Audio Decoder DRC Profiles for Output-Level Adaptive Rendering
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Solution Overview
Problem
Existing audio signal processing technologies face challenges in maintaining high-quality and intelligibility across a broad range of rendering devices with different capabilities and environments, as they often fail to adapt dynamic range appropriately, leading to distortion or inaudibility.
Innovation Solution
A method and system for transmitting Dynamic Range Control (DRC) profiles in a bandwidth-efficient manner by inserting multiple DRC profiles into audio frames, allowing an audio decoder to select the appropriate profile for the specific rendering mode, ensuring high-quality and intelligible audio reproduction across various playback environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single fixed dynamic range is used for audio encoding, then the encoding is simple and bandwidth-efficient, but the audio quality and intelligibility deteriorate across different rendering devices and environments
Solution Approach 1:
The audio encoding system segments the dynamic range control into multiple discrete DRC profiles, each optimized for specific rendering modes (e.g., television, cinema, headphones). Instead of transmitting a single fixed dynamic range, the encoder transmits multiple segmented profiles that the decoder can select based on the rendering device type, thereby achieving adaptability without requiring a completely complex system redesign
Solution Approach 2:
The system introduces dynamic selection capability where the DRC profile is not fixed but can be dynamically chosen based on the rendering mode. The decoder determines the appropriate DRC profile from the transmitted set based on the specific playback environment, enabling the system to adapt dynamically between different device requirements while maintaining a manageable structure through predefined profile options
2Reliability
If multiple DRC profiles are transmitted for different rendering modes, then audio quality across devices is improved, but the bandwidth consumption increases
Solution Approach 1:
The system extracts and transmits only the essential DRC profile parameters rather than complete audio signals for each rendering mode. By taking out just the critical dynamic range control data (compression curves, gain values, rendering mode identifiers) and transmitting these extracted elements, the system achieves reliable audio quality adaptation while minimizing bandwidth consumption compared to transmitting full audio tracks for each mode
Solution Approach 2:
The system changes the parameter representation by transmitting DRC profiles as compressed parameter sets rather than full audio signals. Each profile is represented by key parameters (dynamic range compression curves, gain adjustments, rendering mode tags) that can be efficiently encoded and transmitted. This parameter-based approach maintains audio quality reliability while significantly reducing the bandwidth required compared to transmitting complete audio content for each rendering scenario
3Object-affected harmful factors
If dynamic range is limited for portable devices, then distortion is prevented, but audio quality for high-end systems is compromised
Solution Approach 1:
The system applies local quality optimization by providing different DRC profiles tailored to specific rendering device categories. Portable devices receive DRC profiles with aggressive compression to prevent distortion and ensure intelligibility in noisy environments, while high-end systems receive profiles with minimal compression to preserve audio quality and dynamic range. Each device type gets the locally optimized profile appropriate to its capabilities and typical usage environment
Solution Approach 2:
The system enables dynamic adaptation where the degree of dynamic range compression is not fixed but changes based on the rendering device. The decoder dynamically selects between different compression levels - high compression for portable devices to prevent distortion, and low compression for high-end systems to maintain audio fidelity. This dynamic approach allows the same encoded audio stream to serve multiple device types with appropriate quality levels without compromising either portable device performance or high-end system capability
Data Source
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AI summary
A method for decoding an encoded audio signal, wherein the encoded audio signal comprises a sequence of frames comprising encoded audio data and metadata, the metadata including a plurality of different sets of dynamic range control, DRC, gains, wherein the encoded audio signal further comprises an indication of a loudness level of the audio signal, wherein the metadata indicates a plurality of DRC profiles for the encoded audio signal, wherein each DRC profile comprises definition data defining a range of output reference levels for which the DRC profile is applicable, and wherein each set of DRC gains corresponds to one of the plurality of DRC profiles, the method comprisingsetting a desired output reference level;selecting a DRC profile for which the applicable range of output reference levels includes the desired output reference level;extracting audio data from the encoded audio signal;applying the DRC gains corresponding to the selected DRC profile to the extracted audio data to adjust the dynamic range of the extracted audio data;determining a loudness related gain based on the indication of the loudness level of the audio signal and the desired output reference level to cause a change from the loudness level of the audio data to the desired output reference level; andapplying the loudness related gain to the dynamic range adjusted audio data to obtain loudness adjusted audio data that has the desired output reference level.