Audio Signal Processing Using Complex FDNS Synthesis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current audio coding techniques face limitations in achieving high sound quality at low bit rates, particularly in preserving frequency domain information and efficiently compressing audio signals without distortion.
Innovation Solution
An audio signal processing device and method that performs inverse quantization, Frequency Domain Noise Shaping (FDNS) synthesis, and frequency-to-time transform to generate restored audio signals, with options for Temporal Noise Shaping (TNS) and switching compensation to manage noise and aliasing, ensuring efficient compression and sound quality preservation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If audio coding compresses audio signals to reduce bit rate, then compression efficiency is improved, but sound quality deteriorates due to loss of frequency domain information
Solution Approach 1:
The patent transforms audio signals from time domain to frequency domain using MDCT, changing the representation parameters to expose spectral information that can be more efficiently compressed while preserving perceptual quality. The frequency domain representation allows for targeted quantization that maintains sound quality at lower bit rates.
Solution Approach 2:
The patent applies different quantization precision to different frequency bands based on psychoacoustic masking thresholds. Critical frequency regions receive higher precision while less critical regions use coarser quantization, optimizing the balance between compression efficiency and perceived sound quality.
2Productivity
If quantization is applied to compress audio data, then compression efficiency is improved, but distortion increases due to loss of signal fidelity
Solution Approach 1:
The patent exploits psychoacoustic masking effects where certain frequency components mask others, converting the potential harm of quantization distortion into a benefit by removing or coarsely quantizing masked components that would be imperceptible, thereby improving compression efficiency without noticeable quality loss.
Solution Approach 2:
The patent introduces scale factors as intermediaries that control the quantization precision for different frequency bands. These scale factors act as mediators between the original signal and quantized values, allowing adaptive precision control that minimizes perceptible distortion while maximizing compression.
3Manufacturing precision
If Frequency Domain Noise Shaping is applied to preserve sound quality, then sound quality is improved, but computational complexity increases
Solution Approach 1:
The patent divides the frequency spectrum into multiple bands and applies noise shaping independently to each band. This segmentation reduces the computational complexity of processing the entire spectrum at once while maintaining the sound quality benefits of noise shaping through localized optimization.
Data Source
AI summary
Disclosed are a device and method for audio signal processing. The audio signal processing device according to an embodiment includes a receiver configured to receive a bitstream corresponding to a compressed audio signal and a processor. The processor may be configured to generate a real restoration signal or a complex restoration signal by performing inverse quantization on real data of the bitstream or complex data of the bitstream, generate a result of real Frequency Domain Noise Shaping (FDNS) synthesis or a result of complex FDNS synthesis by performing FDNS synthesis on the real restoration signal or the complex restoration signal, and generate a restored audio signal by performing frequency-to-time transform on the result of the real FDNS synthesis or the result of the complex FDNS synthesis.