Method for entropy-decoding slice segments
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Solution Overview
Problem
Conventional video codecs face challenges in efficiently encoding and decoding high-resolution video content, particularly in managing context variables across slice segments during entropy encoding and decoding, leading to suboptimal compression ratios and data size reduction.
Innovation Solution
A video entropy decoding method that utilizes context information from nearby data to determine the attribute of a slice segment, allowing for the storage of context variables after entropy encoding/decoding of the last maximum coding unit (LCU) of each slice segment, and provides information indicating a subset offset to synchronize context variables efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If context variables are stored for all slice segments, then decoding reliability is improved, but device complexity and memory usage increase
Solution Approach 1:
The patent segments slice segments into two types: dependent slice segments that can share context variables with previous slice segments, and independent slice segments that require full context variable storage. This segmentation allows the system to reduce memory usage and device complexity while maintaining decoding reliability for independent segments and enabling efficient compression for dependent segments.
Solution Approach 2:
The patent introduces a parameter change by storing context variables only when needed (for independent slice segments) and reusing them for dependent slice segments. This dynamic approach to context variable management reduces the overall number of stored variables while maintaining decoding accuracy where required.
2Loss of substance
If context variables are reused across slice segments, then data size reduction is improved, but measurement precision of slice segment attributes worsens
Solution Approach 1:
The patent segments slice segments into dependent and independent types, allowing context variable reuse for dependent segments (reducing data size) while maintaining full context storage for independent segments (preserving measurement precision). The segmentation enables the system to identify when precision is needed versus when compression is acceptable.
Solution Approach 2:
Different quality levels of context variable storage are applied to different slice segments based on their type. Independent slice segments receive full precision treatment with complete context variable storage, while dependent slice segments use compressed representation by reusing context variables from previous segments, optimizing the balance between data size reduction and precision.
3Reliability
If context variables are initialized for each slice segment, then decoding reliability is improved, but productivity decreases due to increased processing overhead
Solution Approach 1:
The patent segments the initialization process by applying it only to independent slice segments while skipping it for dependent slice segments. This selective initialization maintains decoding reliability for independent segments (which require it) while improving productivity by avoiding redundant initialization operations in dependent segments.
Solution Approach 2:
Context variables are initialized in advance for independent slice segments before decoding begins, ensuring reliability is established where needed. For dependent slice segments, the preliminary action of initialization is omitted since the context will be inherited from previous segments, thereby improving processing efficiency and productivity.
Data Source
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AI summary
A video decoding method comprising obtaining, from a bitstream, information about a maximum size of a coding unit, obtaining, from the bitstream, first information indicating whether a dependent slice segment is permitted to be included in a picture, determining at least one maximum coding unit included in a first slice segment, based on a maximum coding unit size, which is determined by using the information about the maximum size, obtaining, from the bitstream, second information indicating whether a current maximum coding unit is at an end of the first slice segment or not. The method includes storing a context variable of the first slice segment if the first information indicates that a dependent slice segment is permitted to be included in the picture and the second information indicates that the current maximum coding unit is at the end of the first slice segment, obtaining sixth information, from the bitstream, which indicates whether a second slice segment is a dependent slice segment or not; and decoding the second slice segment by using the stored context variable when the sixth information indicates that the second slice segment is a dependent slice segment; wherein the second slice segment is located next to the first slice segment.