# US 10,504,527 B2 · Audio signal decoder, audio signal encoder, method for providing an upmix signal representation, method for providing a downmix signal representation, computer program and bitstream using a common inter-object-correlation parameter value > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,504,527 B2 - Document ID: US10504527B2 - Status: Granted - Kind: B2 - Application number: 15/730,652 - Filed: 2017-10-11 - Published: 2018-02-01 - Granted: 2019-12-10 - Earliest claimed: 2009-09-29 - Assignees: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.; Dolby International AB - Applicants: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.; Dolby International AB - Inventors: Juergen Herre; Johannes Hilpert; Andreas Hoelzer; Jonas Engdegard; Heiko Purnhagen - Web page: https://patentgrep.com/patent/US10504527B2 ## CPC - G10L 19/008: Multichannel audio signal coding or decoding using interchannel correlation to reduce redundancy, e.g. joint-stereo, intensity-coding or matrixing - G10L 19/005: Correction of errors induced by the transmission channel, if related to the coding algorithm - G10L 19/20: using sound class specific coding, hybrid encoders or object based coding - H04S 3/02: of the matrix type, i.e. in which input signals are combined algebraically, e.g. after having been phase shifted with respect to each other - H04S 5/005: {of the pseudo five- or more-channel type, e.g. virtual surround} - H04S 2420/03: Application of parametric coding in stereophonic audio systems - G10L: SPEECH ANALYSIS TECHNIQUES OR SPEECH SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING TECHNIQUES; SPEECH OR AUDIO CODING OR DECODING - H04S: STEREOPHONIC SYSTEMS ## Abstract An audio signal decoder for providing an upmix signal representation on the basis of a downmix signal representation and an object-related parametric information and in dependence on a rendering information has an object parameter determinator. The object parameter determinator is configured to obtain inter-object-correlation values for a plurality of pairs of audio objects. The object parameter determinator is configured to evaluate a bitstream signaling parameter in order to decide whether to evaluate individual inter-object-correlation bitstream parameter values to obtain inter-object-correlation values for a plurality of pairs of related audio objects, or to obtain inter-object-correlation values for a plurality of pairs of related audio objects using a common inter-object-correlation bitstream parameter value. The audio signal decoder also has a signal processor configured to obtain the upmix signal representation on the basis of the downmix signal representation and using the inter-object-correlation values for a plurality of pairs of related objects and the rendering information. ## Claims ### Claim 1 An audio signal decoder for providing an upmix signal representation based on a downmix signal representation and an object-related parametric information, and depending on a rendering information, the audio signal decoder comprising: an object parameter determinator configured to acquire inter-object-correlation values for a plurality of pairs of audio objects, wherein the object parameter determinator is configured to evaluate a bitstream signaling parameter in order to decide whether to evaluate individual inter-object-correlation bitstream parameter values, to acquire inter-object-correlation values for a plurality of pairs of related audio objects, or to acquire inter-object-correlation values for the plurality of pairs of related audio objects using a common inter-object-correlation bitstream parameter value; and a signal processor configured to acquire the upmix signal representation based on the downmix signal representation and using the inter-object-correlation values for the plurality of pairs of related audio objects and the rendering information; wherein the object parameter determinator is configured to evaluate an object-relationship-information, describing whether two audio objects are related to each other; and wherein the object parameter determinator is configured to selectively acquire inter-object-correlation values for pairs of audio objects, for which the object-relationship-information indicates a relationship, using the common inter-object-correlation bitstream parameter value. ### Claim 2 (depends on 1) The audio decoder according to claim 1, wherein the object parameter determinator is configured to evaluate the object-relationship information comprising a one-bit flag for each combination of different audio objects, wherein the one-bit flag associated to a given combination of different audio objects indicates whether the audio objects of the given combination are related or not. ### Claim 3 (depends on 1) The audio decoder according to claim 1, wherein the object parameter determinator is configured to set the inter-object-correlation value for all pairs of different related audio objects to a common value defined by the common inter-object-correlation bitstream parameter value, or to a value derived from the common value defined by the common inter-object-correlation bitstream parameter value. ### Claim 4 (depends on 1) The audio decoder according to claim 1, wherein the object parameter determinator comprises a bitstream parser configured to parse a bitstream representation of an audio content, to acquire the bitstream signaling parameter and the individual inter-object-correlation bitstream parameter values or the common inter-object-correlation bitstream parameter value. ### Claim 5 (depends on 1) The audio decoder according to claim 1, wherein the audio signal decoder is configured to combine an inter-object-correlation value IOCi,j associated with a pair of related audio objects with an object level difference value OLDi describing an object level of a first audio object of the pair of related audio objects and with an object level difference value OLDj describing an object level of a second audio object of the pair of related audio objects, to acquire a covariance value ei,j associated with the pair of related audio objects; wherein the audio decoder is configured to acquire an element ei,j of a covariance matrix according to ei,j=√{square root over (OLDiOLDj)}IOCi,j. ### Claim 6 (depends on 1) The audio signal decoder according to claim 1, wherein the audio signal decoder is configured to handle three or more audio objects; and wherein the object parameter determinator is configured to provide an inter-object-correlation value for every pair of different audio objects. ### Claim 7 (depends on 1) The audio signal decoder according to claim 1, wherein the object parameter determinator is configured to evaluate the bitstream signaling parameter, which is comprised in a configuration bitstream portion, in order to decide whether to evaluate the individual inter-object-correlation bitstream parameter values to acquire the inter-object-correlation values for a plurality of pairs of related audio objects, or to acquire the inter-object-correlation values for a plurality of pairs of related audio objects using the common inter-object-correlation bitstream parameter value; and wherein the object parameter determinator is configured to evaluate an object relationship information, which is comprised in the configuration bitstream portion, to determine whether two audio objects are related; and wherein the object parameter determinator is configured to evaluate a common inter-object-correlation bitstream parameter value, which is comprised in a frame data bitstream portion for every frame of the audio content, if it is decided to acquire inter-object-correlation values for a plurality of pairs of related audio objects using a common inter-object-correlation bitstream parameter value. ### Claim 8 An audio signal encoder for providing a bitstream representation based on a plurality of audio object signals, the audio signal encoder comprising: a parameter provider configured to provide a common inter-object-correlation bitstream parameter value associated with a plurality of pairs of related audio object signals, and to also provide a bitstream signaling parameter indicating that the common inter-object-correlation bitstream parameter value is provided instead of a plurality of individual inter-object-correlation bitstream parameter values; wherein the parameter provider is configured to also provide an object relationship information describing whether two audio objects are related to each other; and a bitstream formatter configured to provide a bitstream comprising a representation of a downmix signal, a representation of the common inter-object-correlation bitstream parameter value and the bitstream signaling parameter. ### Claim 9 (depends on 8) The audio signal encoder according to claim 8, wherein the parameter provider is configured to provide the common inter-object-correlation bitstream parameter value in dependence on a ratio between a sum of cross power terms and a sum of average power terms. ### Claim 10 (depends on 9) The audio signal encoder according to claim 9, wherein the parameter provider is configured to compute the cross power term for a given pair of audio objects by evaluating a sum of products of spectral coefficients associated with audio objects of the given pair of audio objects over a plurality of time instances, or over a plurality of frequency instances; and wherein the parameter provider is configured to compute the average power term for the given pair of audio objects by evaluating a geometric mean of a power value representing the power of a first audio object over a plurality of time instances or over a plurality of frequency instances, and of a power value representing the power of a second audio object over a plurality of time instances or over a plurality of frequency instances. ### Claim 11 (depends on 9) The audio signal encoder according to claim 9, wherein the parameter provider is configured to provide the common inter-object-correlation bitstream parameter value IOCsingle according to IOC single = Re ⁢ { ∑ i = 1 N ⁢ ⁢ ∑ j = i + 1 N ⁢ ⁢ nrg ij ∑ i = 1 N ⁢ ⁢ ∑ j = i + 1 N ⁢ nrg ii ⁢ nrg jj } wherein, nrg ij = ∑ n ⁢ ⁢ ∑ k ⁢ ⁢ S i n , k ⁡ ( S j n , k ) * wherein n and k describe time and frequency instances for which an SAOC parameter applies; and wherein sin,k is a spectral value associated with time instance n and frequency instance k of the audio object comprising audio object index i; wherein sjnk is a spectral value associated with time instance n and frequency instance k of the audio object comprising audio object index j; wherein N designates a total number of audio objects. ### Claim 12 (depends on 8) The audio signal encoder according to claim 8, wherein the parameter provider is configured to provide a predetermined constant value as the common inter-object-correlation bitstream parameter value. ### Claim 13 (depends on 8) The audio signal encoder according to claim 8, wherein the parameter provider is configured to selectively evaluate an inter-object-correlation of audio objects, for which the object relationship information indicates a relationship, for a computation of the common inter-object-correlation bitstream parameter value. ### Claim 14 A method for providing an upmix signal representation based on a downmix signal representation and an object-related parametric information and in dependence on a rendering information, the method comprising: acquiring inter-object-correlation values for a plurality of pairs of audio objects, wherein a bitstream signaling parameter is evaluated in order to decide whether to evaluate individual inter-object-correlation bitstream parameter values, to acquire inter-object-correlation values for a plurality of pairs of related audio objects, or to acquire inter-object-correlation values for the plurality of pairs of related audio objects using a common inter-object-correlation bitstream parameter value; and acquiring the upmix signal representation based on the downmix signal representation and using the inter-object-correlation values for the plurality of pairs of related audio objects and the rendering information; wherein an object-relationship information, describing whether two audio objects are related to each other, is evaluated, and wherein the inter-object-correlation values are selectively acquired for pairs of audio objects, for which the object relationship-information indicates a relationship, using the common inter-object-correlation bitstream parameter value wherein the method is performed using a hardware apparatus, or using a computer, or using a combination of a hardware apparatus and a computer. ### Claim 15 A method for providing a bitstream representation based on a plurality of audio object signals, the method comprising: providing a common inter-object-correlation bitstream parameter value associated with a plurality of pairs of related audio object signals; and providing a bitstream signaling parameter indicating that the common inter-object-correlation bitstream parameter value is provided instead of a plurality of individual inter-object-correlation bitstream parameter values; and providing an object-relationship information describing whether two audio objects are related to each other, providing a bitstream comprising a representation of a downmix signal, a representation of the common inter-object-correlation bitstream parameter value and the bitstream signaling parameter, wherein the method is performed using a hardware apparatus, or using a computer, or using a combination of a hardware apparatus and a computer. ### Claim 16 A non-transitory digital storage medium having a computer program stored thereon for performing the method for providing an upmix signal representation based on a downmix signal representation and an object-related parametric information and in dependence on a rendering information, the method comprising: acquiring inter-object-correlation values for a plurality of pairs of audio objects, wherein a bitstream signaling parameter is evaluated in order to decide whether to evaluate individual inter-object-correlation bitstream parameter values, to acquire inter-object-correlation values for a plurality of pairs of related audio objects, or to acquire inter-object-correlation values for the plurality of pairs of related audio objects using a common inter-object-correlation bitstream parameter value; and acquiring the upmix signal representation based on the downmix signal representation and using the inter-object-correlation values for the plurality of pairs of related audio objects and the rendering information; wherein an object-relationship information, describing whether two audio objects are related to each other, is evaluated, and wherein the inter-object-correlation values are selectively acquired for pairs of audio objects, for which the object relationship-information indicates a relationship, using the common inter-object-correlation bitstream parameter value when the computer program runs on a computer. ### Claim 17 A non-transitory digital storage medium having a computer program stored thereon for performing the method for providing a bitstream representation based on a plurality of audio object signals, the method comprising: providing a common inter-object-correlation bitstream parameter value associated with a plurality of pairs of related audio object signals; and providing a bitstream signaling parameter indicating that the common inter-object-correlation bitstream parameter value is provided instead of a plurality of individual inter-object-correlation bitstream parameter values; and providing an object-relationship information describing whether two audio objects are related to each other, providing a bitstream comprising a representation of a downmix signal, a representation of the common inter-object-correlation bitstream parameter value and the bitstream signaling parameter, when the computer program runs on a computer. ### Claim 18 A non-transitory digital storage medium having a computer program stored thereon for performing the method of providing an upmix signal representation on the basis of a downmix signal representation and an object-related parametric information and in dependence on a rendering information, the method comprising: acquiring inter-object-correlation values for a plurality of pairs of audio objects, wherein a bitstream signaling parameter is evaluated in order to decide whether to evaluate individual inter-object-correlation bitstream parameter values, to acquire inter-object-correlation values for a plurality of pairs of related audio objects, or to acquire inter-object-correlation values for a plurality of pairs of related audio objects using a common inter-object-correlation bitstream parameter value; and acquiring the upmix signal representation on the basis of the downmix signal representation and using the inter-object-correlation values for a plurality of pairs of related audio objects and the rendering information; wherein an inter-object-correlation value IOCi,j associated with a pair of related audio objects is combined with an object level difference value OLDi describing an object level of a first audio object of the pair of related audio objects and with an object level difference value OLDj describing an object level of a second audio object of the pair of related audio objects, to acquire a covariance value ei,j associated with the pair of related audio objects; wherein an element ei,j of a covariance matrix is acquired according to ei,j=√{square root over (OLDiOLDj)}IOCi,j; wherein the object-related parametric information comprises the bitstream signaling parameter and the individual inter-object-correlation bitstream parameter values or the common inter-object-correlation bitstream parameter value, when the computer program runs on a computer.