An audio metadata providing apparatus and method and a multichannel audio data playback apparatus and method to support a dynamic format conversion are provided. Dynamic format conversion information may include information about a plurality of format conversion schemes that are used to convert a first format set by an author of multichannel audio data into a second format that is based on a playback environment of the multichannel audio data and that are each set for corresponding playback periods of the multichannel audio data. The audio metadata providing apparatus may provide audio metadata including the dynamic format conversion information. The multichannel audio data playback apparatus may identify the dynamic format conversion information from the audio metadata, may convert the first format of the multichannel audio data into the second format based on the identified dynamic format conversion information, and may play back the multichannel audio data in the second format.

An audio metadata providing apparatus and method and a multichannel audio data playback apparatus and method to support a dynamic format conversion are provided. Dynamic format conversion information may include information about a plurality of format conversion schemes that are used to convert a first format set by an author of multichannel audio data into a second format that is based on a playback environment of the multichannel audio data and that are each set for corresponding playback periods of the multichannel audio data. The audio metadata providing apparatus may provide audio metadata including the dynamic format conversion information. The multichannel audio data playback apparatus may identify the dynamic format conversion information from the audio metadata, may convert the first format of the multichannel audio data into the second format based on the identified dynamic format conversion information, and may play back the multichannel audio data in the second format.

The present disclosure provides methods, devices and computer program products which provide less complex and more flexible control of the introduced decorrelation in an audio coding system. According to the disclosure, this is achieved by calculating and using two weighting factors, one for an approximated audio object and one for a decorrelated audio object, for introduction of decorrelation of audio objects in the audio coding system.

The present disclosure provides methods, devices and computer program products which provide less complex and more flexible control of the introduced decorrelation in an audio coding system. According to the disclosure, this is achieved by calculating and using two weighting factors, one for an approximated audio object and one for a decorrelated audio object, for introduction of decorrelation of audio objects in the audio coding system.

The present technology relates to signal processing device and method that make it possible to reproduce sound more effectively. A signal processing device includes a rotation operation unit that rotates a head-related transfer function in a spherical harmonic domain by an operation on the basis of a rotation matrix corresponding to rotation of a head of a listener, the operation in which an order of the rotation matrix is limited, and a synthesis unit that synthesizes the head-related transfer function after rotation obtained by the operation and a sound signal of the spherical harmonic domain to generate a headphone drive signal. The present technology is applicable to an audio processor.

The present technology relates to signal processing device and method that make it possible to reproduce sound more effectively. A signal processing device includes a rotation operation unit that rotates a head-related transfer function in a spherical harmonic domain by an operation on the basis of a rotation matrix corresponding to rotation of a head of a listener, the operation in which an order of the rotation matrix is limited, and a synthesis unit that synthesizes the head-related transfer function after rotation obtained by the operation and a sound signal of the spherical harmonic domain to generate a headphone drive signal. The present technology is applicable to an audio processor.

Sound scenes in 3D can be synthesized or captured as a natural sound field. For decoding, a decode matrix is required that is specific for a given loudspeaker setup and is generated using the known loudspeaker positions. However, some source directions are attenuated for 2D loudspeaker setups like e.g. 5.1 surround. An improved method for decoding an encoded audio signal in soundfield format for L loudspeakers at known positions comprises steps of adding (10) a position of at least one virtual loudspeaker to the positions of the L loudspeakers, generating (11) a 3D decode matrix (D′), wherein the positions (Formula I) of the L loudspeakers and the at least one virtual position (Formula II) are used, downmixing (12) the 3D decode matrix (D′), and decoding (14) the encoded audio signal (i14) using the downscaled 3D decode matrix (Formula III). As a result, a plurality of decoded loudspeaker signals (q14) is obtained.

Sound scenes in 3D can be synthesized or captured as a natural sound field. For decoding, a decode matrix is required that is specific for a given loudspeaker setup and is generated using the known loudspeaker positions. However, some source directions are attenuated for 2D loudspeaker setups like e.g. 5.1 surround. An improved method for decoding an encoded audio signal in soundfield format for L loudspeakers at known positions comprises steps of adding (10) a position of at least one virtual loudspeaker to the positions of the L loudspeakers, generating (11) a 3D decode matrix (D′), wherein the positions (Formula I) of the L loudspeakers and the at least one virtual position (Formula II) are used, downmixing (12) the 3D decode matrix (D′), and decoding (14) the encoded audio signal (i14) using the downscaled 3D decode matrix (Formula III). As a result, a plurality of decoded loudspeaker signals (q14) is obtained.

A system and method for acoustically reproducing Q electrical audio signals and establishing N sound zones is provided. Reception sound signals occur that provide an individual pattern of the reproduced and transmitted Q electrical audio signals. The method includes processing the Q electrical audio signals to provide K processed electrical audio signals and converting the K processed electrical audio signals into corresponding K acoustic audio signals with K groups of loudspeakers that are arranged at positions separate from each other and within or adjacent to the N sound zones. The method further includes monitoring a position of a listener's head relative to a reference listening position. Each of the K acoustic audio signals is transferred according to a transfer matrix from each of the K groups of loudspeakers to each of the N sound zones to contribute to the corresponding reception sound signals.

The present technology relates to an audio processing apparatus capable of downmixing 7.1-ch audio data to 2-ch audio data. A coefficient for downmixing 7.1-ch audio data to 2-ch audio data is set from a coefficient for downmixing 7.1-ch audio data to 5.1-ch audio data specified by a Moving Picture Experts Group 4 (MPEG4) audio standard and a coefficient for downmixing 5.1-ch audio data to 2-ch audio data specified by the standard, and stored in a 2-ch downmixing coefficient unit 22. A 2-ch downmixing unit 21 downmixes 7.1-ch audio data to 2-ch audio data using a coefficient stored in the 2-ch downmixing coefficient unit 22. The present technology can be applied to an audio processing apparatus.