Downmix Audio Rendering Using Spatial Cues for Surround Playback

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Solution Overview

Problem

Current methods and apparatuses 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 method and apparatus that utilize spatial information to convert a media signal into a surround signal by generating source mapping information, applying filter information for a surround effect, and integrating rendering information with a downmix signal to produce the surround signal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional methods are used to generate multi-channel signals, then multi-channel features are achieved, but the method is unusable in devices capable of generating only mono or stereo signals

Engineering Contradiction:
Improvecompatibility with mono/stereo devicesVSAvoidsurround signal generation capability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent introduces an intermediary process that extracts spatial information from multi-channel signals and applies it to downmix signals through filter banks. This mediator enables surround effect generation in mono/stereo devices without requiring full multi-channel capability, resolving the contradiction between device capability and surround effect requirement

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the parameter representation by using spatial information (inter-channel level difference, inter-channel time difference, inter-channel coherence) to control filter bank operations. This allows the system to adapt to different device capabilities while maintaining surround effect generation through parameter adjustment rather than structural change

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If spatial information is used to generate surround signals in limited-capability devices, then surround effects are achieved, but the processing complexity increases

Engineering Contradiction:
Improvesurround signal generation in mono/stereo devicesVSAvoidprocessing complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the processing into distinct modules: spatial information extraction, filter bank application, and downmix signal processing. This segmentation allows each module to be optimized independently and enables selective implementation based on device capability, reducing overall processing complexity while maintaining surround effect generation

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by selectively processing only the necessary components (downmix signal with spatial information) rather than processing the entire multi-channel signal. This partial processing reduces computational complexity while still achieving the desired surround effect in limited-capability devices

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP1974348B1Method and apparatus for processing a media signal
Publication Date: 2013.07.24 LG ELECTRONICS INC
  • EP1974348B1 patent drawingFigure 1~2
  • EP1974348B1 patent drawingFigure 3~4
  • EP1974348B1 patent drawingFigure 5~7

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 extracting spatial information and a downmix signal from a bitstream; and generating rendering information by using the spatial information and filter information having a surround effect, wherein the rendering information comprises first rendering information applied to one channel of the downmix signal extracted from the bitstream and then transmitted on the same channel and second rendering information applied to the channel and then transmitted on another channel.