CN113518286A - Reverberation processing method and device for audio signal, electronic equipment and storage medium - Google Patents
Reverberation processing method and device for audio signal, electronic equipment and storage medium Download PDFInfo
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- CN113518286A CN113518286A CN202110732044.3A CN202110732044A CN113518286A CN 113518286 A CN113518286 A CN 113518286A CN 202110732044 A CN202110732044 A CN 202110732044A CN 113518286 A CN113518286 A CN 113518286A
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Abstract
The invention relates to the technical field of signal processing, and discloses a reverberation processing method and device of an audio signal, electronic equipment and a storage medium. The reverberation processing method of the audio signal comprises the following steps: acquiring an original audio signal to be processed; inputting the original audio signal into a preset multi-stage reverberation effect device to obtain a first path of echo signal and a second path of echo signal corresponding to each stage; wherein, the echo output of each level is used as the input of the next level; mixing the first path of echo signal corresponding to each stage with the original audio signal to obtain a corresponding first path of reverberation audio signal; and mixing the second path of echo signal corresponding to each stage with the original audio signal to obtain a corresponding second path of reverberation audio signal. The invention improves the reverberation effect of the audio signal.
Description
Technical Field
The present invention relates to the field of signal processing technologies, and in particular, to a reverberation processing method and apparatus for an audio signal, an electronic device, and a storage medium.
Background
When music is played, the reverberation sound effect is the sound effect when the simulated sound is reflected back through each wall surface in a room and then is superposed with the current sound, and a reverberator is usually used for realizing the reverberation sound effect. The existing reverberator generates reverberation with less obvious change of space feeling, the early, middle and later reflections of the reverberation are not coherent and complete enough, and the reverberation effect is not real and natural enough.
Therefore, how to improve the reverberation effect becomes an urgent problem to be solved.
Disclosure of Invention
The invention mainly aims to solve the technical problem that the existing reverberator is poor in reverberation effect.
The first aspect of the present invention provides a method for processing reverberation of an audio signal, where the method for processing reverberation of an audio signal includes:
acquiring an original audio signal to be processed;
inputting the original audio signal into a preset multi-stage reverberation effect device to obtain a first path of echo signal and a second path of echo signal corresponding to each stage; wherein, the echo output of each level is used as the input of the next level;
mixing the first path of echo signal corresponding to each stage with the original audio signal to obtain a corresponding first path of reverberation audio signal; and mixing the second path of echo signal corresponding to each stage with the original audio signal to obtain a corresponding second path of reverberation audio signal.
Optionally, in a first implementation manner of the first aspect of the present invention, each stage of the multi-stage reverberation effector includes a nested all-pass filter and a delay filter connected in series, and the inputting the original audio signal into a preset multi-stage reverberation effector to obtain a first path of echo signal and a second path of echo signal corresponding to each stage includes:
taking the original audio signal and the echo output of the previous stage as current-stage input, and processing the current-stage input by using a nested all-pass filter to obtain a first path of echo signal corresponding to the current stage;
and inputting the first path of echo signal corresponding to the current stage into the delay filter of the current stage, and outputting the second path of echo signal corresponding to the current stage.
Optionally, in a second implementation manner of the first aspect of the present invention, each stage of the multistage reverberation effector further includes a gain controller connected in series with the delay filter, where a parameter of the gain controller of each stage is adjustable, the inputting the first echo signal corresponding to the current stage into the delay filter of the current stage, and after outputting the second echo signal corresponding to the current stage, the method further includes:
and inputting the second path of echo signal corresponding to the current level into the gain controller of the current level to obtain the echo output corresponding to the current level.
Optionally, in a third implementation manner of the first aspect of the present invention, the multi-stage reverberation effector further includes a pre-delay device, and taking the original audio signal and an echo output of a previous stage as current-stage inputs includes:
inputting the original audio signal into the pre-delay device to obtain a corresponding input signal;
and taking the input signal and the echo output of the previous stage as the input of the current stage.
Optionally, in a fourth implementation manner of the first aspect of the present invention, the nested all-pass filter includes a first all-pass filter, a second all-pass filter, a low-pass filter, and a low-frequency oscillator, the low-pass filter is connected in series with the first all-pass filter, a series branch formed by the low-pass filter and the first all-pass filter is connected in parallel with the second all-pass filter, and the low-frequency oscillator is connected in series with the second all-pass filter.
Optionally, in a fifth implementation manner of the first aspect of the present invention, the low-frequency oscillator modulates the second all-pass filter to generate a fractional delay length, and the method further includes:
and carrying out nonlinear interpolation on the delay length of the decimal by using an all-pass filter to obtain the corresponding delay length of the integer.
Optionally, in a sixth implementation manner of the first aspect of the present invention, the first path of echo signal corresponding to each stage is mixed with the original audio signal to obtain a corresponding first path of reverberation audio signal; and mixing the second path of echo signal corresponding to each stage with the original audio signal to obtain a corresponding second path of reverberation audio signal, wherein the step of mixing the second path of echo signal with the original audio signal comprises the following steps:
the first echo signal corresponding to each stage is output in parallel in a corresponding proportion through the corresponding gain controller, and is mixed with the original audio signal to obtain a corresponding first reverberation audio signal;
and the second path of echo signals corresponding to each stage are output in parallel in a corresponding proportion through the corresponding gain controllers, and are mixed with the original audio signals to obtain corresponding second path of reverberation audio signals.
The second aspect of the present invention provides an apparatus for reverberation processing of an audio signal, the apparatus comprising:
the acquisition module is used for acquiring an original audio signal to be processed;
the first processing module is used for inputting the original audio signal into a preset multi-stage reverberation effect device to obtain a first path of echo signal and a second path of echo signal corresponding to each stage; wherein, the echo output of each level is used as the input of the next level;
the second processing module is used for mixing the first path of echo signal corresponding to each stage with the original audio signal to obtain a corresponding first path of reverberation audio signal; and mixing the second path of echo signal corresponding to each stage with the original audio signal to obtain a corresponding second path of reverberation audio signal.
Optionally, in a first implementation manner of the second aspect of the present invention, each stage of the multi-stage reverberation effector includes a nested all-pass filter and a delay filter connected in series, and the first processing module is specifically configured to:
taking the original audio signal and the echo output of the previous stage as current-stage input, and processing the current-stage input by using a nested all-pass filter to obtain a first path of echo signal corresponding to the current stage;
and inputting the first path of echo signal corresponding to the current stage into the delay filter of the current stage, and outputting the second path of echo signal corresponding to the current stage.
Optionally, in a second implementation manner of the second aspect of the present invention, each stage of the multi-stage reverberation effector further includes a gain controller connected in series with the delay filter, a parameter of the gain controller of each stage is adjustable, and the first processing module is further specifically configured to:
and inputting the second path of echo signal corresponding to the current level into the gain controller of the current level to obtain the echo output corresponding to the current level.
Optionally, in a third implementation manner of the second aspect of the present invention, the multi-stage reverberation effector further includes a pre-delay device, and the first processing module is further specifically configured to:
inputting the original audio signal into the pre-delay device to obtain a corresponding input signal;
and taking the input signal and the echo output of the previous stage as the input of the current stage.
Optionally, in a fourth implementation manner of the second aspect of the present invention, the nested all-pass filter includes a first all-pass filter, a second all-pass filter, a low-pass filter, and a low-frequency oscillator, the low-pass filter is connected in series with the first all-pass filter, a series branch formed by the low-pass filter and the first all-pass filter is connected in parallel with the second all-pass filter, and the low-frequency oscillator is connected in series with the second all-pass filter.
Optionally, in a fifth implementation manner of the second aspect of the present invention, the apparatus for processing reverberation of the audio signal further includes:
and the second processing module is used for carrying out nonlinear interpolation on the delay length of the decimal by using an all-pass filter to obtain the corresponding delay length of the integer.
Optionally, in a sixth implementation manner of the second aspect of the present invention, the second processing module is specifically configured to:
the first echo signal corresponding to each stage is output in parallel in a corresponding proportion through the corresponding gain controller, and is mixed with the original audio signal to obtain a corresponding first reverberation audio signal;
and the second path of echo signals corresponding to each stage are output in parallel in a corresponding proportion through the corresponding gain controllers, and are mixed with the original audio signals to obtain corresponding second path of reverberation audio signals.
A third aspect of the present invention provides an electronic apparatus, comprising: a memory and at least one processor, the memory having instructions stored therein;
the at least one processor invokes the instructions in the memory to cause the electronic device to perform a reverberation processing method of an audio signal as described in any one of the above.
A fourth aspect of the present invention provides a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements a method of reverberation processing of an audio signal as defined in any one of the above.
In the technical scheme provided by the invention, an original audio signal is obtained, the original audio signal is input into a preset multi-stage reverberation effect device, a first path of echo signal and a second path of echo signal corresponding to each stage are obtained, wherein for the multi-stage reverberation effect device, the echo output of each stage is used as the input of the next stage, multi-level and multi-azimuth echo effects are added, the first path of echo signal corresponding to each stage and the original audio signal are mixed to obtain a corresponding first path of reverberation audio signal, the second path of echo signal corresponding to each stage and the original audio signal are mixed to obtain a corresponding second path of reverberation audio signal, the first path of reverberation audio signal and the second path of reverberation audio signal can comprehensively simulate the early, middle and late reflections of reverberation, and the reverberation effect is real and natural, so the reverberation effect is improved, thereby improving the user experience.
Drawings
Fig. 1 is a schematic diagram of a first embodiment of a reverberation processing method of an audio signal according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a reverberation multi-stage framework according to an embodiment of the present invention;
FIG. 3 is a diagram illustrating a structure of a multi-node output framework for reverberation according to an embodiment of the present invention;
FIG. 4 is a diagram of a nested all-pass filter according to an embodiment of the present invention;
FIG. 5 is a schematic diagram of an all-pass filter according to an embodiment of the present invention;
fig. 6 is a schematic diagram of a first embodiment of the reverberation processing device of the audio signal according to the embodiment of the present invention;
fig. 7 is a schematic diagram of a second embodiment of the reverberation processing device of the audio signal according to the embodiment of the present invention;
fig. 8 is a schematic diagram of an embodiment of an electronic device in an embodiment of the invention.
Detailed Description
The embodiment of the invention provides a method, a device, electronic equipment and a storage medium for reverberation processing of an audio signal, wherein an original audio signal is input into a preset multi-stage reverberation effect device to obtain a first multi-stage echo signal and a second multi-stage echo signal, the first multi-stage echo signal and the original audio signal are mixed to obtain a corresponding first reverberation audio signal, the second multi-stage echo signal and the original audio signal are mixed to obtain a corresponding second reverberation audio signal, the first reverberation audio signal and the second reverberation audio signal can comprehensively simulate early, middle and late reflections of reverberation, and the reverberation effect is real and natural, so that the reverberation effect is improved. The terms "first," "second," "third," "fourth," and the like in the description and in the claims, as well as in the drawings, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It will be appreciated that the data so used may be interchanged under appropriate circumstances such that the embodiments described herein may be practiced otherwise than as specifically illustrated or described herein. Furthermore, the terms "comprises," "comprising," or "having," and any variations thereof, are intended to cover non-exclusive inclusions, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
For the sake of understanding, the following describes a specific flow of an embodiment of the present invention, and referring to fig. 1, a first embodiment of a reverberation processing method for an audio signal in an embodiment of the present invention includes:
101. acquiring an original audio signal to be processed;
for example, taking music playing as an example, the audio corresponding to the music to be played is the original audio signal. For convenience of description, the original audio signal is hereinafter labeled as x (n). For music to be played, an original audio signal x (n) corresponding to the music is obtained.
For another example, a voice signal of a user is collected by a voice collecting device such as a microphone, the collected voice signal is converted into a digital signal, and the obtained digital signal is used as an original audio signal x (n).
102. Inputting the original audio signal into a preset multi-stage reverberation effect device to obtain a first path of echo signal and a second path of echo signal corresponding to each stage; wherein, the echo output of each level is used as the input of the next level;
in this embodiment, in order to improve the reverberation effect, a corresponding multi-stage reverberation effect device is provided, and the multi-stage reverberation effect device has a reverberation multi-stage frame structure and a reverberation multi-node output frame structure. Wherein each stage of the multi-stage reverberation effector in the reverberant multi-stage framework structure comprises a nested all-pass filter (MN _ APF) and a Delay filter (Delay) in series.
And inputting the original audio signal x (n) into the multi-stage reverberation effect device to obtain a first echo signal and a second echo signal corresponding to each stage. For convenience of description, the first echo signal corresponding to the i-th level is referred to as yil (n), and the second echo signal is referred to as yir (n).
Wherein the echo output of each stage is used as the input of the next stage. That is, the echo output of the ith stage serves as the input of the (i +1) th stage. Optionally, the reverberation multi-stage frame structure is a reverberation multi-stage closed frame structure, and an echo output of the last stage is used as an input of the first stage.
Therefore, the input of each stage comprises the original audio signal x (n) and the echo output of the previous stage, thereby increasing the echo effect of multiple levels and multiple directions.
In an embodiment, step 102 specifically includes:
(1) taking the original audio signal and the echo output of the previous stage as current-stage input, and processing the current-stage input by using a nested all-pass filter to obtain a first path of echo signal corresponding to the current stage;
(2) and inputting the first path of echo signal corresponding to the current stage into the delay filter of the current stage, and outputting the second path of echo signal corresponding to the current stage.
The corresponding second echo signal yir (n) is obtained through the Delay filter (Delay), and the Delay filter (Delay) can provide echo signals at more positions (such as y1R (n), y2R (n), etc.) for output.
In an embodiment, each stage of the multi-stage reverb effector further comprises a gain controller (G) in series with the Delay filter (Delay), wherein the parameters of the gain controller (G) of each stage are adjustable. The gain controller (G) can control the echo output intensity corresponding to each level, and further influences the duration time of reverberation, thereby simulating the reverberation effect of different scenes.
Inputting the first path of echo signal corresponding to the current stage into the delay filter of the current stage, and after outputting the second path of echo signal corresponding to the current stage, the method further includes:
(3) and inputting the second path of echo signal corresponding to the current level into the gain controller of the current level to obtain the echo output corresponding to the current level.
That is, after the second path of echo signal yir (n) corresponding to the ith stage is input into the gain controller Gi of the ith stage, the echo corresponding to the ith stage is output.
In an embodiment, the multi-stage reverberation effector further comprises a pre-delay (preDelay) device, the pre-delay being the time between directly hearing the sound source and hearing the echo of the first reflection, the pre-delay determining the size of the current space.
The step (1) specifically comprises:
(11) inputting the original audio signal into the pre-delay device to obtain a corresponding input signal;
(12) and taking the input signal and the echo output of the previous stage as the input of the current stage.
That is, a pre-delay device (pre delay) is disposed before the nested all-pass filter (MN _ APF), and before the original audio signal x (n) is input into the nested all-pass filter (MN _ APF), the original audio signal x (n) is input into the pre-delay device (pre delay) to obtain an input signal corresponding to the original audio signal x (n). And taking the input signal corresponding to the original audio signal x (n) and the echo output of the previous stage as the input of the current stage. That is, the input of each stage includes both the input signal corresponding to the original audio signal x (n) and the echo output of the previous stage.
For example, as shown in fig. 2, the multi-stage reverb effector includes a 4-stage closed frame in which 4 nested all-pass filters (MN _ APF1, MN _ APF2, MN _ APF1, MN _ APF4) are connected in series and used in a hierarchical loop, with a pre-delay (predilay) preceding each stage, corresponding to one horizontal branch. In the first horizontal branch, a nested all-pass filter (MN _ APF1) is followed by a corresponding Delay filter (Delay1) and gain controller (G1); in the second horizontal branch, the nested all-pass filter (MN _ APF2) is followed by a corresponding Delay filter (Delay2) and gain controller (G2); in the third horizontal branch, a nested all-pass filter (MN _ APF3) is followed by a corresponding Delay filter (Delay3) and gain controller (G3); in the fourth horizontal branch, a nested all-pass filter (MN _ APF4) is followed by a corresponding Delay filter (Delay4) and gain controller (G4).
Inputting the original audio signal x (n) into a pre-delay device (preDelay) to obtain an input signal corresponding to the original audio signal x (n). An input signal corresponding to an original audio signal x (n) and an echo output of a fourth stage (namely, a fourth horizontal branch) are used as first-stage input, the input signal and the echo output are mixed and input into a nested all-pass filter (MN _ APF1) of a first stage (namely, a first horizontal branch), the first-stage nested all-pass filter (MN _ APF1) is used for processing to obtain a first-path echo signal y1L (n) corresponding to the first stage, the first-path echo signal is input into a Delay filter (Delay1) of the first stage, and a second-path echo signal y1R (n) corresponding to the first stage is output. The second echo signal y1R (n) is input into the gain controller G1 of the first stage, and then the echo output corresponding to the first stage is output.
Taking the echo output corresponding to the first stage and the input signal corresponding to the original audio signal x (n) as the second stage input, mixing and inputting the input signal into a nested all-pass filter (MN _ APF2) of the second stage, processing the input signal by a nested all-pass filter (MN _ APF2) of the second stage to obtain a first path of echo signal y2L (n) corresponding to the second stage, inputting the first path of echo signal to a Delay filter (Delay2) of the second stage, and outputting a second path of echo signal y2R (n) corresponding to the second stage. The second echo signal y2R (n) is input into the gain controller G2 of the second stage, and then the echo output corresponding to the second stage is output.
Taking the echo output corresponding to the second stage and the input signal corresponding to the original audio signal x (n) as the third-stage input, mixing and inputting the input signal into a nested all-pass filter (MN _ APF3) of the third stage, processing the input signal by the nested all-pass filter (MN _ APF3) of the third stage to obtain a first echo signal y3L (n) corresponding to the third stage, inputting the first echo signal to a Delay filter (Delay3) of the third stage, and outputting a second echo signal y3R (n) corresponding to the third stage. And the second path of echo signal y3R (n) is input into the gain controller G3 of the third stage, and then the echo output corresponding to the third stage is output.
Taking the echo output corresponding to the third stage and the input signal corresponding to the original audio signal x (n) as fourth-stage input, mixing and inputting the input signal into a nested all-pass filter (MN _ APF4) of the fourth stage, processing the input signal by the nested all-pass filter (MN _ APF4) of the fourth stage to obtain a first echo signal y4L (n) corresponding to the fourth stage, inputting the first echo signal to a Delay filter (Delay4) of the fourth stage, and outputting a second echo signal y4R (n) corresponding to the fourth stage. The second echo signal y4R (n) is input into the gain controller G4 of the fourth stage, and then the echo output corresponding to the fourth stage is output.
103. Mixing the first path of echo signal corresponding to each stage with the original audio signal to obtain a corresponding first path of reverberation audio signal; mixing the second path of echo signal corresponding to each stage with the original audio signal to obtain a corresponding second path of reverberation audio signal;
in an embodiment, step 103 specifically includes:
(1) the first echo signal corresponding to each stage is output in parallel in a corresponding proportion through the corresponding gain controller, and is mixed with the original audio signal to obtain a corresponding first reverberation audio signal;
(2) and the second path of echo signals corresponding to each stage are output in parallel in a corresponding proportion through the corresponding gain controllers, and are mixed with the original audio signals to obtain corresponding second path of reverberation audio signals.
For example, as shown in fig. 3, y1L (n), y2L (n), y3L (n), and y4L (n) respectively correspond to gain controllers g1, g2, g3, and g4, and y1R (n), y2R (n), y3R (n), and y4R (n) respectively correspond to gain controllers g5, g6, g7, and g 8.
And (3) outputting y1L (n), y2L (n), y3L (n) and y4L (n) in parallel in a corresponding proportion through corresponding gain controllers g1, g2, g3 and g4, and mixing the output signals with the original audio signal x (n) to obtain a corresponding first path reverberation audio signal yL (n).
And (3) outputting y1R (n), y2R (n), y3R (n) and y4R (n) in parallel in a corresponding proportion through corresponding gain controllers g5, g6, g7 and g8, and mixing the output signals with the original audio signal x (n) to obtain a corresponding second channel of reverberation audio signal yR (n).
The first path of echo signal and the second path of echo signal corresponding to each level, such as y1L (n) and y1R (n), are output in parallel in a specific proportion through the corresponding gain controllers, so that commonly-called 'wet sound' is obtained, early, middle and late reflections of reverberation can be comprehensively simulated, and the reverberation effect is real and natural. The original audio signals x (n), commonly called "dry sound", are mixed and weighted by respective post-gain controllers (such as wet and dry gain controllers in fig. 3) to obtain final output results (yl (n), yr (n)).
In an embodiment, the reverberation output result may be influenced by changing the parameter values of the gain controllers g1, g2 … …. The final reverberation output result can also be influenced by changing the parameter values of the wet and wet gain controllers, namely changing the dry and wet proportion. Moreover, by setting appropriate values for the parameters of the gain controllers g1 and g2 … …, a coloring effect or standing wave that may occur in the echo signal can be avoided.
In the embodiment, the original audio signal is obtained and input into a preset multi-stage reverberation effect device to obtain a first echo signal and a second echo signal corresponding to each stage, wherein, for the multi-stage reverberation effect device, the echo output of each stage is used as the input of the next stage, multi-stage and multi-azimuth echo effects are added, the first path of echo signal corresponding to each stage is mixed with the original audio signal to obtain the corresponding first path of reverberation audio signal, and mixing the second path of echo signal corresponding to each level with the original audio signal to obtain a corresponding second path of reverberation audio signal, wherein the first path of reverberation audio signal and the second path of reverberation audio signal can comprehensively simulate early, middle and late reflections of reverberation, and the reverberation effect is real and natural, so that the reverberation effect is improved, and the user experience is improved.
Referring to fig. 4, in a second embodiment of the reverberation processing method of the audio signal according to the embodiment of the present invention, the nested all-pass filter MN _ APF includes a first all-pass filter APF1, a second all-pass filter APF2, a low-pass filter LPF and a low-frequency oscillator LFO, wherein the low-pass filter LPF is connected in series with the first all-pass filter APF1, a series branch is connected in parallel with the second all-pass filter APF2, and the low-frequency oscillator LFO is connected in series with the second all-pass filter APF 2.
The structures of the first all-pass filter APF1 and the second all-pass filter APF2 are shown in fig. 5, and include a gain controller g, a gain controller-g and a Delay filter Delay. The input signal gets one path of echo signal after Delay filter Delay, the echo signal is mixed with the original signal after gain controller g, and is used as input signal, another path of echo signal is got after gain controller-g, two paths of echo signals are mixed, and output result is got.
The nested all-pass filter MN _ APF has the following advantages:
a. the comb filter is replaced by an all-pass filter. Multiple echoes can be generated with only an all-pass filter and exhibit exponential attenuation in amplitude.
b. The first all-pass filter APF1 is nested within the second all-pass filter APF 2. The number of echoes generated by a single all-pass filter is rare and the echo spacing is fixed. The number of echoes generated by two all-pass filters is greatly increased, and the echo interval is sharply reduced. This not only accumulates more echoes but also enhances the smearing of the sound.
c. The delay filter of the outer second all-pass filter APF2 is modulated using a low frequency oscillator LFO. Although the nested all-pass filter keeps the echo density increasing, the delay length is constant at the outer second all-pass filter APF 2. In order to further make the echo density increase exponentially with the time, the delay filter of the second all-pass filter APF2 is modulated by the low-frequency oscillator LFO, so that the tail effect of the sound is further enhanced in the time domain and the echo density is increased, which is closer to the actual reverberation.
Optionally, the low frequency oscillator LFO has very small frequency and amplitude values to ensure that no significant detuning (harmonic distortion) or chorus effects are produced.
Optionally, the low frequency oscillator modulates the second all-pass filter APF2, and modulates the delay filter of the second all-pass filter APF2, to generate a fractional delay length. And carrying out nonlinear interpolation by using an all-pass filter, and carrying out nonlinear interpolation on the delay length of the decimal form by using the all-pass filter to obtain the corresponding delay length of the integer form so as to avoid high-frequency loss, amplitude and phase distortion and even aliasing of sound.
d. A low pass filter LPF is nested in the feedback loop. The low pass filter LPF can accelerate the attenuation speed of high frequency components in sound and simulate the absorption of the high frequency components of the sound in a real scene, so that a more natural reverberation effect is achieved, and the audibility is more real.
In this embodiment, by designing the nested all-pass filter MN _ APF, one all-pass filter is embedded in the other all-pass filter, and the reverberation effect is better than that of a simple series or parallel connection of two all-pass filters. In addition, a low-pass filter is nested to attenuate the high-frequency components of the sound, and the absorption of the high-frequency components of the sound in a real scene is simulated, so that a more natural reverberation effect is achieved, the hearing sense is more real, and the user experience is improved.
With reference to fig. 6, the method for reverberation processing of an audio signal according to an embodiment of the present invention is described above, and a first embodiment of the apparatus for reverberation processing of an audio signal according to an embodiment of the present invention includes:
an obtaining module 201, configured to obtain an original audio signal to be processed;
the first processing module 202 is configured to input the original audio signal into a preset multi-stage reverberation effector to obtain a first echo signal and a second echo signal corresponding to each stage; wherein, the echo output of each level is used as the input of the next level;
the second processing module 203 is configured to perform mixing processing on the first channel of echo signal corresponding to each stage and the original audio signal to obtain a corresponding first channel of reverberation audio signal; and mixing the second path of echo signal corresponding to each stage with the original audio signal to obtain a corresponding second path of reverberation audio signal.
Optionally, in an embodiment, each stage of the multi-stage reverberation effector includes a nested all-pass filter and a delay filter connected in series, and the first processing module 202 is specifically configured to:
taking the original audio signal and the echo output of the previous stage as current-stage input, and processing the current-stage input by using a nested all-pass filter to obtain a first path of echo signal corresponding to the current stage;
and inputting the first path of echo signal corresponding to the current stage into the delay filter of the current stage, and outputting the second path of echo signal corresponding to the current stage.
Optionally, in an embodiment, each stage of the multi-stage reverberation effector further includes a gain controller connected in series with the delay filter, a parameter of the gain controller of each stage is adjustable, and the first processing module 202 is further specifically configured to:
and inputting the second path of echo signal corresponding to the current level into the gain controller of the current level to obtain the echo output corresponding to the current level.
Optionally, in an embodiment, the multi-stage reverberation effector further includes a pre-delay device, and the first processing module 202 is specifically further configured to:
inputting the original audio signal into the pre-delay device to obtain a corresponding input signal;
and taking the input signal and the echo output of the previous stage as the input of the current stage.
Optionally, in an embodiment, the second processing module 203 is specifically configured to:
the first echo signal corresponding to each stage is output in parallel in a corresponding proportion through the corresponding gain controller, and is mixed with the original audio signal to obtain a corresponding first reverberation audio signal;
and the second path of echo signals corresponding to each stage are output in parallel in a corresponding proportion through the corresponding gain controllers, and are mixed with the original audio signals to obtain corresponding second path of reverberation audio signals.
In the embodiment, the original audio signal is obtained and input into a preset multi-stage reverberation effect device to obtain a first echo signal and a second echo signal corresponding to each stage, wherein, for the multi-stage reverberation effect device, the echo output of each stage is used as the input of the next stage, multi-stage and multi-azimuth echo effects are added, the first path of echo signal corresponding to each stage is mixed with the original audio signal to obtain the corresponding first path of reverberation audio signal, and mixing the second path of echo signal corresponding to each level with the original audio signal to obtain a corresponding second path of reverberation audio signal, wherein the first path of reverberation audio signal and the second path of reverberation audio signal can comprehensively simulate early, middle and late reflections of reverberation, and the reverberation effect is real and natural, so that the reverberation effect is improved, and the user experience is improved.
Referring to fig. 7, in a second embodiment of the reverberation processing device of the audio signal according to the embodiment of the present invention, the nested all-pass filter MN _ APF includes a first all-pass filter APF1, a second all-pass filter APF2, a low-pass filter LPF and a low-frequency oscillator LFO, wherein the low-pass filter LPF is connected in series with the first all-pass filter APF1, a series branch is connected in parallel with the second all-pass filter APF2, and the low-frequency oscillator LFO is connected in series with the second all-pass filter APF 2. The low frequency oscillator LFO modulates the second all-pass filter APF2 to produce a fractional delay length.
The apparatus for reverberation processing of an audio signal further comprises:
and a third processing module 204, configured to perform nonlinear interpolation on the delay length of the fractional expression by using an all-pass filter, so as to obtain a corresponding delay length of an integer expression.
In this embodiment, the fractional delay length is subjected to nonlinear interpolation by using an all-pass filter to obtain a corresponding integer delay length, so as to avoid high-frequency loss, amplitude and phase distortion and even aliasing of sound.
Fig. 6 and 7 describe the reverberation processing device of the audio signal in the embodiment of the present invention in detail from the perspective of the modular functional entity, and the electronic device in the embodiment of the present invention is described in detail from the perspective of the hardware processing.
Fig. 8 is a schematic structural diagram of an electronic device according to an embodiment of the present invention, where the electronic device 800 may have a relatively large difference due to different configurations or performances, and may include one or more processors (CPUs) 810 (e.g., one or more processors) and a memory 820, and one or more storage media 830 (e.g., one or more mass storage devices) storing an application 833 or data 832. Memory 820 and storage medium 830 may be, among other things, transient or persistent storage. The program stored in the storage medium 830 may include one or more modules (not shown), each of which may include a sequence of instructions operating on the electronic device 800. Further, the processor 810 may be configured to communicate with the storage medium 830 and execute a series of instruction operations in the storage medium 830 on the electronic device 800.
The electronic device 800 may also include one or more power supplies 840, one or more wired or wireless network interfaces 850, one or more input-output interfaces 860, and/or one or more operating systems 831, such as Android, Windows Server, Mac OS X, Unix, Linux, FreeBSD, and so forth. Those skilled in the art will appreciate that the electronic device configuration shown in fig. 8 does not constitute a limitation of the electronic device and may include more or fewer components than those shown, or some components may be combined, or a different arrangement of components.
The present invention also provides an electronic device, which includes a memory and a processor, wherein the memory stores computer readable instructions, and the computer readable instructions, when executed by the processor, cause the processor to execute the steps of the reverberation processing method of the audio signal in the above embodiments.
The present invention also provides a computer-readable storage medium, which may be a non-volatile computer-readable storage medium, and which may also be a volatile computer-readable storage medium, having stored therein instructions that, when run on a computer, cause the computer to perform the steps of the method for reverberation processing of an audio signal.
It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a read-only memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.
The above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (10)
1. A method for reverberation processing of an audio signal, comprising:
acquiring an original audio signal to be processed;
inputting the original audio signal into a preset multi-stage reverberation effect device to obtain a first path of echo signal and a second path of echo signal corresponding to each stage; wherein, the echo output of each level is used as the input of the next level;
mixing the first path of echo signal corresponding to each stage with the original audio signal to obtain a corresponding first path of reverberation audio signal; and mixing the second path of echo signal corresponding to each stage with the original audio signal to obtain a corresponding second path of reverberation audio signal.
2. The method of claim 1, wherein each stage of the multi-stage reverberation effector includes a nested all-pass filter and a delay filter connected in series, and the inputting the original audio signal into a preset multi-stage reverberation effector to obtain a first echo signal and a second echo signal corresponding to each stage includes:
taking the original audio signal and the echo output of the previous stage as current-stage input, and processing the current-stage input by using a nested all-pass filter to obtain a first path of echo signal corresponding to the current stage;
and inputting the first path of echo signal corresponding to the current stage into the delay filter of the current stage, and outputting the second path of echo signal corresponding to the current stage.
3. The method as claimed in claim 2, wherein each stage of the multi-stage reverberation effector further includes a gain controller connected in series with the delay filter, and the parameters of the gain controller of each stage are adjustable, and after the first echo signal corresponding to the current stage is input to the delay filter of the current stage and the second echo signal corresponding to the current stage is output, the method further includes:
and inputting the second path of echo signal corresponding to the current level into the gain controller of the current level to obtain the echo output corresponding to the current level.
4. The method as claimed in claim 2, wherein the multi-stage reverberation effector further comprises a pre-delay device, and the outputting the original audio signal and the echo of the previous stage as the current stage input comprises:
inputting the original audio signal into the pre-delay device to obtain a corresponding input signal;
and taking the input signal and the echo output of the previous stage as the input of the current stage.
5. The method of claim 2, wherein the nested all-pass filter comprises a first all-pass filter, a second all-pass filter, a low-pass filter and a low-frequency oscillator, the low-pass filter is connected in series with the first all-pass filter, the series branch is connected in parallel with the second all-pass filter, and the low-frequency oscillator is connected in series with the second all-pass filter.
6. The method of claim 5, wherein modulating the second all-pass filter by the low-frequency oscillator generates a fractional delay length, the method further comprising:
and carrying out nonlinear interpolation on the delay length of the decimal by using an all-pass filter to obtain the corresponding delay length of the integer.
7. The method according to any one of claims 1 to 6, wherein the first path of echo signal corresponding to each stage is mixed with the original audio signal to obtain a corresponding first path of reverberant audio signal; and mixing the second path of echo signal corresponding to each stage with the original audio signal to obtain a corresponding second path of reverberation audio signal, wherein the step of mixing the second path of echo signal with the original audio signal comprises the following steps:
the first echo signal corresponding to each stage is output in parallel in a corresponding proportion through the corresponding gain controller, and is mixed with the original audio signal to obtain a corresponding first reverberation audio signal;
and the second path of echo signals corresponding to each stage are output in parallel in a corresponding proportion through the corresponding gain controllers, and are mixed with the original audio signals to obtain corresponding second path of reverberation audio signals.
8. An apparatus for reverberation processing of an audio signal, comprising:
the acquisition module is used for acquiring an original audio signal to be processed;
the first processing module is used for inputting the original audio signal into a preset multi-stage reverberation effect device to obtain a first path of echo signal and a second path of echo signal corresponding to each stage; wherein, the echo output of each level is used as the input of the next level;
the second processing module is used for mixing the first path of echo signal corresponding to each stage with the original audio signal to obtain a corresponding first path of reverberation audio signal; and mixing the second path of echo signal corresponding to each stage with the original audio signal to obtain a corresponding second path of reverberation audio signal.
9. An electronic device, characterized in that the electronic device comprises: a memory and at least one processor, the memory having instructions stored therein;
the at least one processor invokes the instructions in the memory to cause the electronic device to perform the reverberation processing method of the audio signal as set forth in any of claims 1-7.
10. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out a method of reverberation processing of an audio signal according to any one of claims 1-7.
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