Parallel Audio Analysis with Time-Domain Filtering for Low Latency
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Solution Overview
Problem
Conventional audio signal processing systems face a tradeoff between latency, computational complexity, and signal distortion, particularly in real-time processing scenarios, where high latency and harmonic distortions are introduced due to time-to-frequency transforming and critically sampled filterbanks.
Innovation Solution
A system and method for parallel audio signal analysis and processing that filters audio signals in the time domain without time-to-frequency transforming, using a time domain filter controlled by processing parameters determined during analysis, reducing latency and avoiding harmonic distortions while allowing flexible filter design for better band isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If time-to-frequency transforming and filterbanks are used for audio signal analysis, then signal analysis capability is improved, but processing latency increases
Solution Approach 1:
The system separates audio signal processing into two independent parallel paths: analysis path (time-to-frequency transforming) and processing path (time domain filtering). This segmentation allows each path to be optimized independently, with the processing path operating in real-time without waiting for frequency domain analysis results.
Solution Approach 2:
The audio signal is pre-processed in the time domain using a filter before frequency domain transformation. This preliminary time domain filtering reduces the complexity of subsequent frequency domain processing and enables real-time processing without introducing additional latency in the critical processing path.
2Device complexity
If critically sampled filterbanks are used for time-to-frequency transforming, then computational complexity is reduced, but harmonic distortions are introduced
Solution Approach 1:
The harmful harmonic distortion effect is extracted and isolated to only the analysis path where it does not affect the output quality. The processing path uses oversampled filterbanks that do not introduce harmonic distortions, while the analysis path can use computationally efficient critically sampled filterbanks since their distortion output is discarded.
Solution Approach 2:
An intermediary oversampled filterbank is introduced in the processing path between the input signal and the output signal. This intermediary component ensures high-quality processing without harmonic distortions while the analysis path handles computational complexity independently.
3Reliability
If filterbanks are designed for perfect reconstruction, then signal reconstruction quality is improved, but band isolation performance deteriorates
Solution Approach 1:
The system segments the filterbank design requirements into two separate paths: the processing path uses filterbanks optimized for perfect reconstruction to ensure high-quality output, while the analysis path uses filterbanks optimized for band isolation to improve analysis accuracy. Each path's filterbank design priorities are independent and do not conflict.
Data Source
AI summary
Example embodiments disclosed herein relate to separated audio analysis and processing. A system for processing an audio signal is disclosed. The system includes an audio analysis module configured to analyze an input audio signal to determine a processing parameter for the input audio signal, the input audio signal being represented in time domain. The system also includes an audio processing module configured to process the input audio signal in parallel with the audio analysis module. The audio processing module includes a time domain filter configured to filter the input audio signal to obtain an output audio signal in the time domain, and a filter controller configured to control a filter coefficient of the time domain filter based on the processing parameter determined by the audio analysis module. Corresponding method and computer program product of processing an audio signal are also disclosed.