Coding higher-order ambisonic coefficients during multiple transitions

A method of decoding a bitstream representative of higher-order ambisonic (HOA) audio data, the method comprising:

• obtaining, by one or more processors, a multi-transition indication of whether an ambient HOA coefficient is in transition during a same frame of the bitstream as a foreground audio signal is in transition;
• and
• obtaining, by the one or more processors, a vector that describes a spatial characteristic of a corresponding foreground audio signal based on the multi-transition indication, both the vector defined in a spherical harmonic domain;
• rendering, by the one or more processors and based on the vector, one or more speaker feeds;
• and
• outputting, by the one or more processors, the one or more speaker feeds to one or more speakers.

A non-transitory computer-readable storage medium having stored thereon instructions that, when executed, cause one or more processors to:

• obtain a multi-transition indication of whether an ambient HOA coefficient is in transition during a same frame of a bitstream as a foreground audio signal is in transition;
• and
• obtain a vector that describes a spatial characteristic of a corresponding foreground audio signal based on the multi-transition indication, the vector defined in a spherical harmonic domain;
• render, based on the vector, one or more speaker feeds;
• and
• output the one or more speaker feeds to one or more speakers.

A device for decoding a bitstream representative of higher-order ambisonic (HOA) audio data, the device comprising:

• means for obtaining a multi-transition indication of whether an ambient HOA coefficient is in transition during a same frame of the bitstream as a foreground audio signal is in transition;
• and
• means for obtaining a vector that describes a spatial characteristic of a corresponding foreground audio signal based on the multi-transition indication, the vector defined in a spherical harmonic domain;
• means for rendering, based on the vector, one or more loudspeaker feeds;
• and
• means for outputting the one or more speaker feeds to one or more loudspeakers.

A device configured to encode a bitstream representative of higher-order ambisonic (HOA) audio data, the device comprising:

• one or more processors configured to:
• obtain, based on audio signals captured by a microphone, the HOA audio data;
• decompose at least a portion of the HOA audio data to obtain a foreground audio signal and a vector representative of a spatial component of the foreground audio signal, the vector defined in a spherical harmonic domain;
• obtain a multi-transition indication of whether an ambient HOA coefficient is in transition during a same frame of the bitstream as the foreground audio signal is in transition;
• obtain elements of the vector based on the multi-transition indication;
• and
• specify, in the bitstream, the obtained elements of the vector;
• and
• a memory coupled to the one or more processors, and configured to store the vector.

A method of encoding a bitstream representative of higher-order ambisonic (HOA) audio data, the method comprising:

• obtaining, by one or more processors and based on audio signals captured by a microphone, the HOA audio data;
• decomposing, by the one or more processors, at least a portion of the HOA audio data to obtain a foreground audio signal and a vector representative of a spatial component of the foreground audio signal, the vector defined in a spherical harmonic domain;
• obtaining, by the one or more processors, a multi-transition indication of whether an ambient HOA coefficient is in transition during a same frame of the bitstream as the foreground audio signal is in transition;
• obtaining, by the one or more processors, elements of the vector based on the multi-transition indication;
• and
• specifying, by the one or more processors and in the bitstream, the obtained elements of the vector.

A non-transitory computer-readable storage medium having stored thereon instructions that, when executed, cause one or more processors to:

• obtain, based on audio signals captured by a microphone, the HOA audio data;
• decompose at least a portion of the HOA audio data to obtain a foreground audio signal and a vector representative of a spatial component of the foreground audio signal, the vector defined in a spherical harmonic domain;
• obtain a multi-transition indication of whether an ambient HOA coefficient is in transition during a same frame of a bitstream as the foreground audio signal is in transition;
• obtain elements of the vector based on the multi-transition indication;
• and
• specify, in the bitstream, the obtained elements of the vector.

A device for encoding a bitstream representative of higher-order ambisonic (HOA) audio data, the device comprising:

• means for obtaining, based on audio signals captured by a microphone, the HOA audio data;
• means for decomposing at least a portion of the HOA audio data to obtain a foreground audio signal and a vector representative of a spatial component of the foreground audio signal, the vector defined in a spherical harmonic domain;
• means for obtaining a multi-transition indication of whether an ambient HOA coefficient is in transition during a same frame of the bitstream as the foreground audio signal is in transition;
• means for obtaining elements of the vector based on the multi-transition indication;
• and
• means for specifying, in the bitstream, the obtained elements of the vector.