion vector of the one sub-block according to a motion vector of the related block of the one sub-block, to perform encoding/decoding on the one sub-block of the current image block;
wherein determining the motion vector of the one sub-block according to the motion vector of the related block of the one sub-block, to perform encoding/decoding on the one sub-block of the current image block includes:
in response to reference images of the related block and the one sub-block not being specific reference images, scaling the motion vector of the related block of the one sub-block to obtain the motion vector of the one sub-block;
wherein scaling the motion vector of the related block of the one sub-block to obtain the motion vector of the one sub-block includes:
determining a scaling factor of the motion vector of the related block of the one sub-block according to:
a temporal distance between a reference image pointed to by the motion vector of the related block of the one sub-block and an image where the related block is located, and
a temporal distance between a reference image of the one sub-block and a current image containing the one sub-block;
scaling the motion vector of the related block of the one sub-block according to the scaling factor to obtain a scaled motion vector; and
determining the motion vector of the one sub-block according to the scaled motion vector.
2. The method of claim 1 , further comprising:
in response to the left neighboring block not satisfying the preset condition, encoding the one sub-block using a default block as a reference block of the one sub-block.
3. The method of claim 2 , wherein the default block is an image block pointed to by a motion vector (0, 0).
4. The method of claim 3 , wherein the default block is an image block pointed to by the motion vector (0, 0) in the collocated frame of the current image block.
5. The method of claim 1 , further comprising:
outputting a bitstream obtained by encoding the one sub-block of the current image block.
6. The method of claim 1 , further comprising:
in response to the current image block having a size larger than or equal to 8×8 pixels, dividing the current image block into the one or more sub-blocks each having the size of 8×8 pixels, and executing the process of determining the motion vector of the one sub-block according to the motion vector of the related block of the one sub-block.
7. The method of claim 1 , wherein determining the motion vector of the one sub-block according to the motion vector of the related block of the one sub-block, to perform encoding/decoding on the one sub-block of the current image block includes:
in response to reference images of the related block and the one sub-block being specific reference images, skipping a process of scaling the motion vector of the related block of the one sub-block.
8. A video processing device comprising:
a processor; and
a memory storing instructions that, when executed by the processor, cause the processor to:
obtain motion information of a left neighboring block of a current image block, the current image block being divided into one or more sub-blocks each having a size of 8×8 pixels; and
in response to the left neighboring block satisfying a preset condition:
determine, in a collocated frame of the current image block, a related block of one sub-block of the one or more sub-blocks using a motion vector of the left neighboring block as a motion offset, the preset condition including that a reference image of the left neighboring block is same as the collocated frame of the current image block; and
determine a motion vector of the one sub-block according to a motion vector of the related block of the one sub-block, to perform encoding/decoding on the one sub-block of the current image block;
wherein determining the motion vector of the one sub-block according to the motion vector of the related block of the one sub-block, to perform encoding/decoding on the one sub-block of the current image block includes:
in response to reference images of the related block and the one sub-block not being specific reference images, scale the motion vector of the related block of the one sub-block to obtain the motion vector of the one sub-block;
wherein scaling the motion vector of the related block of the one sub-block to obtain the motion vector of the one sub-block includes:
determining a scaling factor of the motion vector of the related block of the one sub-block according to:
a temporal distance between a reference image pointed to by the motion vector of the related block of the one sub-block and an image where the related block is located, and
a temporal distance between a reference image of the one sub-block and a current image containing the one sub-block;
scaling the motion vector of the related block of the one sub-block according to the scaling factor to obtain a scaled motion vector; and
determining the motion vector of the one sub-block according to the scaled motion vector.
9. The device of claim 8 , wherein the instructions further cause the processor to:
in response to the left neighboring block not satisfying the preset condition, encode the one sub-block using a default block as a reference block of the one sub-block.
10. The device of claim 9 , wherein the default block is an image block pointed to by a motion vector (0, 0).
11. The device of claim 10 , wherein the default block is an image block pointed to by the motion vector (0, 0) in the collocated frame of the current image block.
12. The device of claim 8 , wherein the instructions further cause the processor to:
output a bitstream obtained by encoding the one sub-block of the current image block.
13. The device of claim 8 , wherein the instructions further cause the processor to:
in response to the current image block having a size larger than or equal to 8×8 pixels, divide the current image block into the one or more sub-blocks each having the size of 8×8 pixels, and execute the process of determining the motion vector of the one sub-block according to the motion vector of the related block of the one sub-block.
14. The device of claim 8 , wherein the instructions further cause the processor to:
in response to reference images of the related block and the one sub-block being specific reference images, skip a process of scaling the motion vector of the related block of the one sub-block.
15. A non-transitory computer-readable storage medium storing bitstream obtained by an encoding method including:
obtaining motion information of a left neighboring block of a current image block, the current image block being divided into one or more sub-blocks each having a size of 8×8 pixels; and
in response to the left neighboring block satisfying a preset condition:
determining, in a collocated frame of the current image block, a related block of one sub-block of the one or more sub-blocks using a motion vector of the left neighboring block as a motion offset, the preset condition including that a reference image of the left neighboring block is same as the collocated frame of the current image block; and
determining a motion vector of the one sub-block according to a motion vector of the related block of the one sub-block, to perform encoding on the one sub-block of the current image block;
wherein determining the motion vector of the one sub-block according to the motion vector of the related block of the one sub-block, to perform encoding on the one sub-block of the current image block includes:
in response to reference images of the related block and the one sub-block not being specific reference images, scaling the motion vector of the related block of the one sub-block to obtain the motion vector of the one sub-block;
wherein scaling the motion vector of the related block of the one sub-block to obtain the motion vector of the one sub-block includes:
determining a scaling factor of the motion vector of the related block of the one sub-block according to:
a temporal distance between a reference image pointed to by the motion vector of the related block of the one sub-block and an image where the related block is located, and
a temporal distance between a reference image of the one sub-block and a current image containing the one sub-block;
scaling the motion vector of the related block of the one sub-block according to the scaling factor to obtain a scaled motion vector; and
determining the motion vector of the one sub-block according to the scaled motion vector.
16. The storage medium of claim 15 , wherein the method further includes:
in response to the left neighboring block not satisfying the preset condition, encoding the one sub-block using a default block as a reference block of the one sub-block.