28 results about "Ambisonics" patented technology

A decoding side method for spatial audio rendering using metadata, the method comprising: decoding a plurality of audio objects, a plurality of channels, or a high order ambisonics HOA representation

The invention relates to a panoramic sound space sound image positioning precision analysis method and device and electronic equipment. Comprising the following steps: determining sound image positioning positions, and acquiring an audio signal when a preset test audio is played at each sound image positioning position by using a head simulation audio acquisition device to obtain an audio signal pair of each sound image positioning position; calculating a time difference value and a sound pressure difference value of each position, and calculating an autopower spectrum of each audio signal pair by using Fourier transform; and carrying out region division on the spatial position and determining a weight, and obtaining a positioning precision analysis result according to a time difference value, a sound pressure difference value, a first autopower spectrum and a second autopower spectrum of each sound image positioning position and four parameter results of each position in a corresponding position in the ideal observer model. Therefore, the problems of consumption of a large amount of manpower and time cost, low precision, large result discreteness, difficulty in reproduction and the like in related technologies are solved, the influence of human subjective factors is eliminated, and the result has consistency, objectivity, stability and reproducibility.

An apparatus includes a memory configured to store first audio data and second audio data. The device also includes one or more processors coupled to the memory and configured to determine priorities of audio sources of the audio scene. The one or more processors are further configured to render the first audio data using the object renderer to generate a first audio signal. The first audio data represents a first audio source associated with a first priority. The one or more processors are further configured to render the second audio data using the first Ambisonics renderer to generate a second audio signal. The second audio data represents a second audio source associated with a second priority.

Dynamic range control (DRC) cannot be simply applied to higher-order ambisonics (HOA) based signals. [Solution] A method for performing DRC on an HOA signal includes converting the HOA signal to the spatial domain, analyzing the converted HOA signal, and obtaining a gain factor usable for dynamic compression from the results of the analysis. The gain factor can be transmitted together with the HOA signal. When DRC is applied, the HOA signal is converted to the spatial domain, the gain factor is extracted, and in the spatial domain, it is multiplied with the converted HOA signal to obtain a gain-compensated converted HOA signal. The gain-compensated converted HOA signal is converted back to the original HOA domain to obtain a gain-compensated HOA signal.

A spatial audio restoration device of an embodiment includes a video feature amount calculation unit that calculates a video feature amount on the basis of video information, an audio feature amount calculation unit that calculates an audio feature amount on the basis of audio information that is a monaural sound corresponding to the video information, and a coefficient calculation unit that calculates a high-order Ambisonics coefficient on the basis of the video feature amount and the audio feature amount.

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 localisation 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.

A sound scene is represented as first order Ambisonics (FOA) audio. A processor formats each signal of the FOA audio to a stream of audio frames, provides the formatted FOA audio to a machine learning model that reformats the formatted FOA audio in a target or desired higher order Ambisonics (HOA) format, and obtains output audio of the sound scene in the desired HOA format from the machine learning model. The output audio in the desired HOA format may then be rendered according to a playback audio format of choice. Other aspects are also described and claimed.

To provide a method and apparatus for decoding an Ambisonics audio soundfield representation for audio playback using a 2D setup.SOLUTION: For decoding, a decode matrix specific to the given loudspeaker setup is needed, which is generated using the known loudspeaker positions. A method for decoding an encoded audio signal in a sound field format for L loudspeakers at known positions comprises the steps of adding 10 at least one virtual loudspeaker position to the L loudspeaker positions, generating 11 a 3D decoding matrix D ', downmixing 12 said 3D decoding matrix D ', and decoding 14 the encoded audio signal 3D using the downscaled i14 decoding matrix to obtain a plurality of decoded loudspeaker signals q14.SELECTED DRAWING: Figure 1

The present document describes a method (400) for rendering an Ambisonics signal using a loudspeaker arrangement including S loudspeakers. The method (400) includes converting (401) a set of N Ambisonics channel signals (111) into a set of unfiltered pre-rendered signals (211), where N>1 and S>1. The method (400) further includes performing near-field compensation (referred to as NFC) filtering (402) of M unfiltered pre-rendered signals (211) of the set of unfiltered pre-rendered signals (211) to provide a set of S filtered loudspeaker channel signals (114) for rendering using the corresponding S loudspeakers.

A method including receiving an audio signal including a plurality of audio channels, selecting a first portion of the plurality of audio channels, selecting a second portion of the plurality of audio channels, generating first mixed audio channels by mixing the first portion of the plurality of audio channels with a first time-delayed audio channel, generating second mixed audio channels by mixing the second portion of the plurality of audio channels with a second time-delayed audio channel, and generating an augmented ambisonics model based on the plurality of audio channels, the first mixed audio channels, and the second mixed audio channels.

Make it possible to obtain a pseudo acoustic intensity vector using an acoustic signal collected by a wearable device. To this end, a pseudo-ambisonics signal generating apparatus according to the disclosed technology includes a spherical coordinate acquisition unit, a calculation unit, and a signal extraction unit. The spherical coordinate acquisition unit acquires spherical coordinates of each microphone with an intersection of a plane dividing a face symmetrically to the left and right and a straight line passing through the centers of left and right ears as an origin. The calculation unit calculates an average value of radii of the spherical coordinates, and replaces the radii of the spherical coordinates with the average values. The signal extraction unit generates a pseudo-ambisonics signal using the spherical coordinates replaced with the average values and acoustic signals acquired by the microphones.

A method that includes receiving a higher-order ambisonics (HOA) representation of a sound field that includes a first plurality of audio signals, separating a second plurality of audio signals from the first plurality of audio signals that are associated with a first-order ambisonics (FOA) representation of the sound field, determining a plurality of adaptive filters based on at least some of the second plurality of audio signals, producing a plurality of output audio signals based on the first plurality of audio signals and the plurality of adaptive filters, each output audio signal having at least a portion of the sound field, and driving a plurality of speakers using the plurality of output audio signals.

An apparatus for generating binaural audio based on a listener position within an audio scene, the apparatus comprising means configured to: obtain, for at least one audio source at least one audio source position from the audio scene; obtain a listener position within the audio scene, wherein the audio scene comprises: at least one internal region; and at least one external region, the regions defined with respect to the at least one audio source position; determine whether the listener position is located within the at least one internal region or at least one external region; determine whether the at least one audio source is available for rendering based on the determined listener position; determine a rendering mode based on the determination of the at least one audio source is available for rendering based on the determined listener position and whether the listener position is located within the at least one internal region or at least one external region; and render the binaural audio signal based on the determined rendering mode.

The invention improves HOA sound field representation compression and decompression. A decoder decodes compressed dominant directional signals and compressed residual component signals so as to provide decompressed dominant directional signals and decompressed time domain signals representing a residual HOA component in a spatial domain. A re-correlator re-correlates the decompressed time domain signals to obtain a corresponding reduced-order residual HOA component. A processor determines a decompressed residual HOA component based on the corresponding reduced-order residual HOA component, and determines predicted directional signals based on at least a parameter. The processor is further configured to determine an HOA sound field representation based on the decompressed dominant directional signals, the predicted directional signals, and the decompressed residual HOA component.

To provide a method and device for compressing and decompressing higher-order ambisonic representations that process directional and ambient components in different formats.SOLUTION: A compression method performs the process of estimating a dominant direction and decomposing an ambisonics signal C(l) into directional and ambient components in a dominant direction estimation section 22. I(L) indicates a frame index. The directional component is calculated in the directional signal calculation step or stage 23, the ambisonics representation is transformed into a time domain signal represented by a set of D normal directional signals X(l) and the corresponding direction, and the residual ambient component is calculated in an ambient HOA component calculation step or stage 24, is expressed by the HOA domain coefficients CA(l), and compression is performed. After that, it is order-extended to reconstruct the complete HOA representation from the direction signal, corresponding direction information and the ambient HOA components of an original order.SELECTED DRAWING: Figure 2

Encoding and decoding of higher order ambisonics, HOA, data for purposes of bitrate reduction. One aspect uses principal components analysis to produce spatial descriptors. Other aspects include various spatial descriptor quantization techniques.

A spatial surround sound system (100) with multiple speakers (110a to 110m) is disclosed, the multiple speakers including a front center speaker, a front left speaker, and a front right speaker, the spatial surround sound system (100) being used to generate spatial surround sound. The spatial surround sound system (100) includes processing circuitry for: generating multiple output audio signals for the multiple speakers (110a to 110m) based on multiple input audio signals, to render one or more audio objects according to corresponding positions associated with each audio object in a first rendering region employing a first audio rendering scheme and each audio object in a second rendering region employing a second audio rendering scheme. In order to generate the plurality of output audio signals for one or more audio objects in the first rendering area using the first audio rendering scheme, the processing circuit is configured to: render the one or more audio objects to a virtual speaker layout, wherein the virtual speaker layout includes the plurality of speakers (110a to 110m) other than the front center speaker; and upmix the virtual left front signal and the virtual right front signal to generate the corresponding output audio signals for the front left speaker, the front right speaker and the front center speaker.

This invention discloses a method and system for decoding immersive audio content encoded with an adaptive number of scene elements for channels, audio objects, high-order high-fidelity stereo reproduction (HOA), and / or other sound field representations. The decoded audio is presented to the speaker configuration of a playback device. For bitstreams representing audio scenes using different blends of channels, objects, and / or HOAs in consecutive frames, fade-in of new frames and fade-out of old frames can be performed. Crossfade-in and fade-out between consecutive frames occur: in speaker layouts after rendering, in spatially decoded content types before rendering, or as the output of a baseline decoder but between delivery channels before spatial decoding and rendering. Crossfade-in and fade-out can use immediate fade-in and fade-out frames (IFFF) for transition frames, or can use overlapping additive synthesis techniques such as temporal aliasing cancellation (TDAC) for MDCT.

The present invention provides a method and apparatus for compressing and decompressing higher-order ambisonics (HOA) representations, which process directional and ambient components in different formats. [Solution] The compression method involves a dominant direction estimation unit 22 that estimates the dominant direction and performs a process to decompose the ambisonic signal C(l) into a directional component and an ambient component. The directional component is calculated in stage 23, thereby determining the direction of the ambisonic representation. TIFF2026069501000138.tif7153 The signal is converted into a time-domain signal represented by the above, and the residual ambient component is calculated in stage 24, and the HOA domain coefficient C is calculated. A Expressed by (l).

A time-of-flight (TOF) array including a plurality of cameras is positioned with a coplanar Higher Order Ambisonics (HOA) array including a plurality of microphones above a target area such as a room or space for analyzing speaker activity in that area. The HOA microphone array iteratively samples sound energy level frames captured by the microphones to identify a sound vector associated with the global maximum energy level in the sound energy level frame. This sound vector is fused with the data from the TOF camera array that identified the positions of sound sources in the target area to associate produced sound corresponding with the sound vector with a physical active sound source in the target area. A beamformer can then be used to save audio corresponding to the sound vector and discard audio not associated with the sound vector to produce a sound recording associated with the active sound source.

To solve such a problem that dynamic range control (DRC) cannot be applied simply to a signal of high order ambisonics (HOA) based signal.SOLUTION: A method for executing DRC of a HOA signal includes to convert the HOA signal into space region, to analyze the converted HOA signal, and to obtain a gain factor usable for dynamic compression from the analysis results. The gain factor can be transmitted together with the HOA signal. When the DRC is applied, the HOA signal is converted into the space region, the gain factor is extracted, and multiplied by the converted HOA signal in the space region, thus obtaining a converted HOA signal subjected to gain compensation. The converted HOA signal subjected to gain compensation is converted into the original HOA region, thus obtaining a HOA signal subjected to gain compensation.SELECTED DRAWING: Figure 2

To provide a method for decompressing a compressed HOA signal and an apparatus for decompressing a compressed HOA signal.SOLUTION: A method for compressing an HOA signal, which is an input HOA representation with input time frames (C (k)) of HOA coefficient sequences, includes a spatial HOA encoding of the input time frames and subsequent perceptual and source encoding. Each input time frame is decomposed (802) into a frame of predominant sound signals (XPS (k-1)) and a frame of ambient HOA component (CAMB (k-1)). The ambient HOA component (CAMB (k - 1)) comprises, in the layered mode, first HOA coefficient sequences of the input HOA representation (c n (k - 1)) in lower positions and second HOA coefficient sequences (CAMB, n (k - 1)) in remaining higher positions. The second HOA coefficient sequences are part of a HOA representation of a residual between the input HOA representation and the HOA representation of the predominant sound signals.SELECTED DRAWING: Figure 5

A method includes receiving an ambisonics recording within a scene. The ambisonics recording includes a target sound and other sounds in the scene. The method includes receiving directional parameters indicating a direction of a source of the target sound in the scene. The method includes receiving a text description of the target sound within the scene. The method includes processing, using a semantic encoder, the text description of the target sound to generate a semantic embedding vector. The method includes concatenating the semantic embedding vector with the directional parameters to generate a conditioning vector. The method includes processing, using a neural network conditioned on the conditioning vector, the ambisonics recording to generate an enhanced audio signal that isolates the target sound in the scene from the other sounds in the scene.

To provide a method and apparatus for determining a minimum integer number of bits required to represent non-differential gain values for compression of a Higher Order Ambisonics (HOA) data frame representation.SOLUTION: When compressing the HOA data frame representation in the HOA compressor, a gain control 15, 151 is applied for each channel signal before it is perceptually encoded 16. Those gain values should be encoded with a minimum number of bits, and in order to determine such a lowest integer number of bits (β e), the HOA data frame representation (C (K)) is rendered in the spatial domain to virtual loudspeaker signals on a unit sphere, following which the HOA component is normalized to the directional signal data frame representation (C (K)). Then, the lowest integer number of bits is set to β e = [log2 ([log2 ({√ KMAX}·O)] + 1)].SELECTED DRAWING: Figure 1

A method that includes receiving audio content in a first-order ambisonics (FOA) format that includes a first plurality of audio signals, producing a plurality of spatially rendered audio signals by spatially rendering the first plurality of audio signals according to a layout of a virtual loudspeaker array, determining one or more filters by performing a parametric analysis upon at least one of the first plurality of audio signals, filtering at least one of the plurality of spatially rendered audio signals using the one or more filters; and producing a second plurality of audio signals in a higher-order ambisonics (HOA) format based on the plurality of spatially rendered audio signals.