阅读说明：本技术 一种新型的低音回放方法和装置 (Novel bass playback method and device ) 是由 张国良 于 2021-08-25 设计创作，主要内容包括：本发明公开了一种新型的低音回放方法,包括以下步骤：S1,将输入的音频信号采样到第一目标采样率M；S2,采用滤波器组进行计算,确定第二目标子带宽度、N个第二目标子带数量以及计算得出第二目标采样率M′；S3,根据S2所得出的第二目标采样率M′,将第一目标采样率M采样至第二目标采样率M′；S4,将第二目标采样率M′通过滤波器组进行分频；S5,按照巴克尺度将N个第二目标子带进行分组,得到若干个第二目标子带组；S6,形成对应若干个第三目标信号；S7,将若干个第三目标信号通过不同的扬声器单元进行回放。本发明提供了一种新型的低音回放方法,解决低音音响回放保真度不够好的问题。本发明还提供了一种新型的低音回放装置。(The invention discloses a novel bass playback method, which comprises the following steps: s1, sampling the input audio signal to a first target sampling rate M; s2, calculating by using a filter bank, determining a second target subband width, N second target subband quantities and calculating to obtain a second target sampling rate M'; s3, sampling the first target sampling rate M to a second target sampling rate M 'according to the second target sampling rate M' obtained in the S2; s4, dividing the frequency of the second target sampling rate M' through a filter bank; s5, grouping the N second target sub-bands according to the bark scale to obtain a plurality of second target sub-band groups; s6, forming a plurality of corresponding third target signals; s7, playing back a plurality of third target signals through different speaker units. The invention provides a novel bass playback method, which solves the problem that the playback fidelity of bass sound is not good enough. The invention also provides a novel bass playback device.)

1. A novel bass playback method, comprising the steps of:

s1, sampling the input audio signal to a first target sampling rate M, wherein the first target sampling rate is twice of the highest low sound frequency point of the input audio;

s2, calculating by adopting a filter bank, determining a second target subband width, N second target subband quantities and calculating to obtain a second target sampling rate M' according to the first target sampling rate M sampled in S1;

s3, sampling the first target sampling rate M to a second target sampling rate M 'according to the second target sampling rate M' obtained in the S2;

s4, dividing the second target sampling rate M' into N second target sub-bands through a filter bank, and determining the width of the second target sub-bands;

s5, grouping the N second target sub-bands according to the bark scale to obtain a plurality of second target sub-band groups;

s6, reconstructing and synthesizing the second target subband groups obtained in the S5 and the Bach frequency band corresponding to the second target subband groups through an inverse filter group to form a plurality of corresponding third target signals;

s7, playing back a plurality of third target signals through different speaker units.

2. A novel bass playback method as claimed in claim 1, wherein the step S2 includes the following sub-steps:

s2-1, dividing the resampled first target sampling rate M into N second target sub-bands with equal width by using a filter bank, wherein the value of the second target sub-band needs to look at the highest bass frequency point and the bark scale, and the frequency width of the second target sub-band is ensured to correspond to the width of 0.5 to 1 bark frequency band;

s2-2, wherein N is calculated by using the input audio highest bass frequency point and the frequency width of the second target subband, the formula of N is: n = M ÷ 2 ÷ frequency width;

s2-3, the second target sampling rate is M ', the calculation formula is M' = frequency bandwidth of the second target subband N x 2, where 2 in the calculation formula is that the highest frequency of the signal is one half of the sampling rate according to the nyquist sampling theorem, and therefore, it is necessary to multiply 2 in the calculation formula.

3. A novel bass playback method as claimed in claim 1, wherein the filter banks in S2 and S4 both use perfectly reconstructed filter banks.

4. The new bass playback method as claimed in claim 1, wherein the value range of N is determined as N being greater than or equal to 2 and being a power of 2 according to the theory of a perfectly reconstructed filter bank, and whether N meets the above requirement is determined according to the value obtained in S3, if so, the subsequent steps are continued, and if not, on the basis of the value obtained in S3, the value of the power of 2 which is greater than N and close to N is reselected and determined as N again.

5. A novel bass playback method as claimed in claim 1, wherein the step of S6 employs a perfectly reconstructed inverse filter bank.

6. The utility model provides a novel bass playback device, its characterized in that, includes a plurality of speaker unit, linear audio input terminal, ADC module, resampling module and treater, the speaker unit passes through DAC module and processor module electric connection, linear audio input terminal and ADC module electric connection, ADC module and resampling module electric connection, resampling module and treater electric connection, the treater is including the counter module who is used for implementing filter bank subband quantity to calculate, filter bank module, subband grouping module that can perfect reconsitution and the reverse filter bank module that can perfect reconsitution.

Technical Field

The invention relates to the technical field of bass playback, in particular to a novel bass playback method and device.

Background

With the development of technology, people's requirements for music playback experience become higher and higher, and bass sound becomes more and more popular. At present, various large-sound manufacturers are releasing different grades of n.1 combination sound, such as 2.1 sound for desktop, 5.1 and 7.1 sound for home theater, and the like. In these sounds, the number before the decimal point, for example, 2 in 2.1, 5 in 5.1, represents the number of the middle-high sounds, and the number after the decimal point represents the number of the bass sounds, for example, 2.1 sounds represent 2 middle-high sounds (one is a left channel and one is a right channel) and 1 subwoofer sound, and dividing the high, middle and low sounds and playing back the sounds by different sounds is a method capable of effectively improving the playback fidelity, especially playing back the low sounds by using one sound alone.

At present, the conventional practice in the field is to add a frequency division module to a signal amplification module of a sound, divide an input audio frequency according to a fixed frequency point to obtain a high frequency, a medium frequency and a low frequency, and respectively send the high frequency, the medium frequency and the low frequency to different sounds for playback. The frequency point generally selected by the low-frequency division is 150-250 Hz, so that although the playback fidelity which is obviously improved as a whole can be obtained, according to the theory of Barker scale in the field of audio digital signal processing, at least one Barker frequency band exists in the interval of 150-250 Hz, namely at least two Barker frequency bands exist in the interval of 0-250 Hz, which means that when people listen to bass sound with 150-250 Hz as the frequency division point, at least two sound signals (at least 2 Barker frequency bands exist from 0-250 Hz) need to be obviously perceived. The lower the frequency of the sound signal, the greater the interference generated to the speaker by the pairwise intermodulation, which finally results in the occurrence of serious distortion or serious unbalanced frequency response of the speaker. Therefore, in the current n.1 sound of each major manufacturer, although the fidelity of sound in the mid-high frequency band is sufficiently good, the fidelity of sound in the low frequency band and even in the ultra-low frequency band is poor.

Disclosure of Invention

The invention aims to provide a novel bass playback method and a novel bass playback device, which solve the problem that the fidelity of bass sound playback is not good enough.

The invention discloses a novel bass playback method and a novel bass playback device, which adopt the technical scheme that:

a novel bass playback method, comprising the steps of:

s1, sampling the input audio signal to a first target sampling rate M, wherein the first target sampling rate is twice of the highest low sound frequency point of the input audio;

s2, calculating by adopting a filter bank, determining a second target subband width, N second target subband quantities and calculating to obtain a second target sampling rate M' according to the first target sampling rate M sampled in S1;

s3, sampling the first target sampling rate M to a second target sampling rate M 'according to the second target sampling rate M' obtained in the S2;

s4, dividing the second target sampling rate M' into N second target sub-bands through a filter bank, and determining the width of the second target sub-bands;

s5, grouping the N second target sub-bands according to the bark scale to obtain a plurality of second target sub-band groups;

s6, reconstructing and synthesizing the second target subband groups obtained in the S5 and the Bach frequency band corresponding to the second target subband groups through an inverse filter group to form a plurality of corresponding third target signals;

s7, playing back a plurality of third target signals through different speaker units.

Preferably, the step S2 includes the following substeps:

s2-1, dividing the resampled first target sampling rate M into N second target sub-bands with equal width by using a filter bank, wherein the value of the second target sub-band needs to look at the highest bass frequency point and the bark scale, and the frequency width of the second target sub-band is ensured to correspond to the width of 0.5 to 1 bark frequency band;

s2-2, wherein N is calculated by using the input audio highest bass frequency point and the frequency width of the second target subband, the formula of N is: n = M ÷ 2 ÷ frequency width;

s2-3, the second target sampling rate is M ', the calculation formula is M' = frequency bandwidth of the second target subband N x 2, where 2 in the calculation formula is that the highest frequency of the signal is one half of the sampling rate according to the nyquist sampling theorem, and therefore, it is necessary to multiply 2 in the calculation formula.

Preferably, the filter banks in S2 and S4 each employ a perfectly reconstructed filter bank.

As a preferable scheme, the value range of N is determined to be N greater than or equal to 2 and a power of 2 according to the theory of a perfectly reconstructed filter bank, whether N meets the above requirement is judged according to the value obtained in S3, if N meets the requirement, the subsequent steps are continued, and if N does not meet the requirement, the power of 2 value greater than N and close to N is reselected on the basis of the value obtained in S3, and N is determined again.

Preferably, a perfectly reconstructed inverse filter bank is used in step S6.

The utility model provides a novel bass playback device, includes a plurality of speaker unit, linear audio input terminal, ADC module, resampling module and treater, the speaker unit passes through DAC module and processor module electric connection, linear audio input terminal and ADC module electric connection, ADC module and resampling module electric connection, resampling module and treater electric connection, the treater is including the counter filter bank module that is used for implementing the calculation module of filter bank subband quantity, can perfect reconsitution's filter bank module, subband group module and can perfect reconsitution.

The novel bass playback method disclosed by the invention has the beneficial effects that: the method comprises the steps of sampling an input audio trumpet to a first target sampling rate, adjusting and calculating according to the first target sampling rate to obtain a proper second target sampling rate, dividing the second target sampling rate through a filter bank, carrying out reconstruction synthesis by combining a bark scale and an inverse filter bank to form a plurality of third target signals, and playing back the third target signals through different loudspeakers, so that the bass sound playback has better fidelity.

Drawings

Fig. 1 is a flow chart of a novel bass playback method of the present invention.

Fig. 2 is a table of frequency ranges of a conventional bach band.

Fig. 3 is a schematic diagram of a novel bass playback apparatus of the present invention.

Detailed Description

The invention will be further elucidated and described with reference to the embodiments and drawings of the specification:

referring to fig. 1, a novel bass playback method includes the following steps:

and S1, sampling the input audio signal to a first target sampling rate M, wherein the first target sampling rate is twice of the highest and lowest frequency points of the input audio.

And S2, calculating by using a filter bank, determining a second target subband width, N second target subband quantities and calculating to obtain a second target sampling rate M' according to the first target sampling rate M sampled in S1.

The step S2 includes the following substeps:

and S2-1, dividing the resampled first target sampling rate M into N second target sub-bands with equal widths by using a filter bank, wherein the values of the second target sub-bands need to look at the highest bass frequency point and the bark scale, and the frequency width of the second target sub-bands can be ensured to correspond to the width of 0.5 to 1 bark frequency band.

S2-2, wherein N is calculated by using the input audio highest bass frequency point and the frequency width of the second target subband, the formula of N is: n = M ÷ 2 ÷ frequency width.

S2-3, the second target sampling rate is M ', the calculation formula is M' = frequency bandwidth of the second target subband N x 2, where 2 in the calculation formula is that the highest frequency of the signal is one half of the sampling rate according to the nyquist sampling theorem, and therefore, it is necessary to multiply 2 in the calculation formula.

S3, sampling the first target sampling rate M to the second target sampling rate M 'according to the second target sampling rate M' obtained in S2.

S4, the second target sampling rate M' is divided by the filter bank, divided into N second target subbands, and the width of the second target subbands is determined.

And S5, grouping the N second target sub-bands according to the bark scale to obtain a plurality of second target sub-band groups.

S6, the second target subband groups and the corresponding bach band obtained in S5 are reconstructed and synthesized by an inverse filter group to form a plurality of third target signals.

S7, playing back a plurality of third target signals through different speaker units.

In the above solutions, the filter banks in S2 and S4 both use a perfectly reconstructed filter bank, which is a prior art and therefore is not an improvement of the present solution, and therefore is not described herein, and the perfectly reconstructed filter bank is not limited, and in the specific implementation, pqf (poly phase quadrature filter), qmf (quadrature Mirror filters), MDCT, or other polyphase filters may be selected according to actual situations. The present embodiment uses a perfectly reconstructable pqf (phase resolution filter) filter bank to perform subband splitting, and uses a perfectly reconstructable ipqf (inverse phase resolution filter) inverse filter bank to perform subband signal synthesis.

And the value range of N is determined to be that N is more than or equal to 2 and is the power of 2 according to the theory of a perfectly reconstructed filter bank, whether the N meets the requirements or not is judged according to the value obtained by S3, if the N meets the requirements, the subsequent steps are continued, and if the N does not meet the requirements, the power of 2 value which is more than N and is close to N is reselected on the basis of the value obtained by S3, and the N is determined again.

The above step S6 uses a perfectly reconstructed inverse filter bank adapted to the perfectly reconstructed filter bank used in S2 and S4.

If the sampling rate of the input signal is 48000Hz, the bass frequency of the audio configuration is 250Hz, and the first target sampling rate is the sampling rate of the input 48000Hz signal, which needs to be resampled to 500Hz here to eliminate the middle and high frequency signals, and only the bass signal is retained.

Then, a perfectly reconfigurable filter bank is used to divide the resampled signal into N second target subbands with equal widths, where N is greater than or equal to 2 and is a power of 2, a value of N specifically needs to look at a highest bass frequency point and a bark scale, and it is to be ensured that a frequency width of a subband may correspond to a width of 1 or half of a bark band, please refer to fig. 2, in a frequency interval less than or equal to 500Hz, a width of each bark frequency band is 100Hz, and therefore a subband width should be 50Hz or 100 Hz.

If the maximum bass frequency point in this embodiment is 250Hz, if 100Hz is adopted for each sub-band, then N is 3, the frequency range of sub-band 1 is 0-100 Hz, the frequency range of sub-band 2 is 100-200 Hz, the frequency range of sub-band 3 is 200-300 Hz, if 50Hz is adopted for each sub-band, then N is 5, the frequency range of sub-band 1 is 0-50 Hz, the frequency range of sub-band 2 is 50-100 Hz, the frequency range of sub-band 3 is 100-150 Hz, the frequency range of sub-band 4 is 150-200 Hz, and the frequency range of sub-band 5 is 200-250 Hz, and obviously, the width of each sub-band selected as 50Hz can be closer to the maximum bass frequency point. And in practice, the 50Hz width is selected unless the 100Hz width is preferred based on reducing system resource consumption or load considerations.

At this time, the highest bass frequency point and the subband width are used to calculate N, N =250Hz/50Hz =5, however N =5 is not allowed, which does not meet the above requirements for N, and therefore only 500Hz signals can be resampled again, and the algorithm of the second target sampling rate M ' is M ' =50 × N2, where 50 is the selected frequency subband width 50Hz, and 2 is the highest frequency of the signal according to the nyquist sampling theorem half the sampling rate, so that the frequency conversion sampling rate needs to be multiplied by 2, N can only be equal to or greater than 5, and N =5, 6, 7 are all powers other than 2, so N is selected to be 8, 8 is a power close to 5 and 2, i.e. M ' =50 × 8 =800Hz, and therefore the resampled 500Hz signals need to be resampled to 800Hz here.

Optimization of the 500Hz resampling of the first step directly to 800Hz cannot be considered, because the purpose of the first step resampling is mainly to filter out signals above 250Hz without affecting the phase.

Constructing a perfectly reconstructed filter group with N =8 to divide the frequency of a signal with a sampling rate of 800Hz to obtain 8 second target sub-bands in total, wherein the frequency of the first sub-band is 0-50 Hz, the frequency of the second sub-band is 50-100 Hz, the frequency of the third sub-band is 100-150 Hz, the frequency of the fourth sub-band is 150-200 Hz, the frequency of the fifth sub-band is 200-250 Hz, the frequency of the sixth sub-band is 250-300 Hz, the frequency of the seventh sub-band is 300-350 Hz, and the frequency of the eighth sub-band is 350-400 Hz.

Then, according to the bark scale, starting from 0Hz to 250Hz, 250Hz being the highest bass frequency point, and taking bark bands as units, the frequency sub-bands divided above are grouped, namely bark band 1 is corresponding to a second target sub-band 1 and a second target sub-band 2 from 0 to 100Hz in frequency, bark band 2 is corresponding to a second target sub-band 3 and a second target sub-band 4 from 100 to 200Hz in frequency, and bark band 3 is corresponding to a second target sub-band 5 and a second target sub-band 6 from 200Hz to 300Hz in frequency.

Finally, the above grouped subbands are reconstructed and synthesized by using a perfectly reconstructed inverse filter group in sequence, that is, the subband group 1 reconstructs the synthesized signal a from the barker band 1, the second target subband 1 and the second target subband 2, the subband group 2 reconstructs the synthesized signal B from the barker band 2, the second target subband 3 and the second target subband 4, and the subband group 3 reconstructs the synthesized signal C from the barker band 3, the second target subband 5 and the second target subband 6. The resulting signals A, B and C were each played back using 3 different speakers.

The utility model provides a novel bass playback device, includes a plurality of speaker unit, linear audio input terminal, ADC module, resampling module and treater, the speaker unit passes through DAC module and processor module electric connection, linear audio input terminal and ADC module electric connection, ADC module and resampling module electric connection, resampling module and treater electric connection, the treater is including the counter filter bank module that is used for implementing the calculation module of filter bank subband quantity, can perfect reconsitution's filter bank module, subband group module and can perfect reconsitution.

Referring to fig. 3, the linear audio input terminal is configured to receive an input audio signal, and the ADC module is configured to convert an analog signal of the linear audio input into a digital signal, and resample the digital signal converted by the ADC to a first target sampling rate through the resampling module. And then, a calculation module in the processor calculates the number of second target subbands and a second target sampling rate, a filter bank module divides the second target subbands to obtain second target subband signals, a subband grouping module groups the second target subband signals to obtain a second target subband group according to the bark scale, and an inverse filter bank module reconstructs and synthesizes the second target subband group to obtain a third target signal. And will be played back from different loudspeaker units via the DNC module and the power amplifier circuit.

The invention provides a novel bass playback method, which comprises the steps of sampling an input audio trumpet to a first target sampling rate, adjusting and calculating according to the first target sampling rate to obtain a proper second target sampling rate, dividing the frequency of the second target sampling rate through a filter bank, carrying out reconstruction synthesis by combining a bark scale and an inverse filter bank to form a plurality of third target signals, and playing back the plurality of third target signals through different loudspeakers, thereby ensuring better fidelity of bass playback.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the protection scope of the present invention, although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.