Binaural dialogue improvement

Abstract

To provide methods and systems for efficient estimation of dialogue components for audio signals having stereophonic components referred to as immersive audio content.SOLUTION: A binaural dialogue estimator 52 receives a first audio signal presentation 51, and a set of dialogue estimation parameters 54 to enable estimation of dialogue components from the first audio signal presentation, applies the set of dialogue estimation parameters to the first audio signal presentation, and forms a dialogue presentation 53 of the dialogue components. The dialogue presentation is combined with a second audio signal presentation 56 to form a dialogue-enhanced (DE) audio signal presentation for reproduction on a second audio reproduction system, where at least one of the first and second audio signal presentations is a binaural audio signal presentation.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 62 / 288,590, filed Jan. 29, 2016, and European Patent Application No. 16153468.0, filed Jan. 29, 2016, the contents of both applications being incorporated herein by reference in their entireties.

[0002] FIELD OF THEINVENTION The present invention relates to the field of audio signal processing, and discloses a method and system for efficient estimation of the dialogue component, in particular for audio signals with a spatialized component, sometimes referred to as immersive audio content. [Background technology]

[0003] Any discussion of background art throughout this specification should not be taken in any way as an admission that such art is commonly known or part of the general common general knowledge in the art.

[0004] Audio content creation, encoding, distribution and playback are traditionally performed in channel-based formats, i.e., one specific target playback system is envisioned throughout the content ecosystem. Examples of such target playback system audio formats are mono, stereo, 5.1, 7.1, etc., and these formats are referred to as different presentations of the original content. The above presentations are typically played through loudspeakers, with a notable exception being stereo presentations, which are often also played directly through headphones.

[0005] One particular presentation is a binaural presentation, typically targeted for playback over headphones. A binaural presentation is characterized by a two-channel signal, each signal representing the content perceived at or near the left and right eardrums, respectively. A binaural presentation can be played back directly through loudspeakers, but preferably the binaural presentation is transformed using crosstalk cancellation techniques into a presentation suitable for playback through loudspeakers.

[0006] Various audio reproduction systems have been introduced above, such as loudspeakers and headphones in various configurations, e.g., stereo, 5.1, 7.1. From the above examples, it will be understood that the presentation of the original content has a natural, intended, associated audio reproduction system, but can of course also be reproduced on different audio reproduction systems.

[0007] When content is played on a playback system different from the one for which it was intended, a downmix or upmix process can be applied. For example, 5.1 content can be played on a stereo playback system by using a specific downmix formula. Another example is the playback of stereo encoded content on a 7.1 speaker setup, which may involve a so-called upmix process, which may or may not be guided by information present in the stereo signal. One system that can upmix is ​​Dolby Pro Logic from Dolby Laboratories (Roger Dressler, "Dolby Pro Logic Surround Decoder, Principles of Operation", www.Dolby.com).

[0008] An alternative audio format system is the Audio Object Format, such as that provided by the Dolby Atmos system. In this type of format, objects or components are defined as having a specific position around the listener. The position may vary over time. Audio content in this format is sometimes referred to as immersive audio content. Note that within the context of this application, the Audio Object Format is not considered a presentation as such, but rather a format of the original content that is rendered into one or more presentations at an encoder. After rendering, the presentation is encoded and transmitted to a decoder.

[0009] When multi-channel and object-based content is converted to a binaural presentation as described above, the acoustic scene consisting of loudspeakers and objects at specific positions is simulated by head-related impulse responses (HRIRs) or binaural room impulse responses (BRIRs), which simulate the acoustic paths from each loudspeaker / object to the eardrum in an anechoic or reverberant (simulated) environment, respectively. In particular, the audio signal can be convolved with the HRIRs or BRIRs to recover the interaural level difference (ILD), interaural time difference (ITD) and spectral cues, which allow the listener to discern the location of each individual loudspeaker / object. The simulation of the acoustic environment (reverberation) also helps to achieve the perceived distance. Figure 1 shows the two object or channel signals x i1 shows a schematic overview of the processing flow for rendering 10, 11 for processing by four HRIRs, e.g. 14. The HRIR outputs are then summed 15, 16 for the respective channel signals to generate a headphone and speaker output for playback to a listener via headphones 18. The basic principles of HRIRs are explained for example in [1]. [Non-Patent Document 1] Wightman, Frederic L., and Doris J. Kistler. "Sound localization." Human psychophysics. Springer New York, 1993. 155-192 The HRIR / BRIR convolution approach has several drawbacks. One of them is the significant amount of convolution processing required for headphone playback. The HRIR or BRIR convolution needs to be applied separately for every input object or channel, so the computational complexity typically grows linearly with the number of channels or objects. Because headphones are often used in conjunction with battery-powered portable devices, high computational complexity is undesirable as it can significantly shorten battery life. Furthermore, with the introduction of object-based audio content, which may contain, for example, more than 100 simultaneously active objects, the computational complexity of HRIR convolution can become substantially higher than for traditional channel-based content.

[0010] To this end, co-pending, unpublished U.S. Provisional Patent Application No. 62 / 209,735, filed August 25, 2015, describes a dual-ended approach to presentation transformation that can be used to efficiently transmit and decode immersive audio for headphones. By splitting the rendering process between the encoder and decoder, rather than relying solely on the decoder to render all objects, coding efficiency and reduced decoding complexity are achieved.

[0011] A piece of content that is associated with a particular spatial location during generation is called an audio component. The spatial location can be a point or a distributed location in space. Audio components can be thought of as all the individual audio sources that a sound artist mixes into a soundtrack, i.e., spatially positioned. Typically, a content meaning (e.g., dialogue) is assigned to the component of interest, thus defining the goal of processing (e.g., dialogue enhancement). Note that audio components generated during content generation typically exist throughout the processing chain, from the original content to the various presentations. For example, in an object format, there may be dialogue objects with associated spatial locations. In a stereo presentation, there may be dialogue components spatially positioned in the horizontal plane.

[0012] In some applications, it is desirable to extract dialogue components in an audio signal, for example to highlight or amplify such components. The goal of dialogue enhancement (DE) may be to modify the speech parts of the content, including a mixture of speech and background audio, so that the speech becomes more audible and / or less fatiguing to the end user. Another application of DE is to attenuate dialogue that is perceived as annoying by the end user, for example. There are two basic classes of DE methods: encoder-side and decoder-side. Decoder-side DE (called single-ended) operates only on the decoded parameters and signals that reconstruct the unenhanced audio, i.e., there is no dedicated side information for DE in the bitstream. In encoder-side DE (called dual-ended), dedicated side information that can be used to perform DE in the decoder is computed in the encoder and inserted into the bitstream.

[0013] Figure 2 shows an example of dual-ended dialogue enhancement in a normal stereo example, where dedicated parameters 21 are calculated in an encoder 20 that allow for the extraction of dialogue 22 from an unenhanced stereo signal 23 decoded in a decoder 24. The extracted dialogue is level modified, e.g. boosted 25 (by an amount partly controlled by the end user), and added to the unenhanced output 23 to form the final output 26. The dedicated parameters 21 can be blindly extracted from the unenhanced audio 27, or the parameter calculation can make use of a separately provided dialogue signal 28.

[0014] Another approach is described in US Pat. No. 6,399,436. Here, the bitstream to the decoder contains an object downmix signal (e.g. stereo presentation), object parameters enabling reconstruction of the audio objects, and object-based metadata allowing manipulation of the reconstructed audio objects. As shown in FIG. 10 of US Pat. No. 6,399,436, the manipulation may include amplification of speech-related objects. Thus, this approach requires reconstruction of the original audio objects at the decoder side, which is typically computationally intensive. [Patent Document 1] It is generally desirable to provide efficient dialogue estimation also in a binaural context. Summary of the Invention [Problem to be solved by the invention]

[0015] It is an object of the present invention to provide efficient dialogue enhancement in a binaural context, i.e. when at least one of the audio presentations from which the dialogue component(s) is / are extracted or to which the extracted dialogue is added is a binaural representation (reverberant or anechoic). [Means for solving the problem]

[0016] According to a first aspect of the present invention, there is provided a method for dialogue enhancing audio content having one or more audio components, each component associated with a spatial location, the method comprising: providing a first audio signal presentation of the audio components intended for playback on a first audio reproduction system, providing a second audio signal presentation of the audio components intended for playback on a second audio reproduction system, receiving a set of dialogue estimation parameters configured to enable estimation of a dialogue component from the first audio signal presentation, applying the set of dialogue estimation parameters to the first audio signal presentation to form a dialogue presentation of the dialogue component, and combining the dialogue presentation with the second audio signal presentation to form a dialogue enhanced audio signal presentation for playback on the second audio reproduction system, wherein at least one of the first and second audio signal presentations is a binaural audio signal presentation.

[0017] According to a second aspect of the invention, there is provided a method for dialogue enhancing audio content having one or more audio components, each component associated with a spatial location, the method comprising: receiving a first audio signal presentation of said audio components intended for playback on a first audio reproduction system, receiving a set of presentation transformation parameters configured to enable transformation of the first audio signal presentation into a second audio signal presentation intended for playback on a second audio reproduction system, receiving a set of dialogue estimation parameters configured to enable estimation of a dialogue component from the first audio signal presentation, applying the set of presentation transformation parameters to the first audio signal presentation to form a second audio signal presentation, applying the set of dialogue estimation parameters to the first audio signal presentation to form a dialogue presentation of the dialogue component, and combining the dialogue presentation with the second audio signal presentation to form a dialogue enhanced audio signal presentation for playback on the second audio reproduction system, wherein only one of the first audio signal presentation and the second audio signal presentation is a binaural audio signal presentation.

[0018] According to a third aspect of the present invention, there is provided a method for dialogue enhancing audio content having one or more audio components, each component associated with a spatial location, the method comprising: receiving a first audio signal presentation of said audio components intended for playback on a first audio reproduction system, receiving a set of presentation transformation parameters configured to enable transformation of the first audio signal presentation into a second audio signal presentation intended for playback on a second audio reproduction system, receiving a set of dialogue estimation parameters configured to enable estimation of a dialogue component from the second audio signal presentation, applying the set of presentation transformation parameters to the first audio signal presentation to form a second audio signal presentation, applying the set of dialogue estimation parameters to the second audio signal presentation to form a dialogue presentation of the dialogue component, and summing the dialogue presentation with the second audio signal presentation to form a dialogue enhanced audio signal presentation for playback on the second audio reproduction system, wherein only one of the first audio signal presentation and the second audio signal presentation is a binaural audio signal presentation.

[0019] According to a fourth aspect of the present invention, there is provided a decoder for dialogue enhancing audio content having one or more audio components, each component associated with a spatial location, the decoder comprising: a core decoder for receiving and decoding a first audio signal presentation of said audio components intended for playback on a first audio reproduction system and a set of dialogue estimation parameters configured to enable estimating a dialogue component from the first audio signal presentation, a dialogue estimator for applying the set of dialogue estimation parameters to the first audio signal presentation to form a dialogue presentation of the dialogue component, and means for combining the dialogue presentation with a second audio signal presentation to form a dialogue enhanced audio signal presentation for playback on a second audio reproduction system, only one of the first and second audio signal presentations being a binaural audio signal presentation.

[0020] According to a fifth aspect of the present invention there is provided a decoder for dialogue enhancing audio content having one or more audio components. Each component is associated with a spatial location, and the decoder comprises a core decoder receiving a first audio signal presentation of said audio component intended for reproduction on a first audio reproduction system, a set of presentation transformation parameters configured to enable transforming the first audio signal presentation into a second audio signal presentation intended for reproduction on a second audio reproduction system, and a set of dialogue estimation parameters configured to enable estimating a dialogue component from the first audio signal presentation, a transformation unit configured to apply the set of presentation transformation parameters to the first audio signal presentation to form a second audio signal presentation intended for reproduction on the second audio reproduction system, a dialogue estimator applying the set of dialogue estimation parameters to the first audio signal presentation to form a dialogue presentation of the dialogue component, and means for combining the dialogue presentation with the second audio signal presentation to form a dialogue enhanced audio signal presentation for reproduction on the second audio reproduction system, wherein only one of the first audio signal presentation and the second audio signal presentation is a binaural audio signal presentation.

[0021] According to a sixth aspect of the present invention there is provided a decoder for dialogue enhancing audio content having one or more audio components. Each component is associated with a spatial location, and the decoder comprises a core decoder receiving a first audio signal presentation of the audio component intended for playback on a first audio reproduction system, a set of presentation transformation parameters configured to enable transforming the first audio signal presentation into a second audio signal presentation intended for playback on a second audio reproduction system, and a set of dialogue estimation parameters configured to enable estimating a dialogue component from the first audio signal presentation, a transformation unit configured to apply the set of presentation transformation parameters to the first audio signal presentation to form a second audio signal presentation intended for playback on the second audio reproduction system, a dialogue estimator applying the set of dialogue estimation parameters to the second audio signal presentation to form a dialogue presentation of the dialogue component, and a summation block to add the dialogue presentation with the second audio signal presentation to form a dialogue enhanced audio signal presentation for playback on the second audio reproduction system, wherein one of the first audio signal presentation and the second audio signal presentation is a binaural audio signal presentation.

[0022] The invention is based on the insight that a dedicated set of parameters may provide an efficient way to extract a dialogue representation from one audio signal presentation. The extracted dialogue representation may then be combined with another audio signal presentation, where at least one of the presentations is a binaural presentation. According to the invention, there is no need to reconstruct the original audio objects to enhance the dialogue. Instead, the dedicated parameters are applied directly to the presentation of the audio objects, e.g. binaural presentation, stereo presentation, etc. The inventive concept allows for a variety of individual embodiments, each with their own individual advantages.

[0023] It is noted that the term "dialogue enhancement" herein is not restricted to amplifying or boosting dialogue components, but rather may also relate to the attenuation of selected dialogue components. Thus, in general, the term "dialogue enhancement" refers to a level modification of one or more dialogue-related components of the audio content. The gain factor G of the level modification may be less than 0 to attenuate dialogue, or greater than 0 to emphasize dialogue.

[0024] In some embodiments, both the first and second presentations are binaural presentations (reverberant or anechoic). If only one is binaural, the other presentation may be a stereo or surround audio signal presentation.

[0025] In case of different presentations, the dialogue estimation parameters may also be configured to perform a presentation transformation, such that the dialogue presentation corresponds to the second audio signal presentation.

[0026] The invention may advantageously be implemented in a particular type of so-called simulcast system, in which the encoded bitstream also comprises a set of transformation parameters suitable for transforming a first audio signal presentation into a second audio signal presentation. [Brief description of the drawings]

[0027] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Figure 1] Fig. 1 shows a schematic overview of the HRIR convolution process for two sound sources or objects, where each channel or object is processed by a pair of HRIR / BRIR. [Diagram 2] FIG. 13 shows a schematic diagram of dialogue enhancement in a stereo context. [Diagram 3] FIG. 1 is a schematic block diagram illustrating the principles of dialogue enhancement according to the present invention; [Figure 4]FIG. 1 is a schematic block diagram of a single presentation dialog enhancement according to an embodiment of the present invention. [Diagram 5] FIG. 4 is a schematic block diagram of a dual presentation dialog enhancement according to a further embodiment of the present invention; [Figure 6] FIG. 6 is a schematic block diagram of the binaural dialogue estimator in FIG. 5 according to a further embodiment of the present invention. [Figure 7] 1 is a schematic block diagram of a simulcast decoder implementing dialogue enhancement according to an embodiment of the present invention. [Figure 8] FIG. 11 is a schematic block diagram of a simulcast decoder implementing dialogue enhancement according to another embodiment of the present invention. [Figure 9] 13a and 13b are schematic block diagrams of a simulcast decoder implementing dialogue enhancement according to yet another embodiment of the present invention; [Figure 10] 13 is a schematic block diagram of a simulcast decoder implementing dialogue enhancement according to yet another embodiment of the present invention. [Figure 11] 13 is a schematic block diagram of a simulcast decoder implementing dialogue enhancement according to yet another embodiment of the present invention. [Figure 12] FIG. 11 is a schematic block diagram illustrating yet another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] The systems and methods disclosed below may be implemented as software, firmware, hardware, or a combination thereof. In hardware implementations, the division of tasks, referred to as "stages" in the following description, does not necessarily correspond to division into physical units. Conversely, one physical component may have multiple functions, and one task may be performed by several cooperating physical components. Some or all of the components may be implemented as software executed by a digital signal processor or microprocessor, or as hardware, or as an application specific integrated circuit. Such software may be distributed on a computer readable medium, which may include computer storage media (or non-transitory media) and communication media (or transitory media). As is well known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information, such as computer readable instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices or any other medium that can be used to store desired information and that can be accessed by a computer. Additionally, those skilled in the art will be familiar with the fact that communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal, such as a carrier wave or other transport mechanism, and includes any information delivery media.

[0029] Various ways of implementing embodiments of the present invention are discussed with reference to Figures 3 to 6. All these embodiments generally relate to systems and methods for applying dialogue enhancement to an input audio signal having one or more audio components, each component being associated with a spatial location. The blocks shown are typically implemented in a decoder.

[0030] In the presented embodiment, the input signal is preferably decomposed into time / frequency tiles, for example by a filter bank, e.g. a quadrature mirror filter (QMF), a discrete Fourier transform (DFT), a discrete cosine transform (DCT) or any other means that splits the input signal into various frequency bands. The result of such a transformation is a representation of the input signal x for an input with index i and discrete time index n. i [n] is the subband signal x for time slot (or frame) k and subband b i For example, consider the estimation of binaural dialogue presentation from stereo presentation: x j [b,k], j=1,2 represents the subband signals of the left and right stereo channels, and d i Let [b,k], i=1,2 denote the subband signals of the estimated left and right binaural dialogue signals. The dialogue estimate may be computed as follows:

[0031]

number

[0032] The dialogue parameters w may be calculated in the encoder and encoded using the techniques disclosed in U.S. Provisional Patent Application No. 62 / 209,735, filed August 25, 2015, which is incorporated herein by reference. These parameters w are then transmitted in the bitstream and decoded by the decoder, which then applies them using the above equation. Due to the linearity of the estimation, the encoder calculations can be implemented using a Minimum Mean Square Error (MMSE) method if a target signal (clean dialogue or an estimate of clean dialogue) is available.

[0033] The choice of P and the number of time slots in K is a trade-off between quality and bitrate. Furthermore, the parameter w can be adjusted to reduce the bitrate (at the expense of lower quality), e.g., w when i ≠ j. ijm Bp,K= 0 and these parameters can be constrained by simply not transmitting them. The choice of M is also a quality / bitrate tradeoff. See U.S. Patent Application No. 62 / 209,742, filed August 25, 2015, which is incorporated herein by reference. The parameter w is generally complex-valued since binauralization of the signal introduces ITD (phase difference). However, the parameter can be constrained to be real-valued in order to reduce the bitrate. Furthermore, it is well known that humans are not sensitive to phase and time differences between left and right signals above a certain frequency, the phase / magnitude cutoff frequency around 1.5-2 kHz. Thus, above that frequency, binaural processing is typically done such that no phase difference is introduced between the left and right binaural signals, and thus the parameters can be real-valued without loss of quality (see Non-Patent Document 2). The above quality / bitrate tradeoff can be made independently in each time / frequency tile. [Non-Patent Document 2] Breebaart, J., Nater, F., Kohlrausch, A. (2010). Spectral and spatial parameter resolution requirements for parametric, filter-bank-based HRTF processing. J. Audio Eng. Soc., 58 No 3, p.126-140 In general, it is suggested to use an estimator of the following form:

[0034]

number

[0035] The above estimator can be conveniently expressed in matrix notation as follows (time / frequency tile indices omitted for simplicity of notation):

[0036]

number

[0037]

number

[0038] Referring to Fig. 3, a first audio signal representation 31 is rendered from an immersive audio signal comprising a plurality of spatialized audio components. This first audio signal representation is provided to a dialogue estimator 32 to provide a representation 33 of one or more extracted dialogue components. The dialogue estimator 32 is provided with a dedicated set of dialogue estimation parameters 34. The dialogue representation is level modified (e.g. boosted) by a gain block 35 and then combined with a second representation 36 of the audio signal to form a dialogue enhanced output 37. As will be discussed later, the combination may be a simple addition, but may also include adding the dialogue representation and the first representation followed by applying a transform to the sum to form a dialogue enhanced second presentation.

[0039] According to the invention, at least one of the presentations is a binaural presentation (reverberant or anechoic). As will be further discussed below, the first and second presentations may be different, and the dialogue presentation may or may not correspond to the second presentation. For example, the first audio signal presentation may be intended for playback on a first audio reproduction system, e.g., a set of loudspeakers, while the second audio signal presentation may be intended for playback on a second audio reproduction system, e.g., headphones.

[0040] Single Presentation In the decoder embodiment in Fig. 4, the first and second presentations 41, 46 as well as the dialogue presentation 43 are all binaural presentations (reverberant or anechoic). Thus, the (binaural) dialogue estimator 42 - and dedicated parameters 44 - estimates the binaural dialogue component, which is level-corrected in block 45 and added to the second audio presentation 46 to form the output 47.

[0041] In the embodiment of FIG. 4, the parameters 44 are not configured to perform any presentation transformation. Nevertheless, for best quality, the binaural dialogue estimator 42 should be complex-valued in the frequency band up to the phase / magnitude cutoff frequency. To illustrate why a complex-valued estimator may be needed even when no presentation transformation is performed, consider estimating binaural dialogue from a binaural signal that is a mixture of binaural dialogue and other binaural background content. Optimal extraction of dialogue often involves subtracting parts of, for example, the right binaural signal from the left binaural signal to cancel out the background content. Since binaural processing, by its very nature, introduces time (phase) differences between the left and right signals, those phase differences need to be compensated for before any subtraction can be performed, and such compensation requires complex-valued parameters. Indeed, when examining the results of MMSE calculations of parameters, the parameters generally appear as complex values ​​unless they are constrained to be real-valued. In practice, the choice between complex-valued and real-valued parameters is a trade-off between quality and bit rate. As mentioned above, the parameters can be real-valued above the frequency phase / magnitude cutoff frequency without any quality loss, taking advantage of the insensitivity to fine structure waveform phase differences at high frequencies.

[0042] Two Presentations In the decoder embodiment of Fig. 5, the first and second presentations are different. In the illustrated example, the first presentation 51 is a non-binaural presentation (e.g. stereo 2.0 or surround 5.1), while the second presentation 56 is a binaural presentation. In this case, the set of dialogue estimation parameters 54 is configured to allow the binaural dialogue estimator 52 to estimate the binaural dialogue presentation 53 from the non-binaural presentation 51. Note that the presentation may be reversed. In that case, the binaural dialogue estimator would for example estimate a stereo dialogue presentation from a binaural audio presentation. In either case, the dialogue estimator needs to extract the dialogue components and perform a presentation transformation. The binaural dialogue presentation 53 is level corrected by block 55 and added to the second presentation 56.

[0043] As shown in Fig. 5, the binaural dialogue estimator 52 receives a single set of parameters 54 configured to perform two operations: dialogue extraction and presentation transformation. However, as shown in Fig. 6, it is also possible that the (reverberant or anechoic) binaural dialogue estimator 62 receives two sets of parameters D1, D2, one set (D1) configured to extract dialogue (dialogue extraction parameters) and one set (D2) configured to perform dialogue presentation transformation (dialogue transformation parameters). This may be advantageous in implementations where one or both of these subsets D1, D2 are already available at the decoder. For example, the dialogue extraction parameters D1 may be available for normal dialogue extraction as shown in Fig. 2. Furthermore, the parameter transformation parameters D2 may be available in a simulcast implementation, as discussed later.

[0044] 6, the dialogue extraction (block 62a) is shown to occur before the presentation transformation (block 62b), although this order may of course be reversed. For reasons of computational efficiency, even if the parameters are provided as two separate sets D1, D2, it may be advantageous to first combine the two sets of parameters into a combined matrix transform and then apply this combined transform to the input signal 61.

[0045] Further note that the dialogue extraction is one-dimensional and the extracted dialogue can be a mono representation. The transformation parameter D2 is then positional metadata and the presentation transformation involves rendering the mono dialogue using the HRTF, HRIR or BRIR corresponding to that position. Alternatively, if the desired rendered dialogue presentation is intended for loudspeaker playback, the mono dialogue can be rendered using loudspeaker rendering techniques such as amplitude panning or vector-based amplitude panning (VBAP).

[0046] Simulcast Implementation 7-11 illustrate embodiments of the present invention in the context of a simulcast system, i.e., a system in which an audio presentation is encoded and transmitted to a decoder along with a set of transformation parameters that allow the decoder to transform the audio presentation into a different presentation (e.g., shown as a binaural presentation for headphones) adapted to the intended playback system. Various aspects of such a system are described in detail in co-pending, unpublished U.S. Provisional Patent Application No. 62 / 209,735, filed Aug. 25, 2015, which is incorporated herein by reference. For simplicity, FIGS. 7-11 show only the decoder side.

[0047] As shown in FIG. 7, the core decoder 71 receives an encoded bitstream 72 containing an initial audio signal representation of the audio component. In the illustrated case, this initial representation is a stereo representation z, but it could be any other representation. The bitstream 72 also contains a set of presentation transformation parameters w(y). These parameters are used as matrix coefficients to perform a matrix transformation 73 of the stereo signal z to generate a reconstructed anechoic binaural signal ^y. The transformation parameters w(y) were determined in the encoder as discussed in U.S. Provisional Patent Application No. 62 / 209,735. In the illustrated case, the bitstream 72 also contains a set of parameters w(f) that are used as matrix coefficients to perform a matrix transformation 74 of the stereo signal z to generate a reconstructed input signal ^f for the anechoic environment simulation, here a feedback delay network (FDN) 75. These parameters w(f) were determined in a similar manner to the presentation transformation parameters w(y). The FDN 75 receives the input signal ^f and outputs the acoustic environment simulation FDN out , the output of which may be combined with the anechoic binaural signal ^y to provide a reverberant binaural signal.

[0048] In the embodiment of Figure 7, the bitstream further includes a set of dialogue estimation parameters w(D) that are used as matrix coefficients in a dialogue estimator 76 to perform a matrix transformation of the stereo signal z to generate an anechoic binaural dialogue representation D. The dialogue representation D is level modified (e.g. boosted) in block 77 to generate the reconstructed anechoic signal ^y and the anechoic environment simulation output FDN out and are combined in summing block 78.

[0049] FIG. 7 is essentially an implementation of the embodiment of FIG. 5 in a simulcast context.

[0050] In the embodiment of Figure 8, a stereo signal z, a set of transformation parameters w(y) and a further set of parameters w(f) are received and decoded in the same manner as in Figure 7, with elements 71, 73, 74, 75, 78 being equivalent to those discussed with respect to Figure 7. In addition, the bitstream 82 now also includes a set of dialogue estimation parameters w(D1) that are applied by a dialogue estimator 86 to the signal z. However, in this embodiment, the dialogue estimation parameters w(D1) are not configured to provide any presentation transformation. Thus, the dialogue presentation output D from the dialogue estimator 86 is stereo corresponds to the initial audio signal presentation, here a stereo presentation. Dialogue presentation D stereo is level corrected in block 87 and then added to signal z in summation 88. The dialogue enhanced signal (z+D stereo ) is then transformed by a set of transformation parameters w(y).

[0051] Figure 8 can be seen as an implementation of the embodiment of Figure 6 in a simulcast context, where w(D1) is used as D1 and w(y) is used as D2. However, whereas in Figure 6 both sets of parameters are applied in the dialogue estimator 62, in Figure 8 only the extracted dialogue D stereo is added to the signal z and the transformation w(y) is applied to the combined signal (z+D).

[0052] Note that the set of parameters w(D1) may be the same as the dialogue enhancement parameters used to provide dialogue enhancement of stereo signals in a simulcast implementation. This alternative is shown in FIG. 9a, where a dialogue extraction 96a is shown as being part of the core decoder 91. Furthermore, in FIG. 9a, a presentation transform 96b using the parameter set w(y) is performed before the gain and separately from the transformation of the signal z. Thus, this embodiment is more similar to the case shown in FIG. 6, where the dialogue estimator 62 includes both transforms 96a, 96b.

[0053] Figure 9b shows a modified version of the embodiment of figure 9a, where the presentation transformation is not performed using the parameter set w(y) but using an additional set of parameters w(D2) that are provided in the bitstream section dedicated to binaural dialogue estimation.

[0054] In one embodiment, the dedicated presentation transform w (D2) mentioned above in FIG. 9b is a real-valued, single-tap (M=1), full-band (P=1) matrix.

[0055] FIG. 10 shows a modified version of the embodiment of FIGS. 9a-b. In this case, the dialogue extractor 96a still produces a stereo dialogue presentation D stereo , also shown as being part of the core decoder 91. However, here the stereo dialogue presentation D stereo is added directly to the anechoic binaural signal ^y (with the anechoic environment simulation from the FDN) after level modification in block 97.

[0056] Please note that combining signals with different presentations, e.g. adding a stereo dialogue signal to a binaural signal (containing unenhanced binaural dialogue components), will of course lead to spatial localization artifacts, since the unenhanced binaural dialogue components will be perceived as spatially different compared to a stereo presentation of the same components.

[0057] Furthermore, it is noted that combining signals with different presentations can lead to constructive addition of dialogue components in some frequency bands and destructive addition in others. The reason is that binaural processing introduces ITDs (phase differences), adding signals that are in phase in some frequency bands and out of phase in others, which leads to coloring artifacts in the dialogue components (and the coloring can be different for the left and right ears). In one embodiment, phase differences above the phase / magnitude cutoff frequencies are avoided in binaural processing to reduce this type of artifacts.

[0058] As a final remark on combining signals with different presentations, it is generally acknowledged that binaural processing can reduce dialogue intelligibility. If the goal of dialogue enhancement is to maximize intelligibility, it may be advantageous to extract and level correct (e.g. boost) a non-binaural dialogue signal. More specifically, even if the final presentation intended for playback is binaural, it may be advantageous in such cases to extract and level correct (e.g. boost) a stereo dialogue signal and combine it with the binaural presentation (trading off timbre coloration and spatial localization artifacts, as described above, for improved intelligibility).

[0059] In the embodiment of Figure 11, a stereo signal z, a set of transformation parameters w(y) and a further set of parameters w(f) are received and decoded in the same manner as in Figure 7. Additionally, as in Figure 8, the bitstream also includes a set of dialogue estimation parameters w(D1) that are not configured to provide any presentation transformation. However, in this embodiment, the dialogue estimation parameters w(D1) are applied by the dialogue estimator 16 to the reconstructed anechoic binaural signal ^y to provide an anechoic binaural dialogue presentation D. This dialogue presentation D is level corrected by block 117 and converted to an FDN representation in summation 118. outand added to the signal ^y as well.

[0060] Figure 11 is essentially an implementation in a simulcast context of the single presentation embodiment of Figure 5. However, it can also be seen as reversing the order of D1 and D2 of the implementation of Figure 6. Here, w(D1) is still used as D1, and w(y) is used as D2. However, in Figure 6, both sets of parameters were applied in the dialog estimator, while in Figure 9, the conversion parameter D2 has already been applied to obtain ^y, and the dialog estimator 16 only needs to apply the parameter w(D1) to the signal ^y to obtain the reverberant binaural dialog presentation D.

[0061] In some applications, it may be desirable to apply different processing depending on the desired value of the dialog-level correction factor G. In one embodiment, an exemplary appropriate processing is selected based on a determination of whether the factor G is greater than or less than a given threshold. Of course, there may be two or more thresholds and two or more alternative processes. For example, if th1 and th2 are two given thresholds, a first process when G < th1, a second process when th1 ≤ G < th2, and a third process when G ≥ th2.

[0062] In the individual example shown in Figure 12, the threshold is 0, and the first process is applied when G < 0 (dialog attenuation), and the second process is applied when G > 0 (dialog enhancement). For this purpose, the circuit of Figure 12 includes selection logic in the form of a switch 121 having two positions A and B. The switch is configured to receive the value of the gain factor G from block 122 and take position A when G < 0 and position B when G > 0.

[0063] When the switch is in position A, the circuitry is now configured to combine the estimated stereo dialogue from matrix transform 86 with the stereo signal z, and then perform the matrix transform 73 on the combined signal to generate a reconstructed anechoic binaural signal. The output from feedback delay network 75 is then combined with this signal at 78. Note that this process essentially corresponds to Figure 8 discussed above.

[0064] When the switch is in position B, the circuitry is now configured to apply transformation parameters w(D2) to the stereo dialogue from matrix transform 86 to provide a binaural dialogue estimate. This estimate is then added to the anechoic binaural signal from transform 73 and the output from feedback delay network 75. Note that this process essentially corresponds to FIG. 9b discussed above.

[0065] Those skilled in the art will recognize many other alternatives for the respective processing in positions A and B. For example, the processing when the switch is in position B may instead correspond to that of FIG. 10. However, the main contribution of the embodiment of FIG. 12 is the introduction of switch 121, which allows alternative processing depending on the value of the gain factor G.

[0066] interpretation References throughout this specification to "one embodiment," "some embodiments," or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of the invention. Thus, the appearances of the phrases "in one embodiment," "some embodiments," or "in an embodiment" throughout this specification may, but do not necessarily, all refer to the same embodiment. Furthermore, particular features, structures, or characteristics may be combined in any suitable manner, as will be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

[0067] As used herein, unless otherwise noted, the use of ordinal adjectives "first," "second," "third," etc. to describe a common object is intended merely to indicate that different instances of a similar object are being referred to and is not intended to imply that the objects so described must be in a given order in time, space, ranking, or in any other way.

[0068] In the appended claims and in the description of this document, any of the terms having, consisting of or including are open terms meaning to include at least the element / feature that follows it but not to exclude others. Thus, the term having when used in the claims should not be interpreted as being limited to the means or elements or steps listed thereafter. For example, the scope of an expression of a device having A and B should not be limited to a device consisting of elements A and B only. Any of the terms including and including used in this document are also open terms meaning to include at least the element / feature that follows it but not to exclude others. Thus, including is synonymous with having and means having.

[0069] As used herein, the term "exemplary" is used in the sense of giving an example rather than a denoting a quality, i.e., an "exemplary embodiment" is an embodiment that is provided as an example, rather than necessarily an embodiment that is exemplary in nature.

[0070] In the above description of exemplary embodiments of the invention, it should be understood that various features of the invention are sometimes grouped together in a single embodiment, drawing or description in order to facilitate flow of the disclosure and understanding of one or more of the various inventive aspects. However, this method of disclosure is not to be interpreted as reflecting an intention that the claimed invention requires more than is expressly recited in each claim. Rather, as the appended claims reflect, aspects of the invention lie in less than all features of a single above-disclosed embodiment. Thus, the appended claims are hereby expressly incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment of the invention.

[0071] Furthermore, even if some embodiments described herein include some features but not others included in other embodiments, combinations of features of different embodiments are intended to be within the scope of the present invention and form different embodiments, as will be understood by those skilled in the art. For example, in the appended claims, any of the claimed embodiments can be used in any combination.

[0072] Additionally, some of the embodiments are described herein as a method or combination of method elements that can be implemented by a processor of a computer system or other means for performing the functions. Thus, a processor with the necessary instructions for performing such a method or method element constitutes a means for performing the method or method element. Additionally, the described elements of the apparatus embodiments are examples of means for performing the functions performed by the elements to implement the invention.

[0073] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the present invention can be practiced without such specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order to avoid obscuring an understanding of this description.

[0074] Similarly, the term coupled, when used in the claims, should not be interpreted as being limited to only direct connections. The terms "coupled" and "connected" and their derivatives may be used. It should be understood that these terms are not intended as synonyms for each other. Thus, the scope of the expression device A coupled to device B should not be limited to devices or systems in which the output of device A is directly connected to the input of device B. It means that there is a path between the output of A and the input of B, which may be a path that includes other devices or means. "Coupled" may mean that two or more elements are in direct physical or electrical contact, or that two or more elements are not in direct contact with each other, but still cooperate or interact with each other.

[0075] Thus, while specific embodiments of the present invention have been described, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the present invention. It is intended that all such changes and modifications be claimed as falling within the scope of the present invention. For example, any formulas given above are merely representative of procedures that may be used. Functions may be added or deleted from the block diagrams, and operations may be interchanged between functional blocks. Steps may be added or deleted to the methods described within the scope of the present invention.

[0076] Several aspects will be described. [Aspect 1] 1. A method for dialogue enhancing audio content having one or more audio components, each component associated with a spatial location, the method comprising: providing a first audio signal presentation of said audio component intended for playback on a first audio playback system; providing a second audio signal presentation of said audio component intended for playback on a second audio playback system; receiving a set of dialogue estimation parameters configured to enable estimation of dialogue components from the first audio signal presentation; applying the set of dialogue estimation parameters to the first audio signal representation to form a dialogue representation of the dialogue component; combining the dialogue presentation with the second audio signal presentation to form a dialogue-enhanced audio signal presentation for playback on the second audio playback system; At least one of the first and second audio signal presentations is a binaural audio signal presentation. method. [Aspect 2] 2. The method of embodiment 1, wherein the first and second audio signal presentations are binaural audio signal presentations. [Aspect 3] 2. The method of claim 1, wherein only one of the first and second audio signal presentations is a binaural audio signal presentation. Aspect 4 4. The method of embodiment 3, wherein the other of the first and second audio signal presentations is a stereo or surround audio signal presentation. Aspect 5 5. The method of claim 3 or 4, further comprising receiving a set of dialogue transformation parameters and applying the set of dialogue transformation parameters before or after application of the set of dialogue estimation parameters to form a transformed dialogue presentation corresponding to the second audio signal presentation. Aspect 6 5. The method of claim 3 or 4, wherein the dialogue estimation parameters are also configured to perform a presentation transformation such that the dialogue presentation corresponds to the second audio signal presentation. Aspect 7 3. The method of claim 2, wherein providing the first audio signal presentation comprises receiving an initial audio signal presentation and a set of presentation transformation parameters, and applying the set of presentation transformation parameters to the initial audio signal presentation. Aspect 8 A method described in any one of aspects 1 to 7, further comprising receiving a set of presentation transformation parameters configured to enable conversion of the first audio signal presentation to the second audio signal presentation, and applying the set of presentation transformation parameters to the first audio signal presentation to form the second audio signal presentation. Aspect 9 9. The method of embodiment 8, further comprising applying the set of presentation transformation parameters before or after application of the set of dialogue estimation parameters to form a transformed dialogue presentation corresponding to the second audio signal presentation. Aspect 10 9. The method of claim 8, wherein combining the dialogue presentation with the second audio signal presentation includes forming a sum of the dialogue presentation and the first audio signal presentation and applying the set of presentation transformation parameters to the sum. Aspect 11 11. The method of any one of aspects 1-10, wherein the first audio signal representation is received from an encoder. Aspect 12 12. The method of any one of aspects 1-11, further comprising applying a level modification by a factor G to the dialogue presentation. Aspect 13 13. The method of embodiment 12, wherein a first action is applied when G is less than a given threshold, and a second action is applied when G is greater than said threshold. Aspect 14 14. The method of embodiment 13, wherein the threshold is equal to 0, with G<0 representing dialogue attenuation and G>0 representing dialogue emphasis. Aspect 15 15. The method of claim 13 or 14, wherein the first process comprises forming a sum of the dialogue representation and the first audio signal representation and applying a set of presentation transformation parameters to the sum. Aspect 16 16. The method of any one of aspects 13 to 15, wherein the second processing includes applying a set of presentation transformation parameters before or after application of the set of dialogue estimation parameters to form a transformed dialogue presentation corresponding to the second audio signal presentation. Aspect 17 1. A method for dialogue enhancing audio content having one or more audio components, each component associated with a spatial location, the method comprising: receiving a first audio signal presentation of the audio component intended for playback on a first audio playback system; receiving a set of presentation transformation parameters configured to enable transformation of the first audio signal presentation into a second audio signal presentation intended for playback on a second audio playback system; receiving a set of dialogue estimation parameters configured to enable estimation of dialogue components from the first audio signal representation; applying the set of presentation transformation parameters to the first audio signal presentation to form a second audio signal presentation; applying the set of dialogue estimation parameters to the first audio signal representation to form a dialogue representation of the dialogue component; combining the dialogue presentation with the second audio signal presentation to form a dialogue-enhanced audio signal presentation for playback on the second audio playback system; only one of the first audio signal presentation and the second audio signal presentation is a binaural audio signal presentation; method. Aspect 18 18. The method of claim 17, wherein combining the dialogue presentation with the second audio signal presentation includes forming a sum of the dialogue presentation and the first audio signal presentation and applying the set of presentation transformation parameters to the sum. Aspect 19 20. The method of claim 17, wherein the dialogue estimation parameters are also configured to perform a presentation transformation such that the dialogue presentation corresponds to the second audio signal presentation. Aspect 20 20. The method of claim 17, further comprising applying the set of presentation transformation parameters before or after application of the set of dialogue estimation parameters to form a transformed dialogue presentation corresponding to the second audio signal presentation. Aspect 21 the dialog presentation is a mono presentation, the method further comprising: receive location data relating to said dialog component; and rendering the mono dialogue presentation using the position data prior to combining with the second audio signal presentation. The method of embodiment 17. Aspect 22 The rendering is: selecting a head-related transfer function (HRTF) from a library based on said position data; applying the selected HRTFs to the mono dialogue presentation. The method of embodiment 21. Aspect 23 22. The method of embodiment 21, wherein the rendering comprises amplitude panning. Aspect 24 1. A method for dialogue enhancing audio content having one or more audio components, each component associated with a spatial location, the method comprising: receiving a first audio signal presentation of the audio component intended for playback on a first audio playback system; receiving a set of presentation transformation parameters configured to enable transformation of the first audio signal presentation into the second audio signal presentation intended for playback on a second audio playback system; receiving a set of dialogue estimation parameters configured to enable estimation of dialogue components from the second audio signal representation; applying the set of presentation transformation parameters to the first audio signal presentation to form a second audio signal presentation; applying the set of dialogue estimation parameters to the second audio signal representation to form a dialogue representation of the dialogue component; adding said dialogue presentation with said second audio signal presentation to form a dialogue-enhanced audio signal presentation for playback on said second audio playback system; only one of the first audio signal presentation and the second audio signal presentation is a binaural audio signal presentation; method. Aspect 25 1. A decoder for dialogue enhancement of audio content having one or more audio components, each component associated with a spatial location, the decoder comprising: a core decoder for receiving and decoding a first audio signal representation of the audio component intended for playback on a first audio playback system and a set of dialogue estimation parameters configured to enable estimating a dialogue component from the first audio signal representation; a dialogue estimator that applies the set of dialogue estimation parameters to the first audio signal presentation to form a dialogue presentation of the dialogue component; means for combining the dialogue presentation with a second audio signal presentation to form a dialogue-enhanced audio signal presentation for playback on a second audio playback system; only one of the first and second audio signal presentations is a binaural audio signal presentation; decoder. Aspect 26 26. A decoder as described in embodiment 25, wherein one of the first and second audio signal presentations is a stereo or surround audio signal presentation. Aspect 27 27. The decoder of claim 25 or 26, wherein the core decoder is further configured to receive a set of dialogue transformation parameters, and the dialogue estimator is further configured to apply the set of dialogue transformation parameters before or after application of the set of dialogue estimation parameters to form a transformed dialogue presentation corresponding to the second audio signal presentation. Aspect 28 27. The decoder of claim 25 or 26, wherein the dialogue estimator is also configured to perform a presentation transformation using the set of dialogue estimation parameters, such that the dialogue presentation corresponds to the second audio signal presentation. Aspect 29 The core decoder is further configured to receive a set of presentation transformation parameters, the decoder further comprising: a transformation unit configured to apply said set of presentation transformation parameters to said first audio signal presentation to form said second audio signal presentation. 29. A decoder according to any one of aspects 25 to 28. Aspect 30 30. The decoder of embodiment 29, wherein the dialogue estimator is further configured to apply the set of presentation transformation parameters before or after application of the set of dialogue estimation parameters to form a transformed dialogue presentation corresponding to the second audio signal presentation. Aspect 31 30. The decoder of claim 29, wherein the means for combining the dialogue presentation with the second audio signal presentation includes an addition block for forming a sum of the dialogue presentation and the first audio signal presentation, and the transformation unit is configured to apply the set of presentation transformation parameters to the sum. Aspect 32 32. The decoder of any one of aspects 25 to 31, further comprising a level correction block configured to apply a level correction by a factor G to the dialogue presentation. Aspect 33 33. The decoder of embodiment 32, further comprising selection logic configured to select a first application of the dialogue estimation parameters when G is less than a given threshold, and a second process is applied when G is greater than the threshold. Aspect 34 34. The decoder of embodiment 33, wherein the threshold is equal to 0, with G<0 representing dialogue attenuation and G>0 representing dialogue emphasis. Aspect 35 35. The decoder of claim 33 or 34, wherein the first applying comprises forming a sum of the dialogue representation and the first audio signal representation and applying a set of presentation transformation parameters to the sum. Aspect 36 A decoder as described in any one of aspects 33 to 35, wherein the second applying includes applying a set of presentation transformation parameters before or after application of the set of dialogue estimation parameters to form a transformed dialogue presentation corresponding to the second audio signal presentation. Aspect 37 1. A decoder for dialogue enhancement of audio content having one or more audio components, each component associated with a spatial location, the decoder comprising: a core decoder receiving a first audio signal representation of the audio component intended for playback on a first audio reproduction system, a set of presentation transformation parameters configured to enable transforming the first audio signal representation into a second audio signal presentation intended for playback on a second audio reproduction system, and a set of dialogue estimation parameters configured to enable estimating a dialogue component from the first audio signal representation; a transformation unit configured to apply said set of presentation transformation parameters to said first audio signal presentation to form a second audio signal presentation intended for playback on a second audio reproduction system; a dialogue estimator that applies the set of dialogue estimation parameters to the first audio signal presentation to form a dialogue presentation of the dialogue component; means for combining the dialogue presentation with the second audio signal presentation to form a dialogue-enhanced audio signal presentation for playback on the second audio playback system; only one of the first audio signal presentation and the second audio signal presentation is a binaural audio signal presentation; decoder. Aspect 38 38. The decoder of claim 37, wherein the means for combining the dialogue presentation with the second audio signal presentation includes an addition block for forming a sum of the dialogue presentation and the first audio signal presentation, and the transformation unit is configured to apply the set of presentation transformation parameters to the sum. Aspect 39 38. The decoder of embodiment 37, wherein the dialogue estimator is also configured to perform a presentation transformation using the set of dialogue estimation parameters, such that the dialogue presentation corresponds to the second audio signal presentation. Aspect 40 38. The decoder of claim 37, wherein the dialogue estimator is configured to apply the set of presentation transformation parameters before or after application of the set of dialogue estimation parameters to form a transformed dialogue presentation corresponding to the second audio signal presentation. Aspect 41 The dialogue presentation is a mono presentation, and the core decoder is further configured to receive position data relating to the dialogue components, the decoder further comprising: a renderer configured to render the mono dialogue presentation using the position data prior to combining with the second audio signal presentation. 38. A decoder according to embodiment 37. Aspect 42 The renderer: selecting a head-related transfer function (HRTF) from a library based on said position data; and configured to apply the selected HRTFs to the mono dialogue presentation. A decoder according to embodiment 41. Aspect 43 42. The decoder of embodiment 41, wherein the renderer is configured to apply amplitude panning. Aspect 44 1. A decoder for dialogue enhancement of audio content having one or more audio components, each component associated with a spatial location, the decoder comprising: a core decoder receiving a first audio signal representation of the audio component intended for playback on a first audio reproduction system, a set of presentation transformation parameters configured to enable the first audio signal representation to be transformed into a second audio signal representation intended for playback on a second audio reproduction system, and a set of dialogue estimation parameters configured to enable the estimation of a dialogue component from the first audio signal representation; a transformation unit configured to apply said set of presentation transformation parameters to said first audio signal presentation to form a second audio signal presentation intended for playback on a second audio reproduction system; a dialogue estimator that applies the set of dialogue estimation parameters to the second audio signal presentation to form a dialogue presentation of the dialogue component; a summing block for summing the dialogue representation with the second audio signal presentation to form a dialogue-enhanced audio signal presentation for playback on the second audio playback system; only one of the first audio signal presentation and the second audio signal presentation is a binaural audio signal presentation; decoder.

Claims

1. 1. A method for dialogue enhancement of audio content having one or more audio components, each component associated with a spatial location, the method comprising: providing a first audio signal presentation of the audio component intended for playback on a first audio playback system; providing a second audio signal presentation of said audio component intended for playback on a second audio playback system; receiving a set of dialogue estimation parameters configured to enable estimation of dialogue components from the first audio signal presentation; applying the set of dialogue estimation parameters to the first audio signal presentation to form a dialogue presentation of the dialogue component; combining the dialogue presentation with the second audio signal presentation to form a dialogue-enhanced audio signal presentation for playback on the second audio playback system; at least one of the first and second audio signal presentations is a binaural audio signal presentation; The method further comprises applying a level modification by a factor G to the dialogue presentation, a first operation being applied when G is less than a given threshold, and a second operation being applied when G is greater than the threshold, the second operation comprising applying a set of presentation transformation parameters before or after application of the set of dialogue estimation parameters to form a transformed dialogue presentation corresponding to the second audio signal presentation. method.

2. The method of claim 1 , wherein the first and second audio signal presentations are binaural audio signal presentations.

3. The method of claim 1 , wherein only one of the first and second audio signal presentations is a binaural audio signal presentation.

4. 4. The method of claim 3, wherein the other of the first and second audio signal presentations is a stereo or surround audio signal presentation.

5. 5. The method of claim 3 or 4, further comprising receiving a set of dialogue transformation parameters and applying the set of dialogue transformation parameters before or after application of the set of dialogue estimation parameters to form a transformed dialogue presentation corresponding to the second audio signal presentation.

6. The method of claim 2 , wherein providing the first audio signal presentation comprises receiving an initial audio signal presentation and a set of presentation transformation parameters, and applying the set of presentation transformation parameters to the initial audio signal presentation.

7. 7. The method of claim 1, further comprising receiving a set of presentation transformation parameters configured to enable conversion of the first audio signal presentation into the second audio signal presentation, and applying the set of presentation transformation parameters to the first audio signal presentation to form the second audio signal presentation.

8. 8. The method of claim 7, further comprising applying the set of presentation transformation parameters before or after application of the set of dialogue estimation parameters to form a transformed dialogue presentation corresponding to the second audio signal presentation.

9. 8. The method of claim 7, wherein combining the dialogue presentation with the second audio signal presentation comprises forming a sum of the dialogue presentation and the first audio signal presentation and applying the set of presentation transformation parameters to the sum.

10. 2. The method of claim 1, wherein the threshold is equal to 0, with G<0 representing dialogue attenuation and G>0 representing dialogue emphasis.

11. The dialog presentation is a mono presentation, the method further comprising: receiving location data relating to the dialog component; and rendering the mono dialogue presentation using the position data prior to combining with the second audio signal presentation. The method of claim 1.

12. The rendering may include: selecting a head-related transfer function (HRTF) from a library based on the position data; applying the selected HRTFs to the mono dialogue presentation; or Amplitude panning, including either The method of claim 11.

13. 13. A decoder for dialogue enhancement of audio content having one or more audio components, each component associated with a spatial location, the decoder configured to perform a method according to any one of claims 1 to 12.

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