Spatial Audio Rendering for Surround Sound From Stereo Downmix
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Solution Overview
Problem
Current methods are unable to generate a surround signal with multi-channel features in environments capable only of producing mono or stereo signals, limiting the processing of media signals effectively.
Innovation Solution
A signal processing apparatus and method that utilize spatial information to convert a downmix signal into a surround signal, using spatial parameters like CLD, ICC, and CPC, and applying rendering information to generate a surround effect, even in devices incapable of recovering multi-channel signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional downmixing methods are used to generate multi-channel signals, then multi-channel features can be recovered, but the method is not usable in devices capable of generating only mono or stereo signals
Solution Approach 1:
The patent introduces spatial information (CLD, ICC, CPC parameters) as an intermediary element that bridges the gap between downmix signals and surround sound output. These spatial parameters act as mediators that enable mono/stereo devices to generate surround signals without requiring full multi-channel decoding capability, thus resolving the contradiction between device compatibility and multi-channel generation reliability
Solution Approach 2:
The patent transforms the downmix signal by applying spatial parameters (CLD for channel level difference, ICC for inter-channel coherence, CPC for channel prediction coefficients) to generate surround signals. This parameter-based transformation allows devices with limited channel capability to produce multi-channel output by modifying signal parameters rather than requiring additional hardware channels
2Adaptability or versatility
If spatial information is used to generate surround signals in mono/stereo capable devices, then multi-channel experience can be created, but the processing complexity increases
Solution Approach 1:
The patent extracts only the essential spatial information parameters (CLD, ICC, CPC) from the original multi-channel signal and transmits them alongside the downmix signal. This extraction approach allows surround signal generation in mono/stereo devices without requiring the full complexity of multi-channel processing, reducing the burden while maintaining adaptability
Solution Approach 2:
The patent segments the spatial information processing into distinct functional components: CLD processing for level balancing, ICC processing for coherence control, and CPC processing for channel prediction. This segmentation allows devices to selectively implement processing based on their capabilities, managing complexity while achieving surround signal generation
Data Source
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AI summary
An apparatus for processing a media signal and method thereof are disclosed, by which the media signal can be converted to a surround signal by using spatial information of the media signal. The present invention provides a method of processing a signal, the method comprising of generating source mapping information corresponding to each source of multi-sources by using spatial information indicating features between the multi-sources; generating at least one rendering information by using the source mapping information and filter information having a surround effect; and performing interpolation by using neighbor rendering information of the at least one rendering information.