Entropy Coding Mode Switching for Decoder Complexity-Efficiency Balance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current media codecs face challenges in achieving a balance between coding complexity and efficiency, particularly in handheld devices with limited energy resources, where simpler codecs are advantageous but may compromise on efficiency, and more complex codecs provide better efficiency but at the cost of increased complexity and compatibility requirements.
Innovation Solution
A decoder and encoder system that switches between low-complexity and high-efficiency modes by selecting appropriate entropy decoding/encoding schemes based on probability estimates, allowing for adaptive processing to optimize complexity and efficiency based on data stream requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If arithmetic coding schemes are used for entropy coding, then coding efficiency is improved, but device complexity increases
Solution Approach 1:
The patent implements dynamic mode switching between CABAC (arithmetic coding) and CAVLC (variable length coding) based on profile/level parameters and data characteristics. The entropy decoding engine can adaptively select the appropriate coding scheme during decoding, allowing the system to optimize between efficiency and complexity based on actual requirements rather than being fixed to one approach.
2Productivity
If main profile conform decoders are used to support arithmetic coding, then coding efficiency is improved, but energy consumption increases due to higher complexity
Solution Approach 1:
The patent enables dynamic selection between CABAC and CAVLC modes based on profile/level parameters and data characteristics. The entropy decoding engine can adaptively switch between arithmetic coding and variable length coding during decoding, allowing handheld devices to reduce energy consumption by selecting CAVLC when appropriate while still achieving good compression efficiency when CABAC is selected.
3Device complexity
If low-complexity variable length coding schemes are used, then device complexity is reduced, but coding efficiency deteriorates
Solution Approach 1:
The patent creates a universal entropy decoding engine that can perform both CABAC (arithmetic decoding) and CAVLC (variable length decoding) operations. This multi-functional design allows the same hardware or software module to efficiently execute either coding scheme based on the selected mode, eliminating the need for separate dedicated decoders for each approach and enabling flexible adaptation to different efficiency requirements.
Data Source
AI summary
A decoder for decoding a data stream into which media data is coded has a mode switch configured to activate a low-complexity mode or a high-efficiency mode depending on the data stream, an entropy decoding engine configured to retrieve each symbol of a sequence of symbols by entropy decoding using a selected one of a plurality of entropy decoding schemes, a desymbolizer configured to desymbolize the sequence of symbols to obtain a sequence of syntax elements, a reconstructor configured to reconstruct the media data based on the sequence of syntax elements, selection depending on the activated low-complexity mode or the high-efficiency mode. In another aspect, a desymbolizer is configured to perform desymbolization such that the control parameter varies in accordance with the data stream at a first rate in case of the high-efficiency mode being activated and the control parameter is constant irrespective of the data stream or changes depending on the data stream, but at a second lower rate in case of the low-complexity mode being activated.