Multi-Channel Audio Representation Using Channel-Pair Balance Parameters
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multi-channel audio coding techniques, such as Binaural Cue Coding, require each inter-channel level difference for perfect reconstruction, making them error-prone and inefficient, especially in scenarios with fewer important channels like surround channels, and are unnatural for human listening as they rely on a single reference channel.
Innovation Solution
The proposed solution introduces a multi-balance concept using balance parameters between different channel pairs, allowing for flexible and scalable coding that reconstructs channels without requiring all inter-channel level differences, using balance parameters like left/right, center, and front/back balances, and incorporating information from the down-mixing scheme for up-mixing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If Binaural Cue Coding is used to represent multi-channel audio signals, then the bit rate is reduced, but the reconstruction becomes error-prone and requires all inter-channel level differences for perfect reconstruction
Solution Approach 1:
The patent changes the parameter representation from absolute inter-channel level differences (ICLD) to relative balance parameters between channel pairs. This transformation allows the system to achieve both compression and robustness by representing spatial relationships in a more efficient and error-tolerant manner, where not all parameters are required for reconstruction of all channels.
Solution Approach 2:
The patent segments the multi-channel audio representation into independent channel pairs, each characterized by its own balance parameters. This segmentation allows the system to process and reconstruct channels independently based on available parameters, improving both bit rate efficiency and reconstruction reliability by not requiring complete parameter sets.
2Measurement precision
If all inter-channel level differences are transmitted for perfect reconstruction, then the reconstruction accuracy is improved, but the bit rate increases
Solution Approach 1:
The patent extracts only the essential balance parameters needed for practical reconstruction, removing redundant information. By taking out only the critical parameters (balance parameters between channel pairs) and discarding less important details, the system achieves good reconstruction accuracy at lower bit rates, especially when surround channels are less critical.
Solution Approach 2:
The patent applies partial action by transmitting a subset of parameters rather than the complete set of inter-channel level differences. The system achieves satisfactory reconstruction quality with partial parameter information, particularly when certain channels (like surround channels) are less important, thereby reducing bit rate while maintaining acceptable accuracy.
3Device complexity
If a single reference channel is used for Binaural Cue Coding, then the parameter calculation is simplified, but the representation becomes unnatural for human listening
Solution Approach 1:
The patent makes the channel pair balance parameters universal and interchangeable, allowing any channel to serve as a reference depending on the pairing. This multi-functional approach eliminates the limitation of a single fixed reference channel, enabling more natural sound impressions while maintaining calculation simplicity through the symmetric balance parameter formulation.
4Adaptability or versatility
If the system must decode all channels before down-mixing, then the channel configuration flexibility is improved, but the processing time increases
Solution Approach 1:
The patent performs preliminary extraction of balance parameters from the multi-channel signal before any decoding or down-mixing operations. This preliminary action allows the system to quickly adapt to different channel configurations by selecting and applying the relevant balance parameters, avoiding the need to fully decode all channels first and thereby reducing processing time while maintaining configuration flexibility.
Data Source
AI summary
A multi-channel input signal having at least three original channels is represented by a parameter representation of the multi-channel signal. A first balance parameter, a first coherence parameter, or a first inter-channel time difference between a first channel pair and a second balance parameter, or a second coherence parameter, or a second inter-channel time difference parameter between a second channel pair are calculated. This set of parameters is the parameter representation of the original signals. The first channel pair has two channels, which are different from two channels of a second channel pair. Furthermore, each channel of the two channel pairs is one of the original channels, or a weighted combination of the original channels, and the first channel pair and the second channel pair include information on the three original channels. For multi-channel reconstruction purposes, the parameters are used in addition to down-mixing information to generate a selectable number of output channels in a scalable fashion.