Implicit Interpolation Filter Selection via Prediction Unit Size Mapping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-efficiency video coding (HEVC) requires explicit signaling of adaptive interpolation filters, which increases bit rate and overhead due to the need to communicate filter coefficients for each prediction unit, especially in temporally predictive pictures.
Innovation Solution
Implementing an implicit signaling method that determines the interpolation filter based on a mapping between filter sets and prediction unit sizes or prediction indices, eliminating the need for explicit communication between encoder and decoder.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If explicit signaling of adaptive interpolation filters is used, then coding efficiency is improved, but bit rate overhead increases
Solution Approach 1:
The patent extracts the filter selection information from explicit signaling and embeds it implicitly within existing video coding parameters. Specifically, the interpolation filter type is determined by the prediction unit size or prediction index, which are already being transmitted in the bitstream, thereby eliminating the need for separate filter signaling without sacrificing coding efficiency
Solution Approach 2:
The patent introduces an intermediary mapping relationship between existing coding parameters (prediction unit size, prediction index) and interpolation filter types. This mapping acts as a mediator that allows the decoder to infer the correct filter without direct signaling, resolving the contradiction between efficiency and overhead
2Productivity
If adaptive interpolation filters are used for each PU, then compression performance is improved, but device complexity increases
Solution Approach 1:
The patent makes the prediction unit size and prediction index serve dual functions: both defining the prediction block structure and implicitly indicating the interpolation filter type. This multi-functionality reduces the need for separate filter configuration mechanisms, thereby reducing encoder and decoder complexity while maintaining adaptive filter benefits
Solution Approach 2:
The patent changes the parameter space by using discrete, already-present parameters (PU size categories, prediction indices) to indirectly select filter types rather than requiring continuous or separate filter parameter signaling. This approach maintains adaptability while simplifying the encoding/decoding process
Data Source
AI summary
In one embodiment, a method for encoding or decoding video content is provided. The method includes determining a set of interpolation filters for use in interpolating sub-pel pixel values and a mapping between interpolation filters in the set of interpolation filters and different sizes of prediction units (PUs) of video content. A PU of video content is received and a size of the received PU is determined The method determines an interpolation filter in the set of interpolation filters based on a mapping between the interpolation filter and the size of the received PU to interpolate a sub-pel pixel value for use in a temporal prediction process for the PU.