Head-Related Filter Basis Functions for Real-Time Spatial Audio
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for generating head-related filters for spatial audio rendering are inefficient, particularly in terms of computational complexity and memory usage, especially in limited-capacity systems like mobile devices, and often result in inaccurate or ambiguous object locations due to sparsely-sampled measurements or complex interpolation techniques.
Innovation Solution
A method for generating head-related filters using a structured representation of basis functions, including compact sampling and metadata storage to optimize computational complexity and memory usage, allowing efficient HR filter evaluation for any elevation-azimuth angle in real-time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional HR filter generation methods are used, then spatial audio rendering can be achieved, but computational complexity and memory usage are excessively high for mobile devices
Solution Approach 1:
The patent segments the HR filter generation process into distinct stages: (1) measuring impulse responses at a sparse set of discrete locations, (2) generating basis functions from these measurements, (3) storing compact representations with metadata, and (4) evaluating filters by combining basis functions with direction vectors. This segmentation allows computationally intensive operations to be performed once during setup, with efficient real-time evaluation requiring minimal computation.
Solution Approach 2:
The patent performs preliminary actions by pre-measuring impulse responses at discrete locations and pre-generating basis functions before real-time rendering. The basis functions are stored in compact form with metadata that enables efficient retrieval and combination during runtime. This preliminary preparation eliminates the need for complex interpolation during real-time operation, significantly reducing computational complexity.
2Quantity of substance
If sparsely-sampled measurements are used to reduce data size, then memory usage decreases, but object location accuracy becomes ambiguous
Solution Approach 1:
The patent introduces basis functions as intermediary elements that bridge the gap between sparsely-sampled measurements and continuous spatial rendering. These basis functions are generated from the sparse measurements but represent the acoustic field in a continuous mathematical form. During evaluation, the basis functions are combined with direction vectors to produce accurate HR filters for any location, effectively mediating between sparse data and precise spatial accuracy.
Solution Approach 2:
The patent transforms the representation parameters from discrete impulse response measurements to continuous basis function coefficients. By changing the parameter space from raw measurement data to mathematically transformed basis functions, the system achieves both compact storage (reducing memory usage) and continuous spatial accuracy (maintaining object location precision through mathematical evaluation at any direction).
Data Source
AI summary
A method for generating a head-related (HR) filter for audio rendering is provided. The method comprises generating HR filter model data which indicates an HR filter model, and based on the generated HR filter model data, (i) sampling one or more basis functions and (ii) generating first basis function shape data and shape metadata. The method further comprises providing the generated first basis function shape data and the shape metadata for storing in one or more storage mediums.