Video coding method and apparatus

1. A method for obtaining a motion vector, comprising:

determining a reference block of a to-be-processed block, wherein the reference block and the to-be-processed block have a preset temporal or spatial correlation, the reference block is obtained based on a prediction block of the reference block determined by a refined initial motion vector, the refined initial motion vector is obtained based on an initial motion vector of the reference block and one or more preset motion vector offsets, and the initial motion vector of the reference block is obtained based on a predicted motion vector of the reference block; and

using the initial motion vector of the reference block as a predicted motion vector of the to-be-processed block.

2. The method according to claim 1 , further comprising:

using the predicted motion vector of the reference block as the initial motion vector of the reference block to obtain the initial motion vector; or

adding the predicted motion vector of the reference block and a motion vector difference of the reference block to obtain the initial motion vector.

3. The method according to claim 1 , further comprising:

using the predicted motion vector of the to-be-processed block as an initial motion vector of the to-be-processed block.

4. The method according to claim 1 , further comprising:

adding the predicted motion vector of the to-be-processed block and a motion vector difference of the to-be-processed block to obtain an initial motion vector of the to-be-processed block.

5. The method according to claim 4 , wherein the motion vector difference of the to-be-processed block is obtained by parsing first identification information in a bitstream.

6. The method according to claim 1 , wherein determining the reference block of the to-be-processed block comprises:

parsing a bitstream to obtain identification information; and

determining the reference block of the to-be-processed block based on the identification information.

7. The method according to claim 1 , wherein the reference block of the to-be-processed block and the to-be-processed block are processed in parallel.

8. The method according to claim 1 , wherein the to-be-processed block is processed based on the predicted motion vector obtained by performing an advanced motion vector prediction (AMVP) operation or a merge operation.

9. An apparatus for obtaining a motion vector, comprising:

a memory,

a processor coupled to the memory that stores instructions, which when executed by the processor, cause the processor to:

determine a reference block of a to-be-processed block, wherein the reference block and the to-be-processed block have a preset temporal or spatial correlation, the reference block is obtained based on a prediction block of the reference block determined by a refined initial motion vector, the refined initial motion vector is obtained based on an initial motion vector of the reference block and one or more preset motion vector offsets, and the initial motion vector of the reference block is obtained based on a predicted motion vector of the reference block; and

use the initial motion vector of the reference block as a predicted motion vector of the to-be-processed block.

10. The apparatus according to claim 9 , wherein the instructions, when executed by the processor, further cause the processor to:

use the predicted motion vector of the to-be-processed block as an initial motion vector of the to-be-processed block.

11. The apparatus according to claim 9 , wherein the instructions, when executed by the processor, further cause the processor to:

add the predicted motion vector of the to-be-processed block and a motion vector difference of the to-be-processed block to obtain an initial motion vector of the to-be-processed block.

12. The apparatus according to claim 11 , wherein the motion vector difference of the to-be-processed block is obtained by parsing first identification information in a bitstream.

13. The apparatus according to claim 9 , wherein to determine the reference block of the to-be-processed block, the instructions, when executed by the processor, further cause the processor to:

parse a bitstream to obtain identification information; and

determine the reference block of the to-be-processed block based on the identification information.

14. The apparatus according to claim 9 , wherein to determine the reference block of the to-be-processed block, the instructions, when executed by the processor, further cause the processor to:

select, from one or more candidate reference blocks of the to-be-processed block, a candidate reference block having a minimum rate-distortion cost as the reference block of the to-be-processed block.

15. The apparatus according to claim 9 , wherein the reference block of the to-be-processed block and the to-be-processed block are processed in parallel.

16. The apparatus according to claim 9 , wherein the to-be-processed block is processed based on the predicted motion vector obtained by performing an advanced motion vector prediction (AMVP) operation or a merge operation.

17. A method of decoding a picture, comprising:

determining a reference block of a to-be-processed block of the picture, wherein the reference block and the to-be-processed block have a preset temporal or spatial correlation, the reference block is obtained based on a prediction block of the reference block determined by a refined initial motion vector, the refined initial motion vector is obtained based on an initial motion vector of the to-be-processed block and one or more preset motion vector offsets, and the initial motion vector is obtained based on a predicted motion vector of the reference block;

using the initial motion vector as a predicted motion vector of the to-be-processed block;

obtaining a final motion vector of the to-be-processed block based on the predicted motion vector of the to to-be-processed block; and

decoding the to to-be-processed block based on the final motion vector.

18. The method according to claim 17 , further comprising:

using the predicted motion vector of the reference block as the initial motion vector of the reference block to obtain the initial motion vector; or

adding the predicted motion vector of the reference block and a motion vector difference of the reference block to obtain the initial motion vector.

19. The method according to claim 17 , further comprising:

using the predicted motion vector of the to-be-processed block as an initial motion vector of the to-be-processed block,

wherein obtaining the final motion vector of the to-be-processed block comprises refining the initial motion vector of the to-be-processed block to obtain the refined initial motion vector.

20. The method according to claim 17 , further comprising:

adding the predicted motion vector of the to-be-processed block and a motion vector difference of the to-be-processed block to obtain an initial motion vector of the to-be-processed block,

wherein obtaining the final motion vector of the to-be-processed block comprises refining the initial motion vector of the to-be-processed block to obtain the refined initial motion vector.