Audio Encoder Algorithm Selection by Estimated Quality Measures
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing switched audio coders face complexity challenges in selecting between different encoding algorithms for audio signals, with open-loop mode selection performing worse than closed-loop methods but reducing complexity, and existing solutions rely on feature calculation and statistical evaluation rather than estimating quality measures directly.
Innovation Solution
An apparatus and method that estimate quality measures for each encoding algorithm, such as segmental SNR, without actual encoding and decoding, allowing for mode selection based on these estimates, similar to closed-loop methods but with reduced complexity, using estimators and a controller to choose between algorithms like ACELP and TCX.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If closed-loop mode selection is used to select encoding algorithms, then the decision stability and robustness are improved, but the computational complexity increases significantly
Solution Approach 1:
The patent creates a simplified model (copy) of the encoding process that estimates quality measures without performing actual encoding and decoding. This model copies only the essential computational elements needed to predict quality, avoiding the full encoding/decoding cycle while maintaining decision accuracy comparable to closed-loop methods.
Solution Approach 2:
The patent performs preliminary estimation of quality measures for both encoding algorithms before final mode selection. By calculating estimated quality measures in advance using the simplified model, the system prepares decision-critical information beforehand, enabling fast and accurate mode selection without requiring complete encoding/decoding cycles at decision time.
2Device complexity
If open-loop mode selection is used to reduce complexity, then the computational complexity is reduced, but the decision quality deteriorates
Solution Approach 1:
The patent creates a simplified model that copies the essential quality assessment functionality without the full encoding/decoding process. This allows open-loop operation with significantly reduced complexity while maintaining decision quality comparable to closed-loop methods through accurate quality measure estimation.
Solution Approach 2:
The patent incorporates feedback mechanisms where the estimated quality measures from the simplified model are used to guide mode selection decisions. The system continuously adapts its mode selections based on these estimated quality feedback signals, improving decision quality while maintaining low computational complexity through iterative refinement rather than complete re-encoding.
3Device complexity
If feature calculation and statistical evaluation are used for mode selection, then the complexity is reduced, but the performance is worse compared to closed-loop methods
Solution Approach 1:
Instead of using simplified feature calculations that lose information, the patent copies the essential quality assessment functionality of the full encoding model into a simplified estimation framework. This preserves the relationship between input features and quality outcomes while reducing computational load, maintaining mode selection accuracy that feature-based methods cannot achieve.
Data Source
AI summary
An apparatus for selecting one of a first encoding algorithm having a first characteristic and a second encoding algorithm having a second characteristic for encoding a portion of an audio signal to obtain an encoded version of the portion of the audio signal has a first estimator for estimating a first quality measure for the portion of the audio signal, which is associated with the first encoding algorithm, without actually encoding and decoding the portion of the audio signal using the first encoding algorithm. A second estimator is provided for estimating a second quality measure for the portion of the audio signal, which is associated with the second encoding algorithm, without actually encoding and decoding the portion of the audio signal using the second encoding algorithm. The apparatus has a controller for selecting the first or second encoding algorithms based on a comparison between the first and second quality measures.