Claims:1. A system for providing redundancy to multi-channel audio to a speaker, said system comprising:
an audio unit configured to receive a plurality of audio signals from a corresponding plurality of input channels, based on a predetermined association of each of the plurality of the audio signals with a corresponding input channel; and
a control unit operatively coupled with the audio unit and operable on receipt of an activation signal, said control unit comprising one or more processors operatively coupled with a memory, said memory storing instructions executable by the one or more processors to:
downmix the plurality of received audio signals based on any one or more primary audio signals out of the plurality of received audio signals, wherein a plurality of downmixed audio signals each comprise at least the any one or more primary audio signals,
a plurality of output channels corresponding to the plurality of input channels, the plurality of output channels operatively coupled with the control unit, and each output channel configured to transmit, from the control unit, at least one downmixed audio signal,
wherein the plurality of output channels are operatively coupled to a plurality of speakers and are configured to transmit the plurality of downmixed audio signals to the plurality of speakers.
2. The system as claimed in claim 1, wherein the system comprises a switching unit operatively coupled to the control unit, and wherein the control unit is configured to, upon activation by the switching unit, receive the activation signal.
3. The system as claimed in claim 1, wherein the plurality of input channels comprisesone or more audio channels,and wherein the one or more audio channels are at least one of a centre channel, right channel and left channel.
4. The system as claimed in claim 1, wherein the plurality of speakers are at least one of a main speaker, subwoofer and surround speaker.
5. The system as claimed in claim 1, wherein the one or more primary audio signals are associated with dialogue information.
6. The system as claimed in claim 1, wherein the control unit is configured to:
filter, by using a filtering unit, the plurality of downmixed audiosignals to form a soundtrack data stream; and
route, by using a routing unit, the soundtrack data stream, via the plurality of output channels, to the plurality of speakers, respectively, placed at predetermined positions relative to a position of a listener, wherein if any of the plurality of speakers gets damaged, remaining of the plurality of speakers configured to provide seamless audio information to the listener.
7. The system as claimed in claim 6, wherein the filtering of the plurality of downmixed audio signals includes a band pass filtering of the plurality of downmixed audio signals.
8. The system as claimed in claim 1, whereinthe plurality of output channels comprises at least one of a low frequency channel, medium frequency channel and high frequency channel corresponding to the plurality of input channels.
9. A device for providing redundancy tomulti-channel audio to a speaker, said device comprising:
one or more processors operatively coupled with a memory, said memory storing instructions executable by the one or more processors, on receipt of an activation signal, to:
receive, from an audio unit operatively coupled with the device, a plurality of audio signals from a corresponding plurality of input channels, based on a predetermined association of each of the plurality of the audio signals with a corresponding input channel; and
downmix the plurality of received audio signals based on any one or more primary audio signals out of the plurality of received audio signals, wherein the plurality of downmixed audio signals each comprise at least the any one or more primary audio signals,
a plurality of output channels corresponding to the plurality of input channels, the plurality of output channels operatively coupled with the one or more processors, and each output channel configured to transmit, from the one or more processors, at least one down-mixed audio signal,
wherein the plurality of output channels are operatively coupled to a plurality of speakers and are configured to transmit the plurality of downmixed audio signals to the plurality of speakers.
10. The device as claimed in claim 9, wherein the device comprises a switching unit, and wherein the one or more processors are configured to, upon activation by the switching unit, receive the activation signal.
11. The device as claimed in claim 9, wherein the plurality of input channels comprises one or more audio channels, and wherein the one or more audio channels are at least one of a centre channel, right channel and left channel.
12. The device as claimed in claim 9, wherein the one or more primary audio signals are associated with dialogue information.
13. The device as claimed in claim 9, wherein the one or more processors are configured to:
filter, by using a filtering unit, the plurality of downmixed audio signals to form a soundtrack data stream; and
route, by using a routing unit, the soundtrack data stream, via the plurality of output channels, to the plurality of speakers, respectively, placed at predetermined positions relative to a position of the listener, wherein if any of the plurality of speakers gets damaged, remaining of the plurality of speakers configured to provide seamless audio information to the listener.
, Description:TECHNICAL FIELD
[1] The present disclosure relates to the field of cinema (or playback) audio signals from speakers (or electroacoustic transducer). More particularly, the present disclosure relates to a means for providing redundancy to audio play back to electroacoustic transducers.

BACKGROUND
[2] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[3] Sound technology has evolved from mono sound to stereo sound and to digital surround sound technology. In mono mode, audio information is present in one channel, while, in stereo mode, audio information is present in two or more channels such as 2.1 channel, 5.1 channel, 7.1 channel and 9.1 channel surround sound (the “1” indicates a sub-woofer or low frequency effects channel). A term “stereophonic” commonly called as stereo sound refers to a method of sound reproduction in which an illusion of directionality and audible perspective is created. The creation of illusion is usually achieved by using the two or more independent audio channels through configuration of two or more loudspeaker systems. Thus, the term 'stereophonic' applies to so called 'quadraphonic' systems, 'surround sound' systems and 2-channel, 2-speaker systems.
[4] Surround sound and immersive audio systems have become standard in cinemas worldwide. "Surround sound" is a term used in audio engineering to refer to sound reproduction systems that use multiple channels and speakers to provide a listener with simulated placement of sound sources. Typically, the listener is positioned between multiple speakers. By playing a sound at different intensities through one or more of the speakers, the sound is positioned with respect to the listener and the listener experiences a sensation of being "surrounded" with sound sources to create a more interesting or realistic listening experience. Companies and consumers increasingly depend on computers, however, to create, distribute, and play back high-quality multi-channel audio content.
[5] Further, the process of producing matrix decoded surround sound involves encoding two stereophonic channels with multiple channels of audio information by manipulation of frequency and phase information. The two-channel encoded audio information is then decoded through a surround sound processor and directed to a plurality of loudspeakers, thereby presenting multiple channels of audio to listener. Proper speaker placement allows the listener to perceive audio signals emanating from the front, rear, or side depending on the speaker placement. The ideal speaker configuration employs left and right front speakers, left and right rear speakers, and a single centre front speaker. A spatial or ambience perception of sound is perceived by the listener from the rear speakers, wherein out of phase signals are present. The centre channel is a mono combination of the two-channel input signal and used to provide frontal localization of the sound source to remove the left-right perception of the two front channels.
[6] Conventionally, thesurround sound and immersive audio systemmay primarily have three or fivespeakers behind screen along with a set of sub woofers. Additionally, the system may offer a number of surround speakers that are placed along walls of places such as movie theatre, home, office etc. For immersive audio systems, there are surround speakers placed on ceilings as well. However, due to multi-channel format, the entire soundtrack may notbe mixed onto one channel. Different components of the soundtrack may be assigned to different channels that are selected from multiple channels. The most important component of the soundtrack is the dialogue and this component may be primarily assigned to the centre channel. Therefore, the centre channel is extremely critical and any failure in speaker or amplifier corresponding to the centre channel may immediately result in show cancellations in a cinema or movietheatre, as it may not possible to watch movie without dialogues. The speakers or amplifiers of the centre channel may present behind a screen of the cinema.
[7] Efforts have been made in therelated art to provide solutions to overcome problems caused by failure of centre channels and/or speakers and amplifiers associated with centre channels. One of the related art solutions installed multiple speaker systems (i.e. multiple speakers, amplifiers etc.),in cinema theatres,for the centre channel instead of onespeaker or amplifier.Incase of failure of at least oneof multiple speakers, the remaining of multiple speakersmay keep functioning. The drawback of this solution is it may cause severe phase cancellations amongthe multiple speakers and may degrade audio quality substantially.
[8] Even if cinema or movie theatre keeps spare components of speaker corresponding to the centre channel, providing access to the speakers that are located behind the screen may be often difficult, and modification of these components may result in downtime of movie running in the cinema hall. Further, sound engineers may not be available within a short time to carry out these replacements in order to prevent show cancellations.
[9] As mentioned above, even if parts are available at site, operators may not be trained to identify and rectify problem. Access to the speakers behind the screen can also be very challenging in many cinema halls. This may require the screen to be physically untied to gain access to the speakers located behind the screen. These are time-consuming processes and cannot be performed in the middle of a show. Sometimes, equipment failure may take place during the running of a cinema show or a movie. Sometimes, speakers may be damaged due to loud portions in soundtrack, Therefore,the related art solutionsmay find it difficult to carry out repairs during show times. Insomesituations, audiences are known to be unruly and may create great damage to the movie theatre interiors. The situation becomes even more critical in case of release of a new movie.Hence, the prior art solutions may not be able to avoid movie show cancellations in cinema halls or in movie theatres in case of any failure of cinema audio systems (especially centre channel and/or centre channel speaker failures).
[10] Therefore, there is a need in the art to provide an efficient, effectiveand simplemeans for providing redundancy to multi-channel audio information to speakers in the event of a failure of any component of audio system.
[11] All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
[12] In some embodiments, the numbers expressing quantities or dimensions of items, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term “about.” Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
[13] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[14] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.

OBJECTS OF THE INVENTION
[15] It is an object of the present inventionto provide asystem and device for providingredundancy to or seamless multi-channel audio information (such as playback information) to electroacoustic transducers such as speakers.
[16] It is another object of the present inventionto provide a simple and cost-effectivesystem and devicefor preventing movie show cancellations in a movie theatre in case of failure of centre channel or speaker associated with the centre channel.
[17] It is another object of the present inventionto provide a reliable and fastsystem and devicefor providingredundancy toaudio playbacksuch as dialogues, background music etc. information with enhanced sustainability and quality.
[18] It is another object of the present inventionto provide a precise, accurate and efficientsystem and devicefor providing localized audio playback or reproductionin a seamless manner without causing any phase cancellation.
[19] It is another object of the present inventionto provide a smart system and devicefor providing localized audio playback with minimum degradation to soundtrack during failure of centre channel, amplifier and/or speaker associated with the centre channel.
[20] It is another object of the present inventionto provide a system and device to provide sufficient time for sound engineers to solve a problem in case of failure of centre channel amplifier or speaker either completely or partially.

SUMMARY
[21] The present disclosure relates to the field of cinema (or playback) audio signals from a speaker (or electroacoustic transducer). More particularly, the present disclosure relates to a means for providingredundancy to audio playback to electroacoustic transducersby providing down-mixing, filtering and reroutingof audio signals.
[22] This summary is provided to introduce simplified concepts of a system for time bound availability check of an entity, which are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended for use in determining/limiting the scope of the claimed subject matter.
[23] An aspect of the present disclosure pertains to a system for providingredundancy tomulti-channel audio information to a set of speakers. The system includes:an audio unit that can be configured to receive a plurality of audio signals from a corresponding plurality of input channels based on a predetermined association of each of the plurality of the audio signals with a corresponding input channel; and a control unit that can be operatively coupled with the audio unit and operable on receipt of an activation signal.The control unit includes one or more processors that can be operatively coupled with a memory, the memory storing computer implemented instructions executable by the one or more processors todown-mix the plurality of received audio signals based on any one or more primary audio signals out of the plurality of received audio signals, wherein the plurality of down-mixed audio signals each comprise at least the any one or more primary audio signals of the plurality of received audio signals. A plurality of output channels can be corresponding to the plurality of input channels, and the plurality of output channels can be operatively coupled with the control unit such that each output channel can be configured to transmit, from the control unit, at least one down-mixed audio signal. Further, the plurality of output channels can be operatively coupled to a plurality of speakers and are configured to transmit the plurality of downmixed audio signals to the plurality of speakers.
[24] In an aspect, the system can include a switching unit that can be operatively coupled to the control unit.The control unit canbe configured to, upon activation by the switching unit, receive the activation signal.
[25] In an aspect, the plurality of input channels can include one or more audio channels, and wherein the one or more audio channels can be at least one of a centre channel, right channel and left channel.
[26] In an aspect, the plurality of speakers can be at least one of a main speaker, subwoofer and surround speaker.
[27] In an aspect, the one or more primary audio signals can be associated with dialogue information.
[28] In an aspect, the control unit can be configured to: filter, by using a filtering unit, the plurality of down-mixed audio signals to form a soundtrack data stream; and route, by using a routing unit, the soundtrack data stream, via the plurality of output channels, to the plurality of speakers, respectively, placed at predetermined positions relative to a position of a listener, wherein if any of the plurality of speakers gets damaged, remaining of the plurality of speakers configured to provide seamless audio information to the listener.
[29] In an aspect, the filtering of the plurality of downmixed audio signals can include a band pass filtering of the plurality of downmixed audio signals.
[30] In an aspect, the plurality of output channels can include at least one of a low frequency channel, medium frequency channel and high frequency channel that can be corresponding to the plurality of input channels.
[31] In an aspect, the system can be implemented in movie theatres, cinema halls or in any other places.
[32] Another aspect of the present disclosure pertains to a devicefor providing redundancy to multi-channel audio to a set of speakers. The device includes one or more processors that can be operatively coupled with a memory, said memory storing computer implemented instructions which when executed by the one or more processors, on receipt of an activation signal, to: receive, from an audio unit operatively coupled with the device, a plurality of audio signals from a corresponding plurality of input channels, based on a predetermined association of each of the plurality of the audio signals with a corresponding input channel; and down-mix the plurality of received audio signals based on any one or more primary audio signals out of the plurality of received audio signals, wherein the plurality of down-mixed audio signals each comprise at least the any one or more primary audio signals of the plurality of received audio signals. A plurality of output channels can be corresponding to the plurality of input channels, and the plurality of output channels can be operatively coupled with the one or more processors. Each output channel can be configured to transmit, from the one or more processors, at least one down-mixed audio signal. The plurality of output channels can be operatively coupled to a plurality of speakers and are configured to transmit the plurality of down-mixed audio signals to the plurality of speakers.
[33] In an aspect, the device can be operatively coupled to a switching unit, and the one or more processors can be configured to, upon activation by the switching unit, receive the activation signal.
[34] In an aspect, the plurality of input channels can include one or more audio channels, and wherein the one or more audio channels can be at least one of a centre channel, right channel and left channel.
[35] In an aspect, the one or more primary audio signals can be associated with dialogue information.
[36] In an aspect, the one or more processors can be configured to:filter, by using a filtering unit, the plurality of down-mixed audio signals to form a soundtrack data stream; androute, by using a routing unit, the soundtrack data stream, via the plurality of output channels, to the plurality of speakers, respectively, placed at predetermined positions relative to a position of a listener, wherein if any of the plurality of speakers gets damaged, remaining of the plurality of speakers can be configured to provide seamless audio information to the listener.
[37] In an aspect, the device can be implemented in movie theatres, cinema halls or in any other places.
[38] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF THE DRAWINGS
[39] The diagrams are for illustration only, which thus is not a limitation of the present disclosure, and wherein:
[40] FIG. 1 illustrates an exemplary block diagramrepresentation of a system for providing redundancy tomulti-channel audio information to a set of speakers,in accordance with an embodiment of the present disclosure.
[41] FIG. 2 illustrates an exemplary block diagram representation of an audio unit of FIG. 1, in accordance with an embodiment of the present disclosure.
[42] FIG. 3 illustrates an exemplary representation of a mixing unit of FIG. 1, in accordance with an embodiment of the present disclosure.
[43] FIG. 4 illustrates an exemplary representation of a filtering unit of FIG. 1, in accordance with an embodiment of the present disclosure.
[44] FIG. 5 illustrates an exemplary block diagram representation of a devicefor providing redundancy tomulti-channel audio information to a set of speakers,in accordance with an embodiment of the present disclosure.
[45] FIG. 6 illustrates an exemplary representationof typical layout of speakers and channels in a cinema, in accordance with an embodiment of the present disclosure.
[46] FIG. 7 illustrates an exemplary side view representation of speaker placement in a cinema,in accordance with an embodiment of the present disclosure.
[47] FIG. 8 illustrates an exemplary signal flow of audio in a cinema equipped with a 5.1 surround audio system, in accordance with an embodiment of the present disclosure.
[48] FIG. 9 illustrates a schematic layout of audio signal flow,in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION
[49] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[50] In the following description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present invention. It will be apparent to one skilled in the art that embodiments of the present invention may be practiced without some of these specific details.
[51] Embodiments of the present invention include various steps, which will be described below. The steps may be performed by hardware components or may be embodied in machine-executable instructions, which may be used to cause a general-purpose or special-purpose processor programmed with the instructions to perform the steps. Alternatively, steps may be performed by a combination of hardware, software, and firmware and/or by human operators.
[52] The present disclosure relates to the field of broadcasting (or playback) audio signals from a speaker (or electroacoustic transducer). More particularly, the present disclosure relates to a means for providing redundancy to audio playback to electroacoustic transducers by providing down-mixing, filtering and rerouting of audio signals.
[53] An aspect of the present disclosure pertains to a system for providing redundancy tomulti-channel audio information to a set of speakers. The system includes: an audio unit that can be configured to receive a plurality of audio signals from a corresponding plurality of input channels based on a predetermined association of each of the plurality of the audio signals with a corresponding input channel; and a control unit that can be operatively coupled with the audio unit and operable on receipt of an activation signal. The control unit includes one or more processors that can be operatively coupled with a memory, the memory storing device implemented instructions executable by the one or more processors to down-mix the plurality of received audio signals based on any one or more primary audio signals out of the plurality of received audio signals, wherein the plurality of down-mixed audio signals each comprise at least the any one or more primary audio signals of the plurality of received audio signals. A plurality of output channels can be corresponding to the plurality of input channels, and the plurality of output channels can be operatively coupled with the control unit such that each output channel can be configured to transmit, from the control unit, at least one down-mixed audio signal. Further, the plurality of output channels can be operatively coupled to a plurality of speakers and are configured to transmit the plurality of downmixed audio signals to the plurality of speakers.
[54] In an aspect, the system can include a switching unit that can be operatively coupled to the control unit. The control unit can be configured to, upon activation by the switching unit, receive the activation signal.
[55] In an aspect, the plurality of input channels can include one or more audio channels, wherein the one or more audio channels can be at least one of a centre channel, right channel and left channel.
[56] In an aspect, the plurality of speakers can be at least one of a main speaker, subwoofer and surround speaker.
[57] In an aspect, the one or more primary audio signals can be associated with dialogue information.
[58] In an aspect, the control unit can be configured to: filter, by using a filtering unit, the plurality of down-mixed audio signals to form a soundtrack data stream; and route, by using a routing unit, the soundtrack data stream, via the plurality of output channels, to the plurality of speakers, respectively, placed at predetermined positions relative to a position of a listener, wherein, if any of the plurality of speakers gets damaged, remaining of the plurality of speakers is configured to provide seamless audio information to the listener.
[59] In an aspect, the filtering of the plurality of downmixed audio signals can include a band pass filtering of the plurality of downmixed audio signals.
[60] In an aspect, the plurality of output channels can include at least one of a low frequency channel, medium frequency channel and high frequency channel that can correspond to the plurality of input channels.
[61] In an aspect, the system can be implemented in movie theatres, cinema halls or in any other places.
[62] Another aspect of the present disclosure pertains to a device for providing redundancy to multi-channel audio to a set of speakers. The device includes one or more processors that can be operatively coupled with a memory, said memory storing device implemented instructions which when executed by the one or more processors, on receipt of an activation signal, to: receive, from an audio unit operatively coupled with the device, a plurality of audio signals from a corresponding plurality of input channels, based on a predetermined association of each of the plurality of the audio signals with a corresponding input channel; and down-mix the plurality of received audio signals based on any one or more primary audio signals out of the plurality of received audio signals, wherein the plurality of down-mixed audio signals each comprise at least the any one or more primary audio signals of the plurality of received audio signals. A plurality of output channels can be corresponding to the plurality of input channels, and the plurality of output channels can be operatively coupled with the one or more processors. Each output channel can be configured to transmit, from the one or more processors, at least one down-mixed audio signal. The plurality of output channels can be operatively coupled to a plurality of speakers and are configured to transmit the plurality of down-mixed audio signals to the plurality of speakers.
[63] In an aspect, the device can be operatively coupled to a switching unit, and the one or more processors can be configured to, upon activation by the switching unit, receive the activation signal.
[64] In an aspect, the plurality of input channels can include one or more audio channels, and wherein the one or more audio channels can be at least one of a centre channel, right channel and left channel.
[65] In an aspect, the one or more primary audio signals can be associated with dialogue information.
[66] In an aspect, the one or more processors can be configured to: filter, by using a filtering unit, the plurality of down-mixed audio signals to form a soundtrack data stream; and route, by using a routing unit, the soundtrack data stream, via the plurality of output channels, to the plurality of speakers, respectively, placed at predetermined positions relative to a position of a listener, wherein if any of the plurality of speakers gets damaged, remaining of the plurality of speakers can be configured to provide seamless audio information to the listener.
[67] In an aspect, the device can be implemented in movie theatres, cinema halls or in any other places.
[68] FIG. 1 illustrates an exemplary block diagram representation of a system for providing redundancy tomulti-channel audio information to a set of speakers in accordance with an embodiment of the present disclosure.
[69] According to an embodiment, the system 100 can include one or more processor(s) 102. The one or more processor(s) 102 can be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, logic circuitries, and/or any devices that manipulate data based on operational instructions. Among other capabilities, the one or more processor(s) 102 are configured to fetch and execute computer-readable instructions stored in a memory 104 of the system 100. The memory 104 can store one or more computer-readable instructions or routines, which can be fetched and executed to create or share the data units over a network service. The memory 104 can include any non-transitory storage device including, for example, volatile memory such as RAM, or non-volatile memory such as EPROM, flash memory, and the like.
[70] Various components /units of the proposed system 100 can be implemented as a combination of hardware and programming (for example, programmable instructions) to implement their one or more functionalities as elaborated further themselves or using processors 102. In examples described herein, such combinations of hardware and programming may be implemented in several different ways. For example, the programming for the units may be processor executable instructions stored on a non-transitory machine-readable storage medium and the hardware for units may include a processing resource (for example, one or more processors), to execute such instructions. In the present examples, the machine-readable storage medium may store instructions that, when executed by the processing resource, implements the various units. In such examples, thesystem 100 may include the machine-readable storage medium storing the instructions and the processing resource to execute the instructions, or the machine-readable storage medium may be separate but accessible to thesystem 100 and the processing resource. In other examples, the units may be implemented by electronic circuitry. A database 120may include data that is either stored or generated as a result of functionalities implemented by any of the other components /units of the proposed system 100.
[71] In an embodiment, the system 100 for providing redundancy to multi-channel audio to aplurality of speakers 116is disclosed. The system 100 can include: an audio unit 108; a control unit 106 that can be operatively coupled with the audio unit 108; a down-mixing unit 110; a routing unit 112; a filtering unit 114;a switching unit 118; database 120 and other units 122. In an exemplary embodiment, the filtering unit 114 is a crossover-filtering unit. The plurality of speakers 116 can be loudspeakers.
[72] The audio unit 108 can be configured to receive a plurality of audio signals from a corresponding plurality of input channels, based on a predetermined association of each of the plurality of the audio signals with a corresponding input channel.
[73] In an embodiment, the plurality of input channels can include one or more audio channels, and the one or more audio channels can be at least one of a centre channel, right channel and left channel.
AUDIO UNIT 108:
[74] Referring to FIG. 2, the audio unit108 can comprise a driver unit 16, a detection unit 20, and an alert unit22. The audio unit 108 can be connected to the control unit 106 and an acoustic output device, such as a speaker. The control unit 106 may be controllable by a user. Although in the present embodiment, the audio unit 108 and the control unit 106 are shown as separate units, the audio unit 108 may be integrated or arranged within the control unit 106.
[75] In the shown example, the driver unit 16 may be connected between the control unit 14 and the loudspeaker. The detection unit 20 may be connected to the driver unit 16. The alert unit 22 may be operatively coupled to the detection unit 20. The alert unit 22 may, furthermore, be connected to the control unit 106.After receiving the plurality of audio signals, the driver unit 16 may generate a plurality of second audio signals to drive the plurality of loudspeakers 116 to generate desired output signals. The audio signal can be an analogue audiosignal such as an electrical voltage or an electrical current with an amplitude corresponding to an amplitude of the acoustic signal. For example, the plurality of speakers 116 may comprise a coil connected to a membrane. By applying the audio signal, which in this example may be an electrical voltage, across the coil, the membrane (not shown) may be driven to oscillate in accordance with the analogue audio signal and thereby generate sound, namely, the acoustic signal, which may be heard by user.
[76] The detection unit 20 can be configured to generate a detection signal on positive detection of the plurality of audio signals. The detection signal can then be fed to the alert unit 22. In the event of the detection signal not being received by the alert unit say, within a certain period of time after receiving a request, the alert unit 22 can be configured to generate an alert signal in response to a lack of detection of the plurality of audio signals. For instance, the alert unit 22 may be arranged to generate the alert signal if it does not receive the detection signal within a certain period after receiving the request. In an exemplary embodiment, the audio unit 108 can be implemented in any other known manner as well.
[77] Referring to FIG. 1, the control unit 106 can be operable upon receipt of an activation signal.The control unit 106 can include one or more processors 102 operatively coupled with memory 104. The memory 104 can store instructions executable by the one or more processors 102 to: down-mix, by using mixing unit110,the plurality of received audio signals based on any one or more primary audio signals out of the plurality of received audio signals, wherein the plurality of downmixed audio signals can each include at least the any one or more primary audio signals.
[78] In an exemplary embodiment, the one or more primary audio signals can be associated with dialogue information. Generally, as implemented in movie theatres, cinema halls and other enclosures adapted for audiences to listen to sounds, one or more primary audio signals can be carried by the centre channels.
[79] A plurality of output channels corresponding to the plurality of input channels can be operatively coupled with the control unit 106, where each output channel can be configured to transmit, from the control unit 106, at least one downmixed audio signal. The plurality of output channels can be operatively coupled to the plurality of speakers 116 and can be configured to transmit the plurality of downmixed audio signals to the plurality of speakers 116.
MIXING UNIT 110:
[80] Referring to FIG. 3, the mixing unit 110 (hereinafter, also referred to as “downmixer”) receives the plurality of audio signals and downmixes the same to generate/produce a plurality of downmixed audio signals. The mixing unit 110 implements downmixingin a phase coherent manner such that it prevents phase cancellation and restoresintelligibility of dialogues by implementing a phase compensation unit in the mixing unit 110. The mixing unit creates a phase coherent downmix in consideration of different times of arrival of sound from the plurality of speakers 116.
[81] In an exemplary embodiment, the mixing unit 110 can be configured to receive audio signals from any or all of left channel, centre channel, right channel, subwoofer channel, left surround channel, right surround channel, left back surround channel and right back surround channel. After phase compensation, the signals carried by centre channel can be replicated in remaining channels.
[82] The downmixer 110 downmixes the plurality of audio signals by use of gain factors applied to each of the plurality of audio signals, i.e., a gain factor is applied to each audio signal, and then all the weighted audio signals are summed up to obtain the plurality of down mixed audio signals.
[83] In an exemplary embodiment, audio downmixing of a multi-channel audio program is performed in accordance with a predetermined formula, to collapse (downmix) a first set of channels of the program (N channels indicative of a first soundfield, where N is an integer) down to a second set of channels (M channels indicative of a downmixed soundfield, where M is an integer less than N) for playback by an available speaker array including M speakers (e.g., a speaker array including two speakers). During playback, after downmixing, the available speaker array emits sound indicative of the downmixed soundfield. Typically, downmixing of this type is included in the second set of channels (i.e., the downmix) to provide audio content of all the channels in the first set. A downmix matrix tries not only to match the physical mixing of the audio information, but to also convey the artistic intentions of the producer. There are several ways of generating downmix matrices, such as manually, by using generic acoustic knowledge about the role and position of the input and output speakers, manually, by using knowledge about the actual content and the artistic intention, and automatically, by using a software tool, which computes an approximation using the given output speakers.
[84] In an exemplary embodiment, various downmixing algorithms are implemented in downmixer 110. The algorithms can be at least one selected from group comprising a standard downmixing method (ITU-R BS.775-1), HRTF-based downmixing technique, HRTFCCS-based methodand other downmixing algorithms known in the art. The CCS technique has significantly improved the spatial impression, and its implementation in downmixing may significantly improve the spatial impression, minimize the crosstalk and recover spatial quality
[85] Referring to FIG. 1, the system 100 can include the switching unit 118 that can be operatively coupled to the control unit 106. The control unit 106 can be configured to, upon activation by the switching unit 118, receive the activation signal. The switching unit 118 can be activated either manually or automaticallyin the event of failure of any of the plurality of input channels and/or failure of any of the plurality of speakers 116.
[86] In an embodiment, the plurality of speakers 116 can be at least one of a main speaker, subwoofer, surround speaker or any other well-known speaker.
[87] In an embodiment, the control unit 106 can be configured to filter, by using the filtering unit 114, the plurality of downmixed audio signals to form a soundtrack data stream.
[88] The filtering of the plurality of downmixed audio signals can include a band pass filtering of the plurality of downmixed audio signals.
FILTERING UNIT 114:
[89] Referring to FIG. 4, the filtering unit 114 can include crossovers or cross overfilters that may include a pair of filters such as a high pass and a low pass filter. Each filter may have an amplitude response that may include a notch or null response at a frequency close to or in the region of the crossover frequency. A notch or null response, above the crossover frequency in the low pass filter and below the crossover frequency in the high pass filter, may provide a greatly increased or steeper roll off for each filter of the crossover for any order of filter. Notwithstanding the notch or null response, the amplitude responses of the pair of filters may be added to produce a combined output that is substantially flat or constant in amplitude at least across the region of the crossover frequency. Benefits of such an arrangement may include improved amplitude response and improved out of band signal attenuation close to the crossover frequency for each band.
[90] The low pass filter may include a first null response at a frequency in the region of and above the crossover frequency. The first null response may be provided by at least one complex conjugate pair of transmission zeros such that their imaginary parts lie in the stop band of the low pass transfer function within the crossoverregion. The high pass filter may include a second null response at a frequency in the region of and below the crossover frequency. The second null response may be provided by at least one complex conjugate pair of transmission zeros such that their imaginary parts lie in the stop band of the high pass transfer function within the crossover region.
[91] The filtering unit 114 may be realised via networks of any desired order depending upon the desired rate of roll off for the resultant crossover. The filtering unit 114 may be realised using passive, active or digital circuitry or combinations thereof, as known in the art. Combinations may include, but not be limited to an active low pass and passive high pass filter pair of any desired order, digital low pass and active high pass filter of any desired order, passive low pass and passive high pass filter of any desired order, digital low pass and digital high pass filter of any desired order and active low pass and digital high pass filter realisations.
[92] Further, the filtering unit 114 may be further realised wherein the filter response is produced with a combination of electrical and mechano-acoustic filtering as may be the case where the electroacoustic transducer and/or the associated acoustic enclosure realise part of the filter response. Crossoverfilters may be used to limit transfer bands in the individual loudspeakers in order to adjust the phase response in audio signals reproduced by the loudspeakers. Different types of filters (e.g., Butterworth, Bessel, Linkwitz-Riley, etc.) may be included within the system 100 to positively adjust the sound by changing phase transitions.
[93] As used herein, the term “crossover” refers to a filter bank that splits at least one of the pluralities of downmixed audio signals into at least one high band audio signal and at least onelow band audio signal. Thus, a crossover can generate a low band signal and a high band signal from a wideband electrical audio signal. If there are multipleinput signals, the crossover can generate a low band signal and a high band signal for each down-mixed audio signal. The filtering unit 114 can also include abeam former module that receives two or more low band signals from the crossover, one for each incoming microphone signal, and generates low band beam formed signals from the low band signals. The filtering unit 114 can also include a combiner module that combines the high band signals and the low band beam formed signals to generate modified wideband audio signals.
[94] In an exemplary embodiment, the filtering unit 114 can include an audio crossover that generates low band signalsand high band signals from the incoming wideband electrical audio signals. As used herein, the term “low band signal” refers to lower frequency components of a wideband electrical audiosignal and the term “high band signal” refers to higher frequency components of a wideband electrical audiosignal. As used herein, the term “lower frequency components” refers to frequency components of a wideband electrical audio signal that are less than a crossover frequency (fc) of the audio crossover, and the term “higher frequency components” refers to frequency components of a wideband electrical audio signal that are greater than or equal to the crossover frequency (fc) of the audio crossover.
[95] More specifically, in this embodiment, the crossover includes a first low-pass filter, a first high-pass filter, a second low-pass filter, and a second high-pass filter. The first low-pass filter generates a first low band signal with low frequency components of the first wideband electrical audio signal, and the second low-pass filtergenerates a second low band signal with low frequency components of the second wideband electrical audio signal. Each low-pass filter passes low-frequency band signals but attenuates (reduces the amplitude of) signals with frequencies higher than the cut-off frequency (i.e., the frequency characterizing a boundary between a passband and a stopband). Thus, low pass filtering removes the high band frequencies that cannot be properly beamformed, thereby resulting in good acoustic imaging in the low band.
[96] It will be appreciated by those skilled in the art that the low-pass and high-pass filters used in this particular implementation of the crossover are not limiting, and that other equivalent filter bank configurations could be used to implement the crossover such that it produces the same or very similar outputs based on the wideband electrical audio signals.
[97] Referring to FIG. 1, the control unit 106 can be configured to route, by using the routing unit 112, the soundtrack via the plurality of output channels, to the plurality of speakers 116 respectively, placed at predetermined positions relative to a position of a listener, wherein, if any of the plurality of speakers 116 gets damaged, remaining of the plurality of speakers 116 can be configured to provide seamless audio information to the listener.
ROUTING UNIT 112:
[98] In an exemplary embodiment, the routing unit 112 can receive a signal and can route that signal by transmitting it to only a part of the system 100. The routing unit 112 creates data isolation between circuits of the system 100 so that signals on one circuit do not necessarily appear on other circuits. The routing unit 112 includes a storage device that stores details of the units connected to each other and details of circuitsin the system 100. This information can be programmed into the storage device via a user interface comprising keypad and display on the routingunit 112 that can periodically refresh a routing network to determine which units are connected to the routing network and their location. Other methods of keeping the information in the storage device are possible. For example, each unit can be arranged such that when it is switched on at the mains, it may send identifying information to the routing unit 112 via the routing network. The system 100 has the advantages that there is no requirement of extra signal traffic of periodic refreshesand there is norequirement for any user input.
[99] In the system 100, data is communicated by way of Internet Protocol (IP) packets or datagrams using a variety of suitable upper-layer transport communication protocols. For example, packets may be encapsulated and communicated using Transmission Control Protocol (TCP)/Hypertext Transport Protocol (HTTP), User Datagram Protocol (UDP) protocol, and/or Stream Control Transmission Protocol (SCTP). It should be noted that the embodiments described herein are equally applicable to other devices that receive digital data for processing and communication to other devices, such as servers and routing devices.
[100] In an exemplary embodiment, the routing unit 112 can implement one or more routing protocols. An example of a routing protocol is Border Gateway Protocol (BGP), which is an inter-domain routing protocol used within the Internet to exchange IP address prefix and network layer reachability information between multiple domains and to distribute external IP address prefix information within any of the multiple domains. Other examples of inter-domain protocols include Interior Border Gateway Protocol (a type of BGP), Exterior Border Gateway Protocol (a type of BGP), and other inter-domain protocols.
[101] A Routing Protocol may gather and share the routing information that is used to maintain and update routing tables. The routing information may in turn be used to route a routed protocol to its final destination. A Routing Protocol may also be a formula used by routing unit 112 to determine the appropriate path onto which data should be forwarded and may specify how routing unit 112 reports change and sharean information with other routing units or routers in a network that they can reach.Unlike static routing where all routing decisions may be required to be predetermined and remain static, a routing protocol may allow the network to dynamically adjust to changing conditions. This may be accomplished via an announcement by the routing protocol to routing unit 112 that may be updated appropriately.
[102] Referring to FIG. 1, the plurality of output channels can be at least one of a low frequency channel, medium frequency channel and high frequency channel corresponding to the plurality of input channels.
[103] In an exemplary embodiment, the system 100 can be implemented in cinema halls, movie theatres or in any other surround sound systems. In case of failure of at least one of a centre channel, centre amplifier, centre channel speaker or any other audio component associated with the surround sound system, the system 100 can provide redundancy to audio information (such as dialogues, background music or any other soundtrack information), instantaneously, without degrading sound quality of the audio information.
[104] In an exemplary embodiment, the plurality of audio signals are mixed in predefined ratios such that the listener can get a perception that dialogues are coming from a centre channel even if at least one of the centre channels,speaker andamplifier associated with the centre channel fails.
[105] FIG. 5 illustrates an exemplary block diagram representation of a device for providing redundancy tomulti-channel audio information to a set of speakers in accordance with an embodiment of the present disclosure.
[106] The device 500 can include one or more processors 502 that can be operatively coupled with memory 504; transceiver unit 506, mixing unit 508; filtering unit 510; routing unit 512; and switching unit 514.
[107] The memory 504 storingdevice implemented instructions which when executedby the one or more processors 502, on receipt of an activation signal, toreceive, by using transceiver unit 506, from an audio unit operatively coupled with the device 500, a plurality of audio signals from a corresponding plurality of input channels, based on a predetermined association of each of the plurality of the audio signals with a corresponding input channel. The plurality of input channels comprises one or more audio channels, wherein the one or more audio channels are at least one of a centre channel, right channel and left channel.
[108] The one or more processors 502 can be configured to downmix, by using the mixing unit 508,the plurality of received audio signals based on any one or more primary audio signals out of the plurality of received audio signals, wherein the plurality of downmixed audio signals each include at least the any one or more primary audio signals. The one or more primary audio signals can be associated with dialogue information.
[109] A plurality of output channels corresponding to the plurality of input channels can be operatively coupled with the one or more processors 502, and each output channel can be configured to transmit, from the one or more processors 502, at least one down-mixed audio signal. The plurality of output channels can be operatively coupled to a plurality of speakers and are configured to transmit the plurality of downmixed audio signals to the plurality of speakers.
[110] In an embodiment, the one or more processors 502 can be configured to receive the activation signal upon activation by the switching unit 514.
[111] In an embodiment, the one or more processors 502 can be configured tofilter, by using filtering unit 510, the plurality of downmixed audio signals to form a soundtrack data stream.
[112] In an embodiment, the one or more processors can be configured to route, by using routing unit 512, the soundtrack data stream via the plurality of output channels to the plurality of speakers respectively, placed at predetermined positions relative to a position of the listener, wherein if any of the plurality of speakers gets damaged, remaining of the plurality of speakers can be configured to provide seamlessredundancy to audio information to the listener.
[113] In an embodiment, the filtering of the plurality of downmixed audio signals can include a band pass filtering of the plurality of downmixed audio signals. The plurality of output channels can include at least one of a low frequency channel, medium frequency channel and high frequency channel corresponding to the plurality of input channels.
[114] In an exemplary embodiment, the mixing unit 508, filtering unit 510 and routing unit 512 can be same as mixing unit 110, filtering unit 114 and routing unit 112 respectively.
[115] FIG. 6 illustrates an exemplary representation of typical layout of speakers and channels in a cinema in accordance with an embodiment of the present disclosure.
[116] FIG. 7 illustrates an exemplary side elevation view representation of speaker placement in a cinema in accordance with an embodiment of the present disclosure.
[117] FIG. 8 illustrates an exemplary signal flow of audio in a cinema equipped with a 5.1 surround audio system in accordance with an embodiment of the present disclosure.
[118] FIG. 9 illustrates a schematic layout of audio signal flow in accordance with an embodiment of the present disclosure.
[119] As shown in FIG. 9, down mix unit can receive input audio signals from left channel, centre channel, right channel, subwoofer channel, left surround channel and right surround channel. The down mix unit can be activated by receiving activation signal from emergency switch (EMG SWITCH). After downmixing, audio signals are transmitted, via centre channel, right channel and left channel (at output side), to main speakers in high frequency band, low frequency band and medium frequency band. Output channels of down mix unit can include a subwoofer channel that transmits audio signals to bass management unit and finally to the subwoofers.The output channels further includes left surround channel and right surround channel that are fed to surround speakers.
[120] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skillin the art.
ADVANTAGES OF THE INVENTION
[121] The present inventionprovides a system and device for providing redundancy toor seamless multi-channel audio information (such as playback information) to electroacoustic transducers such as speakers.
[122] The present inventionprovides a simple and cost-effective system and device for preventing movie show cancellations in a movie theatre in case of failure of centre channel or speaker associated with the centre channel.
[123] The present inventionprovides a reliable and fast system and device for providing redundancy to audio playback such as dialogues, background music etc. with enhanced sustainability and quality.
[124] The present inventionprovides a precise, accurate and efficient system and device for providing localized audio playback or reproduction in a seamless manner without causing any phase cancellation.
[125] The present inventionprovides a smart system and device for providing localized audio playback with minimum degradation to soundtrack during failure of centre channel, amplifier and/or speaker associated with the centre channel.
[126] The present inventionprovidesa system and device to provide sufficient time for sound engineers to solve a problem in case of failure of centre channel amplifier or speaker either completely or partially.