Merge Candidate Availability in Video Coding

The patent segments the merge candidate selection process by introducing separate handling for different partition types. It divides the candidate block availability determination into distinct cases: QT partitions follow traditional MER rules, while BT and TT partitions use modified availability checking that accounts for their non-square geometry. This segmentation allows each partition type to be optimized independently, resolving the conflict between flexibility and performance.

The patent applies local quality by making the merge candidate availability rules location-dependent and pattern-dependent. Different MER condition checks are applied based on the specific partition pattern (QT, BT, or TT) and the relative positions of candidate blocks. This localized approach ensures that each region is evaluated with appropriate criteria, maintaining coding performance across diverse partition patterns.

The patent segments the parallel processing workflow by introducing independent availability determination for different partition types. QT partitions can be processed with traditional MER rules, while BT and TT partitions use specialized availability checks that don't rely on square-grid assumptions. This segmentation enables parallel processing units to handle different partition types independently without waiting for MER condition resolution, improving overall parallel efficiency.

The patent changes the parameters used for MER condition evaluation when dealing with BT and TT partitions. Instead of using fixed square-grid based MER rules, the patent modifies the availability checking parameters to account for non-square block geometries. This parameter adaptation allows parallel processing to proceed efficiently with irregular partition patterns while maintaining coding accuracy.

The patent applies local quality by implementing location-aware availability checking for merge candidates. The determination of whether a candidate block is available depends on its specific position relative to the current block and the partition pattern type. This localized precision ensures accurate merge estimation for each candidate without requiring complex global re-evaluation, balancing simplicity and accuracy.

The patent changes the evaluation parameters for merge candidate availability based on partition pattern characteristics. For BT and TT partitions, the patent modifies the spatial relationship checks and availability criteria to match the non-square geometry. These parameter adjustments maintain processing simplicity while significantly improving merge estimation accuracy for irregular partitions compared to traditional square-grid assumptions.