In recent years, wireless communication between different electronic devices is very popular. However, signal loss, such as packet loss, may happen when an electronic device receives signals from another electronic device. Accordingly, the electronic device which receives signals from another electronic device may use some concealment algorithms to compensate the lost signal. However, the electronic device always uses a single concealment algorithm but different concealment algorithms may have different disadvantages. For example, a weak concealment algorithm (or named a light weight concealment algorithm) consumes less power but could not compensate long continuous signal loss well. On the contrary, a strong concealment algorithm (or named a heavy weight concealment algorithm) can better compensate long continuous signal loss but consumes more power.
Accordingly, a new signal loss compensation method is needed.
One objective of the present application is to provide a signal loss compensation method which can use more than one signal loss concealment algorithms and has lower power consumption.
Another objective of the present application is to provide a signal smooth method which can improve the discontinuity of signals.
One embodiment of the present application discloses a signal loss compensation method, for compensating an input signal comprising (K+Y) lost signal units and at least one normal signal unit. The signal loss compensation method comprises: compensating 1st to (K−1)th ones of the lost signal units by a first signal loss concealment algorithm to generate a first compensation signal and generating a first synthetic signal according to the first compensation signal; compensating (K+X+1)th to (K+Y)th ones of the lost signal units by a second signal loss concealment algorithm to generate a second compensation signal and generating a second synthetic signal according to the second compensation signal; compensating K th to (K+X)th ones of the lost signal units by at least one of the first signal loss concealment algorithm and a second signal loss concealment algorithm to generate a third synthetic signal; generating an output signal according to the first synthetic signal, the second synthetic signal, the third synthetic signal and the normal signal unit. K and Y are positive integers, X is a natural number, and Y is larger than X. A signal loss concealment ability of the second signal loss concealment algorithm is higher than a signal loss concealment ability of the first signal loss concealment algorithm.
Another embodiment of the present application discloses a signal smooth method, comprising: processing a target signal via a signal loss concealment algorithm to generate a compensation signal, according to a reserved part of the target signal; generating a pseudo signal according to a reference part of the target signal, wherein the reference part comprises the reserved part, and a signal length of the reference part is larger than a signal length of the reserved part; combining the pseudo signal and the target signal to generate a pre-smooth signal; and combining the pre-smooth signal and the compensation signal to generate a smooth signal.
In view of above-mentioned embodiments, the input signal can be compensated by the signal loss compensation method which has a good signal concealment ability while consuming less power. Also, the signal discontinuity can be compensated by the signal smooth method to further increase the efficiency of signal compensation.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
Several embodiments are provided in following descriptions to explain the concept of the present invention. Each component in following descriptions can be implemented by hardware (e.g. a device or a circuit) or hardware with software (e.g. a program installed to a processor). Besides, the method in following descriptions can be executed by programs stored in a non-transitory computer readable recording medium such as a hard disk, an optical disc or a memory. Additionally, the term “first”, “second”, “third” in following descriptions are only for the purpose of distinguishing different one elements, and do not mean the sequence of the elements. For example, a first device and a second device only mean these devices can have the same structure but are different devices.
Also, in following embodiments, an audio signal is used as an example for explaining. However, the audio signal can be replaced by any other type of signal. Further, packets are used as an example for explaining. However, the packets can be replaced by any other signal unit.
In one embodiment, a packet loss concealment ability of the second SLC algorithm LC_2 is higher than a packet loss concealment ability of the first SLC algorithm LC_1. Accordingly, the first SLC algorithm LC_1 can be regarded as a light weight packet loss concealment and the second SLC algorithm LC_2 can be regarded as a heavy weight packet loss concealment. In such case, a power consumption of the second SLC algorithm LC_2 is higher than a power consumption of the first SLC algorithm LC_1.
In one embodiment, the first SLC algorithm LC_1 may be an insertion method or a prediction method. The insertion method may be zero-filling and packet reception. For zero-filling, each lost packet is filled with silence signal, as for packet repetition each lost packet would repeat the previous normal packet. The prediction method may be a Pitch-based method or a Linear Prediction method. For Pitch-based method, each lost packet computes pitch period first then output the specific pitch period signal from the previous packet. As for Linear Prediction method, each lost packet uses Linear Prediction Filter Coefficients to synthesize lost packets. Also, in one embodiment, the second SLC algorithm LC_2 may be a neural-network based PLC models, such as WaveRNN, U-Net or Generative Adversarial Network (GAN) based model. However, the first SLC algorithm LC_1 and the second SLC algorithm LC_2 are not limited to these examples.
Detail steps of the signal compensation method in
In the embodiment of
Besides, in the embodiment of
Next, the signal blender Sb generates an output signal OS according to the first synthetic signal SS_1, the second synthetic signal SS_2, the third synthetic signal SS_3 and the normal packets. Specifically, in one embodiment, the first synthetic signal SS_1, the second synthetic signal SS_2, the third synthetic signal SS_3 are used to fill the locations of the lost packets. Accordingly, in such case, the output signal OS is a signal which comprises the normal packets NP of the input signal IS and the packets corresponding to the first synthetic signal SS_1, the second synthetic signal SS_2, and the third synthetic signal SS_3.
Please note, the scope of the present application is not limited to the embodiment of
Based upon the embodiments illustrated in
As above-mentioned, X can be a natural number. Accordingly, in the embodiment of
In the embodiment of
Besides, following the rule depicted in
In one embodiment, the first synthetic signal SS_1 can be generated according the first compensation signal CS_1 and another signal. For example, in the embodiment of
The pseudo signal generator 501 generates a pseudo signal PS according to a reference part of the target part NP_TP. The reference part comprises a reserved part of the target part NP_TP. In one embodiment, a signal length of the reference part is larger than a signal length of the reserved part, but not limited. The pre-smoothor 503 combines the pseudo signal PS and the target part NP_TP to generate a pre-smooth signal Pres. Details of the reference part, the reserved part and the target part NP_TP will be described later. The post-smoothor 505 combines the pre-smooth signal Pres and the first compensation signal CS to generate a portion of the output signal OS. For example, the post-smoothor 505 combines the pre-smooth signal Pres and the first compensation signal CS to generate a portion of the first synthetic signal SS_1. In one embodiment, the first signal loss concealment algorithm LC_1 generates the first compensation signal CS_1 according to the reserved part RE, but not limited.
In one embodiment, the pseudo signal PS comprises a first pseudo part PS_P1 and a second pseudo part PS_P2 following the first pseudo part PS_P1, wherein a length of the first pseudo part PS_P1 is identical with a length of the reserved part RE. In the embodiment of
The arrangement of the first pseudo part PS_P1 and the second pseudo part PS_P2 is not limited to the example illustrated in
In view of above-mentioned embodiments, a signal compensation method can be acquired, which is for compensating an input signal comprising (K+Y) lost signal units (e.g., lost packets) and at least one normal signal unit (e.g., normal packets). The method comprises following steps of
Compensate 1st to (K−1)th ones of the lost signal units by a first signal loss concealment algorithm (e.g., first SLC algorithm LC_1) to generate a first compensation signal (e.g., the first compensation signal CS_1) and generating a first synthetic signal (e.g., the first synthetic signal SS_1) according to the first compensation signal.
Compensate (K+X+1)th to (K+Y)th ones of the lost signal units by a second signal loss concealment algorithm (e.g., second SLC algorithm LC_2) to generate a second compensation signal (e.g., the second compensation signal CS_2) and generating a second synthetic signal (e.g., the second synthetic signal SS_2) according to the second compensation signal.
Compensating K th to (K+X)th ones of the lost signal units by at least one of the first signal loss concealment algorithm and a second signal loss concealment algorithm to generate a third synthetic signal (e.g., the third compensation signal CS_3).
K and Y are positive integers, X is a natural number, and Y is larger than X. A signal loss concealment ability of the second signal loss concealment algorithm is higher than a signal loss concealment ability of the first signal loss concealment algorithm. Other detail steps can be acquired in view of above-mentioned embodiments, thus are omitted for brevity here.
The signal smoothor 401 disclosed in above-mentioned embodiments can be used to process any other signal rather than the signals illustrated in
Process a target signal via a signal loss concealment algorithm to generate a compensation signal, according to a reserved part of the target signal.
In the embodiment of
Generate a pseudo signal according to a reference part of the target signal, such as the embodiments illustrated in
The reference part comprises the reserved part, and a signal length of the reference part is larger than a signal length of the reserved part
Combine the pseudo signal and the target signal to generate a pre-smooth signal.
Combine the pre-smooth signal and the compensation signal to generate a smooth signal.
The operations of the steps 1005 and 1007 can be, for example, the operations illustrated in
As above-mentioned, an original input signal can be transmitted from a source device to a target device, and the above-mentioned input signal IS is the signal which the target device really receives.
The target device TD may acquire information related with the lost packets LP via various methods. For example, the source device SD may transmit a list to inform the target device TD how many packets should be received and the sequence of the packets in the original input signal OIS, thus the target device TD may acquire the information of the lost packets LP. However, the method of acquire information related with the lost packets LP may be changed corresponding the communication algorithm (wireless or wired) between the source device SD and the target device TD.
In one embodiment, the original input signal OIS may be an audio signal. In such case, the source device SD may be an audio source such as a computer or a mobile phone, and the target device TD may be a device which can play the audio signals, such as an earphone or a speaker. Via the above-mentioned signal compensation method, the user which uses the target device TD may have a better user experience since the lost packets are compensated and the signal discontinuity may be improved. However, the original input signal OIS and the input signal IS may be any other type of signals.
In view of above-mentioned embodiments, the input signal can be compensated by the signal loss compensation method which has a good signal concealment ability while consuming less power. Also, the signal discontinuity can be compensated by the signal smooth method to further increase the efficiency of signal compensation.
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
This application claims the benefit of U.S. Provisional Application No. 63/490,802, filed on Mar. 17, 2023. The content of the application is incorporated herein by reference.
Number | Date | Country | |
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63490802 | Mar 2023 | US |