Methods and equipment for decompressing high-order ambisonics signals that have been compressed, and invariant media read by computers

Abstract

The invention relates to a method and apparatus for decompressing compressed higher-order ambisonic (HOA) signals. Higher-order ambisonic (HOA) signals represent the complete sound field in the vicinity of the sharp point, independent of loudspeaker settings. High spatial resolution requires a large HOA coefficient. According to the invention, the principal acoustic directions are estimated and the HOA signal representation is analyzed into principal directional signals in the time domain and associated directional information, and surrounding components in the HOA domain, followed by compression of the surrounding component by reducing its order. The reduced-order surrounding component is transformed to the spatial domain and perceptually encoded along with the directional signals. At the receiver side, the encoded directional signals and their surrounding reduced-order encoded components are desensitized. The desensitized surrounding signals are transformed into a signal domain representation with a reduced order, and then scaled up. The overall HOA signal representation is then reconstructed from the directional signals, corresponding directional information, and the original order surrounding HOA components.