Audio Codec Noise Parameterization for Seamless Phase Transitions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current audio codecs fail to efficiently reduce transmission bitrate during inactive phases while maintaining noise generation quality, leading to increased computational complexity and bitrate consumption.
Innovation Solution
The proposed audio codec utilizes spectral domain parameterization of background noise, allowing continuous update during active phases to enable seamless transition to inactive phases without additional bitrate overhead, thereby reducing transmission bitrate and maintaining noise quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional noise estimation methods are used during inactive phases, then transmission bitrate is reduced by stopping ordinary data stream transmission, but noise generation quality deteriorates leading to unpleasant transitions from active to inactive phases
Solution Approach 1:
The system continuously updates the parametric background noise estimate during active phases before inactive phases occur. This preliminary action ensures that when transmission stops during inactive phases, the decoder already has current noise parameters to generate realistic comfort noise, avoiding unpleasant transitions while maintaining bitrate reduction.
Solution Approach 2:
The invention changes from time-domain noise estimation to spectral-domain parameterization. By representing background noise through spectral parameters (magnitude and phase spectra) rather than time-domain samples, the system achieves more efficient parameter transmission and update during active phases, enabling better noise reconstruction during inactive phases with lower bitrate.
2Reliability
If a warm-up phase is introduced to provide coded background noise representation to the decoding side, then noise generation quality improves, but transmission bitrate increases due to preliminary encoding overhead
Solution Approach 1:
Instead of introducing a warm-up phase during inactive periods, the system performs preliminary noise estimation continuously during active phases. The encoder and decoder both maintain up-to-date parametric noise estimates while audio is being transmitted, eliminating the need for subsequent warm-up phases that would consume additional bitrate during inactive phases.
Solution Approach 2:
The system uses the existing active phase transmission to serve dual purposes: delivering audio content and simultaneously updating noise parameters. The ordinary data stream transmission during active phases carries both audio information and noise estimation updates, eliminating the need for separate warm-up phase transmissions.
3Reliability
If spectral domain parameterization is used for background noise, then noise synthesis realism improves and transition transparency increases, but computational complexity increases
Solution Approach 1:
The invention transforms noise representation from time-domain waveforms to spectral-domain parameters (magnitude and phase spectra). This parameterization enables more efficient computation of noise characteristics, as spectral parameters capture essential noise properties with fewer data points, reducing computational complexity while improving synthesis realism.
Solution Approach 2:
The system extracts only the essential spectral parameters (magnitude and phase) from the full audio signal during active phases, rather than processing or transmitting complete time-domain waveforms. This extraction approach reduces computational complexity by focusing only on the critical noise characteristics needed for realistic synthesis during inactive phases.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The spectral domain is efficiently used in order to parameterize the background noise thereby yielding a background noise synthesis which is more realistic and thus leads to a more transparent active to inactive phase switching.