Method and apparatus for audio processing for classifying multi-channel audio signals

Abstract

Provided is an electronic device configured to: acquire playback layout information related to sound playback using multiple channels; acquire a first sound signal related to a sound played through a low frequency effect (LFE) channel among the multiple channels; acquire a second sound signal different from the first sound signal by modifying the first sound signal on the basis of the playback layout information; and transfer the second sound signal to an external device.

Description

Audio processing method and device for classifying multi-channel audio signals

[0001] The present disclosure relates to an audio processing method and an audio processing device for classifying multi-channel audio signals. More specifically, the present disclosure relates to an audio processing method and an audio processing device for classifying audio signals having the same number of channels but reproduced through different channel layouts. The present disclosure relates to an audio processing method and an audio processing device for preprocessing an input multi-channel audio signal to distinguish the channel layout from which the audio signal is output. The present disclosure relates to an audio processing method and an audio processing device for outputting a preprocessed multi-channel audio signal to distinguish the channel layout from which the audio signal is output.

[0002] Conventional channel layouts for 3D audio signals place channels in an omni-directional manner centered on the listener. With the expansion of Over-The-Top (OTT) services, increasing TV resolution, and larger screens on electronic devices such as tablets, viewers are increasingly seeking to experience immersive sound, similar to theater-quality content, in their home environments. Therefore, there is a need to process audio signals in a 3D audio channel layout (a 3D audio channel layout in front of the listener), in which channels are placed in front of the listener, taking into account the sound representation of on-screen objects (or sound sources).

[0003] A 3D audio channel layout can configure an audio system that includes height channels that provide sound along the vertical direction. For example, even within a channel layout with eight channels, a 5.1.2 channel layout that additionally supports vertical sound and a 7.1.0 channel layout that only supports horizontal sound are possible.

[0004] However, some audio systems may not have the channel layout to reproduce sound based on a 5.1.2 channel layout. Furthermore, some audio systems only receive signals corresponding to 8 channels, and do not receive signals that distinguish between 5.1.2 and 7.1.0 channels. Therefore, the audio system needs to distinguish the channel layout from the received audio signal. In other words, the audio signal transmitted to the audio system needs to be preprocessed to distinguish the channel layout.

[0005] An electronic device according to an embodiment of the present disclosure may include at least one memory configured to store one or more instructions and at least one processor. By having the at least one processor execute a program stored in the memory or one or more instructions, the electronic device may obtain playback layout information related to sound reproduction using multiple channels. The electronic device may obtain a first audio signal related to sound reproduced through an LFE (Low Frequency Effect) channel among the multiple channels. The electronic device may obtain a second audio signal different from the first audio signal by modifying the first audio signal based on the playback layout information. The electronic device may transmit the second audio signal to an external device.

[0006] An electronic device according to an embodiment of the present disclosure may include at least one memory configured to store one or more instructions and at least one processor. The electronic device may receive an LFE (Low Frequency Effect) channel audio signal regarding sound reproduced through an LFE channel among a plurality of channels by the at least one processor executing a program stored in the memory or one or more instructions. The electronic device may determine a channel layout for reproducing the sound based on a signal obtained by applying the LFE channel audio signal to one or more band pass filters. The electronic device may output sound according to the signal obtained by applying the LFE channel audio signal to a low pass filter.

[0007] A method for processing an audio signal by an electronic device according to an embodiment of the present disclosure may include a step of obtaining playback layout information related to audio reproduction using a plurality of channels. The method may include a step of obtaining a first audio signal related to audio reproduced through a low frequency effect (LFE) channel among the plurality of channels. The method may include a step of obtaining a second audio signal different from the first audio signal by modifying the first audio signal based on the playback layout information. The method may include a step of transmitting the second audio signal from the electronic device to an external device.

[0008] A method for an electronic device to output an audio signal according to an embodiment of the present disclosure may include receiving an LFE (Low Frequency Effect) channel audio signal regarding audio reproduced through an LFE channel among a plurality of channels. The method may include a step of determining a channel layout for reproducing audio based on a signal obtained by applying the LFE channel audio signal to one or more band pass filters. The method may include a step of outputting audio according to a signal obtained by applying the LFE channel audio signal to a low pass filter.

[0009] According to one embodiment of the present disclosure, a computer-readable recording medium may record a program executable by at least one processor to perform at least one of the embodiments of the disclosed method on a computer.

[0010] The features of the present disclosure will become more apparent by describing the embodiments in detail with reference to the attached drawings.

[0011] FIG. 1 is a conceptual diagram illustrating a system for classifying a multi-channel audio signal according to one embodiment of the present disclosure.

[0012] FIG. 2 is a flowchart illustrating an audio processing method for classifying a multi-channel audio signal according to an embodiment of the present disclosure.

[0013] FIG. 3 is a flowchart illustrating a method for determining whether to modify an acoustic signal depending on whether there is a height channel according to an embodiment of the present disclosure.

[0014] FIG. 4 is a flowchart illustrating a method for determining an acoustic signal to be transmitted to an external device according to one embodiment of the present disclosure.

[0015] FIG. 5A is a conceptual diagram illustrating an example of a method for classifying a multi-channel audio signal according to an embodiment of the present disclosure, in which signals are transmitted between each component.

[0016] FIG. 5b is a conceptual diagram illustrating an example of a method for classifying a multi-channel audio signal according to an embodiment of the present disclosure, in which signals are transmitted between each component.

[0017] FIG. 6A is a graph for explaining a first sound signal regarding sound reproduced through an LFE (Low Frequency Effect) channel according to one embodiment of the present disclosure.

[0018] FIG. 6b is a graph for explaining a second acoustic signal different from a first acoustic signal according to one embodiment of the present disclosure.

[0019] FIG. 7 is a conceptual diagram illustrating a method for reproducing sound when an audio system is not equipped with a height channel, according to one embodiment of the present disclosure.

[0020] FIG. 8 is a conceptual diagram illustrating a system for classifying a multi-channel audio signal according to an embodiment of the present disclosure.

[0021] FIG. 9 is a flowchart illustrating a method for classifying a multi-channel audio signal according to an embodiment of the present disclosure.

[0022] FIG. 10 is a flowchart illustrating a method for classifying a multi-channel audio signal according to an embodiment of the present disclosure.

[0023] FIG. 11 is a flowchart illustrating a method for reproducing sound before it is transformed by filtering the sound signal, according to one embodiment of the present disclosure.

[0024] FIG. 12 is a conceptual diagram illustrating a system for classifying a multi-channel audio signal according to an embodiment of the present disclosure.

[0025] FIG. 13 is a flowchart illustrating an audio processing method for classifying a multi-channel audio signal according to an embodiment of the present disclosure.

[0026] FIG. 14 is a flowchart illustrating a method for classifying a multi-channel audio signal according to an embodiment of the present disclosure.

[0027] FIG. 15A is a graph for explaining a first sound signal regarding sound reproduced through an LFE (Low Frequency Effect) channel according to one embodiment of the present disclosure.

[0028] FIG. 15b is a graph for explaining a second acoustic signal different from a first acoustic signal according to one embodiment of the present disclosure.

[0029] FIG. 16 is a flowchart illustrating a method for generating a second acoustic signal by preprocessing a first acoustic signal according to an embodiment of the present disclosure.

[0030] FIG. 17 is a flowchart illustrating a method for recovering a first acoustic signal prior to preprocessing by post-processing a second acoustic signal according to an embodiment of the present disclosure.

[0031] FIG. 18 is a flowchart illustrating a method for interpreting multiple audio signals by post-processing discontinuities between two input audio signals, according to one embodiment of the present disclosure.

[0032] FIG. 19 is a diagram for explaining the configuration of an audio processing device for processing a multi-channel audio signal according to one embodiment of the present disclosure.

[0033] FIG. 20 is a drawing for explaining the configuration of an audio output device for outputting a multi-channel audio signal according to one embodiment of the present disclosure.

[0034] The terms used in this disclosure have been selected from widely used, current terms, taking into account the functions of the disclosure. However, these terms may vary depending on the intentions of those skilled in the art, precedents, the emergence of new technologies, etc. Furthermore, in certain cases, terms may be arbitrarily selected by the applicant, and in such cases, their meanings will be described in detail in the relevant description of the invention. Therefore, the terms used in this disclosure should not be defined simply as names, but rather based on the meanings of the terms and the overall content of the disclosure.

[0035] Singular expressions may include plural expressions unless the context clearly indicates otherwise. Terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art described herein. Furthermore, terms containing ordinal numbers, such as "first" or "second," used herein may be used to describe various components, but such components should not be limited by such terms. Such terms are used solely to distinguish one component from another.

[0036] When a part of the specification is said to "include" a component, this does not exclude other components, but rather implies the inclusion of other components, unless otherwise specifically stated. Furthermore, terms such as "part," "module," etc., used throughout the specification refer to a unit that processes at least one function or operation, which may be implemented in hardware, software, or a combination of hardware and software.

[0037] Below, embodiments are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present disclosure. However, the present disclosure may be implemented in various different forms and is not limited to the embodiments described herein. In addition, in the drawings, parts irrelevant to the description are omitted for clarity of description of the present disclosure, and similar parts are designated with similar reference numerals throughout the specification.

[0038] In this specification, an 'audio processing system' means a system including any device that inputs an audio signal, processes the input audio signal, and any device that receives and outputs the processed audio signal. For example, the 'audio processing system' may include a 'communication module', an 'audio processing device', and / or an 'audio output device'.

[0039] In this specification, the term 'electronic device' may include the meaning of 'audio processing device', 'audio output device' or 'audio processing system' including an audio processing device and an audio output device.

[0040] In this specification, a 'multi-channel audio signal' may mean an audio signal of n channels (where n is an integer greater than or equal to 1). A 'mono-channel audio signal' may be a one-dimensional audio signal, or a 'stereo-channel audio signal' may be a two-dimensional audio signal, and a 'multi-channel audio signal' may include not only a 'mono-channel audio signal' and a 'stereo-channel audio signal', but also a three-dimensional audio signal.

[0041] A '3D audio signal' can mean an audio signal that can determine the distribution of sound and the location of sound sources in a 3D space.

[0042] In this specification, the term "channel (speaker) layout" may refer to a combination of at least one channel and may specify the spatial arrangement of the channels (speakers). The channel here is a channel through which audio signals are actually output, and thus may be referred to as a presentation channel.

[0043] For example, the channel layout may be an XYZ channel layout, where X represents the number of surround channels, Y represents the number of subwoofer channels, and Z represents the number of height channels. By the 'channel layout', the spatial locations of each of the surround channels / subwoofer channels / height channels can be specified.

[0044] Examples of 'channel (speaker) layouts' include, but are not limited to, 1.0.0 channel (mono channel) layout, 2.0.0 channel (stereo channel) layout, 5.1.0 channel layout, 5.1.2 channel layout, 5.1.4 channel layout, 7.1.0 layout, 7.1.2 layout, and 3.1.2 channel layout.

[0045] The names of the channels specified by the 'channel (speaker) layout' may vary, but for the sake of convenience of explanation, they will be unified.

[0046] Based on the spatial location of each channel, the channels in the 'channel (speaker) layout' can be named as follows.

[0047] For example, the first surround channel in a 1.0.0 channel layout may be named the Mono Channel. The first surround channel in a 2.0.0 channel layout may be named the L2 channel, and the second surround channel may be named the R2 channel.

[0048] Here, "L" indicates that the channel is located to the left (Left) from the listener's perspective, and "R" indicates that the channel is located to the right (Right) from the listener's perspective. "2" indicates that it is a surround channel when there are two surround channels in total. "L" can also be referred to as "FL (Front-Left)", and "R" can also be referred to as "FR (Front-Right)".

[0049] In a 5.1.0 channel layout, the first surround channel may be named the L5 channel, the second surround channel may be named the R5 channel, the third surround channel may be named the C channel, the fourth surround channel may be named the Ls5 channel, and the fifth surround channel may be named the Rs5 channel. Here, "C" indicates that the channel is located at the center (center) with respect to the listener. "s" indicates that the channel is located on the side (side). "L5", "R5", "Ls5", and "Rs5" may also be named "L", "R", "SL", and "SR", respectively.

[0050] The first subwoofer channel in a 5.1.0 channel layout may be named the LFE channel. Here, LFE may stand for Low Frequency Effect. In other words, the LFE channel may be a channel for outputting low-frequency sound effects.

[0051] The surround channels in a 5.1.2 channel layout and a 5.1.4 channel layout may have the same name as the surround channels in a 5.1.0 channel layout. Similarly, the subwoofer channels in a 5.1.2 channel layout and a 5.1.4 channel layout may have the same name as the subwoofer channels in a 5.1.0 channel layout.

[0052] 5.1.2 The first height channel of the channel layout may be named Hl5, where H represents the height channel. The second height channel may be named Hr5. "Hl5" and "Hr5" may also be referred to as "HFL (High-Front-Left)" and "HFR (High-Front-Right)", respectively.

[0053] Meanwhile, the first height channel in a 5.1.4 channel layout may be named Hfl channel, the second height channel may be named Hfr channel, the third height channel may be named Hbl channel, and the fourth height channel may be named Hbr channel. Here, f indicates a front channel centered on the listener, and b indicates a back channel.

[0054] In a 7.1.0 channel layout, the first surround channel may be referred to as the L channel, the second surround channel as the R channel, the third surround channel as the C channel, the fourth surround channel as the Ls channel, the fifth surround channel as the Rs channel, the sixth surround channel as the Lb channel, and the seventh surround channel as the Rb channel. "Ls", "Rs", "Lb", and "Rb" may also be referred to as "SL", "SR", "BL", and "BR", respectively.

[0055] The surround channels in a 7.1.2 channel layout and a 7.1.4 channel layout may have the same name as the surround channels in a 7.1.0 channel layout. Similarly, the subwoofer channels in a 7.1.2 channel layout and a 7.1.4 channel layout may have the same name as the subwoofer channels in a 7.1.0 channel layout.

[0056] 7.1.2 The first height channel of the channel layout may be named the Hl7 channel, and the second height channel may be named the Hr7 channel. "Hl7" and "Hr7" may also be referred to as "HFL (High-Front-Left)" and "HFR (High-Front-Right)", respectively.

[0057] 7.1.4 The first height channel of the channel layout may be named Hfl channel, the second height channel may be named Hfr channel, the third height channel may be named Hbl channel, and the fourth height channel may be named Hbr channel.

[0058] The first surround channel of the 3.1.2 channel may be named the L3 channel, the second surround channel may be named the R3 channel, and the third surround channel may be named the C channel. The first subwoofer channel of the 3.1.2 channel may be named the LFE channel. The first height channel of the 3.1.2 channel may be named the Hl3 channel, and the second height channel may be named the Hr3 channel.

[0059] Here, some channels are named differently depending on the channel layout, but may represent the same channel. For example, the Hl5 channel and the Hl7 channel may be the same channel. Similarly, the Hr5 channel and the Hr7 channel may be the same channel.

[0060] Meanwhile, various channel names may be used without being limited to the names of the channels described above.

[0061] The names of the channels in the channel layout for the aforementioned layout are summarized in Table 1 below.

[0062] Channel layout Channel names 1.0.0 Mono 2.0.0 L2 / R2 5.1.0 L5 / C / R5 / Ls5 / Rs5 / LFE 5.1.2 L5 / C / R5 / Ls5 / Rs5 / Hl5 / Hr5 / LFE 5.1.4 L5 / C / R5 / Ls5 / Rs5 / Hfl / Hfr / Hbl / Hbr / LFE 7.1.0 L / C / R / Ls / Rs / Lb / Rb / LFE 7.1.2 L / C / R / Ls / Rs / Lb / Rb / Hl7 / Hr7 / LFE 7.1.4 L / C / R / Ls / Rs / Lb / Rb / Hfl / Hfr / Hbl / Hbr / LFE 3.1.2 L3 / C / R3 / Hl3 / Hr3 / LFE

[0063] In this specification, 'up-mixing' may mean an operation in which the number of display channels of an output audio signal increases compared to the number of display channels of an input audio signal through de-mixing. In this specification, 'de-mixing' may mean one of the mixing operations in which an audio signal of a specific channel is separated from an audio signal in which audio signals of various channels are mixed (i.e., an audio signal of a mixed channel). In this case, 'de-mixing' may be implemented by an operation using a 'demixing matrix' (or a 'downmixing matrix' corresponding thereto), and the 'demixing matrix' may include at least one 'demixing weight parameter' (or a 'downmixing weight parameter' corresponding thereto) as a coefficient of the demixing matrix (or a 'downmixing matrix' corresponding thereto). The 'demixing weight parameter' may also be referred to as a 'demixing parameter', and the 'downmixing weight parameter' may also be referred to as a 'downmixing parameter'. Alternatively, 'demixing' may be implemented as a mathematical operation based on a portion of a 'demixing matrix' (or a corresponding 'downmixing matrix'), but is not limited thereto, and may be implemented in various ways. As mentioned above, 'demixing' may be related to 'upmixing'.

[0064] 'Mixing' refers to any operation that generates an audio signal of a new channel (i.e., a mixed channel) by multiplying each audio signal of multiple channels by its corresponding weight and adding the respective values ​​obtained (i.e., mixing the audio signals of multiple channels).

[0065] 'Mixing' can be divided into 'mixing' in the narrow sense performed in an audio encoding device and 'demixing' performed in an audio decoding device.

[0066] The 'mixing' performed in the audio encoding device can be implemented as an operation using a '(down)mixing matrix', and the '(down)mixing matrix' can include at least one '(down)mixing weight parameter' as a coefficient of the '(down)mixing matrix'. Alternatively, the '(down)mixing' can be implemented as a mathematical operation based on a part of the '(down)mixing matrix', and is not limited thereto and can be implemented in various ways.

[0067] In this specification, 'down-mixing' may mean an operation in which the number of display channels of an output audio signal is reduced compared to the number of display channels of an input audio signal through mixing.

[0068] FIG. 1 is a conceptual diagram illustrating a system for classifying a multi-channel audio signal according to one embodiment of the present disclosure.

[0069] Referring to FIG. 1, an audio processing system (1000) may include an audio processing device (100), a communication module (200), and an audio output device (300).

[0070] An audio processing device (100) can process multi-channel audio signals. The audio processing device (100) can acquire multi-channel audio signals and transform audio signals of some channels among the multi-channel audio signals. The audio processing device (100) can transmit the transformed audio signals to an audio output device (300) via a communication module (200).

[0071] 1. Operation of audio processing device (100)

[0072] In one embodiment, the audio processing device (100) may include at least one memory and at least one separate processor, and operations performed by the audio processing device (100) may be performed by at least one processor. The audio processing device (100) may perform each operation by having at least one processor execute a program or instruction stored in at least one memory. The audio processing device (100) may be implemented as a device capable of audio processing, such as a server, TV, camera, mobile phone, tablet PC, or laptop.

[0073] In one embodiment, the audio processing device (100) can obtain an audio bitstream (10) and playback layout information (130).

[0074] The audio bitstream (10) may be an audio signal obtained by encoding a multi-channel audio signal. The audio processing device (100) may obtain the audio bitstream (10) from an external device. For example, the audio processing device (100) may obtain the audio bitstream (10) from a server providing a streaming service (e.g., an over-the-top (OTT) service).

[0075] The playback layout information (130) may include information related to sound reproduction using multiple channels. The playback layout information (130) may include information regarding the arrangement and configuration of multiple channels for reproducing sound.

[0076] The playback layout information (130) may be transmitted from a server that provides a streaming service together with the audio bitstream (10), and the playback layout information (130) may correspond to the audio bitstream (10). The playback layout information (130) may include information on the arrangement and configuration of multiple channels for reproducing the audio of the audio bitstream (10). For example, if the audio bitstream (10) is to be reproduced in 5.1.2 channels, the playback layout information (130) may include information specifying the 5.1.2 channel layout.

[0077] In one embodiment, the audio processing device (100) may include an audio decoder (120). The audio decoder (120) may receive an audio bitstream (10). The audio decoder (120) may convert the audio bitstream (10) into a form that can be played back as audio by decoding the audio bitstream (10). The audio decoder (120) may classify audio corresponding to each channel. The audio decoder (120) may restore a multi-channel audio signal by using compressed audio signals of independent channels received from the audio bitstream (10).

[0078] For example, the audio decoder (120) can decode the audio bitstream (10) into a PCM (Pulse Code Modulation) format. The audio decoder (120) can decode the audio bitstream (10) and transmit audio signals of various layouts obtained to an external device.

[0079] As illustrated in FIG. 1, an audio decoder (120) can obtain a multi-channel audio signal (140) by decoding an audio bitstream (10). An audio processing device (100) can obtain a multi-channel audio signal (140) by inputting an audio bitstream (10) into the audio decoder (120).

[0080] A multi-channel audio signal (140) may include audio signals according to various channel layouts. In FIG. 1, an 8-channel audio signal is described as an example, but the number of channels is not limited thereto.

[0081] The multi-channel audio signal (140) may include an 8-channel audio signal. The multi-channel audio signal (140) may include an LFE channel audio signal (141) and a 7-channel audio signal (142). The LFE channel audio signal (141) may be a signal regarding sound reproduced through the LFE channel among the 8 channels. The 7-channel audio signal (142) may be signals regarding each sound reproduced through the remaining 7 channels excluding the LFE channel among the 8 channels.

[0082] For reference, each channel audio signal among the 7-channel audio signals (142) is treated equally and is therefore represented as one block in Fig. 1.

[0083] The 8 channels may include an LFE channel. The 8 channels may further include 7 channels other than the LFE channel. The layout of the 7 channels other than the LFE channel may vary and is simply expressed and described as 7 channels. However, the present disclosure is not limited thereto. For example, the layout of the 7 channels other than the LFE channel may include a 5.0.2 channel layout or a 7.0.0 channel layout. In other words, the channel layout may be composed of 5 surround channels and 2 height channels, or may be composed of 7 surround channels.

[0084] In one embodiment, the LFE channel audio signal (141) may include an audio signal transmitted to an LFE channel that outputs low-frequency sound effects. The LFE channel audio signal (141) may include an audio signal corresponding to an LFE channel that outputs low-frequency sound effects. The LFE channel audio signal (141) may include an audio signal in a frequency band that can be played back through, for example, a subwoofer speaker.

[0085] In one embodiment, the audio processing device (100) can modify the LFE channel audio signal (141) based on the playback layout information (130). The audio processing device (100) can perform an operation of adding a preset signal (150) to the LFE channel audio signal (141). The audio processing device (100) can determine whether to modify the LFE channel audio signal (141) based on the playback layout information (130).

[0086] In step S10, the audio processing device (100) can obtain whether a height channel is required for sound reproduction according to the sound bitstream (10) based on the reproduction layout information (130). If a height channel is required, the audio processing device (100) can add a preset signal (150) to the LFE channel audio signal (141). If a height channel is not required, the audio processing device (100) can not add a preset signal (150) to the LFE channel audio signal (141).

[0087] In one embodiment, the preset signal (150) may include a signal having a high frequency so as to be distinguished from the frequency of the LFE channel. The preset signal (150) may be a signal having a high frequency in a higher band than the LFE channel audio signal (141). The frequency range of the preset signal (150) is not limited to the present disclosure and may be set to be distinguished from the frequency of the LFE channel. For example, the frequency range of the preset signal (150) and the frequency range of the LFE channel audio signal (141) may not overlap.

[0088] The audio processing device (100) can transmit an unmodified LFE channel audio signal or a modified LFE channel audio signal to the audio output device (300) through the communication module (200) according to the reproduction layout information (130). The audio output device (300) can obtain, based on the received audio signal, whether a height channel is required for sound reproduction according to the audio bitstream (10). The audio output device (300) can reproduce sound through an appropriate channel layout based on whether a height channel is required.

[0089] In the present disclosure, the first audio signal may refer to a signal regarding audio reproduced through an LFE channel. The first audio signal may refer to an unmodified LFE channel audio signal (141), and may refer to an LFE channel audio signal (141) to which the preset signal (150) of FIG. 1 is not added or before it is added.

[0090] In the present disclosure, the second audio signal refers to a modified LFE channel audio signal. The second audio signal may refer to an LFE channel audio signal modified by adding the preset signal (150) of FIG. 1 to the LFE channel audio signal (141).

[0091] For example, the audio processing device (100) can transmit a first audio signal or a second audio signal to the audio output device (300) depending on whether a height channel is required. The audio output device (300) can reproduce sound through an appropriate channel layout by distinguishing between the first audio signal or the second audio signal.

[0092] 2. Operation of the communication module (200)

[0093] In one embodiment, the communication module (200) may include an LFE transport (210) and a 7-channel transport (220). The LFE transport (210) may be configured to transmit a signal regarding sound reproduced through an LFE channel. The 7-channel transport (220) may be configured to transmit a signal regarding sound reproduced through 7 channels excluding the LFE channel.

[0094] The communication module (200) may be, for example, an HDMI (High-Definition Multimedia Interface) that simultaneously transmits digital video and audio signals.

[0095] 3. Operation of audio output device (300)

[0096] The audio output device (300) can process a modified multi-channel audio signal and output the processed multi-channel audio signal. The audio output device (300) can obtain a multi-channel audio signal modified by the audio processing device (100) or an unmodified multi-channel audio signal through the communication module (200). The audio output device (300) can determine whether a height channel is required from the unmodified multi-channel audio signal or the modified multi-channel audio signal, and can output sound based on the required channel layout.

[0097] In one embodiment, the audio output device (300) may include at least one memory and at least one separate processor, and the operations performed by the audio output device (300) may be performed by at least one processor. The audio output device (300) may perform each operation by having the processor execute instructions or programs stored in at least one memory.

[0098] In one embodiment, the audio output device (300) may include a low-pass filter (311) and a band-pass filter (312). The low-pass filter (311) and the band-pass filter (312) refer to filters that only pass signals between specific frequencies. The frequency bands of signals passed by the low-pass filter (311) and the band-pass filter (312) may be different. The low-pass filter (311) may pass signals in a relatively low frequency band, and the band-pass filter (312) may pass signals in a relatively high frequency band. For example, the frequency bands of signals passed by the low-pass filter (311) and the band-pass filter (312) may not overlap each other.

[0099] For example, the low-pass filter (311) can pass signals in a frequency band below 400 Hz. For example, the band-pass filter (312) can pass signals in a frequency band from 9 kHz to 15 kHz. However, the frequency bands described herein are merely examples and do not limit the present disclosure.

[0100] In one embodiment, the audio output device (300) can receive a multi-channel audio signal (140) through the communication module (200).

[0101] Specifically, among the multi-channel audio signals (140), the 7-channel audio signal (142) can be obtained by the audio output device (300) without being modified. Among the multi-channel audio signals (140), the LFE channel audio signal (141) can be obtained by the audio output device (300) as a modified LFE channel audio signal according to predetermined conditions, or as an unmodified LFE channel audio signal. When sound reproduction through the height channel is required based on the reproduction layout information (130), the modified LFE channel audio signal can be obtained by the audio output device (300). When sound reproduction through the height channel is not required based on the reproduction layout information (130), the unmodified LFE channel audio signal can be obtained by the audio output device (300).

[0102] 3.1. Application of low pass filter (311) in audio output device (300)

[0103] In one embodiment, the audio output device (300) can filter the LFE channel audio signal modified by the audio processing device (100) or the LFE channel audio signal not modified by the audio processing device (100) through a low pass filter (311).

[0104] The modified LFE channel audio signal may be an audio signal to which a preset signal (150) is added. The preset signal (150) may be blocked by a low pass filter (311), and the audio output device (300) may restore the LFE channel audio signal (141) to its state before being modified by applying the modified LFE channel audio signal to the low pass filter (311).

[0105] The unmodified LFE channel audio signal may refer to the LFE channel audio signal (141) decoded by the audio decoder (120). The audio output device (300) may obtain the LFE channel audio signal (141) through the communication module (200). The unmodified LFE channel audio signal may be an audio signal to which a preset signal (150) is not added. The audio output device (300) may obtain the LFE channel audio signal (141) by applying the unmodified LFE channel audio signal to the low pass filter (311). Since the LFE channel audio signal (141) is passed by the low pass filter (311), the unmodified LFE channel audio signal before being filtered by the low pass filter (311) and the unmodified LFE channel audio signal after being filtered by the low pass filter (311) may be the same.

[0106] The audio output device (300) can consistently obtain the LFE channel audio signal (141) by applying the modified LFE channel audio signal or the unmodified LFE channel audio signal to the low pass filter (311). If the preset signal (150) is added to the LFE channel audio signal (141) and transmitted to the audio output device (300), the audio output device (300) can selectively remove the preset signal (150) through the low pass filter (311).

[0107] The audio output device (300) can output sound according to the LFE channel audio signal (141) through the LFE output port (321). The LFE channel audio signal (141) can be output through the LFE channel. The audio output device (300) can output sound according to a signal obtained by applying the LFE channel audio signal (141) to a low pass filter (311).

[0108] 3.2. Application of a band pass filter (312) in an audio output device (300)

[0109] In one embodiment, the audio output device (300) can filter the LFE channel audio signal modified by the audio processing device (100) or the LFE channel audio signal not modified by the audio processing device (100) through a band pass filter (312).

[0110] In step S20, the audio output device (300) according to one embodiment can determine whether a preset signal (150) is added based on an LFE channel audio signal filtered by a band pass filter (312).

[0111] The modified LFE channel audio signal may be an audio signal to which a preset signal (150) is added. The modified LFE channel audio signal may be a combination of the LFE channel audio signal (141) and the preset signal (150). The preset signal (150) may be passed through the band pass filter (312). The LFE channel audio signal (141) may be blocked by the band pass filter (312). The audio output device (300) may confirm that the preset signal (150) is added by passing the modified LFE channel audio signal through the band pass filter (312).

[0112] In one embodiment, the audio output device (300) can determine whether the LFE channel audio signal filtered by the band pass filter (312) exceeds a threshold. The audio output device (300) can obtain a frequency-intensity graph of the LFE channel audio signal filtered by the band pass filter (312). It can be determined whether an intensity exceeding the threshold is detected in a predetermined frequency range within the obtained graph. If an intensity exceeding the threshold is detected in a predetermined frequency range, the audio output device (300) can determine that a preset signal (150) is added to the LFE channel audio signal (141).

[0113] The audio output device (300) can determine that a case in which a preset signal (150) is added to an LFE channel audio signal is a case in which sound reproduction through a height channel is required. The audio output device (300) can output sound according to a 7-channel audio signal (142) through a 5.0.2 channel output port (322). The 7-channel audio signal (142) can be output through a 5.0.2 channel layout. The 5.0.2 channel layout can be a channel layout having two height channels.

[0114] The unmodified LFE channel audio signal may be an audio signal to which the preset signal (150) is not added. The LFE channel audio signal (141) may be blocked by the band pass filter (312). The audio output device (300) can confirm that the preset signal (150) is not added by passing the unmodified LFE channel audio signal through the band pass filter (312).

[0115] The audio output device (300) can determine that a case in which a preset signal (150) is not added to an LFE channel audio signal is a case in which sound reproduction through a height channel is not required. The audio output device (300) can output sound according to a 7-channel audio signal (142) through a 7.0.0 channel output port (323). The 7-channel audio signal (142) can be output through a 7.0.0 channel layout. The 7.0.0 channel layout may be a channel layout that does not have a height channel.

[0116] In FIG. 1, since an 8-channel audio signal was used as an example, it was described that a 7-channel audio signal (142) is output in a 5.0.2 channel layout or a 7.0.0 channel layout. However, the present disclosure is not limited thereto, and a method according to an embodiment of the present disclosure may be utilized to distinguish between a 5.1.0 channel layout and a 3.1.2 channel layout, and may be utilized to distinguish between a 9.1.0 channel layout, a 7.1.2 channel layout, and a 5.1.4 channel layout. The present disclosure is not limited to the above examples.

[0117] In one embodiment, an audio processing device (100) configured to process a multi-channel audio signal and an audio output device (300) configured to output a multi-channel audio signal are described separately, but some or all of the operations performed by each device may be performed by the audio processing device (100) or may be performed by the audio output device (300).

[0118] FIG. 2 is a flowchart illustrating an audio processing method for classifying a multi-channel audio signal according to an embodiment of the present disclosure.

[0119] Referring to FIG. 2, in step S210, the electronic device can obtain playback layout information related to sound playback using multiple channels.

[0120] In one embodiment, the electronic device can obtain bitstream and playback layout information. For example, the electronic device can obtain audio bitstream and playback layout information from a server providing a streaming service (e.g., an over-the-top (OTT) service).

[0121] A bitstream may contain a compressed audio signal for sound played using multiple channels. An electronic device can receive the bitstream as input and reconstruct the sound played using multiple channels. The electronic device can obtain a multi-channel audio signal from the bitstream.

[0122] The playback layout information may include information regarding the channel layout for reproducing sound according to the acquired bitstream. For example, an electronic device may acquire a playable multi-channel audio signal through an 8-channel layout from the bitstream, and the playback layout information may include information specifying that the multi-channel audio signal acquired in a 5.1.2 channel layout among the 8-channel layouts be played.

[0123] In step S220, the electronic device can obtain a first audio signal regarding audio played through an LFE channel among a plurality of channels.

[0124] In one embodiment, an electronic device may obtain a multi-channel audio signal from a bitstream. The multi-channel audio signal may include a plurality of audio signals playable through a plurality of channels. The electronic device may obtain a first audio signal relating to sound played through an LFE channel.

[0125] The first audio signal may include an audio signal playable through an LFE channel that outputs low-frequency sound effects.

[0126] In step S230, the electronic device can determine whether to acquire a second audio signal based on the playback layout information.

[0127] In one embodiment, the electronic device can determine whether to modify the first audio signal based on the playback layout information. The electronic device can determine the channel layout in which the first audio signal will be played based on the playback layout information. The electronic device can determine whether to acquire the second audio signal based on the determined channel layout.

[0128] For example, if the electronic device determines that sound should be reproduced with a channel layout including a height channel based on the playback layout information, the electronic device may acquire a second audio signal. If the electronic device determines that sound should not be reproduced with a channel layout including a height channel based on the playback layout information, the electronic device may maintain the first audio signal.

[0129] In one embodiment, the second acoustic signal may be a signal modified from the first acoustic signal. The second acoustic signal may be a different signal from the first acoustic signal. If the electronic device determines that it will acquire the second acoustic signal, it may acquire the second acoustic signal by modifying the first acoustic signal.

[0130] For example, an electronic device can obtain a second audio signal by adding a preset signal to a first audio signal. As another example, an electronic device can obtain a second audio signal by modulating a carrier signal to the first audio signal. However, the method of modifying a first audio signal to obtain a second audio signal is merely an example, and the present disclosure is not limited thereto.

[0131] In step S240, the electronic device can transmit the first acoustic signal or the second acoustic signal to the external device based on the determination result in step S230.

[0132] In one embodiment, the electronic device may maintain the first acoustic signal or acquire the second acoustic signal based on the determination result. The electronic device may transmit the first acoustic signal or the second acoustic signal to an external device based on the determination result.

[0133] For example, if the electronic device determines that sound should be reproduced with a channel layout including a height channel based on the playback layout information, the electronic device may transmit a second audio signal to the external device. If the electronic device determines that sound should not be reproduced with a channel layout including a height channel based on the playback layout information, the electronic device may transmit a first audio signal to the external device.

[0134] In one embodiment, the electronic device may transmit the first audio signal or the second audio signal to an external device via a communication device. For example, the electronic device may transmit the first audio signal or the second audio signal to an audio output device via HDMI.

[0135] FIG. 3 is a flowchart illustrating a method for determining whether to modify an acoustic signal depending on whether there is a height channel according to an embodiment of the present disclosure.

[0136] For convenience of explanation, parts that overlap with those described using Figures 1 and 2 are simplified or omitted.

[0137] Referring to FIG. 3, step S230 of FIG. 2 may include steps S310 and S320.

[0138] In step S310, the electronic device can obtain whether a height channel is required among multiple channels based on the playback layout information. For example, the electronic device can obtain a multi-channel audio signal playable through an 8-channel layout from the bitstream, and the playback layout information can include information specifying that the multi-channel audio signal is to be played in a 5.1.2 channel layout among the 8-channel layouts.

[0139] In step S320, the electronic device may determine whether to acquire a second acoustic signal based on whether a height channel is required.

[0140] In one embodiment, the electronic device may determine, based on the playback layout information, whether a multi-channel audio signal corresponding to a bitstream is required to be played back according to a channel layout including a height channel.

[0141] An electronic device may be capable of modifying a first audio signal when a multi-channel audio signal is required to be reproduced according to a channel layout including a height channel. The electronic device may obtain a modified second audio signal from the first audio signal.

[0142] The electronic device may not modify the first acoustic signal if the multichannel audio signal is required to be reproduced according to a channel layout that does not include a height channel.

[0143] After step S320 is performed, step S240 may be performed. If the electronic device obtains a second acoustic signal by modifying the first acoustic signal, the electronic device may transmit the second acoustic signal to the external device. If the electronic device does not modify the first acoustic signal, the electronic device may transmit the first acoustic signal to the external device.

[0144] FIG. 4 is a flowchart illustrating a method for determining an acoustic signal to be transmitted to an external device according to one embodiment of the present disclosure.

[0145] For convenience of explanation, parts that overlap with those described using Figures 2 and 3 are simplified or omitted.

[0146] Referring to FIG. 4, step S240 of FIG. 2 may include steps S410 to S430.

[0147] In step S410, the electronic device can determine whether a height channel is required based on the playback layout information.

[0148] In one embodiment, the playback layout information may include information regarding a channel layout for playing a multi-channel audio signal corresponding to the bitstream. For example, the playback layout information may include information specifying that the multi-channel audio signal is to be played according to a 5.1.2 channel layout.

[0149] An electronic device can determine whether a channel layout for reproducing a multi-channel audio signal corresponding to a bit stream includes a height channel based on playback layout information. The electronic device can determine whether a specific channel layout requires a height channel based on the playback layout information.

[0150] In step S420, the electronic device may transmit a second acoustic signal to an external device if a height channel is required.

[0151] In one embodiment, the electronic device can modify a first acoustic signal when a height channel is required. The electronic device can obtain a second acoustic signal by modifying the first acoustic signal. The electronic device can transmit the second acoustic signal to an external device. For example, the electronic device can transmit the second acoustic signal to an audio output device.

[0152] The method for modifying the first acoustic signal is not limited to the present disclosure. For example, the first acoustic signal may be modified by adding a preset signal, or by performing a modulation operation based on a carrier signal.

[0153] In step S430, the electronic device may transmit a first acoustic signal to an external device if a height channel is not required.

[0154] In one embodiment, the electronic device may not modify the first acoustic signal if a height channel is not required. The electronic device may transmit the first acoustic signal to an external device. For example, the electronic device may transmit the first acoustic signal to an audio output device.

[0155] FIG. 5A is a conceptual diagram illustrating an example of a method for classifying a multi-channel audio signal according to an embodiment of the present disclosure, in which signals are transmitted between each component.

[0156] For convenience of explanation, parts that overlap with those described using Figures 1 to 4 are simplified or omitted.

[0157] Referring to FIG. 5A, a system according to one embodiment can obtain an audio bitstream (e.g., 5.1.2 channels). The audio bitstream can be an audio signal transmitted by encoding an audio signal.

[0158] In one embodiment, the audio processing device (510a) may obtain an audio bitstream from an external device. For example, the audio processing device (510a) may obtain an audio bitstream from a server providing a streaming service (e.g., an over-the-top (OTT) service).

[0159] An audio bitstream may be an audio signal that is required to be played back according to a specific channel layout. For example, the audio bitstream may be acquired together with playback layout information (130 in FIG. 1), and the playback layout information may include information about the channel layout for playing back the audio bitstream.

[0160] Examples of channel layouts for playing back audio bitstreams include, but are not limited to, a 6-channel layout (e.g., a 3.1.2 channel layout and a 5.1.0 channel layout), an 8-channel layout (e.g., a 5.1.2 channel layout and a 7.1.0 channel layout), and a 10-channel layout (e.g., a 5.1.4. channel layout, a 7.1.2 channel layout, and a 9.1.0 channel layout), and various other channel layouts are possible.

[0161] Figure 5a illustrates an example of an audio bitstream (5.1.2 channels) played back in a 5.1.2 channel layout.

[0162] In one embodiment, the audio processing device (510a) can obtain a multi-channel audio signal (e.g., 8 channels) by inputting an audio bitstream (5.1.2 channels). The audio processing device (510a) can restore a multi-channel audio signal by using compressed audio signals of independent channels received from the audio bitstream (5.1.2 channels).

[0163] In one embodiment, the audio processing device (510a) can transform a restored audio signal to obtain a multi-channel audio signal (8 channels). The audio processing device (510a) can determine whether to transform the restored audio signal based on information about a channel layout for reproducing an audio bitstream (5.1.2 channels).

[0164] For example, the audio processing unit (510a) can determine whether a height channel is required based on information about the channel layout for reproducing an audio bitstream (5.1.2 channels). As illustrated in FIG. 5a, a height channel is required when the audio bitstream (5.1.2 channels) is reproduced according to a 5.1.2 channel layout.

[0165] In one embodiment, the audio processing device (510a) may transform the restored audio signal when a height channel is required in the channel layout for reproducing an audio bitstream (5.1.2 channels). By transforming the restored audio signal, the audio processing device (510a) may obtain a multi-channel audio signal (8 channels).

[0166] For example, the audio processing device (510a) may add a preset signal to the restored audio signal. The restored audio signal may be an audio signal of multiple channels, and the audio processing device (510a) may add the preset signal to the audio signal of the LFE channel among the restored audio signals. The preset signal may include a signal having a high frequency, and may be a signal having a frequency range that is distinct from the audio signal of the LFE channel that outputs low-frequency sound effects.

[0167] As another example, the audio processing device (510a) may perform a modulation operation on the restored audio signal using a carrier signal. The restored audio signal may be a multi-channel audio signal, and the audio processing device (510a) may perform a modulation operation on the audio signal of the LFE channel among the restored audio signals using the carrier signal. For example, the modulation operation may include an operation of multiplying the audio signal by the carrier signal, and the frequency of the audio signal may be modified through the modulation operation.

[0168] In one embodiment, the audio output device (520a) can obtain a multi-channel audio signal (8 channels). The multi-channel audio signal (8 channels) can include information indicating that the audio signal has been modified by adding a preset signal or performing a modulation operation. The multi-channel audio signal (8 channels) can include information indicating that a height channel is required in the channel layout for playing back an audio bitstream by adding a preset signal or performing a modulation operation.

[0169] In one embodiment, the audio output device (520a) can obtain information that a height channel is required for a channel layout for playing an audio bitstream (5.1.2 channels) by analyzing a multi-channel audio signal (8 channels). The audio output device (520a) can output audio (5.1.2 channels) according to a channel layout including a height channel based on the multi-channel audio signal (8 channels).

[0170] FIG. 5b is a conceptual diagram illustrating an example of a method for classifying a multi-channel audio signal according to an embodiment of the present disclosure, in which signals are transmitted between each component.

[0171] For convenience of explanation, the following description focuses on differences from those described using FIGS. 1 to 5a. For reference, FIG. 5b illustrates an example in which an audio bitstream (7.1.0 channel) reproduced in a 7.1.0 channel layout is acquired.

[0172] Referring to FIG. 5b, a system according to an embodiment can obtain an audio bitstream (7.1.0 channels). The audio bitstream can be an audio signal transmitted by encoding an audio signal.

[0173] In one embodiment, the audio processing device (510b) can obtain a multi-channel audio signal (8 channels) by inputting an audio bitstream (7.1.0 channels). The audio processing device (510b) can restore a multi-channel audio signal by using compressed audio signals of independent channels received from the audio bitstream (7.1.0 channels).

[0174] In one embodiment, the audio processing device (510b) can transform a restored audio signal to obtain a multi-channel audio signal (8 channels). The audio processing device (510b) can determine whether to transform the restored audio signal based on information about a channel layout for reproducing an audio bitstream (7.1.0 channels).

[0175] For example, the audio processing unit (510b) can determine whether a height channel is required based on information about the channel layout for playing back an audio bitstream (7.1.0 channel). As illustrated in FIG. 5b, if the audio bitstream (7.1.0 channel) is played back according to the 7.1.0 channel layout, a height channel is not required.

[0176] In one embodiment, the audio processing device (510b) may transmit the restored audio signal as a multi-channel audio signal (8 channels) to the audio output device (520b) when a height channel is not required in the channel layout for reproducing the audio bitstream (7.1.0 channels). When a height channel is not required, the audio processing device (510b) may use the audio signal restored from the audio bitstream (10) as a multi-channel audio signal (8 channels) without modification.

[0177] In one embodiment, the audio output device (520b) can obtain a multi-channel audio signal (8 channels). The multi-channel audio signal (8 channels) can be an unmodified signal, and the unmodified multi-channel audio signal (8 channels) can include information indicating that a height channel is not required in the channel layout for playing the audio bitstream (7.1.0 channels).

[0178] In one embodiment, the audio output device (520b) can obtain information that a height channel is not required for a channel layout for playing an audio bitstream (7.1.0 channels) by analyzing a multi-channel audio signal (8 channels). The audio output device (520b) can output audio (7.1.0 channels) according to a channel layout that does not include a height channel, based on the multi-channel audio signal (8 channels).

[0179] Conventional audio output devices acquire multi-channel audio signals, but, for example, only receive 8-channel audio signals and do not acquire information about the channel layout in which the 8 channels are configured. Referring to FIGS. 5A and 5B , a system according to an embodiment of the present disclosure transmits a multi-channel audio signal (8 channels) containing information about whether height channels are required to an audio output device by modifying the audio signal. Accordingly, the audio output device can determine whether height channels are required and, accordingly, determine an appropriate channel layout to output sound (5.1.2 channels or 7.1.0 channels).

[0180] FIG. 6A is a graph illustrating a first acoustic signal related to sound reproduced through an LFE (Low Frequency Effect) channel according to an embodiment of the present disclosure. FIG. 6B is a graph illustrating a second acoustic signal modified from the first acoustic signal according to an embodiment of the present disclosure.

[0181] For reference, FIGS. 6A and 6B are frequency-time graphs of an LFE channel audio signal among multi-channel audio signals transmitted from an audio processing device to an audio output device according to one embodiment. Specifically, FIG. 6A is a graph for an unmodified LFE channel audio signal, and FIG. 6B is a graph for an LFE channel audio signal modified by adding a preset signal.

[0182] Referring to FIG. 6A, a graph for an unmodified LFE channel audio signal (60a) is illustrated. The LFE channel audio signal (60a) is an audio signal that can be reproduced through a channel for outputting low-frequency sound effects. The LFE channel audio signal (60a) can be generated in a low-frequency range. The LFE channel audio signal (60a) can include an audio signal having a low-band frequency. For example, the LFE channel audio signal (60a) can include an audio signal having a frequency band below 400 Hz.

[0183] Referring to FIG. 6b, a graph for an LFE channel audio signal (60b) modified by adding a preset signal is illustrated. The modified LFE channel audio signal (60b) may include an original LFE channel audio signal (61b) and a preset signal (62b). The modified LFE channel audio signal (60b) may be a combination of the original LFE channel audio signal (61b) and the preset signal (62b).

[0184] In one embodiment, the original LFE channel audio signal (61b) may mean the LFE channel audio signal before the preset signal (62b) is added, and may be identical to the unmodified LFE channel audio signal (60a) of FIG. 6a.

[0185] In one embodiment, the preset signal (62b) may be a signal having a frequency range that is distinct from the LFE channel audio signal (61b). The preset signal (62b) may be a signal having a high frequency range that is distinct from the low frequency range of the LFE channel. For example, the frequency range of the preset signal (62b) may not overlap with the frequency range of the LFE channel.

[0186] In one embodiment, if it is determined that a height channel is required to reproduce sound including an LFE channel audio signal, the electronic device may transmit a modified LFE channel audio signal (60b) with an added preset signal (62b) to an external device. If it is determined that a height channel is not required to reproduce sound including an LFE channel audio signal, the electronic device may transmit an unmodified LFE channel audio signal (60a) of FIG. 6A to the external device.

[0187] In further detail with reference to FIGS. 6A and 6B, in one embodiment, when the LFE channel audio signal (141) is modified according to the determination in step S10, the audio output device (300) can receive the LFE channel audio signal to which the preset signal (150) is added. The received LFE channel audio signal is, for example, the modified LFE channel audio signal (60b) illustrated by the graph of FIG. 6B.

[0188] The audio output device (300) can apply the modified LFE channel audio signal (60b) to a low pass filter (311). By filtering the modified LFE channel audio signal (60b) using the low pass filter (311), the audio output device (300) can obtain only the original LFE channel audio signal (61b) having a low frequency range. The audio output device (300) can output the original LFE channel audio signal (61b) through the LFE output port (321).

[0189] The audio output device (300) can apply the modified LFE channel audio signal (60b) to the band pass filter (312). As the audio output device (300) filters the modified LFE channel audio signal (60b) using the band pass filter (312), the audio output device (300) can determine whether a preset signal (e.g., 150, 62b) having a predetermined frequency range has been added. Referring to the graph of FIG. 6b, since the preset signal (62b) having a predetermined frequency range is included in the modified LFE channel audio signal (60b), the audio output device (300) can confirm that the preset signal (62b) has been added. When the preset signal (62b) has been added, the audio output device (300) can output a 7-channel audio signal (142) through the 5.0.2 channel output port (322). That is, the audio output device (300) determines that sound should be reproduced in a 5.0.2 channel layout including a height channel, and can output a 7-channel audio signal (142) in a 5.0.2 channel layout.

[0190] In one embodiment, if the LFE channel audio signal (141) is not modified based on the determination in step S10, the audio output device (300) can receive the unmodified LFE channel audio signal. The received LFE channel audio signal is, for example, the unmodified LFE channel audio signal (60a) illustrated by the graph of FIG. 6a.

[0191] The audio output device (300) can apply the unmodified LFE channel audio signal (60a) to a low pass filter (311). Since the unmodified LFE channel audio signal (60a) only includes signals having a low frequency range, the audio output device (300) can obtain the unmodified LFE channel audio signal (60a) as is. The audio output device (300) can output the unmodified LFE channel audio signal (60a) through the LFE output port (321).

[0192] The audio output device (300) can apply the unmodified LFE channel audio signal (60a) to the band pass filter (312). As the audio output device (300) filters the unmodified LFE channel audio signal (60a) using the band pass filter (312), it can determine whether a preset signal (150) having a predetermined frequency range is added. Referring to the graph of FIG. 6A, since the unmodified LFE channel audio signal (60a) includes only signals in the low frequency range, the audio output device (300) can confirm that the preset signal (150) is not added. When the preset signal (150) is not added, the audio output device (300) can output a 7-channel audio signal (142) through the 7.0.0 channel output port (323). That is, the audio output device (300) determines that sound should be played in a 7.0.0 channel layout that does not include a height channel, and can output sound through the 7.0.0 channel layout.

[0193] FIG. 7 is a conceptual diagram illustrating a method for reproducing sound when an audio system is not equipped with a height channel, according to one embodiment of the present disclosure.

[0194] For convenience of explanation, parts that overlap with those described using Figures 1 to 6 are simplified or omitted.

[0195] Referring to FIG. 7, an audio processing device (710) can obtain a multi-channel audio signal (8 channels) by inputting an audio bitstream (7.1.0 channels). The multi-channel audio signal (8 channels) may be a signal corresponding to a 5.1.2 channel layout including five surround channels (L, R, C, SL, SR), one LFE channel, and two height channels (HFL, HFR).

[0196] In one embodiment, the audio output device (720) can obtain a multi-channel audio signal (8 channels). The multi-channel audio signal (8 channels) can be modified by adding a preset signal or performing a modulation operation. The audio signal can be modified by adding a preset signal to an LFE channel audio signal among the multi-channel audio signals (8 channels). The modification of the multi-channel audio signal (8 channels) can correspond to information indicating that a height channel is required in the channel layout for playing back an audio bitstream.

[0197] In one embodiment, the audio output device (720) can obtain information that a height channel is required for a channel layout for playing an audio bitstream (5.1.2 channels) by analyzing a multi-channel audio signal (8 channels).

[0198] In one embodiment, the audio output device (720) may not have a height channel. Even if the audio output device (720) obtains information that a height channel is required, the audio output device (720) may not be able to reproduce sound with a channel layout that includes a height channel. The audio output device (720) may distribute sound so that an audio bitstream (5.1.2 channels) can be reproduced through a channel layout that excludes the height channel.

[0199] In one embodiment, the audio output device (720) can output sound according to a multi-channel audio signal (8 channels) including a height channel through 6 channels.

[0200] For example, the audio output device (720) can obtain a multi-channel audio signal (8 channels). The audio output device (720) can output sound according to 6-channel audio signals (L, R, C, LFE, SL, SR) excluding height channels (HFL, HFR) through a 5.1.0 channel output port. The audio output device (720) may not output sound according to audio signals reproduced through height channels (HFL, HFR).

[0201] As another example, the audio output device (720) can obtain a multi-channel audio signal (8 channels). The audio output device (720) can mix audio signals played through height channels (HFL, HFR). The audio output device (720) can convert the 8-channel audio signal into a 6-channel (5.1.0 channel) audio signal by mixing it. The audio output device (720) can output the mixed 6-channel audio signal through a 5.1.0 channel output port.

[0202] In one embodiment, the audio output device (720) can output sound according to a multi-channel audio signal (8 channels) including a height channel through 8 channels not including a height channel. The audio output device (720) can output sound according to a multi-channel audio signal played back in a 5.1.2 channel layout through a 7.1.0 channel layout.

[0203] For example, the audio output device (720) can obtain a multi-channel audio signal (8 channels). The audio output device (720) can mix audio signals played back through height channels (HFL, HFR). The audio output device (720) can convert the 8-channel audio signal into an 8-channel (7.1.0 channel) audio signal by mixing the 8-channel audio signal. The audio output device (720) can output the mixed 8-channel audio signal through a 7.1.0 channel output port.

[0204] FIG. 8 is a conceptual diagram illustrating a system for classifying a multi-channel audio signal according to an embodiment of the present disclosure.

[0205] For convenience of explanation, the explanation will focus on parts that are different from those described using Figure 1.

[0206] Referring to FIG. 8, the audio processing system (2000) may include an audio processing device (400), a communication module (500), and an audio output device (600).

[0207] The audio processing device (400) can process multi-channel audio signals. The audio processing device (400) can acquire multi-channel audio signals and transform audio signals of some channels of the multi-channel audio signals. The audio processing device (400) can transmit the transformed audio signals to the audio output device (600) via the communication module (500).

[0208] 1. Operation of audio processing device (400)

[0209] In one embodiment, the audio processing device (400) can modify the LFE channel audio signal (441) based on the playback layout information (430). The audio processing device (400) can perform a modulation operation on the LFE channel audio signal (441) using the carrier signal (450). The audio processing device (400) can determine whether to modify the LFE channel audio signal (441) based on the playback layout information (430).

[0210] In step S30, the audio processing device (400) can obtain whether a height channel is required for sound reproduction according to the sound bitstream (10) based on the reproduction layout information (430). If a height channel is required, the audio processing device (400) can perform a modulation operation based on a carrier signal (450) on an LFE channel audio signal (441). If a height channel is not required, the audio processing device (400) may not perform a modulation operation based on a carrier signal (450) on an LFE channel audio signal (441).

[0211] The audio processing device (400) can transmit an unmodified LFE channel audio signal or a modified LFE channel audio signal to the audio output device (600) through the communication module (500) according to the playback layout information (430). The audio output device (600) can determine whether a height channel is required for sound reproduction according to the audio bitstream (10) based on the received audio signal. The audio output device (600) can reproduce sound through an appropriate channel layout based on whether a height channel is required.

[0212] In the present disclosure, the first audio signal may refer to a signal regarding audio reproduced through an LFE channel. The first audio signal may refer to an unmodified LFE channel audio signal (141, 441), and may refer to an LFE channel audio signal (441) before or after the modulation operation of FIG. 8 is performed.

[0213] In the present disclosure, the second audio signal refers to an LFE channel audio signal modified from the first audio signal. The signal modification method may vary, such as addition or modulation, and is not limited to the present disclosure. The second audio signal may be different from the first audio signal. The second audio signal may refer to an LFE channel audio signal modified by performing the modulation operation of FIG. 8.

[0214] 2. Operation of audio output device (600)

[0215] The audio output device (600) can process a modified multi-channel audio signal and output the processed multi-channel audio signal. The audio output device (600) can obtain a multi-channel audio signal modified by the audio processing device (400) or an unmodified multi-channel audio signal through the communication module (500). The audio output device (600) can determine whether a height channel is required from the unmodified multi-channel audio signal or the modified multi-channel audio signal, and can output sound based on the required channel layout.

[0216] In one embodiment, the audio output device (600) may include a low-pass filter (611) and a band-pass filter (612).

[0217] 2.1. Application of low-pass filter (611) in audio output device (600)

[0218] In one embodiment, the audio output device (600) can filter the LFE channel audio signal modified by the audio processing device (400) or the LFE channel audio signal not modified by the audio processing device (400) through a low pass filter (611).

[0219] In step S40, the audio output device can determine whether the LFE channel audio signal is modified based on the LFE channel audio signal filtered by the low pass filter (611). The audio output device (600) can determine whether a modulation operation has been performed based on the LFE channel audio signal filtered by the low pass filter (611).

[0220] The LFE channel audio signal includes signals in the low frequency range and can be passed by the low pass filter (611). The LFE channel audio signal, for which a modulation operation is performed based on the carrier signal (450), includes signals in the relatively high frequency range and can be blocked by the low pass filter (611).

[0221] 2.1.1. If the LFE channel audio signal is not distorted

[0222] In one embodiment, when there is an LFE channel audio signal passed by the low pass filter (611), it means that a modulation operation is not performed on the LFE channel audio signal, and the LFE channel audio signal on which the modulation operation is not performed can be output through the LFE channel output port. The audio output device (600) can output sound according to the unmodified LFE channel audio signal through the LFE output port (621).

[0223] In one embodiment, the presence of an LFE channel audio signal passed by the low pass filter (611) may correspond to a case in which no modulation operation is performed on the LFE channel audio signal, while at the same time, the absence of an LFE channel audio signal passed by the band pass filter (612) may correspond to a case in which no modulation operation is performed on the LFE channel audio signal. That is, the LFE channel audio signal has a relatively high frequency range as the modulation operation is performed, and may be blocked by the low pass filter (611) and passed by the band pass filter (612).

[0224] In step S60, based on the determination as to whether there is an LFE channel audio signal that has passed through the band pass filter (612), if there is no LFE channel audio signal that has passed through the band pass filter (612), the 7-channel audio signal (442) can be output through the 7.0.0 channel output port. The audio output device (600) can output sound according to the 7-channel audio signal through the 7.0.0 channel output port (623). Consequently, in step S30, if it is determined that sound reproduction in a 5.1.2 channel layout is not required, the audio output device (600) can output the LFE channel sound output through the LFE output port (621) and the 7.0.0 channel sound output through the 7.0.0 channel output port (623). The audio output device (600) can output sound according to the 7.1.0 channel layout.

[0225] 2.1.2. If the LFE channel audio signal is distorted

[0226] In step S40, in one embodiment, if there is no LFE channel audio signal passed by the low pass filter (611), it may mean that a modulation operation has been performed on the LFE channel audio signal. In this case, according to step S50, the audio output device (600) may determine whether there is an LFE channel audio signal filtered by the band pass filter (612). The LFE channel audio signal on which the modulation operation has been performed may be passed by the band pass filter (612). The audio output device (600) may perform a de-modulation operation on the LFE channel audio signal passed by the band pass filter (612) based on the carrier signal (650).

[0227] The carrier signal (650) used by the audio output device (600) for demodulation may be the same as the carrier signal (450) used by the audio processing device (400) for demodulation. This is merely an example of performing an inverse operation and does not limit the present disclosure.

[0228] The audio output device (600) can output sound according to the LFE channel audio signal on which the demodulation operation has been performed through the LFE output port (621).

[0229] In addition, if there is an LFE channel audio signal passed by the band pass filter (612) according to the judgment in step S60, the 7-channel audio signal (442) can be output through the 5.0.2 channel output port. The audio output device (600) can output sound according to the 7-channel audio signal through the 5.0.2 channel output port (622). Consequently, if it is determined in step S30 that sound is required to be reproduced in a 5.1.2 channel layout, the audio output device (600) can output the LFE channel sound output through the LFE output port (621) and the 5.0.2 channel sound output through the 5.0.2 channel output port (622). The audio output device (600) can output sound according to the 5.1.2 channel layout.

[0230] In one embodiment, an audio processing device (400) configured to process a multi-channel audio signal and an audio output device (600) configured to output a multi-channel audio signal are described separately, but some or all of the operations performed by each device may be performed by the audio processing device (400) or may be performed by the audio output device (600).

[0231] FIG. 9 is a flowchart illustrating a method for classifying a multi-channel audio signal according to an embodiment of the present disclosure.

[0232] For convenience of explanation, parts that overlap with those described using Figure 2 are simplified or omitted.

[0233] Referring to FIG. 9, in step S910, the electronic device can determine a channel layout for reproducing sound by filtering the first sound signal or the second sound signal.

[0234] In one embodiment, the electronic device may filter a first audio signal or a second audio signal. The first audio signal may be an unmodified LFE channel audio signal, and the second audio signal may be a modified LFE channel audio signal. The first audio signal may include a signal in a low frequency range. The second audio signal may be a signal in which a preset signal in a relatively high frequency range is added to the first audio signal. As another example, the second audio signal may be a signal in which a modulation operation is performed on the first audio signal.

[0235] An electronic device may filter a first audio signal or a second audio signal using a band-pass filter. The first audio signal may be blocked by the band-pass filter. The second audio signal may be partially blocked by the band-pass filter and partially passed through. A preset signal added to the second audio signal may be passed through the band-pass filter. As another example, a portion of the second audio signal on which a modulation operation has been performed may be passed through the band-pass filter.

[0236] Based on the result of filtering the first acoustic signal or the second acoustic signal using a band-pass filter, it can be determined whether the first acoustic signal or the second acoustic signal has been filtered. By filtering the first acoustic signal or the second acoustic signal using a band-pass filter, it can be determined whether the first acoustic signal has been modified. By filtering the first acoustic signal or the second acoustic signal using a band-pass filter, it can be determined whether sound is required to be output with a channel layout including a height channel.

[0237] In one embodiment, the electronic device may be implemented as a device capable of audio output, such as a sound bar, TV, mobile phone, tablet PC, or laptop. The electronic device may be an audio output device.

[0238] FIG. 10 is a flowchart illustrating a method for classifying a multi-channel audio signal according to an embodiment of the present disclosure.

[0239] For convenience of explanation, parts that overlap with those described using FIG. 2 and FIG. 9 are simplified or omitted.

[0240] In one embodiment, step S910 of FIG. 9 may include steps S1010 and S1020.

[0241] In step S1010, the electronic device can determine whether a preset signal has been added by applying the first acoustic signal or the second acoustic signal to a band pass filter.

[0242] In one embodiment, a first audio signal may be blocked by a band-pass filter. A second audio signal may be partially blocked by the band-pass filter and partially passed through. A preset signal added to the second audio signal may be passed through the band-pass filter.

[0243] If a signal passing through the band-pass filter is detected by applying the first or second acoustic signal, it can be determined that a preset signal has been added. If a signal passing through the band-pass filter is not detected by applying the first or second acoustic signal, it can be determined that a preset signal has not been added.

[0244] Accordingly, the electronic device can determine whether a preset signal has been added by applying the first acoustic signal or the second acoustic signal to a band pass filter.

[0245] In step S1020, the electronic device can determine the channel layout based on whether a preset signal is added.

[0246] In one embodiment, when a preset signal is added to a first audio signal to generate a second audio signal, the audio needs to be output through a channel layout including a height channel. In this case, the electronic device can determine a channel layout including a height channel among various channel layouts.

[0247] For example, an electronic device may output sound through a 5.1.2 channel layout that includes a height channel in an 8-channel layout.

[0248] In one embodiment, when a preset signal is not added to the first audio signal, the audio needs to be output through a channel layout that does not include a height channel. In this case, the electronic device can determine a channel layout that does not include a height channel among various channel layouts.

[0249] For example, an electronic device may output sound through a 7.1.0 channel layout that does not include height channels in an 8-channel layout.

[0250] In one embodiment, the electronic device may be implemented as a device capable of audio output, such as a sound bar, TV, mobile phone, tablet PC, or laptop. The electronic device may be an audio output device.

[0251] FIG. 11 is a flowchart illustrating a method for reproducing sound through an appropriate channel layout based on a multi-channel audio signal, according to one embodiment of the present disclosure.

[0252] For convenience of explanation, parts that overlap with those described using Fig. 9 are simplified or omitted.

[0253] In step S1110, the electronic device can apply the first acoustic signal or the second acoustic signal to a low pass filter to generate an output signal.

[0254] In one embodiment, the first audio signal may be an LFE channel audio signal, and the second audio signal may be a signal to which a preset signal is added to the LFE channel audio signal. The preset signal may be blocked by a low-pass filter. By applying the first audio signal or the second audio signal to the low-pass filter, the LFE channel audio signal may be consistently obtained. The electronic device may apply the first audio signal or the second audio signal to the low-pass filter to generate an output signal that can be reproduced by the LFE channel.

[0255] In step S1120, the electronic device can reproduce sound according to the output signal. The electronic device can reproduce sound according to the output signal through the LFE channel output port.

[0256] In one embodiment, the electronic device can reproduce sound based on audio signals of channels other than the LFE channel. For example, if an 8-channel layout including a height channel is required, the electronic device can reproduce sound based on a 7-channel audio signal through a 5.0.2 channel output port. In another example, if an 8-channel layout excluding a height channel is required, the electronic device can reproduce sound based on a 7-channel audio signal through a 7.0.0 channel output port.

[0257] In one embodiment, the electronic device may be implemented as a device capable of audio output, such as a sound bar, TV, mobile phone, tablet PC, or laptop. The electronic device may be an audio output device.

[0258] FIG. 12 is a conceptual diagram illustrating a system for classifying a multi-channel audio signal according to an embodiment of the present disclosure.

[0259] Anything that overlaps with what has been explained using Figures 1 and 8 is simplified or omitted.

[0260] Referring to FIG. 12, the audio processing system (3000) may include an audio processing device (700), a communication module (800), and an audio output device (900).

[0261] The audio processing device (700) can process multi-channel audio signals. The audio processing device (700) can acquire multi-channel audio signals and transform audio signals of some channels among the multi-channel audio signals. The audio processing device (700) can transmit the transformed audio signals to the audio output device (900) via the communication module (800).

[0262] 1. Operation of audio processing device (700)

[0263] The audio processing device (700) can modify the LFE channel audio signal (741) based on the playback layout information (730). The audio processing device (700) can perform an operation of adding one or more preset signals (750) to the LFE channel audio signal (741).

[0264] The audio processing device (700) can determine a combination of one or more preset signals (750) to be added to an LFE channel audio signal (741) based on the reproduction layout information (730). For example, the audio processing device (700) can add a first preset signal to the LFE channel audio signal (741) based on the reproduction layout information (730) that specifies to reproduce sound according to a first channel layout. The audio processing device (700) can transmit the LFE channel audio signal (741) to which the first preset signal is added to the audio output device (900).

[0265] As another example, the audio processing device (700) may add a first preset signal and a second preset signal to an LFE channel audio signal (741) based on reproduction layout information (730) that specifies to reproduce sound according to a second channel layout. The audio processing device (700) may transmit the LFE channel audio signal (741) to which a combination of the first preset signal and the second preset signal is added to the audio output device (900).

[0266] In one embodiment, a combination of one or more preset signals (750) added to an LFE channel audio signal (741) may correspond to a channel layout specified according to playback layout information (730).

[0267] In one embodiment, a combination of one or more preset signals (750) can represent binary information based on whether a preset signal is added. By adding a combination of one or more preset signals (750) to an LFE channel audio signal (741), the modified LFE channel audio signal (741) can include binary information.

[0268] For example, binary information corresponding to a combination of one or more preset signals (750) can be organized as shown in Table 2 below. However, the correspondence relationship described in Table 2 is merely an example and does not limit the present disclosure. A method of utilizing a combination of one or more preset signals (750) will be specifically described using Table 2.

[0269] Bit channel layout 000 Other signals 001 Mono channel layout (1.0.0) 010 Stereo channel layout (2.0.0) 0113.1.21005.1.01015.1.21107.1.0111-

[0270] Table 2 illustrates eight channel layouts corresponding to possible combinations with three preset signals as an example. However, the number of preset signals and the types of corresponding channel layouts do not limit the present disclosure, and a greater number of preset signals may be used to correspond to possible channel layouts. In one embodiment, the audio processing device (700) may add a combination of a first preset signal, a second preset signal, and a third preset signal to an LFE channel audio signal (741). Based on whether each preset signal is added to the LFE channel audio signal (741), 0 or 1 may be determined for each digit of a number expressed in binary. When a preset signal is added to the LFE channel audio signal (741), 1 may be determined for the corresponding digit of the number expressed in binary.

[0271] For example, the audio processing device (700) can add a first combination composed of a first preset signal and a second preset signal to the LFE channel audio signal (741). In this case, information expressed in binary may be '110'. Therefore, the audio processing device (700) can transmit information to reproduce sound in a 7.1.0 channel layout by adding a first combination composed of a first preset signal and a second preset signal to the LFE channel audio signal (741). The audio output device (900) can receive information to reproduce sound in a 7.1.0 channel layout from the LFE channel audio signal (741) to which the first combination composed of a first preset signal and a second preset signal is added.

[0272] As another example, the audio processing device (700) may add a second combination consisting of a first preset signal and a third preset signal to the LFE channel audio signal (741). In this case, the information expressed in binary may be '101'. Therefore, the audio processing device (700) may transmit information to reproduce sound in a 5.1.2 channel layout by adding a second combination consisting of the first preset signal and the third preset signal to the LFE channel audio signal (741). The audio output device (900) may receive information to reproduce sound in a 5.1.2 channel layout from the LFE channel audio signal (741) to which the second combination consisting of the first preset signal and the third preset signal is added.

[0273] In one embodiment, when a preset signal is not added to an LFE channel audio signal (741), information expressed in binary may be '000'. The channel layout corresponding to '000' may include other signals. An LFE channel audio signal (741) to which a preset signal is not added may be recognized as a other signal. LFE channel audio signals to which a preset signal is not added may be recognized as other signals by the audio processing device (700) of the present disclosure. For example, an LFE channel audio signal transmitted from an external audio device other than the audio processing device (700) may be recognized as a other signal.

[0274] In one embodiment, when a first preset signal, a second preset signal, and a third preset signal are added to an LFE channel audio signal (741), information expressed in binary may be '111'. In Table 2, a channel layout corresponding to '111' is not specified. Another channel layout may be specified corresponding to '111', or the corresponding channel layout may be empty. For example, when a new channel layout needs to be specified, '111' may correspond to the new channel layout, and the present disclosure is not limited thereto.

[0275] 2. Operation of audio output device (900)

[0276] The audio output device (900) can process a modified multi-channel audio signal and output the processed multi-channel audio signal. The audio output device (900) can obtain the multi-channel audio signal modified by the audio processing device (700) through the communication module (800). The audio output device (900) can identify a corresponding channel layout from the modified multi-channel audio signal and output sound based on the required channel layout.

[0277] In one embodiment, the audio output device (900) may include a low-pass filter (911) and one or more band-pass filters (912).

[0278] 2.1. Application of low-pass filter (911) in audio output device (900)

[0279] In one embodiment, the audio output device (900) can filter the LFE channel audio signal transformed by the audio processing device (700) through a low pass filter (911).

[0280] The modified LFE channel audio signal may be an audio signal to which a combination of one or more preset signals (750) is added. The preset signal (750) may be blocked by a low pass filter (911), and the audio output device (900) may restore the LFE channel audio signal (741) by applying the modified LFE channel audio signal to the low pass filter (911).

[0281] The audio output device (900) can restore the LFE channel audio signal (741) by applying the modified LFE channel audio signal to the low pass filter (911). If the LFE channel audio signal (741) is delivered to the audio output device (900) with one or more combinations of preset signals (750) added, the audio output device (900) can selectively remove the one or more combinations of preset signals (750) through the low pass filter (911).

[0282] The audio output device (900) can output sound according to an LFE channel audio signal (741) through an LFE output port (921). The LFE channel audio signal (741) can be output through an LFE channel. For example, the LFE channel audio signal (741) can be played through a subwoofer speaker.

[0283] 2.2. Application of a band pass filter (912) in an audio output device (900)

[0284] In one embodiment, the audio output device (900) can filter the LFE channel audio signal transformed by the audio processing device (700) through one or more band pass filters (912).

[0285] An audio output device (900) according to one embodiment can determine whether one or more preset signals (750) are added based on an LFE channel audio signal filtered by one or more band pass filters (912). The audio output device (900) can check a combination of one or more preset signals (750).

[0286] In one embodiment, the one or more band pass filters (912) may include a first band pass filter, a second band pass filter, and a third band pass filter. The first band pass filter may be a filter that passes a frequency range corresponding to the first preset signal. The second band pass filter may be a filter that passes a frequency range corresponding to the second preset signal. The third band pass filter may be a filter that passes a frequency range corresponding to the third preset signal. The audio output device (900) may use the first band pass filter, the second band pass filter, and the third band pass filter to obtain whether the modified LFE channel audio signal includes the first preset signal, the second preset signal, and the third preset signal, respectively.

[0287] In one embodiment, the audio output device (900) may filter an LFE channel audio signal through a first bandpass filter. If a signal is confirmed as a result of the filtering, the LFE channel audio signal may be determined to include a first preset signal. If a signal is not confirmed as a result of the filtering, the LFE channel audio signal may be determined not to include the first preset signal.

[0288] Similarly, the audio output device (900) can filter the LFE channel audio signal through a second band-pass filter. The audio output device (900) can filter the LFE channel audio signal through a third band-pass filter. The audio output device (900) can determine a combination of one or more preset signals added to the LFE channel audio signal based on a result of filtering the LFE channel audio signal through one or more band-pass filters (912).

[0289] In step S70, the audio output device (900) can determine the channel layout based on a combination of one or more preset signals added to the LFE channel audio signal.

[0290] In one embodiment, the audio output device (900) can obtain binary information based on a combination of one or more determined preset signals (750). The audio output device (900) can obtain a channel layout corresponding to the binary information.

[0291] For example, the audio output device (900) can identify a first combination composed of a first preset signal and a second preset signal by filtering the LFE channel audio signal (741) through one or more band pass filters (912). In this case, information expressed in binary may be '110'. Accordingly, the audio output device (900) can receive information to reproduce sound in a 7.1.0 channel layout from the first combination composed of the first preset signal and the second preset signal. The audio output device (900) can reproduce the LFE channel audio signal (741) through the LFE output port (921) and reproduce the other channel audio signal (742) through the 7.0.0 channel layout output port. For example, the first channel layout output port (922) may be a 7.0.0 channel layout output port.

[0292] As another example, the audio output device (900) can identify a second combination composed of a first preset signal and a third preset signal by filtering the LFE channel audio signal (741) through one or more band pass filters (912). In this case, the information expressed in binary may be '101'. Accordingly, the audio output device (900) can receive information to reproduce sound in a 5.1.2 channel layout from the second combination composed of the first preset signal and the third preset signal. The audio output device (900) can reproduce the LFE channel audio signal (741) through the LFE output port (921) and reproduce the other channel audio signals (742) through the 5.0.2 channel layout output port. For example, the Nth channel layout output port (923) may be a 5.0.2 channel layout output port.

[0293] In one embodiment, an audio processing device (700) configured to process a multi-channel audio signal and an audio output device (900) configured to output a multi-channel audio signal are described separately, but some or all of the operations performed by each device may be performed by the audio processing device (700) or may be performed by the audio output device (900).

[0294] FIG. 13 is a flowchart illustrating an audio processing method for classifying a multi-channel audio signal according to an embodiment of the present disclosure. For convenience of explanation, details that overlap with those described using FIG. 2 are simplified or omitted.

[0295] Referring to FIG. 13, in step S1310, the electronic device can obtain playback layout information related to sound playback using multiple channels. The description of step S1310 overlaps with that described using step S210 of FIG. 2 and is therefore omitted.

[0296] In step S1320, the electronic device can obtain a first audio signal regarding audio played through an LFE channel among multiple channels. The description of step S1320 is omitted as it overlaps with the description using step S220 of FIG. 2.

[0297] In step S1330, the electronic device can obtain a second acoustic signal different from the first acoustic signal by modifying the first acoustic signal based on the reproduction layout information.

[0298] In one embodiment, the electronic device can obtain a second audio signal by adding one or more preset signals to a first audio signal. Binary information can be added to the first audio signal based on whether one or more preset signals are added.

[0299] For example, an electronic device may determine whether to add a preset signal to a first audio signal. The electronic device may generate information of '1' or '0' depending on whether a preset signal is added to the first audio signal.

[0300] As another example, the electronic device may add one of two combinations of preset signals to the first audio signal. The electronic device may generate information of '11', '10', '01', or '00' depending on the combination of the two preset signals added to the first audio signal.

[0301] As another example, the electronic device may add one of three combinations of preset signals to the first audio signal. The electronic device may generate information of '111', '110', '101', '100', '011', '010', '001', or '000' depending on the combination of the three preset signals added to the first audio signal.

[0302] In one embodiment, the second acoustic signal may be an acoustic signal to which one or more preset signals are added to the first acoustic signal. The one or more added preset signals may be interpreted as binary information.

[0303] In one embodiment, each combination of one or more preset signals may correspond to a channel layout in which sound is to be reproduced. The binary information interpreted from the combination of one or more preset signals may correspond to the channel layout in which sound is to be reproduced. The electronic device may transmit information regarding the channel layout in which sound is to be reproduced based on the combination of one or more preset signals added to the first sound signal.

[0304] In step S1340, the electronic device can transmit a second acoustic signal to an external device. The description of step S1340 overlaps with that described using step S240 of FIG. 2, and is therefore simplified.

[0305] In one embodiment, the electronic device may transmit a second audio signal to an external device via a communication device. For example, the electronic device may transmit the second audio signal to an audio output device via HDMI.

[0306] FIG. 14 is a flowchart illustrating a method for classifying a multi-channel audio signal according to an embodiment of the present disclosure. For convenience of explanation, details that overlap with those described using FIG. 13 are simplified or omitted.

[0307] Referring to FIG. 14, step S1410 may be performed after step S1340 of FIG. 13.

[0308] In step S1410, the audio output device can obtain a combination of one or more preset signals by applying the second audio signal to one or more band pass filters.

[0309] In one embodiment, the audio output device can filter a second audio signal through one or more band-pass filters. The second audio signal can include a first audio signal (e.g., an LFE channel audio signal) and one or more preset signals. The first audio signal can be blocked through the band-pass filter, and the one or more preset signals can be passed through the one or more band-pass filters.

[0310] In one embodiment, the audio output device may include one or more band-pass filters corresponding to the frequency bands of each of the one or more preset signals. The audio output device may obtain whether each of the one or more preset signals is included by applying the one or more band-pass filters to the second audio signal.

[0311] For example, the audio output device can obtain whether the first preset signal is included by applying a first band-pass filter to the second audio signal. The audio output device can obtain whether the second preset signal is included by applying a second band-pass filter to the second audio signal. The audio output device can obtain whether the third preset signal is included by applying a third band-pass filter to the second audio signal. The number of band-pass filters may match the number of preset signals that can be added to the second audio signal, but the number of band-pass filters or the number of preset signals does not limit the present disclosure.

[0312] In one embodiment, the audio output device can obtain a combination of one or more preset signals based on whether one or more preset signals are included in the second audio signal.

[0313] In step S1320, the audio output device can determine a channel layout based on a combination of one or more preset signals.

[0314] In one embodiment, a combination of one or more preset signals may each correspond to a channel layout for reproducing sound. The combination of one or more preset signals may represent binary information.

[0315] For example, the audio processing device can generate a second audio signal based on a first preset signal, a second preset signal, and a third preset signal. The audio processing device can generate the second audio signal by adding a combination of the first preset signal, the second preset signal, and the third preset signal to the first audio signal. For example, a total of eight combinations are possible depending on whether the first preset signal, the second preset signal, and the third preset signal are included.

[0316] For example, the audio processing device can generate a second audio signal by adding a first combination consisting of a first preset signal and a second preset signal to the first audio signal. In this case, the information expressed in binary may be '110'. As another example, the audio processing device can generate a second audio signal by adding a second combination consisting of a first preset signal and a third preset signal to the first audio signal. In this case, the information expressed in binary may be '101'.

[0317] In one embodiment, the audio processing device can transmit the generated second audio signal to an audio output device.

[0318] In one embodiment, binary information obtainable from a combination of one or more preset signals may correspond to a channel layout for reproducing sound. An audio output device may reproduce sound through a channel layout corresponding to a combination of one or more preset signals.

[0319] For example, an audio output device may determine that a second audio signal includes a combination of a first preset signal and a second preset signal. The audio output device may obtain binary information of '110'. For example, the audio output device may reproduce sound through a 7.1.0 channel layout corresponding to '110'.

[0320] As another example, the audio output device may determine that the second audio signal includes a combination of the first preset signal and the third preset signal. The audio output device may obtain binary information for '101'. For example, the audio output device may reproduce sound through a 5.1.2 channel layout corresponding to '101'.

[0321] FIG. 15a is a graph illustrating a first acoustic signal related to sound reproduced through an LFE (Low Frequency Effect) channel according to an embodiment of the present disclosure. FIG. 15b is a graph illustrating a second acoustic signal different from the first acoustic signal according to an embodiment of the present disclosure.

[0322] For reference, FIGS. 15A and 15B are frequency-time graphs of an LFE channel audio signal among multi-channel audio signals transmitted from an audio processing device to an audio output device according to one embodiment. Specifically, FIG. 15A is a graph for an unmodified LFE channel audio signal, and FIG. 15B is a graph for an LFE channel audio signal modified by adding one or more preset signals.

[0323] For reference, Fig. 15a is a drawing for comparison with Fig. 15b, and is the same drawing as Fig. 6a, and the related explanations are the same, so they are simplified.

[0324] Referring to FIG. 15A, a graph for an unmodified LFE channel audio signal (160a) is illustrated. The LFE channel audio signal (160a) is an audio signal that can be reproduced through a channel for outputting low-frequency sound effects. The LFE channel audio signal (160a) may be generated in a low-frequency range. The LFE channel audio signal (160a) may include an audio signal having a low-band frequency. For example, the LFE channel audio signal (160a) may include an audio signal having a frequency band below 400 Hz.

[0325] Referring to FIG. 15b, a graph is shown for an LFE channel audio signal (160b) modified by adding a preset signal. The modified LFE channel audio signal (160b) may include an original LFE channel audio signal (161b) and one or more preset signals (162b, 163b). The modified LFE channel audio signal (160b) may be a combination of the original LFE channel audio signal (161b) and one or more preset signals (162b, 163b).

[0326] In one embodiment, the original LFE channel audio signal (161b) may mean an LFE channel audio signal before one or more preset signals (162b, 163b) are added, and may be identical to the unmodified LFE channel audio signal (160a) of FIG. 15a.

[0327] In one embodiment, one or more preset signals (162b, 163b) may be signals having a frequency range that is distinct from the LFE channel audio signal (161b). One or more preset signals (162b, 163b) may be signals having a high frequency range that is distinct from the low frequency range of the LFE channel. For example, the frequency range of one or more preset signals (162b, 163b) may not overlap with the frequency range of the LFE channel.

[0328] In one embodiment, the frequency domains of the preset signals may not overlap each other. The frequency domain of the first preset signal (162b) may not overlap with the frequency domain of the second preset signal (163b). The first preset signal (162b) may be distinguished from the second preset signal (163b). The audio output device may determine a combination of one or more preset signals by obtaining whether the first preset signal (162b) and the second preset signal (163b) whose frequency domains are distinguished are included, and may determine a channel layout corresponding to the combination of one or more preset signals. The audio output device may reproduce sound according to the determined channel layout.

[0329] In one embodiment, binary information of '1' or '0' may be determined depending on whether a preset signal is included in the LFE channel audio signal (160b). Taking the case illustrated in FIG. 15b as an example, since the LFE channel audio signal (160b) includes the first preset signal (162b), '1' may be determined in the first integer digit of the binary number. Since the LFE channel audio signal (160b) includes the second preset signal (163b), '1' may be determined in the second integer digit of the binary number. Since the third preset signal is not included in the frequency domain (165b) where the third preset signal is to be located in the LFE channel audio signal (160b), '0' may be determined in the third integer digit of the binary number. As a result, the LFE channel audio signal (160b) may include binary information of '110'.

[0330] An audio output device can reproduce sound through a channel layout corresponding to binary information. The binary information '110' described as being included in the LFE channel audio signal (160b) through Fig. 15b is merely an example, and various combinations of preset signals or other forms may be added to the LFE channel audio signal (160b) according to Table 2. The LFE channel audio signal (160b) may include information regarding various channel layouts.

[0331] FIG. 16 is a flowchart illustrating a method for preprocessing a first acoustic signal to generate a second acoustic signal according to an embodiment of the present disclosure. For convenience of explanation, details that overlap with those described using FIG. 13 are simplified or omitted.

[0332] For reference, Fig. 16 describes a preprocessing operation that reduces the amplitude of an audio signal, and Fig. 17 describes a postprocessing operation that restores the amplitude of a preprocessed audio signal.

[0333] Referring to FIG. 16, step S1330 of FIG. 13 may include step S1610 and step S1620.

[0334] In step S1610, the electronic device can reduce the amplitude of the first acoustic signal based on the amplitude of one or more preset signals.

[0335] In one embodiment, when a preset signal is added to a first audio signal to generate a second audio signal, the amplitude of the second audio signal may exceed the maximum allowable range of the audio system. Accordingly, the electronic device may reduce the amplitude of the first audio signal in advance.

[0336] In one embodiment, the electronic device can reduce the amplitude of the first audio signal based on the amplitude of one or more preset signals. When the preset signal is added to the first audio signal and the amplitude of the second audio signal exceeds the allowable range of the audio system, the exceeding amplitude of the second audio signal can be proportional to the amplitude of the one or more preset signals. Accordingly, the electronic device can reduce the amplitude of the first audio signal in advance in proportion to the amplitude of the one or more preset signals.

[0337] However, reducing the amplitude of an acoustic signal may also be expressed as suppressing or attenuating the acoustic signal, and such expressions or terms do not limit the present disclosure.

[0338] In step S1620, the electronic device can obtain a second audio signal by adding one or more preset signals to the reduced first audio signal. The description related to step S1620 is omitted as it overlaps with the description using step S1330 of FIG. 13.

[0339] FIG. 17 is a flowchart illustrating a method for recovering a first audio signal prior to preprocessing by post-processing a second audio signal according to an embodiment of the present disclosure. For convenience of explanation, details that overlap with those described using FIG. 13 are simplified or omitted.

[0340] Referring to FIG. 17, steps S1710 and S1720 may be performed after step S1340 of FIG. 13.

[0341] In step S1710, the electronic device can filter the second acoustic signal through a low pass filter.

[0342] In one embodiment, the second audio signal may be an audio signal to which a preset signal is added to the first audio signal. The second audio signal may be an audio signal to which a combination of one or more preset signals is added to the first audio signal. For example, the second audio signal may be a combination of the first audio signal and one or more preset signals. The first audio signal may include an LFE channel audio signal among the multi-channel audio signals.

[0343] In one embodiment, the audio output device can obtain an audio signal in a low frequency band by filtering a second audio signal through a low pass filter. By filtering the second audio signal, the first audio signal can be passed, and one or more preset signals can be blocked. For example, the audio output device can obtain an LFE channel audio signal by filtering the second audio signal through a low pass filter. At the same time, the audio output device can block one or more preset signals by filtering the second audio signal through the low pass filter.

[0344] In step S1720, the audio output device can generate an LFE output signal by amplifying the amplitude of the second audio signal based on the amplitude of one or more preset signals.

[0345] In one embodiment, when a preset signal is added to a first audio signal to generate a second audio signal, the amplitude of the second audio signal may exceed the maximum allowable range of the audio system. Therefore, the audio processing device may reduce the amplitude of the first audio signal in advance. The audio processing device may obtain a second audio signal by modifying the first audio signal whose amplitude has been reduced. The audio processing device may transmit the obtained second audio signal to an audio output device.

[0346] The audio output device can re-amplify the amplitude of a second audio signal obtained based on a first audio signal with a reduced amplitude. Accordingly, the audio output device can recover the first audio signal with a maintained amplitude without exceeding the maximum allowable amplitude range of the audio system.

[0347] In one embodiment, the audio output device can amplify the amplitude of the second audio signal based on the amplitude of one or more preset signals.

[0348] The audio output device can obtain a second audio signal by adding a preset signal to the first audio signal whose amplitude is reduced by step S1610. The audio output device can filter the second audio signal through a low-pass filter. By applying the low-pass filter to the second audio signal, the first audio signal can be passed, and one or more preset signals can be blocked. For example, the filtered second audio signal can be the same audio signal as the first audio signal.

[0349] The filtered second audio signal has a reduced amplitude, and the degree to which the amplitude of the filtered second audio signal is reduced may be proportional to the amplitude of one or more preset signals. The degree to which the amplitude of the filtered second audio signal is reduced may be proportional to the amplitude of one or more preset signals blocked by the low-pass filter. The audio output device may amplify the amplitude of the filtered second audio signal in proportion to the amplitude of one or more preset signals.

[0350] In one embodiment according to FIGS. 16 and 17, the amplitude of a first audio signal may be reduced before one or more preset signals are added. Thereafter, the amplitude of a second audio signal transmitted to an audio output device may be amplified again to generate an LFE output signal. This prevents clipping, a distortion phenomenon that occurs when the maximum allowable range of an audio system is exceeded when a preset signal is added to an audio signal.

[0351] FIG. 18 is a flowchart illustrating a method for interpreting multiple audio signals by post-processing discontinuities between two input audio signals, according to one embodiment of the present disclosure.

[0352] For reference, the graph of Fig. 18 is a graph that represents the amplitude of the signal along the vertical axis and time along the horizontal axis, and illustrates the form of an LFE channel audio signal output by an audio output device. In Fig. 18, a problem that occurs before post-processing an LFE channel audio signal is explained through a first graph (1810), and post-processing an LFE channel audio signal to solve the problem that has occurred is explained through a second graph (1820).

[0353] Referring to the first graph (1810) of FIG. 18, the audio output device can receive a first signal and a second signal.

[0354] In one embodiment, the first signal may include an audio signal to which one or more preset signals are added to an LFE channel audio signal transmitted by an audio processing device. The first signal may refer to an LFE channel audio signal obtained again as a result of filtering an audio signal to which one or more preset signals are added to an LFE channel audio signal through a low-pass filter.

[0355] In one embodiment, the first signal may be divided into a first section and a second section. The first section may refer to a past point in time when the first signal was post-processed and output by an audio output device. That is, the first signal of the first section has already been output by the audio output device. The second section may refer to a current point in time when the first signal was received by the audio output device. The first signal of the second section may refer to an audio signal before being post-processed. Here, the post-processing refers to post-processing in which the amplitude is amplified according to step S1720 of FIG. 17.

[0356] In one embodiment, the first signal in the first section may include an audio signal whose amplitude is amplified according to step S1720 of an LFE channel audio signal. The amplification of the amplitude of the LFE channel audio signal may offset the operation of reducing the amplitude according to step S1610. In the first section, the audio output device may output the LFE channel audio signal whose amplitude is restored.

[0357] In one embodiment, the second signal may include an audio signal received from an external audio device. The second signal may include an audio signal without a preset signal added. For example, the second signal may be an audio signal indicated as '000' as described in Table 2, without a preset signal added.

[0358] In one embodiment, the second signal may be divided into a second section and a third section. The second section may refer to the current time point at which the second signal is received by the audio output device. The second signal in the second section may refer to an audio signal before post-processing. Here, post-processing refers to post-processing in which the amplitude is amplified according to step S1720 of FIG. 17. The third section may refer to a future time point at which the second signal has not yet been input by the audio output device.

[0359] In one embodiment, an audio output device can continuously receive audio signals. The audio output device can divide the continuous audio signal into frames. The audio output device can obtain information about the audio signal for each frame and output sound corresponding to the audio signal. The third section may refer to frames from a future point in time that are not recognized by the audio output device.

[0360] However, the audio output device may not be able to distinguish between the first and second signals, as it only receives audio signals continuously and recognizes them frame by frame. Accordingly, the audio output device may obtain information about the audio signal corresponding to the frames of the second section. In the second section, the audio output device may not distinguish between the first and second signals within the second section.

[0361] For reference, the time corresponding to the audio signal of the second section is the present, the sound corresponding to the first signal included in the first section may be after being output, and the sound corresponding to the second signal included in the third section may be before being output.

[0362] In one embodiment, the first signal in the second section means an LFE channel audio signal that is passed through a low pass filter after the second audio signal is transmitted to an audio output device by reducing the amplitude of the first audio signal according to step S1610 of FIG. 16, adding a preset signal to the first audio signal whose amplitude has been reduced to obtain a second audio signal.

[0363] Due to the step of reducing the amplitude of the first audio signal, the amplitude of the first signal in the second section may be different from the amplitude of the first signal in the first section and the amplitude of the second signal in the second section. The first signal in the first section may be a signal that has already been output by applying an operation of amplifying the amplitude of the second audio signal according to step S1720, and thus is higher than the amplitude of the first signal in the second section. The second signal in the second section may be an audio signal from an external audio device for which the operation of reducing the amplitude according to step S1610 has not been performed, and thus may be higher than the amplitude of the first signal in the second section. Therefore, a problem occurs in which the amplitudes do not match between the end of the first signal in the first section and the beginning of the first signal in the second section, and in which the amplitudes do not match between the end of the first signal in the second section and the beginning of the second signal in the second section.

[0364] In addition, if an operation for amplifying the amplitude of the sound signal according to step S1720 is applied to the second section, the amplitude of the first signal in the first section and the amplitude of the first signal in the second section can be made to match, but a problem occurs in which the amplitude of the second signal in the second section and the amplitude of the second signal in the third section do not match.

[0365] Accordingly, referring to the second graph (1820) of FIG. 18, the audio output device can apply a smoothing filter to the audio signal of the second section. The smoothing filter can reduce rapid fluctuations in the amplitude of the audio signal. For example, the audio output device can use the smoothing filter to calculate the average amplitude of the audio signal within a certain range and generate an audio signal with a new amplitude value. However, the method of smoothing the audio signal is merely an example and does not limit the present disclosure.

[0366] In one embodiment according to FIGS. 16 and 17, the electronic device can control the amplitude of the audio signal to prevent clipping. As a result, a discontinuity phenomenon may occur between the audio signal within the frame and the audio signal outside the frame recognized by the audio output device. In one embodiment of FIG. 18, the audio output device can prevent the discontinuity phenomenon by applying a smoothing filter to the audio signal.

[0367] FIG. 19 is a diagram for explaining the configuration of an audio processing device for processing a multi-channel audio signal according to one embodiment of the present disclosure.

[0368] The audio processing device (1900) may include at least one memory (1910) and at least one processor (1930). However, the components of the audio processing device (1900) are not limited to the examples described above, and the audio processing device (1900) may include more or fewer components than the components described above.

[0369] The audio processing device (1900) can be implemented as a device capable of audio processing, such as a server, TV, camera, mobile phone, tablet PC, or laptop.

[0370] Although at least one memory (1910) and at least one processor (1930) are illustrated individually in FIG. 19, at least one memory (1910) and at least one processor (1930) may be implemented via a single hardware module (e.g., a chip).

[0371] At least one memory (1910) is configured to store various programs or data, and may be configured as a storage medium or a combination of storage media such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD. At least one memory (1910) may not exist separately and may be configured to be included in at least one processor (1930). At least one memory (1910) may be configured as a volatile memory, a non-volatile memory, or a combination of volatile memory and non-volatile memory. Programs or instructions for performing operations according to the embodiments described with reference to FIGS. 1 to 18 may be stored in at least one memory (1910). At least one memory (1910) may provide stored data to at least one processor (1930) upon request of at least one processor (1930).

[0372] It should be understood that the blocks and combinations of flowcharts in each flowchart can be executed by one or more computer programs containing computer-executable instructions. The one or more computer programs may be stored entirely in a single memory, or may be stored in separate portions across multiple different memories.

[0373] At least one processor (1930) controls a series of processes so that the audio processing device (1900) operates according to the embodiments described with reference to FIGS. 1 to 18, and may be configured with one or more processors. One or more processors included in at least one processor (1930) may be circuitry such as a System on Chip (SoC), an Integrated Circuit (IC), etc. In this case, one or more processors may be a general-purpose processor such as a CPU, an AP, a Digital Signal Processor (DSP), a graphics-only processor such as a GPU, a Vision Processing Unit (VPU), or an artificial intelligence-only processor such as an NPU. For example, when one or more processors are artificial intelligence-only processors, the artificial intelligence-only processor may be designed with a hardware structure specialized for processing a specific artificial intelligence model.

[0374] At least one processor (1930) can write data to at least one memory (1910), or read data stored in at least one memory (1910), and in particular, can process data according to predefined operation rules or artificial intelligence models by executing a program or at least one instruction stored in at least one memory (1910). Accordingly, at least one processor (1930) can perform operations described in the following embodiments, and operations described as being performed by the audio processing device (1900) or detailed components included in the audio processing device (1900) in the following embodiments can be regarded as being performed by at least one processor (1930) unless otherwise specifically described.

[0375] At least one memory (1910) can store one or more instructions for audio processing. At least one processor (1930) can obtain a first audio signal regarding sound reproduced through an LFE channel according to the instructions stored in at least one memory (1910), and obtain a second audio signal by modifying the first audio signal based on reproduction layout information. At least one processor (1930) can transmit the second audio signal modified from the first audio signal to an external device according to the instructions stored in at least one memory (1910).

[0376] At least one processor (1930) may perform at least some of the functions of the audio processing device (100, 400, 700) of FIG. 1, FIG. 8 or FIG. 12.

[0377] FIG. 20 is a diagram for explaining the configuration of an electronic device for outputting a multi-channel audio signal according to one embodiment of the present disclosure.

[0378] The audio output device (2000) may include at least one memory (2010) and at least one processor (2030). However, the components of the audio output device (2000) are not limited to the examples described above, and the audio output device (2000) may include more or fewer components than the components described above.

[0379] The audio output device (2000) can be implemented as a device capable of audio output, such as a sound bar, TV, mobile phone, tablet PC, or laptop.

[0380] Although at least one memory (2010) and at least one processor (2030) are illustrated individually in FIG. 20, at least one memory (2010) and at least one processor (2030) may be implemented via a single hardware module (e.g., a chip).

[0381] At least one memory (2010) is configured to store various programs or data, and may be configured as a storage medium or a combination of storage media such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD. At least one memory (2010) may not exist separately and may be configured to be included in at least one processor (2030). At least one memory (2010) may be configured as a volatile memory, a non-volatile memory, or a combination of volatile memory and non-volatile memory. Programs or instructions for performing operations according to the embodiments described with reference to FIGS. 1 to 18 may be stored in at least one memory (2010). At least one memory (2010) may provide stored data to at least one processor (2030) upon request of at least one processor (2030).

[0382] At least one processor (2030) controls a series of processes so that the audio output device (2000) operates according to the embodiments described with reference to FIGS. 1 to 18, and may be configured with one or more processors. In this case, one or more processors may be a general-purpose processor such as a CPU, an AP, a DSP (Digital Signal Processor), a graphics-only processor such as a GPU, a VPU (Vision Processing Unit), or an artificial intelligence-only processor such as an NPU. For example, when one or more processors are artificial intelligence-only processors, the artificial intelligence-only processor may be designed with a hardware structure specialized for processing a specific artificial intelligence model.

[0383] In one embodiment, at least one processor (1930) of FIG. 19 and at least one processor (2030) of FIG. 20 may control a series of processes to operate each device, as well as control a series of processes to operate each other's devices. For example, at least one processor (1930) of FIG. 19 may be a configuration that controls a series of processes to operate an audio output device (2000) according to the embodiments described above with reference to FIGS. 1 to 18. As another example, at least one processor (2030) of FIG. 20 may be a configuration that controls a series of processes to operate an audio processing device (1900) according to the embodiments described above with reference to FIGS. 1 to 18.

[0384] At least one memory (2010) can store one or more instructions for audio output. At least one processor (2030) can obtain a second audio signal according to the instructions stored in at least one memory (2010), and determine a channel layout for reproducing the sound by analyzing a combination of preset signals included in the second audio signal. At least one processor (2030) can reproduce the sound through the channel layout determined according to the instructions stored in at least one memory (2010). At least one processor (2030) can restore the sound by filtering the second audio signal according to the instructions stored in at least one memory (2010), and reproduce the restored sound through the determined channel layout.

[0385] At least one processor (2030) may perform at least some of the functions of the audio output device (300, 600, 900) of FIG. 1, FIG. 8 or FIG. 12.

[0386] Although the devices for processing and outputting multi-channel audio signals have been separately described through FIGS. 19 and 20, in one embodiment, part or all of the operations for processing and outputting multi-channel audio signals may be performed by the audio processing device of FIG. 19 or by the audio output device of FIG. 20.

[0387] An electronic device according to an embodiment may include at least one memory configured to store one or more instructions and at least one processor. By having the at least one processor execute a program stored in the memory or one or more instructions, the electronic device may obtain playback layout information related to sound reproduction using multiple channels. The electronic device may obtain a first audio signal related to sound reproduced through an LFE (Low Frequency Effect) channel among the multiple channels. The electronic device may obtain a second audio signal different from the first audio signal by modifying the first audio signal based on the playback layout information. The electronic device may transmit the second audio signal to an external device.

[0388] In one embodiment, the electronic device can obtain a second acoustic signal by adding one or more preset signals to a first acoustic signal by having at least one processor execute a program or one or more instructions stored in a memory.

[0389] In one embodiment, the LFE (Low Frequency Effect) channel may be a channel that outputs low-frequency sound effects. One or more preset signals may be signals having a frequency band higher than that of the first sound signal.

[0390] In one embodiment, the electronic device can obtain a second audio signal by adding at least one of a first preset signal, a second preset signal, and a third preset signal to a first audio signal based on reproduction layout information by causing at least one processor to execute a program or one or more instructions stored in a memory.

[0391] In one embodiment, the second audio signal may be a signal to which a combination of one or more preset signals corresponding to reproduction layout information is added within the first audio signal.

[0392] In one embodiment, the electronic device can reduce the amplitude of a first acoustic signal based on the amplitude of one or more preset signals by having at least one processor execute a program stored in the memory or one or more instructions. The electronic device can obtain a second acoustic signal by adding one or more preset signals to the reduced first acoustic signal by having at least one processor execute a program stored in the memory or one or more instructions.

[0393] In one embodiment, the playback layout information includes information about a channel layout corresponding to a combination consisting of eight channels, and the channel layout may include a 5.1.2 channel layout and a 7.1.0 channel layout.

[0394] An electronic device according to an embodiment may include a memory configured to store one or more instructions and at least one processor. The electronic device may receive an LFE (Low Frequency Effect) channel audio signal regarding sound reproduced through an LFE channel among a plurality of channels by the at least one processor executing a program stored in the memory or one or more instructions. The electronic device may determine a channel layout for reproducing the sound based on a signal obtained by applying the LFE channel audio signal to one or more band pass filters. The electronic device may output sound according to the signal obtained by applying the LFE channel audio signal to a low pass filter.

[0395] In one embodiment, the electronic device can obtain a combination of one or more preset signals by applying an LFE channel audio signal to one or more bandpass filters when determining a channel layout by having at least one processor execute a program or one or more instructions stored in a memory. The electronic device can determine the channel layout based on the combination of the one or more preset signals.

[0396] In one embodiment, the electronic device can generate an LFE output signal by amplifying the amplitude of an LFE channel audio signal based on the amplitude of one or more preset signals by causing at least one processor to execute a program stored in a memory or one or more instructions. The electronic device can output sound according to the generated LFE output signal.

[0397] In one embodiment, the LFE channel audio signal may include a combination of a first audio signal and one or more preset signals relating to sound reproduced through an LFE (Low Frequency Effect) channel among a plurality of channels.

[0398] According to one embodiment, a method for an electronic device to process an audio signal may include a step of obtaining playback layout information related to audio reproduction using a plurality of channels. The method may include a step of obtaining a first audio signal related to audio reproduced through a low frequency effect (LFE) channel among the plurality of channels. The method may include a step of obtaining a second audio signal different from the first audio signal by modifying the first audio signal based on the playback layout information. The method may include a step of transmitting the second audio signal from the electronic device to an external device.

[0399] In one embodiment, the step of obtaining the second acoustic signal may be obtaining the second acoustic signal by adding one or more preset signals to the first acoustic signal.

[0400] In one embodiment, the LFE (Low Frequency Effect) channel may be a channel that outputs low-frequency sound effects. Each of the one or more preset signals may be a signal having a frequency band higher than that of the first sound signal.

[0401] In one embodiment, the step of obtaining the second audio signal may be to obtain the second audio signal by adding at least one of a first preset signal, a second preset signal, and a third preset signal to the first audio signal based on reproduction layout information.

[0402] In one embodiment, the step of obtaining the second acoustic signal may include the step of reducing the amplitude of the first acoustic signal based on the amplitude of one or more preset signals. The step of obtaining the second acoustic signal may include the step of obtaining the second acoustic signal by adding one or more preset signals to the reduced first acoustic signal.

[0403] According to one embodiment, a method for an electronic device to output an audio signal may include receiving an LFE (Low Frequency Effect) channel audio signal regarding an audio sound reproduced through an LFE channel among a plurality of channels. The method may include a step of determining a channel layout for reproducing the audio sound based on a signal obtained by applying the LFE channel audio signal to one or more band pass filters. The method may include a step of outputting an audio sound according to a signal obtained by applying the LFE channel audio signal to a low pass filter.

[0404] In one embodiment, the step of determining the channel layout may include obtaining a combination of one or more preset signals by applying an LFE channel audio signal to one or more bandpass filters. The step of determining the channel layout may include determining the channel layout based on the combination of the one or more preset signals.

[0405] The method may include a combination of a first audio signal and one or more preset signals relating to sound reproduced through an LFE (Low Frequency Effect) channel among a plurality of channels, wherein the LFE channel audio signal is an LFE channel audio signal.

[0406] A non-transitory computer-readable recording medium having recorded thereon a program for performing any one of the methods according to one embodiment of the present disclosure on a computer may be provided.

[0407] An electronic device according to an embodiment of the present disclosure may include a memory configured to store one or more instructions and at least one processor. By having the at least one processor execute a program stored in the memory or one or more instructions, the electronic device may receive an LFE (Low Frequency Effect) channel audio signal regarding sound reproduced through an LFE channel among a plurality of channels. The electronic device may determine a channel layout for reproducing sound based on a signal obtained by applying the LFE channel audio signal to a band-pass filter. The electronic device may output sound according to the signal obtained by applying the LFE channel audio signal to a low-pass filter.

[0408] Various embodiments of the present disclosure may be implemented or supported by one or more computer programs, and the computer programs may be formed from computer-readable program code and embodied in a computer-readable medium. In the present disclosure, "application" and "program" may refer to one or more computer programs, software components, instruction sets, procedures, functions, objects, classes, instances, associated data, or portions thereof suitable for implementation in computer-readable program code. "Computer-readable program code" may include various types of computer code, including source code, object code, and executable code. "Computer-readable medium" may include various types of media that can be accessed by a computer, such as read-only memory (ROM), random access memory (RAM), a hard disk drive (HDD), a compact disc (CD), a digital video disc (DVD), or various types of memory.

[0409] Additionally, a device-readable storage medium may be provided in the form of a non-transitory storage medium. Here, a 'non-transitory storage medium' is a tangible device and may exclude wired, wireless, optical, or other communication links that transmit temporary electrical or other signals. Meanwhile, this 'non-transitory storage medium' does not distinguish between cases where data is permanently stored in the storage medium and cases where it is temporarily stored. For example, a 'non-transitory storage medium' may include a buffer where data is temporarily stored. A computer-readable medium may be any available medium that can be accessed by a computer, and may include both volatile and non-volatile media, and removable and non-removable media. A computer-readable medium includes a medium on which data can be permanently stored and a medium on which data can be stored and later overwritten, such as a rewritable optical disk or an erasable memory device.

[0410] According to one embodiment, the method according to various embodiments disclosed in the present document may be provided as included in a computer program product. The computer program product may be traded as a product between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., a compact disc read-only memory (CD-ROM)), or may be distributed online (e.g., downloaded or uploaded) through an application store or directly between two user devices (e.g., smartphones). In the case of online distribution, at least a portion of the computer program product (e.g., a downloadable app) may be temporarily stored or temporarily generated in a machine-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or an intermediary server.

[0411] The above description of the present disclosure is for illustrative purposes only, and those skilled in the art will appreciate that the present disclosure can be readily modified into other specific forms without altering the technical spirit or essential characteristics of the present disclosure. For example, suitable results can be achieved even if the described techniques are performed in a different order than the described method, and / or components of the systems, structures, devices, circuits, etc. described are combined or combined in a different form than the described method, or are replaced or substituted by other components or equivalents. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as being single may be implemented in a distributed manner, and similarly, components described as being distributed may be implemented in a combined form.

[0412] The scope of the present disclosure is indicated by the claims described below rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present disclosure.

Claims

1. At least one memory (1910) configured to store one or more instructions; and comprising at least one processor (1930), The electronic device (100) executes a program or one or more instructions stored in the memory by the at least one processor. Acquire playback layout information (130) related to sound reproduction using multiple channels, Obtaining a first sound signal (141) regarding sound reproduced through the LFE (Low Frequency Effect) channel among the above multiple channels, By modifying the first acoustic signal based on the above reproduction layout information, a second acoustic signal different from the first acoustic signal is obtained, An electronic device that transmits the second acoustic signal to an external device (300).

2. In paragraph 1, The electronic device, by causing at least one processor to execute a program or one or more instructions stored in the memory, An electronic device that obtains the second acoustic signal by adding one or more preset signals (150) to the first acoustic signal.

3. In paragraph 2, The above LFE (Low Frequency Effect) channel is a channel that outputs low-frequency sound effects. An electronic device, wherein said one or more preset signals are signals having a higher frequency band than said first acoustic signal.

4. In either of the second and third paragraphs, The electronic device, by causing at least one processor to execute a program or one or more instructions stored in the memory, An electronic device that obtains the second audio signal by adding at least one of a first preset signal, a second preset signal, and a third preset signal to the first audio signal based on the playback layout information.

5. In any one of the clauses 2 to 4, An electronic device wherein the second audio signal is a signal to which a combination of one or more preset signals corresponding to the reproduction layout information is added within the first audio signal.

6. In any one of the clauses 2 to 5, The electronic device, by causing at least one processor to execute a program or one or more instructions stored in the memory, reducing the amplitude of the first acoustic signal based on the amplitude of one or more preset signals; An electronic device that obtains the second acoustic signal by adding one or more preset signals to the reduced first acoustic signal.

7. In any one of paragraphs 1 to 6, An electronic device, wherein the above playback layout information includes information about a channel layout corresponding to a combination consisting of eight channels, and the channel layout includes a 5.1.2 channel layout and a 7.1.0 channel layout.

8. At least one memory (2010) storing one or more instructions; and comprising at least one processor (2030), The electronic device, by causing at least one processor to execute a program or one or more instructions stored in at least one memory, Receives an LFE channel audio signal regarding sound played through the LFE (Low Frequency Effect) channel among the above multiple channels, determining a channel layout for reproducing the sound based on a signal obtained by applying the LFE channel audio signal to one or more band pass filters; An electronic device that outputs sound according to a signal obtained by applying the above LFE channel audio signal to a low pass filter.

9. In a method for processing an acoustic signal by an electronic device, A step of obtaining playback layout information related to sound reproduction using multiple channels; A step of obtaining a first sound signal regarding sound reproduced through an LFE (Low Frequency Effect) channel among the above multiple channels; A step of obtaining a second acoustic signal different from the first acoustic signal by modifying the first acoustic signal based on the reproduction layout information; and A method comprising the step of transmitting the second acoustic signal from the electronic device to an external device.

10. In paragraph 9, A method wherein the step of obtaining the second acoustic signal comprises obtaining the second acoustic signal by adding one or more preset signals to the first acoustic signal.

11. In paragraph 10, The above LFE (Low Frequency Effect) channel is a channel that outputs low-frequency sound effects. A method wherein each of said one or more preset signals is a signal having a frequency band higher than that of said first acoustic signal.

12. In any one of paragraphs 10 and 11, A method according to claim 1, wherein the step of obtaining the second audio signal comprises obtaining the second audio signal by adding at least one of a first preset signal, a second preset signal, and a third preset signal to the first audio signal based on the reproduction layout information.

13. In any one of paragraphs 10 to 12, The step of obtaining the second acoustic signal is: A step of reducing the amplitude of the first acoustic signal based on the amplitude of the one or more preset signals; and A method comprising the step of obtaining the second acoustic signal by adding the one or more preset signals to the reduced first acoustic signal.

14. A method for an electronic device to output an acoustic signal, A step of receiving an LFE channel audio signal regarding sound reproduced through an LFE (Low Frequency Effect) channel among multiple channels; A step of determining a channel layout for reproducing the sound based on a signal obtained by applying the LFE channel audio signal to one or more band pass filters; and A method comprising the step of outputting sound according to a signal obtained by applying the above LFE channel audio signal to a low pass filter.

15. A computer-readable recording medium having recorded thereon a program executable by at least one processor to perform any one of the methods of claims 9 to 14.

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