Rotation of sound components for orientation-dependent coding schemes

A method for decoding scene-based audio, comprising:

• receiving, by a decoder, information representing rotated audio components of a frame of an audio signal and a parameterization of rotation parameters used to generate the rotated audio components, wherein the rotated audio components were rotated, by an encoder, from an original orientation, and wherein the rotated audio components have been rotated to a rotated orientation that aligns with a direction preference of a coding scheme used by the encoder and the decoder, wherein the direction preference of the coding scheme corresponds to the direction of a direction dependent component in an audio signal that is waveform encoded;
• decoding the received information based at least in part on the coding scheme;
• reversing a rotation of the audio components based at least in part on the parameterization of the rotation parameters to recover the original orientation,
• wherein reversing the rotation of the audio components comprises rotating the audio components around a first axis by a first rotation amount and around a second axis by a second rotation amount, and wherein the first rotation amount and the second rotation amount are indicated in the parameterization of the rotation parameters;
• and
• rendering the audio components at least partly subject to the recovered original orientation.

A method for encoding scene-based audio, comprising:

• determining, by an encoder, a spatial direction of a dominant sound component in a frame of an input audio signal;
• determining, by the encoder, rotation parameters based on the determined spatial direction and a direction preference of a coding scheme to be used to encode the input audio signal, wherein the direction preference of the coding scheme corresponds to the direction of a direction dependent component in an audio signal that is waveform encoded;
• modifying the direction preference of the coding scheme to generate an adapted coding scheme, wherein the modified direction preference is determined based on the rotation parameters or the determined spatial direction of the dominant sound component such that the spatial direction of the dominant sound component is aligned with the modified direction preference of the adapted coding scheme,
• wherein modifying the direction preference of the coding scheme comprises:
• determining a first rotation amount and a second rotation amount for the direction preference of the coding scheme based on the spatial direction of the dominant sound component and the direction preference of the coding scheme;
• and
• rotating the direction preference of the coding scheme around a first axis by the first rotation amount and around a second axis by said second rotation amount such that the spatial direction of the dominant sound component, after rotation, is aligned with the modified direction preference of the adapted coding scheme;
• and
• encoding sound components of the frame of the input audio signal using the adapted coding scheme in connection with an indication of the modified direction preference.

A method for decoding scene-based audio, comprising:

• receiving, by a decoder, information representing audio components of a frame of an audio signal and an indication of an adaptation of a coding scheme by an encoder to encode the audio components, wherein the coding scheme was adapted by the encoder such that a spatial direction of a dominant sound component of the audio components and a direction preference of the coding scheme are aligned, wherein the direction preference of the coding scheme corresponds to the direction of a direction dependent component in an audio signal that is waveform encoded;
• adapting the decoder based on the indication of the adaptation of the coding scheme, wherein adapting the decoder comprises rotating the direction preference of the coding scheme around a first axis by a first rotation amount and around a second axis by a second rotation amount, and wherein the first rotation amount and the second rotation amount are indicated in the indication of the adaptation of the coding scheme;
• and
• decoding the audio components of the frame of the audio signal using the adapted decoder.