Selective Phase Information Transmission in Audio Encoding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing audio encoding and decoding schemes face challenges in achieving high reconstruction quality without significantly increasing bitrate, particularly in the transmission of phase information, which is crucial for maintaining perceptual quality in multi-channel audio signals.
Innovation Solution
The use of a phase estimator to derive phase information only when necessary, based on a predetermined threshold, and incorporating this information into the encoded representation along with spatial parameters like ICC and ILD, allows for selective transmission of phase data, ensuring high quality reconstruction with minimal additional bitrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If phase information is transmitted for all time segments, then reconstruction quality is improved, but bitrate increases
Solution Approach 1:
The patent applies local quality by transmitting phase information selectively only in time segments where it is perceptually relevant, rather than uniformly across all segments. The encoder determines local relevance based on signal characteristics such as signal level and spectral content, applying phase transmission only where needed to maintain reconstruction quality while reducing overall bitrate.
Solution Approach 2:
The patent implements partial action by transmitting phase information for only a subset of time segments rather than all segments. The encoder evaluates each segment individually and transmits phase data only when the signal characteristics indicate perceptual relevance, achieving sufficient reconstruction quality with reduced data transmission.
2Quantity of substance
If phase information is omitted to reduce bitrate, then bitrate is reduced, but reconstruction quality deteriorates
Solution Approach 1:
The patent changes the parameter of phase information transmission from a constant state (always transmitted or never transmitted) to a variable state determined by signal characteristics. The encoder monitors parameters such as signal level, spectral content, and temporal variations to dynamically decide whether to transmit phase information in each time segment, optimizing the quality-bitrate trade-off.
Solution Approach 2:
The patent introduces dynamics into the phase transmission system by making the transmission decision adaptive to changing signal conditions. The encoder continuously evaluates signal characteristics and adjusts phase transmission accordingly, transitioning between transmitting and omitting phase information based on real-time signal analysis.
3Quantity of substance
If phase information is transmitted selectively based on signal characteristics, then bitrate is reduced, but complexity of determining when to transmit increases
Solution Approach 1:
The patent applies preliminary action by performing signal characteristic analysis during the encoding phase to pre-determine which time segments require phase information transmission. The encoder evaluates signal properties in advance and prepares transmission decisions before actual phase data transmission, simplifying the overall system architecture.
Solution Approach 2:
The patent introduces an intermediary decision-making mechanism that mediates between the raw signal and the phase transmission process. The encoder acts as an intermediary, analyzing signal characteristics and determining transmission necessity based on perceptual relevance criteria, thereby simplifying the complexity of the overall system.
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
An efficient encoded representation of a first and a second input audio signal can be derived using correlation information indicating a correlation between the first and the second input audio signals, when a signal characterization information, indicating at least a first or a second, different characteristic of the input audio signal is additionally considered. Phase information indicating a phase relation between the first and the second input audio signals is derived, when the input audio signals have the first characteristic. The phase information and a correlation measure are included into the encoded representation when the input audio signals have the first characteristic, and only the correlation information is included into the encoded representation when the input audio signals have the second characteristic.