Audio Signal Envelope Coding with Cumulative Sum Quantization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current audio signal encoding methods, such as linear predictive coding (LPC) and scale-factor band approaches, face challenges in achieving a smooth and precise spectral envelope while maintaining low bit-rate encoding and reasonable computational complexity.
Innovation Solution
The proposed solution involves distribution quantization and coding of spectral envelopes, which splits the frequency band into equal energy blocks, allowing for efficient encoding and decoding of audio signals by determining aggregation functions and splitting points that divide the signal into portions with balanced energy values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If linear predictive coding (LPC) is used to model the spectral envelope, then the spectral envelope can be represented, but the encoding precision and smoothness of the envelope are insufficient while maintaining low bit-rate
Solution Approach 1:
The patent transforms the spectral envelope representation from traditional LPC parameters to a cumulative sum domain representation. By changing the parameter space and using aggregation functions with coding values, the method achieves higher envelope precision while maintaining low bit-rate through efficient quantization of the transformed parameters.
Solution Approach 2:
The patent introduces a new dimensional representation by using cumulative sum aggregation of spectral coefficients. This transforms the one-dimensional spectral envelope into a cumulative domain where aggregation functions can more efficiently represent the envelope shape, improving precision without proportionally increasing bit-rate.
2Productivity
If traditional spectral envelope encoding methods are used, then the encoding process is simple, but the computational complexity increases and encoding efficiency decreases
Solution Approach 1:
The patent performs preliminary aggregation of spectral coefficients into cumulative sums before encoding. By pre-processing the spectral data into an aggregation function form, the actual encoding process becomes simpler and more efficient, as the aggregation structure naturally captures the envelope characteristics that need to be transmitted.
Solution Approach 2:
The patent divides the spectral envelope representation into discrete aggregation points with coding values. This segmentation allows the encoder to process and transmit only the essential aggregation parameters rather than the complete spectral envelope, reducing computational complexity while maintaining encoding efficiency.
3Measurement precision
If the spectral envelope is encoded with high precision, then the audio quality improves, but the bit-rate increases
Solution Approach 1:
The patent extracts only the essential characteristics of the spectral envelope by representing it through aggregation functions with coding values. Instead of encoding the complete spectral envelope data, the method extracts and transmits only the aggregation parameters that define the envelope shape, achieving high precision with reduced bit-rate.
Data Source
AI summary
An apparatus for generating an audio signal envelope from one or more coding values is provided. The apparatus includes an input interface for receiving the one or more coding values, and an envelope generator for generating the audio signal envelope depending on the one or more coding values. The envelope generator is configured to generate an aggregation function depending on the one or more coding values, wherein the aggregation function includes a plurality of aggregation points. Furthermore, the envelope generator is configured to generate the audio signal envelope such that the envelope value of each of the envelope points of the audio signal envelope depends on the aggregation value of at least one aggregation point of the aggregation function.