KR20200020491A - Network speaker system and operating method therefore - Google Patents

Abstract

Disclosed are a network speaker system and a method of operating the same which can prevent an asynchronous sound generated between a plurality of network speakers due to network packet delay and hardware clock deviation. The network speaker system comprises: a master speaker including a synchronization module having a reference time for synchronization and a first playback module which reproduces a sound packet according to the reference time and outputs the sound packet by sound; and a slave speaker including a second playback module which configures a local network with the master speaker and plays the sound packet according to a system time synchronized with the reference time and outputs sound.

Description

NETWORK SPEAKER SYSTEM AND OPERATING METHOD THEREFORE}

The present invention relates to a network system and a method of operating the same. More particularly, the present invention relates to a network speaker system and a method for operating the same, which can prevent sound asynchronous between a plurality of network speakers due to network packet delay and hardware clock deviation. It is about.

Recently, the use of wired and wireless networks is becoming more and more common in various fields of living, and according to this trend, network speaker systems in which a plurality of speakers constituting an audio system are networked are being actively developed.

The network speaker system is based on the synchronization concept that the network speakers start to reproduce the same audio data at the same time point through the same time setting with each other so that the sound outputted by each is the same.

However, when the actual network speaker system is operated, the sound playback starts the same at the same time, but the time of each network speaker is different after a certain time due to the hardware clock deviation between the network speakers. There is a problem that the synchronization of the sound output from the speaker is broken.

In addition to the problem caused by the difference in the hardware clock, even if there is a packet delay on the network, the sound output from each network speaker is different from each other, there is a problem that the sound source is not naturally reproduced.

The matters described as the background art are only for the purpose of improving the understanding of the background of the present invention, and should not be taken as acknowledging that they correspond to the related art already known to those skilled in the art.

Accordingly, the present invention provides a network speaker system and a method for operating the same, which can prevent asynchronous sound generated between a plurality of network speakers through time synchronization and audio data correction between the plurality of network speakers. do.

The present invention as a means for solving the above technical problem,

A master speaker including a synchronization module having a reference time for synchronization and a first playback module for reproducing and outputting sound packets according to the reference time; And

A slave speaker comprising a second reproducing module constituting a local network with the master speaker and reproducing a sound packet as a sound according to a system time synchronized to the reference time;

It provides a network speaker system comprising a.

In one embodiment of the present invention, the second reproducing module writes a first time for creating a time packet and transmits a time packet based on the system time to the synchronization module and transmits the first time to the synchronization module. The synchronization module receives the second time when the time packet is received based on the reference time, records the time packet in the time packet, and transmits the same to the second playback module. The reference time may be calculated based on a second time and a third time of receiving the time packet from the synchronization module, and the system time may be updated with the calculated reference time.

In one embodiment of the present invention, the second regeneration module has the following formula

The reference time can be calculated by.

In an embodiment of the present disclosure, the updating may include the second playback module updating the system time to the reference time when the difference between the third time and the first time is equal to or greater than a preset level.

In one embodiment of the present invention, the second playback module may modify the playback position of the sound data to be played back based on the time error between the system time and the calculated reference time before updating the system time.

As another means for solving the above technical problem, the present invention,

As a method of operating the network speaker system described above,

The synchronization module broadcasting a synchronization execution request;

Receiving, by the second playback module, receiving the synchronization execution request, creating a time packet and recording a first time for transmitting the time packet to the time packet and transmitting the time packet to the synchronization module;

Recording, by the synchronization module, a second time when the time packet is received in the time packet and transmitting to the second playback module; And

Calculating, by the second reproducing module, the reference time based on the third time when the time packet is received and the first time and the second time; And

Updating, by the second playback module, the system time to the reference time

It provides a method of operating a network speaker system comprising a.

In one embodiment of the present invention, the broadcasting of the synchronization execution request may include: when the speaker network is initially configured, when a reference time set in the synchronization module is changed, when the speaker network is disconnected and then connected again. It may be performed in at least one of the cases in which the preset time interval elapses after the updating step.

In one embodiment of the invention, in the calculating step, the second playback module is

The reference time can be calculated by.

In an embodiment of the present disclosure, the updating may include the second playback module updating the system time to the reference time when the difference between the third time and the first time is equal to or greater than a preset level.

In one embodiment of the present invention, the updating may include: reproducing the second playback module based on a time error between the system time and the calculated reference time before updating the system time to the calculated reference time. The method may include modifying a play position of sound data.

According to the network speaker system and its operation method, in the network speaker system consisting of a master speaker and a slave speaker, time synchronization and sound synchronization are performed by transmitting and receiving time packets between the master speakers, thereby causing an error and a packet delay of a hardware clock. Thereby, there is an excellent effect of preventing the synchronization between the network speakers to be broken and enabling natural sound source reproduction.

1 is a block diagram showing a network speaker system according to an embodiment of the present invention.
2 is a flowchart illustrating a method of operating a network speaker system according to an embodiment of the present invention.

Hereinafter, a network speaker system and a method of operating the same according to various embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing a network speaker system according to an embodiment of the present invention.

Referring to FIG. 1, a network speaker system according to an embodiment of the present invention may include a plurality of network speakers 10, 20a, and 20b constituting a local Internet Protocol (IP) network. Each network speaker 10, 20a, 20b may have its own IP address, and the network speaker 10 having the IP address list 17 of the network speakers among the network speakers 10, 20a, 20b is sound data. The master speaker to transmit the remaining network speakers (20a, 20b) may be a slave speaker receiving sound data from the master speaker.

The master speaker 10 has a reference time for synchronization and communicates with the slave speakers 20a and 20b to synchronize the synchronization module 11 and reproduces the sound data with the playback module of each network speaker 10, 20a and 20b ( It may include a data transmission module 13 for transmitting to the 15, 25a, 25b and a reproduction module 15 for reproducing sound data according to the reference time and outputting the sound.

The slave speakers 20a and 20b may include reproducing modules 25a and 25b that reproduce sound data transmitted from the data transmission module 13 of the master speaker 10 and output the sound according to the system time. Here, the playback modules 25a and 25b of the slave speakers 20a and 20b may communicate with the synchronization module 11 of the master speaker 10 to synchronize the system time to the reference time, and between the system time and the reference time. Sound synchronization may be performed by adjusting sound data to be reproduced according to a time error.

In FIG. 1, the master speaker 10 is illustrated as including a synchronization module 11, a data module 13, and a playback module 15 for convenience of description, and the slave speakers 20a and 20b are represented by a playback module 25a, Although illustrated as including only 25b), all network speakers 10, 20a, and 20b may include a synchronization module 11, a data module 13, and a playback module 15. However, in the multi mode in which the network speakers 10, 20a, and 20b are synchronized and played together, one speaker having the IP address list 17 becomes the master speaker, and the synchronization module 11, the data module 13, and the playback module The configuration shown in FIG. 1 may be implemented by all of the 15 being activated and the remaining slave speakers having their synchronization modules and data modules deactivated.

According to various embodiments of the present invention, time synchronization for synchronizing the system time of the slave speakers 20a and 20b with the reference time of the synchronization module 11 of the master speaker 10, and the error between the reference time and the system time. Sound synchronization is performed to remove a difference in the sound output when the sound data is played.

The operation and effect of each component of the network speaker system according to an embodiment of the present invention shown in FIG. 1 will be more clearly explained through an operation method of the network speaker system according to an embodiment of the present invention described below. It can be understood.

2 is a flowchart illustrating a method of operating a network speaker system according to an embodiment of the present invention. In particular, a method of operating a network speaker system according to an embodiment of the present invention shown in FIG. 2 is to perform synchronization of time and sound between a plurality of network speakers.

Referring to FIG. 2, a method of operating a network speaker system according to an exemplary embodiment of the present invention includes first reproducing modules 25a and 25b in each slave speaker 20a and 20b in the synchronization module 11 of the master speaker 10. ) May be started from the step S11 of requesting synchronization execution.

This synchronization execution request step S11 is included in the list 17 by the synchronization module 11 of the master speaker 10 with reference to the IP address list 17 of each slave speaker 20a, 20b included in the speaker network. It can be implemented by broadcasting the synchronization execution request to the slave speaker (20a, 20b) having the IP address.

The synchronization module 11 of the master speaker 10 corresponds to a time point when the initial speaker network is configured, a time point when the time set in the synchronization module 11 is changed, a time point when the speaker network is disconnected and reconnected, and a preset time interval. At this point in time, the synchronization execution request step S11 may be executed to perform a synchronization process as shown in FIG. 2.

In particular, performing synchronization at preset time intervals enables correction of deviations in synchronization after a certain period of time due to hardware clock deviations between network speakers 10, 20a, 20b.

Subsequently, each of the playback modules 25a and 25b in the slave speakers 20a and 20b that have received the synchronization execution request from the synchronization module 11 of the master speaker 10 has a current time t1 at which it has received the synchronization execution request. The recorded time packet is created and transmitted to the synchronization module 11 of the master speaker 10 (S12).

As described above, each of the playback modules 25a, 25b in the slave speakers 20a, 20b has a preset system time, and according to the respective system time, the current time t1 for which it creates a time packet and transmits a time packet. ) Is recorded in the time packet and transmitted to the synchronization module 11 of the master speaker 10 (S12).

On the other hand, if the slave speakers 20a, 20b are not activated when the synchronization module 11 of the master speaker 10 broadcasts the synchronization execution request in step S11, the slave speakers 20a, 20b thereafter. When the playback modules 25a and 25b receive the sound packet including the sound data, the reproduction module 25a or 25b may check the IP address of the master speaker 10 included in the sound packet to create and transmit a time packet.

Subsequently, the synchronization module 11 of the master speaker 10 receives from the playback modules 25a and 25b in each of the slave speakers 20a and 20b, and the current time t2 when the time packet is received by the received time packet. ) Is recorded and transmitted back to the playback modules 25a and 25b in the corresponding slave speakers 20a and 20b (S13).

As described above, the synchronization module 11 of the master speaker 10 has a reference time set to the master speaker 10 and records the current time t2 at which the time packet is received based on the reference time in the received time packet and then records the time packet. Is transmitted to the reproduction modules 25a and 25b in the slave speakers 20a and 20b which have been transmitted (S13).

Subsequently, the playback modules 25a and 25b in the slave speakers 20a and 20b have the two current times described above, that is, the time t1 at which they have received a synchronization execution request and the synchronization module 11 of the master speaker 10. The time of the synchronization module 11 of the master speaker 10 using the time t2 of receiving the time packet and the time t3 of receiving the time packet again from the synchronization module 11 of the master speaker 10, That is, the reference time is calculated (S14).

For example, in step S14, the playback modules 25a and 25b in the slave speakers 20a and 20b set the reference time T _ref of the synchronization module 11 of the master speaker 10 as shown in Equation 1 below. Can be calculated.

[Equation 1]

The second term on the right side in Equation 1 is to generate a time packet immediately after the playback module 25a, 25b in the slave speakers 20a, 20b receives the synchronization request, and transmit the time packet to the synchronization module 11, and the synchronization module 11 It corresponds to half of the time taken from the time of receiving the time packet back to the time packet.

If there is no network delay, immediately after the playback modules 25a and 25b in the slave speakers 20a and 20b receive the synchronization request, a time packet is created and transmitted to the synchronization module 11 and the time packet is sent from the synchronization module 11 again. The time (t3-t1) until the moment of reception may be negligibly small, but if the value of "t3-t1" is greater than a certain level, it may be determined that a network delay has occurred.

Therefore, in step S14, the playback modules 25, 25a, and 25b of the network speakers 10, 20a, and 20b create a time packet immediately after receiving the synchronization request, transmit the time packet to the synchronization module 11, and the synchronization module ( If the time (t3-t1) until the time packet is received again from 11) becomes more than a preset level, the reference time is calculated using Equation 1.

Subsequently, the playback modules 25a and 25b in the slave speakers 20a and 20b update their system time to the reference time to complete time synchronization (S15).

When sound data is not reproduced through the network speakers 10, 20a, and 20b, the reference time is calculated through the process of steps S11 to S14 as described above, and the reproduction in the slave speakers 20a and 20b is performed. After the time synchronization is completed by updating the modules 25a and 25b to the reference time, sound synchronization may be performed by using the updated system time when playing sound data.

However, while sound data is being reproduced through the network speakers 10, 20a, and 20b, not only the time synchronization but also the synchronization of the sound being reproduced must be performed together. To this end, when sound data is being reproduced through the network speakers 10, 20a, and 20b, step S15 is performed by comparing the reference time calculated before the system time with the calculated reference time and the system time before the update. The playback position of the sound data can be corrected based on the difference.

That is, in step (S15), reproduction module (25a, 25b) in the slave speaker (20a, 20b) is such as to a time offset (T _△) of the calculation reference time and their system time (T _sys) Equation 2 After retrieval, sound synchronization is performed by modifying the playback position of sound data according to time error.

[Equation 2]

According to Equation 2, when the time error T _Δ is a positive value, the master speaker 10 having the synchronization module 11 that provides the reference time is as much as the time error T _Δ than the slave speakers 20a and 20b. Since that is first reproduced sound data, the reproduction module (25a, 25b) in the slave speaker (20a, 20b) is by a time error (T _△) by moving the reproduction position by the sound data in the backward (time offset (T _△) Perform sound synchronization) by cutting the sound data.

On the contrary, when the time error T _Δ is negative, the slave speakers 20a and 20b play sound data earlier by the time error T _Δ than the master speaker 10 having the synchronization module 11 that provides the reference time. Since that is, the reproduction module (25a, 25b) in the slave speaker (20a, 20b) by adding the sound data as to move forward the playback position of the sound data by a time error (T _△) (timing offset (T _△) Perform a sound synchronization

As such, while sound data is being reproduced through the network speakers 10, 20a, and 20b in step S15, first, the sound is synchronized based on the time error _TΔ , and then the system time is updated. Time synchronization can be completed.

As described above, the network speaker system and its operation method according to various embodiments of the present invention, in the network speaker system consisting of a master speaker and a slave speaker, time synchronization and sound through time transmission and reception between the master speakers By performing the synchronization, the synchronization between the network speakers is prevented from being broken by the error of the hardware clock and the packet delay, and the natural sound source can be reproduced.

While shown and described in connection with specific embodiments of the present invention, it is understood that the present invention can be variously modified and changed without departing from the technical spirit of the present invention provided by the claims below. It will be apparent to those of ordinary skill in the art.

10: master speaker 11: synchronization module
13: data transmission module 15: first playback module
17: IP address list 20a, 20b: slave speaker
25a, 25b: second playback module

Claims (10)

A master speaker including a synchronization module having a reference time for synchronization and a first playback module for reproducing and outputting sound packets according to the reference time; And
A slave speaker comprising a second reproducing module constituting a local network with the master speaker and reproducing a sound packet as a sound according to a system time synchronized to the reference time;
Network speaker system comprising a. The method according to claim 1,
The second reproducing module writes a time packet and records a first time of transmitting a time packet based on the system time in the time packet, and transmits the time packet to the synchronization module. The second time receiving the time packet based on a reference time is recorded in the time packet and transmitted to the second reproducing module, wherein the second reproducing module is provided from the first time, the second time, and the synchronization module. And calculating the reference time based on the third time when the time packet is received, and updating the system time with the calculated reference time. The method according to claim 2,
The second regeneration module has the following formula

And the reference time is calculated by using T _ref : reference time, t1: first time, t2: second time, and t3: third time. The method according to claim 2,
The updating may include the second playback module updating the system time to the reference time when the difference between the third time and the first time is greater than or equal to a preset level. The method according to claim 2,
And the second reproducing module modifies the reproducing position of sound data to be reproduced based on a time error between the system time and the calculated reference time before updating the system time. In the operating method of the network speaker system of claim 1,
The synchronization module broadcasting a synchronization execution request;
Receiving, by the second playback module, receiving the synchronization execution request, creating a time packet and recording a first time for transmitting the time packet to the time packet and transmitting the time packet to the synchronization module;
Recording, by the synchronization module, the second time when the time packet is received in the time packet and transmitting to the second playback module; And
Calculating, by the second playback module, the reference time based on the third time when the time packet is received, the first time, and the second time; And
Updating, by the second playback module, the system time to the reference time
Operating method of a network speaker system comprising a. The method according to claim 5,
The broadcasting of the synchronization execution request may include: when a speaker network is initially configured, when a reference time set in the synchronization module is changed, when a speaker network is disconnected and then reconnected, and a preset time after performing the updating step. A method of operating a network speaker system, characterized in that performed in at least one of the cases in which the interval has passed. The method according to claim 5,
The calculating may be performed by the second regeneration module.

And calculating the reference time by using T _ref : reference time, t1: first time, t2: second time, and t3: third time. The method according to claim 5,
The updating may include the second playback module updating the system time to the reference time when the difference between the third time and the first time is greater than or equal to a preset level. The method according to claim 5,
The updating may include modifying a playback position of sound data to be played based on a time error between the system time and the calculated reference time before the second playback module updates the system time with the calculated reference time. Method of operating a network speaker system comprising the step of.

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