Method and apparatus for video coding
Aspects of the disclosure provide methods and apparatuses for video encoding/decoding. In some examples, an apparatus for video decoding includes receiving circuitry and processing circuitry. For example, the processing circuitry decodes prediction information of a current block in a current picture from a coded video bitstream. The prediction information is indicative of an inter prediction mode with a potential usage of a refinement technique based on a first reference picture and a second reference picture. Then, the processing circuitry determines whether a first equal weighting condition of chroma components from the first reference picture and the second reference picture is satisfied. In response to a failure to satisfy the first equal weighting condition of the chroma components from the first reference picture and the second reference picture, the processing circuitry disables the refinement technique in a reconstruction of a sample in the current block.
1. A method for video decoding in a decoder, comprising:
decoding, by a processor, prediction information of a current block in a current picture from a coded video bitstream, the prediction information being indicative of an inter prediction mode with a potential usage of a refinement technique based on a first reference picture and a second reference picture;
determining, by the processor, whether a first equal weighting condition of chroma components from the first reference picture and the second reference picture is satisfied; and
disabling, by the processor, the refinement technique in a reconstruction of a sample in the current block in response to a failure to satisfy the first equal weighting condition of the chroma components from the first reference picture and the second reference picture.
2. The method of claim 1 , further comprising:
disabling, by the processor, the refinement technique in a reconstruction of a luma sample in the current block in response to the failure to satisfy the first equal weighting condition of the chroma components from the first reference picture and the second reference picture.
3. The method of claim 2 , further comprising:
determining, by the processor, whether a second equal weighting condition of luma components from the first reference picture and the second reference picture is satisfied; and
disabling, by the processor, the refinement technique in the reconstruction of the luma sample in the current block in response to a failure to satisfy at least one of the first equal weighting condition of the chroma components and the second equal weighting condition of the luma components.
4. The method of claim 1 , further comprising:
disabling, by the processor, the refinement technique in a reconstruction of a chroma sample in the current block in response to the failure to satisfy the first equal weighting condition of the chroma components from the first reference picture and the second reference picture.
5. The method of claim 1 , wherein the refinement technique includes at least one of bi-directional optical flow (BDOF) and decoder-side-motion vector refinement (DMVR).
6. The method of claim 1 , wherein one of the first reference picture and the second reference picture has a larger picture order count than the current picture and the other of the first reference picture and the second reference picture has a smaller picture order count than the current picture.
7. The method of claim 1 , further comprising:
determining, by the processor, the failure to satisfy the equal weighting condition of the chroma components from the first reference picture and the second reference picture based on at least one of a first flag for chroma weight of the first reference picture and a second flag for chroma weight of the second reference picture not being equal to zero.
8. An apparatus for video decoding, comprising:
processing circuitry configured to:
decode prediction information of a current block in a current picture from a coded video bitstream, the prediction information being indicative of an inter prediction mode with a potential usage of a refinement technique based on a first reference picture and a second reference picture;
determine whether a first equal weighting condition of chroma components from the first reference picture and the second reference picture is satisfied; and
disable the refinement technique in a reconstruction of a sample in the current block in response to a failure to satisfy the first equal weighting condition of the chroma components from the first reference picture and the second reference picture.
9. The apparatus of claim 8 , wherein the processing circuitry is configured to:
disable the refinement technique in a reconstruction of a luma sample in the current block in response to the failure to satisfy the first equal weighting condition of the chroma components from the first reference picture and the second reference picture.
10. The apparatus of claim 9 , wherein the processing circuitry is configured to:
determine whether a second equal weighting condition of luma components from the first reference picture and the second reference picture is satisfied; and
disable the refinement technique in the reconstruction of the luma sample in the current block in response to a failure to satisfy at least one of the first equal weighting condition of the chroma components and the second equal weighting condition of the luma components.
11. The apparatus of claim 8 , wherein the processing circuitry is configured to:
disable the refinement technique in a reconstruction of a chroma sample in the current block in response to the failure to satisfy the first equal weighting condition of the chroma components from the first reference picture and the second reference picture.
12. The apparatus of claim 8 , wherein the refinement technique includes at least one of bi-directional optical flow (BDOF) and decoder-side-motion vector refinement (DMVR).
13. The apparatus of claim 8 , wherein one of the first reference picture and the second reference picture has a larger picture order count than the current picture and the other of the first reference picture and the second reference picture has a smaller picture order count than the current picture.
14. The apparatus of claim 8 , wherein the processing circuitry is configured to:
determine the failure to satisfy the equal weighting condition of the chroma components from the first reference picture and the second reference picture based on at least one of a first flag for chroma weight of the first reference picture and a second flag for chroma weight of the second reference picture not being equal to zero.
15. A non-transitory computer-readable medium storing instructions which when executed by a computer for video decoding cause the computer to perform:
decoding prediction information of a current block in a current picture from a coded video bitstream, the prediction information being indicative of an inter prediction mode with a potential usage of a refinement technique based on a first reference picture and a second reference picture;
determining whether a first equal weighting condition of chroma components from the first reference picture and the second reference picture is satisfied; and
disabling the refinement technique in a reconstruction of a sample in the current block in response to a failure to satisfy the first equal weighting condition of the chroma components from the first reference picture and the second reference picture.
16. The non-transitory computer-readable medium of claim 15 , wherein the instructions cause the computer to further perform:
disabling the refinement technique in a reconstruction of a luma sample in the current block in response to the failure to satisfy the first equal weighting condition of the chroma components from the first reference picture and the second reference picture.
17. The non-transitory computer-readable medium of claim 16 , further comprising:
determining whether a second equal weighting condition of luma components from the first reference picture and the second reference picture is satisfied; and
disabling the refinement technique in the reconstruction of the luma sample in the current block in response to a failure to satisfy at least one of the first equal weighting condition of the chroma components and the second equal weighting condition of the luma components.
18. The non-transitory computer-readable medium of claim 15 , wherein the instructions cause the computer to further perform:
disabling the refinement technique in a reconstruction of a chroma sample in the current block in response to the failure to satisfy the first equal weighting condition of the chroma components from the first reference picture and the second reference picture.
19. The non-transitory computer-readable medium of claim 15 , wherein the refinement technique includes at least one of bi-directional optical flow (BDOF) and decoder-side-motion vector refinement (DMVR).
20. The non-transitory computer-readable medium of claim 15 , wherein the instructions cause the computer to further perform:
determining the failure to satisfy the equal weighting condition of the chroma components from the first reference picture and the second reference picture when at least one of a first flag for chroma weight of the first reference picture and a second flag for chroma weight of the second reference picture is not equal to zero.