Adaptive IPD Encoding for Stereo Phase Precision and Efficiency
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Solution Overview
Problem
Existing IPD parameter encoding methods in stereo audio encoding are inefficient in resource usage and lack precision, leading to poor encoding quality due to either excessive resource consumption or low phase information precision.
Innovation Solution
An IPD parameter encoding method that adaptively selects an encoding scheme based on reference parameters, including signal characteristics of the current and previous frames, to optimize encoding efficiency and quality by dynamically determining whether to encode or set the IPD parameter to 0, or use a group IPD parameter encoding scheme.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If IPD parameters of all subbands are calculated and quantized one by one, then phase information precision is improved, but resource consumption increases and encoding efficiency decreases
Solution Approach 1:
The patent segments the frequency domain signal into multiple subbands and processes them differently. Instead of uniformly processing all subbands, it divides them into groups and applies selective encoding based on correlation thresholds, thereby reducing overall processing complexity while maintaining precision where needed.
Solution Approach 2:
The patent applies different encoding strategies to different subband groups based on their local characteristics (correlation values). High-correlation subbands use one encoding approach while low-correlation subbands use another, optimizing the balance between precision and efficiency for each local region of the frequency spectrum.
2Productivity
If only one group IPD parameter is calculated for the entire frame, then resource consumption is reduced and encoding efficiency is improved, but phase information precision deteriorates
Solution Approach 1:
The patent divides the frequency spectrum into multiple subband groups rather than treating the entire frame as a single group. This segmentation allows for more granular control over phase information encoding, improving precision without requiring processing of every individual subband.
Solution Approach 2:
The patent performs partial processing by selecting only certain subband groups for detailed IPD parameter calculation based on correlation thresholds. Not all subbands are processed with full precision, but enough are processed to maintain overall phase information quality while reducing total computational effort.
3Reliability
If adaptive IPD parameter encoding scheme selection is implemented, then encoding quality is improved, but device complexity increases
Solution Approach 1:
The patent implements dynamic selection of IPD parameter encoding schemes based on real-time analysis of subband correlation characteristics. The encoding approach adapts to the content of each frame and even each subband group, improving quality while keeping the decision logic relatively simple through threshold-based classification.
Solution Approach 2:
The patent changes encoding parameters (such as whether to encode IPD parameters at all, or how to quantize them) based on the calculated correlation values of subband groups. This parameter adaptation allows quality optimization without requiring a complete overhaul of the encoding architecture.
Data Source
AI summary
The present disclosure discloses an inter-channel phase difference parameter encoding method, where a current frame is obtained; a signal type and a previous IPD parameter encoding scheme of a previous frame are obtained; a current IPD parameter encoding scheme is obtained at least based on the signal type of the previous frame and the previous IPD parameter encoding scheme; and an IPD parameter of the current frame is processed based on the current IPD parameter encoding scheme.