Spatial rendering of reverberation

Abstract

A method for an apparatus for spatial rendering of reverberation, the method comprising: obtaining a bitstream for a virtual scene, the bitstream for a virtual scene comprising at least one reverberation parameter associated with a first acoustic environment, and at least one acoustic space connection information associated with the first acoustic environment; obtaining at least one second acoustic environment and associated position data; associating the second acoustic environment with the first acoustic environment based on at least one of the associated position data and the at least one acoustic space connection information; determining at least first reverberation processing based on the association between the second acoustic environment and the first acoustic environment; and generating a reverberated audio signal based on the at least one reverberation parameter and the at least first reverberation processing applied to at least one sound source audio signal.

Description

[0001] SPATIAL RENDERING OF REVERBERATION

[0002] Field

[0003] The present application relates to apparatus and methods for association of acoustic environments with acoustic space connection information (defining an acoustic portal), but not exclusively for association of acoustic environments with acoustic space connection information in augmented reality and / or virtual reality apparatus.

[0004] Background

[0005] Reverberation refers to the persistence of sound in a space after the actual sound source has stopped. Different spaces are characterized by different reverberation characteristics. For conveying spatial impression of an environment, reproducing reverberation perceptually accurately is important. Room acoustics are often modelled with individually synthesized early reflection portion and a statistical model for the diffuse late reverberation. Figure 1 depicts an example of a synthesized room impulse response showing amplitude 101 over time 103 where the direct sound 105 is followed by discrete early reflections 107 which have a direction of arrival (DOA) and diffuse late reverberation 109 which can also have a direction of arrival or be synthesized without any specific direction of arrival.

[0006] In other words after the direct sound, the listener would hear directional early reflections. After some point, individual reflections can no longer be perceived but the listener hears diffuse, late reverberation. The starting time of the diffuse late reverberation can be referred to as the predelay, diffuseness onset or mixing time.

[0007] The reverberation can be rendered using, e.g., a Feedback-Delay-Network (FDN) reverberator with a suitable tuning of delay line lengths. FDNs enable a controlling of the reverberation times (RT60) and the energies of different frequency bands individually. Thus, it can be used to render the reverberation based on the characteristics of the room. The reverberation times and the energies of the different frequencies are affected by the frequency-dependent absorption characteristics of the room.

[0008] Reverberation spectrum or level can be controlled using the diffuse-to-direct ratio, which describes the ratio of the energy (or level) of reverberant sound energy to the direct sound energy (or the total emitted energy of a sound source). It has been defined, for example within N0182 MPEG-I Immersive Audio Encoder Input Format, that an input to an encoder is provided as a diffuse-to-source energy ratio (DSR) value which indicates the ratio of the diffuse (reverberant) sound energy to the total emitted energy of a sound source. Another well-known measure is the RDR which refers to reverberant-to-direct ratio and which can be measured from an impulse response. The relation between the RDR and DSR values is, described in N0083_MPEG-l Immersive Audio CfP Supplemental Information, Recommendations and Clarifications, Version 1 , and can be represented as:

[0009] 10*log10(RDR) = 10*log10(DSR) - 41 dB.

[0010] Referring to Figure 1 , the RDR can be calculated by: summing the squares of the sample values of the diffuse late reverberation portion 105; summing the squares of the sample values of the direct sound portion 101 ; and calculating the ratio of these two sums to give the RDR.

[0011] The logarithmic RDR can be obtained as 10*log10(RDR). Reverberation ratio can refer to the RDR or DSR or other suitable ratio between direct and diffuse / reverberant energy or signal level.

[0012] In a virtual environment for virtual reality (VR) or a real physical environment for augmented reality (AR) there can be several acoustic environments, each with their own reverberation parameters which can be different in different acoustic environments. This kind of environment can be rendered with multiple reverberators running in parallel, so that a reverberator instance is running in each acoustic environment. When the listener is moving in the environment, the current environment reverberation is rendered as an enveloping spatial sound surrounding the user, and the reverberation from nearby acoustic spaces is rendered via so called acoustic portals. The acoustic portal or window is a connection between two spaces.

[0013] Summary

[0014] There is provided according to a first aspect a method for an apparatus for spatial rendering of reverberation, the method comprising: obtaining a bitstream for a virtual scene, the bitstream for a virtual scene comprising at least one reverberation parameter associated with a first acoustic environment, and at least one acoustic space connection information associated with the first acoustic environment; obtaining at least one second acoustic environment and associated position data; associating the second acoustic environment with the first acoustic environment based on at least one of the associated position data and the at least one acoustic space connection information; determining at least first reverberation processing based on the association between the second acoustic environment and the first acoustic environment; and generating a reverberated audio signal based on the at least one reverberation parameter and the at least first reverberation processing applied to at least one sound source audio signal.

[0015] The at least one second acoustic environment may be listener space acoustic information and the associated position data comprises anchor position data.

[0016] The at least one acoustic space connection information may be for indicating at least part of the first acoustic environment is available for being coupled to at least one further acoustic environment.

[0017] The at least one acoustic space connection information associated with the first acoustic environment may define at least one portal associated with the first acoustic environment.

[0018] Associating the second acoustic environment with the first acoustic environment based on the associated position data and the at least one acoustic space connection information may comprise determining the at least one portal is defined only with respect to the first acoustic environment.

[0019] The listener space information associated with a listener space acoustic environment may comprise an anchor element defined by an anchor identifier and / or anchor position.

[0020] Associating the second acoustic environment with the first acoustic environment based on the listener space information and the at least one acoustic space connection may comprise: determining the at least one portal extent is within the anchor element identified by the anchor identifier; and determining portal connection information between the second acoustic environment and the first acoustic environment based on the listener space information and the at least one acoustic space connection information.

[0021] Determining the portal extent is within the anchor element identified by the at least one anchor identifier may further comprise determining the at least one portal is within a proximity distance threshold of the extent of the anchor element identified by the at least one anchor identifier.

[0022] The at least one reverberation parameter associated with a first acoustic environment may comprise one or more of: reverberation time values values; reverberation ratio values values; dimension values associated with the at least first acoustic environment.

[0023] Determining the at least first reverberation processing based on the association between the second acoustic environment with the first acoustic environment may comprise determining an audio source within the first acoustic environment as an external source for the second acoustic environment and inputting an audio signal from the external source to at least one second acoustic environment reverberator controlled by at least one reverberation parameter.

[0024] Determining the at least first reverberation processing based on the association between the second acoustic environment with the first acoustic environment may comprise determining leaking at least one reverberated audio signal from the first acoustic environment to the to at least one second acoustic environment reverberator controlled by at least one reverberation parameter.

[0025] The method may further comprise determining a second reverberation parameter associated with the second acoustic environment and modifying the second reverberation parameter to obtain a modified second acoustic parameter such that modified second acoustic parameter is not substantially similar to the first acoustic parameter.

[0026] According to a second aspect there is provided an apparatus for spatial rendering of reverberation, the apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the system at least to perform: obtaining a bitstream for a virtual scene, the bitstream for a virtual scene comprising at least one reverberation parameter associated with a first acoustic environment, and at least one acoustic space connection information associated with the first acoustic environment; obtaining at least one second acoustic environment and associated position data; associating the second acoustic environment with the first acoustic environment based on at least one of the associated position data and the at least one acoustic space connection information; determining at least first reverberation processing based on the association between the second acoustic environment and the first acoustic environment; and generating a reverberated audio signal based on the at least one reverberation parameter and the at least first reverberation processing applied to at least one sound source audio signal.

[0027] The at least one second acoustic environment is listener space acoustic information and the associated position data may comprise anchor position data.

[0028] The at least one acoustic space connection information may be for indicating at least part of the first acoustic environment is available for being coupled to at least one further acoustic environment.

[0029] The at least one acoustic space connection information associated with the first acoustic environment may define at least one portal associated with the first acoustic environment.

[0030] The apparatus caused to perform associating the second acoustic environment with the first acoustic environment based on the associated position data and the at least one acoustic space connection information may be further caused to perform determining the at least one portal is defined only with respect to the first acoustic environment.

[0031] The listener space information associated with a listener space acoustic environment may comprise an anchor element defined by an anchor identifier and / or anchor position.

[0032] The apparatus caused to perform associating the second acoustic environment with the first acoustic environment based on the listener space information and the at least one acoustic space connection may be further caused to perform: determining the at least one portal extent is within the anchor element identified by the anchor identifier; and determining portal connection information between the second acoustic environment and the first acoustic environment based on the listener space information and the at least one acoustic space connection information. The apparatus caused to perform determining the portal extent is within the anchor element identified by the at least one anchor identifier may be further caused to perform determining the at least one portal is within a proximity distance threshold of the extent of the anchor element identified by the at least one anchor identifier.

[0033] The at least one reverberation parameter associated with a first acoustic environment may comprise one or more of: reverberation time values values; reverberation ratio values values; dimension values associated with the at least first acoustic environment.

[0034] The apparatus caused to perform determining the at least first reverberation processing based on the association between the second acoustic environment with the first acoustic environment may be caused to perform determining an audio source within the first acoustic environment as an external source for the second acoustic environment and inputting an audio signal from the external source to at least one second acoustic environment reverberator controlled by at least one reverberation parameter.

[0035] The apparatus caused to perform determining the at least first reverberation processing based on the association between the second acoustic environment with the first acoustic environment may be caused to perform determining leaking at least one reverberated audio signal from the first acoustic environment to the to at least one second acoustic environment reverberator controlled by at least one reverberation parameter.

[0036] The apparatus may be further caused to perform determining a second reverberation parameter associated with the second acoustic environment and modifying the second reverberation parameter to obtain a modified second acoustic parameter such that modified second acoustic parameter is not substantially similar to the first acoustic parameter.

[0037] According to a third aspect there is provided an apparatus for spatial rendering of reverberation, the apparatus comprising means configured to: obtain a bitstream for a virtual scene, the bitstream for a virtual scene comprising at least one reverberation parameter associated with a first acoustic environment, and at least one acoustic space connection information associated with the first acoustic environment; obtain at least one second acoustic environment and associated position data; associate the second acoustic environment with the first acoustic environment based on at least one of the associated position data and the at least one acoustic space connection information; determine at least first reverberation processing based on the association between the second acoustic environment and the first acoustic environment; and generate a reverberated audio signal based on the at least one reverberation parameter and the at least first reverberation processing applied to at least one sound source audio signal.

[0038] The at least one second acoustic environment is listener space acoustic information and the associated position data may comprise anchor position data.

[0039] The at least one acoustic space connection information may be for indicating at least part of the first acoustic environment is available for being coupled to at least one further acoustic environment.

[0040] The at least one acoustic space connection information associated with the first acoustic environment may define at least one portal associated with the first acoustic environment.

[0041] The means configured to associate the second acoustic environment with the first acoustic environment based on the associated position data and the at least one acoustic space connection information may be further configured to determine the at least one portal is defined only with respect to the first acoustic environment.

[0042] The listener space information associated with a listener space acoustic environment may comprise an anchor element defined by an anchor identifier and / or anchor position.

[0043] The means configured to associate the second acoustic environment with the first acoustic environment based on the listener space information and the at least one acoustic space connection may be further configured to: determine the at least one portal extent is within the anchor element identified by the anchor identifier; and determine portal connection information between the second acoustic environment and the first acoustic environment based on the listener space information and the at least one acoustic space connection information.

[0044] The means configured to determine the portal extent is within the anchor element identified by the at least one anchor identifier may be further configured to determine the at least one portal is within a proximity distance threshold of the extent of the anchor element identified by the at least one anchor identifier.

[0045] The at least one reverberation parameter associated with a first acoustic environment may comprise one or more of: reverberation time values values; reverberation ratio values values; dimension values associated with the at least first acoustic environment.

[0046] The means configured to determine the at least first reverberation processing based on the association between the second acoustic environment with the first acoustic environment may be configured to determine an audio source within the first acoustic environment as an external source for the second acoustic environment and inputting an audio signal from the external source to at least one second acoustic environment reverberator controlled by at least one reverberation parameter.

[0047] The means configured to determine the at least first reverberation processing based on the association between the second acoustic environment with the first acoustic environment may be configured to determine leaking at least one reverberated audio signal from the first acoustic environment to the to at least one second acoustic environment reverberator controlled by at least one reverberation parameter.

[0048] The means may be further configured to determine a second reverberation parameter associated with the second acoustic environment and modifying the second reverberation parameter to obtain a modified second acoustic parameter such that modified second acoustic parameter is not substantially similar to the first acoustic parameter.

[0049] According to a fourth aspect there is provided an apparatus for spatial rendering of reverberation, the apparatus comprising: obtaining circuitry configured to obtain a bitstream for a virtual scene, the bitstream for a virtual scene comprising at least one reverberation parameter associated with a first acoustic environment, and at least one acoustic space connection information associated with the first acoustic environment; obtaining circuitry configured to obtain at least one second acoustic environment and associated position data; associating circuitry configured to associate the second acoustic environment with the first acoustic environment based on at least one of the associated position data and the at least one acoustic space connection information; determining circuitry configured to determine at least first reverberation processing based on the association between the second acoustic environment and the first acoustic environment; and generating circuitry configured to generate a reverberated audio signal based on the at least one reverberation parameter and the at least first reverberation processing applied to at least one sound source audio signal.

[0050] According to a fifth aspect there is provided a computer program comprising instructions [or a computer readable medium comprising instructions] for causing an apparatus, for spatial rendering of reverberation, the apparatus caused to perform at least the following: obtaining a bitstream for a virtual scene, the bitstream for a virtual scene comprising at least one reverberation parameter associated with a first acoustic environment, and at least one acoustic space connection information associated with the first acoustic environment; obtaining at least one second acoustic environment and associated position data; associating the second acoustic environment with the first acoustic environment based on at least one of the associated position data and the at least one acoustic space connection information; determining at least first reverberation processing based on the association between the second acoustic environment and the first acoustic environment; and generating a reverberated audio signal based on the at least one reverberation parameter and the at least first reverberation processing applied to at least one sound source audio signal.

[0051] According to a sixth aspect there is provided a non-transitory computer readable medium comprising program instructions for causing an apparatus, for spatial rendering of reverberation, the apparatus caused to perform at least the following: obtaining a bitstream for a virtual scene, the bitstream for a virtual scene comprising at least one reverberation parameter associated with a first acoustic environment, and at least one acoustic space connection information associated with the first acoustic environment; obtaining at least one second acoustic environment and associated position data; associating the second acoustic environment with the first acoustic environment based on at least one of the associated position data and the at least one acoustic space connection information; determining at least first reverberation processing based on the association between the second acoustic environment and the first acoustic environment; and generating a reverberated audio signal based on the at least one reverberation parameter and the at least first reverberation processing applied to at least one sound source audio signal.

[0052] According to a seventh aspect there is provided an apparatus, for spatial rendering of reverberation, the apparatus caused to perform at least the following:, comprising: means for obtaining a bitstream for a virtual scene, the bitstream for a virtual scene comprising at least one reverberation parameter associated with a first acoustic environment, and at least one acoustic space connection information associated with the first acoustic environment; means for obtaining at least one second acoustic environment and associated position data; means for associating the second acoustic environment with the first acoustic environment based on at least one of the associated position data and the at least one acoustic space connection information; means for determining at least first reverberation processing based on the association between the second acoustic environment and the first acoustic environment; and means for generating a reverberated audio signal based on the at least one reverberation parameter and the at least first reverberation processing applied to at least one sound source audio signal.

[0053] According to an eighth aspect there is provided a computer readable medium comprising instructions for causing an apparatus, for spatial rendering of reverberation, the apparatus caused to perform at least the following: obtaining a bitstream for a virtual scene, the bitstream for a virtual scene comprising at least one reverberation parameter associated with a first acoustic environment, and at least one acoustic space connection information associated with the first acoustic environment; obtaining at least one second acoustic environment and associated position data; associating the second acoustic environment with the first acoustic environment based on at least one of the associated position data and the at least one acoustic space connection information; determining at least first reverberation processing based on the association between the second acoustic environment and the first acoustic environment; and generating a reverberated audio signal based on the at least one reverberation parameter and the at least first reverberation processing applied to at least one sound source audio signal.

[0054] An apparatus comprising means for performing the actions of the method as described above. An apparatus configured to perform the actions of the method as described above.

[0055] A computer program comprising instructions for causing a computer to perform the method as described above.

[0056] A computer program product stored on a medium may cause an apparatus to perform the method as described herein.

[0057] An electronic device may comprise apparatus as described herein.

[0058] A chipset may comprise apparatus as described herein.

[0059] Embodiments of the present application aim to address problems associated with the state of the art.

[0060] Summary of the Figures

[0061] For a better understanding of the present application, reference will now be made by way of example to the accompanying drawings in which:

[0062] Figure 1 shows a model of room acoustics and the room impulse response;

[0063] Figure 2 shows an example environment comprising multiple acoustic environments coupled via an acoustic portal;

[0064] Figures 3a and 3b shows an example environment comprising multiple acoustic environments (bitstream and LSDF defined) suitable for demonstrating some embodiments;

[0065] Figures 4a and 4b show schematically an example apparatus within which some embodiments may be implemented;

[0066] Figure 5 shows a flow diagram of the operation of the example apparatus as shown in Figure 4a and 4b in further detail according to some embodiments;

[0067] Figure 6 shows a flow diagram of the operation of the example apparatus as shown in Figure 4a and 4b in further detail according to some embodiments;

[0068] Figure 7 shows a further example environment comprising multiple acoustic environments (bitstream and LSDF defined) suitable for demonstrating some embodiments;

[0069] Figure 8 shows schematically an example apparatus with transmission and / or storage within which some embodiments can be implemented; and

[0070] Figure 9 shows an example device suitable for implementing the apparatus shown in previous figures. Embodiments of the Application

[0071] The following describes in further detail suitable apparatus and possible mechanisms for implementing reverberation in audio scenes with multiple acoustic environments and where two or more acoustic environments are acoustically coupled.

[0072] As discussed above several virtual (for VR) or physical (for AR) acoustic environments can be rendered with several digital reverberators running in parallel, each reproducing reverberation according to the characteristics of an acoustic environment.

[0073] The environments can furthermore provide inputs to each other via so called portals. For example, as shown with respect to the example environment shown in Figure 2 there can be audio sources 210 (represented by Si 210i and S2 2102) located in Acoustic Environment AE2 205. The AE2 205 can be coupled via the portal or acoustic coupling AC1 207 to the acoustic environment AE1 203. A listener L 202 can furthermore move through the environment such that the listener can be located at a first position Pi 200i which is located within AE2205, then move to a second position P2 2OO2 which is located within AE1 203 and moving out of the environment into the outdoor 201 at a third position P32OO3.

[0074] The rendering of the audio is such that the listener when at Pi experiences reverberation based on AE2205 but when passing through the acoustic opening or portal into another acoustic environment AE1 203 then the audio sources Si 210i and S2 2102 should also be reverberated by the reverberator associated with the AE1 203.

[0075] If the audio sources from the neighboring environment AE2 are not reverberated in AE1 then the reverberated sound of AE2 may sound unrealistic. Consider, for example, a gunshot being fired in a relatively dry room (AE2) connected to highly reverberant room (AE1). If the reverberation is implemented without proper connection information between AE1 and AE2, then the gunshot sound is not reverberated in the highly reverberant AE1 even though from the physical perspective this would be clearly expected by the listener. This would work as expected if the connection information for acoustic portal AC1 is complete (i.e. with information that AE1 and AE2 are connected to AC1). Whilst this is possible to determine reverberation and therefore render a virtual reality (VR) scene, such as shown in Figure 2, where both the portal and acoustic environments are known during content creation it is not possible in augmented reality (AR) scene to perform rendering of reverberation with external sources (in other words a connected reverb between two rooms or acoustic environments connected via a content creator defined portal). This is because in an AR scene the scene is not completely defined during content creation as the acoustic environment corresponding to the physical space is not known beforehand (it will be known only during rendering) and as such the portal between the acoustic environment which comprises the audio sources and the physical acoustic environment is not fully defined.

[0076] For example, figure 3a shows a scenario where the two rooms or acoustic environments are connected via an acoustic portal (or portal). As such there is shown the (first) bitstream defined acoustic environment (BAE2) 305 within which is located the audio sources 210 (represented by Si 2101 and S2 2102) and the (second) LSDF defined acoustic environment (LAE1) 303 or physical environment within which the listener PL 200L is located. As is shown by Figure 3a the audio sources (located in acoustic environment BAE2305) should contribute via bitstream defined portal AC1 307 to the diffuse late reverberation in the acoustic environment LAE1 303. Consequently, the listener at position PL 200L should be able to perceive sources Si and S2 that are reverberated according to the acoustic environment parameters of LAE1.

[0077] In such a scenario, the portal defined in the bitstream (AC1) 307 has only one acoustic environment connection defined in the bitstream corresponding to the virtual acoustic environment (BAE) 305. The connection to the physical acoustic environment (LAE1) is unspecified in the bitstream (as represented by the ? in the Figure 3a schematic block view).

[0078] Consequently, the connection information for defining the acoustic portal is incomplete for the scene having two acoustic environments. This can result in a scenario such as shown in Figure 3b.

[0079] In this example where the listener is at position Pu 300L (within the bitstream defined acoustic environment) the audio sources Si 210i and S2 2102 are audible with immersive reverb in accordance with reverberation parameters of the acoustic environment BAEi 305 and the rendering of the audio sources and the application of reverberation can be implemented as the environment is purely within the bitstream defined environment. However, if the listener is at position PL 200L, the audio sources Si 210i and S2 2102 appear without immersive reverberation from listener’s current acoustic environment, in the physical listening space represented by LAE1. This results in an unnatural or implausible rendering for the audio sources Si 2101 and S2 2102. This therefore breaks an immersion effect as perceived by the listener and therefore results in poor subjective audio quality.

[0080] For some scenes, the implausibility or unnatural effect can be very significant. For example, if the listener is consuming the scene in a highly reverberant listening space such as a cathedral (for example, the PL is in a big hall of a cathedral).

[0081] The concept as discussed herein in further detail in the embodiments herein relates to reproduction of (late) reverberation in augmented reality (AR) scenes with multiple acoustic environments. In these embodiments there is described apparatus and methods configured to enable completion (or obtaining a complete definition) of acoustic portal connection information with the acoustic environments in the scene by associating a virtual scene acoustic environment specified in the bitstream with an acoustic environment corresponding to a physical space obtained during (or at the start of) the rendering to establish connection information between the virtual and physical acoustic environments.

[0082] This completion of the portal connection information (or the obtaining of the definition) with the physical and virtual acoustic environment enables a rendering of reverberation for sound sources external to an acoustic environment where there is at least one acoustic environment information available only during rendering.

[0083] In some embodiments this can be achieved by the following operations: obtaining virtual scene bitstream; determine presence of an Anchor element in the scene description payload, which indicates a part of the entire scene will be available during rendering (since it is an AR scene, and the listener space is known only during content consumption); If the anchor element is present, check for the presence of content creator defined portal with an extent (portalExtent) that is included within the Anchor element; determine a presence of an extent of the content creator defined portal within the Anchor element which indicates the content creator intent to associate the portal with acoustic environment obtained during rendering;

[0084] If the AR anchor obtained during rendering is within less than a predefined threshold distance (e.g., 1 .0 meter) from the center of the content creator defined portal, the content creator defined acoustic environment is associated with the rendering time obtained acoustic environment (e.g., physical space acoustic environment where the listener is present for consuming the content); and perform rendering of reverberation for sound sources external to an acoustic environment with full knowledge about the connections between the acoustic environments.

[0085] In some embodiments, the bitstream comprises information enabling the obtaining of the definition or completion of a portal connection with acoustic environments during content consumption or start of content consumption or initialization of the Tenderer.

[0086] Furthermore in some embodiments, the obtaining of the portal definition can be performed based at least partially on an user interaction.

[0087] In some embodiments, the portal connection information defining the portal between the acoustic environments is furthermore augmented by the Tenderer.

[0088] In implementing the embodiments described herein the coupling or the connection between the acoustic environment introduced from the LSDF file is therefore completed (or completely defined) with respect to the acoustic portals (in the scene). In such a manner the embodiments result in being able to use external source contributions for reverberation in the listener’s physical space. This will result in obtaining a key requirement for reproducing reverberation according to the listener’s current acoustic environment and achieving a good quality AR experience which is an important domain for 6DoF immersive audio in general and MPEG-I Immersive audio in particular. With respect to Figures 4a and 4b there is shown a schematic view of example apparatus suitable for implementing some embodiments. The example apparatus can be implemented within a Tenderer or playback apparatus.

[0089] The input to the apparatus comprises scene and reverberation parameters and furthermore acoustic portal information (or parameters) 400, listener space description file (LSDF) 422, audio signal 406 and listener pose parameter 402.

[0090] In some embodiments the input to the system of apparatus comprises scene and reverberation parameters and furthermore acoustic portal information (or parameters) 400. The scene and reverberation parameters in some embodiments can be obtained from a retrieved 6DoF rendering bitstream such as provided by a suitable bitstream. The scene and reverberation parameters in some embodiments are in the form of enclosing room geometry and acoustic parameters (for example reverberation time RT60, reverberation ratio as DSR or RDR). The scene and reverberation parameters in some embodiments can also comprise: the positions of audio elements (sound sources) in the environment; the positions of the enclosing room geometries (or Acoustic Environments) so that the method can determine in which acoustic environment the listener currently is based on the listener pose parameters 402; the positions and geometries of the portals (i.e. the acoustic couplings or openings in scene geometry) such that sound can pass between acoustic environments; and polynomial coefficients (or more generally model parameters) for calculating gain values for sources in connected acoustic environments (or elsewhere in the audio scene). The scene information can furthermore comprise acoustic portals which have only a single connected acoustic environment defined in the bitstream definition and the second connection for the acoustic environment not specified. In some embodiments, for AR scenes, the input parameters can also carry information regarding AR Anchor elements which provide listening space specific information to associate with the LSDF 422 (corresponding to the listener space) obtained during the AR scene consumption.

[0091] The LSDF 422 in some embodiments comprises similar information to the scene and reverberation parameters and furthermore acoustic portal information (or parameters) 400 with a key difference, that the LSDF 422 is received by the Tenderer only during rendering or more specifically during the initialization of the Tenderer. Furthermore, the LSDF file comprises at least one anchor element to enable association with the input parameter AR Anchors described above. In some embodiments the reverberation parameters are in the form of enclosing room geometry and acoustic parameters (reverberation time RT60, reverberation ratio as DSR or RDR).

[0092] The listener pose information 402 is based on the orientation and / or position of the listener or user of the playback apparatus.

[0093] The audio signal 406 which can be obtained from the retrieved audio data and which in some embodiments is provided by the suitable obtained bitstream.

[0094] As an output, the apparatus provides a reverberated audio signal 414 (e.g. a binauralized audio signal with head-related-transfer-function (HRTF) filtering for reproduction to headphones, or panned with Vector-Base Amplitude Panning (VBAP) for reproduction to loudspeakers).

[0095] In some embodiments the acoustic environment (AE) with acoustic portal linkage associator 411 is configured to receive the Scene, reverberation parameters, portal information from bitstream 400 and the Listener space description file (LSDF) 422 and information relating to the associations between the AEs.

[0096] This information 426 relating to the associations can be passed to the reverberation controller 401 .

[0097] The apparatus in some embodiments comprises a reverberator controller 401 , which is configured to receive the scene, reverberation parameters and portal information from the bitstream 400 and furthermore information 426 relating to the associations between the AEs and from these produce direct propagation values and delays 424 for sound sources which are outside acoustic environments but feed their energy to the acoustic environments via portals.

[0098] These direct propagation values and delays 424 information can change over time as portals open or close or sound sources move. In order to produce the direct propagation values and delays 424, the reverberator controller 401 is configured to employ the positions and geometries of portals, positions of sound sources, and polynomial coefficients obtained via the bitstream 400 and the LSDF 422 scene and reverberation parameters, and portal information.

[0099] In some embodiments, the reverberator output signal is fed as input to the reverberator connected with appropriate gains 428 via portals. Such feeding of diffuse energy from neighboring acoustic environments via portals adds further realism to the immersive reverb experienced by the listener. Such feeding of diffuse reverb energy is inhibited in case of incomplete connection information between the portals and acoustic environments (this is shown in the example shown in Figure 4b).

[0100] In some embodiments the apparatus comprises a reverberator configurator 403. The reverberator configurator 403 in some embodiments is configured to convert the reverberation parameters into reverberator parameters 404 which are parameters for the digital feedback delay network (FDN) reverberator (or more generally the reverberators 405).

[0101] In some embodiments the apparatus comprises reverberators 405. The reverberators 405 are configured to receive the direct propagation values and delays 424, audio signal 406 s£n(t) (where t is time) and reverberator parameters 304. The reverberators 405 in some embodiments are initialized and employed to reproduce reverberation according to the reverberator parameters 404. In some embodiments the each of the reverberators 405 is configured to reproduce the reverberation according to the characteristics (reverberation time and level) of an acoustic environment, where the corresponding reverberator parameters are derived from. In some embodiments, the reverberator parameters 404 are produced by an optimization or configuration routine on the reverberator controller 401 based on acoustic environment (reverberation) parameters.

[0102] In these embodiments the reverberators 405 are configured to reverberate the audio signal 406 based on the reverberator parameters 404 and direct propagation values and delays 424. The details of the reverberation processing are discussed in further details below.

[0103] The reverberator output audio signals srev r(j, t) 410 (where j is the output audio channel index and r the reverberator index) are output from the reverberators 405.

[0104] In some embodiments there are several reverberators, each of which produce several output audio signals.

[0105] In some embodiments the apparatus comprises a reverberator output signals spatializer 407 which is configured to receive the reverberator output audio signals 410 and produce a reverberated audio signal 414 suitable for reproduction via headphones or via loudspeakers. The reverberator output signals spatializer 407 is also configured to receive reverberator output channel positions 412 from a reverberator output signals spatialization controller 409. The reverberator output channel positions 412 in some embodiments is configured to indicate the Cartesian coordinates which are to be used when rendering each of the signals in srev r(j, t). In alternative embodiments other representations such as polar coordinates can be used.

[0106] The reverberator output signals spatializer 407 can be configured to render each reverberator into a desired output format such as binaural and then sum the signals to produce the output reverberated audio signal 414. For binaural reproduction the reverberator output signals spatializer 407 can be configured to use HRTF filtering to render the reverberator output audio signals 410 in their desired positions indicated by reverberator output channel positions 412.

[0107] In such a manner this reverberation in the reverberated audio signals 414 is based on based on the via the bitstream 400 and the LSDF 422 scene and reverberation parameters, and portal information and considers listener pose parameters 402.

[0108] The AE with acoustic portal linkage associator 411 is configured to determine or obtain the complete couplings between the acoustic environments. In other words to ‘completely’ define the acoustic portal or portals linking acoustic environments where they are not completely defined with respect to the bitstream (in other words obtain the portal parameters not determined by the content creator in the scene, reverberation and portal parameters from the bitstream).

[0109] For example, where it is determined that there is a scene which has one acoustic environment connection to a portal specified in the bitstream, but the second acoustic environment is not specified, such portal connections need to be completed for AR scenes, where the LSDF file may introduce an additional acoustic environment.

[0110] In such a scenario, the associator is configured to complete (or obtain) the portal connection information based on the bitstream information and the LSDF file obtained during the AR scene consumption.

[0111] The apparatus shown in Figures 4a and 4b and flow chart in Figure 5 can be used by an encoder to determine if additional bitstream information should be inserted to enable the Tenderer to perform complete the association information for an acoustic portal with one or more acoustic environments.

[0112] In some embodiments, there may not be any insertion of explicit bitstream signalling to facilitate association of missing connection information for an acoustic portal. The connection information is expected to be completed by the Tenderer during information available during rendering.

[0113] With respect to Figure 5 is shown a flow diagram of the operation of the associator 411 according to some embodiments.

[0114] Thus, in some embodiments, there is an operation of obtaining or receiving the scene, portals and reverberation parameter information from the bitstream as shown by step 501 in Figure 5.

[0115] Then from the portal payload, there is the operation of obtaining the list of explicitly defined portals in the scene as shown by step 503 in Figure 5.

[0116] Subsequently, for each portal, determine if at least a first connected acoustic environment is specified or defined as shown by step 505 in Figure 5.

[0117] Furthermore for portals with at least a first connected acoustic environment, determine if the second connected acoustic environment is specified as shown by step 507 in Figure 5.

[0118] Then for each portal, if the second connected acoustic environment is not specified, such portals can be candidates for subsequent connection with another acoustic environment by the Tenderer during content consumption as shown by step 509 in Figure 5.

[0119] This can for example be implemented as, for each portal, If the second acoustic environment is undefined, determine if the portal extent is within the AR anchor element as shown by step 511 in Figure 5.

[0120] Additionally there can be, for each portal, if the portal extent is within the AR anchor element, the second acoustic environment will be determined during rendering or during initialization for AR scenes 513.

[0121] In some embodiments, additional information or cues can be derived from the bitstream information or user interaction.

[0122] In some embodiments the association operations can obtain implicit association of portal connections between bitstream defined and LSDF file defined acoustic environments. In these example embodiments an implicit association approach in the scope of MPEG-I Immersive audio standard specification for implementing association between the AR LSDF file provided acoustic environment with a portal in the bitstream specified scene description.

[0123] With respect to figure 6 is shown operations which for the obtaining or determining of a connection between acoustic environment defined in the LSDF file with the portal define in the bitstream. These can, for example, be described by the following.

[0124] The initial operation is one of selecting the AR scene for rendering as shown by 601 in Figure 6

[0125] In some embodiments there is the obtaining of AR scene information via scene specific bitstream as shown by 603 in Figure 6.

[0126] Then is shown the obtaining of virtual scene information from the scene specific bitstream as shown by 605 in Figure 6.

[0127] Following this is obtaining portal payload from the scene specific bitstream as shown by 607 in Figure 6.

[0128] An obtaining or determining if one or more portals in the bitstream is connected with only one acoustic environment is performed as shown by 609 in Figure 6.

[0129] For each portal linked with only one connected acoustic environment defined in the bitstream and a portal extent within AR Anchor element in the scene specific bitstream information, the second acoustic environment is judged to be determined for AR scene rendering as shown by 611 in Figure 6.

[0130] Subsequently, during the start of the AR scene consumption, the Tenderer receives the LSDF file to initialize AR scene rendering as shown by 613 in Figure 6.

[0131] Additionally there is the operation of obtaining any anchor and acoustic environment representing the listener space from the LSDF file as shown by 615 in Figure 6.

[0132] There is then a determining whether there is a match between an Anchor ID in the LSDF file with the AR Anchor in the bitstream. If there is a match, perform a proximity check between the center of the portal defined in the scene specific bitstream and the corresponding Anchor position in the LSDF file as shown by 617 in Figure 6.

[0133] Following this there is an associating of the LSDF file provided acoustic environment with the portal as the second connection of the relevant portal as shown by 619 in Figure 6.

[0134] Then it is possible to perform rendering of the scene with full connection information for the portal with portal extent in the Anchor element as shown by 621 in Figure 6.

[0135] In some embodiments, after the portal connections are determined the following operations can be performed: obtain the reverberation or reverberator parameters (400 or 404) for the connected AEs; check or determine if some of the parameters are equal for the two connected AEs and if so modify reverberation or reverberator parameters of one of the AEs so that they are different.

[0136] In such a manner there are no delay lines in the reverberators that share the same delay line length (which would produce a poor audio quality). In some embodiments the implementation delay line lengths are obtained by calculating or determining lengths based on room dimensions and then mapping the lengths to closest prime numbers.

[0137] In some embodiments this can be implemented by one or both of: modifying reverberation parameters 400: This can be done by checking if connected AEs have equal room dimensions, and if they do, multiply the dimensions of one the AEs by a factor, for example 1.1 for reverb parameter calculation. Then the reverberator parameters can be determined or generated again for the AE. modifying reverberator parameters 404: This can be done by checking if there are equal delay line lengths (these are prime numbers). If so, for one of the AEs, for the offending delay line length, find the second closest prime number (that is not already used by any of the delay lines of either reverberator).

[0138] In some embodiments there is an explicit association of portal connections between bitstream defined and LSDF file defined acoustic environments or any other acoustic environments. Thus for each portal without the second connected acoustic environment portal, a determination of the need for a second acoustic environment connection can also be made more explicitly for scenarios where the portal is defined without an extent.

[0139] Additionally, in some embodiments the portal extent can be specified outside the Anchor element in the bitstream. For example additional information can be employed by the Tenderer to determine whether to associate a second connected acoustic environment for this portal.

[0140] For example, in some embodiments, the portal data structure can carry information to indicate that even though only one acoustic environment is specified as connected to an acoustic portal in the bitstream, the portal expects a second acoustic environment during AR consumption of the scene, VR consumption of the scene, etc.

[0141] In some embodiments there can be other information or indications to indicate that a second acoustic environment may be permitted only if it is a default acoustic environment (in other words diffuse late reverberation effect that is produced outside the acoustic environment regions in the scene). These different scenarios and more can be indicated as a connection type parameter introduced in the bitstream.

[0142] In some different embodiments, both the first and the second acoustic environment connection to the portal are defined from the LSDF file in an AR scene, if the LSDF file carries definition for two or more acoustic environments corresponding to a physical listening space. This may be of particular interest for scenes where two physical rooms are connected only via a virtual acoustic portal.

[0143] In some further embodiments, with explicit indication of association of acoustic environments with portals having partial connection information (e.g. only one acoustic environment specified in the bitstream), the association can be performed without presence of portal extent within the AR Anchor element in the bitstream. The connection of physical acoustic environments can be implemented with an acoustic portal already having two acoustic environments specified in the bitstream, although having explicit indication that the physical acoustic environment defined in the LSDF file, if LSDF file is with necessary information is available, shall have precedence of a virtual acoustic environment defined in the bitstream. payloadPortal ( ) { unsigned int(8) numPortals; if (numPortals ) >0 { unsigned int(l) isExplicitPortalMode;

[0144] } f or ( i=0 ; i<numPortals ; i++ ) { unsigned int(8) portalld; unsigned int(l) hasExtent; if (hasExtent) { portalExtent Id;

[0145] }

[0146] } if ( isExplicitPortalMode ) { unsigned int(l) isConnectedToAE; if (isConnectedToAE) { unsigned int(8) portalEnvl; unsigned int (8) isConnectedToAE; if ( isConnectedToSecondAE ) { unsigned int (8) portalEnv2;

[0147] }

[0148] } unsigned int(l) hasMaterial; if (hasMaterial) { unsigned int (8) portalMaterialld;

[0149] } unsigned int(l) portalNormal ; if ( explicitPortalProperties ) { portalCenterPosStruct ( ) ; unsigned int (16) equivalentPortalWidth; unsigned int (16) equivalentPortalHeight ; unsigned int (16) equivalentPortalDepth;

[0150] } else { unsigned int (8) portalParentEnvId = GetID() ; }

[0151] In some embodiments the Explicit definitions in the portal payload bitstream to enable linking of acoustic environments with a portal during rendering or content consumption can be, for example: payloadPortal ( ) { unsigned int(8) numPortals; if (numPortals ) >0 { unsigned int(l) isExplicitPortalMode;

[0152] } f or ( i=0 ; i<numPortals ; i++ ) { unsigned int (8) portalld; unsigned int(l) hasExtent; if (hasExtent) { portalExtent Id;

[0153] }

[0154] } if ( isExplicitPortalMode ) { unsigned int(l) isConnectedToAE; if (isConnectedToAE) { unsigned int(8) portalEnvl; unsigned int (8) isConnectedToAE; unsigned int (8) revContType; if ( IsConnectedToSecondAE ) { unsigned int(4) connectionType ; if ( connectionType==l ) unsigned int (8) revContType; unsigned int (8) portalEnv2; if ( connectionType==2 ) unsigned int (8) revContType; unsigned int(l) def aultAEIsPortalEnv2 ; if ( connectionType==3 ) unsigned int (8) revContType; unsigned int(l) AREnvIsPortalEnv2 ; if ( connectionType==4 ) unsigned int (8) revContType; unsigned int (8) portalEnv2;

[0155] }

[0156] } unsigned int(l) hasMaterial; if (hasMaterial) { unsigned int (8) portalMaterialld;

[0157] } unsigned int(l) portalNormal ; if ( explicitPortalProperties ) { portalCenterPosStruct ( ) ; unsigned int (16) equivalentPortalWidth; unsigned int (16) equivalentPortalHeight ; unsigned int (16) equivalentPortalDepth;

[0158] } else { unsigned int (8) portalParentEnvId = GetID() ; } }

[0159] With respect to Figure 7 is shown an example effect of implementing some embodiments as described above. In some embodiments the example shows a listener is in a highly reverberant physical space such as the main hall of a cathedral. In case the listener is consuming an AR scene in such an environment LAEi 303, any audio source is expected to become highly reverberant. Implementing the embodiments as described above can therefore result in a rendered output where the audio sources in another acoustic environment BAE2 305 will become highly reverberant (e.g., due to direct propagation component or diffuse component contribution of audio sources in the neighboring acoustic environment connected via an acoustic coupling such as AC1). This is possible because the connection information of the portal in the bitstream is augmented based on these embodiments. In contrast, a system without implementing these embodiments would have rendered the audio sources in another acoustic environment without the expected high reverberation when the listener is consuming the AR scene in the big cathedral hall, which would be quite implausible and break immersion.

[0160] With respect to Figure 8 is shown schematically an example system where the embodiments are implemented by an encoder 1901 which writes data into a bitstream 1921 and transmits that for a decoder / renderer 1941 , which decodes the bitstream, performs reverberator processing according to the embodiments and outputs audio for headphone listening.

[0161] Figure 8 therefore shows apparatus, and specifically the encoder 1901 and renderer device 1941 , which is suitable for implementing the above embodiments.

[0162] The encoder or server 1901 in some embodiments can be performed on content creator computers and / or network server computers. The encoder 1901 can generate the bitstream 1921 which is made available for downloading or streaming (or storing). The decoder / renderer 1941 which may be implemented as a playback device and which can be a mobile device, personal computer, sound bar, tablet computer, car media system, home HiFi or theatre system, head mounted display for AR or VR, smart watch, or any suitable system for audio consumption.

[0163] The encoder 1901 is configured to receive the virtual scene description 1900 and the audio signals 1904. The virtual scene description 1900 can be provided in the MPEG-I Encoder Input Format (EIF) or in another suitable format. Generally, the virtual scene description contains an acoustically relevant description of the contents of the virtual scene, and contains, for example, the scene geometry as a mesh or voxel, acoustic materials, acoustic environments with reverberation parameters, positions of sound sources, and other audio element related parameters such as whether reverberation is to be rendered for an audio element or not.

[0164] In some embodiments the encoder 1901 comprises a scene and portal connection parameter obtainer 1915 configured to obtain the virtual scene description and portal parameters.

[0165] Furthermore the encoder 1901 can comprise a Portal payload for coupling with acoustic environments via bitstream generator 1917 which is configured to generate the portal payload.

[0166] Furthermore the encoder 1901 can comprise in some embodiments a reverberation parameter obtainer 1911 which is configured to obtain the virtual scene description 1900 and generate or obtain suitable reverberation parameters.

[0167] Furthermore, in some embodiments, the encoder 1901 comprises a reverberation payload encoder 1913 configured to obtain the determined or obtained reverberation parameters and generate a suitable encoded payload.

[0168] The encoder 1901 further comprises a MPEG-H 3D audio encoder 1914 configured to obtain the audio signals 1904 and MPEG-H encode them and pass them to a bitstream encoder 1915. The input audio signals may also be coded with any other suitable format such as EVS, IVAS, AAC, etc.

[0169] The encoder 1901 furthermore in some embodiments comprises a bitstream encoder 1915 which is configured to receive the output of the reverberation payload encoder 1913 and the encoded audio signals from the MPEG-H encoder 1914 and the scene and portal connection payload and generate the bitstream 1921 which can be passed to the bitstream decoder 1951. The bitstream 1921 in some embodiments can be streamed to end-user devices or made available for download or stored.

[0170] The decoder / renderer 1941 in some embodiments is configured to receive or otherwise obtain the bitstream 1921 , and furthermore can be configured to receive or otherwise obtain the listening space description from a listening space description generator 1971 (which can in some embodiments be in a listening space description format - LSDF), which defines the acoustic properties of the listening space within which the user or listener is operating in. Additionally in some embodiments the playback device is configured to obtain, for example from the head mounted device (HMD), listener orientation or position information. These can for example be generated by sensors within the HMD or from sensors in the environment sensing the orientation or position of the listener.

[0171] In some embodiments the decoder / renderer 1941 comprises a bitstream decoder 1951 which is configured to regenerate the scene, portal and reverberation information and pass it to a scene, portal and reverberation payload decoder 1953, and obtain MPEG-H 3D audio packets which are passed to the MPEG-H 3D audio decoder 1954, and audio element parameters such as sound sources positions for direct sound processing.

[0172] The decoder / renderer 1941 further can comprise a scene, portal and reverberation payload decoder 1953 configured to obtain the encoded scene, portal and reverberation parameters and decode these in an opposite or inverse operation to the reverberation payload encoder 1913 and scene and portal connection payload generator 1917.

[0173] In some embodiments the decoder / renderer 1941 comprises a head pose generator 1957 which is configured to receive information from a head mounted device or similar and generates head pose information or parameters which can be passed to the reverberator output signal spatializer 1962 and HRTF processor 1963.

[0174] The decoder / renderer 1941 , in some embodiments, comprises a reverberator controller 1955 and configurator 1956 which is configured to obtain the determined scene, portal and reverberation parameters and generate the parameters which can be passed to the (FDN) reverberators 1961 in a manner as described earlier. Furthermore, the decoder Tenderer can also have FDN reverberator output feeding the reverberators 1968 that are connected to the other acoustic environments via portals in scene formed by fusion of virtual and physical scene.

[0175] The decoder / renderer 1941 in some embodiments comprises a MPEG-H 3D audio decoder 1954 which is configured to decode the audio signals and pass them to the (FDN) reverberator 1911 and direct sound processor 1965.

[0176] The decoder / renderer 1941 furthermore comprises the portal with AE coupler 1958 which is configured to implement the functions of the AE with Acoustic portal linkage associator 411 as described earlier.

[0177] The decoder / renderer 1941 furthermore comprises the (FDN) reverberator 1961 initialized by the reverberator controller 1955 and reverberator configurator 1956 and configured to implement a suitable reverberation of the audio signals.

[0178] The output of the (FDN) reverberator 1955 is configured to output to a reverberator output signals spatializer 1962.

[0179] Additionally the decoder / renderer 1941 comprises a direct sound processor 1965 which is configured to receive the decoded audio signals and configured to implement any direct sound processing such as air absorption and distance-gain attenuation and which can be passed to a HRTF processor 1963.

[0180] The HRTF processor 1963 can be configured to receive the output of the direct sound processor 1965 and generate processed audio signals associated with the processed direct audio components to the binaural signal combiner 1967.

[0181] The binaural signal combiner 1967 is configured to combine the direct and reverberant parts to generate a suitable output (for example for headphone reproduction).

[0182] The output can be passed to the head mounted device.

[0183] The playback device can be implemented in different form factors depending on the application. In some embodiments the playback device is equipped with its own listener position tracking apparatus or receives the listener position information from an external apparatus. The playback device can in some embodiments be also equipped with headphone connector to deliver output of the rendered binaural audio to the headphones.

[0184] With respect to Figure 9 an example electronic device which may be used as any of the apparatus parts of the system as described above. The device may be any suitable electronics device or apparatus. For example in some embodiments the device 2000 is a mobile device, user equipment, tablet computer, computer, audio playback apparatus, etc. The device may for example be configured to implement the encoder or the Tenderer or any functional block as described above.

[0185] In some embodiments the device 2000 comprises at least one processor or central processing unit 2007. The processor 2007 can be configured to execute various program codes such as the methods such as described herein.

[0186] In some embodiments the device 2000 comprises a memory 2011 . In some embodiments the at least one processor 2007 is coupled to the memory 2011 . The memory 2011 can be any suitable storage means. In some embodiments the memory 2011 comprises a program code section for storing program codes implementable upon the processor 2007. Furthermore in some embodiments the memory 2011 can further comprise a stored data section for storing data, for example data that has been processed or to be processed in accordance with the embodiments as described herein. The implemented program code stored within the program code section and the data stored within the stored data section can be retrieved by the processor 2007 whenever needed via the memory-processor coupling.

[0187] In some embodiments the device 2000 comprises a user interface 2005. The user interface 2005 can be coupled in some embodiments to the processor 2007. In some embodiments the processor 2007 can control the operation of the user interface 2005 and receive inputs from the user interface 2005. In some embodiments the user interface 2005 can enable a user to input commands to the device 2000, for example via a keypad. In some embodiments the user interface 2005 can enable the user to obtain information from the device 2000. For example the user interface 2005 may comprise a display configured to display information from the device 2000 to the user. The user interface 2005 can in some embodiments comprise a touch screen or touch interface capable of both enabling information to be entered to the device 2000 and further displaying information to the user of the device 2000. In some embodiments the user interface 2005 may be the user interface for communicating.

[0188] In some embodiments the device 2000 comprises an input / output port 2009. The input / output port 2009 in some embodiments comprises a transceiver. The transceiver in such embodiments can be coupled to the processor 2007 and configured to enable a communication with other apparatus or electronic devices, for example via a wireless communications network. The transceiver or any suitable transceiver or transmitter and / or receiver means can in some embodiments be configured to communicate with other electronic devices or apparatus via a wire or wired coupling.

[0189] The transceiver can communicate with further apparatus by any suitable known communications protocol. For example in some embodiments the transceiver can use a suitable universal mobile telecommunications system (UMTS) protocol, a wireless local area network (WLAN) protocol such as for example IEEE 802. X, a suitable short-range radio frequency communication protocol such as Bluetooth, or infrared data communication pathway (IRDA).

[0190] The input / output port 2009 may be configured to receive the signals.

[0191] In some embodiments the device 2000 may be employed as at least part of the Tenderer. The input / output port 2009 may be coupled to headphones (which may be a headtracked or a non-tracked headphones) or similar.

[0192] In general, the various embodiments of the invention may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the invention is not limited thereto. While various aspects of the invention may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof. The embodiments of this invention may be implemented by computer software executable by a data processor of the mobile device, such as in the processor entity, or by hardware, or by a combination of software and hardware. Further in this regard it should be noted that any blocks of the logic flow as in the Figures may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on such physical media as memory chips, or memory blocks implemented within the processor, magnetic media such as hard disk or floppy disks, and optical media such as for example DVD and the data variants thereof, CD.

[0193] The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processors may be of any type suitable to the local technical environment, and may include one or more of general-purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASIC), gate level circuits and processors based on multi-core processor architecture, as non-limiting examples.

[0194] Embodiments of the inventions may be practiced in various components such as integrated circuit modules. The design of integrated circuits is by and large a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

[0195] Programs, such as those provided by Synopsys, Inc. of Mountain View, California and Cadence Design, of San Jose, California automatically route conductors and locate components on a semiconductor chip using well established rules of design as well as libraries of pre-stored design modules. Once the design for a semiconductor circuit has been completed, the resultant design, in a standardized electronic format (e.g., Opus, GDSII, or the like) may be transmitted to a semiconductor fabrication facility or "fab" for fabrication.

[0196] As used in this application, the term “circuitry” may refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and

[0197] (b) combinations of hardware circuits and software, such as (as applicable):

[0198] (i) a combination of analog and / or digital hardware circuit(s) with software / firmware and

[0199] (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

[0200] I hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

[0201] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0202] The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e. , tangible, not a signal ) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM).

[0203] As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements

[0204] The foregoing description has provided by way of exemplary and nonlimiting examples a full and informative description of the exemplary embodiment of this invention. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings of this invention will still fall within the scope of this invention as defined in the appended claims.

Claims

CLAIMS:1 . A method for an apparatus for spatial rendering of reverberation, the method comprising: obtaining a bitstream for a virtual scene, the bitstream for a virtual scene comprising at least one reverberation parameter associated with a first acoustic environment, and at least one acoustic space connection information associated with the first acoustic environment; obtaining at least one second acoustic environment and associated position data; associating the second acoustic environment with the first acoustic environment based on at least one of the associated position data and the at least one acoustic space connection information; determining at least first reverberation processing based on the association between the second acoustic environment and the first acoustic environment; and generating a reverberated audio signal based on the at least one reverberation parameter and the at least first reverberation processing applied to at least one sound source audio signal.

2. The method as claimed in claim 1 , wherein the at least one second acoustic environment is listener space acoustic information and the associated position data comprises anchor position data.

3. The method as claimed in claim 1 , wherein the at least one acoustic space connection information is for indicating at least part of the first acoustic environment is available for being coupled to at least one further acoustic environment.

4. The method as claimed in any of claim 2, wherein the at least one acoustic space connection information associated with the first acoustic environment defines at least one portal associated with the first acoustic environment.

5. The method as claimed in claim 4, wherein associating the second acoustic environment with the first acoustic environment based on the associated positiondata and the at least one acoustic space connection information comprises determining the at least one portal is defined with respect to the first acoustic environment.

6. The method as claimed in claim 5, wherein the listener space information associated with a listener space acoustic environment comprises an anchor element defined by an anchor identifier and / or anchor position.

7. The method as claimed in claim 6, wherein associating the second acoustic environment with the first acoustic environment based on the listener space information and the at least one acoustic space connection comprises: determining the at least one portal extent is within the anchor element identified by the anchor identifier; and determining portal connection information between the second acoustic environment and the first acoustic environment based on the listener space information and the at least one acoustic space connection information.

8. The method as claimed in claim 7, wherein determining the portal extent is within the anchor element identified by the at least one anchor identifier further comprises determining the at least one portal is within a proximity distance threshold of the extent of the anchor element identified by the at least one anchor identifier.

9. The method as claimed in claim 1 , wherein the at least one reverberation parameter associated with a first acoustic environment comprises one or more of: reverberation time values; reverberation ratio values; dimension values associated with the at least first acoustic environment.

10. The method as claimed in claim 1 , wherein determining the at least first reverberation processing based on the association between the second acoustic environment with the first acoustic environment comprises determining an audio source within the first acoustic environment as an external source for the secondacoustic environment and inputting an audio signal from the external source to at least one second acoustic environment reverberator controlled by at least one reverberation parameter.

11. The method as claimed in claim 1 , wherein determining the at least first reverberation processing based on the association between the second acoustic environment with the first acoustic environment comprises determining leaking at least one reverberated audio signal from the first acoustic environment to the to at least one second acoustic environment reverberator controlled by at least one reverberation parameter.

12. The method as claimed in claim 1 , further comprising determining a second reverberation parameter associated with the second acoustic environment and modifying the second reverberation parameter to obtain a modified second acoustic parameter such that modified second acoustic parameter is not substantially similar to the first acoustic parameter.

13. An apparatus for spatial rendering of reverberation, the apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the system at least to perform: obtaining a bitstream for a virtual scene, the bitstream for a virtual scene comprising at least one reverberation parameter associated with a first acoustic environment, and at least one acoustic space connection information associated with the first acoustic environment; obtaining at least one second acoustic environment and associated position data; associating the second acoustic environment with the first acoustic environment based on at least one of the associated position data and the at least one acoustic space connection information; determining at least first reverberation processing based on the association between the second acoustic environment and the first acoustic environment; andgenerating a reverberated audio signal based on the at least one reverberation parameter and the at least first reverberation processing applied to at least one sound source audio signal.

14. The apparatus as claimed in claim 13, wherein the at least one second acoustic environment is listener space acoustic information and the associated position data comprises anchor position data.

15. The apparatus as claimed in claim 13, wherein the at least one acoustic space connection information is for indicating at least part of the first acoustic environment is available for being coupled to at least one further acoustic environment.

16. The apparatus as claimed in any of claim 14, wherein the at least one acoustic space connection information associated with the first acoustic environment defines at least one portal associated with the first acoustic environment.

17. The apparatus as claimed in claim 16, caused to perform associating the second acoustic environment with the first acoustic environment based on the associated position data and the at least one acoustic space connection information is further caused to perform determining the at least one portal is defined with respect to the first acoustic environment.

18. The apparatus as claimed in claim 17, wherein the listener space information associated with a listener space acoustic environment comprises an anchor element defined by an anchor identifier and / or anchor position.

19. The apparatus as claimed in claim 18, caused to perform associating the second acoustic environment with the first acoustic environment based on the listener space information and the at least one acoustic space connection is further caused to perform:determining the at least one portal extent is within the anchor element identified by the anchor identifier; and determining portal connection information between the second acoustic environment and the first acoustic environment based on the listener space information and the at least one acoustic space connection information.

20. The apparatus as claimed in claim 19, caused to perform determining the portal extent is within the anchor element identified by the at least one anchor identifier is further caused to perform determining the at least one portal is within a proximity distance threshold of the extent of the anchor element identified by the at least one anchor identifier.21 . An apparatus for spatial rendering of reverberation, the apparatus comprising means configured to: obtain a bitstream for a virtual scene, the bitstream for a virtual scene comprising at least one reverberation parameter associated with a first acoustic environment, and at least one acoustic space connection information associated with the first acoustic environment; obtain at least one second acoustic environment and associated position data; associate the second acoustic environment with the first acoustic environment based on at least one of the associated position data and the at least one acoustic space connection information; determine at least first reverberation processing based on the association between the second acoustic environment and the first acoustic environment; and generate a reverberated audio signal based on the at least one reverberation parameter and the at least first reverberation processing applied to at least one sound source audio signal.

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