DRC Gain Curve Encoding for High-Resolution Audio Compression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current audio codecs, such as MPEG-AAC and ATSC, lack efficient Dynamic Range Control/Compression (DRC) features, leading to limited time resolution and aliasing distortions, particularly in applying DRC gain values, which are essential for maintaining audio quality and reducing dynamic range.
Innovation Solution
A system and method for encoding and applying DRC gain values by dividing them into frames with additional fields representing initial gain values, slope values, time delta values, and gain delta values, allowing for linear or spline interpolation, enabling faster gain changes and reducing distortions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional DRC tools are used in audio codecs, then dynamic range control is achieved, but time resolution is limited and aliasing distortions occur
Solution Approach 1:
The patent segments the audio signal into frames and applies DRC gain values to each frame independently. By dividing the continuous audio signal into discrete temporal segments, the system achieves higher time resolution in applying DRC while maintaining control over aliasing distortions through frame-based processing
Solution Approach 2:
The patent implements dynamic DRC gain adjustment where gain values can change from frame to frame based on the actual audio content. This dynamic adaptation allows the system to respond quickly to transient signals and achieve high time resolution without introducing aliasing, as the gain changes are synchronized with the frame structure
2Object-generated harmful factors
If DRC gain values are encoded with high time resolution, then distortion is reduced, but data rate and complexity increase
Solution Approach 1:
The patent changes the parameter representation of DRC gain values by using differential encoding and frame-based segmentation. Instead of encoding absolute gain values at every sample point, the system encodes gain changes relative to previous frames, significantly reducing the data rate while maintaining high time resolution and minimizing distortions
Solution Approach 2:
The patent applies DRC gain values at frame boundaries rather than at every audio sample point. This partial action approach provides sufficient time resolution to control distortions while avoiding the excessive data rate that would result from sample-by-sample encoding, achieving an optimal balance between distortion reduction and encoding complexity
Data Source
AI summary
A system for encoding and applying Dynamic Range Control/Compression (DRC) gain values to a piece of sound program content is described. In particular, a set of DRC gain values representing a DRC gain curve for the piece of content may be divided into frames corresponding to frames of the piece of content. A set of fields may be included with an audio signal representing the piece of content. The additional fields may represent the DRC gain values using linear or spline interpolation. The additional fields may include 1) an initial gain value for each DRC frame, 2) a set of slope values at particular points in the DRC curve, 3) a set of time delta values for each consecutive pair of slope values, and/or 4) one or more gain delta values representing changes of DRC gain values in the DRC gain curve between points of the slope values.