Video Signal Entropy Coding Using Inter-Layer Context Modeling
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Solution Overview
Problem
Scalable Video Coding (SVC) experiences significant reduction in image quality when bitrate is lowered, necessitating the use of auxiliary picture sequences with lower screen size and frame rate, and there is a need for improved entropy coding methods to enhance coding efficiency.
Innovation Solution
The method involves context modeling of coding information using Context Adaptive Binary Arithmetic Coding (CABAC) by determining initial probability coding values based on inter-layer relationships and flags such as base_mode_flag, residual_prediction_flag, and intra_base_flag, which utilize coding information from both the current and base layers to optimize probability coding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If bitrate is lowered to reduce data transmission requirements, then data compression is improved, but image quality is significantly reduced
Solution Approach 1:
The video stream is segmented into multiple layers (base layer and enhancement layers) with different quality levels. The base layer provides low-quality video at low bitrate, while enhancement layers add quality improvement. This allows flexible quality-bitrate tradeoff by selectively decoding layers based on available bandwidth and quality requirements.
Solution Approach 2:
Different regions of the video are coded with different precision and quality characteristics. The context modeling technique applies different probability models to different coding information types and positions, optimizing compression efficiency locally without requiring uniform high quality across the entire video stream.
2Manufacturing precision
If auxiliary picture sequence with lower screen size and frame rate is provided to maintain quality at low bitrate, then image quality is maintained, but device complexity increases
Solution Approach 1:
The context modeling technique is designed to work universally across different video coding scenarios and layer configurations. The same CABAC framework with adaptive probability modeling can handle various flag types (base_mode_flag, residual_prediction_flag, intra Base flag) and coding information without requiring separate specialized coding mechanisms for each case.
Solution Approach 2:
The system dynamically adjusts probability coding parameters based on coding information flags and context models. By adapting the probability models according to the specific coding situation (intra mode, inter mode, residual prediction, etc.), the system optimizes compression efficiency without adding significant complexity to the overall coding structure.
3Productivity
If context modeling based on inter-layer relationships is applied to optimize probability coding, then data compression rate is increased, but device complexity increases
Solution Approach 1:
The context modeling technique copies and adapts probability models from base layer coding information to enhance layer coding. By using the base layer's coding statistics and patterns to initialize or refine the enhancement layer's probability models, the system achieves better compression without requiring completely separate modeling for each layer, thus reducing overall complexity.
Solution Approach 2:
The context modeling process uses feedback from coding information flags and decoded data to continuously refine probability models. The decoded coding information is fed back into the context models to update probability estimates, creating an adaptive system that improves compression efficiency through iterative refinement rather than complex one-time calculations.
Data Source
AI summary
A method and an apparatus of decoding a video signal are provided. The present invention includes the steps of parsing first coding information indicating whether a residual data of an image block in the enhanced layer is predicted from a corresponding block in the base layer, from the bitstream of the enhanced layer, and decoding the video signal based on the first coding information. And, the step of parsing includes the step of performing modeling of the first coding information based on second coding information indicating whether prediction information of the corresponding block in the base layer is used to decode the image block in the enhanced layer. Accordingly, the present invention raises efficiency of video signal processing by enabling a decoder to derive information on a prediction mode of a current block in a decoder instead of transferring the information to the decoder.