METHOD AND APPARATUS FOR OBTAINING AN HOA COEFFICIENT.

Abstract

This application provides a method and apparatus for obtaining an HOA coefficient. The method for obtaining an HOA coefficient includes: obtaining location information of a virtual loudspeaker on a pre-established spherical surface, where the pre-established spherical surface includes M circles of longitude and N circles of latitude;to obtain, based on location information and a pre-established reference trigonometric function table, a trigonometric function value corresponding to the location information, wherein the reference trigonometric function table includes an elevation trigonometric function table and / or an azimuth trigonometric function table, the elevation trigonometric function table includes a plurality of trigonometric function values ​​corresponding to the elevation indices of a plurality of first reference points in a first longitude circle, the first longitude circle being one of the M longitude circles, the azimuth trigonometric function table includes a plurality of trigonometric function values ​​corresponding to the azimuth indices of a plurality of second reference points in a first latitude circle, and the first latitude circle being one of the N latitude circles;and obtain an HOA coefficient for the virtual speaker based on the value of the trigonometric function corresponding to the location information. In this application, a certain amount of computation can be reduced in a preliminary stage and storage space can be saved.

Description

METHOD AND APPARATUS FOR OBTAINING AN HOA COEFFICIENT Accn Ln / eznz / e / YiAi CROSS REFERENCE TO RELATED APPLICATIONS This application claims priority to Chinese Patent Application No. 202110246382.6, filed with the Chinese National Intellectual Property Administration on March 5, 2021, and entitled METHOD AND APPARATUS FOR OBTAINING AN HOA COEFFICIENT, which is incorporated herein by reference in its entirety. TECHNICAL FIELD OF THE INVENTION This application relates to audio processing technologies, and in particular to a method and apparatus for obtaining an HOA coefficient. BACKGROUND OF THE INVENTION A three-dimensional audio technology is an audio technology that acquires, processes, transmits, renders, and reproduces sound events and three-dimensional sound field information in the real world using a computer, signal processing, or similar equipment. Three-dimensional audio technology imbues sound with a strong sense of space, envelopment, and immersion, providing listeners with an “surround” listening experience. Currently, a conventional three-dimensional audio technology is a higher-order ambisonics (HOA) technology. HOA technology has the following characteristics: recording and encoding are relevant to the design of a loudspeaker at a playback stage, and the data in an HOA format is rotary. Therefore, HOA technology offers greater flexibility in three-dimensional audio reproduction and has thus garnered more attention and research. In HOA technology, an HOA signal is converted into a real loudspeaker signal for playback; or an HOA signal is converted into a virtual loudspeaker signal, and then the virtual loudspeaker signal is mapped to a binaural signal for playback. In the above process, calculating an HOA coefficient is a key step. In this related technology, an HOA coefficient is calculated based on a spherical harmonic expansion formula of order P. However, in the previous method, the amount of computation is large, and the storage space requirement is high. BRIEF DESCRIPTION OF THE INVENTION This application provides a method and apparatus for obtaining an HOA coefficient, to reduce the amount of calculation at a preliminary stage and save storage space. According to a first aspect, this application provides a method for obtaining an HOA coefficient, including: obtaining location information of a virtual loudspeaker on a pre-established spherical surface, where the location information includes elevation and / or azimuth information, the pre-established spherical surface includes M circles of longitude and N circles of latitude, an intersection between the circle of longitude and the circle of latitude is referred to as a reference point, N reference points located on a circle of longitude are arranged at equal intervals, and the M reference points located on a circle of latitude are arranged at equal intervals; obtaining, based on the location information and a table of pre-established reference trigonometric functions, a trigonometric function value corresponding to the location information,where the reference trigonometric function table includes an elevation trigonometric function table and / or an azimuth trigonometric function table, the elevation trigonometric function table includes a plurality of trigonometric function values ​​corresponding to the elevation information of a plurality of first reference points, the plurality of first reference points being reference points on a first longitude circle, a quantity of the plurality of first reference points not less than [N / 4J+1, ( ] indicates rounding down, the first longitude circle being one of the M longitude circles, the azimuth trigonometric function table includes a plurality of trigonometric function values ​​corresponding to the azimuth information of a plurality of second reference points, the plurality of second reference points being reference points on a first latitude circle,a quantity of the plurality of second reference points is not less than [M / 4J+1, and the first circle of latitude is one of the N circles of latitude; and obtain a higher-order ambisonic coefficient HOA for the virtual loudspeaker based on the value of the trigonometric function corresponding to the location information. In this application, only the trigonometric function values ​​(a table of elevation trigonometric functions) for one-quarter of all reference points on a longitude circle on the predefined spherical surface and / or trigonometric function values ​​(a table of azimuth trigonometric functions) for one-quarter of all reference points on a latitude circle on the predefined spherical surface need to be obtained beforehand. The trigonometric function values ​​for any angle between 0° and 360° can then be obtained from the trigonometric function table. This reduces the amount of computation at a preliminary stage. Furthermore, because the number of angles in the trigonometric function table is reduced, the amount of data that needs to be stored is also reduced accordingly, thus saving storage space. The pre-established spherical surface includes the M circles of longitude and the N circles of latitude; the intersection between the circle of longitude and the circle of latitude is known as the Rccn Ln / cznz / e / YiAi reference point, N reference points located on a longitude circle are arranged at equal intervals, the M reference points located on a latitude circle are arranged at equal intervals. To ensure that the reference points can cover as many virtual speakers as possible, the following condition can be met: M x N>K, where K is a total number of virtual speakers. For example, a value of K could be 2048, 1024, or 530.In this application, because the azimuth information between each two adjacent longitude circles is equal, i.e., the M longitude circles are evenly distributed on the spherical surface, N reference points located on a longitude circle are arranged at equal intervals; and because the elevation information between each two adjacent latitude circles is equal, i.e., the N latitude circles are evenly distributed on the spherical surface, the M reference points located on a latitude circle are arranged at equal intervals.Consequently, because N reference points located on a circle of longitude are arranged at equal intervals, the elevation information differences between any two adjacent reference points located on a circle of longitude are equal; and because N reference points located on a circle of longitude are arranged at equal intervals, the azimuth information differences between any two adjacent reference points located on a circle of longitude are equal. The virtual speaker can be any virtual speaker arranged for sound reproduction. The virtual speaker's location information on the spherical surface includes elevation and / or azimuth information. An angle between a horizontal plane (for example, a plane containing the equator) and a connecting line between a virtual speaker location and the Earth's center is the elevation information (also known as the angle with the horizon) of the virtual speaker's location information; and an angle between a specified starting direction and a projection, onto the horizontal plane, of the connecting line between the virtual speaker location and the Earth's center is the azimuth information of the virtual speaker's location information. Optionally, the azimuth information in this application may also be referred to as azimuth. The reference trigonometric functions table includes the elevation trigonometric functions table and / or the azimuth trigonometric functions table. The table of trigonometric elevation functions includes the plurality of trigonometric function values ​​corresponding to the elevation information of the plurality of first reference points. The plurality of first reference points are reference points on the first longitude circle. The number of first reference points is not less than [N / 4J+1], where [j] indicates rounding down. The first longitude circle is one of the M longitude circles. Rccn Ln / eznz / e / YiAi In this application, any of the M circles of longitude is selected as the first circle of longitude, and the reference points (i.e., the plurality of first reference points) used to calculate the table of trigonometric elevation functions are selected from the N reference points on the first circle of longitude. According to the principle of a trigonometric function, an angle range from 0° (0) to 360° (2π) can be divided into four subranges: 0° (0) to 90° (π / 2), 90° (π / 2) to 180° (π), 180° (π) to 270° (3π / 2), and 270° (3π / 2) to 360° (2π). A trigonometric function value calculated using any of the four subranges can be extended to a trigonometric function value within the angle range of 0° (0) to 360° (2π). Therefore, in this application, during the selection of the plurality of first reference points, the quantity of the plurality of first reference points is not less than [N / 4J+1.To be specific, at least a quarter of the N reference points in the first longitude circle are selected as the plurality of the first reference points. Optionally, the elevation information for the plurality of first reference points can belong to one of four subranges. For example, the elevation information for the plurality of first reference points is within the subrange from 0°(0) to 90°(π / 2), or the elevation information for the plurality of first reference points is within the subrange from 90°(π / 2) to 180°(π), or the elevation information for the plurality of first reference points is within the subrange from 180°(3π) to 270°(π / 2), or the elevation information for the plurality of first reference points is within the subrange from 270°(3π / 2) to 360°(2π). Optionally, the elevation information of the plurality of first reference points may belong to at least two of the four subranges. For example, the elevation information of a first part of the plurality of first reference points is within the subrange from 0°(0) to 90°(π / 2), and the elevation information of a second part of the reference points is within the subrange from 90°(π / 2) to 180°(π), where the elevation information of the two parts of the reference points does not overlap during the calculation of a trigonometric function value;or the elevation information of one part of the plurality of the first reference points is within the sub-range of 90° (π / 2) to 180° (π), and the elevation information of another part of the reference points is within the sub-range of 180° (π) to 270° (3π / 2), wherein the elevation information of the two parts of the reference points does not overlap during the calculation of a trigonometric function value; or the elevation information of one part of the plurality of the first reference points is within the sub-range of 180° (π) to 270° (3π / 2), and the elevation information of another part of the reference points is within the sub-range of 270° (3π / 2) to 360° (2π), wherein the elevation information of the two parts of the reference points does not overlap during the calculation of a trigonometric function value; or the elevation information of a first one; Rccn Ln / eznz / e / YiAi part of the plurality of the first reference points is within the subrange of 0° (0) to 90° (tt / 2), the elevation information of a second part of the reference points is within the subrange of 90° (ττ / 2) to 180° (π), and the elevation information of a third part of the reference points is within the subrange of 180° (π) to 270° (3π / 2), wherein the elevation information of the three parts of the reference points does not overlap during the calculation of a trigonometric function value;or the elevation information of a first part of the plurality of the first reference points is within the subrange of 90° (tt / 2) to 180° (π), the elevation information of a second part of the reference points is within the subrange of 180° (π) to 270° (3π / 2), and the elevation information of a third part of the reference points is within the subrange of 270° (3π / 2) to 360° (2tt), wherein the elevation information of the three parts of the reference points does not overlap during the calculation of a trigonometric function value;or the elevation information of a first part of the plurality of the first reference points is within the subrange of 0° (0) to 90° (tt / 2), the elevation information of a second part of the reference points is within the subrange of 90° (tt / 2) to 180° (π), the elevation information of a third part of the reference points is within the subrange of 180° (π) to 270° (3π / 2), and the elevation information of a fourth part of the reference points is within the subrange of 270° (3π / 2) to 360° (2π), wherein the elevation information of the four parts of the reference points does not overlap during the calculation of a trigonometric function value. The lack of overlap can mean that the trigonometric function values ​​calculated using elevation information belonging to different subranges are not equal. For example, there are a total of four first reference points (n1, n2, n3, and n4), where the elevation information for n1 is 0, the elevation information for n2 is π / 6, the elevation information for n3 is tt / 3, and the elevation information for n4 is tt / 2; or the elevation information for n1 is 0, the elevation information for n2 is 2 / 3tt, the elevation information for n3 is 4 / 3tt, and the elevation information for n4 is 2tt.It should be noted that, in this application, a subrange to which the elevation information of the plurality of first reference points belongs is not specifically limited, provided that the trigonometric function values ​​of the elevation information of the plurality of first reference points can cover the trigonometric function values ​​at all angles within one of the subranges. Consequently, a range of values ​​for the elevation information of the location information is from 0 to 2tt. Rccn Ln / eznz / e / YiAi In this application, the plurality of trigonometric functions corresponding to the elevation information of the plurality of first reference points can be sinusoidal function values ​​or cosine function values. Optionally, a sinusoidal function value corresponding to the elevation information of a first reference point satisfies the following formula (1): sin _table_N(i) = sin x (1), where i=0,1, ..., and N', N'=[N / 4J, yr¡ indicates a radius of the first circle of length. Optionally, a cosine function value corresponding to the elevation information of a first reference point satisfies the following formula (2): eos _table_N(i) = eos xi) (2), where i=0,1, ..., and N', N'= [N / 4J, yr¡ indicates a radius of the first circle of length. The table of trigonometric azimuth functions includes the plurality of trigonometric function values ​​corresponding to the azimuth information of the plurality of second reference points. The plurality of second reference points are reference points on the first circle of latitude. The number of the plurality of second reference points is not less than |M / 4]+1, where [ ] indicates rounding down. The first circle of latitude is one of the N circles of latitude. In this application, any of the N circles of latitude is selected as the first circle of latitude, and the reference points (i.e., the plurality of the second reference points) used to calculate the table of trigonometric azimuth functions are selected from the M reference points on the first circle of latitude. Similarly, according to the principle of a trigonometric function, an angle range from 0° to 360° (2π) can be divided into four subranges: 0° to 90° (π / 2), 90° to 180°, 180° to 270°, and 270° to 360°. A trigonometric function value calculated using any of the four subranges can be extended to a trigonometric function value within the angle range of 0° (0) to 360° (2π). Therefore, in this application, during the selection of the plurality of second reference points, the number of the plurality of second reference points is not less than [M / 4J+1].To be specific, at least a quarter of the M reference points in the first latitude circle are selected as the plurality of second reference points. Optionally, the azimuth information for the plurality of second reference points can belong to one of four subranges. For example, the azimuth information for the plurality of second reference points is within the subrange from 0° to 90° (π / 2), or the azimuth information for the plurality of second reference points is within the subrange from 90° (π / 2) to 180° (π), or the azimuth information for the plurality of second reference points is within the subrange from 180° (π) to 270° (3π / 2), or the Rccn Ln / eznz / e / YiAi azimuth information of the plurality of second reference points is within the subrange of 270° (3π / 2) to 360° (2π). Optionally, the azimuth information of the plurality of second reference points may belong to at least two of the four subranges. For example, the azimuth information of a first part of the plurality of second reference points is within the subrange of 0°(0) to 90°(tt / 2), and the azimuth information of a second part of the reference points is within the subrange of 90°(tt / 2) to 180°(π), where the azimuth information of the two parts of reference points does not overlap during the calculation of a trigonometric function value;or the azimuth information of a first part of the plurality of second reference points is within the sub-range of 90° (tt / 2) to 180° (π), and the azimuth information of a second part of the reference points is within the sub-range of 180° (π) to 270° (3π / 2), wherein the azimuth information of the two parts of the reference points does not overlap during the calculation of a trigonometric function value; or the azimuth information of a first part of the plurality of second reference points is within the sub-range of 180° (π) to 270° (3π / 2), and the azimuth information of a second part of the reference points is within the sub-range of 270° (3π / 2) to 360° (2tt), wherein the azimuth information of the two parts of the reference points does not overlap during the calculation of a trigonometric function value;or the azimuth information of a first part of the plurality of second reference points is within the subrange of 0° (0) to 90° (tt / 2), the azimuth information of a second part of the reference points is within the subrange of 90° (tt / 2) to 180° (π), and the azimuth information of a third part of the reference points is within the subrange of 180° (π) to 270° (3π / 2), wherein the azimuth information of the three parts of the reference points does not overlap during the calculation of a trigonometric function value;or the azimuth information of a first part of the plurality of second reference points is within the subrange of 90° (tt / 2) to 180° (π), the azimuth information of a second part of the reference points is within the subrange of 180° (π) to 270° (3π / 2), and the azimuth information of a third part of the reference points is within the subrange of 270° (3π / 2) to 360° (2tt), wherein the azimuth information of the three parts of the reference points does not overlap during the calculation of a trigonometric function value;or the azimuth information of a first part of the plurality of second reference points is within the subrange of 0°(0) to 90° (tt / 2), the azimuth information of a second part of the reference points is within the subrange of 90° (tt / 2) to 180° (π), the azimuth information of a third part of the reference points is within the subrange of 180° (π) to 270° (3τ / 2), and the azimuth information of a fourth part of the reference points is within the subrange of 270° (3π / 2) to 360° (2tt), wherein the azimuth information of the four parts of the reference points is not; Rccn Ln / eznz / e / YiAi overlaps during the calculation of a trigonometric function value. The lack of overlap can mean that the trigonometric function values ​​calculated using azimuth information belonging to different subranges are not equal. For example, there are a total of four second reference points (n1, n2, n3, and n4), where the azimuth information for n1 is 0, the azimuth information for n2 is tt / 6, the azimuth information for n3 is π / 3, and the azimuth information for n4 is π / 2; or the azimuth information for n1 is 0, the azimuth information for n2 is 2 / 3π, the azimuth information for n3 is 4 / 3tt, and the azimuth information for n4 is 2tt. It should be noted that, in this application, a subrange to which the azimuth information of the plurality of second reference points belongs is not specifically limited, provided that the trigonometric function values ​​of the azimuth information of the plurality of second reference points can cover the trigonometric function values ​​at all angles within one of the subranges. Consequently, a range of values ​​for the azimuth information of the location information is from 0 to 2tt. In this application, the plurality of trigonometric functions corresponding to the azimuth information of the plurality of second reference points can be sinusoidal function values ​​or cosine function values. Optionally, a sinusoidal function value corresponding to the azimuth information of a second reference point satisfies the following formula (3): sin _table_M(j) = sin x (3), where j=0,1, ..., and M', M'=[M / 4J, and η indicates a radius of the first circle of latitude. Optionally, a cosine function value corresponding to the azimuth information of a second reference point satisfies the following formula (4): eos _table_M(j) = eos x (4), where j=0,1, ..., and M', M'=[M / 4J, and η indicates a radius of the first circle of latitude. It should be noted that the elevation trigonometric function table and the azimuth trigonometric function table can be calculated and stored in advance, or they can be calculated and stored in real time based on the M and N values. Optionally, since both an encoder and a decoder perform framing, during the calculation of the HOA coefficient, when an M value from a current audio frame is equal to an M value from a previous audio frame, it may not be necessary to recalculate an azimuth trigonometric function table during the processing of the current frame, and an azimuth trigonometric function table from the previous audio frame can be used directly; and when an N value from the current audio frame is equal to a value Rccn Ln / eznz / e / YiAi of N from the previous audio frame, it may not be necessary to recalculate a table of lifting trigonometric functions during the processing of the current frame, and a table of lifting trigonometric functions from the previous audio frame can be used directly. In this application, a trigonometric function value corresponding to the elevation information of the virtual speaker's location information on the preset spherical surface can be obtained based on the elevation information of the location information and the elevation trigonometric function table, and / or a trigonometric function value corresponding to the azimuth information of the virtual speaker's location information on the preset spherical surface can be obtained based on the azimuth information of the location information and the azimuth trigonometric function table. It can be learned that, for the location information of the virtual speaker on the preset spherical surface, the value of the trigonometric function corresponding to the location information can be obtained based on the specific content included in the location information and the specific content of the preset reference trigonometric function table. To be specific, the location information includes elevation information, and the value of the trigonometric function corresponding to the elevation information of the location information can be obtained based on the elevation information and the reference trigonometric function table (if an elevation trigonometric function table exists, the elevation trigonometric function table is used; or if an elevation trigonometric function table does not exist, the azimuth trigonometric function table is used).and the location information includes the azimuth information, and the value of the trigonometric function corresponding to the azimuth information of the location information can be obtained based on the azimuth information and the reference trigonometric function table (if there is an azimuth trigonometric function table, the azimuth trigonometric function table is used; or if there is no azimuth trigonometric function table, the elevation trigonometric function table is used). In this application, the value of the trigonometric function corresponding to the elevation information of the location information can be obtained using the following methods: 1. When the elevation information of the location information is equal to the elevation information of a reference point of the plurality of first reference points, a trigonometric function value found in the table of trigonometric functions of elevation and corresponding to the elevation information of the reference point is used as the trigonometric function value corresponding to the elevation information of the location information. That the elevation information of the location information is equal to the Rccn Ln / eznz / e / YiAi elevation information from a reference point of the plurality of first reference points indicates that the elevation information corresponding to a location of the virtual speaker on the preset spherical surface is exactly equal to an angle in the table of trigonometric elevation functions. Specifically, the location of the virtual speaker on the preset spherical surface coincides with a location of a reference point selected to obtain the table of trigonometric elevation functions. Therefore, the value of the trigonometric function for the elevation information can be directly obtained from the table of trigonometric elevation functions. 2. When the elevation information of the location information is equal to the elevation information of a reference point of N distinct reference points of the plurality of the first reference points, the elevation information of the location information is converted into the elevation information of a reference point of the plurality of first reference points, and a trigonometric function value found in the table of trigonometric functions of elevation and corresponding to the elevation information of the reference point is used as the trigonometric function value corresponding to the elevation information of the location information. The fact that the elevation information of the location information is equal to the elevation information of a reference point of N distinct reference points of the plurality of the first reference points indicates that the elevation information corresponding to a location of the virtual speaker on the predefined spherical surface does not belong to an angle in the table of trigonometric functions of elevation, and is equal to the elevation information of another reference point in the first circle of length, to be specific, the location of the virtual speaker on the predefined spherical surface coincides with a location of a reference point, where the reference point is not used to obtain the table of trigonometric functions of elevation, but the elevation information of the reference point has a trigonometric function correspondence with an angle in the table of trigonometric functions.Therefore, the elevation information of the location information can be converted into elevation information of a reference point of the plurality of first reference points according to a principle of a trigonometric function; and then a trigonometric function value corresponding to the elevation information of the reference point of the plurality of first reference points is obtained through table lookup, and the trigonometric function value corresponding to the elevation information of the reference point of the plurality of first reference points is used as the trigonometric function value corresponding to the elevation information of the location information. 3. When the elevation information of the location information is not equal to the Rccn Ln / eznz / e / YiAi elevation information of any reference point, the elevation information of a reference point corresponding to the location information is obtained based on the elevation information of the location information. When the elevation information of the reference point corresponding to the location information is equal to the elevation information of a reference point of the plurality of first reference points, a trigonometric function value found in the table of trigonometric functions of elevation and corresponding to the elevation information of the reference point is used as the trigonometric function value corresponding to the elevation information of the location information.When the elevation information of the reference point corresponding to the location information is equal to the elevation information of a reference point of N distinct reference points of the plurality of first reference points, the elevation information of the reference point corresponding to the location information is converted into the elevation information of a reference point of the plurality of first reference points, and a trigonometric function value found in the table of trigonometric functions of elevation and corresponding to the elevation information of the reference point is used as the trigonometric function value corresponding to the elevation information of the location information. The fact that the elevation information of the location data is not equal to the elevation information of any reference point indicates that a virtual speaker's location on the preset spherical surface is neither on a circle of longitude nor a circle of latitude. Therefore, the elevation information of the reference point corresponding to the location data is obtained first; then, the value of the trigonometric function corresponding to the elevation information of the reference point is obtained according to Method 1 or Method 2, and the value of the trigonometric function corresponding to the elevation information of the reference point is used as the value of the trigonometric function corresponding to the elevation information of the location data. Optionally, location information can be represented using an index, and the index can include an elevation index and an azimuth index. For example, on any circle of latitude, the azimuth of a landmark not distributed across the circle is set to 0, and then a corresponding azimuth index is obtained through conversion based on a pre-established conversion formula between an azimuth and an azimuth index. Because the azimuth differences between any adjacent landmarks on the circle of latitude are equal, azimuths of other landmarks on the circle of latitude can be obtained, and the azimuth indices of those other landmarks are obtained based on the conversion formula. It should be noted that a specific landmark on the circle of latitude whose azimuth is set to 0 is not specifically... Rccn Ln / eznz / e / YiAi is limited in this application. Similarly, because the elevation differences between adjacent reference points along a direction of a circle of longitude meet the above requirement, after a reference point with an elevation of 0 is established, elevations of other reference points can be obtained, and the elevation indices of all reference points on the circle of longitude can be obtained based on a predefined conversion formula between an elevation and an elevation index. It should be noted that a specific reference point on the circle of longitude with an elevation of 0 is not specifically limited in this application. For example, the reference point could be a reference point on the equator, a reference point at the South Pole, or a reference point at the North Pole. Optionally, the elevation φ and the φ' index of the elevation information comply with the following formula (5) (to be specific, a conversion formula between an elevation and an elevation index): φ' = round (—-—) (5), where \2nr¿x / V / v' r¡ indicates a radius of the first circle of length, and round() indicates the rounding. In this application, the value of the trigonometric function corresponding to the azimuth information of the location information can be obtained using the following methods. 1. When the azimuth information of the location information is equal to the azimuth information of a reference point of the plurality of second reference points, a trigonometric function value found in the table of azimuth trigonometric functions and corresponding to the azimuth information of the reference point is used as the trigonometric function value corresponding to the azimuth information of the location information. The fact that the azimuth information of the location data is equal to the azimuth information of a reference point from the plurality of second reference points indicates that the azimuth information corresponding to a location of the virtual speaker on the preset spherical surface is exactly equal to an angle in the azimuth trigonometric function table. Specifically, the location of the virtual speaker on the preset spherical surface coincides with a location of a reference point selected to obtain the azimuth trigonometric function table. Therefore, the value of the azimuth trigonometric function can be directly obtained from the azimuth trigonometric function table. 2. When the azimuth information of the location information is equal to the azimuth information of a reference point of M different reference points of the Rccn Ln / eznz / e / YiAi plurality of second reference points, the azimuth information of the location information is converted into the azimuth information of a reference point of the plurality of second reference points, and a trigonometric function value found in the table of trigonometric functions of azimuth and corresponding to the azimuth information of the reference point is used as the trigonometric function value corresponding to the azimuth information of the location information. That the azimuth information of the location information is equal to the azimuth information of a reference point of M distinct reference points of the plurality of second reference points indicates that the azimuth information corresponding to a location of the virtual speaker on the preset spherical surface does not belong to an angle in the table of trigonometric azimuth functions, and is equal to the azimuth information of another reference point on the first circle of longitude, to be specific, the location of the virtual speaker on the preset spherical surface coincides with a location of a reference point, where the reference point is not used to obtain the table of trigonometric azimuth functions, but the azimuth information of the reference point has a trigonometric function correspondence with an angle in the table of trigonometric functions.Therefore, the azimuth information of the location information can be converted into azimuth information of a reference point of the plurality of second reference points according to a principle of a trigonometric function; and then a trigonometric function value corresponding to the azimuth information of the reference point of the plurality of second reference points is obtained through table lookup, and the trigonometric function value corresponding to the azimuth information of the reference point of the plurality of second reference points is used as the trigonometric function value corresponding to the azimuth information of the location information. 3. When the azimuth information of the location information is not equal to the azimuth information of any reference point, the azimuth information of a reference point corresponding to the location information is obtained based on the azimuth information of the location information. When the azimuth information of the reference point corresponding to the location information is equal to the azimuth information of a reference point among the plurality of second reference points, a trigonometric function value found in the table of azimuth trigonometric functions that corresponds to the azimuth information of the reference point is used as the trigonometric function value corresponding to the azimuth information of the location information.When the azimuth information of the reference point corresponding to the location information is equal to the azimuth information of a reference point of M. Rccn Ln / eznz / e / YiAi reference points other than the plurality of second reference points, the azimuth information of the reference point corresponding to the location information is converted into azimuth information of a reference point of the plurality of second reference points, and a trigonometric function value found in the table of trigonometric functions of azimuth and corresponding to the azimuth information of the reference point is used as the trigonometric function value corresponding to the azimuth information of the location information. The fact that the azimuth information of the location information is not equal to the azimuth information of any reference point indicates that a location of the virtual speaker on the preset spherical surface is neither on a circle of longitude nor on a circle of latitude. Therefore, the azimuth information of the reference point corresponding to the location information is obtained first; and then the value of the trigonometric function corresponding to the azimuth information of the reference point is obtained according to method 1 or method 2, and the value of the trigonometric function corresponding to the azimuth information of the reference point is used as the value of the trigonometric function corresponding to the azimuth information of the location information. Optionally, the azimuth Θ and the index θ' of the azimuth information comply with the following formula (6) (to be specific, a conversion formula between an azimuth and an azimuth index): (Θ \ ------- (6), where η indicates a radius of the first circle of latitude, and round() indicates rounding. In this application, only the trigonometric function values ​​(a table of elevation trigonometric functions) for one-quarter of all reference points on a longitude circle on the predefined spherical surface and / or trigonometric function values ​​(a table of azimuth trigonometric functions) for one-quarter of all reference points on a latitude circle on the predefined spherical surface need to be obtained beforehand. The trigonometric function values ​​for any angle between 0° and 360° can then be obtained from the trigonometric function table. This reduces the amount of computation at a preliminary stage. Furthermore, because the number of angles in the trigonometric function table is reduced, the amount of data that needs to be stored is also reduced accordingly, thus saving storage space. According to a second aspect, this application provides an apparatus for obtaining an HOA coefficient, including: a obtaining module, configured to obtain location information from a virtual loudspeaker on a pre-established spherical surface, where the Rccn Ln / eznz / e / YiAi location information includes elevation information and / or azimuth information, the preset spherical surface includes M circles of longitude and N circles of latitude, an intersection between the circle of longitude and the circle of latitude is referred to as a reference point, N reference points located on a circle of longitude are arranged at equal intervals, and the M reference points located on a circle of latitude are arranged at equal intervals; and a calculation module, configured to: obtain, based on the location information and a preset reference trigonometric function table, a trigonometric function value corresponding to the location information, wherein the reference trigonometric function table includes a table of elevation trigonometric functions and / or a table of azimuth trigonometric functions,The table of trigonometric functions of elevation includes a plurality of trigonometric function values ​​corresponding to the elevation indices of a plurality of first reference points, the plurality of first reference points being reference points on a first circle of longitude, the number of the plurality of first reference points not less than [N / 4J+1, [J indicates rounding down, the first circle of longitude is one of the M circles of longitude, the table of trigonometric functions of azimuth includes a plurality of trigonometric function values ​​corresponding to the azimuth indices of a plurality of second reference points, the plurality of second reference points being reference points on a first circle of latitude, the number of the plurality of second reference points not less than [M / 4J+1,and the first latitude circle is one of the N latitude circles; and obtain a higher-order ambisonic coefficient HOA for the virtual loudspeaker based on the value of the trigonometric function corresponding to the location information. In a possible implementation, the calculation module is specifically configured to: obtain, based on the elevation information from the location information and the table of elevation trigonometric functions, a trigonometric function value corresponding to the elevation information from the location information; and / or obtain, based on the azimuth information from the location information and the table of azimuth trigonometric functions, a trigonometric function value corresponding to the azimuth information from the location information. In a possible implementation, the calculation module is specifically configured to: when the elevation information of the location information corresponds to an elevation index of a reference point from the plurality of first reference points, use, as the value of the trigonometric function corresponding to the elevation information of the location information, a trigonometric function value found in the table of trigonometric elevation functions and corresponding to the elevation index of the point of Rccn Ln / eznz / e / YiAi reference; or when the elevation information of the location information corresponds to an elevation index of a reference point of N distinct reference points of the plurality of the first reference points, convert the elevation index of the reference point of the N distinct reference points of the plurality of the first reference points into an elevation index of a reference point of the plurality of the first reference points, and use, as the trigonometric function value corresponding to the elevation information of the location information, a trigonometric function value found in the table of trigonometric functions of elevation and corresponding to the elevation index of the reference point;or when the elevation information of the location information does not correspond to an elevation index of any reference point, obtain, based on the elevation information of the location information, elevation information of a reference point corresponding to the elevation information of the location information; and when the elevation information of the reference point corresponding to the elevation information of the location information corresponds to an elevation index of a reference point of the plurality of first reference points, use, as the value of the trigonometric function corresponding to the elevation information of the location information, a trigonometric function value found in the table of trigonometric functions of elevation and corresponding to the elevation index of the reference point;or when the elevation information of the reference point corresponding to the elevation information of the location information corresponds to an elevation index of a reference point of N distinct reference points of the plurality of the first reference points, convert the elevation index of the reference point of the N distinct reference points of the plurality of the first reference points into an elevation index of a reference point of the plurality of the first reference points, and use, as the trigonometric function value corresponding to the elevation information of the location information, a trigonometric function value found in the table of trigonometric functions of elevation and corresponding to the elevation index of the reference point. In a possible implementation, the calculation module is specifically configured to: when the azimuth information of the location information corresponds to an azimuth index of a reference point from the plurality of second reference points, use, as the value of the trigonometric function corresponding to the azimuth information of the location information, a trigonometric function value found in the table of azimuth trigonometric functions and corresponding to the azimuth index of the reference point; or when the azimuth information of the location information corresponds to an azimuth index of a reference point from M distinct reference points of the plurality Rccn Ln / eznz / e / YiAi of second reference points, convert the reference point azimuth index of the M distinct reference points of the plurality of second reference points into an azimuth index of a reference point of the plurality of second reference points, and use, as the trigonometric function value corresponding to the azimuth information of the location information, a trigonometric function value found in the table of trigonometric functions of azimuth and corresponding to the reference point azimuth index; or when the azimuth information of the location information does not correspond to an azimuth index of any reference point, obtain, based on the azimuth information of the location information, azimuth information of a reference point corresponding to the azimuth information of the location information;and when the azimuth information of the reference point corresponding to the azimuth information of the location information corresponds to an azimuth index of a reference point of the plurality of second reference points, use, as the value of the trigonometric function corresponding to the azimuth information of the location information, a trigonometric function value found in the table of trigonometric azimuth functions and corresponding to the azimuth index of the reference point;or when the azimuth information of the reference point corresponding to the azimuth information of the location information corresponds to an azimuth index of a reference point of M distinct reference points of the plurality of second reference points, convert the azimuth index of the reference point of the M distinct reference points of the plurality of second reference points into an azimuth index of a reference point of the plurality of second reference points, and use, as the trigonometric function value corresponding to the azimuth information of the location information, a trigonometric function value found in the table of trigonometric azimuth functions and corresponding to the azimuth index of the reference point. In a possible implementation, the elevation information of the location information includes a location information elevation or a location information elevation index, and the azimuth information of the location information includes a location information azimuth or a location information azimuth index. In one possible implementation, the value of the trigonometric function is a value of the sinusoidal function or a value of the cosine function. In a possible implementation, when the plurality of trigonometric functions corresponding to the elevation indices of the plurality of first reference points are sinusoidal function values, a sinusoidal function value corresponding to an elevation index of a iavoprimer reference point satisfies the following formula (1): Rccn Ln / eznz / B / YiAi sin _table_N(i) = sin x (1), where i=0,1, and N', N'=[N / 4], yr¡ indicates a radius of the first circle of length; or when the plurality of trigonometric functions corresponding to the elevation indices of the plurality of first reference points are cosine function values, a cosine function value corresponding to an elevation index of a iavoprimer reference point satisfies the following formula (2): eos _table_N(i) = eos xi) (2), where i=0,1, ..., and N', N'=[N / 4J, yr¡ indicates a radius of the first circle of length. In a possible implementation, when the plurality of trigonometric functions corresponding to the azimuth indices of the plurality of second reference points are sinusoidal function values, a sinusoidal function value corresponding to an azimuth index of a second reference point satisfies the following formula (3): sin _table_M(j) = sin xf) (3), where j=0, 1, ..., and M', M'=[M / 4], and η indicates a radius of the first circle of latitude; or when the plurality of trigonometric functions corresponding to the azimuth indices of the plurality of second reference points are cosine function values, a cosine function value corresponding to an azimuth index of a second reference point satisfies the following formula (4): eos _table_M(j) = eos xf) (4), where j=0,1, ..., and M', M'=[M / 4], and η indicates a radius of the first circle of latitude. In a possible implementation, the elevation φ and the elevation index <p' cumplen con la siguiente fórmula (5): φ' = round (—-—) (5), where v\2,τ?',χN�7v' r¡ indicates a radius of the first circle of length, and round() indicates the rounding. In a possible implementation, the azimuth Θ and the azimuth index θ' comply with the following formula (6): (Θ \ ------- (6), where 2nrjXMjv' η indicates a radius of the first circle of latitude, and round() indicates rounding. In the table of trigonometric elevation functions in which a reference point location is represented in the form of an elevation index, assuming N=1024, Rccn Ln / eznz / e / YiAi The table of trigonometric elevation functions may include values ​​of trigonometric functions, for example, sin[0] to sin

[256] , which correspond respectively to elevation indices of 257 reference points. Similarly, in the table of trigonometric azimuth functions where a Rccn Ln / eznz / e / YiAi The location of a reference point is represented in the form of an azimuth index, assuming M=1024, the table of trigonometric azimuth functions may also include trigonometric function values, for example, sin[0] to sin

[256] , which correspond respectively to azimuth indices of 257 reference points. In a possible implementation, when M^N, the value of the trigonometric function corresponding to the elevation information of the location information satisfies the following formulas: s¡n((p)=s¡n_table_N(cp') s¡n(íp)=s¡n_table_N(N / 2—φ') 5ίη(φ)=-5ίη_ί3όΙβ_Ν(φ'-Ν / 2) 5ίη(φ)=-3ίη_ί3όΙθ_Ν(Ν-φ') cos(cp)=sin_table_N(N / 4—φ') cos( <p)=—sin_table_N(tp'—N / 4) cos(<p)=-sin_table_N(3N / 4-<p') cos((p)=sin_table_N((p'-3N / 4) φ'<[Ν / 4] [Ν / 4]<φ'<[Ν / 2] ίΝ / 2]<φ'<[3Ν / 4] [3Ν / 4]<φ'<Ν q> '<[N / 4J [N / 4]<φ'<[N / 2] [N / 2]<φ'<[3N / 4] |3N / 4]<φ'<N, where φ indicates the elevation information of the location information, or φ indicates the elevation information of the reference point corresponding to the elevation information of the location information, and sin_table_N() indicates the table of trigonometric elevation functions; and When M^N, the value of the trigonometric function corresponding to the azimuth information of the location information satisfies the following formulas: sin(0)=sin_table_M(0') sin(0)=sin_table_M(M / 2-0') sin(0)=—sin_table_M(0'—M / 2) sin(0)=-sin_table_M(M-0') cos(0)=sin_table_M(M / 4-0') cos(0)=-sin_table_M(0'-M / 4) cos(0)=-sin_table_M(3M / 4-0') cos(0)=sin_table_M(0'-3M / 4) 0'<[M / 4J LM / 4J<0' <LM / 2J LM / 2J<0'<L3M / 4J |3M / 4J<0'<M 0'<[M / 4J LM / 4J<0' <LM / 2J LM / 2J<0'<L3M / 4J |3M / 4J<0'<M, donde indica la información de azimut de la información de ubicación, o 0 indica la información de azimut del punto de referencia correspondiente a la información de azimut de la información de ubicación, y sin_table_M() indica la tabla de funciones trigonométricas de azimut; either When M=N, the value of the trigonometric function corresponding to the elevation information of the location information satisfies the following formulas: Rccn Ln / eznz / e / YiAi sin((p)=sin_table((p') sin((p)=s¡n_table(N / 2—φ') sin(tp)=—sin_table(cp'—N / 2) sin(tp)=—sin_table(N—φ') cos( <p)=sin_table(N / 4-tp') cos(cp)=-sin_table((p'-N / 4) cos(<p)=-sin_table(3N / 4-(p') cos(<p)=sin_table((p'-3N / 4) tp'<[N / 4J [N / 4]<φ'<ίN / 2] [N / 2J<(p'<|3N / 4J [3N / 4]<φ'<N φ'<[N / 4] [N / 4]<φ'<ίN / 2] |.Ν / 2]<φ'<|3Ν / 4] |3N / 4J<(p' <N, donde φ indica la información de elevación de la información de ubicación, o φ indica la información de elevación del punto de referencia correspondiente a la información de elevación de la información de ubicación, y sin_table_N() indica la tabla de funciones trigonométricas de elevación; y cuando M=N, el valor de la función trigonométrica correspondiente a la información de azimut de la información de ubicación cumple con las siguientes fórmulas: sin(0)=sin_table(0') sin(0)=sin_table(N / 2-6') sin(0)=-sin_table(0'-N / 2) sin(0)=-sin_table(N-0') cos(0)=sin_table(N / 4-0') cos(0)=-sin_table(0'-N / 4) cos(0)=-sin_table(3N / 4-0') cos(0)=sin_table(0'-3N / 4) 0'<|N / 4J LN / 4J <e'<LN / 2J LN / 2J<e'<|3N / 4J |3N / 4]<0'<N 0'<[N / 4] LN / 4J<0' <LN / 2J LN / 2J<0'<L3N / 4J [3N / 4J<0'<N, donde indica la información de azimut de la información de ubicación, o 0 indica la información de azimut del punto de referencia correspondiente a la información de azimut de la información de ubicación, y sin_table_N() indica la tabla de funciones trigonométricas de elevación; When M^N, Μ=K1χN and K1 >2, the value of the trigonometric function corresponding to the azimuth information of the location information satisfies the following formulas: sin(0)=sin_table_M(0') sin(0)=sin_table_M(M / 2-0') sin(0)=—sin_table_M(0'—M / 2) 0'<[M / 4] LM / 4J<0' <LM / 2J LM / 2J<0' <L3M / 4J s¡n(0)=—sin_table_M(M—θ') cos(0)=sin_table_M(M / 4-0') cos(9)=-sin_table_M(6'-M / 4) cos(9)=-sin_table_M(3M / 4-9') cos(0)=sin_table_M(0'-3M / 4) |3Μ / 4]<Θ'<Μ θ'<[Μ / 4] [Μ / 4]<θ'<[Μ / 2] |Μ / 2]<θ'<[3Μ / 4] |3M / 4J<0'<M, donde θ indica la información de azimut de la información de ubicación, o θ indica la información de azimut del punto de referencia correspondiente a la información de azimut de la información de ubicación, y sin_table_M() indica la tabla de funciones trigonométricas de azimut; y cuando M^N, Μ=Κ1χΝ y K1 > 2. The value of the trigonometric function corresponding to the elevation information of the location information complies with the following formulas: sin((p)=sin_table_M(K1 χφ') sin((p)=sin_table_M(M / 2-K1 χφ') sin((p)=-sin_table_M(K1 χφ'-Μ / 2) sin((p)=-sin_table_M(M-K1 χφ') cos( <p)=s¡n_table_M(M / 4-K1 χφ') cos(<p)=-sin_table_M(K1 χφ'-Μ / 4) cos(<p)=-sin_table_M(3M / 4-K1 χφ') cos(<p)=sin_table_M(K1 χφ'-3Μ / 4) Κ1χφ'<[Μ / 4] |Μ / 4]<Κ1χφ'<|Μ / 2] [Μ / 2]<Κ1χφ'<[3Μ / 4] |3Μ / 4]<Κ1 χφ'<Μ Κ1 χφ'<[M / 4] [Μ / 4]<Κ1χφ'<[Μ / 2] [Μ / 2]<Κ1χφ'<[3Μ / 4] [3M / 4J <K1 χφ’<Μ, donde φ indica la información de elevación de la información de ubicación, o φ indica la información de elevación del punto de referencia correspondiente a la información de elevación de la información de ubicación, y sin_table_M() indica la tabla de funciones trigonométricas de azimut; When M#N, N=K1χN and K2>2, the value of the trigonometric function corresponding to the elevation information of the location information satisfies the following formulas: sin(íp)=sin_table_N(cp') q>'<[N / 4J sin(íp)=sin_table_N(N / 2—φ') [Ν / 4]<φ'<[Ν / 2] sin(íp)=—sin_table_N(tp'—N / 2) |Ν / 2]<φ'<|3Ν / 4] sin((p)=—sin_table_N(N—φ') |3Ν / 4]<φ'<Ν cos( <p)=sin_table_N(N / 4-q)') cp'<[N / 4J cos(<p)=-sin_table_N((p'-N / 4) [Ν / 4]<φ'<[Ν / 2] cos(cp)=-sin_table_N(3N / 4-<p') |Ν / 2]<φ'<|3Ν / 4] cos(<p)=sin_table_N(q)'-3N / 4) [3N / 4J<tp'<N, donde φ indica la información de elevación de la información de ubicación, o φ indica la Elevation information of the reference point corresponding to the elevation information Rccn Ln / eznz / e / YiAi 22 of the location information, and sin_table_N() indicates the table of trigonometric elevation functions; and when IWN, N=K1*N and K2>2, the value of the trigonometric function corresponding to the azimuth information of the location information satisfies the following formulas: 5 sin(0)=sin_table_N(K2x0') K2x0'<[N / 4] sin(0)=sin_table_N(N / 2-K2x0') [N / 4] <K2x0'<LN / 2] s¡n(0)=-s¡n_table_N(K2x0'-N / 2) [N / 2]<K2x0'<L3N / 4] sin(0)=-sin_table_N(N-K2x0') L3N / 4]<K2x0’<N cos(0)=sin_table_N(N / 4-K2x0') K2x0'<[N / 4] 10 cos(0)=-sin_table_N(K2x0'-N / 4) [N / 4]<K2x0'<[N / 2] cos(0)=-sin_table_N(3N / 4-K2x0') LN / 2]<K2x0'<L3N / 4] cos(0)=sin_table_N(K2x0'-3N / 4) [3N / 4]<K2x0'<N, donde 0 indica la información de azimut de la información de ubicación, o 0 indica la información de azimut del punto de referencia correspondiente a la información de azimut de la información 15 de ubicación, y sin_table_N() indica la tabla de funciones trigonométricas de elevación;0 when M^N, the value of the trigonometric function corresponding to the elevation information of the location information satisfies the following formulas: sin(0)=cos_table_N(N / 4-0') 0'<[N / 4] 20 sin(0)=cos_table_N(0'-N / 4) LN / 4]<0' <LN / 2] sin(0)=-cos_table_N(3N / 4-0') [N / 2]<0'<L3N / 4] sin(0)=-cos_table_N(0'-3N / 4) [3N / 4]<0'<N cos(0)=cos_table_N(0') 0'<[N / 4] cos(0)=-cos_table_N(N / 2-0') [N / 4]<0'<LN / 2] 25 cos(0)=-cos_table_N(0'-N / 2) [N / 2]<0'<L3N / 4] cos(0)=cos_table_N(N-0') |3N / 4J<0'<N, donde φ indica la información de elevación de la información de ubicación, o φ indica la información de elevación del punto de referencia correspondiente a la información de elevación de la información de ubicación, y cos_table_N() indica la tabla de funciones trigonométricas de 30 elevación;and when M^N, the value of the trigonometric function corresponding to the azimuth information of the location information satisfies the following formulas: sin(0)=cos_table_M(M / 4-0') 0'<[M / 4J sin(0)=cos_table_M(0'-M / 4) [M / 4]<0'<[M / 2J 35 sin(0)=-cos_table_M(3M / 4-0') [M / 2]<0' <L3M / 4]; Rccn Ln / eznz / Β / γΐΛΐ sin(0)=—cos_table_M(0'—3Μ / 4) cos(0)=cos_table_M(6') cos(9)=-cos_table_M(M / 2-9') cos(9)=-cos_table_M(6'-M / 2) cos(0)=cos_table_M(M-6') [3Μ / 4]<Θ'<Μ θ'<[Μ / 4] [Μ / 4]<θ'<[Μ / 2] [M / 2]<6'<|3M / 4J |3Μ / 4]<θ'<Μ, where Accn Ln / eznz / e / YiAi θ indicates the azimuth information of the location information, or θ indicates the azimuth information of the reference point corresponding to the azimuth information of the location information, and cos_table_M() indicates the azimuth trigonometric function table. According to a third aspect, this application provides an audio processing device, which includes: one or more processors; and a memory, configured to store one or more programs, where when one or more programs are executed by one or more processors, one or more processors are enabled to implement the method according to any of the implementations of the first aspect. According to a fourth aspect, this application provides a computer-readable storage medium that includes a computer program. When the computer program product is executed on a computer, the computer is enabled to perform the method according to any of the above aspects. BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a diagram of an example structure of an audio playback system according to this application; FIGURE 2 is a diagram of an example structure of an audio decoding system 10 according to this application; FIGURE 3 is a diagram of an example structure of an HOA coding apparatus according to this application; FIGURE 4 is an example flowchart of a method for obtaining an HOA coefficient in accordance with this request; FIGURE 5 is an example schematic diagram of a pre-established spherical surface according to this request; FIGURE 6 is an example schematic diagram of location information in accordance with this request; and FIGURE 7 is a diagram of an example structure of an apparatus for obtaining an HOA coefficient in accordance with this request. DETAILED DESCRIPTION OF THE INVENTION To clarify the objectives, technical solutions, and advantages of this application, the technical solutions are described below with reference to the accompanying drawings. The described embodiments are not all, but some, of the embodiments covered by this application. All other embodiments obtained by a person skilled in the art based on the embodiments of this application, without creative effort, will fall within the scope of protection of this application. In the specification, claims, and accompanying drawings of this application, the terms “first,” “second,” and the like are for distinction and description purposes only and shall not be construed as indicating or implying materiality or order. Furthermore, the terms “include,” “comprising,” and any variant thereof are intended to encompass non-exclusive inclusion, for example, the inclusion of a series of steps or units. A method, system, product, or device is not necessarily limited to clearly enumerated steps or units but may include other steps or units that are not clearly enumerated and that are inherent in the process, method, product, or device. It should be understood that, in this application, “at least one” means one or more, and “plural of” means two or more. The term “and / or” describes an associative relationship between associated objects and indicates that three relationships are possible. For example, “A and / or B” can indicate the following three cases: Only A exists, only B exists, and A and B exist, where A and B can be singular or plural. The character “or” normally indicates an “or” relationship between the associated objects. “At least one of the following” or a similar expression thereof means any combination of these elements, including a single element or any combination of a plurality of elements. For example, “at least one of a, b, oc” can indicate a, b, c, “ayb”, “ayc”, “byc”, or “a, b, and c”, where a, b, and c can be singular or plural. Two values ​​connected by the character “or” normally indicate a range of values, and the range of values ​​includes the two values ​​connected by the character “or”. The terms related to this application are described below. Audio frame: Audio data is in stream form. In real-world applications, to facilitate audio processing and transmission, audio data within a specific duration is typically selected as an audio frame. This duration is known as the "sampling time," and its value can be determined according to the requirements of a specific codec and application. For example, the duration ranges from 2.5 ms to 60 ms, where ms stands for milliseconds. Audio signal: An audio signal is a carrier of information about changes in the frequency and amplitude of a regular sound wave, including voice, music, and sound effects. Audio is an analog signal that changes continuously and can be represented by a continuous curve known as a sound wave. A digital signal generated from audio through analog-to-digital conversion or by a computer is a signal of Rccn Ln / eznz / e / YiAi audio. A sound wave has three important parameters: frequency, amplitude, and phase. These determine the characteristics of an audio signal. The following describes a system architecture to which this request applies. Figure 1 is a diagram of an example audio playback system structure according to this application. As shown in Figure 1, the audio playback system includes an audio sending device and an audio receiving device. The audio sending device includes a device that can encode audio and send an audio bitstream, for example, a mobile phone, a computer (a laptop, a desktop computer, or similar), or a tablet (a portable tablet, a vehicle-mounted tablet, or similar). The audio receiving device includes a device that can receive an audio bitstream, decode the audio bitstream, and play back the audio, for example, a true wireless headset, a standard wireless earbud, an audio device, a smartwatch, or smart glasses. A Bluetooth connection can be established between the audio sending device and the audio receiving device, allowing voice and music to be transmitted between them. General examples of audio sending and receiving devices include a mobile phone and true wireless earbuds (TWS), wireless over-ear headphones, or wireless neckband headphones; or a mobile phone and another terminal device (e.g., a smart speaker, smartwatch, smart glasses, or a vehicle-mounted speaker).Optionally, examples of the audio sending device and audio receiving device can be alternatively a tablet, a laptop or a desktop computer, and a TWS headset, a wireless head-mounted hearing aid, a wireless neckband hearing aid or other terminal device (e.g. a smart speaker, a smartwatch, smart glasses, or a vehicle-mounted speaker). It should be noted that, in addition to Bluetooth, the audio sending and receiving devices can also connect via other communication methods, such as Wi-Fi, a wired connection, or another wireless connection. This is not specifically limited in this application. Figure 2 is a diagram of an example structure for an audio decoding system 10 according to this application. As shown in Figure 2, the audio decoding system 10 may include a source device 12 and a destination device 14. The source device 12 may be the audio sending device in Figure 1, and the destination device 14 may be the audio receiving device in Figure 1. The source device 12 generates encoded bit sequence information. Therefore, the source device 12 may also be referred to as an encoding device. Rccn Ln / eznz / e / YiAi audio. Destination device 14 can decode the encoded bit sequence generated by source device 12. Therefore, destination device 14 can also be referred to as an audio decoding device. In this application, source device 12 and the audio encoding device can be collectively referred to as the audio sending device, and destination device 14 and the audio decoding device can be collectively referred to as the audio receiving device. The source device 12 includes an encoder 20 and may optionally include an audio source 16, an audio preprocessor 18, and a communication interface 22. Audio Source 16 may include or be any type of audio capture device, for example, an audio capture device for capturing real-world sound; and / or any type of audio generation device, for example, a computer audio processor, or any type of device for obtaining and / or providing real-world audio, computer animation audio (for example, screen content or virtual reality (VR) audio); and / or any combination thereof (for example, augmented reality (AR) audio, mixed reality (RM) audio, and / or extended reality (XR) audio). Audio Source 16 may be a microphone for capturing audio or a memory for storing audio. Audio Source 16 may include any type of interface (internal or external) for storing previously captured or generated audio and / or obtaining or receiving audio.When audio source 16 is a microphone, it could be, for example, a local audio capture device or an audio capture device integrated into the source device. When audio source 16 is memory, it could be, for example, local memory or memory integrated into the source device. When audio source 16 includes an interface, the interface could be, for example, an external interface for receiving audio from an external audio source. The external audio source could be, for example, an external audio capture device, such as a speaker, microphone, external memory, or an external audio generation device. The external audio generation device could be, for example, an audio processor in an external computer, a computer, or a server.The interface can be any type of interface, for example, a wired or wireless interface or an optical interface, in accordance with any proprietary or standardized interface protocol. In this application, audio source 16 obtains a current scene audio signal. The current scene audio signal is an audio signal obtained by capturing a sound field at a location where a microphone is positioned in space, and it can also be referred to as the audio signal in a raw scene. For example, the current scene audio signal could be an audio signal obtained using higher-order ambisonic technology. Rccn Ln / eznz / e / YiAi ambisonics, HOA). Audio source 16 obtains an encoded HOA signal. For example, the HOA signal can be obtained by using an actual capture device, or the HOA signal can be obtained by synthesizing an artificial audio object. Optionally, the HOA signal to be encoded can be a time-domain HOA signal or a frequency-domain HOA signal. The Audio Preprocessor 18 is configured to receive a raw audio signal and preprocess it to produce a preprocessed audio signal. For example, the preprocessing performed by the Audio Preprocessor 18 might include noise shaping or noise removal. Encoder 20 is configured to receive the preprocessed audio signal and process the preprocessed audio signal to provide encoded bit sequence information. The communication interface 22 of the source device 12 can be configured to receive bit sequence information and send the bit sequence to the destination device 14 through a communication channel 13. The communication channel 13 is, for example, a direct wired or wireless connection, any type of network, such as a wired or wireless network or any combination thereof, or any type of private or public network or any combination thereof. The target device 14 includes a decoder 30 and may optionally include a communication interface 28, an audio post-processor 32 and a playback device 34. The communication interface 28 of the destination device 14 is configured to directly receive bit sequence information from the source device 12 and provide the bit sequence information for the decoder 30. The communication interface 22 and the communication interface 28 can be configured to send or receive bit sequence information through the communication channel 13 between the source device 12 and the destination device 14. Communication interface 22 and communication interface 28 can be configured as a one-way communication interface, indicated by an arrow in FIGURE 2, corresponding to communication channel 13 and directed from source device 12 to destination device 14, or as a two-way communication interface, and can be configured to: send and receive messages or the like to establish a connection, determine and exchange any other information related to a communication link and / or data transmission, such as encoded audio data, and the like. Decoder 30 is configured to receive bit sequence information and decode the bit sequence information to obtain decoded audio data. The audio post-processor 32 is configured to post-process the audio data Rccn Ln / eznz / e / YiAi are decoded to obtain post-processed audio data. The post-processing performed by the audio post-processor 32 may include, for example, trimming or resampling. The playback device 34 is configured to receive post-processed audio data and play it back to a user or listener. The playback device 34 can be or include any type of player for reproducing reconstructed audio, such as a built-in or external speaker. For example, the speaker might include a loudspeaker or an acoustic device. Figure 3 is a diagram of an example structure of an HOA encoding apparatus according to this application. As shown in Figure 3, the HOA encoding apparatus can be used in encoder 20 in audio decoding system 10. The HOA encoding apparatus includes a virtual speaker configuration unit, an encoding analysis unit, a virtual speaker set generation unit, a virtual speaker selection unit, a virtual speaker signal generation unit, and a core encoder processing unit. The virtual speaker configuration unit is configured to set up a virtual speaker based on the encoder configuration information, in order to obtain a virtual speaker configuration parameter. The encoder configuration information includes, but is not limited to, an HOA order, an encoding bit rate, and user-defined information. The virtual speaker configuration parameter includes, but is not limited to, the number of virtual speakers, the virtual speaker's HOA order, and similar information. The virtual speaker configuration parameter emitted by the virtual speaker configuration unit is used as input to the virtual speaker set generation unit. The encoding analysis unit is configured to perform encoding analysis on a HOA signal to be encoded, for example, analyzing the sound field distribution of the HOA signal to be encoded, including characteristics such as the number of sound sources, directivity, and dispersion of the HOA signal to be encoded. The sound field distribution is used as one of the determining factors in selecting a target virtual loudspeaker. Alternatively, in this application, the HOA encoding device cannot include the encoding analysis unit. Specifically, the HOA encoding device may not analyze an input signal. In this case, the selection of a target virtual loudspeaker is determined by a default setting. The HOA encoding device obtains the HOA signal to be encoded. For example, an HOA signal recorded from a real-world capture device or an HOA signal obtained through the synthesis of an artificial audio object can be used as input for the encoder, and the Rccn Ln / eznz / e / YiAi HOA signal to be encoded entered into the encoder can be a time domain HOA signal or a frequency domain HOA signal. The virtual speaker generation unit is configured to generate a set of virtual speakers. The virtual speaker set can include a plurality of virtual speakers, and the virtual speaker in the virtual speaker set can also be referred to as a "candidate virtual speaker". The virtual speaker array generation unit generates a HOA coefficient for a specified candidate virtual speaker. The coordinates (i.e., location information) of the candidate virtual speaker and an HOA order of the candidate virtual speaker provided by the virtual speaker configuration unit are used to generate the HOA coefficient for the candidate virtual speaker. One method for determining the coordinates of the candidate virtual speaker includes, but is not limited to, generating K virtual speakers according to an equidistance rule, generating K non-uniformly distributed candidate virtual speakers according to an auditory perception principle, and generating coordinates of uniformly distributed candidate virtual speakers based on a number of candidate virtual speakers. Next, an HOA coefficient is generated for a candidate virtual loudspeaker. In the present, an HOA coefficient for each virtual speaker is obtained and represented by using a method to obtain an HOA coefficient in this application, to obtain the set of virtual speakers. The HOA coefficient for the candidate virtual loudspeaker emitted by the virtual loudspeaker array generation unit is entered for the virtual loudspeaker selection unit. The virtual speaker selection unit is configured to select a target virtual speaker from a plurality of candidate virtual speakers in a virtual speaker pool based on a HOA signal to be encoded. The target virtual speaker may be referred to as the virtual speaker that matches the HOA signal to be encoded, or simply as the matching virtual speaker. The virtual speaker selection unit selects a specified matching virtual speaker based on the HOA signal to be encoded and the HOA coefficient for the candidate virtual speaker emitted by the virtual speaker set generation unit. The following describes a method for selecting a matching virtual loudspeaker using an example. In one possible implementation, an inner product is calculated, through matching, between the HOA coefficient for the candidate virtual loudspeaker and the HOA signal to be encoded; a candidate virtual loudspeaker corresponding to a larger absolute value of an inner product is selected as the target virtual loudspeaker, i.e., a virtual loudspeaker Rccn Ln / eznz / e / YiAi coincident; a projection of the HOA signal to be encoded onto the candidate virtual loudspeaker is superimposed on a linear combination of the HOA coefficient for the candidate virtual loudspeaker; then a projection vector of the HOA signal to be encoded is subtracted to obtain a difference, and the above process is performed repeatedly on the difference to implement the iterative computation, where a coincident virtual loudspeaker is generated at each iteration; and the coordinates of the coincident virtual loudspeaker and an HOA coefficient for the coincident virtual loudspeaker are output. It can be understood that a plurality of coincident virtual loudspeakers are selected, and a coincident virtual loudspeaker is generated at each iteration. (Alternatively, another implementation method can be used.) The coordinates of the target virtual speaker and the HOA coefficient for the target virtual speaker emitted by the virtual speaker selection unit are used as inputs to the virtual speaker signal generation unit. The virtual loudspeaker signal generation unit is configured to generate a virtual loudspeaker signal based on the HOA signal to be encoded and the attribute information of the target virtual loudspeaker. When the attribute information is location information, the HOA coefficient for the target virtual loudspeaker is determined based on the location information of the target virtual loudspeaker. When the attribute information includes the HOA coefficient, the HOA coefficient for the target virtual loudspeaker is obtained from the attribute information. The virtual speaker signal generation unit calculates the virtual speaker signal using the HOA signal to be encoded and the HOA coefficient of the target virtual speaker. The HOA coefficient for the virtual loudspeaker is represented by a matrix A, and the HOA signal to be encoded can be obtained by a linear combination using matrix A. Furthermore, a theoretically optimal solution w, namely the virtual loudspeaker signal, can be obtained using a least-squares method. For example, the following calculation formula can be used: w = A-1X, where A-1 represents an inverse matrix of matrix A, the size of matrix A is (MxC), C is a number of target virtual loudspeakers, M is a number of channels of an HOA coefficient of order N, M=(N+1)2, already indicates the HOA coefficient for the target virtual loudspeaker, for example: Rccn Ln / eznz / e / YiAi X represents the HOA signal to be encoded, a size of the matrix X is (Mχ|_), M is the number of channels of the Nth order HOA coefficient, L is a number of time domain or frequency domain sampling points, and x represents a coefficient of the HOA signal to be encoded. The virtual speaker signal emitted by the virtual speaker signal generation unit is used as an input to the core encoder processing unit. The core encoder processing unit is configured to perform core encoder processing on the virtual speaker signal to obtain a bit sequence for transmission. The processing of the core encoder includes, but is not limited to, transformation, quantization, psychoacoustic modeling, bit sequence generation, and similar operations. This processing can be performed on either a frequency-domain or time-domain transmission channel. This is not a limitation herein. Based on the descriptions of the above modalities, this application provides a method for obtaining an HOA coefficient. Figure 4 is an example flowchart of a method for obtaining an HOA coefficient according to this application. Process 400 can be performed by either the encoder 20 or the decoder 30 in the above modalities. Specifically, the encoder 20 in the audio sending device performs audio encoding and then sends the bitstream information to the audio receiving device. The decoder 30 in the audio receiving device decodes the bitstream information to obtain a destination audio frame and then performs delivery based on the destination audio frame to obtain a sound field audio signal corresponding to one or more virtual speakers. Process 400 is described as a series of steps or operations.It should be understood that the steps or operations of process 400 can be performed in several sequences and / or simultaneously, and are not limited to an execution sequence shown in FIGURE 4. As shown in FIGURE 4, the method includes the following steps. Step 401: Obtain location information from a virtual speaker on a preset spherical surface, where location information includes elevation and / or azimuth information. The predefined spherical surface includes M circles of longitude and N circles of latitude. M and N can be equal or different. Both M and N are positive integers. For example, N is 512, 768, or 1024, and M is 512, 768, or 1024. An intersection between a circle of longitude and a circle of latitude is called a reference point. N reference points located on a circle of longitude are arranged at equal intervals, and the M reference points located on a circle of latitude are arranged at equal intervals. To ensure that the reference points can cover as many virtual speakers as possible, the following condition can be met: M × N > K, where K is the total number of virtual speakers. For example, the value of K can be 2048, 1669, 1024, or similar. For example, FIGURE 5 is an example schematic diagram of a preset spherical surface according to this request.As shown in FIGURE 5, a spatial sound field is assumed to be a spherical space with a representation center as the center of the sphere. A virtual loudspeaker can be deployed on a spherical surface of the spherical space. The spherical surface is divided by M circles of longitude and N circles of latitude. A plane containing any circle of longitude includes the spherical center. Therefore, the radii of the M circles of longitude are equal to a radius of the spherical space. A radius of only the equator between the circles of latitude is equal to the radius of the spherical space, and another circle of latitude farther from the equator has a smaller radius.In this application, because the azimuth differences between each pair of adjacent circles of longitude are equal, i.e., the M circles of longitude are evenly distributed on the spherical surface, the M reference points located on a circle of latitude are arranged at equal intervals; and because the elevation differences between each pair of adjacent circles of latitude are also equal, i.e., the N circles of latitude are evenly distributed on the spherical surface, the N reference points located on a circle of longitude are arranged at equal intervals.Consequently, because N reference points located on a circle of longitude are arranged at equal intervals, the elevation differences between all adjacent reference points located on a circle of longitude are equal; and because M reference points located on a circle of latitude are arranged at equal intervals, the azimuth differences between all adjacent reference points located on a circle of latitude are equal. Rccn Ln / eznz / e / YiAi The virtual speaker can be any virtual speaker configured for sound reproduction. The location information for the virtual speaker on the spherical surface includes elevation and / or azimuth information. For example, FIGURE 6 is a schematic diagram illustrating the location information as per this application.As shown in FIGURE 6, an included angle between a pre-established horizontal plane (for example, a plane in which the equator lies, a plane in which the south pole lies, or a plane in which the north pole lies, where the plane in which the south pole lies is perpendicular to a connecting line between the south pole and the north pole, and the plane in which the north pole lies is perpendicular to the connecting line between the south pole and the north pole) and a connecting line between a virtual speaker location and a center of the earth is the virtual speaker elevation information; and an included angle between a specified initial direction and a projection, in the horizontal plane, of the connecting line between the virtual speaker location and the center of the earth is the azimuth information of the virtual speaker location information. Optionally, the elevation information of the virtual speaker location information may be represented by an elevation or an elevation index, and similarly, the azimuth information of the virtual speaker location information may be represented by an azimuth or an azimuth index. For example, there are N reference points on a longitude circle. These N reference points are arranged at equal intervals, and the difference between the elevation information of any two adjacent reference points is 2π / N. Therefore, the elevation information of each of the N reference points can be represented by a reference point elevation index; that is, the elevation information of the N reference points can be represented as 0 to N-1. If the location of the virtual speaker is exactly on a reference point, the elevation information of the virtual speaker can be represented by the above elevation index. Similarly, there are M reference points on a latitude circle. These M reference points are arranged at equal intervals, and the difference between the azimuth information of any two adjacent reference points is 2π / M.Therefore, the azimuth information of each of the M reference points can be represented by an azimuth index of the reference point; that is, the azimuth information of the M reference points can be represented as 0 to M-1. If the location of the virtual speaker is exactly on a reference point, the azimuth information of the virtual speaker can be represented by the above azimuth index. It can be learned that an elevation index and an elevation of a reference point are in a one-to-one correspondence, and an azimuth index and an azimuth of a reference point are in a one-to-one correspondence. However, if the location of the virtual speaker is not... Rccn Ln / eznz / e / YiAi is located at a reference point, but a specific reference point whose elevation and / or azimuth index will be used to represent the virtual speaker's location information cannot be determined. Therefore, the virtual speaker's location information may be represented by an elevation and / or an azimuth. It should be understood that even if the virtual speaker's location is exactly at a reference point, the virtual speaker's location information may also be represented by an elevation and / or an azimuth. This is not specifically limited herein. Step 402: Obtain, based on location information and a pre-established table of reference trigonometric functions, a trigonometric function value corresponding to the location information. The reference trigonometric functions table includes a table of elevation trigonometric functions and / or a table of azimuth trigonometric functions. The table of trigonometric functions of elevation includes a plurality of trigonometric function values ​​corresponding to the elevation indices of a plurality of first reference points. The plurality of first reference points are reference points on a first circle of longitude. A quantity of the plurality of first reference points is not less than [N / 4J+1, where [ ] indicates rounding down. The first circle of longitude is one of the M circles of longitude. In this application, any of the M circles of longitude is selected as the first circle of longitude, and the reference points (i.e., the plurality of first reference points) used to calculate the table of trigonometric elevation functions are selected from the N reference points on the first circle of longitude. According to the principle of a trigonometric function, an angle range from 0° (0) to 360° (2π) can be divided into four subranges: 0° (0) to 90° (π / 2), 90° (π / 2) to 180° (π), 180° (π) to 270° (3π / 2), and 270° (3π / 2) to 360° (2π). A trigonometric function value calculated using any of the four subranges can be extended to a trigonometric function value within the angle range of 0° to 360°. Therefore, in this application, during the selection of the plurality of first reference points, the number of the plurality of first reference points is not less than [N / 4J+1].Specifically, at least one-quarter of the N reference points on the first longitude circle are selected as the plurality of first reference points. Furthermore, the elevations of any two reference points from the selected plurality of first reference points do not overlap during the calculation of a trigonometric function value. Optionally, the elevations of the plurality of the first reference points may belong to one of the four subranges. For example, the elevations of the plurality Rccn Ln / eznz / e / YiAi of the first reference points are within the sub-range of 0° (0) to 90° (tt / 2), or the elevations of the plurality of the first reference points are within the sub-range of 90° (tt / 2) to 180° (π), or the elevations of the plurality of the first reference points are within the sub-range of 180° (π) to 270° (3π / 2), or the elevations of the plurality of the first reference points are within the sub-range of 270° (3π / 2) to 360° (2tt). Optionally, the elevations of the plurality of first reference points may belong to at least two of the four subranges. For example, an elevation of a first part of the plurality of first reference points is within the subrange of 0° (0) to 90° (tt / 2), and an elevation of a second part of the reference points is within the subrange of 90° (tt / 2) to 180° (π), where the elevations of the two parts of the reference points do not overlap during the calculation of a trigonometric function value; or an elevation of one part of the plurality of the first reference points is within the subrange of 90° (tt / 2) to 180° (π), and an elevation of another part of the reference points is within the subrange of 180° (π) to 270° (3π / 2), wherein the elevations of the two parts of the reference points do not overlap during the calculation of a trigonometric function value;or an elevation of one part of the plurality of the first reference points is within the sub-range of 180° (π) to 270° (3π / 2), and an elevation of another part of the reference points is within the sub-range of 270° (3π / 2) to 360° (2tt), wherein the elevations of the two parts of the reference points do not overlap during the calculation of a trigonometric function value; or an elevation of a first part of the plurality of the first reference points is within the sub-range of 0° (0) to 90° (tt / 2), an elevation of a second part of the reference points is within the sub-range of 90° (tt / 2) to 180° (π), and an elevation of a third part of the reference points is within the sub-range of 180° (π) to 270° (3π / 2), wherein the elevations of the three parts of the reference points do not overlap during the calculation of a trigonometric function value;or an elevation of a first part of the plurality of the first reference points is within the sub-range of 90° (tt / 2) to 180° (π), an elevation of a second part of the reference points is within the sub-range of 180° (π) to 270° (3π / 2), and an elevation of a third part of the reference points is within the sub-range of 270° (3π / 2) to 360° (2tt), wherein the elevations of the three parts of the reference points do not overlap during the calculation of a trigonometric function value;or an elevation of a first part of the plurality of the first reference points is within the sub-range of 0° (0) to 90° (tt / 2), an elevation of a second part of the reference points is within the sub-range of 90° (tt / 2) to 180° (π), an elevation of a third part of the reference points is within the sub-range of 180° (π) to 270° (3π / 2), and an elevation of a fourth part of the reference points is within the sub-range of 270° (3π / 2) to 360° (2tt), where the elevations of the four parts of; Rccn Ln / eznz / e / YiAi the reference points do not overlap during the calculation of a trigonometric function value. The lack of overlap can mean that the trigonometric function values ​​calculated using elevations belonging to different subranges are not equal. For example, there are a total of four first reference points (n1, n2, n3, and n4), where the elevation of n1 is 0, the elevation of n2 is π / 6, the elevation of n3 is π / 3, and the elevation of n4 is π / 2; or the elevation of n1 is 0, the elevation of n2 is 2 / 3π, the elevation of n3 is 4 / 3π, and the elevation of n4 is 2π. It should be noted that, in this application, a subrange to which the elevations of the plurality of first reference points belong is not specifically limited, provided that the trigonometric function values ​​of the elevations of the plurality of first reference points can cover the trigonometric function values ​​at all angles within one of the subranges. Consequently, a range of values ​​for the elevation of the location information is from 0 to 2tt. As described above, the plurality of the first reference points can alternatively be identified by their respective elevation indices, and conversion can be made between an elevation of the first reference point and an elevation difference based on an elevation index and an elevation difference between adjacent circles of latitude. In this application, the plurality of trigonometric functions corresponding to the elevation indices of the plurality of first reference points can be sinusoidal function values ​​or cosine function values. Optionally, a sinusoidal function value corresponding to a first reference point elevation index satisfies the following formula (1): sin _table_N(i) = sin x (1), where i=0,1,..., and N', N'=[N / 4], and r¡ indicates a radius of the first circle of length. Optionally, the values ​​of i can be discontinuous in a range from 0 to [N / 4J—1]. For example, i=0, 2, 4, 5, 9, ..., and N'. Optionally, a cosine function value corresponding to an elevation index of a first reference point satisfies the following formula (2): eos _table_N(i) = eos x 0 (2), where i=0,1, ..., and N', N'=[N / 4J, yr¡ indicates a radius of the first circle of length. The table of trigonometric azimuth functions includes a plurality of trigonometric function values ​​corresponding to azimuth indices of a plurality of seconds Rccn Ln / eznz / B / YiAi reference points. The plurality of second reference points are reference points on a first circle of latitude. A quantity of the plurality of second reference points is not less than |M / 4J+1, where [J indicates rounding down. The first circle of latitude is one of the N circles of latitude. In this application, any of the N circles of latitude is selected as the first circle of latitude, and the reference points (i.e., the plurality of the second reference points) used to calculate the table of trigonometric azimuth functions are selected from the M reference points on the first circle of latitude. Similarly, according to the principle of a trigonometric function, an angle range from 0° (0) to 360° (2π) can be divided into four subranges: 0° (0) to 90° (π / 2), 90° (π / 2) to 180° (π), 180° (π) to 270° (3π / 2), and 270° (3π / 2) to 360° (2π). A trigonometric function value calculated using any of the four subranges can be extended to a trigonometric function value within the angle range of 0° (0) to 360° (2π). Therefore, in this application, during the selection of the plurality of second reference points, the number of the plurality of second reference points is not less than [M / 4J+1].Specifically, at least a quarter of the M reference points in the first latitude circle are selected as the plurality of second reference points. Furthermore, the azimuths of any two reference points from the selected plurality of second reference points do not overlap during the calculation of a trigonometric function value. Optionally, the azimuths of the plurality of second reference points can belong to one of four subranges. For example, the azimuths of the plurality of second reference points are within the subrange of 0° (0) to 90° (π / 2), or the azimuths of the plurality of second reference points are within the subrange of 90° (π / 2) to 180° (π), or the azimuths of the plurality of second reference points are within the subrange of 180° (π) to 270° (3π / 2), or the azimuths of the plurality of second reference points are within the subrange of 270° (3π / 2) to 360° (2π). Optionally, the azimuths of the plurality of second reference points may belong to at least two of the four subranges. For example, an azimuth of a first part of the plurality of second reference points is within the subrange of 0° (0) to 90° (π / 2), and an azimuth of a second part of the reference points is within the subrange of 90° (π / 2) to 180° (π), where the azimuths of the two parts of the reference points do not overlap during the calculation of a trigonometric function value; or an azimuth of a first part of the plurality of second reference points is within the sub-range of 90° (π / 2) to 180° (π), and an azimuth of a second part of the reference points is within the sub-range of 180° (π) to 270° (3π / 2), where the azimuths of the two parts of the points of Rccn Ln / eznz / e / YiAi reference do not overlap during the calculation of a trigonometric function value; or an azimuth of a first part of the plurality of second reference points is within the sub-range of 180° (π) to 270° (3π / 2), and an azimuth of a second part of the reference points is within the sub-range of 270° (3π / 2) to 360° (2π), wherein the azimuths of the two parts of the reference points do not overlap during the calculation of a trigonometric function value; or an azimuth of a first part of the plurality of second reference points is within the subrange of 0° (0) to 90° (π / 2), an azimuth of a second part of the reference points is within the subrange of 90° (π / 2) to 180° (π), and an azimuth of a third part of the reference points is within the subrange of 180° (π) to 270° (3π / 2), wherein the azimuths of the three parts of the reference points do not overlap during the calculation of a trigonometric function value;or an azimuth of a first part of the plurality of second reference points is within the subrange of 90° (π / 2) to 180° (π), an azimuth of a second part of the reference points is within the subrange of 180° (π) to 270° (3π / 2), and an azimuth of a third part of the reference points is within the subrange of 270° (3π / 2) to 360° (2π), wherein the azimuths of the three parts of the reference points do not overlap during the calculation of a trigonometric function value;or an azimuth of a first part of the plurality of second reference points is within the sub-range of 0° (0) to 90° (π / 2), an azimuth of a second part of the reference points is within the sub-range of 90° (π / 2) to 180° (π), an azimuth of a third part of the reference points is within the sub-range of 180° (π) to 270° (3π / 2), and an azimuth of a fourth part of the reference points is within the sub-range of 270° (3π / 2) to 360° (2π), wherein the azimuths of the four parts of reference points do not overlap during the calculation of a trigonometric function value. The lack of overlap can mean that the trigonometric function values ​​calculated using azimuths belonging to different subranges are not equal. For example, there are a total of four second reference points (n1, n2, n3, and n4), where the azimuth of n1 is 0, the azimuth of n2 is π / 6, the azimuth of n3 is π / 3, and the azimuth of n4 is π / 2; or the azimuth of n1 is 0, the azimuth of n2 is 2 / 3π, the azimuth of n3 is 4 / 3π, and the azimuth of n4 is 2π. It should be noted that, in this application, a subrange to which the azimuths of the plurality of second reference points belong is not specifically limited, provided that the trigonometric function values ​​of the azimuths of the plurality of second reference points can cover the trigonometric function values ​​at all angles within one of the subranges. Consequently, a range of azimuth values ​​for location information is from 0 to 2π. Rccn Ln / eznz / e / YiAi As described above, the plurality of second reference points can alternatively be identified by their respective azimuth indices, and the conversion can be made between an azimuth of the second reference point and an azimuth difference based on an azimuth index and an azimuth difference between adjacent circles of longitude. In this application, the plurality of trigonometric functions corresponding to the azimuth indices of the plurality of second reference points can be sinusoidal function values ​​or cosine function values. Optionally, a sinusoidal function value corresponding to an azimuth index of a second reference point satisfies the following formula (3): sin _table_M(j) = sin x (3), where j=0,1,..., and M', M'=[M / 4J, and η indicates a radius of the first circle of latitude. Optionally, the values ​​of j can be discontinuous in a range from 0 to [N / 4J-1. For example, i=1, 3, 5, 8, 9, 10, ..., and M'. Optionally, a cosine function value corresponding to an azimuth index of a second reference point satisfies the following formula (4): eos _table_M(j) = eos xf) (4), where j=0,1, ..., and M', M'=[M / 4J, and η indicates a radius of the first circle of latitude. It should be noted that the elevation trigonometric function table and the azimuth trigonometric function table can be calculated and stored in advance, or they can be calculated and stored in real time based on the values ​​of M and N.Optionally, since both an encoder and a decoder perform framing, during the calculation of the HOA coefficient, when a value of M from a current audio frame is equal to a value of M from a previous audio frame, it may not be necessary to recalculate a table of azimuth trigonometric functions during the processing of the current frame, and a table of azimuth trigonometric functions from the previous audio frame can be used directly; and when a value of N from the current audio frame is equal to a value of N from the previous audio frame, it may not be necessary to recalculate a table of elevation trigonometric functions during the processing of the current frame, and a table of elevation trigonometric functions from the previous audio frame can be used directly. In this application, you can obtain a trigonometric function value corresponding to the elevation information of the virtual speaker's location information on the preset spherical surface based on the elevation information of the location information and the elevation trigonometric function table, and / or a trigonometric function value corresponding to the azimuth information of the virtual speaker's location information in Rccn Ln / eznz / e / YiAi The preset spherical surface can be obtained based on the azimuth information from the location information and the azimuth trigonometric function table. It can be learned that, for the location information of the virtual speaker on the preset spherical surface, the value of the trigonometric function corresponding to the location information can be obtained based on the specific content included in the location information and the specific content of the preset reference trigonometric function table. To be specific, the location information includes elevation information, and the value of the trigonometric function corresponding to the elevation information of the location information can be obtained based on the elevation information and the reference trigonometric function table (if an elevation trigonometric function table exists, the elevation trigonometric function table is used; or if an elevation trigonometric function table does not exist, the azimuth trigonometric function table is used).and the location information includes the azimuth information, and the value of the trigonometric function corresponding to the azimuth information of the location information can be obtained based on the azimuth information and the reference trigonometric function table (if there is an azimuth trigonometric function table, the azimuth trigonometric function table is used; or if there is no azimuth trigonometric function table, the elevation trigonometric function table is used). In this application, the value of the trigonometric function corresponding to the elevation information of the location information can be obtained using the following methods. 1. When the elevation information of the location information corresponds to an elevation index of a reference point from the plurality of first reference points, a trigonometric function value found in the table of trigonometric functions of elevation and corresponding to the elevation index of the reference point is used as the trigonometric function value corresponding to the elevation information of the location information. That the elevation information of the location information corresponds to an elevation index of a reference point from the plurality of first reference points indicates that the elevation corresponding to the location of the virtual speaker on the preset spherical surface is exactly equal to an elevation corresponding to an elevation index in the table of trigonometric elevation functions, or the elevation index corresponding to the location of the virtual speaker on the preset spherical surface is exactly equal to an elevation index in the table of trigonometric elevation functions. To be specific, the location of the virtual speaker on the preset spherical surface coincides with the location of a reference point selected to obtain the table of trigonometric elevation functions. Therefore, the value of the trigonometric function of the elevation information can Rccn Ln / eznz / e / YiAi can be consulted directly from the table of trigonometric functions of elevation. 2. When the elevation information of the location information corresponds to an elevation index of a reference point of N distinct reference points of the plurality of the first reference points, the elevation index of the reference point of the N distinct reference points of the plurality of the first reference points is converted into an elevation index of a reference point of the plurality of the first reference points, and a trigonometric function value found in the table of trigonometric functions of elevation and corresponding to the elevation index of the reference point is used as the trigonometric function value corresponding to the elevation information of the location information. That the elevation information of the location information corresponds to an elevation index of a reference point of N distinct reference points of the plurality of first reference points indicates that the elevation information corresponding to the location of the virtual speaker on the preset spherical surface is not equal to an elevation corresponding to any elevation index in the table of trigonometric elevation functions, but is equal to an angle corresponding to an elevation index of another reference point in the first circle of length, or the elevation index corresponding to the location of the virtual speaker on the preset spherical surface is equal to an elevation index of another reference point in the first circle of length; to be specific, the location of the virtual speaker on the preset spherical surface coincides with the location of a reference point.where the reference point is not used to obtain the table of trigonometric elevation functions, but an elevation index of the reference point has a trigonometric function correspondence with an elevation index in the table of trigonometric functions. Therefore, an elevation index of a reference point of N distinct reference points of the plurality of first reference points can be converted into an elevation index of a reference point of the plurality of first reference points according to a principle of a trigonometric function; and then a trigonometric function value corresponding to the elevation index of the reference point of the plurality of first reference points is obtained through table lookup.and the value of the trigonometric function corresponding to the elevation index of the reference point of the plurality of first reference points is used as the value of the trigonometric function corresponding to the elevation information of the location information. 3. When the elevation information of the location information does not correspond to an elevation index of any reference point, the elevation information of a reference point corresponding to the elevation information of the location information is obtained based on the elevation information of the location information; and when the Rccn Ln / eznz / e / YiAi elevation information of the reference point corresponding to the elevation information of the location information corresponds to an elevation index of a reference point of the plurality of first reference points, a trigonometric function value found in the table of trigonometric functions of elevation and corresponding to the elevation index of the reference point is used as the trigonometric function value corresponding to the elevation information of the location information;or when the elevation information of the reference point corresponding to the elevation information of the location information corresponds to an elevation index of a reference point of N distinct reference points of the plurality of the first reference points, the elevation index of the reference point of the N distinct reference points of the plurality of the first reference points becomes an elevation index of a reference point of the plurality of the first reference points, and a trigonometric function value found in the table of trigonometric functions of elevation and corresponding to the elevation index of the reference point is used as the trigonometric function value corresponding to the elevation information of the location information. The fact that the elevation information of the location information does not correspond to an elevation index of any reference point indicates that the location of the virtual speaker on the preset spherical surface is neither on a circle of longitude nor a circle of latitude. Therefore, the elevation information of the reference point corresponding to the elevation information of the location information is obtained first; and then the value of the trigonometric function corresponding to the elevation information of the reference point is obtained according to method 1 or method 2, and the value of the trigonometric function corresponding to the elevation information of the reference point is used as the value of the trigonometric function corresponding to the elevation information of the location information. Optionally, the elevation φ and the elevation index φ' satisfy the following formula (5): ω' = round (—-—) (5), where r¡ indicates a radius of the first circle of length, and round() indicates the rounding. In this application, the value of the trigonometric function corresponding to the azimuth information of the location information can be obtained using the following methods. 1. When the azimuth information of the location information corresponds to an azimuth index of a reference point of the plurality of second reference points, a trigonometric function value found in the trigonometric function table of Rccn Ln / eznz / e / YiAi azimuth and which corresponds to the azimuth index of the reference point is used as the trigonometric function value corresponding to the azimuth information of the location information. That the azimuth information of the location data corresponds to an azimuth index of a reference point from the plurality of second reference points indicates that the azimuth corresponding to the location of the virtual speaker on the preset spherical surface is exactly equal to an azimuth corresponding to an azimuth index in the azimuth trigonometric function table, or the azimuth index corresponding to the location of the virtual speaker on the preset spherical surface is exactly equal to an azimuth index in the azimuth trigonometric function table. To be specific, the location of the virtual speaker on the preset spherical surface coincides with the location of a reference point selected to obtain the azimuth trigonometric function table. Therefore, the trigonometric function value of the azimuth data can be directly obtained from the azimuth trigonometric function table. 2. When the azimuth information of the location information corresponds to an azimuth index of a reference point of M distinct reference points of the plurality of second reference points, the azimuth index of the reference point of the M distinct reference points of the plurality of second reference points is converted into an azimuth index of a reference point of the plurality of second reference points, and a trigonometric function value found in the table of azimuth trigonometric functions and corresponding to the azimuth index of the reference point is used as the trigonometric function value corresponding to the azimuth information of the location information. That the azimuth information of the location information corresponds to an azimuth index of a reference point of M distinct reference points from the plurality of second reference points indicates that the azimuth information corresponding to the location of the virtual speaker on the preset spherical surface is not equal to an elevation corresponding to any elevation index in the table of trigonometric azimuth functions, but is equal to an angle corresponding to an azimuth index of another reference point in the first circle of latitude, or the azimuth index corresponding to the location of the virtual speaker on the preset spherical surface is equal to an azimuth index of another reference point in the first circle of latitude; to be specific, the location of the virtual speaker on the preset spherical surface coincides with a location of a reference point.where the reference point is not used to obtain the table of trigonometric azimuth functions, but an azimuth index of the reference point has a trigonometric function correspondence with an azimuth index in the table of trigonometric functions. Therefore, an index of, Rccn Ln / eznz / e / YiAi The azimuth of a reference point of M distinct reference points from the plurality of second reference points can be converted into an azimuth index of a reference point from the plurality of second reference points according to a principle of a trigonometric function; and then a trigonometric function value corresponding to the azimuth index of the reference point from the plurality of second reference points is obtained through table lookup, and the trigonometric function value corresponding to the azimuth index of the reference point from the plurality of second reference points is used as the trigonometric function value corresponding to the azimuth information of the location information. 3. When the azimuth information of the location information does not correspond to an azimuth index of any reference point, the azimuth information of a reference point corresponding to the azimuth information of the location information is obtained based on the azimuth information of the location information; and when the azimuth information of the reference point corresponding to the azimuth information of the location information corresponds to an azimuth index of a reference point of the plurality of second reference points, a trigonometric function value found in the table of trigonometric azimuth functions and corresponding to the azimuth index of the reference point is used as the trigonometric function value corresponding to the azimuth information of the location information;or when the azimuth information of the reference point corresponding to the azimuth information of the location information corresponds to an azimuth index of a reference point of M distinct reference points of the plurality of second reference points, the azimuth index of the reference point of the M distinct reference points of the plurality of second reference points is converted into an azimuth index of a reference point of the plurality of second reference points, and a trigonometric function value found in the table of trigonometric azimuth functions and corresponding to the azimuth index of the reference point is used as the trigonometric function value corresponding to the azimuth information of the location information. The fact that the azimuth information of the location information does not correspond to an azimuth index of any reference point indicates that the location of the virtual speaker on the preset spherical surface is neither on a circle of longitude nor a circle of latitude. Therefore, the azimuth information of the reference point corresponding to the azimuth information of the location information is obtained first; and then the value of the trigonometric function corresponding to the azimuth information of the reference point is obtained according to method 1 or method 2, and the value of the trigonometric function corresponding to the azimuth information of the reference point is used Rccn Ln / eznz / e / YiAi as the value of the trigonometric function corresponding to the azimuth information of the location information. Optionally, the azimuth Θ and the azimuth index θ' comply with the following formula (6): / Θ \ θ' = round ------ (6), where \2nrjXMj ' ' η indicates a radius of the first circle of latitude, and round() indicates rounding. Step 403: Obtain an HOA coefficient for the virtual speaker based on the trigonometric function value corresponding to the location information. The following describes a process for generating the HOA coefficient for the virtual loudspeaker. When a sound wave travels through an ideal medium, the speed of sound is given by: k = ω / c, where the angular frequency ω is equal to 2πμ, f indicates the frequency of the sound wave, and c indicates the speed of sound. Therefore, the sound pressure p is given by the following formula (7): V2p+k2p=0 (7), where V2 is a Laplace operator. The following formula (8) can be obtained for the sound pressure p by solving formula (7) in spherical coordinates: p(r,0, <p, / c) = sLn=o(2m+ K)jmjm (Μ Σθ<η<τη,σ=±1 <?) (θ). where r indicates a radius of a sphere, θ indicates an azimuth <p, indica una elevación, k indica una velocidad de onda, s indica una amplitud de una onda planar ideal, m indica un número de secuencia de un orden HOA, jrnjm(kr) indica una función Bessel esférica, también se conoce como una función de base radial, donde la 1erj es una unidad imaginaria, (2m + no cambia con un ángulo, φ) es una función armónica esférica correspondiente a θ y φ, Y <Ps)es unafunción armónica esférica en una dirección de fuente de sonido. An ambisonic coefficient (Ambisonics) is the following: B^n= s Ym.nífis'Vs) (θ) Therefore, a general expansion form (10) for the sound pressure p can be obtained: p(r, θ, ψ, k) = Zm = ojmjm(kr) Zo <n<m,ff= + lBm,nYm,M (?) (10) Formula (9) may indicate that a sound field can expand over a spherical surface based on a spherical harmonic function, and the sound field is represented by an ambisonic coefficient. Therefore, if the ambisonic coefficient is known, the sound field can Rccn Ln / eznz / e / YiAi can be reconstructed. Equation (9) is truncated at a Navoelement, and the ambisonic coefficient is used as an approximate description of the sound field, and is therefore called the Navoorder HOA coefficient. The HOA coefficient may also be referred to as an ambisonic coefficient. The Navoorder ambisonic coefficient has a total of (N+1)2 channels. Optionally, an HOA order can range from a 2nd order to a 10th order. A spatial sound field at a time corresponding to a sampling point of an HOA signal can be reconstructed by superimposing spherical harmonic functions based on a coefficient corresponding to the sampling point. The HOA coefficient for the virtual loudspeaker can be generated according to this principle. θ5 and φ5 in Equation (9) are respectively adjusted to the location information, i.e., the azimuth and elevation, of the virtual loudspeaker.The HOA coefficient, also known as the ambisonic coefficient, for the virtual loudspeaker can be obtained based on formula (9). For example, for a 3rd-order HOA signal, assuming s=1, a 16-channel HOA coefficient corresponding to the 3rd-order HOA signal can be obtained as a function of the spherical harmonic function. <ps~). Una fórmula de cálculo para el coeficiente HOA de 16 canales correspondiente a laseñal HOA de 3erorden se muestra específicamente en la Tabla 1. Table 1 Rccn Ln / eznz / e / YiAi I m Expression in polar coordinates 0 0 1 2\[ñ 1 0 1 — 3 — eos Θ π +1 1 — 3 — sin0 cosen π -1 1 5 - — sin 0 sin <0 2 0 1 4 λ — — (3cos20 — 1) π +1 1 15 — sin Θ eos Θ eos φ π -1 1 [15 - —sin Θ eos Θ sin φ π I m Expression in polar coordinates +2 1 4 λ 15 — sin¿6 eos 2φ π -2 1 15 2 — sin Θ sin 2φ π 3 0 i F - — (5cos30 — 3 cos0) +1 1 — 21 — (5cos¿ θ — 1) sin Θ eos φ 2π -1 1 4 A — 21 — (5cos¿0 — 1) sin# sinrp +2 1 105 - ---eos Θ sin Θ eos 2φ 4 J π -2 1 105 ---eos Θ sin Θ sin 2φ π +3 1 ¡35 - — sin Θ eos 3φ -3 1 4 — 35 3 — sin Θ sin 3φ 2π Rccn Ln / eznz / e / YiAi In Table 1, θ indicates the azimuth information of the virtual loudspeaker's location information on the predefined spherical surface; φ indicates the elevation information of the virtual loudspeaker's location information on the predefined spherical surface; I indicates an HOA order, l = 0, 1, ... and N; and m indicates a direction parameter in each order, y = -1, ... and I. Based on the expression in polar coordinates in Table 1, a 16-channel HOA coefficient corresponding to a 3rd-order HOA signal of the virtual loudspeaker can be obtained from the virtual loudspeaker's location information. Furthermore, the method of the present invention can also be used to obtain an HOA coefficient of any order obtained through the expansion of a spherical harmonic function. In this application, only trigonometric function values ​​(a table of elevation trigonometric functions) of one-quarter of all reference points on a longitude circle on the pre-established spherical surface and / or trigonometric function values ​​(a table of azimuth trigonometric functions) of one-quarter of all reference points on a latitude circle on the pre-established spherical surface need to be obtained beforehand, and the trigonometric function values ​​at any angle ranging from 0° to 360° can be obtained from the trigonometric function table.Other trigonometric functions, such as a power trigonometric function and a multi-angle trigonometric function in Table 1, can be expanded using conventional technology to obtain a general expansion form that includes a sine trigonometric function and a cosine trigonometric function. Other corresponding trigonometric function values ​​can then be obtained using the method of the present invention. In this way, a significant amount of computation can be reduced at a preliminary stage. Furthermore, because the number of angles in the trigonometric function table is reduced, the amount of data that needs to be stored is also reduced accordingly, thus saving storage space. Several specific modalities are used below as examples to describe a method for obtaining trigonometric function values ​​respectively corresponding to the elevation and azimuth information of the location information, φ denotes the elevation information of the location information, or denotes the elevation information of a reference point corresponding to the location information, φ' denotes an elevation index. Θ denotes the azimuth information of the location information, or denotes the azimuth information of a reference point corresponding to the location information, θ' denotes an azimuth index. It should be noted that, in this application, elevation and azimuth information can be represented by index numbers. For example, there are N reference points on a circle of longitude, the N reference points are arranged at equal intervals, and the difference between the elevation information of any two adjacent reference points is 2π / N. Therefore, the elevation information of each of the N reference points can be represented by a reference point index number; that is, the elevation information of the N reference points can be represented as 0 to N-1. If the number of reference points for a plurality of reference points is [N / 4J+1], the elevation information for the plurality of reference points can be represented as 0 to [N / 4J].Similarly, there are M reference points on a circle of latitude, the M reference points are arranged at equal intervals, and the difference between the azimuth information of any two adjacent reference points is 2π / M. Therefore, the azimuth information of each of the M reference points can be represented by a reference point index number; that is, the azimuth information of the M reference points can be... Rccn Ln / eznz / e / YiAi can be represented as 0 to M-1. If a quantity of a plurality of second reference points is [M / 4J+1], the azimuth information of the plurality of second reference points can be represented as 0 to [M / 4J. In this application, a relationship between the elevation φ and the elevation index φ' can be obtained using formula (5), and a relationship between the azimuth θ and the azimuth index θ' can be obtained using formula (6). Mode 1 Rccn Ln / eznz / e / YiAi M#N and a table of elevation sinusoidal functions sin_table_N and a table of azimuth sinusoidal functions sin_table_M are predefined using the method in step 402. A sinusoidal function value and a corresponding cosine function value can be obtained from the elevation information of the location information according to the following rules: sin((p)=s¡n_table_N(cp') tp'<[N / 4J s¡n(íp)=s¡n_table_N(N / 2—φ') [Ν / 4]<φ'<[Ν / 2] s¡n(tp)=—sin_table_N(tp'—N / 2) [Ν / 2]<φ'<|3Ν / 4] 5ίη(φ)=-3ίη_ί3όΙθ_Ν(Ν-φ') [3Ν / 4]<φ'<Ν cos( <p)=sin_table_N(N / 4-cp') φ'<|Ν / 4] cos(<p)=-sin_table_N(q> '-N / 4) [N / 4]<φ'<[N / 2] cos( <p)=-sin_table_N(3N / 4-<p') [Ν / 2]<φ'<[3Ν / 4] cos(cp)=s¡n_t3ble_N((p'-3N / 4) |3Ν / 4]<φ'<Ν Se puede obtener un valor de función sinusoidal y un valor de función coseno corresponding to the azimuth information of the location information according to the following rules: sin(9)=s¡n_table_M(6') 9'<|M / 4J sin(9)=s¡n_table_M(M / 2-9') LM / 4J<9' <LM / 2] s¡n(9)=-s¡n_table_M(9'-M / 2) LM / 2J<9'<|3M / 4J s¡n(9)=-s¡n_table_M(M-9') |3M / 4J<9'<M cos(9)=sin_table_M(M / 4-9') 0'<|M / 4J cos(9)=-sin_table_M(9'-M / 4) LM / 4J<9'<LM / 2] cos(9)=-sin_table_M(3M / 4-9') [Μ / 2]<θ'<[3Μ / 4] cos(9)=sin_table_M(9'-3M / 4) |3M / 4]<9'<M Modalidad 2 M=N, and a table of elevation sinusoidal functions sin_table_N is predefined using the method in step 402. Because M equals N, a table of azimuth sinusoidal functions sin_table_M is the same as the table of elevation sinusoidal functions sin_table_N. In this mode, only one trigonometric function table, for example, sin_table, can be obtained. This can further reduce the amount of computation and storage required for a trigonometric function table, saving storage space. Rccn Ln / eznz / B / YiAi A sinusoidal function value and a cosine function value corresponding to the elevation information of the location information can be obtained according to the following rules: sin((p)=sin_table(cp') φ'<|N / 4] sin(íp)=sin_table(N / 2—φ') [N / 4J <cp'< |N / 2J sin(tp)=—sin_table(q)'—N / 2) [N / 2J<cp'< [3N / 4J 10 sin(<p)=—sin_table(N—φ') |3Ν / 4]<φ'<Ν cos(<p)=sin_table(N / 4-(p') <p'<|N / 4J cos(<p)=-sin_table((p'-N / 4) [N / 4J<cp'<|N / 2j cos(tp)=—sin_table(3N / 4—cp') [N / 2J<(p'<|3N / 4J cos(<p)=sin_table((p'-3N / 4) [3N / 4J<cp'<N 15 Se puede obtener un valor de función sinusoidal y un valor de función coseno correspondiente a la información de azimut de la información de ubicación de acuerdo con las siguientes reglas: sin(0)=sin_table(0') 0'<|N / 4J sin(e)=s¡n_table(N / 2-e') [N / 4J<0'<LN / 2J 20 sin(0)=—sin_table(0'—N / 2) LN / 2J<0'< |3N / 4J sin(0)=-sin_table(N-0') |3N / 4J<0'<N cos(0)=sin_table(N / 4-0') 0’<|N / 4J cos(0)=-sin_table(0'-N / 4) [Ν / 4]<θ'<[Ν / 2] cos(0)=-sin_table(3N / 4-0') [N / 2J<0'<L3N / 4j 25cos(0)=sin_table(0'-3N / 4)[3N / 4J<0' <n modalidad 3 m^n, m="K1xN," k1>2 and a table of azimuth sinusoidal functions, sin_table_M, is predefined using the method in step 402. Because M and N have a multiple relationship, a table of elevation sinusoidal functions, sin_table_N, can be obtained based on this multiple relationship in combination with a trigonometric function principle. Therefore, in this mode, only a table of trigonometric functions, for example, sin_table_M, can be obtained. This can further reduce the amount of computation and storage required for a table of trigonometric functions, thus saving storage space. A sinusoidal function value and a corresponding cosine function value can be obtained from the azimuth information of the location information according to the Rccn Ln / eznz / e / YiAi following rules: sin(0)=sin_table_M(e') 0'<[M / 4J sin(e)=sin_table_M(M / 2-6') LM / 4J<0'<LM / 2] sin(0)=-sin_table_M(0'-M / 2) LM / 2J<0'<|3M / 4J sin(0)=-sin_table_M(M-0') [3M / 4J<0'<M cos(0)=sin_table_M(M / 4-0') 0'<[M / 4J cos(0)=-sin_table_M(0'-M / 4) LM / 4J<0'<LM / 2] cos(0)=-sin_table_M(3M / 4-0') LM / 2J<0'<|3M / 4J cos(0)=sin_table_M(0'-3M / 4) [3M / 4J<0'<M Se puede obtener un valor de función sinusoidal y un valor de función coseno correspondiente a la información de elevación de la información de ubicación de acuerdo con las siguientes reglas: sin((p)=sin_table_M(K1 χφ') Κ1χφ'<[Μ / 4] sin((p)=sin_table_M(M / 2-K1 χφ') [M / 4J<K1 xq>'<lM / 2J sin((p)=-sin_table_M(K1 χφ'-Μ / 2) [M / 2J<K1 xq>'<[3M / 4J sin((p)=-sin_table_M(M-K1 χφ') [3Μ / 4)<Κ1χφ'<Μ cos(<p)=sin_table_M(M / 4-K1 χφ') Κ1χφ'<[Μ / 4] cos(cp)=-sin_table_M(K1 χφ'-Μ / 4) [M / 4J<K1 xq>'<[M / 2J cos(<p)=-sin_table_M(3M / 4-K1 χφ') LM / 2J <k1xq>'<[3M / 4J cos( <p)=sin_table_M(K1 χφ'-3Μ / 4) L3M / 4J<K1xq)'<M Mode 4 M^N, N=K2*M, K2>2, and a table of elevation sinusoidal functions, sin_table_N, are predefined using the method in step 402. Because M and N have a multiple relationship, a table of azimuth sinusoidal functions, sin_table_M, can be obtained based on this multiple relationship in combination with a trigonometric function. Therefore, in this mode, only a table of trigonometric functions, for example, sin_table_N, can be obtained. This can further reduce the amount of computation and storage required for a table of trigonometric functions, thus saving storage space. A sinusoidal function value and a corresponding cosine function value can be obtained from the elevation information of the location information according to the following rules: sin((p)=s¡n_table_N(q>') sin((p)=sin_table_N(N / 2—φ') cp'<|N / 4J LN / 4J <cp'< LN / 2J sin(tp)=—sin_table_N(tp'—N / 2) 5ίη(φ)=-5ίη_ί30Ιβ_Ν(Ν-φ') cos( <p)=sin_table_N(N / 4-tp') cos(<p)=-sin_table_N(q> '-N / 4) cos( <p)=-sin_table_N(3N / 4-<p') cos(<p)=s¡n_table_N((p'-3N / 4) Se puede obtener un valor de función sinusoidal LN / 2J<cp'<|3N / 4J L3N / 4J<cp'<N φ'<|Ν / 4] [Ν / 4]<φ'<ίΝ / 2] [Ν / 2]<φ'<ί3Ν / 4] |3Ν / 4]<φ'<Ν y un valor de función coseno Rccn Ln / eznz / e / YiAi corresponding to the azimuth information of the location information according to the following rules: sin(0)=s¡n_table_N(K2x6') sin(0)=sin_table_N(N / 2-K2x0') sin(0)=-s¡n_table_N(K2x0'-N / 2) sin(0)=-sin_table_N(N-K2xO') cos(0)=sin_table_N(N / 4-K2x0') cos(0)=-sin_table_N(K2x0'-N / 4) cos(0)=-sin_table_N(3N / 4-K2x0') cos(0)=sin_table_N(K2x0'-3N / 4) Mode 5 K2x0'<[N / 4] LN / 4] <K2x0'<LN / 2] LN / 2J<K2x0'<L3N / 4J [3N / 4]<K2x0'<N K2x0'<[N / 4] [N / 4]<K2x0'<LN / 2] LN / 2J<K2x0'<|3N / 4J [3N / 4]<K2x0'<N M#N and a table of elevation cosine functions cos_table_N and a table of azimuth cosine functions cos_table_M are predefined using the method in step 402. A sinusoidal function value and a corresponding cosine function value can be obtained from the elevation information of the location information according to the following rules: sin(0)=cos_table_N(N / 4-0') 0'<|N / 4J sin(0)=cos_table_N(0'-N / 4) LN / 4J<0' <LN / 2J sin(0)=-cos_table_N(3N / 4-0') LN / 2J<0'<|3N / 4J sin(0)=-cos_table_N(0'-3N / 4) L3N / 4J<0'<N cos(0)=cos_table_N(0') 0’<|N / 4J cos(0)=-cos_table_N(N / 2-0') LN / 4J<0'<LN / 2J cos(0)=-cos_table_N(0'-N / 2) LN / 2J<0’<L3N / 4J cos(0)=cos_table_N(N-0') |3N / 4]<0'<N Se puede obtener un valor de función sinusoidal y un valor de función coseno corresponding to the azimuth information of the location information according to the following rules: sin(0)=cos_table_M(M / 4-0') 0'<|M / 4J sin(0)=cos_table_M(0'—Μ / 4) sin(0)=-cos_table_M(3M / 4-0') sin(0)=-cos_table_M(0'-3M / 4) cos(0)=cos_table_M(0') cos(0)=-cos_table_M(M / 2-0') cos(0)=-cos_table_M(0'-M / 2) cos(0)=cos_table_M(M-0') LM / 4J<0' <LM / 2] LM / 2J<0'<|3M / 4J [3M / 4]<0'<M 0'<|M / 4J LM / 4J<0'<LM / 2] LM / 2J<0'<L3M / 4J |3M / 4J<0'<M Rccn Ln / eznz / e / YiAi Figure 7 is a diagram of an example structure of an apparatus for obtaining an HOA coefficient in accordance with this application. As shown in Figure 7, the apparatus can be used with either the encoder 20 or the decoder 30 in the above modes. The apparatus for obtaining an HOA coefficient in this mode may include a obtaining module 701 and a calculating module 702. The acquisition module 701 is configured to obtain location information from a virtual speaker on a preset spherical surface, where the location information includes elevation and / or azimuth information. The preset spherical surface includes M circles of longitude and N circles of latitude. An intersection between a circle of longitude and a circle of latitude is called a reference point. N reference points located on a circle of longitude are arranged at equal intervals, and M reference points located on a circle of latitude are arranged at equal intervals. The calculation module 702 is configured to obtain, based on the location information and a preset table of reference trigonometric functions, a trigonometric function value corresponding to the location information.where the reference trigonometric function table includes a table of elevation trigonometric functions and / or a table of azimuth trigonometric functions, the elevation trigonometric function table includes a plurality of trigonometric function values ​​corresponding to the elevation indices of a plurality of first reference points, the plurality of first reference points being reference points on a first circle of longitude, a quantity of the plurality of first reference points not less than [N / 4J+1, [ ], indicates rounding down, the first circle of longitude being one of the M circles of longitude, the azimuth trigonometric function table includes a plurality of trigonometric function values ​​corresponding to the azimuth indices of a plurality of second reference points, the plurality of second reference points being reference points on a first circle of latitude,a quantity of the plurality of second reference points is not less than [M / 4J+1, and the first circle of latitude is one of the N circles of latitude; and obtain a higher-order ambisonic HOA coefficient for the virtual loudspeaker based on the value of the trigonometric function corresponding to the location information. In a possible implementation, calculation module 702 is specifically configured to: obtain, based on the elevation information from the location information and the table of elevation trigonometric functions, a trigonometric function value corresponding to the elevation information from the location information; and / or obtain, based on the azimuth information from the location information and the table of azimuth trigonometric functions, a trigonometric function value corresponding to the azimuth information from the location information. In a possible implementation, the calculation module is specifically configured to: when the elevation information of the location information corresponds to an elevation index of a reference point from the plurality of first reference points, use, as the value of the trigonometric function corresponding to the elevation information of the location information, a trigonometric function value found in the table of trigonometric functions of elevation and which corresponds to the elevation index of the reference point;or when the elevation information of the location information corresponds to an elevation index of a reference point of N distinct reference points from the plurality of the first reference points, convert the elevation index of the reference point of the N distinct reference points from the plurality of the first reference points into an elevation index of a reference point from the plurality of the first reference points, and use, as the trigonometric function value corresponding to the elevation information of the location information, a trigonometric function value found in the table of trigonometric functions of elevation and corresponding to the elevation index of the reference point;or when the elevation information of the location information does not correspond to an elevation index of any reference point, obtain, based on the elevation information of the location information, elevation information of a reference point corresponding to the elevation information of the location information; and when the elevation information of the reference point corresponding to the elevation information of the location information corresponds to an elevation index of a reference point of the plurality of first reference points, use, as the value of the trigonometric function corresponding to the elevation information of the location information, a trigonometric function value found in the table of trigonometric functions of elevation and corresponding to the elevation index of the reference point;or when the elevation information of the reference point corresponding to the elevation information of the location information corresponds to an elevation index of a reference point of N distinct reference points from the plurality of the first reference points, convert the elevation index of the reference point of the N points of; Rccn Ln / eznz / e / YiAi reference different from the plurality of the first reference points in an elevation index of a reference point of the plurality of the first reference points, and use, as the trigonometric function value corresponding to the elevation information of the location information, a trigonometric function value found in the table of trigonometric functions of elevation and corresponding to the elevation index of the reference point. In a possible implementation, the calculation module is specifically configured to: when the azimuth information of the location information corresponds to an azimuth index of a reference point from the plurality of second reference points, use, as the value of the trigonometric function corresponding to the azimuth information of the location information, a trigonometric function value found in the table of azimuth trigonometric functions and corresponding to the azimuth index of the reference point;or when the azimuth information of the location information corresponds to an azimuth index of a reference point of M distinct reference points of the plurality of second reference points, convert the azimuth index of the reference point of the M distinct reference points of the plurality of second reference points into an azimuth index of a reference point of the plurality of second reference points, and use, as the trigonometric function value corresponding to the azimuth information of the location information, a trigonometric function value found in the table of trigonometric functions of azimuth and corresponding to the azimuth index of the reference point;or when the azimuth information of the location information does not correspond to an azimuth index of any reference point, obtain, based on the azimuth information of the location information, azimuth information of a reference point corresponding to the azimuth information of the location information; and when the azimuth information of the reference point corresponding to the azimuth information of the location information corresponds to an azimuth index of a reference point of the plurality of second reference points, use, as the value of the trigonometric function corresponding to the azimuth information of the location information, a value of trigonometric function found in the table of trigonometric functions of azimuth and corresponding to the azimuth index of the reference point;or when the azimuth information of the reference point corresponding to the azimuth information of the location information corresponds to an azimuth index of a reference point of M distinct reference points of the plurality of second reference points, convert the azimuth index of the reference point of the M distinct reference points of the plurality of second reference points into an azimuth index of a reference point of the plurality of second reference points, and use, as the trigonometric function value corresponding to the information; Rccn Ln / eznz / e / YiAi of location information azimuth, a trigonometric function value found in the azimuth trigonometric function table and corresponding to the azimuth index of the reference point. In a possible implementation, the elevation information of the location information includes a location information elevation or a location information elevation index, and the azimuth information of the location information includes a location information azimuth or a location information azimuth index. In one possible implementation, the value of the trigonometric function is a value of the sinusoidal function or a value of the cosine function. In a possible implementation, when the plurality of trigonometric functions corresponding to the elevation indices of the plurality of first reference points are sinusoidal function values, a sinusoidal function value corresponding to an elevation index of a iavoprimer reference point satisfies the following formula (1): sin _table_N(i) = sin (^7 x Cj (1), where i=0,1, ..., and N', N'=[N / 4J, yr¡ indicates a radius of the first circle of length; or when the plurality of trigonometric functions corresponding to the elevation indices of the plurality of first reference points are cosine function values, a cosine function value corresponding to an elevation index of a iavoprimer reference point satisfies the following formula (2): eos _table_N(i) = eos (^7 xi) (2), where i=0,1, ..., and N', N'=[N / 4], and r¡ indicates a radius of the first circle of length. In a possible implementation, when the plurality of trigonometric functions corresponding to the azimuth indices of the plurality of second reference points are sinusoidal function values, a sinusoidal function value corresponding to an azimuth index of a second reference point satisfies the following formula (3): sin _table_M(j) = sin x (3), where j=0,1, ..., and M', M'=[M / 4], and η indicates a radius of the first circle of latitude; or when the plurality of trigonometric functions corresponding to the azimuth indices of the plurality of second reference points are cosine function values, a cosine function value corresponding to an azimuth index of a second reference point satisfies the following formula (4): Rccn Ln / eznz / e / YiAi eos _table_M(j) = eos xf) (4), where j=0,1, and M', M'=[M / 4], and η indicates a radius of the first circle of latitude. In a possible implementation, the elevation φ and the elevation index φ' comply with the following formula (5): ω' = round (—-—) (5), where \27rr¡x / V / v' r¡ indicates a radius of the first circle of length, and round() indicates the rounding. In a possible implementation, the azimuth Θ and the azimuth index θ' comply with the following formula (6): (Q \ ------- (6), where 2nrjXM / v' η indicates a radius of the first circle of latitude, and round() indicates rounding. In a possible implementation, when M^N, the value of the trigonometric function corresponding to the elevation information of the location information satisfies the Rccn Ln / eznz / e / YiAi following formulas: 5ίη(φ)=3ίη_ί3όΙβ_Ν(φ') φ'<|Ν / 4] sin((p)=sin_table_N(N / 2—φ') [Ν / 4]<φ'<ίΝ / 2] sin((p)=—sin_table_N(q>'—N / 2) [Ν / 2]<φ'<ί3Ν / 4] 5ίη(φ)=-5ίη_ί3όΙβ_Ν(Ν-φ') [3Ν / 4]<φ'<Ν 005(φ)=είη_ί30Ιβ_Ν(Ν / 4-φ') (p'<|N / 4J cos( <p)=-sin_table_N(q)'-N / 4) LN / 4J<cp'<LN / 2J cos(<p)=-sin_table_N(3N / 4-(p') [Ν / 2]<φ'<ί3Ν / 4] cos(<p)=sin_table_N((p'-3N / 4) |3Ν / 4]<φ'<Ν, donde φ indica la información de elevación de la información de ubicación, o φ indica la elevation information of the reference point corresponding to the elevation information of the location information, and sin_table_N() indicates the table of trigonometric elevation functions; and when M^N, the value of the trigonometric function corresponding to the azimuth information of the location information satisfies the following formulas: sin(0)=sin_table_M(0') 0'<|M / 4] sin(0)=sin_table_M(M / 2-0') LM / 4J<0' <LM / 2] sin(0)=-s¡n_table_M(0'-M / 2) LM / 2J<0'<|3M / 4J s¡n(0)=-s¡n_table_M(M-0') |3M / 4]<0'<M cos(0)=sin_table_M(M / 4-0') 0'<[M / 4] cos(0)=-sin_table_M(0'-M / 4) LM / 4J<0'<LM / 2] cos(0)=-sin_table_M(3M / 4-0') cos(0)=sin_table_M(0'-3M / 4) LM / 2J<0'<|3M / 4J |3M / 4J<0' <M, donde Rccn Ln / eznz / e / YiAi indicates the azimuth information of the location information, or 0 indicates the azimuth information of the reference point corresponding to the azimuth information of the location information, and sin_table_M() indicates the azimuth trigonometric function table. Alternatively, when M=N, the value of the trigonometric function corresponding to the elevation information of the location information satisfies the following formulas: sin(íp)=sin_table(q>') sin((p)=sin_table(N / 2-q>') sin( <p)=—sin_table(cp'—N / 2) sin((p)=—sin_table(N—φ') cos(<p)=s¡n_table(N / 4-(p') cos(cp)=-s¡n_table(q> '-N / 4) cos(9)=-sin_table(3N / 4^') cos( <p)=sin_table((p'-3N / 4) (p'<[N / 4J [Ν / 4]<φ'<[Ν / 2] [Ν / 2]<φ'<|3Ν / 4] |3Ν / 4]<φ'<Ν tp'<[N / 4J [Ν / 4]<φ'<[Ν / 2] [Ν / 2]<φ'<|3Ν / 4] |3Ν / 4]<φ'<Ν, donde φ indica la información de elevación de la información de ubicación, o φ indica la información de elevación del punto de referencia correspondiente a la información de elevación de la información de ubicación, y sin_table_N() indica la tabla de funciones trigonométricas de elevación; y cuando M=N, el valor de la función trigonométrica correspondiente a la información de azimut de la información de ubicación cumple con las siguientes fórmulas: sin(0)=sin_table(9') sin(0)=sin_table(N / 2-0') sin(0)=-sin_table(0'-N / 2) sin(0)=-sin_table(N-0') cos(0)=sin_table(N / 4-0') cos(0)=-sin_table(0'-N / 4) cos(0)=-sin_table(3N / 4-0') cos(0)=sin_table(0'-3N / 4) 0'<|N / 4J [N / 4]<0'<[N / 2] [N / 2]<0'<[3N / 4] |3N / 4]<0' <N 0'<|N / 4J LN / 4J<0' <LN / 2J [N / 2]<0'<[3N / 4] |3N / 4J<0'<N, donde indica la información de azimut de la información de ubicación, o 0 indica la información de azimut del punto de referencia correspondiente a la información de azimut de la información de ubicación, y sin_table_N() indica la tabla de funciones trigonométricas de elevación; Alternatively, when l\#N, M=K1*N and K1>2, the value of the trigonometric function corresponding to the azimuth information of the location information satisfies the following formulas: sin(0)=sin_table_M(0') sin(0)=sin_t3ble_M(M / 2-6') sin(0)=—sin_table_M(0'—M / 2) sin(0)=-sin_table_M(M-0') cos(0)=sin_table_M(M / 4-0') cos(0)=-sin_table_M(0'-M / 4) cos(0)=-sin_table_M(3M / 4-0') cos(0)=sin_table_M(0'-3M / 4) 0'<[M / 4] LM / 4J<0' <LM / 2] [M / 2J<0'<L3M / 4J [3M / 4]<0'<M 0'<|M / 4] LM / 4J<0'<LM / 2] LM / 2J<0'<|3M / 4J |3M / 4J<0'<M, donde Rccn Ln / eznz / e / YiAi θ indicates the azimuth information of the location information, or θ indicates the azimuth information of the reference point corresponding to the azimuth information of the location information, and sin_table_M() indicates the table of trigonometric azimuth functions; and when M^N, M=K1χN and K1 >2, the value of the trigonometric function corresponding to the elevation information of the location information satisfies the following formulas: sin((p)=sin_table_M(K1 χφ') sin((p)=sin_table_M(M / 2-K1 χφ') sin((p)=-sin_table_M (Κ1 χφ'-Μ / 2) sin((p)=-s¡n_table_M(M-K1 χφ') cos( <p)=sin_table_M(M / 4-K1 χφ') cos(cp)=-sin_table_M(K1 χφ'-Μ / 4) cos(<p)=-sin_table_M(3M / 4-K1 χφ') cos(<p)=sin_table_M(K1 χφ'-3Μ / 4) φ indica la información de elevación de Κ1χφ'<[Μ / 4] [M / 4]<K1 χφ'<[Μ / 2] [M / 2]<K1 χφ'<[3Μ / 4] [3Μ / 4]<Κ1χφ'<Μ Κ1χφ'<[Μ / 4] [M / 4]<K1 χφ'<[Μ / 2] [M / 2]<K1 χφ'<[3Μ / 4] |3Μ / 4]<Κ1χφ'<Μ, donde la información de ubicación, o φ indica la elevation information of the reference point corresponding to the elevation information of the location information, and sin_table_M() indicates the azimuth trigonometric function table. Alternatively, when l\#N, N=K2χM and K2>2, the value of the trigonometric function corresponding to the elevation information of the location information satisfies the following formulas: sin((p)=sin_table_N(cp') sin((p)=s¡n_table_N(N / 2-q)') sin((p)=—sin_table_N(tp'—N / 2) sin(tp)=—sin_table_N(N—φ') cos( <p)=sin_table_N(N / 4-(p') cos(<p)=-sin_table_N(q> '-N / 4) cos( <p)=-sin table Ν(3Ν / 4-φ') φ'<|Ν / 4] [Ν / 4]<φ'<ίΝ / 2] LN / 2] <q>'<|3N / 4] L3N / 4J <cp'<N (p'<|N / 4J [Ν / 4]<φ'<ίΝ / 2] |Ν / 2]<φ'<|3Ν / 4| cos( <p)=sin_table_N(cp'—3Ν / 4) [3N / 4J <cp'<N, donde Rccn Ln / eznz / e / YiAi φ indicates the elevation information of the location information, or φ indicates the elevation information of the reference point corresponding to the elevation information of the location information, and sin_table_N() indicates the table of trigonometric elevation functions; and when M^N, N=K1χN and K2>2, the value of the trigonometric function corresponding to the azimuth information of the location information satisfies the following formulas: sin(0)=sin_table_N(K2x0') sin(0)=sin_table_N(N / 2-K2x0') sin(0)=-sin_table_N(K2x0'-N / 2) sin(0)=-sin_table_N(N-K2x0') cos(0)=sin_table_N(N / 4-K2x0') cos(0)=-sin_table_N(K2x0'-N / 4) cos(0)=-sin_table_N(3N / 4-K2x0') cos(0)=sin_table_N(K2x0'-3N / 4) K2x0'<[N / 4] [N / 4] <k2x0'<ln 2] [n 2]<k2x0'<[3n 4] l3n 4]<k2x0'<n k2x0'<[n ln 4j<k2x0'<ln 2j 2j<k2x0'<|3n 4j [3n 4]<k2x0'<n, donde indica la información de azimut ubicación, o 0 del punto referencia correspondiente a y sin_table_n() tabla funciones trigonométricas elevación.Alternatively, when M^N, the value of the trigonometric function corresponding to the elevation information of the location information satisfies the following formulas: sin(0)=cos_table_N(N / 4-0') sin(0)=cos_table_N(0'-N / 4) sin(0)=-cos_table_N(3N / 4-0') sin(0)=-cos_table_N(0'-3N / 4) cos(0)=cos_table_N(0') cos(0)=-cos_table_N(N / 2-0') cos(0)=-cos_table_N(0'-N / 2) cos(0)=cos_table_N(N-0') 0'<[N / 4] LN / 4J<0' <ln 2j ln 2j<0'<|3n 4j |3n 4]<0'<n0’<|N / 4J LN / 4J<0' <ln 2j ln 2j<0'<|3n 4j |3n 4j<0'<n, donde φ indica la información de elevación ubicación, o del punto referencia correspondiente a y cos_table_n() tabla funciones trigonométricas elevación; cuando m^n, el valor función trigonométrica azimut ubicación cumple con las siguientes fórmulas:sin(0)=cos_table_M(M / 4-0') 0'<|M / 4J sin(0)=cos_table_M(0'-M / 4) LM / 4J<0' <lm 2] sin(0)="-cos_table_M(0'-3M / 4)" lm 2j<0'<|3m 4j [3m 4]<0'<m cos(0)="cos_table_M(M-0')" 0'<|m 4j<0'<lm 2j<0'<l3m |3m 4j<0'<m, dondeRccn Ln / cznz / e / YiAi Θ indicates the azimuth information of the location information, or θ indicates the azimuth information of the reference point corresponding to the azimuth information of the location information, and cos_table_M() indicates the table of trigonometric azimuth functions. In this mode, the device can be configured to perform the technical solution using the method shown in Figure 4. The application principles and technical effects are similar. Details are not described again here. In an implementation process, the steps in the previous modalities of the method can be implemented through a hardware integrated logic circuit in a processor or through instructions in a software form. The processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIO), a field-programmable gate array (FPGA), or another programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component. The general-purpose processor can be a microprocessor, or the processor can be any conventional or similar processor.The steps of the method disclosed in this application can be performed directly by a hardware encoding processor, or they can be performed using a combination of hardware and a software module within the encoding processor. The software module can be located on a mature storage medium, such as random-access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or a register. The storage medium is located in memory, and a processor reads the information from memory and completes the steps in the above methods, depending on the processor hardware. The memory mentioned in the previous modalities can be volatile or non-volatile, or it can include both. Non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory can be random access memory (RAM) and serves as an external cache.By way of example, but not as a limiting description, many forms of RAM can be used, for example, static RAM (SRAM), dynamic RAM (DRAM), synchronous dynamic RAM (SDRAM), double data rate synchronous dynamic RAM (DDR SDRAM), enhanced synchronous dynamic RAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory system and method described in this specification include, but are not limited to, these memories and any other suitable memory types. A person of ordinary skill in the art may be aware that, in combination with the examples described in the modalities disclosed in this specification, the algorithm's units and steps can be implemented using electronic hardware or a combination of computer software and electronic hardware. Whether the functions are performed by hardware or software depends on the particular applications and the design constraints of the technical solutions. A person skilled in the art may use different methods to implement the described functions for each particular application, but such implementation should not be considered to be beyond the scope of this application. It may be clearly understood by a person experienced in the technique that, for the purpose of a convenient and brief description, for a detailed work process of the above system, apparatus and unit, reference may be made to a corresponding process in the modalities of the above method, and no details are described again herein. In the various embodiments provided in this application, it should be understood that the disclosed system, apparatus, and method may be implemented in other ways. For example, the embodiment of the apparatus described is merely an example. For example, the division into units is simply a division of logical functions and may be a different division during actual implementation. For example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted or not implemented. Furthermore, the couplings shown or discussed may be mutual, direct couplings, or communication connections via various interfaces. Indirect couplings or communication connections between the apparatus or units may be implemented electrically, mechanically, or otherwise. The units described as separate parts may or may not be physically separate, and the parts shown as units may or may not be physical units; that is, Rccn Ln / eznz / e / YiAi can be located in one place, or they can be distributed across a plurality of network units. Some or all of the units can be selected according to actual requirements to achieve the solution objectives of the modalities. Additionally, the functional units in the modalities of this application may be integrated into a processing unit; each of the units may physically exist alone, or two or more units may be integrated into one unit. When functions are implemented as a functional software unit and sold or used as a standalone product, the functions may be stored on a computer-readable storage medium. Based on this understanding, technical solutions of this application, or a contributing part thereof, or some of the technical solutions, may be implemented as a software product. The computer software product is stored on a storage medium and includes various instructions for instructing a computing device (a personal computer, a server, a network device, or the like) to perform all or some of the steps of the method as described in this application.The storage medium includes: any medium that can store programming code, for example, a USB flash drive, a removable hard drive, read-only memory (ROM), random access memory (RAM), a magnetic disk, or an optical disk. The foregoing descriptions are merely specific implementations of this application, but are not intended to limit its scope of protection. Any variation or replacement readily visualized by a person skilled in the art within the technical scope described herein shall fall within the scope of protection of this application. Therefore, the scope of protection of this application shall be subject to the scope of protection of the claims.< / lm> < / ln> < / ln> < / q> < / n>

Claims

1. A method for obtaining a higher-order ambisonic HOA coefficient, characterized in that it comprises: obtaining location information of a virtual loudspeaker on a pre-established spherical surface, wherein the location information comprises elevation information and / or azimuth information, the pre-established spherical surface comprises M circles of longitude and N circles of latitude, and an intersection between the circle of longitude and the circle of latitude is called a reference point; obtaining, based on the location information and a pre-established table of reference trigonometric functions, a trigonometric function value corresponding to the location information, wherein the table of reference trigonometric functions comprises a table of elevation trigonometric functions and / or a table of azimuth trigonometric functions,The table of trigonometric functions of elevation comprises a plurality of trigonometric function values ​​corresponding to the elevation indices of a plurality of first reference points, the plurality of first reference points being reference points on a first circle of longitude, a quantity of the plurality of first reference points not less than [N / 4J+1, [J indicates rounding down, the first circle of longitude is one of the M circles of longitude, the table of trigonometric functions of azimuth comprises a plurality of trigonometric function values ​​corresponding to the azimuth indices of a plurality of second reference points, the plurality of second reference points being reference points on a first circle of latitude, a quantity of the plurality of second reference points not less than [M / 4J+1,and the first latitude circle is one of the N latitude circles; and obtain an HOA coefficient for the virtual speaker based on the value of the trigonometric function corresponding to the location information.

2. The method according to claim 1, characterized in that obtaining, based on location information and a pre-established reference trigonometric function table, a trigonometric function value corresponding to the location information comprises: obtaining, based on the elevation information of the location information and the elevation trigonometric function table, a trigonometric function value corresponding to the elevation information of the location information; and / or obtaining, based on the azimuth information of the location information and the azimuth trigonometric function table, a trigonometric function value corresponding to the azimuth information of the location information. Rccn Ln / eznz / e / YiAi 3. The method according to claim 2, characterized in that obtaining, based on the elevation information of the location information and the table of trigonometric elevation functions, a trigonometric function value corresponding to the elevation information of the location information comprises: when the elevation information of the location information corresponds to an elevation index of a reference point of the plurality of first reference points, using, as the trigonometric function value corresponding to the elevation information of the location information, a trigonometric function value found in the table of trigonometric elevation functions and corresponding to the elevation index of the reference point;or when the elevation information of the location information corresponds to an elevation index of a reference point of N distinct reference points from the plurality of the first reference points, convert the elevation index of the reference point of the N distinct reference points from the plurality of the first reference points into an elevation index of a reference point from the plurality of the first reference points, and use, as the trigonometric function value corresponding to the elevation information of the location information, a trigonometric function value found in the table of trigonometric functions of elevation and corresponding to the elevation index of the reference point;or when the elevation information of the location information does not correspond to an elevation index of any reference point, obtain, based on the elevation information of the location information, elevation information of a reference point corresponding to the elevation information of the location information; and when the elevation information of the reference point corresponding to the elevation information of the location information corresponds to an elevation index of a reference point of the plurality of first reference points, use, as the value of the trigonometric function corresponding to the elevation information of the location information, a trigonometric function value found in the table of trigonometric functions of elevation and corresponding to the elevation index of the reference point;or when the elevation information of the reference point corresponding to the elevation information of the location information corresponds to an elevation index of a reference point of N distinct reference points of the plurality of the first reference points, convert the elevation index of the reference point of the N distinct reference points of the plurality of the first reference points into an elevation index of a reference point of the plurality of the first reference points, and use, as the trigonometric function value corresponding to the elevation information of the location information, a trigonometric function value found in the table of trigonometric functions of elevation and corresponding to the elevation index of the reference point.

4. The method according to claim 2, characterized in that obtaining, based on the azimuth information of the location information and the table of azimuth trigonometric functions, a trigonometric function value corresponding to the azimuth information of the location information comprises: when the azimuth information of the location information corresponds to an azimuth index of a reference point of the plurality of second reference points, using, as the trigonometric function value corresponding to the azimuth information of the location information, a trigonometric function value found in the table of azimuth trigonometric functions and corresponding to the azimuth index of the reference point;or when the azimuth information of the location information corresponds to an azimuth index of a reference point of M distinct reference points of the plurality of second reference points, convert the azimuth index of the reference point of the M distinct reference points of the plurality of second reference points into an azimuth index of a reference point of the plurality of second reference points, and use, as the trigonometric function value corresponding to the azimuth information of the location information, a trigonometric function value found in the table of azimuth trigonometric functions and corresponding to the azimuth index of the reference point;or when the azimuth information of the location information does not correspond to an azimuth index of any reference point, obtain, based on the azimuth information of the location information, azimuth information of a reference point corresponding to the azimuth information of the location information; and when the azimuth information of the reference point corresponding to the azimuth information of the location information corresponds to an azimuth index of a reference point of the plurality of second reference points, use, as the value of the trigonometric function corresponding to the azimuth information of the location information, a value of trigonometric function found in the table of trigonometric functions of azimuth and corresponding to the azimuth index of the reference point;or when the azimuth information of the reference point corresponding to the azimuth information of the location information corresponds to an azimuth index of a reference point of M distinct reference points of the plurality of second reference points, convert the azimuth index of the reference point of the M distinct reference points of the plurality of second reference points into an azimuth index of a reference point of the plurality of second reference points Rccn Ln / eznz / e / YiAi, and use, as the trigonometric function value corresponding to the azimuth information of the location information, a trigonometric function value found in the table of trigonometric azimuth functions and corresponding to the azimuth index of the reference point.

5. The method according to any of claims 2 to 4, characterized in that the elevation information of the location information comprises a location information elevation or a location information elevation index, and the azimuth information of the location information comprises a location information azimuth or a location information azimuth index.

6. The method according to any of claims 1 to 5, characterized in that the trigonometric function value is a sinusoidal function value or a cosine function value.

7. The method according to any of claims 1 to 6, characterized in that when the plurality of trigonometric functions corresponding to the elevation indices of the plurality of first reference points are sinusoidal function values, a sinusoidal function value corresponding to an elevation index of a first reference point satisfies the following formula (1): sin_table_N(i) = sin(7 x Cj (1), wherein i = 0, 1, ..., and N', N' = [N / 4J, and r' indicates a radius of the first circle of length; or when the plurality of trigonometric functions corresponding to the elevation indices of the plurality of first reference points are cosine function values, a cosine function value corresponding to an elevation index of a first reference point satisfies the following formula (2): cos_table_N(i) = cos x (2), wherein i = 0, 1, ..., and N', N'=[N / 4], yr¡ indicates a radius of the first circle of length.

8. The method according to any of claims 1 to 7, characterized in that when the plurality of trigonometric functions corresponding to the azimuth indices of the plurality of second reference points are sinusoidal function values, a sinusoidal function value corresponding to an azimuth index of a second reference point satisfies the following formula (3): sin_table_M(j) = sin_xf) (3), wherein j=0,1, ..., and M', M'=[M / 4], and η indicates a radius of the first circle of latitude; or Rccn Ln / eznz / e / YiAi when the plurality of trigonometric functions corresponding to the azimuth indices of the plurality of second reference points are cosine function values, a cosine function value corresponding to an azimuth index of a second reference point satisfies the following formula (4): eos _table_M(j) = eos x jj (4), where Rccn Ln / eznz / e / YiAi j=0,1, ..., and M', M'=[M / 4], and η indicates a radius of the first circle of latitude.

9. The method according to any of claims 2 to 5, characterized in that the elevation φ and the elevation index φ' comply with the following formula (5): φ' = round (—-—) (5), wherein \2πΓ(XN / ' ' r¡ indicates a radius of the first circle of length, and round() indicates the rounding.

10. The method according to any of claims 2 to 5, characterized in that the azimuth θ and the azimuth index θ' comply with the following formula (6): (Θ \ ------ (6), wherein 2πΓ;·χM / η indicates a radius of the first circle of latitude, and round() indicates rounding.

11. The method according to claim 9 or 10, characterized in that when M^N, the value of the trigonometric function corresponding to the elevation information of the location information complies with the following formulas: sin(ip)=sin_table_N(cp') sin((p)=sin_table_N(N / 2-q)') sin(ip)=—sin_table_N(tp'—N / 2) sin((p)=-sin_table_N(Nq)') cos( <p)=sin_table_N(N / 4-q)') cos(<p)=-sin_table_N(q> '-N / 4) cos(cp)=-sin_table_N(3N / 4- <p') cos(<p)=sin_table_N(q)'-3N / 4) φ<[Ν / 4] [Ν / 4]<φ'<[Ν / 2] [Ν / 2]<φ'<[3Ν / 4] |3Ν / 4]<φ'<Ν φ'<[Ν / 4] [Ν / 4]<φ'<[Ν / 2] [Ν / 2]<φ'< [3N / 4J [3Ν / 4]<φ'<Ν, en donde φ indica la información de elevación de la información de ubicación, o φ indica la información de elevación del punto de referencia correspondiente a la información de elevación de la información de ubicación, y sin_table_N() indica la tabla de funciones trigonométricas de elevación;and when M^N, the value of the trigonometric function corresponding to the azimuth information of the location information satisfies the following formulas: sin(0)=sin_table_M(e') sin(0)=sin_table_M(M / 2-e') θ'<[M / 4] [M / 4]<θ'<[M / 2] sin(0)=-sin_table_M(0'-M / 2) sin(0)=-sin_table_M(M-0') cos(0)=sin_table_M(M / 4-0') cos(0)=-sin_table_M(0'-M / 4) cos(0)=-sin_table_M(3M / 4-0') cos(0)=sin_table_M(0'-3M / 4) LM / 2J<0'<|3M / 4J |3M / 4]<0' <M 0'<[M / 4] [M / 4]<0'<[M / 2] [M / 2]<0'<[3M / 4J |3M / 4J<0'<M, en donde Rccn Ln / eznz / e / YiAi Θ indica la información de azimut de la información de ubicación, o Θ indica la información de azimut del punto de referencia correspondiente a la información de azimut de la información de ubicación, y sin_table_M() indica la tabla de funciones trigonométricas de azimut;or When M=N, the value of the trigonometric function corresponding to the elevation information of the location information complies with the following formulas: sin(íp)=sin_table(q>') sin(íp)=sin_table(N / 2—φ') sin(tp)=—sin_table(q)'—N / 2) sin( <p)=—sin_table(N—φ') cos(<p)=sin_table(N / 4-(p') cos(<p)=-sin_table((p'-N / 4) cos(cp)=-s¡n_table(3N / 4-(p') cos(<p)=sin_table((p'-3N / 4) φ indica la información de elevación de φ'<[Ν / 4] [Ν / 4]<φ'<[Ν / 2] LN / 2J; <q>'<|3N / 4] |3Ν / 4]<φ'<Ν φ'<[Ν / 4] [Ν / 4]<φ'<[Ν / 2] [N / 2J <tp'<[3N / 4] [3Ν / 4]<φ'<Ν, en donde la información de ubicación, o φ indica la información de elevación del punto de referencia correspondiente a la información de elevación de la información de ubicación, y sin_table_N() indica la tabla de funciones trigonométricas de elevación;and when M=N, the value of the trigonometric function corresponding to the azimuth information of the location information fulfills the following formulas: sin(0)=sin_table(0') sin(0)=sin_table(N / 2-0') sin(0)=-sin_table(0'-N / 2) sin(0)=-sin_table(N-0') cos(0)=sin_table(N / 4-0') cos(0)=-sin_table(0'-N / 4) cos(0)=-sin_table(3N / 4-0') cos(0)=sin_table(0'-3N / 4) 0' <LN / 4J [N / 4]<0'<[N / 2] [N / 2]<0'<[3N / 4] |3N / 4]<0'<N 0’<|N / 4J LN / 4J<0'<LN / 2J LN / 2J<0'<|3N / 4J |3N / 4]<0'<N, en donde θ indica la información de azimut de la información de ubicación, o θ indica la información de azimut del punto de referencia correspondiente a la información de azimut de la información de ubicación, y sin_table_N() indica la tabla de funciones trigonométricas de elevación;or when M^N, M=K1χN and K1>2, the value of the trigonometric function corresponding to the azimuth information of the location information satisfies the following formulas: Rccn Ln / eznz / B / γΐΛΐ s¡n(8)=s¡n_table_M(e') 0'<|M / 4J sin(8)=s¡n_table_M(M / 2-6') LM / 4J <e'<LM / 2J sin(0)=—sin_table_M(0'—M / 2) LM / 2J<e'<|3M / 4J sin(0)=-sin_table_M(M-e') [3Μ / 4]<θ'<Μ cos(9)=sin_table_M(M / 4-0') 0'<|M / 4J cos(0)=-s¡n_table_M(6'-M / 4) [Μ / 4]<θ'<[Μ / 2] cos(0)=-sin_table_M(3M / 4-0') [Μ / 2]<θ'<[3Μ / 4] cos(0)=sin_table_M(6'-3M / 4) [3M / 4J<0'<M, en donde Θ indica la información de azimut de la información de ubicación, o θ indica la información de azimut del punto de referencia correspondiente a la información de azimut de la información de ubicación, y sin_table_M() indica la tabla de funciones trigonométricas de azimut;and when M^N, M=K1χN and K1 >2, the value of the trigonometric function corresponding to the elevation information of the Location Information satisfies the following formulas: sin((p)=sin_table_M(K1 χφ') K1 χφ'<[M / 4] sin((p)=sin_table_M(M / 2-K1 χφ') [M / 4]<K1 xq> ' <LM / 2] sin((p)=-sin_table_M(K1 χφ'-Μ / 2) [M / 2]<K1 χφ'<[3Μ / 4] sin(íp)=—sin_table_M (Μ—Κ1 χφ') [3Μ / 4]<Κ1χφ'<Μ cos((p)=s¡n_table_M(M / 4-K1 χφ') Κ1χφ'<[Μ / 4] cos(<p)=-sin_table_M(K1 χφ'-Μ / 4) [M / 4]<K1 χφ'<[Μ / 2] cos((p)=-sin_table_M(3M / 4-K1 χφ') [M / 2]<K1 χφ'<[3Μ / 4] cos(<p)=sin_table_M(K1 χφ'-3Μ / 4) [3M / 4J<K1 χφ'<Μ, en donde φ indica la información de elevación de la información de ubicación, o φ indica la información de elevación del punto de referencia correspondiente a la información de elevación de la información de ubicación, y sin_table_M() indica la tabla de funciones trigonométricas de azimut;or when M^N, N=K1χN and K2>2, the value of the trigonometric function corresponding to the elevation information of the location information satisfies the following formulas: sin((p)=sin_table_N(q>') sin((p)=sin_table_N(N / 2—φ') φ'<[N / 4] [N / 4]<φ'<[N / 2] sin(tp)=—sin_table_N(tp'—N / 2) sin(tp)=—sin_table_N(N—φ') cos( <p)=sin_table_N(N / 4-tp') cos(<p)=-sin_table_N(q> '-N / 4) cos( <p)=-sin_table_N(3N / 4-<p') cos(<p)=s¡n_table_N((p'-3N / 4) φ indica la información de elevación de [N / 2J<tp'<[3N / 4] L3N / 4]<cp'<N φ'<[Ν / 4] [Ν / 4]<φ'<[Ν / 2] [Ν / 2]<φ'<|3Ν / 4] |3Ν / 4]<φ'<Ν, en donde la información de ubicación, o φ indica la información de elevación del punto de referencia correspondiente a la información de elevación de la información de ubicación, y sin_table_N() indica la tabla de funciones trigonométricas de elevación;and when M^N, N=K1*N and K2>2, the value of the trigonometric function corresponding to the azimuth information of the location information satisfies the following formulas: sin(0)=sin_table_N(K2x0') sin(0)=sin_table_N(N / 2-K2x0') sin(0)=-sin_table_N(K2x0'-N / 2) sin(0)=-sin_table_N(N-K2x0') cos(0)=sin_table_N(N / 4-K2x0') cos(0)=-sin_table_N(K2x0'-N / 4) cos(0)=-sin_table_N(3N / 4-K2x0') cos(0)=sin_table_N(K2x0'-3N / 4) K2x0'<[N / 4] LN / 4J <K2x0'<LN / 2J LN / 2J<K2x0'<L3N / 4J [3N / 4]<K2x0'<N K2x0'<[N / 4] LN / 4J<K2x0'<LN / 2J LN / 2J<K2x0'<L3N / 4J |3Ν / 4]<Κ2χ0'<Ν, en donde θ indica la información de azimut de la información de ubicación, o θ indica la información de azimut del punto de referencia correspondiente a la información de azimut de la información de ubicación, y sin_table_N() indica la tabla de funciones trigonométricas de elevación;or when M^N, the value of the trigonometric function corresponding to the elevation information of the location information meets the following formulas: sin(0)=cos_table_N(N / 4-0') sin(0)=cos_table_N(0'-N / 4) sin(0)=-cos_table_N(3N / 4-0') sin(0)=-cos_table_N(0'-3N / 4) cos(0)=cos_table_N(0') cos(0)=-cos_table_N(N / 2-0') cos(0)=-cos_table_N(0'-N / 2) cos(0)=cos_table_N(N-0') φ indicates the elevation information of 0' <LN / 4J [N / 4]<0'<[N / 2] [N / 2]<0'<[3N / 4] |3N / 4]<0'<N 0’<|N / 4J LN / 4J<0'<LN / 2J LN / 2J<0'<|3N / 4J |3N / 4]<0'<N, en donde la información de ubicación, o φ indica la información de elevación del punto de referencia correspondiente a la información de elevación de la información de ubicación, y cos_table_NQ indica la tabla de funciones trigonométricas de elevación;and when M^N, the value of the trigonometric function corresponding to the azimuth information of the location information complies with the following formulas: Rccn Ln / eznz / e / YiAi s¡n(0)=cos_table_M(M / 4-8') sin(8)=cos_table_M(0'-M / 4) sin(0)=-cos_table_M(3M / 4-0') 5η(θ)=-005_ί30θ_M(θ'-3M / 4) cos(9)=cos_table_M(0') cos(0)=-cos_table_M(M / 2-9') cos(0)=-cos_table_M(6'-M / 2) cos(0)=cos_table_M(M-6') 0'<|M / 4J LM / 4J <e'<LM / 2J LM / 2J<e'<|3M / 4J |3Μ / 4]<θ'<Μ θ'<[Μ / 4] [Μ / 4]<θ'<[Μ / 2] [Μ / 2]<θ'<[3Μ / 4] [3M / 4J<0'<M, en donde θ indica la información de azimut de la información de ubicación, o θ indica la información de azimut del punto de referencia correspondiente a la información de azimut de la información de ubicación, y cos_table_M() indica la tabla de funciones trigonométricas de azimut.; 12. The method according to any of claims 1 to 11, characterized in that N reference points located on a longitude circle are arranged at equal intervals, and M reference points located on a latitude circle are arranged at equal intervals.

13. An apparatus for obtaining a higher-order ambisonic HOA coefficient, characterized in that it comprises: a acquisition module, configured to obtain location information of a virtual loudspeaker on a pre-established spherical surface, wherein the location information comprises elevation and / or azimuth information, the pre-established spherical surface comprises M circles of longitude and N circles of latitude, an intersection between the circle of longitude and the circle of latitude is called a reference point, N reference points located on a circle of longitude are arranged at equal intervals, and M reference points located on a circle of latitude are arranged at equal intervals; and a calculation module, configured to: obtain, based on the location information and a pre-established reference trigonometric function table, a trigonometric function value corresponding to the location information,wherein the reference trigonometric function table comprises a table of elevation trigonometric functions and / or a table of azimuth trigonometric functions, the elevation trigonometric function table comprises a plurality of trigonometric function values ​​corresponding to the elevation indices of a plurality of first reference points, the plurality of first reference points being reference points on a first longitude circle, a quantity of the plurality of first reference points not less than [N / 4J+1, [ ] indicates rounding down, the first longitude circle being one of the M longitude circles, the azimuth trigonometric function table comprises a plurality of trigonometric function values ​​corresponding to the azimuth indices of a plurality of second reference points, the plurality of second reference points being reference points on a first latitude circle,a quantity of the plurality of second reference points is not less than [M / 4J+1, and the first circle of latitude is one of the N circles of latitude; and obtain an HOA coefficient for the virtual loudspeaker based on the value of the trigonometric function corresponding to the location information.

14. The apparatus according to claim 13, characterized in that the calculation module is specifically configured to: obtain, based on the elevation information of the location information and the table of elevation trigonometric functions, a trigonometric function value corresponding to the elevation information of the location information; and / or obtain, based on the azimuth information of the location information and the table of azimuth trigonometric functions, a trigonometric function value corresponding to the azimuth information of the location information.

15. The apparatus according to claim 14, characterized in that the calculation module is specifically configured to: when the elevation information of the location information corresponds to an elevation index of a reference point from the plurality of first reference points, use, as the trigonometric function value corresponding to the elevation information of the location information, a trigonometric function value found in the table of trigonometric elevation functions and corresponding to the elevation index of the reference point;or when the elevation information of the location information corresponds to an elevation index of a reference point of N distinct reference points of the plurality of the first reference points, convert the elevation index of the reference point of the N distinct reference points of the plurality of the first reference points into an elevation index of a reference point of the plurality of first reference points, and use, as the trigonometric function value corresponding to the elevation information of the location information, a trigonometric function value found in the table of trigonometric functions of elevation and corresponding to the elevation index of the reference point;or when the elevation information of the location information does not correspond to an elevation index of any reference point, obtain, based on the elevation information of the location information, elevation information of a reference point corresponding to the elevation information of the location information; and when the elevation information of the reference point corresponding to the elevation information of the location information corresponds to an elevation index of a reference point of the plurality of first reference points, use, as the value of the trigonometric function corresponding to the elevation information of the location information, a trigonometric function value found in the table of trigonometric functions of elevation and corresponding to the elevation index of the reference point;or when the elevation information of the reference point corresponding to the elevation information of the location information corresponds to an elevation index of a reference point of N distinct reference points of the plurality of the first reference points, convert the elevation index of the reference point of the N distinct reference points of the plurality of the first reference points into an elevation index of a reference point of the plurality of the first reference points, and use, as the trigonometric function value corresponding to the elevation information of the location information, a trigonometric function value found in the table of trigonometric functions of elevation and corresponding to the elevation index of the reference point.

16. The apparatus according to claim 14, characterized in that the calculation module is specifically configured to: when the azimuth information of the location information corresponds to an azimuth index of a reference point of the plurality of second reference points, use, as the value of the trigonometric function corresponding to the azimuth information of the location information, a value of the trigonometric function found in the table of azimuth trigonometric functions and corresponding to the azimuth index of the reference point;or when the azimuth information of the location information corresponds to an azimuth index of a reference point of M distinct reference points of the plurality of second reference points, convert the azimuth index of the reference point of the M distinct reference points of the plurality of second reference points into an azimuth index of a reference point of the plurality of second reference points, and use, as the value of the trigonometric function corresponding to the azimuth information of the location information, a value of the trigonometric function found in the table of trigonometric functions of azimuth and corresponding to the azimuth index of the reference point;or when the azimuth information of the location information does not correspond to an azimuth index of any reference point, obtain, based on the azimuth information of the location information, azimuth information of a reference point corresponding to the azimuth information of the location information; and when the azimuth information of the reference point Rccn Ln / eznz / e / YiAi corresponding to the azimuth information of the location information corresponds to an azimuth index of a reference point of the plurality of second reference points, use, as the value of the trigonometric function corresponding to the azimuth information of the location information, a value of trigonometric function found in the table of trigonometric functions of azimuth and corresponding to the azimuth index of the reference point;or when the azimuth information of the reference point corresponding to the azimuth information of the location information corresponds to an azimuth index of a reference point of M distinct reference points of the plurality of second reference points, convert the azimuth index of the reference point of the M distinct reference points of the plurality of second reference points into an azimuth index of a reference point of the plurality of second reference points, and use, as the trigonometric function value corresponding to the azimuth information of the location information, a trigonometric function value found in the table of trigonometric azimuth functions and corresponding to the azimuth index of the reference point.

17. The apparatus according to any of claims 14 to 16, characterized in that the elevation information of the location information comprises a location information elevation or a location information elevation index, and the azimuth information of the location information comprises a location information azimuth or a location information azimuth index.

18. The apparatus according to any of claims 13 to 17, characterized in that the trigonometric function value is a sinusoidal function value or a cosine function value.

19. The apparatus according to any of claims 13 to 18, characterized in that when the plurality of trigonometric functions corresponding to the elevation indices of the plurality of first reference points are sinusoidal function values, a sinusoidal function value corresponding to an elevation index of a first reference point satisfies the following formula (1): sin_table_N(i) = sin_xi) (1), wherein i=0,1, ..., and N', N'=[N / 4J, yr¡ indicates a radius of the first circle of length; or when a plurality of trigonometric functions corresponding to the elevation information of the plurality of first reference points are cosine function values, a cosine function value corresponding to the elevation information of a first reference point satisfies the following formula (2): Rccn Ln / eznz / e / YiAi eos _table_N(i) = eos X i) (2), where i=0,1, and N', N'=[N / 4], yr¡ indicates a radius of the first circle of length.

20. The apparatus according to any of claims 13 to 19, characterized in that when the plurality of trigonometric functions corresponding to the azimuth indices of the plurality of second reference points are sinusoidal function values, a sinusoidal function value corresponding to an azimuth index of a second reference point complies with the following formula (3): sin_table_M(j) = sin_xf) (3), wherein j=0,1, ..., and M', M'=[M / 4], and η indicates a radius of the first circle of latitude; or when a plurality of trigonometric functions corresponding to the azimuth information of the plurality of second reference points are cosine function values, a cosine function value corresponding to the azimuth information of a second reference point satisfies the following formula (4): eos _table_M(j) = eos xf) (4), wherein j=0, 1, ..., and M', M'=|M / 4], and η denotes a radius of the first circle of latitude.

21. The apparatus according to any of claims 14 to 17, characterized in that the elevation φ and the elevation index φ' comply with the following formula (5): ω' = round (—-—) (5), wherein \277-r,xW / ' ' r¡ indicates a radius of the first circle of length, and round() indicates the rounding.

22. The apparatus according to any of claims 14 to 17, characterized in that the azimuth θ and the azimuth index θ' comply with the following formula (6): (Q \ -------) (6), wherein 2rcr;xM / ' ' η indicates a radius of the first latitude circle, and round() indicates the rounding.

23. The apparatus according to claim 21 or 22, characterized in that when M^N, the value of the trigonometric function corresponding to the elevation information of the location information complies with the following formulas: Rccn Ln / eznz / e / YiAi sin(íp)=sin_table_N(cp') sin(íp)=sin_table_N(N / 2—φ') sin(tp)=—sin_table_N(tp'—N / 2) sin((p)=-sin_table_N(Nq>') φ'<[N / 4] |N / 4]<φ'<|N / 2] |N / 2]<φ'<|3N / 4] |3N / 4]<φ'<N cos((p)=sin_table_N(N / 4-(p') cos( <p)=-sin_table_N(q)'-N / 4) cos(<p)=-sin_table_N(3N / 4-<p') cos(<p)=s¡n_table_N(q> '-3N / 4) φ indicates the elevation information of φ'<[N / 4] [N / 4]<φ'<[N / 2] [N / 2]<φ'<[3N / 4] |3N / 4]<φ'<N, where the location information, or φ indicates the elevation information of the reference point corresponding to the elevation information of the location information, and sin_table_N() indicates the table of trigonometric elevation functions;and when M^N, the value of the trigonometric function corresponding to the azimuth information of the location information satisfies the following formulas: sin(0)=sin_table_M(e') sin(0)=sin_table_M(M / 2-0') sin(0)=-sin_table_M(0'-M / 2) sin(0)=-sin_table_M(M-0') cos(0)=sin_table_M(M / 4-0') cos(0)=-sin_table_M(0'-M / 4) cos(0)=-sin_table_M(3M / 4-0') cos(0)=sin_table_M(0'-3M / 4) 0'<[M / 4] [M / 4J<0' <LM / 2] LM / 2J<0'<|3M / 4J |3M / 4J<0'<M 0’<LM / 4J |Μ / 4]<θ'<|Μ / 2] [M / 2]<0'<[3M / 4] |3M / 4J<0'<M, en donde Θ indica la información de azimut de la información de ubicación, o Θ indica la información de azimut del punto de referencia correspondiente a la información de azimut de la información de ubicación, y sin_table_M() indica la tabla de funciones trigonométricas de azimut;or When M=N, the value of the trigonometric function corresponding to the elevation information of the location information complies with the following formulas: sin((p)=sin_table(q>') sin(ip)=sin_table(N / 2—φ') sin(tp)=—sin_table(q>'—N / 2) sin(ip)=—sin_table(N—φ') cos( <p)=sin_table(N / 4-q)') cos(<p)=-sin_table((p'-N / 4) cos(<p)=-sin_table(3N / 4-(p') cos(cp)=sin_table((p'-3N / 4) φ indica la información de elevación de φ'<[Ν / 4] [Ν / 4]<φ'<[Ν / 2] [Ν / 2]<φ'<[3Ν / 4] |3Ν / 4]<φ'<Ν φ'<[Ν / 4] [Ν / 4]<φ'<[Ν / 2] [Ν / 2]<φ'<[3Ν / 4] [3N / 4J<<p'<N, en donde la información de ubicación, o φ indica la información de elevación del punto de referencia correspondiente a la información de elevación de la información de ubicación, y sin_table_N() indica la tabla de funciones trigonométricas de elevación;and when M=N, the value of the trigonometric function corresponding to the azimuth information of the location information complies with the following formulas: Rccn Ln / eznz / e / YiAi sin(0)=sin_table(0') sin(0)=sin_table(N / 2-0') sin(0)=-sin_table(0'-N / 2) sin(0)=-sin_table(N-0') cos(0)=sin_table(N / 4-0') cos(0)=-sin_table(0'-N / 4) cos(0)=-sin_table(3N / 4-0') cos(0)=sin_table(0'-3N / 4) 0'<[N / 4] [N / 4]<0'<[N / 2J [N / 2]<0'<[3N / 4] |3N / 4J<0' <N 0'<LN / 4J |N / 4J<0'<|N / 2J |N / 2J<0'<|3N / 4] |3N / 4J<0'<N, en donde θ indica la información de azimut de la información de ubicación, o θ indica la información de azimut del punto de referencia correspondiente a la información de azimut de la información de ubicación, sin_table_N() indica la tabla de funciones trigonométricas de elevación, y la tabla de funciones trigonométricas de elevación comprende una pluralidad de valores de función sinusoidal correspondientes a la información de elevación de la pluralidad de primeros puntos de referencia;or when M^N, M=K1χN and K1 >2, the value of the trigonometric function corresponding to the azimuth information of the location information satisfies the following formulas: sin(0)=sin_table_M(0') sin(0)=sin_table_M(M / 2-0') sin(0)=—sin_table_M(0'—M / 2) sin(0)=—sin_table_M(M—0') cos(0)=sin_table_M(M / 4-0') cos(0)=-sin_table_M(0'-M / 4) cos(0)=-sin_table_M(3M / 4-0') cos(0)=sin_table_M(0'-3M / 4) 0'<[M / 4J |M / 4]<θ'<|M / 2] [M / 2]<0'<[3M / 4] |3M / 4J<0' <M 0’<LM / 4J LM / 4]<0'<[M / 2] LM / 2J<0'<|3M / 4J |3M / 4J<0'<M, en donde θ indica la información de azimut de la información de ubicación, o θ indica la información de azimut del punto de referencia correspondiente a la información de azimut de la información de ubicación, sin_table_M() indica la tabla de funciones trigonométricas de azimut, y la tabla de funciones trigonométricas de azimut comprende una pluralidad de valores de función sinusoidal correspondientes a la información de azimut de la pluralidad de segundos puntos de referencia;and when M^N, M=K1χN and K1>2, the value of the trigonometric function corresponding to the elevation information of the location information satisfies the following formulas: sin((p)=sin_table_M(K1 χφ') sin((p)=sin_table_M(M / 2-K1 χφ') sin((p)=-sin_table_M(K1 χφ'-M / 2) sin((p)=-sin_table_M(M-K1 χφ') cos( <p)=sin_table_M(M / 4-K1 χφ') cos(cp)=-sin_table_M(K1 χφ'-Μ / 4) cos(<p)=-sin_table_M(3M / 4-K1 χφ') cos(<p)=sin_table_M(K1 χφ'-3Μ / 4) φ indica la información de elevación de Κ1 χφ'<[Μ / 4] LM / 4J<K1 xqj'<LM / 2J [Μ / 2]<Κ1 χφ'<|3Μ / 4] |3M / 4]<K1 χφ'<Μ Κ1 χφ'<[Μ / 4] LM / 4J<K1 xtp'<LM / 2J [M / 2]<K1 χφ'<|3Μ / 4] |3Μ / 4]<Κ1χφ'<Μ, en donde la información de ubicación, o φ indica la información de elevación del punto de referencia correspondiente a la información de elevación de la información de ubicación, y sin_table_M() indica la tabla de funciones trigonométricas de azimut;or when M^N, N=K1*N and K2>2, the value of the trigonometric function corresponding to the elevation information of the location information satisfies the following formulas: sin((p)=sin_table_N(cp') sin((p)=sin_table_N(N / 2—φ') sin(tp)=—sin_table_N(tp'—N / 2) sin(tp)=—sin_table_N(N—φ') cos( <p)=sin_table_N(N / 4-cp') cos(<p)=-sin_table_N(q> '-N / 4) cos( <p)=-sin_table_N(3N / 4-<p') cos(<p)=sin_table_N((p'-3N / 4) φ indica la información de elevación de φ'<|Ν / 4] |Ν / 4]<φ'<|Ν / 2] |Ν / 2]<φ'<|3Ν / 4] |3Ν / 4]<φ'<Ν φ'<[Ν / 4] [Ν / 4]<φ'<[Ν / 2] [Ν / 2]<φ'<[3Ν / 4] |3Ν / 4]<φ'<Ν, en donde la información de ubicación, o φ indica la información de elevación del punto de referencia correspondiente a la información de elevación de la información de ubicación, y sin_table_N() indica la tabla de funciones trigonométricas de elevación;and when M^N, N=K1*N and K2>2, the value of the trigonometric function corresponding to the azimuth information of the location information satisfies the following formulas: sin(0)=sin_table_N(K2x0') sin(0)=sin_table_N(N / 2-K2x0') sin(0)=-sin_table_N(K2x0'-N / 2) sin(0)=-sin_table_N(N-K2x0') cos(0)=sin_table_N(N / 4-K2x0') K2x0'<[N / 4] LN / 4J; <k2x0'<ln 2j ln 2j<k2x0'<l3n 4j [3n 4]<k2x0'<n k2x0'<[n 4] cos(0)="cos_table_M(M-0')" 4j<k2x0'<ln |3n 4j<k2x0'<n, en donde 0 indica la información de azimut ubicación, o del punto referencia correspondiente a y sin_table_n() tabla funciones trigonométricas elevación; cuando m^n, el valor función trigonométrica elevación ubicación cumple con las siguientes fórmulas: sin(0)="-cos_table_M(0'-3M / 4)" 0'<[n [n 4]<0'<[n 2] 2]<0'<[3n 4j<0'<n 0'<ln 4j<0'<ln |n 2j<0'<|3n 4]<0'<n, φ cos_table_no lm 4j<0'<lm 2j<0'<|3m |3m 4j<0'<m |m 4j<0'<|m [m 2]<0'<[3m 4j<0'<m, cos_table_m() azimut.

24. The apparatus according to any of claims 13 to 23, characterized in that N reference points located on a longitude circle are arranged at equal intervals, and M reference points located on a latitude circle are arranged at equal intervals.

25. An audio processing device, characterized in that it comprises: one or more processors; and a memory, configured to store one or more programs, wherein when one or more programs are executed by one or more processors, one or more processors are enabled to implement the method in accordance with any of claims 1 to 12.

26. A computer-readable storage medium, characterized in that it comprises a computer program, wherein, when the computer program is executed on a computer, the computer is enabled to perform the method in accordance with any one of claims 1 to 12. < / q>

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