Video Decoding Using Greatest Coded Line Index Prediction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current video coding technologies face challenges in achieving ultra-low latency and visually lossless compression, especially in broadcast studio environments where high bandwidth is required, leading to increased cable complexity and reduced reliability due to the need for high-speed links and strict rate control.
Innovation Solution
The method involves encoding and decoding greatest coded line index values for video data using a prediction mode and delta values within subbands, along with non-uniform quantization offsets to optimize bit allocation across coefficients, allowing for efficient compression and decompression while maintaining visual quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If uncompressed video data is transported using high-speed links to maintain visual quality, then bandwidth requirements are met, but cable routing complexity increases and reliability decreases
Solution Approach 1:
The video data is segmented into wavelet subbands and further divided into coefficient groups, allowing selective encoding and transmission of only the most significant coefficient groups (those with GCLI values below the truncation threshold). This segmentation enables bandwidth reduction while maintaining visual quality by excluding insignificant data segments.
Solution Approach 2:
The patent extracts and transmits only the greatest coded line index (GCLI) values and their prediction modes for significant coefficient groups, removing unnecessary data elements. By taking out only the essential information needed for reconstruction, the system reduces bandwidth requirements and simplifies cable routing while preserving visual quality.
2Device complexity
If compression is applied to reduce bandwidth requirements, then cable routing is simplified, but latency increases due to processing complexity
Solution Approach 1:
The wavelet transform and coefficient group identification are performed as preliminary actions during encoding, organizing the data into a structured format with predetermined truncation thresholds. This preliminary organization enables the decoder to quickly reconstruct video frames by simply copying and assembling pre-identified significant coefficient groups, minimizing processing time and latency during playback.
Solution Approach 2:
The patent uses copying of GCLI values from previously decoded frames or neighboring coefficient groups through prediction modes. This copying mechanism reduces the amount of data that needs to be transmitted and processed, thereby reducing latency while maintaining compression efficiency.
3Productivity
If rate control is applied to meet latency requirements, then bandwidth utilization is optimized, but visual quality deteriorates due to lossy compression
Solution Approach 1:
The patent applies local quality control by determining separate truncation thresholds for different wavelet subbands based on their visual importance and statistical properties. More significant subbands (e.g., lower frequency components) retain higher precision with fewer coefficients truncated, while less significant subbands (e.g., high frequency components) accept higher truncation. This local differentiation maintains visual quality in critical regions while optimizing bandwidth utilization in less critical regions.
4Quantity of substance
If compression ratio is increased to reduce bandwidth, then cable requirements are simplified, but compression artifacts increase reducing visual quality
Solution Approach 1:
The patent dynamically changes the truncation threshold parameter based on the statistical properties of each wavelet subband, such as the distribution of coefficient magnitudes and the visual importance of different frequency components. By adapting the truncation threshold to local subband characteristics rather than applying a uniform threshold, the system achieves higher compression ratios in tolerant regions while preserving visual quality in sensitive regions, thereby reducing compression artifacts overall.
Data Source
AI summary
A system and method of decoding a set of greatest coded line index values for a precinct of video data from a video bitstream, the precinct of video data including one or more subbands. The method comprises decoding a greatest coded line index prediction mode for each subband from the video bitstream; decoding a plurality of greatest coded line index delta values for each subband from the video bitstream using the greatest coded line index prediction mode for the subband; and producing the greatest coded line index values for each subband using the plurality of greatest coded line index delta values and the greatest coded line index prediction mode for the subband.