Constraints for usage of updated motion information

An apparatus for processing video data comprising a processor and a non-transitory memory with instructions thereon, wherein the instructions upon execution by the processor, cause the processor to:

• determine, for a conversion between a current block of a video and a bitstream of the video, motion information associated with the current block;
• refine, based on a first coding tool, the motion information to acquire first motion information that is refined motion vector, wherein the first coding tool is a bi-directional optical flow coding tool and is used to acquire a first offset for refining the motion information;
• generate, based on the first motion information from the current block, a first prediction for the current block;
• updating, based on a second coding tool, the first prediction to acquire a second prediction, wherein the second coding tool is a bi-directional optical flow coding tool and is used to acquire second offset for updating the first prediction;
• and
• perform, based on the second prediction, the conversion.

A non-transitory computer-readable storage medium storing instructions that cause a processor to:

• determine, for a conversion between a current block of a video and a bitstream of the video, motion information associated with the current block;
• refine, based on a first coding tool, the motion information to acquire first motion information that is refined motion vector, wherein the first coding tool is a bi-directional optical flow coding tool and is used to acquire a first offset for refining the motion information;
• generate, based on the first motion information from the current block, a first prediction for the current block;
• update, based on a second coding tool, the first prediction to acquire a second prediction, wherein the second coding tool is a bi-directional optical flow coding tool and is used to acquire second offset for updating the first prediction;
• and
• perform, based on the second prediction, the conversion.

A non-transitory computer-readable recording medium storing a bitstream of a video which is generated by a method performed by a video processing apparatus, wherein the method comprises:

• determining, for a current block of a video, motion information associated with the current block;
• refining, based on a first coding tool, the motion information to acquire first motion information that is refined motion vector, wherein the first coding tool is a bi-directional optical flow coding tool and is used to acquire a first offset for refining the motion information;
• generating, based on the first motion information from the current block, a first prediction for the current block;
• updating, based on a second coding tool, the first prediction to acquire a second prediction, wherein the second coding tool is a bi-directional optical flow coding tool and is used to acquire second offset for updating the first prediction;
• and
• generating, based on the second prediction, the bitstream.