CN111565346B

CN111565346B - Method and device for determining parameters of line speaker array, storage medium and terminal

Info

Publication number: CN111565346B
Application number: CN202010405785.6A
Authority: CN
Inventors: 蒋燚
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2020-05-14
Filing date: 2020-05-14
Publication date: 2021-09-17
Anticipated expiration: 2040-05-14
Also published as: CN111565346A

Abstract

The embodiment of the application discloses a method, a device, a storage medium and a terminal for determining parameters of a line loudspeaker array, wherein the method comprises the following steps: acquiring an initial audio signal, and performing down-sampling processing on the initial audio signal to obtain a down-sampled audio signal; acquiring the wavelength range of the down-sampling audio signal, and determining the array element spacing of the line loudspeaker array based on the wavelength range of the down-sampling audio signal; carrying out low-frequency filtering processing on the down-sampling audio signal to obtain a filtered audio signal; and acquiring the wavelength range of the filtering audio signal, and determining the length of the line sound source of the line loudspeaker array based on the wavelength range of the filtering audio signal. By adopting the embodiment of the application, the balance between the size of the line loudspeaker array and the directivity can be met, and the line loudspeaker array is suitable for a micro line loudspeaker array.

Description

Method and device for determining parameters of line speaker array, storage medium and terminal

Technical Field

The present application relates to the field of computer technologies, and in particular, to a method and an apparatus for determining parameters of a line speaker array, a storage medium, and a terminal.

Background

The directivity of a line speaker array is too dependent on the signal frequency, and the directivity is relatively easy to keep constant for a narrow-band signal. However, the audio signal is a broadband signal, and the directivity of the line speaker array is good for the high frequency part, but the comb filtering effect is easily generated; for the low frequency part, when the length of the line sound source of the line loudspeaker array is smaller than the half wavelength of the maximum wavelength of the audio signal, the range of the main lobe of the loudspeaker line array is large, and the directivity is poor. Therefore, in order to ensure good directivity, it is necessary to ensure that the line source length is longer than a half wavelength of the maximum wavelength. In general, the directivity can be improved by increasing the array area and the number of array elements, but the loudspeaker is not portable due to the increase of the volume.

Disclosure of Invention

The embodiment of the application provides a method and a device for determining parameters of a line speaker array, a storage medium and a terminal, which can meet the balance between the size and the directivity of the line speaker array and are suitable for a micro line speaker array. The technical scheme is as follows:

in a first aspect, an embodiment of the present application provides a method for determining parameters of a line speaker array, where the method includes:

acquiring an initial audio signal, and performing down-sampling processing on the initial audio signal to obtain a down-sampled audio signal;

acquiring the wavelength range of the down-sampling audio signal, and determining the array element spacing of the line loudspeaker array based on the wavelength range of the down-sampling audio signal;

carrying out low-frequency filtering processing on the down-sampling audio signal to obtain a filtered audio signal;

and acquiring the wavelength range of the filtering audio signal, and determining the length of the line sound source of the line loudspeaker array based on the wavelength range of the filtering audio signal.

In a second aspect, an embodiment of the present application provides an apparatus for determining parameters of a line speaker array, where the apparatus includes:

the down-sampling processing module is used for acquiring an initial audio signal and performing down-sampling processing on the initial audio signal to obtain a down-sampled audio signal;

the array element spacing determining module is used for acquiring the wavelength range of the down-sampling audio signal and determining the array element spacing of the line loudspeaker array based on the wavelength range of the down-sampling audio signal;

the low-frequency filtering module is used for carrying out low-frequency filtering processing on the downsampled audio signal to obtain a filtered audio signal;

and the line sound source length determining module is used for acquiring the wavelength range of the filtering audio signal and determining the line sound source length of the line loudspeaker array based on the wavelength range of the filtering audio signal.

In a third aspect, embodiments of the present application provide a computer storage medium storing a plurality of instructions adapted to be loaded by a processor and to perform the above-mentioned method steps.

In a fourth aspect, an embodiment of the present application provides a terminal, which may include: a processor and a memory; wherein the memory stores a computer program adapted to be loaded by the processor and to perform the above-mentioned method steps.

The beneficial effects brought by the technical scheme provided by some embodiments of the application at least comprise:

in this application embodiment, through obtaining initial audio signal, it is right initial audio signal carries out down sampling processing, obtains down sampling audio signal, and obtains down sampling audio signal's wavelength range, based on down sampling audio signal's wavelength range determination line speaker array's array element interval can avoid high frequency signal to produce the comb filtering effect when passing through the line speaker array when guaranteeing that the array element interval is little suitable for little line speaker array, again right down sampling audio signal carries out low frequency filter and handles, obtains filtering audio signal's wavelength range, based on filtering audio signal's wavelength range is confirmed line speaker array's line sound source length has reduced the main lobe width, can improve low frequency signal's directive property. The balance between the size of the line loudspeaker array and the directivity can be satisfied, and the line loudspeaker array is suitable for a micro line loudspeaker array. The size is small and exquisite, and the portability is strong, does benefit to extensive popularization.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a terminal provided in an embodiment of the present application;

FIG. 2 is a schematic structural diagram of an operating system and a user space provided in an embodiment of the present application;

FIG. 3 is an architectural diagram of the android operating system of FIG. 1;

FIG. 4 is an architecture diagram of the IOS operating system of FIG. 1;

fig. 5(a) to (c) are schematic diagrams illustrating examples of a point sound source, a line sound source, and a plane sound source according to an embodiment of the present application;

fig. 6 is a schematic flowchart of a method for determining parameters of a line speaker array according to an embodiment of the present application;

fig. 7 is an exemplary schematic diagram of down-sampling of an audio signal provided by an embodiment of the present application;

fig. 8 is a schematic flowchart of another method for determining parameters of a line speaker array according to an embodiment of the present application;

FIG. 9 is a schematic diagram illustrating an example of a high pass filter provided in an embodiment of the present application;

fig. 10 is a schematic flowchart of another method for determining parameters of a line speaker array according to an embodiment of the present application;

fig. 11 is a schematic structural diagram of a parameter determining apparatus of a line speaker array according to an embodiment of the present application;

fig. 12 is a schematic structural diagram of a parameter determining apparatus for a line speaker array according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In the description of the present application, it is to be understood that the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. In the description of the present application, it is noted that, unless explicitly stated or limited otherwise, "including" and "having" and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements listed, but may alternatively include other steps or elements not listed, or inherent to such process, method, article, or apparatus. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art. Further, in the description of the present application, "a plurality" means two or more unless otherwise specified. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.

Referring to fig. 1, a block diagram of a terminal according to an exemplary embodiment of the present application is shown. A terminal in the present application may include one or more of the following components: a processor 110, a memory 120, an input device 130, an output device 140, and a bus 150. The processor 110, memory 120, input device 130, and output device 140 may be connected by a bus 150.

Processor 110 may include one or more processing cores. The processor 110 connects various parts within the entire terminal using various interfaces and lines, and performs various functions of the terminal 100 and processes data by executing or executing instructions, programs, code sets, or instruction sets stored in the memory 120 and calling data stored in the memory 120. Alternatively, the processor 110 may be implemented in hardware using at least one of Digital Signal Processing (DSP), field-programmable gate Array (FPGA), and Programmable Logic Array (PLA). The processor 110 may integrate one or more of a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), a modem, and the like. The CPU mainly processes an operating system, a user page, an application program and the like; the GPU is used for rendering and drawing display content; the modem is used to handle wireless communications. It is understood that the modem may not be integrated into the processor 110, but may be implemented by a communication chip.

The Memory 120 may include a Random Access Memory (RAM) or a read-only Memory (ROM). Optionally, the memory 120 includes a non-transitory computer-readable medium. The memory 120 may be used to store instructions, programs, code sets, or instruction sets. The memory 120 may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for implementing at least one function (such as a touch function, a sound playing function, an image playing function, etc.), instructions for implementing various method embodiments described below, and the like, and the operating system may be an Android (Android) system, including a system based on Android system depth development, an IOS system developed by apple, including a system based on IOS system depth development, or other systems. The storage data area may also store data created by the terminal in use, such as a phonebook, audio-video data, chat log data, etc.

Referring to fig. 2, the memory 120 may be divided into an operating system space, in which an operating system runs, and a user space, in which native and third-party applications run. In order to ensure that different third-party application programs can achieve a better operation effect, the operating system allocates corresponding system resources for the different third-party application programs. However, the requirements of different application scenarios in the same third-party application program on system resources are different, for example, in a local resource loading scenario, the third-party application program has a higher requirement on the disk reading speed; in the animation rendering scene, the third-party application program has a high requirement on the performance of the GPU. The operating system and the third-party application program are independent from each other, and the operating system cannot sense the current application scene of the third-party application program in time, so that the operating system cannot perform targeted system resource adaptation according to the specific application scene of the third-party application program.

In order to enable the operating system to distinguish a specific application scenario of the third-party application program, data communication between the third-party application program and the operating system needs to be opened, so that the operating system can acquire current scenario information of the third-party application program at any time, and further perform targeted system resource adaptation based on the current scenario.

Taking an operating system as an Android system as an example, programs and data stored in the memory 120 are as shown in fig. 3, and a Linux kernel layer 320, a system runtime library layer 340, an application framework layer 360, and an application layer 380 may be stored in the memory 120, where the Linux kernel layer 320, the system runtime library layer 340, and the application framework layer 360 belong to an operating system space, and the application layer 380 belongs to a user space. The Linux kernel layer 320 provides underlying drivers for various hardware of the terminal, such as a display driver, an audio driver, a camera driver, a bluetooth driver, a Wi-Fi driver, a power management, and the like. The system runtime library layer 340 provides a main feature support for the Android system through some C/C + + libraries. For example, the SQLite library provides support for a database, the OpenGL/ES library provides support for 3D drawing, the Webkit library provides support for a browser kernel, and the like. Also provided in the system runtime library layer 340 is an Android runtime library (Android runtime), which mainly provides some core libraries that can allow developers to write Android applications using the Java language. The application framework layer 360 provides various APIs that may be used in building an application, and developers may build their own applications by using these APIs, such as activity management, window management, view management, notification management, content provider, package management, session management, resource management, and location management. At least one application program runs in the application layer 380, and the application programs may be native application programs carried by the operating system, such as a contact program, a short message program, a clock program, a camera application, and the like; or a third-party application developed by a third-party developer, such as a game application, an instant messaging program, a photo beautification program, a word translation program, and the like.

Taking an operating system as an IOS system as an example, programs and data stored in the memory 120 are shown in fig. 4, and the IOS system includes: a Core operating system Layer 420(Core OS Layer), a Core Services Layer 440(Core Services Layer), a Media Layer 460(Media Layer), and a touchable Layer 480(Cocoa Touch Layer). The kernel operating system layer 420 includes an operating system kernel, drivers, and underlying program frameworks that provide functionality closer to hardware for use by program frameworks located in the core services layer 440. The core services layer 440 provides system services and/or program frameworks, such as a Foundation framework, an account framework, an advertisement framework, a data storage framework, a network connection framework, a geographic location framework, a motion framework, and so forth, as required by the application. The media layer 460 provides audiovisual related interfaces for applications, such as graphics image related interfaces, audio technology related interfaces, video technology related interfaces, audio video transmission technology wireless playback (AirPlay) interfaces, and the like. Touchable layer 480 provides various commonly used page-related frameworks for application development, and touchable layer 480 is responsible for user touch interaction operations on the terminal. Such as a local notification service, a remote push service, an advertising framework, a game tool framework, a messaging User Interface (UI) framework, a User page UIKit framework, a map framework, and so forth.

In the framework shown in FIG. 4, the framework associated with most applications includes, but is not limited to: a base framework in the core services layer 440 and a UIKit framework in the touchable layer 480. The base framework provides many basic object classes and data types, provides the most basic system services for all applications, and is UI independent. While the class provided by the UIKit framework is the underlying UI class library for creating touch-based user pages, iOS applications can provide UIs based on the UIKit framework, so it provides the application's infrastructure for building user pages, drawing, processing and user interaction events, responding to gestures, and so on.

The Android system can be referred to as a mode and a principle for realizing data communication between the third-party application program and the operating system in the IOS system, and details are not repeated herein.

The input device 130 is used for receiving input instructions or data, and the input device 130 includes, but is not limited to, a keyboard, a mouse, a camera, a microphone, or a touch device. The output device 140 is used for outputting instructions or data, and the output device 140 includes, but is not limited to, a display device, a speaker, and the like. In one example, the input device 130 and the output device 140 may be combined, and the input device 130 and the output device 140 are touch display screens for receiving touch operations of a user on or near the touch display screens by using any suitable object such as a finger, a touch pen and the like, and displaying user pages of various applications. The touch display screen is generally provided at a front panel of the terminal. The touch display screen may be designed as a full-face screen, a curved screen, or a profiled screen. The touch display screen can also be designed to be a combination of a full-face screen and a curved-face screen, and a combination of a special-shaped screen and a curved-face screen, which is not limited in the embodiment of the present application.

In addition, those skilled in the art will appreciate that the configurations of the terminals illustrated in the above-described figures do not constitute limitations on the terminals, as the terminals may include more or less components than those illustrated, or some components may be combined, or a different arrangement of components may be used. For example, the terminal further includes a radio frequency circuit, an input unit, a sensor, an audio circuit, a wireless fidelity (WiFi) module, a power supply, a bluetooth module, and other components, which are not described herein again.

In the embodiment of the present application, the main body of execution of each step may be the terminal described above. Optionally, the execution subject of each step is an operating system of the terminal. The operating system may be an android system, an IOS system, or another operating system, which is not limited in this embodiment of the present application.

The terminal of the embodiment of the application can also be provided with a display device, and the display device can be various devices capable of realizing a display function, for example: a cathode ray tube display (CR), a light-emitting diode display (LED), an electronic ink panel, a Liquid Crystal Display (LCD), a Plasma Display Panel (PDP), and the like. The user can view information such as displayed text, images, video, etc. using the display device on the terminal 101. The terminal may be a smart phone, a tablet computer, a gaming device, an AR (Augmented Reality) device, an automobile, a data storage device, an audio playing device, a video playing device, a notebook, a desktop computing device, a wearable device such as an electronic watch, an electronic glasses, an electronic helmet, an electronic bracelet, an electronic necklace, an electronic garment, or the like.

In the terminal shown in fig. 1, the processor 110 may be configured to call an application program stored in the memory 120, and specifically execute the parameter determination method of the line speaker array according to the embodiment of the present application.

Here, a line speaker array is first described.

The types of sound sources are divided into point sound sources, line sound sources and plane sound sources according to the geometrical shapes of the sound sources, and the sound wave radiation modes of different sound sources are different.

When the size of the sound source is small relative to the wavelength or propagation distance of the sound wave and the directivity of the sound source is not strong, it can be regarded as a point sound source approximately, as shown in fig. 5(a), such as speaking, clapping, it radiates outward in the form of spherical waves.

While the noise that we often hear when a train is running, the noise that a large number of motor vehicles are running on a road, etc., can be regarded as a line sound source composed of many point sound sources, as shown in fig. 5(b), which radiate noise outward in the form of an approximately cylindrical wave.

While the planar sound source radiates outward with a plane wave, the action of the radiated sound energy on the plane is equal everywhere, as shown in fig. 5(c), and no matter what position of the listener in front of the wall of the sound box is heard, the sound source of this kind is relatively rarely used at present.

In the embodiment of the present application, a line sound source is mainly introduced, and is composed of n point sound sources which are separated by a distance of d and arranged on a straight line. Wherein, each point sound source is an array element.

A system formed by arranging a plurality of array elements according to a certain geometrical structure is an array, and if the array elements are loudspeakers, the array is called a loudspeaker array. The line loudspeaker array is a sound radiation loudspeaker with equal amplitude and same phase and closely arranged in a straight line. Each loudspeaker unit radiates a planar in-phase wave front, and the combination of multiple units can provide a single main extended sound source, and the wave fronts of the loudspeaker array can generate consistent-quality sound in a certain frequency range and a limited distance through coupling in the whole audio frequency range, so that the sound can be transmitted in a specific direction in the form of cylindrical waves. Compared with spherical waves emitted by an omnidirectional point sound source, the sound pressure decays more slowly along with the distance, and the sound source can project a longer distance.

In a line loudspeaker array, sound radiation generated by each array element propagates to an observation point, and superposition and interference occur, so that the propagation of sound has directivity.

The directivity formula of the loudspeaker array is:

where Ra is referred to as a directional angle, and is a ratio of a sound pressure level at an angle a to a sound pressure level at a 0, the directional angle at a 0 is a directional angle of a principal axis (virtual) of the array, n is the number of point sound sources constituting the array, d is a distance between adjacent sound sources, and λ is a wavelength of a point sound source signal. As can be seen from the above formula, the sound pressure and directivity of the line speaker array mainly depend on the number of array elements, the spacing between the array elements, and the frequency of the input signal, and the directivity is related to the wavelength. It is theorized that typically the energy radiated by the array is concentrated in the main lobe at low frequencies, and that side lobes occur when the cell spacing exceeds half the wavelength of the acoustic wave.

The directivity of a line speaker array is related to its own length, the minimum distance between each element and the radiated sound wave frequency. The larger the array, the better the directivity; the higher the frequency, the better the directivity.

The linear loudspeaker array directivity mainly refers to two important indexes, one is the main beam width, and the other is the side lobe level, so that the side lobe is suppressed, the space sampling theorem is met, and aliasing distortion of high-frequency signals is avoided when the high-frequency signals are transmitted through linear array columns. The requirements for constructing a line speaker array include:

the distance d between the array elements must not exceed the half wavelength of the highest frequency in the working frequency range, i.e. d is not more than lambda_min/2；

The length l of the linear sound source array is more than half of the lowest frequency wavelength in the working frequency range, i.e. l is more than or equal to lambda_max/2。

The present application is described in detail below with reference to specific examples.

In one embodiment, as shown in fig. 6, a method for determining parameters of a line speaker array is proposed, which can be implemented by means of a computer program and can be run on a parameter determination device of a line speaker array based on the von neumann system. The computer program may be integrated into the application or may run as a separate tool-like application.

Specifically, the method for determining parameters of the line speaker array includes:

s101, acquiring an initial audio signal, and performing down-sampling processing on the initial audio signal to obtain a down-sampled audio signal;

the audio signal is a regular sound wave frequency and amplitude variation information carrier with voice, music and sound effects. Audio signals can be classified into regular audio and irregular sound according to the characteristics of sound waves. Regular audio can be divided into speech, music and sound effects. Regular audio is a continuously varying analog signal that can be represented by a continuous curve called a sound wave.

The initial audio signal may be regular audio such as speech, music or sound effects. The initial audio signal is a broadband signal, lambda is v/f, lambda is the wavelength, v is the wave speed, f is the frequency, the wave speed v of the sound wave is 340 m/s generally, the frequency f of the sound heard by the human ear is 20 HZ-20 KHZ, so the wavelength lambda of the sound heard by the human ear is 0.017-17 m. Under the condition of meeting the length of the loudspeaker array, when the frequency is higher, if the array element distance is closer, the comb filtering effect is easy to generate. When the frequency is low, the main lobe range is large, and the directivity of the loudspeaker line array is poor.

The initial audio signal is a continuously varying analog signal that is sampled, quantized and encoded to obtain PCM audio data x [ n ]]Then, as shown in FIG. 7, the PCM audio data is down-sampled to obtain down-sampled audio data x_s[n]As shown in fig. 7.

Down-sampling refers to sampling a sample sequence several samples apart (at a certain sampling rate) to obtain a new sequence. The down sampling is also an information dimension reduction and can play a role in simplification.

In the process of converting analog/digital signals, when the sampling frequency fs.max is greater than 2 times of the highest frequency fmax in the signals (fs.max > -2 fmax), the digital signals after sampling completely retain the information in the original signals.

S102, acquiring the wavelength range of the down-sampling audio signal, and determining the array element spacing of the line speaker array based on the wavelength range of the down-sampling audio signal;

specifically, when the initial audio signal is down-sampled at a first sampling rate, a first down-sampled audio signal is obtained, a first wavelength range of the first down-sampled audio signal is obtained, a minimum first wavelength in the first wavelength range is obtained, and an array element pitch of the line speaker array is set to be any value of half wavelengths smaller than or equal to the minimum first wavelength. The minimum first wavelength corresponds to a maximum frequency of the operating frequencies.

Where λ is a wavelength, v is a wave velocity, and f is a frequency. The wave speed v of the sound wave is generally 340 m/s, the frequency f of the audio signal heard by the human ear is 20 HZ-20 KHZ, so the wavelength lambda range of the audio signal heard by the human ear is 0.017-17 m, and the array element spacing d is less than or equal to 0.017/2 m, which is difficult to realize. For example, the sampling rate is 8KHZ, the maximum frequency of the corresponding audio signal is 4KHZ, and therefore λ v/f 340/4000 cm, the array element distance d can be increased to nearly 4cm, which is relatively easy to implement. When the frequency is 20HZ, the length of the line array is required to be more than 8.5 meters, and the significance of portability is completely removed.

Or, acquiring a first experience threshold value, and setting the array element spacing of the line loudspeaker array to any value between the first experience threshold value and a half wavelength of the minimum first wavelength.

The first experiment can be understood as the minimum array element spacing achievable in the practical application of making a line loudspeaker array.

Or downsampling the initial audio signal according to a second sampling rate to obtain a second downsampled audio signal, downsampling the initial audio signal according to a third sampling rate to obtain a third downsampled audio signal, wherein the second sampling rate is smaller than the third sampling rate, then obtaining a second wavelength range of the second downsampled audio signal, obtaining a minimum second wavelength in the second wavelength range, obtaining a third wavelength range of the third downsampled audio signal, and obtaining a minimum third wavelength in the third wavelength range; setting an array element pitch of the line loudspeaker array to any value between a half wavelength of the minimum second wavelength and a half wavelength of the minimum third wavelength.

For example, the second sampling rate is 16KHZ, the half wavelength of the minimum second wavelength is 1cm, the second sampling rate is 8KHZ, and the half wavelength of the minimum third wavelength is 4cm, so that the array element spacing can take any value from 1cm to 4 cm.

S103, carrying out low-frequency filtering processing on the down-sampling audio signal to obtain a filtered audio signal;

a high pass filter may be used to perform low frequency filtering processing on the downsampled audio signal. Signals above a set cut-off frequency (fc) can normally pass, while low frequency signals below the cut-off frequency (fc) are blocked and attenuated.

A high pass filter is a system that passes high frequencies while blocking low frequencies. It removes low frequency components from the signal. Its characteristics can be described in the time and frequency domains by the impulse response and the frequency response, respectively. The frequency response is expressed as a function with frequency as an argument, and is generally expressed as a complex function with a complex variable j ω as an argument, and H (j ω).

The down-sampling is input to a high-pass filter, and after filtering out the low-frequency signal, a filtered audio signal (high-frequency signal) is output.

S104, acquiring the wavelength range of the filtering audio signal, and determining the length of the line sound source of the line loudspeaker array based on the wavelength range of the filtering audio signal.

Specifically, the maximum wavelength in the wavelength range of the filtered audio signal is obtained, and the line sound source length of the line speaker array is set to be greater than or equal to any value of half wavelengths of the maximum wavelength.

The maximum wavelength corresponds to the lowest frequency, the cut-off frequency. If the cut-off frequency is fc, the maximum λ is v/fc, and in this case, the minimum line source length can be v/(2 × fc).

Or acquiring a second empirical threshold, and setting the length of the line sound source of the line loudspeaker array to any value between the half wavelength of the maximum wavelength and the second empirical threshold.

The second empirical threshold may be understood to satisfy a maximum line source length for which the line loudspeaker array is miniature.

Referring to fig. 8, fig. 8 is a schematic flowchart illustrating another embodiment of a method for determining parameters of a line speaker array according to the present application. Specifically, the method comprises the following steps:

s201, acquiring an initial audio signal, and performing down-sampling processing on the initial audio signal according to a first sampling rate to obtain a first down-sampled audio signal;

The initial audio signal may be regular audio such as speech, music or sound effects. The initial audio signal is a wideband signal with a frequency range of 20HZ to 20 KHZ.

The initial audio signal is a continuously changing analog signal, the analog signal is sampled, quantized and encoded to obtain PCM audio data, and then the PCM audio data is down-sampled to obtain down-sampled audio data.

S202, acquiring a first wavelength range of the first down-sampling audio signal, and acquiring a minimum first wavelength in the first wavelength range;

for audio signals, common sampling rates include 16KHZ and 8 KHZ.

When the first sampling rate is 16KHZ, the half wavelength of the minimum first wavelength is 1cm, which is difficult to realize for the speaker array, and when the interval is close, the comb filtering effect is easy to generate.

When the first sampling rate is 8KHZ, the half wavelength of the minimum first wavelength is 4cm, which is relatively easy to implement.

In the embodiment of the present application, the first sampling rate may be 8 KHZ.

S203, acquiring a first experience threshold, and setting the array element spacing of the line loudspeaker array to be any value between the first experience threshold and a half wavelength of the minimum first wavelength;

the first empirical threshold may be understood as the minimum array element spacing achievable in the practical application to fabricate a line loudspeaker array, such as 2 cm.

The pitch of the elements of the line loudspeaker array may be set to any value between 2-4cm, such as 4 cm.

S204, carrying out low-frequency filtering processing on the down-sampling audio signal to obtain a filtered audio signal;

for low frequency signals, due to the poor directivity, a high pass filter may be used to perform low frequency filtering processing on the down-sampled audio signal. The cut-off frequency (fc) of the high-pass filter can be designed to be about 500Hz, the signal higher than the set threshold frequency (fc) can normally pass through, and the low-frequency signal 20-500 Hz lower than the set threshold frequency (fc) is blocked and attenuated.

Here, the cutoff frequency is a boundary frequency at which the output signal energy of one system starts to decrease greatly (increase greatly in the band stop filter).

For example, the high-pass filter may adopt three second-order cascade IIR filters with low computation, and the transfer function is:

wherein a is_jiI is 0,1,2 and b_jiI is 1, and 2 is a recursive coefficient. The frequency response of the IIR high pass filter is schematically shown in fig. 9.

S205, acquiring the wavelength range of the filtering audio signal, and acquiring the maximum wavelength in the wavelength range of the filtering audio signal;

if the cutoff frequency fc is 500HZ, the maximum λ v/fc 340/500 cm is 68 cm.

S206, acquiring a second empirical threshold, and setting the length of the line sound source of the line loudspeaker array to be any value between the half wavelength of the maximum wavelength and the second empirical threshold;

at this time, the minimum length of the line sound source can be 34 cm.

The second empirical threshold may be understood to satisfy a maximum line source length for a line loudspeaker array of miniature size, such as 50 cm.

Therefore, the length of the line sound source can be set to be 34-50 cm.

And S207, generating the line loudspeaker array based on the array element spacing and the line sound source length.

After the array element spacing and the length of the line sound source are determined, the shape of the line loudspeaker array can be determined, and then the loudspeaker can be manufactured.

In the embodiment of the application, an initial audio signal is obtained, downsampling processing is performed on the initial audio signal to obtain a downsampled audio signal, the wavelength range of the downsampled audio signal is obtained, the array element spacing of a line loudspeaker array is determined based on the wavelength range of the downsampled audio signal, a comb filtering effect of a high-frequency signal can be avoided, and then low-frequency filtering processing is performed on the downsampled audio signal to obtain a filtered audio signal; the wavelength range of the filtering audio signal is obtained, the length of a linear sound source of the linear loudspeaker array is determined based on the wavelength range of the filtering audio signal, and the directivity of the low-frequency signal can be improved. Can satisfy and carry out the balance in line speaker array size and the directive property, be fit for miniature line speaker array. The size is small and exquisite, and the portability is strong, does benefit to extensive popularization.

Referring to fig. 10, fig. 10 is a schematic flowchart illustrating a method for determining parameters of a line speaker array according to another embodiment of the present disclosure. Specifically, the method comprises the following steps:

s301, acquiring an initial audio signal, and performing down-sampling processing on the initial audio signal according to a second sampling rate to obtain a second down-sampled audio signal;

the initial audio signal is a broadband audio signal, and can be regular audio such as voice, music or sound effect.

The initial audio signal is a continuously varying analog signal, which is sampled, quantized and encoded to obtain PCM audio data, which is down-sampled at a second sampling rate to adjust the frequency range of the audio signal.

For example, the second sampling rate may be 8 KHZ.

S302, performing downsampling processing on the initial audio signal according to a third sampling rate to obtain a third downsampled audio signal, wherein the second sampling rate is smaller than the third sampling rate;

similarly, the PCM audio data is down-sampled at a third sampling rate to adjust the frequency range of the audio signal.

For example, the third sampling rate is less than the second sampling rate, which may be 16 KHZ.

S303, obtaining a second wavelength range of the second down-sampled audio signal, and obtaining a minimum second wavelength in the second wavelength range;

if the third sampling rate can be 8KHZ, the minimum third wavelength is 8 cm.

S304, obtaining a third wavelength range of the third down-sampled audio signal, and obtaining a minimum third wavelength in the third wavelength range;

if the third sampling rate can be 16KHZ, the minimum third wavelength is 2 cm.

S305, setting the array element spacing of the line loudspeaker array to be any value between the half wavelength of the minimum second wavelength and the half wavelength of the minimum third wavelength;

therefore, the array element interval can be set to be 1-4 cm.

S306, carrying out low-frequency filtering processing on the down-sampling audio signal to obtain a filtered audio signal;

s307, acquiring the wavelength range of the filtering audio signal, and acquiring the maximum wavelength in the wavelength range of the filtering audio signal;

s308, acquiring a second empirical threshold, and setting the length of the line sound source of the line loudspeaker array to be any value between the half wavelength of the maximum wavelength and the second empirical threshold;

s309, generating the line loudspeaker array based on the array element distance and the length of the line sound source.

S306-S309 can be referred to as S204-S207, and are not described herein.

The following are embodiments of the apparatus of the present application that may be used to perform embodiments of the method of the present application. For details which are not disclosed in the embodiments of the apparatus of the present application, reference is made to the embodiments of the method of the present application.

Please refer to fig. 11, which shows a schematic structural diagram of a parameter determining apparatus for a line speaker array according to an exemplary embodiment of the present application. The parameter determination means of the line speaker array may be implemented as all or part of the terminal by software, hardware or a combination of both. The device 1 comprises a downsampling processing module 11, an array element spacing determining module 12, a low-frequency filtering module 13 and a line sound source length determining module 14.

The down-sampling processing module 11 is configured to acquire an initial audio signal, and perform down-sampling processing on the initial audio signal to obtain a down-sampled audio signal;

an array element spacing determining module 12, configured to obtain a wavelength range of the downsampled audio signal, and determine an array element spacing of the line speaker array based on the wavelength range of the downsampled audio signal;

a low-frequency filtering module 13, configured to perform low-frequency filtering processing on the downsampled audio signal to obtain a filtered audio signal;

and a line sound source length determining module 14, configured to obtain a wavelength range of the filtered audio signal, and determine a line sound source length of the line speaker array based on the wavelength range of the filtered audio signal.

Optionally, the downsampling processing module 11 is specifically configured to:

carrying out down-sampling processing on the initial audio signal according to a first sampling rate to obtain a first down-sampled audio signal;

the array element interval determining module 12 is specifically configured to:

acquiring a first wavelength range of the first down-sampled audio signal, acquiring a minimum first wavelength in the first wavelength range, and setting an array element interval of the line speaker array to be smaller than or equal to any value in half wavelengths of the minimum first wavelength.

Optionally, the array element interval determining module 12 is specifically configured to:

acquiring a first experience threshold;

setting an array element spacing of the line loudspeaker array to any value between the first empirical threshold and a half wavelength of the minimum first wavelength.

carrying out down-sampling processing on the initial audio signal according to a second sampling rate to obtain a second down-sampled audio signal;

performing downsampling processing on the initial audio signal according to a third sampling rate to obtain a third downsampled audio signal, wherein the second sampling rate is smaller than the third sampling rate;

the array element interval determining module 12 is specifically configured to:

acquiring a second wavelength range of the second down-sampled audio signal, and acquiring a minimum second wavelength in the second wavelength range;

acquiring a third wavelength range of the third down-sampled audio signal, and acquiring a minimum third wavelength in the third wavelength range;

setting an array element pitch of the line loudspeaker array to any value between a half wavelength of the minimum second wavelength and a half wavelength of the minimum third wavelength.

Optionally, the line sound source length determining module 14 is specifically configured to:

and acquiring the maximum wavelength in the wavelength range of the filtered audio signal, and setting the length of the line sound source of the line loudspeaker array to be larger than or equal to any value in half wavelength of the maximum wavelength.

acquiring a second empirical threshold;

setting a line source length of the line speaker array to any value between a half wavelength of the maximum wavelength and the second empirical threshold.

Optionally, as shown in fig. 12, the apparatus further includes:

an array generating module 15, configured to generate the line speaker array based on the array element spacing and the line sound source length.

It should be noted that, when the parameter determining apparatus for a line speaker array provided in the foregoing embodiment executes the parameter determining method for a line speaker array, the division of the functional modules is merely used as an example, and in practical applications, the function distribution may be completed by different functional modules according to needs, that is, the internal structure of the apparatus may be divided into different functional modules to complete all or part of the functions described above. In addition, the parameter determining apparatus for a line speaker array and the parameter determining method embodiment for a line speaker array provided in the above embodiments belong to the same concept, and details of implementation processes thereof are referred to as method embodiments, and are not described herein again.

The above-mentioned serial numbers of the embodiments of the present application are merely for description and do not represent the merits of the embodiments.

An embodiment of the present application further provides a computer storage medium, where the computer storage medium may store a plurality of instructions, where the instructions are suitable for being loaded by a processor and executing the method steps in the embodiments shown in fig. 5 to 10, and a specific execution process may refer to specific descriptions of the embodiments shown in fig. 5 to 10, which are not described herein again.

It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by a computer program, which can be stored in a computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. The storage medium may be a magnetic disk, an optical disk, a read-only memory or a random access memory.

The above disclosure is only for the purpose of illustrating the preferred embodiments of the present application and is not to be construed as limiting the scope of the present application, so that the present application is not limited thereto, and all equivalent variations and modifications can be made to the present application.

Claims

1. A method for determining parameters of a line speaker array, the method comprising:

2. The method of claim 1, wherein the down-sampling the initial audio signal to obtain a down-sampled audio signal comprises:

the acquiring the wavelength range of the down-sampling audio signal, and determining the array element spacing of the line speaker array based on the wavelength range of the down-sampling audio signal, includes:

3. The method of claim 2, wherein setting the pitch of the elements of the line speaker array to any value less than or equal to one half of the wavelength of the smallest first wavelength comprises:

acquiring a first experience threshold;

4. The method of claim 1, wherein the down-sampling the initial audio signal to obtain a down-sampled audio signal comprises:

5. The method of claim 1, wherein determining a line sound source length for the line speaker array based on the wavelength range of the filtered audio signal comprises:

6. The method of claim 5, wherein said setting a line source length of the line speaker array to be greater than or equal to any one of half wavelengths of the maximum wavelength comprises:

acquiring a second empirical threshold;

7. The method according to any one of claims 1-6, further comprising:

and generating the line loudspeaker array based on the array element spacing and the length of the line sound source.

8. An apparatus for determining parameters of a line speaker array, the apparatus comprising:

9. A computer storage medium, characterized in that it stores a plurality of instructions adapted to be loaded by a processor and to carry out the method steps according to any one of claims 1 to 7.

10. A terminal, comprising: a processor and a memory; wherein the memory stores a computer program adapted to be loaded by the processor and to perform the method steps of any of claims 1 to 7.