Method and apparatus for compressing and decompressing a Higher Order Ambisonics signal representation
A method and apparatus for decompressing a Higher Order Ambisonics (HOA) signal representation is disclosed. The apparatus includes an input interface that receives an encoded directional signal and an encoded ambient signal and an audio decoder that perceptually decodes the encoded directional signal and encoded ambient signal to produce a decoded directional signal and a decoded ambient signal, respectively. The apparatus further includes an extractor for obtaining side information related to the directional signal and an inverse transformer for converting the decoded ambient signal from a spatial domain to an HOA domain representation of the ambient signal. The apparatus also includes a synthesizer for recomposing a Higher Order Ambisonics (HOA) signal from the HOA domain representation of the ambient signal and the decoded directional signal. The side information includes a direction of the directional signal selected from a set of uniformly spaced directions.
1. A method for decompressing a compressed Higher Order Ambisonics (HOA) signal that includes an encoded directional signal and an encoded ambient signal, the method comprising:
receiving the compressed HOA signal;
obtaining side information related to the encoded directional signal, wherein the side information includes a direction of the directional signal selected from a set of uniformly spaced directions;
perceptually decoding the compressed HOA signal based on the side information to produce a decoded directional HOA signal and a decoded ambient HOA signal;
performing order extension on the decoded ambient HOA signal to obtain a representation of the decoded ambient HOA signal; and
recomposing a decoded HOA representation from the representation of the decoded ambient HOA signal and the decoded directional HOA signal.
2. The method of claim 1 wherein the decoded HOA representation has an order greater than one.
3. The method of claim 2 wherein the order of the decoded ambient HOA signal is less than the order of the decoded HOA representation.
4. An apparatus for decompressing a compressed Higher Order Ambisonics (HOA) signal that includes an encoded directional signal and an encoded ambient signal, the apparatus comprising:
an input interface that receives the compressed HOA signal;
a first processor for obtaining side information related to the encoded directional signal, wherein the side information includes a direction of the directional signal selected from a set of uniformly spaced directions;
an audio decoder that perceptually decodes the compressed HOA signal based on the side information to produce a decoded directional HOA signal and a decoded ambient HOA signal;
a second processor for performing order extension on the decoded ambient HOA signal to obtain a representation of the decoded ambient HOA signal; and
a synthesizer for recomposing a decoded HOA representation from the representation of the decoded ambient HOA signal and the decoded directional HOA signal.
5. The apparatus of claim 4 wherein the decoded HOA representation has an order greater than one.
6. The apparatus of claim 5 wherein the order of the decoded ambient HOA signal is less than the order of the decoded HOA representation.
7. A non-transitory computer readable medium containing instructions that when executed by a processor perform the method of claim 1 .