Abstract: A method for parametric encoding of a multi-channel digital audio signal. The method includes encoding a mono signal from channel-reduction processing applied to the multi-channel signal and encoding spatialisation information of the multi-channel signal. The channel-reduction processing includes the following steps, implemented for each spectral unit of the multi-channel signal: extracting at least one indicator characterizing the channels of the multi-channel digital audio signal; selecting, from a set of channel-reduction processing modes, a channel-reduction processing mode in accordance with the value of the at least one indicator characterizing the channels of the multi-channel audio signal. Also provides are a corresponding encoding device and a processing method which includes the channel-reduction processing.

Abstract: 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.

Abstract: An apparatus for processing an encoded audio signal having a plurality of downmix signals associated with a plurality of input audio objects and object parameters E. The apparatus includes a grouper configured to group the downmix signals into groups of downmix signals associated with a set of input audio objects. The apparatus includes a processor configured to perform at least one processing step individually on the object parameters Ek of each set of input audio objects in order to provide group results. Further, there is a combiner configured to combine the group results or processed group results in order to provide a decoded audio signal. The grouper is configured to group the downmix signals so that each input audio object belongs to just one set of input audio objects. The invention also refers to a corresponding method.

Abstract: An encoding method for a multi-channel audio signal, an encoding apparatus for performing the encoding method, and a decoding method for a multi-channel audio signal and a decoding apparatus for performing the decoding method are disclosed. A method and apparatus of bypassing an MPEG Surround (MPS) standard operation and using an arbitrary tree when a number of audio signals of N channels exceeds a channel number defined in an MPS standard, is disclosed.

Abstract: A method and system are implemented in a stereo sound signal encoding system for time domain down mixing right and left channels of an input stereo sound signal into primary and secondary channels. Correlation of the primary and secondary channels of previous frames is determined, and an out-of-phase condition of the left and right channels is detected based on the correlation of the primary and secondary channels of the previous frames. The left and right channels are time domain down mixed, as a function of the detection, to produce the primary and secondary channels using a factor ?, wherein the factor ? determines respective contributions of the left and right channels upon production of the primary and secondary channels.

Abstract: A multi-channel decoder for generating a binaural signal from a downmix signal using upmix rule information on an energy-error introducing upmix rule for calculating a gain factor based on the upmix rule information and characteristics of head related transfer function based filters corresponding to upmix channels. The one or more gain factors are used by a filter processor for filtering the downmix signal so that an energy corrected binaural signal having a left binaural channel and a right binaural channel is obtained.

Abstract: A method is described which decodes a downmix matrix for mapping a plurality of input channels of audio content to a plurality of output channels, the input and output channels being associated with respective speakers at predetermined positions relative to a listener position, wherein the downmix matrix is encoded by exploiting the symmetry of speaker pairs of the plurality of input channels and the symmetry of speaker pairs of the plurality of output channels. Encoded information representing the encoded downmix matrix is received and decoded for obtaining the decoded downmix matrix.

Abstract: Example embodiments disclosed herein relate to signal processing. A method for decomposing a plurality of audio signals from at least two different channels is disclosed. The method obtains a set of components that are weakly correlated wherein the set of components generated based on the plurality of audio signals. The method extract a feature from the set of components and determining determines a set of gains associated with the set of components at least in part based on the extracted feature. Each of the gains indicate a proportion of a diffuse part in the associated component and decompose the plurality of audio signals by applying the set of gains to the set of components. Corresponding system and computer program product are also disclosed.

Abstract: A method including, during a free-viewpoint rendering to a user, where the free-viewpoint rendering comprises rendering of an audio object, and during relative movement between a location of the user and the audio object in the free-viewpoint rendering, detecting a locational conflict abnormality between the audio object and the location of the user; and based upon the detecting of the locational conflict abnormality, changing the rendering of the audio object, where the changing is based upon at least one predetermined abnormality modification parameter.

Abstract: Decoding of Ambisonics representations for a stereo loudspeaker setup is known for first-order Ambisonics audio signals. But such first-order Ambisonics approaches have either high negative side lobes or poor localization in the frontal region. The invention deals with the processing for stereo decoders for higher-order Ambisonics HOA. The desired panning functions can be derived from a panning law for placement of virtual sources between the loudspeakers. For each loudspeaker a desired panning function for all possible input directions at sampling points is defined. The panning functions are approximated by circular harmonic functions, and with increasing Ambisonics order the desired panning functions are matched with decreasing error. For the frontal region between the loudspeakers, a panning law like the tangent law or vector base amplitude panning (VBAP) are used. For the rear directions panning functions with a slight attenuation of sounds from these directions are defined.

Abstract: One embodiment provides for a compute apparatus to perform machine learning operations, the apparatus comprising a decode unit to decode a single instruction into a decoded instruction that specifies multiple operands including an input value and a quantized weight value associated with a neural network and an arithmetic logic unit including a barrel shifter, an adder, and an accumulator register, wherein to execute the decoded instruction, the barrel shifter is to shift the input value by the quantized weight value to generate a shifted input value and the adder is to add the shifted input value to a value stored in the accumulator register and update the value stored in the accumulator register.

Abstract: In general, techniques are described for inserting audio channels into descriptions of soundfields. A device comprising a processor may be configured to perform the techniques. The processor may be configured to obtain an audio channel separate from a higher-order ambisonic representation of a soundfield. The processor may further be configured to insert the audio channel at a spatial location within the soundfield such that the audio channel is able to be extracted from the soundfield.

Abstract: An example device includes a memory device, and a processor coupled to the memory device. The memory is configured to store a plurality of representations of a soundfield. The processor is configured to track a steering angle provided by one or more angles associated with the device, and to select, based on the steering angle, a representation of the soundfield from the plurality of representations stored to the memory device.

Abstract: A schematic block diagram of an audio encoder for encoding a multichannel audio signal is shown. The audio encoder includes a linear prediction domain encoder, a frequency domain encoder, and a controller for switching between the linear prediction domain encoder and the frequency domain encoder. The controller is configured such that a portion of the multichannel signal is represented either by an encoded frame of the linear prediction domain encoder or by an encoded frame of the frequency domain encoder. The linear prediction domain encoder includes a downmixer for downmixing the multichannel signal to obtain a downmixed signal. The linear prediction domain encoder further includes a linear prediction domain core encoder for encoding the downmix signal and furthermore, the linear prediction domain encoder includes a first joint multichannel encoder for generating first multichannel information from the multichannel signal.

Abstract: An apparatus for downmixing three or more audio input channels to obtain two or more audio output channels is provided. The apparatus includes a receiving interface for receiving the three or more audio input channels and for receiving side information. Moreover, the apparatus includes a downmixer for downmixing the three or more audio input channels depending on the side information to obtain the two or more audio output channels. The number of the audio output channels is smaller than the number of the audio input channels. The side information indicates a characteristic of at least one of the three or more audio input channels, or a characteristic of one or more sound waves recorded within the one or more audio input channels, or a characteristic of one or more sound sources which emitted one or more sound waves recorded within the one or more audio input channels.

Abstract: Currently there is no simple and satisfying way to create 3D audio from existing 2D content. The conversion from 2D to 3D sound should spatially redistribute the sound from existing channels. From a multi-channel 2D audio input signal (x(k)(t)) a 3D sound representation is generated which includes an HOA representation Formula (I) and channel object signals Formula (II) scaled from channels of the 2D audio input signal. Additional signals Formula (III) placed in the 3D space are generated by scaling (21, 222; 41, 422; Formula (IV)) channels from the 2D audio input signal and by decorrelating (24, 25; 44, 45, 451; Formula (V)) a scaled version of a mix of channels from the 2D audio input signal, whereby spatial positions for the additional signals are predetermined. The additional signals Formula (III) are converted (27; 47) to a HOA representation Formula (I).

Abstract: A stereo sound encoding method and system for encoding left and right channels of a stereo sound signal, down mix the left and right channels of the stereo sound signal to produce primary and secondary channels, encode the primary channel, and encode the secondary channel. Encoding the secondary channel comprises analyzing coherence between coding parameters calculated during the secondary channel encoding and coding parameters calculated during the primary channel encoding to decide if the coding parameters calculated during the primary channel encoding are sufficiently close to the coding parameters calculated during the secondary channel encoding to be re-used during the secondary channel encoding.

Abstract: A stereo sound signal encoding method and system for time domain down mixing right and left channels of an input stereo sound signal into primary and secondary channels, determine normalised correlations of the left channel and right channel in relation to a monophonic signal version of the sound. A long-term correlation difference is determined on the basis of the normalised correlation of the left channel and the normalised correlation of the right channel. The long-term correlation difference is converted into a factor ?, and the left and right channels are mixed to produce the primary and secondary channels using the factor ?, wherein the factor ? determines respective contributions of the left and right channels upon production of the primary and secondary channels.

Abstract: A data recovery circuit provides compensation for baseline wander exhibited by a data signal. An adaptive equalizer generates a recovered data signal from a data input. A level shifter and low-pass filter provide a compensation signal as a function of the recovered data signal. An adaptation engine adjusts the level of the compensation signal to compensate for baseline wander. The adaptive equalizer generates the recovered data signal as a function of the data input and the compensation signal, thereby providing accurate recovery of the data signal.

Abstract: A method for encoding multi-channel HOA audio signals for noise reduction comprises steps of decorrelating the channels using an inverse adaptive DSHT, the inverse adaptive DSHT comprising a rotation operation and an inverse DSHT, with the rotation operation rotating the spatial sampling grid of the iDSHT, perceptually encoding each of the decorrelated channels, encoding rotation information, the rotation information comprising parameters defining said rotation operation, and transmitting or storing the perceptually encoded audio channels and the encoded rotation information.

Abstract: Techniques of rendering high-order ambisonics (HOAs) involve adjusting the weights of a spherical harmonic (SH) expansion of a sound field based on weights of a SH expansion of a direction emphasis function that multiplies a monopole density that, when its product with a Green's function is integrated over the unit sphere, produces the sound field. An advantage of the improved techniques lies in the ability to better reproduce directionality of a given sound field in a computationally manner, whether the sound field is a temporal function or a time-frequency function.

Abstract: Described herein is a method (30) of rendering an audio signal (17) for playback in an audio environment (27) defined by a target loudspeaker system (23), the audio signal (17) including audio data relating to an audio object and associated position data indicative of an object position. Method (30) includes the initial step (31) of receiving the audio signal (17). At step (32) loudspeaker layout data for the target loudspeaker system (23) is received. At step (33) control data is received that is indicative of a position modification to be applied to the audio object in the audio environment (27). At step (38) in response to the position data, loudspeaker layout data and control data, rendering modification data is generated. Finally, at step (39) the audio signal (17) is rendered with the rendering modification data to output the audio signal (17) with the audio object at a modified object position that is between loudspeakers within the audio environment (27).

Abstract: Improved tools for authoring and rendering audio reproduction data are provided. Some such authoring tools allow audio reproduction data to be generalized for a wide variety of reproduction environments. Audio reproduction data may be authored by creating metadata for audio objects. The metadata may be created with reference to speaker zones. During the rendering process, the audio reproduction data may be reproduced according to the reproduction speaker layout of a particular reproduction environment.

Abstract: When compressing an HOA data frame representation, a gain control (15, 151) is applied for each channel signal before it is perceptually encoded (16). The gain values are transferred in a differential manner as side information. However, for starting decoding of such streamed compressed HOA data frame representation absolute gain values are required, which should be coded with a minimum number of bits. For determining such lowest integer number (?e) of bits the HOA data frame representation (C(k)) is rendered in spatial domain to virtual loudspeaker signals lying on a unit sphere, followed by normalization of the HOA data frame representation (C(k)). Then the lowest integer number of bits is set to: (AA).

Abstract: Provided are an encoding method of a multichannel signal, an encoding apparatus to perform the encoding method, a multichannel signal processing method, and a decoding apparatus to perform the decoding method. The decoding method may include identifying an N/2-channel downmix signal derived from an N-channel input signal; and generating an N-channel output signal from the identified N/2-channel downmix signal using a plurality of one-to-two (OTT) boxes. If a low frequency effect (LFE) channel is absent in the output signal, the number of OTT boxes may be equal to N/2 where N/2 denotes the number of channels of the downmix signal.

Abstract: A device for processing audio signals includes an interchannel temporal mismatch analyzer, an interchannel phase difference (IPD) mode selector and an IPD estimator. The interchannel temporal mismatch analyzer is configured to determine an interchannel temporal mismatch value indicative of a temporal misalignment between a first audio signal and a second audio signal. The IPD mode selector is configured to select an IPD mode based on at least the interchannel temporal mismatch value. The IPD estimator is configured to determine IPD values based on the first audio signal and the second audio signal. The IPD values have a resolution corresponding to the selected IPD mode.

Abstract: Encoding of Higher Order Ambisonics (HOA) signals commonly results in high data rates. For data rate reduction, a method (100) for encoding direction information for frames of an input HOA signal comprises determining (s101) active candidate directions (MDIR(k)) among predefined global directions having global direction indices, dividing (s102) the input HOA signal into frequency subbands (f1 . . .

Abstract: A decoder for generating a frequency enhanced audio signal, includes: a feature extractor for extracting a feature from a core signal; a side information extractor for extracting a selection side information associated with the core signal; a parameter generator for generating a parametric representation for estimating a spectral range of the frequency enhanced audio signal not defined by the core signal, wherein the parameter generator is configured to provide a number of parametric representation alternatives in response to the feature, and wherein the parameter generator is configured to select one of the parametric representation alternatives as the parametric representation in response to the selection side information; and a signal estimator for estimating the frequency enhanced audio signal using the parametric representation selected.

Abstract: A method of processing sound in a hearing aid (100, 300, 400) comprises separating the input transducer signal into a periodic and aperiodic signal for further processing in the hearing aid (100, 300, 400). The invention also provides a hearing aid (100, 300, 400) adapted for carrying out such a method of sound processing.

Abstract: A multi-channel decoder for generating a binaural signal from a downmix signal using upmix rule information on an energy-error introducing upmix rule for calculating a gain factor based on the upmix rule information and characteristics of head related transfer function based filters corresponding to upmix channels. The one or more gain factors are used by a filter processor for filtering the downmix signal so that an energy corrected binaural signal having a left binaural channel and a right binaural channel is obtained.

Abstract: A camera system capable of capturing images of an event in a dynamic environment includes two microphones configured to capture stereo audio of the event. The microphones are on orthogonal surfaces of the camera system. Because the microphones are on orthogonal surfaces of the camera system, the camera body can impact the spatial response of the two recorded audio channels differently, leading to degraded stereo recreation if standard beam forming techniques are used. The camera system includes tuned beam forming techniques to generate multi-channel audio that more accurately recreates the stereo audio by compensating for the shape of the camera system and the orientation of microphones on the camera system. The tuned beam forming techniques include optimizing a set of beam forming parameters, as a function of frequency, based on the true spatial response of the recorded audio signals.

Abstract: A device includes a processor, a memory, and a combiner. The processor is configured to receive a first combined frame and a second combined frame corresponding to a multi-channel audio signal. The memory is configured to store first lookahead portion data of the first combined frame. The first lookahead portion data is received from the processor. The combiner is configured to generate a frame at a multi-channel encoder. The frame includes a subset of samples of the first lookahead portion data, one or more samples of updated sample data corresponding to the first combined frame, and a group of samples of second combined frame data corresponding to the second combined frame.

Abstract: A multi-channel decoder for generating a binaural signal from a downmix signal using upmix rule information on an energy-error introducing upmix rule for calculating a gain factor based on the upmix rule information and characteristics of head related transfer function based filters corresponding to upmix channels. The one or more gain factors are used by a filter processor for filtering the downmix signal so that an energy corrected binaural signal having a left binaural channel and a right binaural channel is obtained.

Abstract: A multi-channel decoder for generating a binaural signal from a downmix signal using upmix rule information on an energy-error introducing upmix rule for calculating a gain factor based on the upmix rule information and characteristics of head related transfer function based filters corresponding to upmix channels. The one or more gain factors are used by a filter processor for filtering the downmix signal so that an energy corrected binaural signal having a left binaural channel and a right binaural channel is obtained.

Abstract: A multi-channel decoder for generating a binaural signal from a downmix signal using upmix rule information on an energy-error introducing upmix rule for calculating a gain factor based on the upmix rule information and characteristics of head related transfer function based filters corresponding to upmix channels. The one or more gain factors are used by a filter processor for filtering the downmix signal so that an energy corrected binaural signal having a left binaural channel and a right binaural channel is obtained.

Abstract: A multi-channel decoder for generating a binaural signal from a downmix signal using upmix rule information on an energy-error introducing upmix rule for calculating a gain factor based on the upmix rule information and characteristics of head related transfer function based filters corresponding to upmix channels. The one or more gain factors are used by a filter processor for filtering the downmix signal so that an energy corrected binaural signal having a left binaural channel and a right binaural channel is obtained.

Abstract: In general, techniques are described by which to perform bitrate allocation with respect to higher order ambisonic (HOA) audio data. A device comprising a memory and a processor may be configured to perform various aspects of the bitrate allocation techniques. The memory may be configured to store a spatially compressed version of the HOA audio data. The processor may be coupled to the memory, and configured to perform bitrate allocation, based on an analysis of transport channels representative of the spatially compressed version of the HOA audio data, and prior to performing gain control with respect to the transport channels or after performing inverse gain control with respect to the transport channels, to allocate a number of bits to each of the transport channels. The processor may also be configured to generate a bitstream that specifies each of the transport channels using the respective allocated number of bits.

Abstract: A decoding device includes: a separating unit separating first encoded data, a spectrum including a low-band spectrum of audio signals having been encoded, and second encoded data, a high-band spectrum of a higher band having been encoded, based on the first encoded data; a first decoding unit decoding the first encoded data and generating a first decoded spectrum; a first amplitude normalizer dividing amplitude of the first decoded spectrum into sub-bands, normalizing the spectrum of each sub-band by the largest amplitude of the first decoded spectrum within each sub-band, and generating a normalized spectrum; an addition unit adding noise spectrum to the normalized spectrum and generating a noise-added normalized spectrum; a second decoding unit decoding the second encoded data using the noise-added normalized spectrum, and generating a second noise-added spectrum; and a converter performing time-frequency conversion regarding a spectrum coupled based on the first decoded spectrum and second noise-added spe

Abstract: A decoder for generating a frequency enhanced audio signal, includes: a feature extractor for extracting a feature from a core signal; a side information extractor for extracting a selection side information associated with the core signal; a parameter generator for generating a parametric representation for estimating a spectral range of the frequency enhanced audio signal not defined by the core signal, wherein the parameter generator is configured to provide a number of parametric representation alternatives in response to the feature, and wherein the parameter generator is configured to select one of the parametric representation alternatives as the parametric representation in response to the selection side information; and a signal estimator for estimating the frequency enhanced audio signal using the parametric representation selected.

Abstract: This application describes methods and apparatus for mitigating the effects of crosstalk in multichannel audio. An audio driver circuit (200) for driving first and second audio loads (103) having a common return path (RC), has first and second signal paths (Left and Right). A crosstalk compensation block (205) is configured to add a first compensation signal to the first signal path and add a second compensation signal to the second signal path. The first compensation signal is generated based on the second audio signal and a first compensation function and the second compensation signal is generated based on the first audio signal and a second compensation function. Each of the first and second compensation functions is based on a predetermined impedance value for at least part of the common return path (RH1) and is also based on a determined DC impedance value (ZL, ZR) for one of the first and second audio loads which is modified by a band correction factor (?).

Abstract: A multi-channel decoder for generating a binaural signal from a downmix signal using upmix rule information on an energy-error introducing upmix rule for calculating a gain factor based on the upmix rule information and characteristics of head related transfer function based filters corresponding to upmix channels. The one or more gain factors are used by a filter processor for filtering the downmix signal so that an energy corrected binaural signal having a left binaural channel and a right binaural channel is obtained.

Abstract: An apparatus for decoding surround audio signal, includes a Bitstream De-multiplexer for unpacking a bitstream into spatial parameters and core parameters, a set of Core Decoder for decoding the core parameters into a set of core signal, a matrix derivation unit for deriving the rendering matrix from the spatial parameters and playback speaker layout information, a renderer for rendering of the decoded core signal to playback signals using the rendering matrix.

Abstract: A multi-channel decoder for generating a binaural signal from a downmix signal using upmix rule information on an energy-error introducing upmix rule for calculating a gain factor based on the upmix rule information and characteristics of head related transfer function based filters corresponding to upmix channels. The one or more gain factors are used by a filter processor for filtering the downmix signal so that an energy corrected binaural signal having a left binaural channel and a right binaural channel is obtained.

Abstract: An inter-channel level difference (ICLD) processing method and apparatus are disclosed. A stereo audio signal is received, and the stereo audio signal is parsed frame by frame, to obtain an ICLD of each sub-band of each subframe of each frame of the stereo audio signal; a sum of absolute values of the ICLDs of each subframe of any frame of the stereo audio signal is calculated; and when an absolute value of a difference between the sums of the absolute values of the ICLDs of each two subframes of the any frame is less than a preset threshold, a weighted ICLD value of each sub-band of the any frame is calculated in a first weighting manner; or otherwise, a weighted ICLD value of each sub-band of the any frame is calculated in a second weighting manner.

Abstract: A signal processing device includes: a calculating unit performing calculation using signal levels of first and second acoustic signals; a determining unit, based on a result of a comparison between: the signal level of at least one of the first and second acoustic signals before the calculation; and a result of the calculation, determining whether a component of a third acoustic signal to be output from a position between a position from which the first acoustic signal is output and a position from which the second acoustic signal is output is included in the first and second acoustic signals; and a signal generating unit generating the third acoustic signal from the first and second acoustic signals when the determining unit determines that the component of the third acoustic signal is included in the first and second acoustic signals.

Abstract: A method of encoding a multi-channel 3-dimensional (3D) audio signal mixed with a multi-channel 3D object signal is provided. The method includes: obtaining a location parameter indicating a virtual location of the multi-channel 3D object signal on a multi-channel speaker layout based on a gain value of the multi-channel 3D object signal for each channel; and encoding the multi-channel 3D audio signal and the location parameter.

Abstract: A multi-channel decoder for generating a binaural signal from a downmix signal using upmix rule information on an energy-error introducing upmix rule for calculating a gain factor based on the upmix rule information and characteristics of head related transfer function based filters corresponding to upmix channels. The one or more gain factors are used by a filter processor for filtering the downmix signal so that an energy corrected binaural signal having a left binaural channel and a right binaural channel is obtained.

Abstract: In general, techniques are described for signaling channels for scalable coding of higher order ambisonic audio data. A device comprising a memory and a processor may be configured to perform the techniques. The memory may be configured to store the bitstream. The processor may be configured to obtain, from the bitstream, an indication of a number of channels specified in one or more layers in the bitstream, and obtain the channels specified in the one or more layers in the bitstream based on the indication of the number of channels.

Abstract: A device includes a receiver and a decoder. The receiver is configured to receive stereo parameters encoded, by an encoder, based on a plurality of windows having a first length of overlapping portions between the plurality of windows. The decoder is configured to perform an upmix operation using the stereo parameters to generate at least two audio signals. The at least two audio signals are generated based on a second plurality of windows used in the upmix operation. The second plurality of windows has a second length of overlapping portions between the second plurality of windows. The second length is different from the first length.

Abstract: In general, techniques are described for coding higher-order ambisonic coefficients during multiple transitions. A device comprising a processor and a memory coupled to the processor may be configured to perform the techniques. The processor may be configured to obtain 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. The processor may also be configured to obtain a vector that describes a spatial characteristic of a corresponding foreground audio signal based on the multi-transition indication, both the vector and the corresponding HOA audio signal decomposed from the HOA audio data. The memory may be configured to store the vector.