Audio Loudness Correction Using Downmix Power Ratios
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Solution Overview
Problem
Current audio processing methods face challenges in efficiently managing loudness, especially in next-generation audio systems with object-based audio, where precise loudness measurement and correction are complex due to multiple playback scenarios and formats, requiring frequent measurements and additional bandwidth for multiple language support.
Innovation Solution
The method involves receiving audio data in a first format, processing it to produce a reduced or simplified second format, and performing loudness correction using power ratio-based factors, with linear and non-linear processing operations, including downmixing and K-weighting, to determine and apply loudness correction factors for accurate loudness management across various playback environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If loudness measurements are performed on multiple audio formats and channels to ensure accurate loudness management, then loudness measurement precision is improved, but device complexity and processing time increase
Solution Approach 1:
The patent performs loudness measurements on the original audio data in the first format before downmixing to the second format. By measuring loudness in advance on the full-format audio, the system avoids the need to perform separate measurements on multiple downmixed formats, thereby reducing processing complexity while maintaining measurement precision
Solution Approach 2:
The patent creates a copy of the audio data for loudness measurement purposes, processing the copy rather than the original playback stream. This allows independent loudness analysis without affecting the audio quality or requiring multiple processing streams, reducing overall system complexity
2Adaptability or versatility
If audio data is processed in multiple formats to support various playback scenarios, then adaptability is improved, but processing complexity and bandwidth requirements increase
Solution Approach 1:
The patent performs loudness measurement and correction on the original audio data in the first format before downmixing to the second format. By measuring loudness in advance on the full-format audio, the system avoids the need to perform separate measurements on multiple downmixed formats, thereby reducing processing complexity while maintaining measurement precision
Solution Approach 2:
The patent creates a downmix of the audio data from a first format to a second format, enabling the system to handle multiple playback scenarios through a universal downmixing approach. This single downmixing operation supports various playback configurations without requiring separate processing paths for each format
3Productivity
If loudness correction is applied after downmixing to reduced format, then processing efficiency is improved, but loudness measurement accuracy deteriorates
Solution Approach 1:
The patent performs loudness measurements on the original audio data in the first format before downmixing to the second format. By measuring loudness in advance on the full-format audio, the system avoids the need to perform separate measurements on multiple downmixed formats, thereby reducing processing complexity while maintaining measurement precision
Data Source
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AI summary
Audio data in a first format may be processed to produce audio data in a second format, which may be a reduced or simplified version of the first format. A loudness correction process may produce loudness-corrected audio data in the second format. A first power of the audio data in the second format and a second power of the loudness-corrected audio data in the second format may be determined. A second-format loudness correction factor for the audio data in the second format may be based, at least in part, on a power ratio between the first power and the second power. A first-format loudness correction factor for the audio data in the first format may be based, at least in part, on the power ratio and a power relationship between the audio data in the first format and the audio data in the second format.