Apparatus and Method for Downmixing or Upmixing a Multichannel Signal Using Phase Compensation

Simple SummaryContent extracted from patent full text and abstract with AI.

This invention describes an apparatus and method for improving the downmixing and upmixing of multi-channel (e.g., stereo or surround) audio signals by using a novel phase compensation technique. Rather than processing all audio channels the same way, the system applies more phase rotation to the channel with less energy, helping preserve spatial audio features. It introduces two key parameters, 'side gain' and 'residual gain', to efficiently represent and reconstruct the spatial characteristics during compression and decompression, while keeping the required bitrate low and calculation complexity modest.

Use CasesContent extracted from patent full text and abstract with AI.

• Audio codecs for music streaming and audio file compression (e.g., in streaming platforms, portable music players).
• Surround sound systems and home theaters, enabling improved spatial audio reproduction from compressed signals.
• Hearing aids or audio assistive devices, where low bitrates and low power consumption are important.
• Teleconferencing and video conferencing systems to provide natural-sounding stereo or multi-channel audio over limited bandwidth.
• Mobile devices and embedded systems, where decoding resources and data rates are limited.
• Professional audio and broadcast equipment for high-efficiency archiving and transmission of multi-channel content.

BenefitsContent extracted from patent full text and abstract with AI.

• Enables high-quality spatial audio reconstruction with lower bitrate, saving storage and transmission resources.
• Reduces computational complexity compared to previous parametric approaches, making it suitable for real-time and low-power applications.
• Minimizes artifacts and improves audio quality, particularly for signals with significant phase differences or energy imbalances between channels.
• Flexible design—can be tailored for different time/frequency resolutions depending on application needs.
• Robust quantization scheme for gain parameters, ensuring efficient data packing and consistency.
• Improved compatibility with human auditory perception, as frequency processing takes into account psychoacoustic principles.

Technical Classifications (CPCs)

Inventors & Applicants

Patent Abstract

An apparatus for downmixing a multi-channel signal (100) comprising at least two channels (101, 102), comprises: a downmixer (120) for calculating (34) a downmix signal (122) from the multi-channel signal (100), wherein the downmixer is configured to calculate (34) the downmix using an absolute phase compensation, so that a channel having a lower energy among the at least two channels is only rotated or is rotated stronger than a channel having a greater energy in calculating the downmix signal (122); and an output interface (160) for generating an output signal, the output signal comprising information on the downmix signal (122).