Intra Mode Derivation from Inter-Coded Blocks for MPM Lists
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Solution Overview
Problem
Existing video encoding and decoding technologies face inefficiencies in constructing the Most Probable Mode (MPM) list, particularly when neighboring blocks are inter-coded, leading to deficiencies in intra mode derivation and increased signaling overhead.
Innovation Solution
The method involves deriving intra coding modes from inter-coded neighboring blocks and conditionally adding them to the MPM list, using techniques such as Decoder-side Intra Mode Derivation (DIMD), Template-based Intra Mode Derivation (TIMD), and Combined Inter-intra Prediction (CIIP) to enhance the MPM list construction, especially for non-square blocks and blocks with inter-coded neighbors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If intra mode derivation is performed from inter-coded neighboring blocks, then coding efficiency is improved, but device complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-deriving intra coding modes from inter-coded neighboring blocks and storing them in the MPM list before actual encoding/decoding operations. This allows the decoder to have access to accurate intra mode information in advance, improving coding efficiency without requiring complex real-time derivation during the main decoding process.
Solution Approach 2:
The patent introduces an intermediary mechanism by using the MPM list as a buffer between inter-coded neighboring blocks and the final intra mode selection. The derived intra modes are stored in this intermediary structure, allowing efficient retrieval and use during encoding/decoding while avoiding direct complex computations at runtime.
2Measurement precision
If the MPM list is constructed with more intra modes, then intra mode derivation accuracy is improved, but signaling overhead increases
Solution Approach 1:
The patent extracts only the necessary intra mode information from inter-coded neighboring blocks and stores it in the MPM list. By selectively taking out and storing only the relevant derived intra modes rather than all possible modes, the system achieves high derivation accuracy while minimizing the signaling overhead required to transmit mode information.
3Productivity
If intra modes are derived from inter-coded blocks, then coding performance is enhanced, but processing time increases
Solution Approach 1:
The patent performs intra mode derivation as a preliminary action during the encoding phase and stores the results in the MPM list. This allows the decoder to simply retrieve pre-computed modes without performing time-consuming derivation operations during decoding, thereby enhancing coding performance while minimizing processing time at the critical decoding stage.
Data Source
AI summary
Intra prediction modes are determined for entry in most probable mode lists for encoding in video encoders and decoding in video decoders. In at least one embodiment, coding modes are derived to determine reference samples to use from inter coded neighboring blocks. In one embodiment, up to five neighboring blocks are used. The reference samples are used in an intra prediction mode to determined prediction samples. The reference samples are used for prediction in encoding or decoding. In at least one embodiment, one of several motion models can be used to extract the intra motion mode. The intra motion modes are used to fill a most probable mode list. The motion model, intra mode, or reference frame can be signaled from an encoder to a decoder.