Video Block Coding with Iterative BDOF Refinement

The patent segments the BDOF process into multiple iterative rounds, where each round refines motion vectors and sample values independently. This segmentation allows progressive improvement of coding quality through successive refinements while maintaining manageable computational complexity for each individual round.

The patent applies preliminary BDOF processing rounds before final encoding to pre-refine motion vectors and sample values. This preliminary action improves the quality of subsequent encoding steps by providing better initial estimates, thereby enhancing overall coding quality without proportionally increasing final encoding complexity.

The patent applies a limited number of BDOF rounds (e.g., 2-3 rounds) rather than exhaustive processing. This partial action provides sufficient refinement to improve coding quality while avoiding the exponential complexity increase that would result from excessive rounds, achieving an optimal balance between quality improvement and computational burden.

The patent implements BDOF processing as periodic iterative rounds with fixed intervals. Each round processes motion vectors and sample values at regular computational stages, providing structured quality improvement while preventing uncontrolled complexity accumulation through predetermined processing cycles.