Variable Length Coding Apparatus Parameter Extraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional image coding apparatuses for H.264/AVC face increased arithmetic processing and expanded LSI circuit size due to the need for decoding and extracting parameter information from coded header information before performing arithmetic coding.
Innovation Solution
An image coding apparatus that extracts parameter information from coding conditions not coded, allowing it to perform variable length coding without decoding the header information, thereby reducing processing and LSI circuit size by synthesizing the parameter information into the intermediate stream and using a unique start code for detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If header information is decoded and parameter information is extracted before arithmetic coding, then variable length coding can be performed correctly, but arithmetic processing increases and LSI circuit size expands
Solution Approach 1:
The patent extracts only the necessary parameter information (pic_width_in_mb, pic_height_in_mb, slice_width, slice_height, slice_type) from the header before coding, and passes these extracted parameters directly to the arithmetic coding unit. This eliminates the need for the arithmetic coding unit to decode and extract parameters itself, thereby reducing circuit complexity while maintaining coding accuracy.
Solution Approach 2:
The patent performs parameter extraction in advance during the intermediate code generation phase, before arithmetic coding begins. The extracted parameters are stored and made available to the arithmetic coding unit without requiring it to perform decoding operations. This preliminary action reduces the computational burden and circuit complexity of the arithmetic coding unit.
2Loss of information
If header information is decoded before variable length coding, then parameter information can be obtained, but processing time and arithmetic operations increase
Solution Approach 1:
The patent performs parameter extraction during the intermediate code generation phase, which occurs before arithmetic coding. By extracting parameters in advance and making them available to the arithmetic coding unit, the system avoids time-consuming decoding operations during the critical arithmetic coding phase, thereby reducing overall processing time.
Solution Approach 2:
The patent separates the parameter extraction function from the arithmetic coding function. The intermediate code generating unit extracts parameters, while the arithmetic coding unit uses these pre-extracted parameters directly. This segmentation allows parameter extraction to occur in parallel or beforehand, reducing the critical path time for arithmetic coding.
Data Source
AI summary
An image coding apparatus reduces arithmetic processing and includes an intermediate stream generating unit generating an intermediate stream, by generating an intermediate code from image data, coding header information among coding conditions for image coding, and synthesizing the generated intermediate code and the coded header information. The image coding apparatus also includes a coded stream generating unit outputting a coded stream, by performing variable length coding on the intermediate code included in the intermediate stream to generate coded image data, and synthesizing the generated coded image data and the header information, and includes a parameter information extracting unit extracting, from among the coding conditions, parameter information required for performing variable length coding on the intermediate code. The coded stream generating unit generates the coded image data by performing the variable length coding on the intermediate code using the parameter information extracted by the parameter information extracting unit.