Spatial Audio Parameter Merging Across Time-Frequency Bands
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing spatial audio codecs face challenges in efficiently compressing spatial metadata at varying bit rates, particularly at lower bitrates, due to the high raw bitrate of encoded parameters, necessitating a need for apparatus and methods to optimize the encoding and decoding of spatial audio signals while maintaining quality.
Innovation Solution
The proposed solution involves determining a merge metric to control the merging of spatial audio signal parameter values over the time-frequency domain, using onset metrics and energy ratios to reduce the number of spatial audio signal parameter values, and employing quantization and entropy encoding to optimize compression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If spatial audio signal parameter values are encoded for each time-frequency domain element, then audio quality is maintained, but bitrate becomes excessively high
Solution Approach 1:
The patent merges spatial audio signal parameter values across time and frequency domains by determining representative parameter values for groups of time-frequency domain elements. This combining approach reduces the total number of parameters that need to be encoded and transmitted, thereby reducing bitrate while maintaining perceptual audio quality through intelligent parameter selection and merging strategies.
Solution Approach 2:
The patent applies different merging strategies to different time-frequency domain elements based on local characteristics such as energy ratios and onset detection. By adaptively selecting which parameters to merge and which to preserve in each local region, the system maintains high spatial audio quality where needed while reducing bitrate in less critical regions.
2Productivity
If spatial metadata is compressed to reduce bitrate, then transmission efficiency improves, but spatial audio quality deteriorates
Solution Approach 1:
The patent implements dynamic merging where the merging of spatial audio signal parameter values is controlled adaptively based on local time-frequency characteristics. The system dynamically determines which parameters to merge and which to preserve by analyzing energy ratios and detecting onsets, allowing flexible adjustment between compression ratio and quality preservation based on the actual audio content.
Solution Approach 2:
The patent changes parameters such as merge metrics, energy ratios, and onset detection thresholds to optimize the balance between compression efficiency and spatial audio quality. By adjusting these parameters adaptively, the system can achieve better transmission efficiency when quality requirements are lower and maintain higher quality when needed.
3Quantity of substance
If merging of spatial audio signal parameter values is applied, then bitrate is reduced, but parameter representation accuracy decreases
Solution Approach 1:
The patent performs preliminary analysis of spatial audio signal parameter values in the time-frequency domain before merging, by calculating energy ratios and detecting onsets. This preliminary action allows the system to identify which parameters should be preserved and which can be merged, ensuring that merging operations are performed intelligently to maintain parameter representation accuracy while still achieving bitrate reduction.
Solution Approach 2:
The patent uses feedback from energy ratio calculations and onset detection results to control the merging process. The merge metrics are determined based on feedback from the local time-frequency characteristics, allowing the system to adaptively adjust merging decisions to maintain parameter accuracy while reducing bitrate.
Data Source
AI summary
An apparatus comprising means configured to: obtain at least one audio signal; obtain, for the at least one audio signal, spatial audio signal parameter values, the spatial audio signal parameters values distributed within a time-frequency domain (106); determine a merge metric to control a merging of the spatial audio signal parameter values over the time-frequency domain (201); and merge (203), based on the merge metric (202), the spatial audio signal parameter values to a smaller number of spatial audio signal parameter values overtime and/or frequency within the time-frequency domain.