Audio Decoder Metadata Control for Dynamic Range and Clipping Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing audio decoding technologies face inefficiencies in dynamic range compression and clipping prevention, particularly due to uncontrolled decoder-side peak limiters that introduce additional delay and computational complexity, and lack of encoder-side control over clipping prevention.
Innovation Solution
The integration of dynamic range control and guided clipping prevention gain sequences within the audio decoder, allowing for separate modification and scaling of gains based on decoder configuration and playback scenarios, enabling encoder-side control of the audio processing chain and potentially eliminating the need for decoder-side peak limiters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a decoder side peak limiter is used for clipping prevention, then clipping is prevented, but additional look-ahead delay and computational complexity are introduced
Solution Approach 1:
The patent applies preliminary action by computing clipping prevention gain sequences at the encoder side before encoding, and transmitting them to the decoder. This allows the decoder to simply apply pre-computed gains without performing complex real-time peak limiting operations, thereby preventing clipping while reducing decoder complexity and delay.
Solution Approach 2:
The patent introduces an intermediary mechanism by using gain sequences as a mediator between the encoder and decoder. The encoder computes and transmits gain sequences that act as intermediate control signals, enabling the decoder to perform simple gain application rather than complex peak limiting, thus resolving the contradiction between clipping prevention and decoder complexity.
2Reliability
If a decoder side peak limiter is used for clipping prevention, then clipping is prevented, but additional look-ahead delay is introduced
Solution Approach 1:
The patent applies preliminary action by computing clipping prevention gain sequences at the encoder side before encoding, and transmitting them to the decoder. This allows the decoder to simply apply pre-computed gains without performing complex real-time peak limiting operations, thereby preventing clipping while reducing decoder complexity and delay.
3Manufacturing precision
If encoder side control of clipping prevention is implemented, then quality requirements are met, but additional metadata transmission is required
Solution Approach 1:
The patent applies the taking out principle by extracting only the essential clipping prevention gain sequences from the full audio processing chain and transmitting them separately as metadata. This allows encoder-side control of clipping prevention quality while minimizing the amount of metadata transmitted, as only the critical gain information is sent rather than complete processing parameters.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention provides a concept for combined dynamic range compression and guided clipping prevention for audio devices. An audio decoder for decoding an audio bitstream and a metadata bitstream related to the audio bitstream according to the concept comprises an audio processing chain configured to receive a decoded audio signal derived from the audio bitstream and to adjust characteristics of the audio signal in order to produce an audio output signal, the audio adjustment chain comprising a plurality of adjustment stages including a dynamic range control stage for adjusting a dynamic range of the audio output signal and a guided clipping prevention stage for preventing clipping of the audio output signal; and a metadata decoder configured to receive the metadata bitstream and to extract dynamic range control gain sequences and guided clipping prevention gain sequences from the metadata bitstream, at least a part of the dynamic range control gain sequences being supplied to the dynamic range control stage, and at least a part of the guided clipping prevention gain sequences being supplied to the guided clipping prevention stage.