A method comprising: obtaining a first audio direction parameter value for each sub-band of a sub-frame of a frame of an audio signal; obtaining a second audio direction parameter value for the sub-frame of the frame of the audio signal for one or more audio objects associated with said audio signal; and determining a bit-efficient encoding for each first audio direction parameter value of the sub-frame based on a similarity between the first audio direction parameter value for each sub-band and the second audio direction parameter values for the one or more audio objects.

In some examples, an audio control system can include a first set of resources, a second set of resources and a controller. The first set of resources can generate a frequency energy band representation of a multi-channel source audio input. Additionally, the second set of resources can determine at least a value representing a strength of correlation between multiple channels of the multi-channel source audio input. Moreover, the audio output controller can determine a set of control parameters for tuning sound creation from an audio signal generator to reflect a set of spatial characteristics of the source audio input, based on the frequency energy band representation and the first value.

An audio signal processing method and apparatus for adaptively adjusting a decorrelator. The method comprises obtaining a control parameter and calculating mean and variation of the control parameter. Ratio of the variation and mean of the control parameter is calculated, and a decorrelation parameter is calculated based on the said ratio. The decorrelation parameter is then provided to a decorrelator.

Audiovisual presentations, such as film recordings, may have been originally created having an audio soundtrack with multiple audio tracks mixed for a surround sound system that includes a set of speakers physically surrounding a user. The present disclosure presents systems and methods to remix these soundtracks into 3D audio that when presented to the ears of a user can be perceived as a virtual surround sound system that mimics the physical system. What is more, the disclosed systems and methods can enhance the virtual surround sound system by adjusting virtual speakers of the virtual surround sound system according to video content of the audiovisual presentation. Further enhancement may be possible by adjusting the virtual speakers of the virtual surround sound system according to a sensed position of a user.

Embodiments are described for an adaptive audio system that processes audio data comprising a number of independent monophonic audio streams. One or more of the streams has associated with it metadata that specifies whether the stream is a channel-based or object-based stream. Channel-based streams have rendering information encoded by means of channel name; and the object-based streams have location information encoded through location expressions encoded in the associated metadata. A codec packages the independent audio streams into a single serial bitstream that contains all of the audio data. This configuration allows for the sound to be rendered according to an allocentric frame of reference, in which the rendering location of a sound is based on the characteristics of the playback environment (e.g., room size, shape, etc.) to correspond to the mixer's intent. The object position metadata contains the appropriate allocentric frame of reference information required to play the sound correctly using the available speaker positions in a room that is set up to play the adaptive audio content.

The following coding scenario is addressed: A number of audio source signals need to be transmitted or stored for the purpose of mixing wave field synthesis, multi-channel surround, or stereo signals after decoding the source signals. The proposed technique offers significant coding gain when jointly coding the source signals, compared to separately coding them, even when no redundancy is present between the source signals. This is possible by considering statistical properties of the source signals, the properties of mixing techniques, and spatial hearing. The sum of the source signals is transmitted plus the statistical properties of the source signals, which mostly determine the perceptually important spatial cues of the final mixed audio channels. Source signals are recovered at the receiver such that their statistical properties approximate the corresponding properties of the original source signals. Subjective evaluations indicate that high audio quality is achieved by the proposed scheme.

An audio decoder for providing at least four bandwidth-extended channel signals on the basis of an encoded representation provides first and second downmix signals on the basis of a jointly encoded representation of the first and second downmix signals using a multi-channel decoding and provides at least first and second audio channel signals on the basis of the first downmix signal using a multi-channel decoding, and provides at least third and fourth audio channel signals on the basis of the second downmix signal using a multi-channel decoding. It performs a multi-channel bandwidth extension on the basis of the first and third audio channel signals, to obtain first and third bandwidth-extended channel signals, and performs a multi-channel bandwidth extension on the basis of the second and fourth audio channel signals, to obtain second and fourth bandwidth extended channel signals. An audio encoder uses a related concept.

The present document relates to audio coding systems. In particular, the present document relates to efficient methods and systems for parametric multi-channel audio coding. An audio encoding system configured to generate a bitstream indicative of a downmix signal and spatial metadata for generating a multi-channel upmix signal from the downmix signal is described. The system comprises a downmix processing unit configured to generate the downmix signal from a multi-channel input signal; wherein the downmix signal comprises m channels and wherein the multi-channel input signal comprises n channels; n, m being integers with m<n. Furthermore, the system comprises a parameter processing unit configured to determine the spatial metadata from the multi-channel input signal. In addition, the system comprises a configuration unit configured to determine one or more control settings for the parameter processing unit based on one or more external settings; wherein the one or more external settings comprise a target data-rate for the bitstream and wherein the one or more control settings comprise a maximum data-rate for the spatial metadata.

A method including: obtaining at least two audio signals for reproduction, each of the at least two audio signals associated with a respective one of at least two reproduction locations within an audio reproduction space; obtaining within the audio reproduction space at least two zones; obtaining at least one location for a user's position within the audio reproduction space, the at least one location being relative to at least one of the at least two zones and the at least two reproduction locations; and processing the at least two audio signals based on the obtained at least one location for the user's position within the audio reproduction space to generate at least one output audio signal, the at least one output audio signal is reproduced from at least one of the at least two reproduction locations.

Disclosed is a device for processing an audio signal, which renders an audio signal. The device for processing an audio signal includes a processor. The processor receives metadata including an audio signal and first element reference distance information and renders a first element signal on the basis of the first element reference distance information, wherein the first element reference distance information indicates the reference distance of an element signal. The audio signal is capable of including a second element signal which may be simultaneously rendered with the first element signal, and the metadata is capable of including second element distance information indicating the distance of the second element signal. The number of bits required for representing the first element reference distance information is smaller than the number of bits required for representing the second element distance information.