Video Prediction With Adaptive Motion Vector List Length

The patent introduces a parameter `sps_sbtmvp_enabled_flag` that can be configured to enable or disable advanced temporal motion vector prediction. By changing this parameter's value, the system can adapt the candidate motion vector list length determination between two modes: using the full list when the flag is enabled, or using a reduced list when disabled. This parameter change approach resolves the contradiction by allowing flexible adjustment of complexity based on prediction accuracy requirements.

The patent implements a dynamic determination method where the candidate motion vector list length is not fixed but can be adjusted based on the `sps_sbtmvp_enabled_flag` parameter. The system dynamically selects between different list lengths (full list or reduced list) depending on the prediction mode and configuration, making the complexity adaptive rather than static.

The patent performs preliminary action by parsing the `sps_sbtmvp_enabled_flag` parameter before determining the candidate motion vector list length. This flag is extracted from the bitstream in advance, allowing the system to pre-determine which determination method to use (full list or reduced list) based on the predicted picture type and the flag's value, thereby simplifying the subsequent parsing and processing steps.

The patent segments the bitstream parsing process into distinct steps: first parsing the `sps_sbtmvp_enabled_flag`, then using this information to determine the appropriate candidate motion vector list length. This segmentation separates the complexity of parsing the flag from the complexity of determining the list length, making the overall process more manageable and efficient.

The patent uses the `sps_sbtmvp_enabled_flag` parameter to change the candidate motion vector list length between different values. When the flag is enabled and the predicted picture type requires it, the system uses a longer list for improved accuracy. When the flag is disabled or the picture type doesn't require it, the system uses a shorter list to maintain efficiency. This parameter-driven change resolves the contradiction by making list length adaptive rather than fixed.

The patent applies partial action by using a reduced candidate motion vector list length in certain cases (when `sps_sbtmvp_enabled_flag` is disabled or when prediction accuracy isn't critical). Instead of always using the full list, the system selectively applies the full list only when necessary, thereby avoiding excessive computational complexity while maintaining sufficient prediction accuracy for most cases.