KR20120074303A - Audio signal switching method and device - Google Patents

Abstract

A method and apparatus for switching speech or audio signals are disclosed. The method for switching speech or audio signals weights the first high frequency band signal of the current frame of the speech or audio signal and the second high frequency band signal of the previous M frame of the speech or audio signal when the speech or audio switching occurs. Weighting to obtain a processed first high frequency band signal (101); And synthesizing 102 the processed first high frequency band signal and the first low frequency band signal of the current frame of the speech or audio signal into a wide frequency band signal.

Description

AUDIO SIGNAL SWITCHING METHOD AND DEVICE}

This application claims priority to Chinese Patent Application No. 201010163406.3 filed with the Chinese Patent Office on April 28, 2010, entitled "METHOD AND APPARATUS FOR SWITCHING SPEECH OR AUDIO SIGNALS," the entire contents of which are hereby incorporated by reference. Included in the specification.

The present invention relates to a communication technique, in particular a method and apparatus for switching speech or audio signals.

Currently, during the process of transmitting speech or audio signals over a network, because network conditions can vary, the network intercepts speech or audio signals sent from the encoder to the network with different bit rates. This allows the decoder to decode speech or audio signals having multiple bandwidths from the intercepted bit stream.

In the prior art, since speech or audio signals transmitted over a network have multiple bandwidths, bidirectional switching between narrow frequency speech or audio signals and wide frequency speech or audio signals may occur during the process of transmitting speech or audio signals. Can be. In an embodiment of the invention, the narrow frequency band signal can be switched to a wide frequency band signal with only low frequency band components through up-sampling and low-pass filtering, and wide frequency band speech. Alternatively, the audio signal includes both low frequency band signal components and high frequency band signal components.

In the course of the implementation of the present invention, the inventors have found at least the following problems in the prior art. High-frequency band signal information is available for wide frequency band speech or audio signals, but absent from narrow frequency band speech or audio signals, so that when speech or audio signals of different bandwidths are switched, energy jumps in speech or audio signals. An energy jump occurs, which can make you feel uncomfortable, reducing the quality of the audio signal you receive.

Embodiments of the present invention provide a method and apparatus for switching speech or audio signals that smoothly switch between speech or audio signals between different bandwidths, thereby improving the quality of the audio signal received by the user.

A method for switching a speech or audio signal, wherein M is greater than or equal to 1, and when switching of speech or audio occurs, the first high frequency band signal of the current frame of the speech or audio signal and the previous M frame of the speech or audio signal. Weighting a second high frequency band signal of to obtain a processed first high frequency band signal; And synthesizing the processed first high frequency band signal and the first low frequency band signal of the current frame of the speech or audio signal into a wide frequency band signal.

An apparatus for switching speech or audio signals, wherein M is greater than or equal to 1, and when switching of speech or audio occurs, the first high frequency band signal of the current frame of the speech or audio signal and the previous M frame of the speech or audio signal. A processing module configured to weight the second high frequency band signal of to obtain a processed first high frequency band signal; And a first synthesis module configured to synthesize the processed first high frequency band signal and the first low frequency band signal of the current frame of the speech or audio signal into a wide frequency band signal.

By using the method and apparatus for switching a speech or audio signal in an embodiment of the invention, the first high frequency band signal of the current frame of the speech or audio signal is converted to the second high frequency band signal of the previous M frame of the speech or audio signal. The second high frequency band signal of the previous M frame of speech or audio signal can be smoothly switched to the processed first high frequency band signal. The processed first high frequency band signal and the first low frequency band signal are synthesized into a wide frequency band signal. In this way, during the switching process between speech or audio signals having different bandwidths, such speech or audio signals can be switched smoothly, thus adversely affecting the energy jump on the subjective audio quality of the speech or audio signal. To improve the quality of the speech or audio signal that the user receives.

BRIEF DESCRIPTION OF THE DRAWINGS In order to clarify the technical solutions of the present invention, an overview of the accompanying drawings is shown below for illustrating an embodiment of the present invention. Apparently, the accompanying drawings are merely illustrative, and a person of ordinary skill in the art may derive other drawings from these accompanying drawings without creative efforts.
1 is a flow diagram of a first implementation of a method for switching speech or audio signals.
2 is a flowchart of a second implementation of a method for switching speech or audio signals.
3 is a flow diagram of an implementation of step 201 shown in FIG.
4 is a first flowchart of an implementation of step 302 shown in FIG.
FIG. 5 is a second flowchart of another implementation of step 302 shown in FIG. 3.
6 is a first flow diagram of an implementation of step 202 shown in FIG. 2.
FIG. 7 is a second flowchart of another implementation of step 201 shown in FIG. 2.
FIG. 8 is a third flow diagram of another implementation of step 201 shown in FIG. 2.
9 is a structural diagram of a first embodiment of an apparatus for switching speech or audio signals.
10 is a structural diagram of a second embodiment of an apparatus for switching speech or audio signals.
11 is a first schematic diagram illustrating the structure of a processing module of a second embodiment of an apparatus for switching speech or audio signals.
12 is a schematic diagram illustrating the structure of a first module of a second embodiment of an apparatus for switching speech or audio signals.
13A is a second schematic diagram illustrating the structure of a processing module of a second embodiment of an apparatus for switching speech or audio signals.
13B is a third schematic diagram illustrating the structure of a processing module of a second embodiment of an apparatus for switching speech or audio signals.

In order to understand the objects, technical solutions and advantages of the present invention, the following description describes the present invention in detail with reference to the embodiments and the accompanying drawings. Apparently, the embodiments are merely exemplary and the present invention is not limited to these embodiments. Those skilled in the art can derive other embodiments from the embodiments described herein without significant creative effort, and all such embodiments are within the scope of the present invention.

1 is a flow diagram of a first implementation of a method for switching speech or audio signals. As shown in FIG. 1, by using a method for switching speech or audio signals, when switching of speech or audio occurs, each of the frames after the switching frame are processed according to the following steps.

Step 101: M is greater than or equal to 1, and when switching of speech or audio occurs, weights the first high frequency band signal of the current frame of the speech or audio signal and the second high frequency band signal of the previous M frame of the speech or audio signal. Weighting to obtain a processed first high frequency band signal.

Step 102: Synthesize the processed first high frequency band signal and the first low frequency band signal of the current frame of the speech or audio signal into a wide frequency band signal.

In this embodiment, the previous M frame of the speech or audio signal refers to the M frame of the speech or audio signal before the current frame. The L frame of the speech or audio signal before switching refers to the L frame of the speech or audio signal before the switching frame when switching of speech or audio occurs. If the current speech frame is a wide frequency band signal and the previous speech frame is a narrow frequency band signal, or if the current speech frame is a narrow frequency band signal and the previous speech frame is a wide frequency band signal, the speech or audio signal is switched. The current speech frame is a switching frame.

By using the method for switching the speech or audio signal of the present embodiment, the first high frequency band signal of the current frame of the speech or audio signal is processed according to the second high frequency band signal of the previous M frame of the speech or audio signal, Alternatively, the second high frequency band signal of the previous M frame of the audio signal may be smoothly switched to the processed first high frequency band signal. In this way, during the switching process between speech or audio signals having different bandwidths, the high frequency band signals of such speech or audio signals can be smoothly switched. As a result, the processed first high frequency band signal and the first low frequency band signal are synthesized into a wide frequency band signal. And the wide frequency band signal is transmitted to the user terminal, so that the user can enjoy a high quality speech or audio signal. By using the method for switching the speech or audio signal of the present embodiment, speech or audio signals having different bandwidths can be smoothly switched, and thus with a sudden energy jump to the subjective audio quality of the speech or audio signal. It reduces the effects of the effects and improves the quality of the speech or audio signal you receive.

2 is a flowchart of a second implementation of a method for switching speech or audio signals. As shown in FIG. 2, the method includes the following steps.

Step 200: If switching of speech or audio does not occur, synthesize the first high frequency band signal and the first low frequency band signal of the current frame of speech or audio signal into the wide frequency band signal.

Specifically, the first frequency band speech or audio signal of the present embodiment may be a wide frequency band speech or audio signal or a narrow frequency band speech or audio signal. If the first frequency band speech or audio signal is not switched while transmitting the speech or audio signal, the operation may be performed in the following two cases. 1. When the first frequency band speech or audio signal is a wide frequency band speech or audio signal, the low frequency band signal and the high frequency band signal of the wide frequency band speech or audio signal are synthesized into a wide frequency band signal. 2. If the first frequency band speech or audio signal is a narrow frequency band speech or audio signal, the low frequency band signal and the high frequency band signal of the narrow frequency band speech or audio signal are synthesized into a wide frequency band signal. In this case, even if the signal is a wide frequency band signal, the high frequency band is null.

Step 201: When the speech or audio signal is switched, the first high frequency band signal of the current frame of the speech or audio signal and the second high frequency band signal of the previous M frame of the speech or audio signal are weighted to process the first high frequency. Acquire a band signal. M is greater than or equal to one.

Specifically, when switching between speech or audio signals having different bandwidths occurs, the first high frequency band signal of the current frame of the speech or audio signal is processed according to the second high frequency band signal of the previous M frame of the speech or audio signal. The second high frequency band signal of the previous M frame of the speech or audio signal can be smoothly switched to the processed first high frequency band signal. For example, when a wide frequency speech or audio signal is switched to a narrow frequency speech or audio signal, the narrow frequency speech or audio signal is high because the high frequency band signal information corresponding to the narrow frequency speech or audio signal is null. The high frequency band signal component corresponding to C needs to be recovered in order to allow a wide frequency band speech or audio signal to be smoothly switched to a narrow frequency band speech or audio signal. However, when narrow frequency band speech or audio signals are switched to wide frequency speech or audio signals, the high frequency band signal information of the wide frequency band speech or audio signals is not null, so that successive multi-frames after switching (cosecutive multi) The energy of a wide frequency band speech or audio signal of an audio signal should be weak in order to allow a narrow frequency band speech or audio signal to be smoothly switched to a wide frequency speech or audio signal. This allows the high frequency band signal of a wide frequency band speech or audio signal to be gradually switched to the actual high frequency band signal. By processing the current frame of the speech or audio signal of step 201, the high frequency band signal of the speech or audio signal having the different bandwidth can be smoothly switched, which is between the wide frequency band speech or audio signal and the narrow frequency band speech or audio signal. This prevents uncomfortable listening of the user due to sudden energy change in the switching process, allowing the user to receive a high quality audio signal. In order to simplify the process of obtaining the processed first high frequency band signal, the first high frequency band signal and the second high frequency band signal of the previous M frame of the speech or audio signal can be directly weighted. The weighted result is the processed first high frequency band signal.

Step 202: Synthesize the processed first high frequency band signal and the first low frequency band signal of the current frame of the speech or audio signal into a wide frequency band signal.

Specifically, after the current frame of the speech or audio signal is processed in step 201, the second high frequency band signal of the previous M frame of the speech or audio signal may be smoothly switched to the processed first high frequency band signal of the current frame. Then, in step 202, the processed first high frequency band signal and the first low frequency band signal of the current frame of the speech or audio signal are synthesized into a wide frequency band signal such that the speech or audio signal received by the user is always in the wide frequency band. Be a speech or audio signal. In this way, speech or audio signals with different bandwidths are smoothly switched, which helps to improve the quality of the audio signal that the user receives.

By using the method for switching the speech or audio signal of the present embodiment, the first high frequency band signal of the current frame of the speech or audio signal is processed according to the second high frequency band signal of the previous M frame of the speech or audio signal, Or allow the second high frequency band signal of the previous M frame of the audio signal to be smoothly switched to the processed first high frequency band signal. In this way, during the switching process between speech or audio signals having different bandwidths, the high frequency band signals of such speech or audio signals can be smoothly switched. As a result, the processed first high frequency band signal and the first low frequency band signal are synthesized into a wide frequency band signal. And the wide frequency band signal is transmitted to the user terminal, so that the user can enjoy a high quality speech or audio signal. By using the method for switching the speech or audio signal of the present embodiment, speech or audio signals having different bandwidths can be smoothly switched, thus reducing the effect of sudden energy jump on the subjective audio quality of the speech or audio signal. And improve the quality of the speech or audio signal that the user receives. In addition, when speech or audio signals having different bandwidths are not switched, the first high frequency band signal and the first low frequency band signal of the current frame of the speech or audio signal are synthesized into a wide frequency band signal, so that the user can obtain high quality audio. Allows you to acquire a signal.

According to the foregoing technical solution, as shown in FIG. 3, when switching from a wide frequency band speech or audio signal to a narrow frequency band speech or audio signal occurs, step 201 optionally includes the following steps.

Step 301: Predict fine structure information and envelope information corresponding to the first high frequency band signal.

Specifically, the speech or audio signal may be divided into fine structure information and envelope information, so that the speech or audio signal may be reconstructed according to the fine structure information and the envelope information. In the process of switching from a wide frequency band speech or audio signal to a narrow frequency band speech or audio signal, because only the low frequency band signal is available in the narrow frequency band speech or audio signal and the high frequency band signal is null, the wide frequency band speech or In order to enable the audio signal to be smoothly switched to narrow frequency band speech or audio signals, the high frequency band signals required by current narrow frequency band speech or audio signals are restored to enable smooth switching between speech or audio signals. Need to be. In step 301, predicted microstructure information and envelope information corresponding to the narrow frequency band speech or the first high frequency band signal of the audio signal are predicted.

In order to more accurately predict the microstructure information and envelope information corresponding to the current frame of the speech or audio signal, in step 301 the first low frequency band signal of the current frame of the speech or audio signal is classified, and then applied to the first high frequency band signal. Corresponding predicted microstructure information and envelope information are predicted according to the signal type of the first low frequency band signal. For example, the narrow frequency band speech or audio signal of the current frame may be a harmonic signal, or a non-harmonic signal or a transient signal. In this case, fine structure information and envelope information corresponding to the narrow frequency band speech or audio signal type can be obtained, so that the fine structure information and envelope information corresponding to the high frequency band signal can be predicted more accurately. The method for switching the speech or audio signal of this embodiment does not limit the signal type of the narrow frequency band speech or audio signal.

Step 302: Weighting the predicted envelope information corresponding to the second high frequency band signal of the previous M frame of the speech or audio signal and the previous M frame envelope information to obtain first envelope information corresponding to the first high frequency band signal.

Specifically, after the predicted microstructure information and envelope information corresponding to the first high frequency band signal of the current frame are predicted in step 301, the first envelope information corresponding to the first high frequency band signal may be predicted envelope information and speech or It may be generated according to the previous M frame envelope information corresponding to the second high frequency band signal of the previous M frame of the audio signal.

In detail, the process of generating first envelope information corresponding to the first high frequency band signal of step 302 may be implemented using the following two modes.

1. As shown in FIG. 4, an implementation of obtaining the first envelope information through step 302 includes the following steps.

Step 401: Correlation coefficient between the first low frequency band signal and the low frequency band signal of the previous N frame of the speech or audio signal, according to the low frequency band signal of the first N frame of the speech or audio signal. , Where N is greater than or equal to 1.

Specifically, the first low frequency band signal of the current frame of the speech or audio signal is compared with the low frequency band signal of the previous N frames of the speech or audio signal to compare the first low frequency band signal and the speech or audio signal of the current frame of the speech or audio signal. Obtain the correlation coefficient between the low frequency band signals of the previous N frames. For example, the first low frequency band signal of the current frame of the speech or audio signal and the low frequency band signal of the previous N frame of the speech or audio signal may be the frequency band and speech of the first low frequency band signal of the current frame of the speech or audio signal. Or by determining the difference in energy magnitude or information type between the frequency bands of the low frequency band signal of the previous N frames of the audio signal, so that the required correlation coefficient can be calculated. The previous N frame of the speech or audio signal may be a narrow frequency band speech or audio signal, a broad frequency band speech or audio signal, or a narrow frequency band speech or audio signal and a hybrid signal of a wide frequency band speech or audio signal.

Step 402: Determine whether the correlation coefficient is within a predetermined first threshold range.

Specifically, after the correlation coefficient is calculated at step 401, it is determined whether the correlation coefficient is within a predetermined first threshold range. The purpose of calculating the correlation coefficient is to determine whether the current frame of the speech or audio signal is switched progressively from the previous N frames of the speech or audio signal or abruptly from the previous N frames of the speech or audio signal. That is, the purpose is to determine whether their features are the same and then to determine the weight of the high frequency band signal of the previous frame in the process of predicting the high frequency band signal of the current speech or audio signal. For example, if the first low frequency band signal of the current frame of the speech or audio signal has the same energy as the low frequency band signal of the previous frame of the speech or audio signal, and their signal types are also the same, the previous frame of the speech or audio signal Indicates that there is a high degree of correlation with the current frame of this speech or audio signal. Thus, to accurately reconstruct the first envelope information corresponding to the current frame of the speech or audio signal, the high frequency band envelope information or the transitional envelope information corresponding to the previous frame of the speech or audio signal has a large weight. Alternatively, if there is a large difference in energy and their signal types between the first low frequency band signal of the current frame of the speech or audio signal and the low frequency band signal of the previous frame of the speech or audio signal, speech or audio Indicates that the previous frame of the signal has low correlation with the current frame of the speech or audio signal. Thus, in order to correctly reconstruct the first envelope information corresponding to the current frame of the speech or audio signal, the high frequency band envelope information or the transition envelope information corresponding to the previous frame of the speech or audio signal has a small weight.

Step 403: If the correlation coefficient is not within the first threshold range, the first envelope information is calculated by weighting according to the set first weight 1 and the set first weight 2. The first weight 1 indicates a weight value of previous frame envelope information corresponding to the high frequency band signal of the previous frame of the speech or audio signal, and the first weight 2 indicates a weight value of the envelope information.

Specifically, if it is determined in step 402 that the correlation coefficient is not within the predetermined first threshold range, it indicates that the current frame of the speech or audio signal is slightly correlated with the previous N frames of the speech or audio signal. Accordingly, the transitional envelope information corresponding to the previous M frame envelope information or the first frequency band speech or audio signal of the previous M frame, or the high frequency band envelope information corresponding to the previous frame of the speech or audio signal is determined according to the first envelope information. Has some effect on When the first envelope information corresponding to the current frame of the speech or audio signal is restored, the transition envelope information, or speech or audio, corresponding to the previous M frame envelope information or the first frequency band speech or audio signal of the previous M frame. The high frequency band envelope information corresponding to the previous frame of the signal has a small weight. Therefore, the first envelope information of the current frame may be calculated according to the set first weight 1 and the first weight 2. The first weight 1 indicates a weight value of envelope information corresponding to the high frequency band signal of the previous frame of the speech or audio signal. The previous frame of speech or audio signal may be a wide frequency band speech or audio signal or a processed narrow frequency band speech or audio signal. For the first switching, the previous frame of the speech or audio signal is a wide frequency band speech or audio signal, while the first weight 2 indicates the weight value of the predicted envelope information. After the product of the predicted envelope information and the first weight 2 is added to the product of the previous frame envelope information and the first weight 1, the weighted sum is the first envelope information of the current frame. In addition, sequentially transmitted speech or audio signals are processed according to this method and weighting. The first envelope information corresponding to the speech or audio signal is recovered until the speech or audio signal is switched again.

Step 404: If the correlation coefficient is within a predetermined first threshold range, calculate envelope information weighted and transitioned according to the set second weight 1 and the set second weight 2. The second weight 1 indicates a weight value of the envelope information before the switching, the second weight 2 indicates a weight value of the previous M frame envelope information, and M is greater than or equal to one.

Specifically, if it is determined in step 402 that the correlation coefficient is within a predetermined threshold range, the current frame of the speech or audio signal has characteristics similar to that of a previous consecutive N frame of speech or audio signal, The first envelope information corresponding to the current frame of the signal is greatly affected by the envelope information of previous consecutive N frames of the speech or audio signal. In terms of authenticity of the previous M frame envelope, the transitional envelope information corresponding to the current frame of the speech or audio signal needs to be calculated according to the previous M frame envelope information and the envelope information before switching. When the first envelope information of the current frame of the speech or audio signal is restored, the previous M frame envelope information and the previous L frame envelope information before switching should have a large weight. After that, the first envelope information is calculated according to the transitional envelope information. The second weight 1 indicates a weight value of the envelope information before switching, and the second weight 2 indicates a weight value of the previous M frame envelope information. In this case, the product of the envelope information before switching and the second weight 1 is added to the product of the previous M frame envelope information and the second weight 2, and the weighted value is the transitional envelope information.

Step 405: Decrease the second weight 1 according to the first weighting step and increase the second weight 2 according to the first weighting step.

Specifically, as the speech or audio signal is transmitted, the influence of the wide frequency band speech or audio signal prior to switching on the sequential narrow frequency band speech or audio signal is gradually reduced. In order to calculate the first envelope information more accurately, adaptive adjustment needs to be performed for the second weight 1 and the second weight 2. Since the influence of the wide frequency band speech or audio signal of the L frame before switching on the sequential speech or audio signal is gradually reduced, the value of the second weight 1 gradually decreases while the value of the second weight 2 gradually. It becomes larger, thereby weakening the influence of the envelope information before switching on the first envelope information. In step 405, the second weight 1 and the second weight 2 are obtained by the following equations: new second weight 1 = existing second weight 1-first weighting; The new second weight 2 = can be modified according to the existing second weight 2 + first weighting step, where the first weighting step is a set value.

Step 406: Determine whether the set third weight 1 is greater than the first weight 1.

Specifically, the third weight 1 indicates the weight value of the envelope information to be transitioned. The influence of the transitioning envelope information on the first envelope information of the current frame may be determined by comparing the third weight 1 with the second weight 1. Transitioning envelope information is calculated according to the previous M frame envelope information and the envelope information before switching. Thus, the third weight 1 actually represents the degree of influence that the first envelope information suffers from the envelope information before switching.

Step 407: If the third weight 1 is not greater than the first weight 1, calculate the first envelope information by weighting according to the set first weight 1 and the first weight 2.

Specifically, when the third weight 1 is determined to be less than or equal to the first weight 1 in step 406, the current frame of the speech or audio signal is slightly further from the L frame of the speech or audio signal before switching and the first. Envelope information mainly indicates that it is affected by the previous M frame envelope information. Therefore, the first envelope information of the current frame may be calculated according to the set first weight 1 and the first weight 2.

Step 408: If the third weight 1 is greater than the first weight 1, calculate the first envelope information by weighting according to the set third weight 1 and the third weight 2. The third weight 1 indicates a weight value of the transitional envelope information, and the third weight 2 indicates a weight value of the predicted envelope information.

Specifically, if it is determined that the third weight 1 is greater than the first weight 1 in step 406, the current frame of the speech or audio signal is close to the L frame of the speech or audio signal before switching and the first envelope information is nearly switched. Indicates that it is affected by previous envelope information. Therefore, the first envelope information of the current frame needs to be calculated according to the transitional envelope information. The third weight 1 indicates a weight value of the transitional envelope information, and the third weight 2 indicates a weight value of the predicted envelope information. In this case, the product of the transitional envelope information and the third weight 1 is added to the product of the predicted envelope information and the third weight 2, but the weighted value is the first envelope information.

Step 409: Decrease the third weight 1 according to the second weighting step and increase the third weight 2 according to the second weighting step until the third weight 1 becomes zero.

In detail, the purpose of modifying the third weight 1 and the third weight 2 in step 409 is the same as the purpose of modifying the second weight 1 and the second weight 2 in step 405. That is, the purpose of performing the adaptive adjustment for the third weight 1 and the third weight 2 is when the influence of the L frame of the speech or audio signal before switching on the sequentially transmitted speech or audio signal is gradually reduced. To calculate the first envelope information more accurately. Since the influence of the L frame of the speech or audio signal before switching on the sequential speech or audio signal is gradually reduced, the value of the third weight 1 gradually decreases while the value of the third weight 2 gradually increases, Accordingly, the influence of the envelope information before switching on the first envelope information is weakened. In step 409, the third weight 1 and the third weight 2 are obtained by the following equations: new third weight 1 = existing third weight 1-second weighting; The new third weight 2 = can be modified according to the existing third weight 2 + second weighting step, where the second weighting step is a set value.

The sum of the first weight 1 and the first weight 2 is 1, the sum of the second weight 1 and the second weight 2 is 1, the sum of the third weight 1 and the third weight 2 is 1, the third weight of 1 The initial value is greater than the initial value of the first weight 1; The first weight 1 and the first weight 2 are fixed constants. Specifically, the weights 1 and 2 of the present embodiment actually indicate the percentage of previous M frame envelope information and envelope information before switching in the first envelope information of the current frame. If the current frame of the speech or audio signal is close to the L frame of the speech or audio signal before switching and their correlation is high, the percentage of envelope information before switching is high but the percentage of previous M frame envelope information is low. If the current frame of the speech or audio signal is slightly away from the L frame of the speech or audio signal before switching, it indicates that the speech or audio signal is transmitted stably over the network, or if the current frame of the speech or audio signal is If slightly correlated with the L frame of the speech or audio signal prior to this switching, it indicates that the characteristics of the current frame of the speech or audio signal have already changed. Thus, if the current frame of speech or audio signal is slightly affected by the L frame of speech or audio signal before switching, the percentage of envelope information before switching is low.

In addition, step 404 may be executed after step 405. That is, the second weight 1 and the second weight 2 may be modified first, and then the envelope information to transition is calculated according to the second weight 1 and the second weight 2. Similarly, step 408 may be executed after step 409. That is, the third weight 1 and the third weight 2 may be modified first, and then the first envelope information is calculated according to the third weight 1 and the third weight 2.

2. As shown in FIG. 5, another implementation of obtaining the first envelope information through step 302 may further include the following steps.

Step 501: Between the first low frequency band signal of the current frame of the speech or audio signal and the low frequency band signal of the previous frame of the speech or audio signal, between the first low frequency band signal and the low frequency band signal of the previous frame of the speech or audio signal. Calculate the correlation coefficient.

Specifically, in order to obtain more accurate first envelope information, there is a relationship between the frequency band of the first low frequency band signal of the current frame of the speech or audio signal and the same frequency band of the low frequency band signal of the previous frame of the speech or audio signal. Is calculated. In this embodiment, "corr" may be used to indicate a correlation coefficient. This correlation coefficient may be obtained according to an energy relationship between the frequency band of the first low frequency band signal of the current frame of the speech or audio signal and the low frequency band signal of the previous frame of the speech or audio signal. If the energy difference is small, the "corr" is large; In the opposite case, "corr" is small. For a specific process, see the calculation regarding correlation of previous N frames of speech or audio signal in step 401.

Step 502: Determine whether the correlation coefficient is within a predetermined second threshold range.

Specifically, after the value of "corr" is calculated in step 501, it is determined whether the calculated "corr" value is within a predetermined second threshold. For example, the second threshold range may be labeled c1 to c2 in this embodiment.

Step 503: If the correlation coefficient is not within the predetermined second threshold range, the first envelope information is calculated by weighting according to the set first weight 1 and the set first weight 2. The first weight 1 indicates a weight value of previous frame envelope information corresponding to the high frequency band signal of the previous frame of the speech or audio signal, and the first weight 2 indicates a weight value of the predicted envelope information. The first weight 1 and the first weight 2 are fixed constants.

Specifically, when it is determined that the value of "corr" is less than c1 or greater than c2, the first envelope information corresponding to the current frame of the speech or audio signal is slightly changed by the envelope information of the previous frame of the speech or audio signal before switching. It was decided to be affected. Therefore, the first envelope information of the current frame is calculated according to the set first weight 1 and the first weight 2. The product of the predicted envelope information and the first weight 2 is added to the product of the previous frame envelope information and the first weight 1, and the weighted sum is the first envelope information of the current frame. Furthermore, narrow band speech or audio signals transmitted sequentially are processed according to the present method and weights. The first envelope information corresponding to the narrow band speech or audio signal is recovered until the speech or audio signal having a different bandwidth is switched again. For example, the first weight 1 of the present embodiment may be represented by a1, the first weight 2 may be represented by b1, the previous frame envelope information may be represented by pre_fenv, and the predicted envelope information is fenv. The first envelope information may be expressed as cur_fenv. In this case, step 503 may be represented by the following equation, cur_fenv = pre_fenv x a1 + fenv x b1.

Step 504: If the correlation coefficient is within a second threshold range, determine whether the set second weight 1 is greater than the first weight 1. The second weight 1 indicates the weight value of the envelope information before switching corresponding to the high frequency band signal of the previous frame of the speech or audio signal before switching.

Specifically, if c1 <corr <c2, the degree of influence of the previous frame envelope information on the envelope information before switching and the first envelope information of the current frame may be obtained by comparing the second weight 1 with the first weight 1. have.

Step 505: If the second weight 1 is not greater than the first weight 1, calculate the first envelope information by weighting the set first weight 1 according to the first weight 2.

Specifically, when it is determined that the second weight 1 is less than the first weight 1 in step 504, it means that the current frame of the speech or audio signal is slightly far from the previous frame of the speech or audio signal before switching and the first envelope information is switched. Indicates that it is slightly affected by the previous previous frame envelope information. Therefore, the first envelope information of the current frame may be calculated according to the set first weight 1 and the first weight 2. In this case, step 505 may be represented by the following equation, cur_fenv = pre_fenv x a1 + fenv x b1.

Step 506: If the second weight 1 is greater than the first weight 1, weight the first weight information according to the second weight 1 and the set second weight 2 to calculate the first envelope information. The second weight 2 indicates a weight value of the predicted envelope information. For example, the second weight 1 may be represented by a2 and the second weight 2 may be represented by b2.

Specifically, when it is determined that the second weight 1 is greater than the first weight 1 in step 504, it is determined that the current frame of the speech or audio signal is close to the first frequency band speech or audio signal of the previous frame before switching and the first envelope. The information indicates that the pre-switching speech or the pre-switching envelope information corresponding to the previous frame of the audio signal is greatly affected. Therefore, the first envelope information of the current frame may be calculated according to the set second weight 1 and the second weight 2. In this case, the product of the predicted envelope information and the second weight 2 is added to the product of the envelope information and the second weight 1 before switching, and the weighted sum is the first envelope information of the current frame. Envelope information before switching may be represented by con_fenv. In this case, step 506 may be represented by the following equation, cur_fenv = pre_fenv x a2 + fenv x b2.

Step 507: Decrease the second weight 1 according to the second weighting step and increase the second weight 2 according to the second weighting step.

Specifically, as the speech or audio signal is transmitted, the effect of the speech or audio signal prior to switching on sequential frames of the speech or audio signal is gradually reduced. In order to calculate the first envelope information more accurately, adaptive adjustment needs to be performed for the second weight 1 and the second weight 2. The effect of the speech or audio signal prior to switching on the sequential frames of speech or audio signal is gradually reduced, but the influence of the previous frame of the speech or audio signal close to the current frame of the speech or audio signal is gradually increased. Therefore, the value of the second weight 1 gradually decreases while the value of the second weight 2 gradually increases. In this way, the influence of the envelope information before switching on the first envelope information is weakened, but the influence of the predicted envelope information on the first envelope information is enhanced. In step 507, the second weight 1 and the second weight 2 are the following equations: new second weight 1 = existing second weight 1-first weighting step; The new second weight 2 = can be modified according to the existing second weight 2 + first weighting step, where the first weighting step is a set value.

The sum of the first weight 1 and the first weight 2 is 1, the sum of the second weight 1 and the second weight 2 is 1, and the initial value of the second weight 1 is greater than the initial value of the first weight 1.

Step 303: Generate a processed high frequency band signal according to the first envelope information and the predicted microstructure information.

Specifically, after the first envelope information of the current frame is obtained in step 302, the processed first high frequency band signal may be generated according to the first envelope information and the predicted microstructure information, so that the second high frequency band signal is processed Can be switched smoothly to the first high frequency band signal.

In the process of switching a speech or audio signal from a wide frequency band speech or audio signal to a narrow frequency band speech or audio signal by using the method for switching the speech or audio signal of the present embodiment, the processed first high frequency of the current frame The band signal is obtained according to the predicted microstructure information and the first envelope information. In this way, the second high frequency band signal of the wide frequency band speech or audio signal before switching can be smoothly switched to the processed first high frequency band signal corresponding to the narrow frequency band speech or audio signal. Improve the quality of the audio signal you receive.

Based on the foregoing technical solution, step 202 shown in FIG. 6 includes the following steps.

Step 601: Determine whether the processed first high frequency band signal needs to be attenuated according to the current frame of the speech or audio signal and the previous frame of the speech or audio signal before switching.

Specifically, the first high frequency band signal of the narrow band speech or audio signal is null. In the process of switching from a wide frequency band speech or audio signal to a narrow frequency band speech or audio signal, to prevent the negative effects of the processed first high frequency band signal corresponding to the restored narrow frequency band speech or audio signal. The energy of the first high frequency band signal is framed until the attenuation coefficient reaches a predetermined threshold after the number of frames of the wide frequency band signal extended from the narrow frequency band speech or audio signal reaches a predetermined number of frames. Attenuated by. The interval between the speech or audio signal of the current frame of the speech or audio signal and the frame before switching may be obtained according to the speech or audio signal of the current frame of the speech or audio signal and the frame before switching. For example, the number of narrow frequency band speech or frames of an audio signal may be recorded using a counter, where the number of frames may be a predetermined value greater than or equal to zero.

Step 602: If the processed first high frequency band signal does not need to be attenuated, synthesize the processed first high frequency band signal and the first low frequency band signal into a wide frequency band signal.

Specifically, if it is determined that the processed first high frequency band signal does not need to be attenuated in step 601, the processed first high frequency band signal and the first low frequency band signal are directly synthesized into a wide frequency band signal.

Step 603: If the processed first high frequency band signal needs attenuation, determine whether the attenuation factor corresponding to the processed first high frequency band signal is greater than a threshold.

Specifically, the initial value of the attenuation factor is 1 and the threshold is greater than or equal to 0 and less than 1. If the processed first high frequency band signal needs to be attenuated in step 601, it is determined in step 603 whether the attenuation factor corresponding to the processed first high frequency band signal is greater than a predetermined threshold.

Step 604: If the attenuation factor is not greater than a predetermined threshold, multiply the processed first high frequency band signal by a threshold and synthesize this product and the first low frequency band signal into a wide frequency band signal.

Specifically, if it is determined that the attenuation factor is not greater than the predetermined threshold in step 603, it means that the energy of the processed first high frequency band signal has already been attenuated to some extent and that the processed first high frequency band signal will not cause a negative effect. To indicate that it can. In this case, this attenuation ratio can be maintained. Thereafter, after the processed first high frequency band signal is multiplied by a threshold, the product of the first low frequency band signal is synthesized into a wide frequency band signal.

Step 605: If the attenuation factor is greater than the predetermined threshold, multiply the processed first high frequency band signal by the attenuation factor and synthesize this product and the first low frequency band signal into a wide frequency band signal.

Specifically, if the attenuation factor is greater than the predetermined threshold in step 603, it may cause the processed first high frequency band signal to cause poor listening in the attenuation factor, which reaches a predetermined threshold. Indicates that it needs to be attenuated further before. Then, after the processed first high frequency band signal is multiplied by the attenuation factor, this product and the first low frequency band signal are synthesized into a wide frequency band signal.

Step 606: Modify the damping factor to reduce the damping factor.

Specifically, as the speech or audio signal is transmitted, the influence of the speech or audio signal prior to switching on the sequential narrow band speech or audio signal gradually decreases, and the attenuation factor also gradually decreases.

Optionally, based on the foregoing technical solution, when switching from a narrow frequency band speech or audio signal to a wide frequency band speech or audio signal occurs, an embodiment of obtaining a processed high frequency band signal through step 201 may include , As shown in FIG. 7.

Step 701: Calculate the processed first high frequency band signal by weighting according to the set fourth weight 1 and the fourth weight 2. The fourth weight 1 indicates a weight value of the second high frequency band signal, and the fourth weight 2 indicates a weight value of the first high frequency band signal of the current frame of the speech or audio signal.

Specifically, in the switching process from narrow frequency band speech or audio signal to wide frequency speech or audio signal, the high frequency band signal of the wide frequency band speech or audio signal is not null and the high frequency corresponding to the narrow frequency band speech or audio signal. Since the band signal is null, the energy of the high frequency band signal of the wide frequency band speech or audio signal needs to be attenuated to ensure that the narrow frequency band speech or audio signal can be smoothly switched to the wide frequency band speech or audio signal. have. The product of the second high frequency band signal and the fourth weight 1 is added to the product of the first high frequency band signal and the fourth weight 2 and the weighted value is the processed first high frequency band signal.

Step 702: Decrease the fourth weight 1 according to the third weighting step and increase the fourth weight 2 according to the third weighting step until the fourth weight 1 becomes zero. The sum of the fourth weight 1 and the fourth weight 2 is one.

Specifically, as the speech or audio signal is transmitted, the influence of the narrow frequency band speech or audio signal prior to switching on the sequential wide frequency band speech or audio signal becomes progressively smaller. Accordingly, the fourth weight 1 gradually decreases while the fourth weight 2 gradually increases until the fourth weight 1 becomes 0 and the fourth weight 2 becomes 1. That is, the transmitted speech or audio signal is always a wide frequency band speech or audio signal.

Similarly, as shown in FIG. 8, another implementation of obtaining the first high frequency band signal processed through step 201 may further include the following steps.

Step 801: Compute the weighted processed high frequency band signal according to the set fifth weight 1 and the set fifth weight 2. The fifth weight 1 is a fixed parameter, and the fifth weight 2 is a weight value of the first high frequency band signal of the current frame of the speech or audio signal.

Specifically, since the first high frequency band signal of the narrow frequency band speech or audio signal is null, the fixed parameter may be set to replace the high frequency band signal of the narrow frequency band speech or audio signal, where the fixed parameter is greater than zero. Is equal to and less than the energy of the first high frequency band signal. The product of the fixed parameter and the fifth weight 1 is added to the product of the first high frequency band signal and the fifth weight 2, and the weighted value is the processed first high frequency band signal.

Step 802: Decrease the fifth weight 1 according to the fourth weighting step and increase the fifth weight 2 according to the fourth weighting step until the fifth weight 1 becomes zero. The sum of the fifth weight 1 and the fifth weight 2 is equal to one.

Specifically, as the speech or audio signal is transmitted, the influence of the narrow frequency band speech or audio signal prior to switching on the sequential wide frequency band speech or audio signal becomes progressively smaller. Accordingly, the fifth weight 1 gradually decreases while the fifth weight 2 gradually increases until the fifth weight 1 becomes 0 and the fifth weight 2 becomes 1. In other words, the transmitted speech or audio signal is always actually a wide frequency band speech or audio signal.

By using the method for switching the speech or audio signal of the present embodiment, in the process of switching the speech or audio signal from the narrow frequency band speech or audio signal to the wide frequency band speech or audio signal, the wide frequency band speech or audio signal The high frequency band signal is attenuated to obtain a processed high frequency band signal. In this way, the high frequency band signal of the narrow frequency band speech or audio signal before switching can be smoothly switched to the processed high frequency band signal corresponding to the wide frequency band speech or audio signal, thus the user receives the audio signal. Helps to improve the quality of

In this implementation, the envelope information may also be replaced with other parameters representing a high frequency band signal, such as a linear predictive coding (LPC) parameter or an amplitude parameter.

Those skilled in the art can understand that all steps or some steps of the method according to the embodiment of the present invention can be implemented by a program instructing related hardware. The program may be stored in a computer readable storage medium. When the program is executed, the steps of the method according to the embodiment of the present invention are performed. The storage medium may be read only memory (ROM), random access memory (RAM), magnetic disk or compact disk-read only memory (CD-ROM).

9 is a structural diagram of a first embodiment of an apparatus for switching speech or audio signals. As shown in FIG. 9, an apparatus for switching speech or audio signals includes a processing module 91 and a first synthesis module 92.

When switching of speech or audio occurs, the processing module 91 weights the first high frequency band signal of the current frame of the speech or audio signal and the second high frequency band signal of the previous M frame of the speech or audio signal, thereby processing And to obtain a first high frequency band signal. M is greater than or equal to one.

The first synthesis module 92 is configured to synthesize the processed first high frequency band signal and the first low frequency band signal of the current frame of the speech or audio signal into a wide frequency band signal.

In the apparatus for switching the speech or audio signal of the present embodiment, the processing module processes the first high frequency band signal of the current frame of the speech or audio signal according to the second high frequency band signal of the previous M frame of the speech or audio signal, The second high frequency band signal may be smoothly switched to the processed first high frequency band signal. In this way, during the switching process between speech or audio signals having different bandwidths, the high frequency band signals of such speech or audio signals can be smoothly switched. As a result, the first synthesis module synthesizes the processed first high frequency band signal and the first low frequency band signal into a wide frequency band signal. And the wide frequency band signal is transmitted to the user terminal, so that the user can enjoy a high quality speech or audio signal. By using the method for switching the speech or audio signal of the present embodiment, speech or audio signals having different bandwidths can be smoothly switched, thus reducing the effects of sudden energy changes on the subjective audio quality of the speech or audio signal. And improve the quality of the speech or audio signal that the user receives.

10 is a structural diagram of a second embodiment of an apparatus for switching speech or audio signals. As shown in FIG. 10, the apparatus for switching speech or audio signals in this embodiment is based on the first embodiment and further includes a second synthesis module 103.

The second synthesis module 103 is configured to synthesize the first high frequency band signal and the first low frequency band signal into a wide frequency band signal when no speech or audio switching occurs.

In the apparatus for switching the speech or audio signal of the present embodiment, the second synthesizing module uses the first frequency band speech of the current frame or the first high frequency band signal of the audio signal when switching of speech or audio having a different bandwidth does not occur. And synthesize the first low frequency band signal into a wide frequency band signal. In this way, the quality of the speech or audio signal that the user receives is improved.

According to the above technical solution, when switching from a wide frequency band speech or audio signal to a narrow frequency band speech or audio signal occurs, as shown in FIGS. 10 and 11, the processing module 101 may include a first high frequency band. A prediction module 1011 configured to predict fine structure information and envelope information corresponding to the signal; A first generation configured to weight the predicted envelope information corresponding to the second high frequency band signal of the previous M frame of the speech or audio signal and the previous M frame envelope information to obtain first envelope information corresponding to the first high frequency band signal Module 1012; And a second generation module 1013 configured to generate a first high frequency band signal processed according to the first envelope information and the predicted microstructure information.

In addition, the apparatus for switching the speech or audio signal of the present embodiment may include a classification module 1010 configured to classify the first low frequency band signal of the current frame of the speech or audio signal. The prediction module 1011 is further configured to predict the envelope information and the fine structure information corresponding to the first low frequency band signal of the current frame of the speech or audio signal.

In the apparatus for switching the speech or audio signal of the present embodiment, the prediction module predicts the fine structure information and the envelope information corresponding to the first high frequency band signal, so that the processed first high frequency band signal is a first generation module and a second. It can be generated correctly by the generating module. In this way, the first high frequency band signal can be smoothly switched to the processed first high frequency band signal, thereby improving the quality of the speech or audio signal that the user receives. In addition, the classification module classifies the first low frequency band signal of the current frame of the speech or audio signal, and the prediction module obtains the predicted microstructure information and the predicted envelope information according to the signal type. In this way, the predicted microstructure information and the predicted envelope information are more accurate, thereby improving the quality of the speech or audio signal that the user receives.

Based on the foregoing technical solution, the first synthesis module 102 optionally processes according to the current frame of the speech or audio signal and the previous frame of the speech or audio signal before switching, as shown in FIGS. 10 and 12. A first judging module 1021, configured to determine whether the first high frequency band signal needs to be attenuated; A third synthesis module configured to synthesize the processed first high frequency band signal and the first low frequency band signal into a wide frequency band signal when the first determination module 1021 determines that the processed first high frequency band signal does not need to be attenuated (1022); And when the first judging module 1021 determines that the processed first high frequency band signal needs to be attenuated, it is configured to determine whether an attenuation factor corresponding to the processed first high frequency band signal is greater than a predetermined threshold. 2 decision module 1023; If the second judging module 1023 determines that the attenuation factor is not greater than a predetermined threshold, multiply the processed first high frequency band signal by a threshold and combine the product and the first low frequency band signal into a wide frequency band signal. Configured fourth synthesis module 1024; If the second judging module 1023 determines that the attenuation factor is greater than a predetermined threshold, it is configured to multiply the processed first high frequency band signal by the attenuation factor and synthesize the product and the first low frequency band signal into a wide frequency band signal. A fifth synthesizing module 1025; And a first modification module 1026 configured to modify the damping factor to reduce the damping factor.

The initial value of the attenuation factor is 1 and the threshold is greater than or equal to 0 and less than 1.

By using a device for switching speech or audio signals, the processed first high frequency band signal is attenuated, so that the wide frequency band signal obtained by processing the current frame of the speech or audio signal is more accurate and thus received by the user. Can improve the quality of the audio signal.

According to the above technical solution, when switching from a narrow frequency band speech or audio signal to a wide frequency band speech or audio signal occurs, as shown in FIGS. 10 and 13A, the processing module 101 of the present embodiment is configured to be configured. A first calculation module 1011a, configured to calculate a first high frequency band signal that has been weighted and processed according to the fourth weight 1 and the set fourth weight 2; And a second modification module 1012a, configured to decrease the fourth weight 1 according to the third weight step and increase the fourth weight 2 according to the third weight step until the fourth weight 1 becomes zero. , The fourth weight 1 indicates the weight value of the second high frequency band signal, the fourth weight 2 indicates the weight value of the first high frequency band signal, and the sum of the fourth weight 1 and the fourth weight 2 becomes 1.

Similarly, when switching from a narrow frequency band speech or audio signal to a wide frequency band speech or audio signal occurs, as shown in FIGS. 10 and 13B, the processing module 101 of the present embodiment may execute the set fifth weighting factor. A second calculation module 1011b, configured to calculate a first high frequency band signal weighted and processed according to 1 and the set fifth weight 2; And a third modification module 1012b, configured to decrease the fifth weight 1 according to the fourth weighting step and increase the fifth weight 2 according to the fourth weighting step until the fifth weight 1 becomes zero. The fifth weight 1 indicates a fixed parameter, the fifth weight 2 indicates a weight value of the first high frequency band signal, and the sum of the fifth weight 1 and the fifth weight 2 becomes 1. The fixed parameter is a constant greater than or equal to 0 and less than the energy value of the first high frequency band signal.

By using the method for switching the speech or audio signal of the present embodiment, in the process of switching the speech or audio signal from the narrow frequency band speech or audio signal to the wide frequency band speech or audio signal, the wide frequency band speech or audio signal The high frequency band signal is attenuated to obtain a processed high frequency band signal. In this way, the high frequency band signal of the narrow frequency band speech or audio signal before switching can be smoothly switched to the processed high frequency band signal corresponding to the wide frequency band speech or audio signal, thus the user receives the audio signal. Helps to improve the quality of

It should be noted that the above embodiments are only provided to explain the technical solution of the present invention, and are not intended to limit the present invention. While the invention has been described in detail with reference to the above-described embodiments, it will be apparent to those skilled in the art that various modifications and changes can be made without departing from the spirit and scope of the invention. The invention includes them as long as variations and modifications fall within the scope of protection defined by the following claims or their equivalents.

91: processing module 92: first synthesis module
101: processing module 102: first synthesis module
103: second synthesis module
1010 classification module 1011 prediction module
1011a: first calculation module 1011b: second calculation module
1012a: second modification module 1012b: third modification module
1012: first generation module 1013: second generation module
1021: first judgment module 1022: third synthesis module
1023: second determination module 1024: fourth synthesis module
1025: fifth synthesis module 1026: first modification module

Claims (16)

In the switching method for switching speech or audio signals,
M is greater than or equal to 1, and when switching of speech or audio occurs, weighting the first high frequency band signal of the current frame of the speech or audio signal and the second high frequency band signal of the previous M frame of the speech or audio signal ) Obtaining a processed first high frequency band signal; And
Synthesizing the processed first high frequency band signal and a first low frequency band signal of a current frame of a speech or audio signal into a wide frequency band signal
Containing
Switching method. The method of claim 1,
Synthesizing the first high frequency band signal and the first low frequency band signal into the wide frequency band signal when speech or audio switching does not occur
Further comprising
Switching method. The method according to claim 1 or 2,
When switching from a wide frequency band speech or audio signal to a narrow frequency band speech or audio signal occurs, the first high frequency band signal of the current frame of the speech or audio signal and the second high frequency band of the previous M frame of speech or audio signal Weighting the signal to obtain a processed first high frequency band signal,
Predicting fine structure information and envelope information corresponding to a first high frequency band signal of a current frame of the speech or audio signal;
Acquiring first envelope information corresponding to the first high frequency band signal by weighting the predicted envelope information and previous M frame envelope information corresponding to a second high frequency band signal of a previous M frame of the speech or audio signal; ; And
Generating the processed first high frequency band signal according to the first envelope information and the predicted microstructure information
Including,
Switching method. The method of claim 3,
Predicting the fine structure information and envelope information corresponding to the first high frequency band signal of the current frame of the speech or audio signal,
Classifying a first low frequency band signal of a current frame of the speech or audio signal; And
Predicting the microstructure information and envelope information according to the signal type of the first low frequency band signal
Including,
Switching method. The method of claim 3,
Acquiring first envelope information corresponding to the first high frequency band signal by weighting the predicted envelope information and previous M frame envelope information corresponding to a second high frequency band signal of a previous M frame of the speech or audio signal; Is,
N is greater than or equal to 1 and between the first low frequency band signal and the low frequency band signal of the previous N frame of speech or audio signal, depending on the low frequency band signal of the previous N frame of speech or audio signal. Calculating a correlation coefficient of;
Determining whether the correlation coefficient is within a predetermined first threshold range;
Calculating the first envelope information by weighting the correlation coefficient according to the set first weight 1 and the set first weight 2 when the correlation coefficient is not within the first threshold range;
Calculating envelope information that is weighted and transitioned according to the set second weight 1 and the set second weight 2 when the correlation coefficient is within the first threshold range;
Decreasing the second weight 1 according to a first weighting step and increasing the second weight 2 according to the first weighting step;
Determining whether the set third weight 1 is greater than the first weight 1;
If the third weight 1 is not greater than the first weight 1, calculating the first envelope information by weighting the first weight 1 and the first weight 2 according to the set weights 1 and 2;
Calculating the first envelope information by weighting the third weight 1 according to the set third weight 1 and third weight 2 when the third weight 1 is greater than the first weight 1; And
Decreasing the third weight 1 according to a second weighting step and increasing the third weight 2 according to the second weighting step until the third weight 1 becomes zero.
Including,
The first weight 1 indicates a weight value of previous frame envelope information corresponding to a high frequency band signal of a previous frame of a speech or audio signal, the first weight 2 indicates a weight value of the envelope information,
The second weight 1 indicates a weight value of envelope information corresponding to the high frequency band signal of the L frame of the speech or audio signal before switching, and the second weight 2 indicates a weight value of the previous M frame envelope information. L is greater than or equal to 1
The third weight 1 indicates a weight value of the transitioning envelope information, the third weight 2 indicates a weight value of the predicted envelope information,
The sum of the first weight 1 and the first weight 2 is 1, the sum of the second weight 1 and the second weight 2 is 1, the sum of the third weight 1 and the third weight 2 is 1 and The initial value of the third weight 1 is greater than the initial value of the first weight 1; Wherein the first weight 1 and the first weight 2 are fixed constants,
Switching method. The method of claim 3,
Acquiring first envelope information corresponding to the first high frequency band signal by weighting the predicted envelope information and previous M frame envelope information corresponding to a second high frequency band signal of a previous M frame of the speech or audio signal; Is,
A correlation coefficient between the first low frequency band signal of the current frame and the low frequency band signal of the previous frame of the speech or audio signal according to the low frequency band signal of the previous frame of the speech or audio signal Calculating;
Determining whether the correlation coefficient is within a predetermined second threshold range;
Calculating the first envelope information by weighting the correlation coefficient according to the set first weight 1 and the set first weight 2 when the correlation coefficient is not within the second threshold value range;
Determining whether the set second weight 1 is greater than the first weight 1 when the correlation coefficient is within the second threshold range;
Calculating the first envelope information by weighting the second weight 1 based on the set first weight 1 and the first weight 2 when the second weight 1 is not greater than the first weight 1;
Calculating the first envelope information by weighting the second weight 1 based on the second weight 1 and the set second weight 2 when the second weight 1 is greater than the first weight 1; And
Decreasing the second weight 1 according to a second weighting step and increasing the second weight 2 according to the second weighting step.
Including,
The first weight 1 indicates a weight value of previous frame envelope information corresponding to the high frequency band signal of the previous frame of the speech or audio signal, the first weight 2 indicates a weight value of the predicted envelope information, and the first weight. Weight 1 and the first weight 2 are fixed constants,
The second weight 1 indicates a weight value of envelope information corresponding to the high frequency band signal of the previous frame of the speech or audio signal before switching,
The second weight 2 indicates a weight value of the predicted envelope information.
The sum of the first weight 1 and the first weight 2 is 1, the sum of the second weight 1 and the second weight 2 is 1, and the initial value of the second weight 1 is the initial value of the first weight 1. Greater than value,
Switching method. The method of claim 3,
Synthesizing the processed first high frequency band signal and the first low frequency band signal of the current frame of the speech or audio signal into a wide frequency band signal,
Determining whether the processed first high frequency band signal needs to be attenuated in accordance with a current frame of speech or audio signal and a previous frame of speech or audio signal before switching;
If attenuation is not needed, combining the processed first high frequency band signal and the first low frequency band signal into the wide frequency band signal;
If attenuation is necessary, determining whether an attenuation factor corresponding to the first high frequency band signal is greater than a predetermined threshold value;
If the attenuation factor is not greater than the predetermined threshold, multiply the processed first high frequency band signal by the threshold, multiply the processed first high frequency band signal by the threshold and the first low frequency band signal Synthesizing into the wide frequency band signal;
If the attenuation factor is greater than the predetermined threshold, multiply the processed first high frequency band signal by the attenuation factor, multiply the processed first high frequency band signal by the attenuation factor and the first low frequency band signal. Synthesizing into the wide frequency band signal; And
Modifying the damping factor to reduce the damping factor
Including,
The initial value of the attenuation factor is 1, the threshold is greater than or equal to 0 and less than 1,
Switching method. The method according to claim 1 or 2,
When switching from a narrow frequency band speech or audio signal to a wide frequency band speech or audio signal occurs, the first high frequency band signal of the current frame of the speech or audio signal and the second high frequency band of the previous M frame of speech or audio signal Weighting the signal to obtain a processed first high frequency band signal,
Calculating the processed first high frequency band signal by weighting according to the set fourth weight 1 and the set fourth weight 2; And
Decreasing the fourth weight 1 according to a third weighting step and increasing the fourth weight 2 according to the third weighting step until the fourth weight 1 becomes zero.
Including,
The fourth weight 1 indicates a weight value of the second high frequency band signal, and the fourth weight 2 indicates a weight value of the first high frequency band signal,
The sum of the fourth weight 1 and the fourth weight 2 is 1,
Switching method. The method according to claim 1 or 2,
When switching from a wide frequency band speech or audio signal to a narrow frequency band speech or audio signal occurs, the first high frequency band signal of the current frame of the speech or audio signal and the second high frequency band of the previous M frame of speech or audio signal Weighting the signal to obtain a processed first high frequency band signal,
Calculating the processed first high frequency band signal by weighting according to the set fifth weight 1 and the set fifth weight 2; And
Decreasing the fifth weight 1 according to a fourth weighting step and increasing the fifth weight 2 according to the fourth weighting step until the fifth weight 1 becomes zero.
Including,
The fifth weight 1 indicates a fixed parameter, the fifth weight 2 indicates a weight value of the first high frequency band signal,
The sum of the fifth weight 1 and the fifth weight 2 is 1,
The fixed parameter is a constant greater than or equal to 0 and less than an energy value of the first high frequency band signal,
Switching method. A switching device for switching speech or audio signals,
M is greater than or equal to 1, and when switching of speech or audio occurs, weights the first high frequency band signal of the current frame of the speech or audio signal and the second high frequency band signal of the previous M frame of the speech or audio signal, A processing module configured to obtain a processed first high frequency band signal; And
A first synthesis module configured to synthesize the processed first high frequency band signal and a first low frequency band signal of a current frame of a speech or audio signal into a wide frequency band signal
Containing
Switching device. The method of claim 10,
A second synthesis module configured to synthesize the first high frequency band signal and the first low frequency band signal into the wide frequency band signal when speech or audio switching does not occur
Containing more
Switching device. The method according to claim 10 or 11, wherein
When switching from a wide frequency band speech or audio signal to a narrow frequency band speech or audio signal occurs, the processing module is configured to:
A prediction module configured to predict fine structure information and envelope information corresponding to a first high frequency band signal of a current frame of the speech or audio signal;
Configured to weight first predicted envelope information and previous M frame envelope information corresponding to a second high frequency band signal of a previous M frame of the speech or audio signal to obtain first envelope information corresponding to the first high frequency band signal. A first generation module; And
A second generation module configured to generate the processed first high frequency band signal according to the first envelope information and the predicted microstructure information
Including,
Switching device. The method of claim 12,
A classification module configured to classify a first low frequency band signal of the current frame of the speech or audio signal
More,
The prediction module is further configured to predict the microstructure information and envelope information according to the signal type of the first low frequency band signal.
Switching device. The method of claim 12,
The first synthesis module,
A first determining module, configured to determine whether the processed first high frequency band signal needs to be attenuated according to a current frame of speech or audio signal and a previous frame of speech or audio signal before switching;
A third configured to synthesize the processed first high frequency band signal and the first low frequency band signal into the wide frequency band signal when the first determining module determines that the processed first high frequency band signal does not need to be attenuated Synthetic modules;
And when the first determining module determines that the processed first high frequency band signal needs to be attenuated, it is configured to determine whether an attenuation factor corresponding to the processed first high frequency band signal is greater than a predetermined threshold. 2 judgment module;
And when the second determining module determines that the attenuation factor is not greater than the predetermined threshold, multiplies the processed first high frequency band signal by the threshold and multiplies the product and the first low frequency band signal by the wide frequency band. A fourth synthesis module configured to synthesize into a signal;
And when the second determining module determines that the attenuation factor is greater than the predetermined threshold, multiplies the processed first high frequency band signal by the attenuation factor and multiplies the product and the first low frequency band signal by the wide frequency band signal. A fifth synthesis module configured to synthesize with; And
A first modification module configured to modify the damping factor to reduce the damping factor
Including,
The initial value of the attenuation factor is 1, the threshold is greater than or equal to 0 and less than 1,
Switching device. The method according to claim 10 or 11, wherein
When switching from a narrow frequency band speech or audio signal to a wide frequency band speech or audio signal occurs, the processing module may:
A first calculation module configured to calculate the processed first high frequency band signal by weighting according to the set fourth weight 1 and the set fourth weight 2; And
A second modification module, configured to decrease the fourth weight 1 according to a third weighting step and increase the fourth weight 2 according to the third weighting step until the fourth weight 1 becomes zero.
Including,
The fourth weight 1 indicates a weight value of the second high frequency band signal, and the fourth weight 2 indicates a weight value of the first high frequency band signal,
The sum of the fourth weight 1 and the fourth weight 2 is 1,
Switching device. The method of claim 13,
When switching from a narrow frequency band speech or audio signal to a wide frequency band speech or audio signal occurs, the processing module may:
A second calculation module configured to calculate the processed first high frequency band signal by weighting according to a set fifth weight 1 and a set fifth weight 2; And
A third modification module configured to decrease the fifth weight 1 according to a fourth weighting step and increase the fifth weight 2 according to the fourth weighting step until the fifth weight 1 becomes zero.
Including,
The fifth weight 1 indicates a fixed parameter, the fifth weight 2 indicates a weight value of the first high frequency band signal,
The sum of the fifth weight 1 and the fifth weight 2 is 1,
The fixed parameter is a constant greater than or equal to 0 and less than an energy value of the first high frequency band signal,
Switching device.

Images