KR102709737B1 - Apparatus for transmitting audio sigal and controlling method thereof - Google Patents

Abstract

According to one embodiment of the present invention, an electronic device includes: a memory for storing audio signal data; and a processor, wherein the processor may be configured to process the audio signal by dividing a frequency band corresponding to the audio signal into a plurality of sub-bands, allocating a first bit to a first sub-band to quantize a first sub-band among the plurality of sub-bands, determining a first headroom of the first sub-band based on a bandwidth of the first sub-band and the allocated first bit, applying the determined first headroom to the first sub-band among the plurality of sub-bands, and applying a second headroom having a different value from the first headroom to at least some of the remaining sub-bands. In addition to this, various embodiments are possible that can be understood through the specification.

Description

{APPARATUS FOR TRANSMITTING AUDIO SIGAL AND CONTROLLING METHOD THEREOF}

The present invention relates to an electronic device for transmitting an audio signal and a method for controlling the electronic device.

An audio signal generated in an analog form is converted into a digital signal through a sampling and quantization process, and the converted digital signal is encoded and can be transmitted to a user who ultimately consumes the audio signal. An electronic device that receives the encoded audio signal can decode the audio signal, perform a dequantization and inverse conversion process, and output it to the user.

When encoding audio signals in electronic devices, the algorithm focuses on maximizing the degree to which the compressed signal is indistinguishable from the original by human senses, rather than minimizing the mathematical error between audio signals. Very low or high frequency components that are inaudible to humans in the audio signal can be removed during the encoding process. Removing specific frequency components from the audio signal can be more efficient in processing the audio signal in the frequency domain than in the time domain.

When encoding and transmitting an audio signal in digital form, it is compressed to reduce the amount of data in the audio signal, and when compressing an audio signal, the energy value of the audio signal in a specified frequency band is quantized and determined to a specific value. If an error occurs during the quantization process, the energy value is determined to be an incorrect value, and if an incorrectly quantized audio signal is received and output, a distorted audio signal may be output.

In particular, a device that receives and outputs an audio signal has a maximum value that can be output, and if an audio signal including an energy level value higher than the maximum value is output, the device that outputs the audio signal may be damaged. The device that transmits or receives an audio signal may uniformly control the entire frequency band of the audio signal so as not to exceed the maximum value that can be output. When the entire frequency band of the audio signal is uniformly controlled, energy that does not need to be controlled can be uniformly removed because the energy included in each frequency band is different. Accordingly, the device that outputs an audio signal may output an audio signal of low quality (e.g., low output).

Various embodiments of the present invention provide an electronic device that analyzes energy level values by frequency band and controls the energy level values based on the analyzed energy level values, and a control method of the electronic device.

An electronic device according to the present invention comprises: a memory for storing audio signal data; and a processor, wherein the processor is configured to process the audio signal by dividing a frequency band corresponding to the audio signal into a plurality of sub-bands, allocating a first bit to a first sub-band to quantize the first sub-band among the plurality of sub-bands, determining a first headroom of the first sub-band based on a bandwidth of the first sub-band and the allocated first bit, applying the determined first headroom to the first sub-band among the plurality of sub-bands, and applying a second headroom having a different value from the first headroom to at least some of the remaining sub-bands.

An electronic device according to the present invention may be configured such that the processor determines an energy level value of the first sub-band based on a bandwidth of the first sub-band and the allocated first bit, and determines a range higher than the determined energy level value as the first headroom within a range capable of outputting the audio signal.

An electronic device according to the present invention may be configured such that the processor determines a first maximum energy threshold based on a bandwidth of the first sub-band and the allocated first bit, and determines the first headroom of the first sub-band using the first maximum energy threshold.

An electronic device according to the present invention may be configured such that the processor determines a first quantization threshold value by quantizing the first maximum energy threshold value using the first bit, quantizes the first sub-band using the first bit and determines a first quantization level value with the quantized first sub-band, and determines a lower value of the first energy level value and the first quantization threshold value as the quantized level value of the first sub-band to determine the first headroom of the first sub-band.

An electronic device according to the present invention may be configured such that the processor determines a ratio of the first maximum energy threshold value to a maximum energy value of the first sub-band, and determines an energy level value of the determined ratio of the first energy level value of the first sub-band as the energy level value of the first sub-band to determine a first headroom of the first sub-band.

An electronic device according to the present invention may be configured such that the processor quantizes each of the plurality of sub-bands to which headroom is applied, and processes an audio signal in which each of the plurality of sub-bands is quantized.

An electronic device according to the present invention may be configured such that the processor allocates a second bit less than the first bit to quantize a second sub-band among the plurality of sub-bands, and determines the second maximum energy threshold value less than the first maximum energy threshold value based on a bandwidth of the second sub-band and the allocated second bit.

An electronic device according to the present invention may be configured such that the processor determines the first maximum energy threshold of the first sub-band according to a method of encoding the audio signal using a bandwidth of the first sub-band and the allocated first bit.

An electronic device according to the present invention may be configured such that the memory stores a maximum energy threshold value determined based on bandwidths of the plurality of sub-bands and bits allocated to the plurality of sub-bands, and the processor may be configured such that, when determining the first maximum energy threshold value of the first sub-band, a value corresponding to the bandwidth of the first sub-band and the allocated first bit among the maximum energy threshold values stored in the memory is determined as the first maximum energy threshold value of the first sub-band.

A control method of an electronic device according to the present invention may include: an operation of dividing a frequency band corresponding to an audio signal into a plurality of subbands; an operation of allocating a first bit to a first subband among the plurality of subbands in order to quantize the first subband; an operation of determining a first headroom of the first subband based on a bandwidth of the first subband and the allocated first bit; and an operation of processing the audio signal by applying the determined first headroom to the first subband among the plurality of subbands and applying a second headroom having a different value from the first headroom to at least some of the remaining subbands.

A control method of an electronic device according to the present invention may include: an operation of determining the first headroom of the first sub-band; an operation of determining an energy level value of the first sub-band based on a bandwidth of the first sub-band and the allocated first bit; and an operation of determining an energy range higher than the determined energy level value as the first headroom within a range capable of outputting the audio signal.

A control method of an electronic device according to the present invention may include: an operation of determining the first headroom of the first sub-band; an operation of determining a first maximum energy threshold based on a bandwidth of the first sub-band and the allocated first bit; and an operation of determining the first headroom of the first sub-band using the first maximum energy threshold.

A control method of an electronic device according to the present invention comprises: determining a first quantization threshold value by quantizing the first maximum energy threshold value using the first bit; quantizing the first sub-band using the first bit; and using the quantized first sub-band. The method may further include an operation of determining a first quantization level value; and an operation of determining the first headroom of the first sub-band using the first maximum energy threshold value; may include an operation of determining the first headroom of the first sub-band by determining a lower value of the first energy level value and the first quantization threshold value as the quantized level value of the first sub-band.

A control method of an electronic device according to the present invention may include: an operation of determining the first headroom of the first sub-band; an operation of determining a ratio of the first maximum energy threshold value to a maximum energy value of the first sub-band; and an operation of determining the first headroom of the first sub-band by determining an energy level value of the determined ratio of the first energy level value as an energy level value of the first sub-band.

A method for controlling an electronic device according to the present invention may include: an operation of processing an audio signal by applying headroom to the plurality of sub-bands; an operation of quantizing each of the plurality of sub-bands to which the headroom is applied; and an operation of processing an audio signal in which level values of each of the plurality of sub-bands are quantized.

An electronic device according to the present invention comprises: a memory for storing audio signal data; and a processor, wherein the processor may be configured to process the audio signal by dividing a frequency band corresponding to the audio signal into a plurality of sub-bands, determining a first headroom of a first sub-band based on a bandwidth of a first sub-band among the plurality of sub-bands, applying the determined first headroom to the first sub-band among the plurality of sub-bands, and applying a second headroom having a different value from the first headroom to at least some of the remaining sub-bands.

An electronic device according to the present invention may be configured such that the processor determines a first maximum energy threshold based on a bandwidth of the first sub-band, and determines the first headroom of the first sub-band using the first maximum energy threshold.

An electronic device according to the present invention may be configured such that the processor determines a ratio of the first maximum energy threshold value to a maximum energy value of the first sub-band, and determines an energy level value of the determined ratio of the first energy level value of the first sub-band as the energy level value of the first sub-band to determine a first headroom of the first sub-band.

An electronic device according to the present invention may be configured such that the processor determines the first maximum energy threshold value of the first sub-band according to a processing method for outputting the encoded audio signal using a bandwidth of the first sub-band.

An electronic device according to the present invention may be configured such that the memory stores a maximum energy threshold value determined based on bandwidths of the plurality of sub-bands, and the processor may be configured such that, when determining the first maximum energy threshold value of the first sub-band, a value corresponding to the bandwidth of the first sub-band among the maximum energy threshold values stored in the memory is determined as the first maximum energy threshold value of the first sub-band.

An electronic device for transmitting an audio signal of the present invention separates a frequency band for an audio signal into a plurality of sub-bands, analyzes an energy level value of each of the separated sub-bands to determine a maximum energy threshold value, and applies different headrooms to the plurality of frequency bands using the maximum energy threshold value, thereby preventing clipping that occurs when outputting an audio signal and minimizing loss that may occur when compressing an audio signal, thereby enabling a second electronic device to output a high-quality audio signal.

In addition, the function of setting the headroom differently for each of the multiple sub-bands of the first electronic device is implemented by a simple algorithm of comparing energy level values or multiplying ratios, which enables fast processing and can be easily applied to small electronic devices.

In addition, various effects may be provided that are directly or indirectly identified through this document.

FIG. 1 is a diagram illustrating an audio signal transmission and reception system according to various embodiments of the present invention.
FIG. 2 is a graph showing noise generated when an electronic device according to various embodiments of the present invention encodes an audio signal.
FIG. 3 is a graph showing the energy level of an audio signal of an electronic device according to various embodiments of the present invention.
FIG. 4 is a block diagram showing the configuration of an electronic device according to an embodiment of the present invention.
FIG. 5 is a block diagram illustrating a configuration of an electronic device that determines headroom based on the bandwidth of a sub-band and allocated bits according to one embodiment of the present invention.
FIG. 6 is a block diagram illustrating a configuration of an electronic device that determines headroom based on the bandwidth of a sub-band and allocated bits according to one embodiment of the present invention.
FIG. 7 is a graph showing determining energy levels for each sub-band of an electronic device according to an embodiment of the present invention.
FIG. 8 is a block diagram showing the configuration of an electronic device that determines headroom based on the bandwidth of a sub-band and allocated bits in a preprocessing process according to an embodiment of the present invention.
FIG. 9 is a block diagram showing the configuration of an electronic device that determines headroom based on the bandwidth of a sub-band in a post-processing process according to an embodiment of the present invention.
FIG. 10 is a flowchart illustrating a method for controlling an electronic device for encoding an audio signal according to an embodiment of the present invention.
FIG. 11 illustrates electronic devices within a network environment according to various embodiments.
FIG. 12 shows a block diagram of an electronic device according to an embodiment of the present invention.

Hereinafter, various embodiments of the present invention will be described with reference to the attached drawings. However, it should be understood that this is not intended to limit the present invention to specific embodiments, but includes various modifications, equivalents, and/or alternatives of the embodiments of the present invention. In connection with the description of the drawings, similar reference numerals may be used for similar components.

In this document, the expressions "have", "can have", "include", or "may include" indicate the presence of a feature (e.g., a numerical value, function, operation, or component such as a part), but do not exclude the presence of additional features.

In this document, the expressions "A or B", "at least one of A and/or B", or "one or more of A or/and B" can include all possible combinations of the items listed together. For example, "A or B", "at least one of A and B", or "at least one of A or B" can all refer to cases where (1) at least one A is included, (2) at least one B is included, or (3) both at least one A and at least one B are included.

The expressions "first", "second", "first", or "second" used in this document can describe various components, regardless of order and/or importance, and are only used to distinguish one component from another, but do not limit the components. For example, a first user device and a second user device can represent different user devices, regardless of order or importance. For example, without departing from the scope of the rights set forth in this document, a first component can be named a second component, and similarly, a second component can also be renamed as a first component.

When it is stated that a component (e.g., a first component) is "(operatively or communicatively) coupled with/to" or "connected to" another component (e.g., a second component), it should be understood that the component can be directly coupled to the other component, or can be connected via another component (e.g., a third component). On the other hand, when it is stated that a component (e.g., a first component) is "directly coupled to" or "directly connected to" another component (e.g., a second component), it should be understood that no other component (e.g., a third component) exists between the component and the other component.

The expression "configured to" as used herein can be used interchangeably with, for example, "suitable for", "having the capacity to", "designed to", "adapted to", "made to", or "capable of". The term "configured to" does not necessarily mean only that which is "specifically designed to" in terms of hardware. Instead, in some contexts, the expression "a device configured to" can mean that the device is "capable of" doing something together with other devices or components. For example, the phrase "a processor configured (or set) to perform A, B, and C" can mean a dedicated processor (e.g., an embedded processor) to perform those operations, or a generic-purpose processor (e.g., a CPU or application processor) that can perform those operations by executing one or more software programs stored in a memory device.

The terms used in this document are used only to describe specific embodiments and may not be intended to limit the scope of other embodiments. The singular expression may include the plural expression unless the context clearly indicates otherwise. The terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by a person of ordinary skill in the art described in this document. Among the terms used in this document, terms defined in general dictionaries may be interpreted as having the same or similar meaning in the context of the related technology, and shall not be interpreted in an ideal or excessively formal meaning unless explicitly defined in this document. In some cases, even if a term is defined in this document, it cannot be interpreted to exclude the embodiments of this document.

An electronic device according to various embodiments of the present document may include at least one of, for example, a smartphone, a tablet personal computer (PC), a mobile phone, a video phone, an e-book reader, a desktop PC, a laptop PC, a netbook computer, a workstation, a server, a personal digital assistant (PDA), a portable multimedia player (PMP), an MP3 player, a mobile medical device, a camera, or a wearable device. According to various embodiments, the wearable device may include at least one of an accessory type (e.g., a watch, a ring, a bracelet, an anklet, a necklace, glasses, a contact lens, or a head-mounted device (HMD)), a fabric or clothing-integrated type (e.g., an electronic garment), a body-attached type (e.g., a skin pad or a tattoo), or a bio-implantable type (e.g., an implantable circuit).

In some embodiments, the electronic device may be a home appliance. The home appliance may include at least one of, for example, a television, a Digital Video Disk player (DVD player), an audio, a refrigerator, an air conditioner, a vacuum cleaner, an oven, a microwave oven, a washing machine, an air purifier, a set-top box, a home automation control panel, a security control panel, a TV box (e.g., Samsung HomeSync™, Apple TV™, or Google TV™), a game console (e.g., Xbox™, PlayStation™), an electronic dictionary, an electronic key, a camcorder, or an electronic picture frame.

In another embodiment, the electronic device may be any of various medical devices (e.g., various portable medical measuring devices (such as blood glucose meters, heart rate monitors, blood pressure monitors, or body temperature monitors), magnetic resonance angiography (MRA), magnetic resonance imaging (MRI), computed tomography (CT), a camera, or an ultrasound device), a navigation device, a satellite navigation system (a Global Navigation Satellite System (GNSS)), an event data recorder (EDR), a flight data recorder (FDR), an automobile infotainment device, electronic equipment for ships (e.g., a navigation device for ships, a gyro compass, etc.), avionics, a security device, a head unit for a vehicle, an industrial or household robot, an automatic teller's machine (ATM) of a financial institution, a point of sales (POS) of a store, or an internet of things device (e.g., a light bulb, various sensors, an electric or gas meter, a sprinkler device, a fire alarm, It may include at least one of the following: a thermostat, a streetlight, a toaster, exercise equipment, a hot water tank, a heater, a boiler, etc.

According to some embodiments, the electronic device may include at least one of a piece of furniture or a part of a building/structure, an electronic board, an electronic signature receiving device, a projector, or various measuring devices (e.g., a water, electricity, gas, or radio wave measuring device, etc.). In various embodiments, the electronic device may be a combination of one or more of the various devices described above. The electronic device according to some embodiments may be a flexible electronic device. In addition, the electronic device according to the embodiments of the present document is not limited to the devices described above, and may include new electronic devices according to technological advancement.

Hereinafter, electronic devices according to various embodiments are described with reference to the attached drawings. In this document, the term user may refer to a person using an electronic device or a device using an electronic device (e.g., an artificial intelligence electronic device).

FIG. 1 is a diagram illustrating an audio system according to various embodiments of the present invention.

Referring to FIG. 1, an audio system may include a first electronic device (10) and a second electronic device (20). The first electronic device (10) may be a source device (e.g., a smartphone) that transmits an audio signal to the second electronic device (20). The second electronic device (20) may be an output device (e.g., a speaker device) that receives an audio signal from the first electronic device (10) and outputs the audio signal.

A first electronic device (10) can transmit an audio signal to a second electronic device (20). For example, the first electronic device (10) can transmit audio signal data stored internally (e.g., stored in a memory) to the second electronic device (20). As another example, the first electronic device (10) can receive audio signal data from an external device and transmit the audio signal data to the second electronic device (20).

According to one embodiment, when the first electronic device (10) transmits an audio signal to the second electronic device (20), the first electronic device (10) may compress the audio signal using a specified compression method and transmit the audio signal. For example, the first electronic device (10) may remove a portion of the audio signal according to a lossy compression method, compress the audio signal from which the portion has been removed, and transmit the compressed audio signal to the second electronic device (20). In other words, a portion of the compressed audio signal may be lost. The specified compression method may include, for example, MP3 (MPEG (moving picture experts group) layer 3), AC-3 (audio coding-3), ASF (advanced streaming format), etc. In addition, when the first electronic device (10) is connected to the second electronic device (20) via Bluetooth, the specified compression method may include any one of SBC (subband coding), AAC (advanced audio codec), and apt-X.

The second electronic device (20) can receive and output an audio signal from the first electronic device (10). For example, the second electronic device (20) can receive a compressed audio signal, decompress the compressed audio signal, and output the decompressed audio signal. According to one embodiment, the second electronic device (20) can decompress the compressed audio signal in a decompressing manner corresponding to the compression manner of the first electronic device (10).

According to one embodiment, the second electronic device (20) can post-process the audio signal. For example, the second electronic device (20) can equalize the decompressed audio signal to suit the user's taste through an EQ (equalizer). As another example, the second electronic device (20) can restore a high-frequency region signal of the decompressed audio signal. The decompressed audio signal may have a high-frequency region signal lost during the process of being compressed by, for example, the first electronic device (10). The second electronic device (20) can restore the audio signal from which the high-frequency region signal is lost.

According to one embodiment, the second electronic device (20) may have a maximum value (e.g., peak value) of energy that can output an audio signal. If the second electronic device (20) outputs an audio signal that includes energy higher than the maximum value of energy, it cannot output a distorted audio signal. Accordingly, the first electronic device (10) may adjust the audio signal to be transmitted so that the energy level value of the audio signal transmitted to the second electronic device (20) does not exceed the maximum energy value.

FIGS. 2A and 2B are graphs showing noise generated when an electronic device according to various embodiments of the present invention encodes an audio signal.

Referring to FIG. 2a, the first electronic device (10) can encode and transmit an audio signal having a size of -1 dB representing 0 to 24 kHz. For example, the first electronic device (10) can be connected to the second electronic device (20) via Bluetooth, and can encode an audio signal in the SBC (subband coding) method and transmit it to the second electronic device (20).

According to one embodiment, the first electronic device (10) may divide the frequency band corresponding to the audio signal into a plurality of sub-bands (b). For example, the first electronic device (10) may divide the frequency band corresponding to the audio signal into four sub-bands (b1, b2, b3, b4). According to one embodiment, the first electronic device (10) may allocate bits for quantizing energy level values differently for each of the sub-bands (b1, b2, b3, b4). For example, the first electronic device (10) may allocate many bits to a frequency band (b1) having high sensitivity and containing a lot of information (e.g., 2.5 to 5 kHz) within the human audible frequency band (e.g., 20 to 22 kHz), and may allocate few bits to a frequency band (b2, b3, b4) having somewhat lower sensitivity and containing little information.

Referring to FIG. 2b, when an audio signal is encoded by the first electronic device (10), noise may be generated. The amount of noise generated may vary depending on the bits allocated to the corresponding frequency band. For example, noise (n1) generated in a frequency band (b1) to which many bits are allocated may be less than noise (n2, n3, n4) generated in a frequency band (b2, b3, b4) to which few bits are allocated. Accordingly, an audio signal encoded by the first electronic device (10) may have a quantized level value increase (e.g., -1 dB or more) in a frequency band (b2, b3, b4) to which few bits are allocated.

FIG. 3 is a graph showing the energy level of an audio signal of an electronic device according to various embodiments of the present invention.

Referring to FIG. 3, the second electronic device (20) can normally output an audio signal having an energy level value within a dynamic range (31). If the energy level value of the audio signal is higher than the peak level (or peak value) (32) or lower than the noise level (33), the second electronic device (20) may operate abnormally (e.g., distortion (32´), noise (33´)). Accordingly, headroom and footroom can be set so that the second electronic device (20) can stably output the received audio signal. The audio signal to which the headroom and footroom are applied can be formed of an energy level value between the operation level (34) and the minimum signal level (35) (36).

The first electronic device (10) may apply headroom to the audio signal so as not to transmit an audio signal having an energy level value higher than a clipping level (32) to the second electronic device (20). The headroom may be determined to be a range higher than an average level value of energy of the audio signal (e.g., an RMS (root mean square) value of the audio signal) in consideration of a range in which the second electronic device (20) can output the audio signal. For example, the headroom may be determined to be a range higher than an energy level value of the audio signal and lower than a peak value of the second electronic device (20).

When applying the same headroom to the entire frequency band corresponding to the audio signal, the first electronic device (10) can set the headroom based on a sub-band to which a relatively small number of bits are allocated. Accordingly, the energy level value of the sub-band to which a relatively large number of bits are allocated is reduced beyond a necessary range, and the second electronic device (20) can receive an audio signal with low output (or low sound quality). The first electronic device (10) of the present invention can prevent the energy level value from being reduced beyond a necessary range by checking the energy level value of the sub-band when compressing the audio signal and applying a different amount of audio signal loss for each sub-band.

FIG. 4 is a block diagram showing the configuration of an electronic device according to an embodiment of the present invention.

Referring to FIG. 4, the first electronic device (10) may include an analog digital convertor (ADC) (100), an encoder (200), and a transmission module (300).

The signal input to the first electronic device (100) may be an analog signal or a digital signal. According to one embodiment, when the analog signal (e.g., user voice) is input, the first electronic device (100) may transmit the analog signal to the ADC (100). According to one embodiment, when the digital signal is input, the first electronic device (100) may transmit the digital signal to the encoder (200) without going through the processing process of the ADC (100). For example, when the first electronic device (10) plays a digital sound file (e.g., an MP3 file, etc.) stored in a memory, the digital signal of the digital sound file may not go through the processing process of the ADC (100).

The ADC (100) can convert an input analog signal into a digital signal. For example, the ADC (100) can extract samples of an input analog audio signal at regular time intervals, change the amplitude of the extracted sample to a designated representative value, and convert the designated representative value into a digital code to generate a digital audio signal.

The encoder (200) can compress the generated digital signal. For example, the encoder (200) can compress the digital audio signal according to a specified compression method (or codec). According to one embodiment, the encoder (200) can generate a bitstream using the digital signal compressed according to the specified compression method.

The transmission module (300) can transmit the generated bitstream to an external device. For example, the transmission module (300) can be wirelessly connected to the external device and transmit the bitstream to the external device.

FIG. 5 is a block diagram illustrating a configuration of an electronic device that determines headroom based on the bandwidth of a sub-band and allocated bits according to one embodiment of the present invention.

Referring to FIG. 5, the encoder (200) may include a frequency spectrum generation module (210), a psychoacoustic modeling module (220), a bit allocation module (230), a first quantization module (240), a maximum energy threshold value determination module (250), a second quantization module (260), an energy level determination module (270), and an encoding module (280).

The frequency spectrum generation module (210) can convert an audio signal converted into a digital signal into a signal in the frequency domain. The frequency spectrum generation module (210) can convert the audio signal in the time domain into a signal in the frequency domain according to a compression method.

According to one embodiment, the frequency spectrum generation module (210) can divide a frequency band corresponding to an audio signal converted into the frequency domain signal into a plurality of sub-bands (b). The frequency spectrum generation module (210) can separate the frequency band corresponding to the audio signal into a specified frequency bandwidth (bw) according to a compression method. For example, the frequency spectrum module (210) can separate a first sub-band (b1) and a second sub-band (b2) among the plurality of sub-bands (b) into a first frequency bandwidth (bw1) and a second frequency bandwidth (bw2).

According to one embodiment, the frequency spectrum generation module (210) can determine energy level values of a plurality of sub-bands (b). For example, the frequency spectrum generation module (210) can determine a representative value for each of a plurality of sub-bands (b) of the audio signal converted into the frequency domain signal, and determine the determined representative value as an energy level value (E) of the plurality of sub-bands (b). For example, a first sub-band (b1) of the plurality of sub-bands (b) can be determined as a first energy level value (E1), and a second sub-band (b2) of the plurality of sub-bands (b) can be determined as a second energy level value (E2). The first energy level value (E1) and the second energy level value (E2) can be different from each other. Accordingly, the frequency spectrum generation module (210) can generate an energy level frequency spectrum in which the plurality of sub-bands (b) are represented by their respective energy level values (E).

According to one embodiment, the psychoacoustic modeling module (220) can analyze an audio signal converted into a digital signal by considering human hearing characteristics. For example, the psychoacoustic modeling module (220) can analyze a major frequency band by considering the human audible frequency band, sensitivity, and amount of included information in the audio signal by considering the absolute threshold of hearing (ATH) and the shielding effect of the audio signal. The major frequency band may be, for example, a frequency band having high sensitivity and including a lot of information within the audible frequency band that a human can hear. According to one embodiment, the psychoacoustic modeling module (220) can change the audio signal in the time domain into a signal in the frequency domain by using FFT (fast Fourier transform) in order to analyze the audio signal.

According to one embodiment, the bit allocation module (230) may allocate bits (ba) to each of a plurality of sub-bands (b) based on information analyzed by the psychoacoustic modeling module (220) for the audio signal. For example, the bit allocation module (230) may allocate more bits to a sub-band included in the main frequency band analyzed by the psychoacoustic modeling module (220) than to a sub-band not included in the main frequency band. The first bit (ba1) allocated to the first sub-band (b1) included in the main frequency band may be allocated more bits than the second bit (ba2) allocated to the second sub-band (b2) not included in the main frequency band, for example. A sub-band to which more bits are allocated by the bit allocation module (230) may have an energy level value displayed more accurately than a sub-band to which fewer bits are allocated during quantization.

According to one embodiment, the first quantization module (240) can quantize an energy level frequency spectrum. The first quantization module (240) can quantize an energy level value (E) of each of the plurality of sub-bands (b). For example, the first quantization module (240) can determine the energy level value (E) of each of the plurality of sub-bands (b) as a specified size. The specified size can be determined, for example, according to bits (ba) allocated to each of the plurality of sub-bands (b).

According to one embodiment, the first quantization module (240) can quantize the energy level value (E) of each of the plurality of sub-bands (b) into the allocated bits (ba). For example, the first quantization module (240) can quantize the first energy level value (E1) of the first sub-band (b1) using the first bit (ba1) to determine the first quantization level value. The first quantization module (240) can quantize the second energy level value (E2) of the second sub-band (b2) using the second bit (ba2) to determine the second quantization level value.

The first quantization module (240) can quantize the energy level value (E) of a sub-band to which more bits are allocated more accurately than the energy level value (E) of a sub-band to which fewer bits are allocated. For example, the first quantization level value of the first sub-band (b1) can determine the quantization level value more accurately than the second quantization level value of the second sub-band (b2) to which fewer bits are allocated than the first sub-band (b1).

The maximum energy threshold value determination module (250) can determine the maximum energy threshold value (E_Th) of each of the plurality of sub-bands (b) based on the allocated bits (ba) and the frequency bandwidth (bw) of the sub-bands. The maximum energy threshold value determination module (250) can determine the maximum energy threshold value (E_Th) by using the allocated bits (ba) and the frequency bandwidth (bw) of the sub-bands according to the compression method. For example, the maximum energy threshold value determination module (250) can determine the maximum energy threshold value (E_Th) by using the following mathematical equation.

Here, c1, c2, c3, and c4 may be constants determined according to a compression method (or codec), a bitrate, etc. The maximum energy threshold value determination module (250) may determine a first maximum energy threshold value (E_Th1) of the first sub-band (b1) using, for example, a first frequency bandwidth (bw1) and a first bit (ba1), and may determine a second maximum energy threshold value (E_Th2) of the second sub-band (b2) using a second frequency bandwidth (bw2) and a second bit (ba2). The first maximum energy threshold value (E_Th1) and the second maximum energy threshold value (E_Th2) may be different from each other. As another example, the maximum energy threshold value determination module (250) may determine the maximum energy threshold value (E_Th) of each of the plurality of sub-bands (b) as a specified value (or a predetermined value). The above-mentioned specified value may be, for example, a maximum energy threshold value (E_th) determined based on a bandwidth (bw) of a plurality of sub-bands (b) and bits (ba) allocated to the plurality of sub-bands (b). The above-mentioned specified value may be stored in a memory as a look-up table. The maximum energy threshold value determination module (250) may determine a specified value corresponding to a first frequency bandwidth (bw1) and a first bit (ba1) as a first maximum energy threshold value (E_Th1) of the first sub-band (b1), and may determine a specified value corresponding to a second frequency bandwidth (bw2) and a second bit (ba2) as a second maximum energy threshold value (E_th2) of the second sub-band (b2).

In another embodiment, the maximum energy threshold value determination module (250) may determine the maximum energy threshold value (E_Th) of all of the plurality of sub-bands (b) to be the same value. The same maximum energy threshold value (E_Th) may be determined, for example, by considering the energy levels of the plurality of sub-bands (b) (e.g., based on the allocated bits (ba) and the frequency bandwidth (bw) of the sub-band).

According to one embodiment, the maximum energy threshold value determination module (250) may analyze energy level values of an audio signal input in real time to determine the maximum energy threshold value (E_Th) of a plurality of sub-bands (b). According to another embodiment, the maximum energy threshold value determination module (250) may determine a specified value as the maximum energy threshold value (E_Th) of a plurality of sub-bands (b) of the input audio signal.

The second quantization module (260) can quantize the maximum energy threshold value (E_Th) of each of the plurality of sub-bands (b). For example, the second quantization module (260) can quantize the first maximum energy threshold value (E_Th1) of the first sub-band (b1) to determine the first quantization threshold value, and can quantize the second maximum energy threshold value (E_Th2) of the second sub-band (b2) to determine the second quantization threshold value. The second quantization module (260) can quantize the maximum energy threshold values of the first sub-band (b1) and the second sub-band (b2) using the first bit (ba1) and the second bit (ba2), respectively.

The energy level determination module (270) can compare the quantized level value and the quantized threshold value of each of the plurality of sub-bands (b) to determine the energy level (or quantized level) of each of the plurality of sub-bands (b). For example, the energy level determination module (270) can compare the first quantized level value and the first quantized threshold value of the first sub-band (b1) to determine a smaller value as the quantized level value of the first sub-band (b1). The energy level determination module (270) can compare the second quantized level value and the second quantized threshold value of the second sub-band (b2) to determine a smaller value as the quantized level value of the second sub-band (b2).

According to one embodiment, the energy level determination module (270) may determine a range higher than the quantized level value of each of the determined plurality of sub-bands (b) as the headroom, considering a range (e.g., below the peak value) in which the second electronic device (20) can output an audio signal. For example, the energy level determination module (270) may determine a range higher than the quantized level value of the first sub-band (b1) and lower than the peak value of the second electronic device (20) as the first headroom, and may determine a range higher than the quantized level value of the second sub-band (b2) and lower than the peak value of the second electronic device (20) as the second headroom. The first headroom and the second headroom may be different from each other. Accordingly, the energy level determination module (270) may determine the headroom using the quantized threshold value of each of the plurality of sub-bands (b).

The encoding module (280) can encode a signal whose quantized level value is determined in each of a plurality of sub-bands (b) according to a compression method. Accordingly, the first electronic device (10) can transmit the encoded signal to the second electronic device (20) through the transmission module (300).

FIG. 6 is a graph showing determining energy levels for each sub-band of an electronic device according to an embodiment of the present invention.

Referring to FIG. 6, the first electronic device (10) may determine headroom using maximum energy threshold values (E_Th1 to E_Th10) in each of the plurality of sub-bands (b1 to b10). According to one embodiment, the first electronic device (10) may quantize energy level values (E1 to E10) and other maximum energy threshold values (E_Th1 to E_Th10) of the plurality of sub-bands (b1 to b10), and compare the energy level values (E1 to E10) and other maximum energy threshold values (E_Th1 to E_Th10) to determine the quantized level values of the plurality of sub-bands (b1 to b10).

For example, in the first sub-band (b1), a first energy level value (E1) (or a first quantization level value) that is lower than a first maximum energy threshold value (E-Th1) (or a first quantization threshold value) may be determined as a quantized level value of the first sub-band (b1). Accordingly, the first electronic device (10) may determine an energy range higher than the first energy level value (E1) as the first headroom.

For another example, a seventh maximum energy threshold value (E_Th7) (or seventh quantization threshold value) lower than the seventh energy level value (E7) (or seventh quantization level value) in the seventh sub-band (b7) may be determined as the quantized level value of the seventh sub-band (b7). Accordingly, the first electronic device (10) may determine an energy range higher than the quantized seventh maximum energy threshold value (E_Th7) as the seventh headroom.

According to an embodiment of the present invention, a first electronic device (10) can apply different headrooms to a plurality of sub-bands (b) by using different maximum energy threshold values (E_Th) of the plurality of sub-bands (b) according to a compression method. Accordingly, the first electronic device (10) can minimize loss of an audio signal when compressing an audio signal.

In addition, the frequency spectrum generation module (210), the psychoacoustic modeling module (220), the bit allocation module (230), the first quantization module (240), the maximum energy threshold value determination module (250), the second quantization module (260), the energy level determination module (270), and the encoding module (280) included in the encoder (200) may be implemented by the operations of the processors of FIGS. 11 and 12 described later. For example, the first electronic device (10) may include one processor that implements the operations of the modules. For another example, the first electronic device (10) may include a plurality of processors that implement the operations of the modules.

FIG. 7 is a block diagram illustrating a configuration of an electronic device that determines headroom based on the bandwidth of a sub-band and allocated bits according to one embodiment of the present invention.

Referring to FIG. 7, the encoder (700) may include a frequency spectrum generation module (710), a psychoacoustic modeling module (720), a bit allocation module (730), a maximum energy threshold value determination module (740), an energy ratio determination module (750), an energy level determination module (760), a quantization module (770), and an encoding module (780).

The frequency spectrum generation module (710), the psychoacoustic modeling module (720), and the bit allocation module (730) may operate similarly to the frequency spectrum generation module (210), the psychoacoustic modeling module (220), and the bit allocation module (230) of FIG. 5.

According to one embodiment, the maximum energy threshold value determination module (740) may determine the maximum energy threshold value (E_Th) similarly to the maximum energy threshold value determination module (250) of FIG. 5. For example, the maximum energy threshold value determination module (740) may determine the maximum energy threshold value (E_Th) using Equation 1 of the maximum energy threshold value determination module (250) of FIG. 5. As another example, the maximum energy threshold value determination module (740) may determine the maximum energy threshold value (E_Th) using a specified value.

According to another embodiment, the maximum energy threshold value determination module (740) can determine the maximum energy threshold value (E_Th) as the same value for multiple sub-bands (b).

According to one embodiment, the maximum energy threshold value determination module (740) may analyze energy level values of an audio signal input in real time to determine the maximum energy threshold value (E_Th) of a plurality of sub-bands (b). According to another embodiment, the maximum energy threshold value determination module (740) may determine a specified value as the maximum energy threshold value (E_Th) of a plurality of sub-bands (b) of the input audio signal.

The energy ratio determination module (750) can determine a ratio (h_ratio) for adjusting the energy level value (E) of each of the plurality of sub-bands (b). For example, the energy ratio determination module (750) can determine the energy ratio value using the following mathematical formula.

Here, MAX_ENERGY may be the maximum energy value that can be represented in the sub-band. The energy ratio determination module (750) may determine the first ratio (h_ratio1) of the first sub-band (b1) using, for example, the first maximum energy threshold value (E_Th1), and may determine the second ratio (h_ratio2) of the second sub-band (b2) using the second maximum energy threshold value (E_Th2). The first ratio (h_ratio1) and the second ratio (h_ration2) may be different from each other. As another example, the energy ratio determination module (750) may determine the ratio (h_ratio) by which the energy level value (E) of each of the plurality of sub-bands (b) is adjusted to a designated value (or a predetermined value). The designated value may be, for example, a ratio (h_ratio) determined based on the maximum energy threshold value (E_Th) determined by the maximum energy threshold value determination module (740). The above-mentioned specified values may be stored in the memory as a lookup table. The energy ratio determination module (750) may determine the specified value corresponding to the first maximum energy threshold value (E_Th1) as the first ratio (h_ratio1) of the first sub-band (b1), and may determine the specified value corresponding to the second maximum energy threshold value (E_Th2) as the second ratio (h_ratio2) of the second sub-band (b2).

In another embodiment, the energy ratio determination module (750) may determine the ratio (h_ratio) of the entire plurality of sub-bands (b) to be the same value. For example, the energy ratio determination module (750) may determine the ratio (h_ratio) based on the maximum energy threshold value (E_Th) determined to be the same for the entire plurality of sub-bands (b) by the maximum energy threshold value determination module (740).

According to one embodiment, the energy ratio determination module (750) can determine the ratio (h_ratio) of the plurality of sub-bands (b) in real time. For example, the energy ratio determination module (750) can determine the ratio (h_ratio) based on the maximum energy threshold value (E_Th) determined by analyzing the energy level value of the audio signal input in real time by the maximum energy threshold value determination module (740). According to another embodiment, the energy ratio determination module (750) can determine a specified value as the ratio (h_ratio) of the plurality of sub-bands (b) of the input audio signal. For example, the energy ratio determination module (750) can determine the ratio (h_ratio) based on the maximum energy threshold value (E_Th) determined as a specified value by the maximum energy threshold value determination module (740).

The energy level determination module (760) can determine the energy level value of the determined ratio of the energy level values (E) of each of the plurality of sub-bands (b) as the energy level value (or the energy level value to be quantized) of each of the plurality of sub-bands (b). For example, the energy level determination module (760) can determine the energy level value of the determined ratio of the energy level values (E) of each of the plurality of sub-bands (b) by multiplying the energy level value (E) by the ratio (h_ratio). The energy level determination module (760) can determine, for example, the energy level value of the first ratio (h_ratio1) of the first energy level value (E1) of the first sub-band (b1) as the energy level value to be quantized of the first sub-band (b1). The energy level determination module (760) can determine the energy level value of the second ratio (h_ratio2) of the second energy level value (E2) of the second sub-band (b2) as the energy level value to be quantized of the second sub-band (b2).

The energy level determination module (760) may determine a range higher than the energy level value of each of the determined plurality of sub-bands (b) as the headroom, considering a range (e.g., below the peak value) in which the second electronic device (20) can output an audio signal. For example, the energy level determination module (760) may determine a range higher than the energy level value to be quantized of the first sub-band (b1) and lower than the peak value of the second electronic device (20) as the first headroom, and may determine a range higher than the energy level value to be quantized of the second sub-band (b2) and lower than the peak value of the second electronic device (20) as the second headroom. The first headroom and the second headroom may be different from each other. Accordingly, the energy level determination module (760) may determine the headroom using the maximum energy threshold value (E_Th) of each of the plurality of sub-bands (b).

The quantization module (770) can quantize the determined energy level value (or energy level value to be quantized) of each of the plurality of sub-bands (b) into allocated bits (ba). The quantization module (770) can be similar to the first quantization module (240) of FIG. 5. For example, the quantization module (770) can quantize the determined energy level value of the first sub-band (b1) using the first bit (ba1) to determine the first quantization level value. The quantization module (770) can quantize the determined energy level value of the second sub-band (b2) using the second bit (ba2) to determine the second quantization level value.

The encoding module (780) can encode a signal whose quantized level value is determined in each of a plurality of sub-bands (b) according to a compression method. Accordingly, the first electronic device (10) can transmit the encoded signal to the second electronic device (20) through the transmission module (300).

According to an embodiment of the present invention, a first electronic device (10) can determine a ratio (h_ratio) by using different maximum energy threshold values (E_Th) of a plurality of sub-bands (b) according to a post-processing process of a second electronic device (20). In addition, different headrooms can be applied to the plurality of sub-bands (b) by using the determined ratio (h_ratio). Accordingly, the first electronic device (10) can minimize loss of an audio signal when compressing an audio signal.

FIG. 8 is a block diagram showing the configuration of an electronic device that determines headroom based on the bandwidth of a sub-band in a preprocessing process according to an embodiment of the present invention.

Referring to FIG. 8, the preprocessing module (800) may include a frequency spectrum generation module (810), a maximum energy threshold value determination module (820), an energy ratio determination module (830), and an energy level determination module (840).

According to one embodiment, a preprocessing module (800) may be additionally connected between the ADC (100) and the encoder (200). In other words, the preprocessing module (800) may be connected to the front end of the encoder (200) to process a digital signal. In other words, the preprocessing module (800) may process an audio signal before encoding. The preprocessing module (800) may apply headroom to an input audio signal and transmit it to the encoder (200).

The frequency spectrum generation module (810) can operate similarly to the frequency spectrum generation module (710) of FIG. 7.

The maximum energy threshold value determination module (820) can determine the maximum energy threshold value (E_Th) of each of the plurality of sub-bands (b) based on the frequency bandwidth (bw) of the sub-band. The maximum energy threshold value determination module (820) can determine the maximum energy threshold value (E_Th) by using the frequency bandwidth (bw) of the sub-band according to the compression method. For example, the maximum energy threshold value determination module (820) can determine the maximum energy threshold value (E_Th) by using the following mathematical equation.

Here, c1, c2, and c3 may be constants determined according to a post-processing process (e.g., equalizing, high-frequency domain restoration, etc.) of the second electronic device (20). The maximum energy threshold value determination module (820) may receive information about the post-processing process of the second electronic device (20) to determine c1, c2, and c3. The maximum energy threshold value determination module (820) may determine a first maximum energy threshold value (E_Th1) of the first sub-band (b1) using, for example, a first frequency bandwidth (bw1), and may determine a second maximum energy threshold value (E_Th2) of the second sub-band (b2) using a second frequency bandwidth (bw2) and a second bit (ba2). The first maximum energy threshold value (E_Th1) and the second maximum energy threshold value (E_Th2) may be different from each other. For another example, the maximum energy threshold value determination module (820) can determine the maximum energy threshold value (E_Th) of each of the plurality of sub-bands (b) as a designated value (or a predetermined value). For example, the maximum energy threshold value determination module (820) can be a maximum energy threshold value (E_Th) determined based on the bandwidth (bw) of the plurality of sub-bands (b). The designated value can be stored in the memory as a lookup table. The maximum energy threshold value determination module (820) can determine a designated value corresponding to the first frequency bandwidth (bw1) as the first maximum energy threshold value (E_Th1) of the first sub-band (b1), and can determine a designated value corresponding to the second frequency bandwidth (bw2) as the second maximum energy threshold value (E_Th2) of the second sub-band (b2).

In another embodiment, the maximum energy threshold value determination module (820) may determine the maximum energy threshold value (E_Th) of all of the plurality of sub-bands (b) to be the same value. The same maximum energy threshold value (E_Th) may be determined, for example, by considering the energy levels of the plurality of sub-bands (b) (e.g., based on the frequency bandwidth (bw) of the sub-band).

According to one embodiment, the maximum energy threshold value determination module (820) may analyze energy level values of an audio signal input in real time to determine the maximum energy threshold value (E_Th) of a plurality of sub-bands (b). According to another embodiment, the maximum energy threshold value determination module (820) may determine a specified value as the maximum energy threshold value (E_Th) of a plurality of sub-bands (b) of the input audio signal.

The energy ratio determination module (830) can determine a ratio (h_ratio) for adjusting the energy level value (E) of each of the plurality of sub-bands (b) similarly to the energy ratio determination module (750) of FIG. 7. For example, the energy ratio determination module (830) can determine the ratio (h_ratio) using mathematical expression 2 of the energy ratio determination module (750) of FIG. 7. As another example, the energy ratio determination module (830) can determine a ratio (h_ratio) for adjusting the energy level value (E) of each of the plurality of sub-bands (b) as a designated value (or a predetermined value).

According to another embodiment, the energy ratio determination module (830) can determine the ratio (h_ratio) of all of the multiple sub-bands (b) to be the same value.

According to one embodiment, the energy ratio determination module (830) can determine the ratio (h_ratio) of the plurality of sub-bands (b) in real time. According to another embodiment, the energy ratio determination module (830) can determine a specified value as the ratio (h_ratio) of the plurality of sub-bands (b) of the input audio signal.

The energy level determination module (840) can compare the energy level value (E) and the maximum energy threshold value (E_Th) of each of the plurality of sub-bands (b) to determine the energy level of each of the plurality of sub-bands (b). For example, the energy level determination module (840) can compare the first energy level value and the first maximum energy threshold value (E_Th1) of the first sub-band (b1) to determine the smaller value as the energy level value of the first sub-band (b1). The energy level determination module (840) can compare the second energy level value and the second maximum energy threshold value (E_Th2) of the second sub-band (b2) to determine the smaller value as the energy level value of the second sub-band (b2).

According to one embodiment, the energy level determination module (840) may determine a range higher than the energy level value of each of the determined plurality of sub-bands (b) as the headroom, considering a range (e.g., below the peak value) in which the second electronic device (20) can output an audio signal. For example, the energy level determination module (840) may determine a range higher than the energy level value of the first sub-band (b1) and lower than the peak value of the second electronic device (20) as the first headroom. The energy level determination module (840) may determine a range higher than the energy level value of the second sub-band (b2) and lower than the peak value of the second electronic device (20) as the second headroom. The first headroom and the second headroom may be different from each other. Accordingly, the energy level determination module (840) may determine the headroom using the maximum energy threshold value (E_Th) of each of the plurality of sub-bands (b).

The preprocessing module (800) can determine the headroom of each of the plurality of sub-bands (b), apply it to the plurality of sub-bands (b), and transmit the audio signal to which the headroom has been applied to the encoder (200). Accordingly, the encoder (200) may not need to separately apply the headroom during the encoding process.

According to an embodiment of the present invention, a first electronic device (10) may determine different maximum energy threshold values (E_Th) of a plurality of sub-bands (b) in consideration of a post-processing process of a second electronic device (20) in a pre-processing process, and may determine a ratio (h_ratio) using the determined maximum energy threshold values (E_th). In addition, the first electronic device (10) may apply different headrooms to the plurality of sub-bands (b) using the determined ratios (h_ratio). Accordingly, the first electronic device (10) may minimize loss of an audio signal to be encoded.

FIG. 9 is a block diagram showing the configuration of an electronic device that determines headroom based on the bandwidth of a sub-band in a post-processing process according to an embodiment of the present invention.

Referring to FIG. 9, the post-processing module (900) may include a frequency spectrum generation module (910), a maximum energy threshold value determination module (920), an energy ratio determination module (930), and an energy level determination module (940).

According to one embodiment, the post-processing module (900) may be included in the second electronic device (20). The second electronic device (20) may receive an encoded audio signal from the first electronic device (10). The audio signal received at all times is decoded by the decoder (100´), and the decoded audio signal may have headroom applied to it by the post-processing module (900). According to one embodiment, the post-processing module (900) may perform post-processing (e.g., equalizing, high-frequency domain restoration, etc.) on the audio signal to which the headroom is applied. Accordingly, the audio signal to which the headroom is applied may be post-processed and transmitted to the ADC (300´), and may be converted into an analog signal by the ADC (300´) and output to the outside.

The frequency spectrum generation module (910) may be similar to the frequency spectrum generation module (810) of FIG. 8.

The maximum energy threshold value determination module (920) can determine the maximum energy threshold value (E_Th) of each of the plurality of sub-bands (b) based on the frequency bandwidth (bw) of the sub-band. The maximum energy threshold value determination module (920) can determine the maximum energy threshold value (E_Th) by using the frequency bandwidth (bw) of the sub-band according to the compression method. For example, the maximum energy threshold value determination module (920) can determine the maximum energy threshold value (E_Th) by using the following mathematical equation.

Here, c1, c2, and c3 may be constants determined according to a post-processing process (e.g., equalizing, high-frequency domain restoration, etc.). The maximum energy threshold value determination module (920) may determine a first maximum energy threshold value (E_Th1) of the first sub-band (b1) using, for example, a first frequency bandwidth (bw1), and may determine a second maximum energy threshold value (E_Th2) of the second sub-band (b2) using a second frequency bandwidth (bw2) and a second bit (ba2). The first maximum energy threshold value (E_Th1) and the second maximum energy threshold value (E_Th2) may be different from each other. As another example, the maximum energy threshold value determination module (920) may determine the maximum energy threshold value (E_Th) of each of the plurality of sub-bands (b) as a specified value (or a predetermined value).

In another embodiment, the maximum energy threshold value determination module (920) may determine the maximum energy threshold value (E_Th) of all the plurality of sub-bands (b) to be the same value. The same maximum energy threshold value (E_Th) may be determined, for example, by considering the energy levels of the plurality of sub-bands (b) (e.g., based on the frequency bandwidth (bw) of the sub-band).

According to one embodiment, the maximum energy threshold value determination module (920) may analyze energy level values of an audio signal input in real time to determine the maximum energy threshold value (E_Th) of a plurality of sub-bands (b). According to another embodiment, the maximum energy threshold value determination module (920) may determine a specified value as the maximum energy threshold value (E_Th) of a plurality of sub-bands (b) of the input audio signal.

The energy ratio determination module (930) can determine a ratio (h_ratio) to adjust the energy level value (E) of each of the plurality of sub-bands (b). The energy ratio determination module (930) can be similar to the energy ratio determination module (830) of FIG. 8. For example, the energy ratio determination module (930) can determine the energy ratio value using the following mathematical formula, which is the same as the energy ratio determination module (830) of FIG. 8.

Here, MAX_ENERGY may be the maximum energy value that can be included in the sub-band. The energy ratio determination module (930) may determine the first ratio (h_ratio1) of the first sub-band (b1) using, for example, the first maximum energy threshold value (E_Th1), and may determine the second ratio (h_ratio2) of the second sub-band (b2) using the second maximum energy threshold value (E_Th2).

The energy level determination module (940) can determine the energy level value of the determined ratio of the energy level values (E) of each of the plurality of sub-bands (b) as the energy level value of each of the plurality of sub-bands (b). For example, the energy level determination module (940) can determine the energy level value of the determined ratio of the energy level values (E) of each of the plurality of sub-bands (b) by multiplying the energy level value (E) by the ratio (h_ratio). The energy level determination module (940) can determine, for example, the energy level value of the first ratio (h_ratio1) of the first energy level value (E1) of the first sub-band (b1) as the energy level value of the first sub-band (b1). The energy level determination module (940) can determine the energy level value of the second ratio (h_ratio2) of the second energy level value (E2) of the second sub-band (b) as the energy level value of the second sub-band (b2).

According to one embodiment, the energy level determination module (940) may determine a range higher than the energy level value of each of the determined plurality of sub-bands (b) as the headroom, considering a range (e.g., below the peak value) in which the second electronic device (20) can output an audio signal. For example, the energy level determination module (940) may determine a range higher than the energy level value of the first sub-band (b1) and lower than the peak value of the second electronic device (20) as the first headroom. The energy level determination module (940) may determine a range higher than the energy level value of the second sub-band (b2) and lower than the peak value of the second electronic device (20) as the second headroom. The first headroom and the second headroom may be different from each other. Accordingly, the energy level determination module (940) may determine the headroom using the maximum energy threshold value (E_Th) of each of the plurality of sub-bands (b).

The post-processing module (900) may receive the decoded audio signal from the decoder (100´), determine the headroom of each of the plurality of sub-bands (b), apply the headroom to the plurality of sub-bands (b), and post-process the audio signal to which the headroom has been applied. The post-processing module (900) may post-process the audio signal to which the headroom has been applied and transmit the result to the ADC (200´). Accordingly, there may be no need to apply the headroom in the first electronic device (10).

The second electronic device (20) according to an embodiment of the present invention can determine a ratio (h_ratio) by using different maximum energy threshold values (E_Th) of a plurality of sub-bands (b) in a post-processing process. In addition, the second electronic device (20) can apply different headrooms to the plurality of sub-bands (b) by using the determined ratio (h_ratio) and post-process an audio signal to which the headroom is applied. Accordingly, the second electronic device (10) can minimize loss of a decoded audio signal when applying the headroom.

According to one embodiment, the second electronic device (20) can apply headroom in the decoder (100´). The audio signal processing process of the second electronic device (20) can be the reverse of the audio signal processing process of the first electronic device (10). For example, the second electronic device (20) can decode the received audio signal and dequantize the decoded audio signal. Accordingly, the second electronic device (20) can adjust the energy level value for each of a plurality of sub-bands of the audio signal by applying the method described in FIGS. 5 to 7 in reverse during the process of dequantizing the audio signal.

According to various embodiments of the present invention described with reference to FIGS. 1 to 9, a first electronic device (10) and a second electronic device (20) separate a frequency band for an audio signal into a plurality of sub-bands (b), analyze an energy level value (E) of each of the separated sub-bands (b) to determine a maximum energy threshold value (E_Th), and apply different headrooms to the plurality of frequency bands (b) using the maximum energy threshold value (E_Th), thereby preventing clipping that occurs when outputting an audio signal and minimizing loss that may occur when compressing an audio signal, thereby allowing the second electronic device to output a high-quality audio signal.

In addition, the function of setting the headroom differently for each of the multiple sub-bands (b) of the first electronic device (10) and the second electronic device (20) is implemented by a simple algorithm of comparing energy level values or multiplying ratios, enabling fast processing and can be easily applied to small electronic devices (e.g., hearing aids).

FIG. 10 is a flowchart illustrating a method for controlling an electronic device for encoding an audio signal according to an embodiment of the present invention.

The flow chart illustrated in FIG. 10 may be composed of operations processed in the first electronic device (10) described above, and represents a control method of the electronic device (10) for applying different headrooms to each of a plurality of sub-bands (b). Accordingly, even if the content is omitted below, the content described with respect to the first electronic device (200) with reference to FIGS. 1 to 9 may be applied to the flow chart illustrated in FIG. 10.

In one embodiment, in operation 1010, the first electronic device (10) can divide a frequency band corresponding to an audio signal into a plurality of sub-bands (b).

In one embodiment, in operation 1020, the first electronic device (10) may allocate bits (ba) to quantize an energy level value of each of the plurality of sub-bands (b). For example, the first electronic device (10) may allocate more bits (ba) to a sub-band included in a major frequency band among the plurality of sub-bands (b) than to a sub-band not included in the major frequency band. The major frequency may be, for example, a frequency band having high sensitivity and containing a lot of information within a human audible frequency band analyzed by a psychoacoustic model.

In one embodiment, in operation 1030, the first electronic device (10) can determine the headroom of the sub-band (s) based on the bandwidth (bw) of the sub-band and the allocated bits (ba). For example, the first electronic device (10) can determine the maximum energy threshold value (E_Th) by using the bandwidth (bw) of the sub-band and the allocated bits (ba). The first electronic device (10) can determine different headrooms of the plurality of sub-bands by using the determined maximum energy threshold value (E_Th).

In one embodiment, in operation 1040, the first electronic device (10) can apply the determined headroom to a plurality of sub-bands (b). The first electronic device (10) can encode an audio signal to which the different headrooms are applied to each of the plurality of sub-bands (b) and transmit the encoded audio signal to the second electronic device (20).

FIG. 11 illustrates electronic devices within a network environment according to various embodiments.

Referring to FIG. 11, in various embodiments, an electronic device (1601), a first electronic device (1602), a second electronic device (1604), or a server (1606) may be connected to each other via a network (1662) or short-range communication (1664). The electronic device (1601) may include a bus (1610), a processor (1620), a memory (1630), an input/output interface (1650), a display (1660), and a communication interface (1670). In some embodiments, the electronic device (1601) may omit at least one of the components or additionally include another component.

The bus (1610) may include circuitry for, for example, connecting the components (1620-1670) to each other and transmitting communications (e.g., control messages and/or data) between the components.

The processor (1620) may include one or more of a Central Processing Unit (CPU), an Application Processor (AP), or a Communication Processor (CP). The processor (1620) may, for example, perform calculations or data processing related to control and/or communication of at least one other component of the electronic device (1601).

The memory (1630) may include volatile and/or non-volatile memory. The memory (1630) may store, for example, instructions or data related to at least one other component of the electronic device (1601). According to one embodiment, the memory (1630) may store software and/or programs (1640). The programs (1620) may include, for example, a kernel (1641), middleware (1643), an Application Programming Interface (API) (1645), and/or an application program (or “application”) (1647). At least a portion of the kernel (1641), the middleware (1643), or the API (1645) may be referred to as an Operating System (OS).

The kernel (1641) may control or manage system resources (e.g., a bus (1610), a processor (1620), or a memory (1630)) used to execute operations or functions implemented in other programs (e.g., a middleware (1643), an API (1645), or an application program (1647)). In addition, the kernel (1641) may provide an interface that allows the middleware (1643), the API (1645), or the application program (1647) to control or manage system resources by accessing individual components of the electronic device (1601).

Middleware (1643) may act as an intermediary to allow, for example, an API (1645) or an application program (1647) to communicate with the kernel (1641) and exchange data.

In addition, the middleware (1643) can process one or more work requests received from the application program (1647) according to priorities. For example, the middleware (1643) can assign a priority to at least one of the application programs (1647) to use system resources (e.g., bus (1610), processor (1620), memory (1630), etc.) of the electronic device (1601). For example, the middleware (1643) can perform scheduling or load balancing, etc. for the one or more work requests by processing the one or more work requests according to the priority assigned to the at least one of the work requests.

API (1645) is, for example, an interface for an application (1647) to control functions provided by the kernel (1641) or middleware (1643), and may include at least one interface or function (e.g., command) for, for example, file control, window control, image processing, or character control.

The input/output interface (1650) may serve as an interface that can transmit, for example, a command or data input from a user or another external device to other component(s) of the electronic device (1601). In addition, the input/output interface (1650) may output a command or data received from other component(s) of the electronic device (1601) to the user or another external device.

The display (1660) may include, for example, a Liquid Crystal Display (LCD), a Light-Emitting Diode (LED) display, an Organic LED (OLED) display, a microelectromechanical systems (MEMS) display, or an electronic paper display. The display (1660) may display, for example, various contents (e.g., text, images, videos, icons, or symbols) to a user. The display (1660) may include a touch screen and may receive touch, gesture, proximity, or hovering inputs, for example, using an electronic pen or a part of the user's body.

The communication interface (1670) can establish communication between, for example, the electronic device (1601) and an external device (e.g., the first electronic device (1602), the second electronic device (1604), or the server (1606)). For example, the communication interface (1670) can be connected to a network (1662) via wireless communication or wired communication to communicate with the external device (e.g., the second electronic device (1604) or the server (1606)).

The wireless communication may use, for example, at least one of a cellular communication protocol, such as LTE (Long-Term Evolution), LTE-A (LTE-Advanced), CDMA (Code Division Multiple Access), WCDMA (Wideband CDMA), UMTS (Universal Mobile Telecommunications System), WiBro (Wireless Broadband), or GSM (Global System for Mobile Communications). In addition, the wireless communication may include, for example, short-range communication (1664). The short-range communication (1664) may include, for example, at least one of Wi-Fi (Wireless Fidelity), Bluetooth, NFC (Near Field Communication), MST (magnetic stripe transmission), or GNSS.

MST generates a pulse according to transmission data using an electromagnetic signal, and the pulse can generate a magnetic field signal. An electronic device (1601) transmits the magnetic field signal to a point of sales (POS), and the POS detects the magnetic field signal using an MST reader, and can restore the data by converting the detected magnetic field signal into an electrical signal.

GNSS may include at least one of, for example, GPS (Global Positioning System), Glonass (Global Navigation Satellite System), Beidou Navigation Satellite System (hereinafter "Beidou"), or Galileo (the European global satellite-based navigation system), depending on the usage area or bandwidth. Hereinafter, in this document, "GPS" may be used interchangeably with "GNSS". The wired communication may include at least one of, for example, USB (universal serial bus), HDMI (high definition multimedia interface), RS-232 (recommended standard-232), or POTS (plain old telephone service). The network (1662) may include at least one of a telecommunications network, for example, a computer network (e.g., LAN or WAN), the Internet, or a telephone network.

Each of the first electronic device (1602) and the second electronic device (1604) may be the same type of device as or different from the electronic device (1601). According to one embodiment, the server (1606) may include a group of one or more servers. According to various embodiments, all or part of the operations executed in the electronic device (1601) may be executed in another one or more electronic devices (e.g., the first electronic device (1602), the second electronic device (1604), or the server (1606)). According to one embodiment, when the electronic device (1601) is to perform a certain function or service automatically or upon request, the electronic device (1601) may request at least some functions associated therewith from another electronic device (e.g., the first electronic device (1602), the second electronic device (1604), or the server (1606)) instead of executing the function or service by itself or in addition. Another electronic device may execute the requested function or additional function and transmit the result to the electronic device (1601). The electronic device (1601) may process the received result as is or additionally to provide the requested function or service. For this purpose, for example, cloud computing, distributed computing, or client-server computing technology may be used.

FIG. 12 shows a block diagram of an electronic device according to an embodiment of the present invention.

Referring to FIG. 12, the electronic device (1701) may include, for example, all or part of the electronic device (1601) illustrated in FIG. 16. The electronic device (1701) may include one or more processors (e.g., AP) (1710), a communication module (1720), a subscriber identification module (1724), a memory (1730), a sensor module (1740), an input device (1750), a display (1760), an interface (1770), an audio module (1780), a camera module (1791), a power management module (1795), a battery (1796), an indicator (1797), and a motor (1798).

The processor (1710) may control a plurality of hardware or software components connected to the processor (1710) by, for example, driving an operating system or an application program, and may perform various data processing and calculations. The processor (1710) may be implemented as, for example, a system on chip (SoC). According to one embodiment, the processor (1710) may further include a GPU (graphic processing unit) and/or an image signal processor. The processor (1710) may also include at least some of the components illustrated in FIG. 17 (e.g., a cellular module (1721)). The processor (1710) may load and process commands or data received from at least one of the other components (e.g., a nonvolatile memory) into the volatile memory, and store various data in the nonvolatile memory.

The communication module (1720) may have the same or similar configuration as the communication interface (1670) of FIG. 16. The communication module (1720) may include, for example, a cellular module (1721), a Wi-Fi module (1723), a Bluetooth module (1725), a GNSS module (1727) (e.g., a GPS module, a Glonass module, a Beidou module, or a Galileo module), an NFC module (1728), and an RF (radio frequency) module (1729).

The cellular module (1721) may provide, for example, voice calls, video calls, text services, or Internet services through a communication network. According to one embodiment, the cellular module (1721) may perform differentiation and authentication of the electronic device (1701) within the communication network using a subscriber identification module (e.g., SIM card) (1724). According to one embodiment, the cellular module (1721) may perform at least some of the functions that the processor (1710) may provide. According to one embodiment, the cellular module (1721) may include a communication processor (CP).

Each of the Wi-Fi module (1723), the Bluetooth module (1725), the GNSS module (1727), or the NFC module (1728) may include, for example, a processor for processing data transmitted and received through the corresponding module. According to some embodiments, at least some (e.g., two or more) of the cellular module (1721), the Wi-Fi module (1723), the Bluetooth module (1725), the GNSS module (1727), or the NFC module (1728) may be included in a single integrated chip (IC) or IC package.

The RF module (1729) may, for example, transmit and receive communication signals (e.g., RF signals). The RF module (1729) may include, for example, a transceiver, a power amp module (PAM), a frequency filter, a low noise amplifier (LNA), or an antenna. According to another embodiment, at least one of the cellular module (1721), the Wi-Fi module (1723), the Bluetooth module (1725), the GNSS module (1727), and the NFC module (1728) may transmit and receive RF signals through a separate RF module.

The subscriber identity module (1724) may include, for example, a card including a subscriber identity module and/or an embedded SIM, and may include unique identification information (e.g., an integrated circuit card identifier (ICCID)) or subscriber information (e.g., an international mobile subscriber identity (IMSI)).

The memory (1730) (e.g., the memory (1630)) may include, for example, built-in memory (1732) or external memory (1734). The built-in memory (1732) may include, for example, at least one of a volatile memory (e.g., dynamic RAM (DRAM), static RAM (SRAM), or synchronous dynamic RAM (SDRAM)), a non-volatile memory (e.g., one time programmable ROM (OTPROM), a programmable ROM (PROM), an erasable and programmable ROM (EPROM), an electrically erasable and programmable ROM (EEPROM), a mask ROM, a flash ROM, a flash memory (e.g., NAND flash or NOR flash), a hard drive, or a solid state drive (SSD).

The external memory (1734) may further include a flash drive, for example, a compact flash (CF), a secure digital (SD), a Micro-SD, a Mini-SD, an extreme digital (xD), a MultiMediaCard (MMC), or a memory stick. The external memory (1734) may be functionally and/or physically connected to the electronic device (1701) via various interfaces.

The sensor module (1740) may, for example, measure a physical quantity or detect an operating state of an electronic device (1701) and convert the measured or detected information into an electrical signal. The sensor module (1740) may include, for example, at least one of a gesture sensor (1740A), a gyro sensor (1740B), a pressure sensor (1740C), a magnetic sensor (1740D), an acceleration sensor (1740E), a grip sensor (1740F), a proximity sensor (1740G), a color sensor (1740H) (e.g., an RGB sensor), a biometric sensor (1740I), a temperature/humidity sensor (1740J), an illuminance sensor (1740K), or a UV (ultra violet) sensor (1740M). Additionally or alternatively, the sensor module (1740) may include, for example, an E-nose sensor, an EMG (electromyography) sensor, an EEG (electroencephalogram) sensor, an ECG (electrocardiogram) sensor, an IR (infrared) sensor, an iris sensor, and/or a fingerprint sensor. The sensor module (1740) may further include a control circuit for controlling at least one or more sensors included therein. In some embodiments, the electronic device (1701) further includes a processor configured to control the sensor module (1740), either as part of or separately from the processor (1710), such that the sensor module (1740) can be controlled while the processor (1710) is in a sleep state.

The input device (1750) may include, for example, a touch panel (1752), a (digital) pen sensor (1754), a key (1756), or an ultrasonic input device (1758). The touch panel (1752) may use, for example, at least one of a capacitive method, a pressure-sensitive method, an infrared method, or an ultrasonic method. In addition, the touch panel (1752) may further include a control circuit. The touch panel (1752) may further include a tactile layer to provide a tactile response to a user.

The (digital) pen sensor (1754) may be, for example, part of a touch panel or may include a separate recognition sheet. The key (1756) may include, for example, a physical button, an optical key, or a keypad. The ultrasonic input device (1758) may detect ultrasonic waves generated from an input tool through a microphone (e.g., microphone (1788)) and determine data corresponding to the detected ultrasonic waves.

The display (1760) (e.g., the display (1660)) may include a panel (1762), a holographic device (1764), or a projector (1766). The panel (1762) may include a configuration identical to or similar to the display (1660) of FIG. 16. The panel (1762) may be implemented to be, for example, flexible, transparent, or wearable. The panel (1762) may also be configured as a single module with the touch panel (1752). The holographic device (1764) may use interference of light to display a three-dimensional image in the air. The projector (1766) may project light onto a screen to display an image. The screen may be located, for example, inside or outside the electronic device (1701). According to one embodiment, the display (1760) may further include control circuitry for controlling the panel (1762), the holographic device (1764), or the projector (1766).

The interface (1770) may include, for example, HDMI (1772), USB (1774), an optical interface (1776), or D-sub (D-subminiature) (1778). The interface (1770) may be included, for example, in the communication interface (1670) illustrated in FIG. 16. Additionally or alternatively, the interface (1770) may include, for example, a mobile high-definition link (MHL) interface, an SD card/MMC interface, or an infrared data association (IrDA) standard interface.

The audio module (1780) can, for example, bidirectionally convert sound and electrical signals. At least some components of the audio module (1780) can be included in, for example, the input/output interface (1650) illustrated in FIG. 16. The audio module (1780) can process sound information input or output through, for example, a speaker (1782), a receiver (1784), an earphone (1786), or a microphone (1788).

A camera module (1791) is, for example, a device capable of capturing still images and moving images, and according to one embodiment, may include one or more image sensors (e.g., a front sensor or a rear sensor), a lens, an image signal processor (ISP), or a flash (e.g., an LED or a xenon lamp).

The power management module (1795) can manage power of the electronic device (1701), for example. According to one embodiment, the power management module (1795) can include a power management integrated circuit (PMIC), a charger integrated circuit (IC), or a battery or fuel gauge. The PMIC can have a wired and/or wireless charging method. The wireless charging method includes, for example, a magnetic resonance method, a magnetic induction method, or an electromagnetic wave method, and can further include an additional circuit for wireless charging, for example, a coil loop, a resonant circuit, or a rectifier. The battery gauge can measure, for example, the remaining capacity of the battery (1796), voltage, current, or temperature during charging. The battery (1796) can include, for example, a rechargeable battery and/or a solar battery.

The indicator (1797) can indicate a specific state of the electronic device (1701) or a part thereof (e.g., the processor (1710)), such as a booting state, a message state, or a charging state. The motor (1798) can convert an electrical signal into a mechanical vibration and can generate vibration, a haptic effect, or the like. Although not shown, the electronic device (1701) can include a processing unit (e.g., a GPU) for supporting mobile TV. The processing unit for supporting mobile TV can process media data according to a standard such as, for example, DMB (Digital Multimedia Broadcasting), DVB (Digital Video Broadcasting), or MediaFLO ^TM .

Each of the components described in this document may be composed of one or more parts (components), and the names of the corresponding components may vary depending on the type of the electronic device. In various embodiments, the electronic device may be composed of at least one of the components described in this document, and some of the components may be omitted or may further include other additional components. In addition, some of the components of the electronic device according to various embodiments may be combined to form a single entity, thereby performing the same functions of the corresponding components prior to being combined.

Claims (20)

In electronic devices,
A memory for storing audio signal data; and
Contains a processor,
The above processor,
Divide the frequency band corresponding to the above audio signal into multiple sub-bands,
In order to quantize a first subband among the plurality of subbands, a first bit is allocated to the first subband,
Determine the first headroom of the first sub-band based on the bandwidth of the first sub-band and the allocated first bit,
The audio signal is set to be processed by applying the determined first headroom to the first sub-band among the plurality of sub-bands and applying a second headroom having a different value from the first headroom to at least some of the remaining sub-bands.
Determine a first energy level value and a first maximum energy threshold value of the first sub-band based on the bandwidth of the first sub-band and the allocated first bit,
An electronic device configured to determine the first headroom of the first sub-band based on a lower value of the first energy level value and the first maximum energy threshold value. delete delete delete In claim 1,
The above processor,
Determine the ratio of the first maximum energy threshold to the maximum energy value of the first sub-band,
An electronic device configured to determine a first headroom of the first sub-band by determining an energy level value of the determined ratio of the first energy level value of the first sub-band as the first energy level value of the first sub-band. In claim 1,
The above processor,
Each of the above multiple sub-bands to which headroom is applied is quantized,
An electronic device, wherein each of the plurality of sub-bands is set to process a quantized audio signal. In claim 1,
The above processor,
To quantize a second sub-band among the plurality of sub-bands, a second bit less than the first bit is allocated,
An electronic device configured to determine a second maximum energy threshold value that is less than the first maximum energy threshold value based on the bandwidth of the second sub-band and the allocated second bit. In claim 1,
The above processor,
An electronic device configured to determine the first maximum energy threshold of the first sub-band according to a method of encoding the audio signal using the bandwidth of the first sub-band and the allocated first bit. In claim 1,
The above memory is,
Store the maximum energy threshold value determined based on the bandwidth of the plurality of sub-bands and the bits allocated to the plurality of sub-bands,
The above processor,
An electronic device, wherein when determining the first maximum energy threshold value of the first sub-band, a value corresponding to the bandwidth of the first sub-band and the allocated first bit among the maximum energy threshold values stored in the memory is determined as the first maximum energy threshold value of the first sub-band. In a method for controlling an electronic device,
An operation of dividing a frequency band corresponding to an audio signal into multiple sub-bands;
An operation of allocating a first bit to a first subband to quantize the first subband among the plurality of subbands;
An operation of determining a first headroom of the first sub-band based on the bandwidth of the first sub-band and the allocated first bit;
An operation for processing the audio signal by applying the determined first headroom to the first sub-band among the plurality of sub-bands and applying a second headroom having a different value from the first headroom to at least some of the remaining sub-bands;
An operation of determining a first energy level value and a first maximum energy threshold value of the first sub-band based on the bandwidth of the first sub-band and the allocated first bit; and
A method comprising: determining the first headroom of the first sub-band based on a lower value of the first energy level value and the first maximum energy threshold value. delete delete delete In claim 10,
An operation for determining the first headroom of the first sub-band;
An operation for determining a ratio of the first maximum energy threshold value to the maximum energy value of the first sub-band; and
A method comprising: determining a first headroom of the first sub-band by determining an energy level value of the determined ratio of the first energy level value as the first energy level value of the first sub-band. In claim 10,
An operation of processing the audio signal by applying headroom to the plurality of sub-bands;
An operation of quantizing each of the plurality of sub-bands to which the headroom is applied; and
A method comprising: processing an audio signal in which the level values of each of the plurality of sub-bands are quantized. In electronic devices,
A memory for storing audio signal data; and
Contains a processor,
The above processor,
Divide the frequency band corresponding to the above audio signal into multiple sub-bands,
Determine the first headroom of the first sub-band based on the bandwidth of the first sub-band among the above multiple sub-bands,
The audio signal is set to be processed by applying the determined first headroom to the first sub-band among the plurality of sub-bands and applying a second headroom having a different value from the first headroom to at least some of the remaining sub-bands.
Determine a first energy level value and a first maximum energy threshold value of the first sub-band based on the bandwidth of the first sub-band,
An electronic device configured to determine the first headroom of the first sub-band based on a lower value of the first energy level value and the first maximum energy threshold value. delete ◈Claim 18 was abandoned upon payment of the registration fee.◈ In claim 16,
The above processor,
Determine the ratio of the first maximum energy threshold to the maximum energy value of the first sub-band,
An electronic device configured to determine a first headroom of the first sub-band by determining an energy level value of the determined ratio of the first energy level value of the first sub-band as the first energy level value of the first sub-band. ◈Claim 19 was abandoned upon payment of the registration fee.◈ In claim 16,
The above processor,
An electronic device configured to determine the first maximum energy threshold of the first sub-band according to a processing method for outputting an encoded audio signal using the bandwidth of the first sub-band. ◈Claim 20 was abandoned upon payment of the registration fee.◈ In claim 16,
The above memory is,
Store the maximum energy threshold value determined based on the bandwidth of the above multiple sub-bands,
The above processor,
An electronic device, wherein when determining the first maximum energy threshold value of the first sub-band, a value corresponding to the bandwidth of the first sub-band among the maximum energy threshold values stored in the memory is determined as the first maximum energy threshold value of the first sub-band.

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