Audio Gain Interpolation Decoding for Smooth Frame Transitions

Solution Overview

Problem

Existing audio coding techniques, such as MPEG AAC, face issues with discontinuous temporal waveforms in audio signals due to uniform gain correction across frames, leading to degradation in sound quality when significant gain changes occur between frames.

Innovation Solution

A decoding apparatus and method that reads encoded gain values at multiple sample positions and uses interpolation information to apply either linear or non-linear interpolation to smooth gain changes between frames, ensuring each sample within a frame can have a designated gain value, thereby reducing discontinuities and improving sound quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If uniform gain correction is applied across all samples within one frame, then the decoding process is simple and efficient, but discontinuities occur in temporal waveforms when gain changes significantly between frames, degrading sound quality

Engineering Contradiction:

Improvedecoding process complexityVSAvoidtemporal waveform continuity

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The frame is divided into multiple sub-segments, and different interpolation methods (linear or non-linear) are applied to different sub-segments based on local characteristics. This segmentation allows the system to maintain simplicity in low-gain-change regions while applying complex interpolation only where necessary, thus resolving the contradiction between decoding complexity and waveform continuity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent dynamically selects between linear and non-linear interpolation methods based on the actual gain change characteristics between frames. When gain changes are small, simple linear interpolation is used; when gain changes are large, non-linear interpolation is applied. This dynamic adaptation resolves the contradiction by adjusting the decoding complexity according to the actual need for waveform continuity.

Inventive Principle:

Principle #15Dynamics

2Reliability

If non-linear interpolation is used to smoothly connect gain values between frames, then temporal waveform continuity is improved, but the decoding process becomes more complex and computationally intensive

Engineering Contradiction:

Improvetemporal waveform continuityVSAvoidinterpolation processing complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent dynamically selects between linear and non-linear interpolation methods based on the actual gain change characteristics between frames. When gain changes are small, simple linear interpolation is used; when gain changes are large, non-linear interpolation is applied. This dynamic adaptation resolves the contradiction by adjusting the decoding complexity according to the actual need for waveform continuity.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The frame is divided into multiple sub-segments, and different interpolation methods (linear or non-linear) are applied to different sub-segments based on local characteristics. This segmentation allows the system to maintain simplicity in low-gain-change regions while applying complex interpolation only where necessary, thus resolving the contradiction between decoding complexity and waveform continuity.

Inventive Principle:

Principle #3Local quality

3Reliability

If gain values are corrected at every sample position, then sound quality is maximized, but the code amount increases significantly

Engineering Contradiction:

Improvesound qualityVSAvoidcode amount

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent extracts and transmits only the essential gain parameters (gain values at specific positions and interpolation method indicators) rather than transmitting gain values for every sample position. The receiver then reconstructs the complete gain sequence through interpolation. This extraction approach significantly reduces code amount while maintaining sound quality by preserving the essential gain information needed for accurate reconstruction.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of transmitting all gain values, the patent transmits a compressed representation (copy) of the gain information at key positions, and the receiver generates the complete gain sequence by copying and interpolating from these sampled positions. This copying approach reduces code amount while maintaining the ability to reconstruct high-quality gain values at all sample positions.

Inventive Principle:

Principle #26Copying

Data Source

PatentUS11705140B2Decoding apparatus and method, and program

Publication Date: 2023.07.18 SONY GROUP CORP

AI summary

The present technology relates to a decoding apparatus, a decoding method and a program which make it possible to obtain sound with higher quality.A demultiplexing circuit demultiplexes an input code string into a gain code string and a signal code string. A signal decoding circuit decodes the signal code string to output a time series signal. A gain decoding circuit decodes the gain code string. That is, the gain decoding circuit reads out gain values and gain inclination values at predetermined gain sample positions of the time series signal and interpolation mode information. An interpolation processing unit obtains a gain value at each sample position between two gain sample positions through linear interpolation or non-linear interpolation according to the interpolation mode based on the gain values and the gain inclination values. A gain applying circuit adjusts a gain of the time series signal based on the gain values. The present technology can be applied to a decoding apparatus.