SoC Adaptive Bit Rate Control via Spatial Filtering and Quantization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional codecs adjust bit rates primarily through quantization parameters, which limits adaptive control over bit rates in video processing, affecting compression efficiency and quality.
Innovation Solution
A System on Chip (SoC) with a central processing unit (CPU) compares reference bit rates to adjust cutoff frequencies and bit rates of frames and macroblocks, using spatial filters and video codecs to dynamically control bit rates based on previous frame and macroblock rates, incorporating quantization step size adjustments and entropy coding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If quantization parameter is increased to decrease bit rate, then compression rate improves, but picture quality deteriorates
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the quantization parameter based on macroblock complexity classification. Different quantization parameters are assigned to different macroblock types (intra-prediction, inter-prediction, skip, etc.), allowing optimized bit rate control while maintaining picture quality. The CPU classifies macroblocks and selects appropriate quantization parameters from a table, achieving adaptive quantization that resolves the contradiction between bit rate reduction and quality maintenance.
2Device complexity
If conventional codec adjusts bit rate using only quantization parameter, then device complexity is reduced, but adaptability of bit rate control deteriorates
Solution Approach 1:
The patent implements dynamics by introducing a dynamic bit rate control mechanism that adapts to different macroblock types and coding modes. The system dynamically selects quantization parameters based on real-time macroblock classification (intra, inter, skip, etc.), enabling flexible bit rate adaptation without significantly increasing device complexity. The CPU performs classification and parameter selection based on coding mode information, achieving adaptive control that responds to content characteristics.
Solution Approach 2:
The patent applies local quality by assigning different quantization parameters to different macroblock types and regions within a frame. Instead of using a uniform quantization parameter for the entire frame, the system applies localized quantization strategies tailored to each macroblock's prediction mode and complexity. This allows differentiated bit rate allocation where complex regions receive higher quality treatment while simple regions use aggressive compression.
3Manufacturing precision
If quantization parameter is decreased to maintain picture quality, then compression efficiency deteriorates, but bit rate increases
Solution Approach 1:
The patent resolves this contradiction by changing the quantization parameter based on macroblock classification. The CPU identifies different macroblock types (intra-prediction, inter-prediction, skip modes) and assigns appropriate quantization parameters from a pre-defined table. This adaptive parameter selection ensures that picture quality is maintained in regions requiring it while achieving higher compression efficiency in regions where it can be relaxed, thereby resolving the trade-off between quality and compression efficiency.
Data Source
AI summary
IN a system on chip (SoC) for adaptively adjusting a bit rate, the SoC includes a central processing unit (CPU) configured to compare a first reference bit rate with a bit rate of a previous frame and to output a first parameter, a spatial filter configured to adjust a cutoff frequency using the first parameter, to filter high-frequency components from a current frame using an adjusted cutoff frequency and to output a filtered current frame, and a video codec configured to adjust a bit rate of a current macroblock in the filtered current frame using a second parameter generated according to a result of comparing a second reference bit rate with a bit rate of a previous macroblock in the filtered current frame.