Nokia Technologies Oy

Nokia Corporation

Nokia Technlogies Oy

Adriana Vasilache

Lasse Juhani Laaksonen

Anssi Sakari Rämö

Anssi Ramo

Mikko Tapio Tammi

Tapani Pihlajakuja

Miikka Tapani Vilermo

Kari Juhani Jarvinen

Antti Johannes Eronen

Sujeet Shyamsundar Mate

Jussi Leppanen

Kemal Ugur

Mikko-Ville Laitinen

Pushkar Prasad Patwardhan

Jari Mathias Hagqvist

Juha Henrik Arrasvuori

Kari Juhani Järvinen

Mikko-ville Laitinen

Petri Jarske

Henri Toukomaa

James D Lynch

Anssi Rämö

Roope Olavi Jarvinen

Toni Makinen

Jussi Leppänen

Marcel Cezar Vasilache

Ioan Tabus

Miika Tapani Vilermo

There is inter alia disclosed an apparatus for spatial audio encoding configured to: determine, for two or more audio signals, a first spatial audio direction parameter and a second spatial audio direction parameter for providing spatial audio reproduction: quantize the first spatial audio direction parameter (); transform the second spatial audio direction parameter to have an opposite spatial audio direction (); determine a difference between the transformed second spatial audio direction parameter and the quantized first spatial audio direction parameter (); and quantize the difference ().

Transforming spatial audio parameters

An apparatus comprising means configured to: obtain at least one direction parameter value for a time-frequency part of at least one audio signal (); obtain at least one energy ratio for the time-frequency part (), wherein each energy ratio is associated with a respective direction parameter value; generate respective at least one modified energy ratio from the at least one energy ratio for the time-frequency part (); determine a quantization spatial resolution for encoding the at least one obtained direction parameter value based on the at least one modified energy ratio (); and encode the obtained direction parameter values based on the quantization spatial resolution ().

Spatial audio parameter encoding and associated decoding

An apparatus comprising means configured to obtain direction parameter values () associated with at least two time-frequency parts () of at least one audio signal (); and encode the obtained direction parameter values based on a codebook (), wherein the codebook comprises two or more quantization levels arranged such that a first quantization level comprises a first set of quantization values, and a second or succeeding quantization level comprises a second or further set of quantization values and preceding quantization level quantization values.

An apparatus for receiving an indicator configured to identify whether encoded spatial audio signal directional metadata parameters for time-frequency tiles of an audio frame were encoded based on a quantization resolution which is equal to or less than a determined number of bits; decode the encoded spatial audio signal directional metadata parameters for the time-frequency tiles of the audio frame based on the quantization resolution which is equal to or less than the determined number of bits when the indicator identifies as such; and when the indicator identifies that the encoded spatial audio signal directional metadata parameters were not encoded based on the quantization resolution which is equal to or less than the determined number of bits, decode a first part comprising entropy encoded spatial audio signal directional metadata parameters and decode a second part comprising fixed rate encoded spatial audio signal directional metadata parameters.

Determination of spatial audio parameter encoding and associated decoding

There is inter alia disclosed an apparatus for spatial audio encoding comprising: means for determining a first spatial audio parameter of a frequency sub band of one or more audio signals and a second spatial audio parameter of the frequency sub band of the one or more audio signals; and means for combining the first spatial audio parameter and the second spatial audio parameter to provide a combined spatial audio parameter for the frequency sub band.

Combining of spatial audio parameters

There is inter alia disclosed an apparatus for spatial audio encoding comprising: means for determining at least two of a type of spatial audio parameter for one or more audio signals, wherein a first of the type of spatial audio parameter is associated with a first group of samples in a domain of the one or more audio signals and a second of the type of spatial audio parameter is associated with a second group of samples in the domain of the one or more audio signals; and means for merging the first of the type of spatial audio parameter and the second of the type of spatial audio parameter into a merged spatial audio parameter.

Merging of spatial audio parameters

There is inter alia disclosed an apparatus for spatial audio encoding which can receive or determine for one or more audio signals (), spatial audio parameters () on a sub band basis for providing spatial audio reproduction, the spatial audio parameters can comprise a coherence value () for each sub band of a plurality of subbands () of a frame. The apparatus then determines a significance measure for the coherence values () of the plurality of sub bands of the frame and uses the significance measure to determine whether to encode () the coherence values of the plurality of sub bands of the frame.

Determination of the significance of spatial audio parameters and associated encoding

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.

A method for spatial audio signal encoding comprising: obtaining a plurality of audio direction parameters, wherein each parameter comprises an elevation value and an azimuth value and wherein each parameter has an ordered position; deriving for each of the plurality of audio direction parameters a corresponding derived audio direction parameter (SP) comprising an elevation and an azimuth value, corresponding derived audio direction parameters (SP) being arranged in a manner determined by a spatial utilization defined by the elevation values and the azimuth values of the plurality of audio direction parameters; rotating each derived audio direction parameter (SP) by the azimuth value (φ) of an audio direction parameter in the first position of the plurality of audio direction parameters and quantizing the rotation to determine for each a corresponding quantized rotated derived audio direction parameter; changing the ordered position of an audio direction parameter to a further position coinciding with a position of a rotated derived audio direction parameter when the azimuth value of the audio direction parameter is closest to the azimuth value of the further rotated derived audio direction parameter compared to the azimuth values of other rotated derived audio direction parameters, followed by determining for each of the plurality audio direction parameters a difference between each audio direction parameter and their corresponding quantized rotated derived audio direction parameter; and quantizing a difference for each of the plurality of audio direction parameters, wherein a difference quantization resolution for each of the plurality of audio direction parameters is defined based on a spatial extent of the audio direction parameters.

Quantization of spatial audio direction parameters

An apparatus comprising means configured to: generate spatial audio signal directional metadata parameters for a block of time-frequencies; generate encoded spatial audio signal directional metadata parameters () for a block of time-frequencies based on a first quantization resolution (); compare a number of bits used for the encoded spatial audio signal directional parameters () for the block of time-frequencies based on the first quantization resolution against a determined number of bits; output or store the encoded spatial audio signal directional metadata parameters for a block of time-frequencies () based on a first quantization resolution when the number of bits used for the encoded spatial audio signal directional parameters for the block of time-frequencies () based on the first quantization resolution is less than a determined number of bits (); generate encoded spatial audio signal directional metadata parameters () for the block of time-frequencies based on a second quantization resolution when the number of bits used for the encoded spatial audio signal directional parameters for the block of time-frequencies () based on the first quantization resolution is more than the determined number of bits and a difference between the determined number of bits and the number of bits used for the encoded spatial audio signal directional parameters () for the block of time-frequencies based on the first quantization resolution is less than a determined number of bits is within a determined threshold (); generate encoded spatial audio signal directional metadata parameters () for the block of time-frequencies based on a third quantization resolution when the number of bits used for the encoded spatial audio signal directional parameters () for the block of time-frequencies based on the first quantization resolution is more than the determined number of bits and the difference between the determined number of bits and the number of bits used for the encoded spatial audio signal directional parameters () for the block of time-frequencies based on the first quantization resolution is greater than the determined threshold, wherein the third quantization resolution is determined such that a number of bits used for the encoded spatial audio signal directional parameters for the block of time-frequencies based on the third quantization resolution is always equal to or less than the determined number of bits ().

An apparatus may be configured to: obtain media content, wherein the media content comprises at least one audio content; obtain priority content information, the priority content information comprising a priority identification identifying and classifying the at least one audio content; determine to at least partially reduce rendering of the at least one audio content based, at least partially, on a quota associated with the priority identification of the at least one audio content; and render the at least one audio content based, at least partially, on the priority content information and the determining.

Spatial augmentation

A method for spatial audio signal encoding comprising: obtaining, for a first frame, a plurality of audio direction parameters, wherein each parameter comprises an elevation value and an azimuth value and wherein each parameter has an ordered position; determining whether, for a preceding frame, any of the plurality of audio direction parameters was differentially encoded based on a difference between the preceding frame parameter elevation value and a further preceding frame parameter elevation value and the preceding frame parameter azimuth value and a further preceding frame parameter azimuth value; generating, for any audio direction parameter which was not differentially encoded in the considered preceding frame, a differential parameter value based on a difference between the frame parameter elevation value and a preceding frame parameter elevation value and a difference between the frame parameter azimuth value and a preceding frame parameter azimuth value; generating for each of the plurality of audio direction parameters a difference parameter value based on a difference between the audio direction parameter and a rotated derived audio direction parameter; quantizing the difference between the audio direction parameter and a rotated derived audio direction parameter and the differential parameter value; and selecting for each of the plurality of audio direction parameters, either of the quantized difference or differential parameter value.

An apparatus comprising means for: receiving values for sub-bands of a frame of an audio signal, the values comprising at least one azimuth value, at least one elevation value at least one energy ratio value and at least one spread and/or surround coherence value for each sub-band; determining a codebook for encoding at least one spread and/or surround coherence value for each sub-band based on the at least one energy ratio value and at least one azimuth value for each sub-band for a frame; discrete cosine transforming at least one vector, the at least one vector comprising the at least one spread and/or surround coherence value for a sub-band for the frame; and encoding a first number of components of the discrete cosine transformed vector based on the determined codebook.

There is disclosed inter alia an apparatus for spatial audio signal encoding comprising means for receiving for each time frequency block of a sub band of an audio frame a spatial audio parameter comprising an azimuth and an elevation; determining a first distortion measure for the audio frame by determining a first distance measure for each time frequency block and summing the first distance measure for each time frequency block; determining a second distortion measure for the audio frame by determining a second distance measure for each time frequency block and summing the second distance measure for each time frequency block, and selecting either the first quantization scheme or the second quantization scheme for quantising the elevation and the azimuth for all time frequency blocks of the sub band of the audio frame, wherein the selecting is dependent on the first and second distortion measures.

Selection of quantization schemes for spatial audio parameter encoding

An apparatus comprising means for: receiving values for sub-bands of a frame of an audio signal, the values comprising at least one azimuth value, at least one elevation value and at least one energy ratio value for each sub-band; determining an allocation of first number of bits to encode the values of the frame, wherein the first number of bits are fixed; encoding the at least one energy ratio value for a frame based on a defined allocation of a second number of bits from the first number of bits; encoding the at least one azimuth value and/or at least one elevation value of the frame based on a defined allocation of a third number of bits from the first number of bits, wherein the third number of bits is variably distributed on a sub-band-by-sub-band basis.

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Tampere, Finland

Adriana Vasilache