Prototype Filter Indexing for Low-Overhead Parametric EQ Control
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Solution Overview
Problem
Existing audio processing systems for virtual and augmented reality struggle to efficiently control the magnitude response of audio signals, particularly in dynamic environments, due to high computational requirements and inefficiencies in filter control.
Innovation Solution
A system and method using a cascade of shelving filters to create a 3-band parametric equalizer, where gain values are derived from prototype filter parameters and stored in a lookup table, allowing for efficient retrieval and interpolation of magnitude responses for accurate audio signal processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a proportional parametric equalizer with cascade of shelving filters is used for accurate magnitude response control, then audio processing accuracy is improved, but computational overhead and resource consumption increase
Solution Approach 1:
The patent pre-computes and stores filter parameters (gain values, cutoff frequencies, Q factors) in lookup tables before runtime. During actual audio processing, the system only needs to retrieve pre-computed parameters based on current filter settings rather than calculating them in real-time, significantly reducing computational overhead while maintaining accurate magnitude response control
Solution Approach 2:
The patent creates simplified representations of complex filter responses by storing pre-computed magnitude response data in lookup tables. These tabulated copies allow the system to approximate continuous filter behavior using discrete, pre-calculated values, reducing the computational complexity of real-time filter processing while preserving acoustic accuracy
2Adaptability or versatility
If filter parameters are continuously controlled in dynamic AR environments, then audio realism and adaptability are improved, but computing cycles and resources are significantly required
Solution Approach 1:
The system pre-computes filter parameters for a range of possible filter settings and stores them in lookup tables. During dynamic AR environments, the system adapts to changing acoustic conditions by retrieving pre-computed parameters that match current requirements, avoiding the need to calculate new parameters continuously and thus preserving computing cycles for other real-time processing tasks
Solution Approach 2:
The lookup tables store all necessary filter parameters and magnitude response data that the system needs for adaptive processing. The system serves itself by retrieving pre-prepared parameters from these tables based on current operational conditions, eliminating the need for continuous external computation or complex real-time calculations
3Use of energy by moving object
If magnitude response data is fetched from storage at runtime, then computing costs are reduced, but computational overhead is added every time new filter data is needed
Solution Approach 1:
The patent pre-organizes filter parameters and magnitude response data in lookup tables with optimized data structures that enable rapid retrieval. By preparing data in advance and organizing it for efficient access patterns, the system minimizes the time penalty of storage fetching while maintaining low computing costs for parameter retrieval during runtime
Data Source
AI summary
A method of processing an audio signal is disclosed. According to embodiments of the method, magnitude response information of a prototype filter is determined. The magnitude response information includes a plurality of gain values, at least one of which includes a first gain corresponding to a first frequency. The magnitude response information of the prototype filter is stored. The magnitude response information of the prototype filter at the first frequency is retrieved. Gains are computed for a plurality of control frequencies based on the retrieved magnitude response information of the prototype filter at the first frequency, and the computed gains are applied to the audio signal.