Abstract: A method for partitioning of input vectors for coding is presented. The method comprises obtaining of an input vector. The input vector is segmented, in a non-recursive manner, into an integer number, NSEG, of input vector segments. A representation of a respective relative energy difference between parts of the input vector on each side of each boundary between the input vector segments is determined, in a recursive manner. The input vector segments and the representations of the relative energy differences are provided for individual coding. Partitioning units and computer programs for partitioning of input vectors for coding, as well as positional encoders, are presented.

Abstract: A method for inter-channel time difference (ITD) stabilization. The method includes obtaining a candidate ITD value for an mth frame of a multi-channel audio signal, wherein the candidate ITD value for the mth frame is denoted ITDcand(m). The method also includes determining whether rmax(m) is greater than a threshold (rthr(m)), where rmax(m)=rxy(ITDcand(m)) and rxy( ) is a cross-correlation function. The method further includes, after determining that rmax(m) is not greater rthr(m): determining whether an ITD hangover criterion is met, and, if it is determined that the ITD hangover criterion is met, then selecting a previous ITD value for frame m, otherwise setting the ITD value for frame m to zero.

Abstract: A method for generating a comfort noise (CN) parameter is provided. The method includes receiving an audio input; detecting, with a Voice Activity Detector (VAD), a current inactive segment in the audio input; as a result of detecting, with the VAD, the current inactive segment in the audio input, calculating a CN parameter CNused; and providing the CN parameter CNused to a decoder. The CN parameter CNused is calculated based at least in part on the current inactive segment and a previous inactive segment.

Abstract: A method for partitioning of input vectors for coding is presented. The method comprises obtaining of an input vector. The input vector is segmented, in a non-recursive manner, into an integer number, NSEG, of input vector segments. A representation of a respective relative energy difference between parts of the input vector on each side of each boundary between the input vector segments is determined, in a recursive manner. The input vector segments and the representations of the relative energy differences are provided for individual coding. Partitioning units and computer programs for partitioning of input vectors for coding, as well as positional encoders, are presented.

Abstract: In one aspect, there is a method for rendering a spatially-heterogeneous audio element. In some embodiments, the method includes obtaining two or more audio signals representing the spatially-heterogeneous audio element, wherein a combination of the audio signals provides a spatial image of the spatially-heterogeneous audio element. The method also includes obtaining metadata associated with the spatially-heterogeneous audio element, the metadata comprising spatial extent information indicating a spatial extent of the audio element. The method further includes rendering the audio element using: i) the spatial extent information and ii) location information indicating a position (e.g. virtual position) and/or an orientation of the user relative to the audio element.

Abstract: An encoder for encoding frequency transform coefficients of a harmonic audio signal include the following elements: A peak locator configured to locate spectral peaks having magnitudes exceeding a predetermined frequency dependent threshold. A peak region encoder configured to encode peak regions including and surrounding the located peaks. A low-frequency set encoder configured to encode at least one low-frequency set of coefficients outside the peak regions and below a crossover frequency that depends on the number of bits used to encode the peak regions. A noise-floor gain encoder configured to encode a noise-floor gain of at least one high-frequency set of not yet encoded coefficients outside the peak regions.

Abstract: A method and apparatus to identify coincident microphone configurations, CC, and adapt an inter-channel time difference, ITD, search, in an encoder or a decoder is provided. The method includes for each frame m of a multi-channel audio signal: generating a cross-correlation of a channel pair of the multi-channel audio signal; determining a first ITD estimate based on the cross-correlation; determining if the multi-channel audio signal is a CC signal; and responsive to determining that the multi-channel audio signal is a CC signal, biasing the ITD search to favor ITDs close to zero to obtain a final ITD.

Abstract: A method for partitioning of input vectors for coding is presented. The method comprises obtaining of an input vector. The input vector is segmented, in a non-recursive manner, into an integer number, NSEG, of input vector segments. A representation of a respective relative energy difference between parts of the input vector on each side of each boundary between the input vector segments is determined, in a recursive manner. The input vector segments and the representations of the relative energy differences are provided for individual coding. Partitioning units and computer programs for partitioning of input vectors for coding, as well as positional encoders, are presented.

Abstract: 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.

Abstract: A method of audio rendering. The method includes receiving an audio element, wherein the audio element comprises: i) an interior representation that is valid within a spatial region, the interior representation of the audio element being in a listener-centric format and ii) information indicating the spatial region. The method further includes determining that a listener is outside the spatial region. The method further includes deriving an exterior representation of the audio element and rendering the audio element using the exterior representation of the audio element. In another aspect, a method of providing a spatially-bounded audio element is provided. The method includes providing, to a rendering node, an audio element. The audio element includes: (i) an interior representation that is valid within a spatial region, the interior representation being in a listener-centric format; and (ii) information indicating the spatial region.

Abstract: An encoder for encoding frequency transform coefficients of a harmonic audio signal include the following elements: A peak locator configured to locate spectral peaks having magnitudes exceeding a predetermined frequency dependent threshold. A peak region encoder configured to encode peak regions including and surrounding the located peaks. A low-frequency set encoder configured to encode at least one low-frequency set of coefficients outside the peak regions and below a crossover frequency that depends on the number of bits used to encode the peak regions. A noise-floor gain encoder configured to encode a noise-floor gain of at least one high-frequency set of not yet encoded coefficients outside the peak regions.

Abstract: A method for generating a final corrected head-related (HR) filter dataset, (A). The method includes obtaining a first corrected HR filter dataset, (B). Obtaining the first corrected HR filter dataset (B) includes: obtaining (s802) an initial HR filter dataset, (C); obtaining (s804) an extracted HR filter dataset, (D), extracted from the initial HR filter dataset, (C); obtaining (s806) a model, (E), of the extracted HR filter dataset, (D); generating (s808) a modelled HR filter dataset, (F), using the model, (E); selecting (s810) for correction one or more HR filters that are included in the initial HR filter dataset, (C), based on the modelled HR filter dataset, (F), and the extracted HR filter dataset, (D); and generating (s812) the first corrected HR filter dataset, (B) by correcting the selected one or more HR filters.

Abstract: A method for increasing stability of an inter-channel time difference (ICTD) parameter in parametric audio coding, wherein a multi-channel audio input signal comprising at least two channels is received. The method comprises obtaining an ICTD estimate, ICT Dest(m), for an audio frame m and a stability estimate of said ICTD estimate, and determining whether the obtained ICTD estimate, ICT Dest(m), is valid. If the ICTDest(m) is not found valid, and a determined sufficient number of valid ICTD estimates have been found in preceding frames, a hang-over time is determined using the stability estimate and a previously obtained valid ICTD parameter, ICTD(m?1), is selected as an output parameter, ICTD(m), during the hang-over time. The output parameter, ICTD(m), is set to zero if valid ICT Dest(m) is not found during the hang-over time.

Abstract: In one aspect, there is a method for rendering a spatially-heterogeneous audio element. In some embodiments, the method includes obtaining two or more audio signals representing the spatially-heterogeneous audio element, wherein a combination of the audio signals provides a spatial image of the spatially-heterogeneous audio element. The method also includes obtaining metadata associated with the spatially-heterogeneous audio element, the metadata comprising spatial extent information indicating a spatial extent of the audio element. The method further includes rendering the audio element using: i) the spatial extent information and ii) location information indicating a position (e.g. virtual position) and/or an orientation of the user relative to the audio element.

Abstract: 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.

Abstract: A method of audio rendering. The method includes receiving an audio element, wherein the audio element comprises: i) an interior representation that is valid within a spatial region, the interior representation of the audio element being in a listener-centric format and ii) information indicating the spatial region. The method further includes determining that a listener is outside the spatial region. The method further includes deriving an exterior representation of the audio element and rendering the audio element using the exterior representation of the audio element. In another aspect, a method of providing a spatially-bounded audio element is provided. The method includes providing, to a rendering node, an audio element. The audio element includes: (i) an interior representation that is valid within a spatial region, the interior representation being in a listener-centric format; and (ii) information indicating the spatial region.

Abstract: A method and a transmitting node for supporting generation of comfort noise for at least two audio channels at a receiving node. The method is performed by a transmitting node. The method comprises determining spectral characteristics of audio signals on at least two input audio channels and determining a spatial coherence between the audio signals. The spatial coherence is associated with perceptual importance measures. A compressed representation of the spatial coherence is determined per frequency band by weighting the spatial coherence within each frequency band according to the perceptual importance measures. Information about the spectral characteristics and the compressed representation of the spatial coherence per frequency band is signaled to the receiving node for enabling the generation of the comfort noise at the receiving node.

Abstract: A method for partitioning of input vectors for coding is presented. The method comprises obtaining of an input vector. The input vector is segmented, in a non-recursive manner, into an integer number, NSEG, of input vector segments. A representation of a respective relative energy difference between parts of the input vector on each side of each boundary between the input vector segments is determined, in a recursive manner. The input vector segments and the representations of the relative energy differences are provided for individual coding. Partitioning units and computer programs for partitioning of input vectors for coding, as well as positional encoders, are presented.

Abstract: A method for increasing stability of an inter-channel time difference (ICTD) parameter in parametric audio coding, wherein a multi-channel audio input signal comprising at least two channels is received. The method comprises obtaining an ICTD estimate, ICTDest(m), for an audio frame m and a stability estimate of said ICTD estimate, and determining whether the obtained ICTD estimate, ICTDest(m), is valid. If the ICTDest(m) is not found valid, and a determined sufficient number of valid ICTD estimates have been found in preceding frames, a hang-over time is determined using the stability estimate and a previously obtained valid ICTD parameter, ICTD(m?1), is selected as an output parameter, ICTD(m), during the hang-over time. The output parameter, ICTD(m), is set to zero if valid ICTDest(m) is not found during the hang-over time.

Abstract: A method for generating a comfort noise (CN) parameter is provided. The method includes receiving an audio input; detecting, with a Voice Activity Detector (VAD), a current inactive segment in the audio input; as a result of detecting, with the VAD, the current inactive segment in the audio input, calculating a CN parameter CNused; and providing the CN parameter CNused to a decoder. The CN parameter CNused is calculated based at least in part on the current inactive segment and a previous inactive segment.