Method for realizing point-to-multipoint visual intercom

Abstract

The invention discloses a point-to-multipoint visual intercom method in the building field, and aims to solve the technical problems of over-high bandwidth occupation, large transmission delay, inconsistent multi-terminal synchronization and disordered authority management during point-to-multipoint intercom in the prior art. According to the method, multi-terminal communication connection is established through a talkback management server, bandwidth is dynamically allocated based on terminal attributes and network states, visual talkback data is scheduled in combination with hierarchical authority, and multi-terminal real-time interaction is achieved through a progressive synchronous correction mechanism. Experimental verification shows that the method can reduce the total bandwidth occupation of point-to-multipoint talkback by more than 47%, control the transmission delay within 80ms, the synchronization error less than 10ms and the lagging rate less than 1%, and is suitable for a multi-terminal visual talkback system in scenes such as building communities, office buildings and the like.

Description

Technical Field

[0001] This invention relates to the field of building intelligent communication technology, specifically a method for realizing point-to-multipoint visual intercom. Background Technology

[0002] With the development of building intelligence, video intercom systems have become core equipment for building security and communication, and are widely used in scenarios such as communication between residents and visitors, property management, and emergency notifications.

[0003] Existing video intercom systems mostly adopt point-to-point communication. When point-to-multipoint communication (such as a door station simultaneously communicating with multiple resident indoor units and property management units) is required, the following technical defects exist: 1. High bandwidth consumption: Using a fixed bandwidth allocation method, each terminal occupies the same bandwidth resources. When multiple terminals communicate simultaneously, the total bandwidth demand increases linearly, easily leading to network congestion; 2. Large transmission delay: Lacking a priority scheduling mechanism, important terminals (such as property management units) transmit data indistinguishably from ordinary terminals, and the dynamic adjustment of network status is not considered, resulting in delays in the transmission of critical information; 3. Inconsistent synchronization among multiple terminals: The local time of each terminal deviates, and video frame playback is out of sync, affecting the user's intercom experience; 4. Chaotic access control: Without clear access control layers, visitor terminals may arbitrarily access multiple intercom links, posing security risks.

[0004] In existing technologies, some solutions attempt to alleviate the above problems by increasing network bandwidth or simplifying video data, but they do not address the collaborative mechanisms of bandwidth allocation, permission scheduling, and synchronization correction. Therefore, they cannot fundamentally solve the core technical pain points of point-to-multipoint intercom. Thus, a technical solution with dynamic adaptability and collaborative optimization is urgently needed. Summary of the Invention

[0005] The purpose of this section is to outline some aspects of the embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0006] Therefore, the purpose of this invention is to provide a method for realizing point-to-multipoint video intercom, so as to solve the problems mentioned in the background art.

[0007] To address the aforementioned technical problems, according to one aspect of the present invention, the present invention provides the following technical solution: A method for implementing point-to-multipoint video intercom includes the following steps: S1. Receive at least one point-to-multipoint intercom request from an initiating terminal through the intercom management server. The intercom request includes the target terminal set identifier and the intercom service type. S2. The intercom management server obtains the attribute information of each terminal in the initiating terminal and target terminal set, as well as the current network communication status parameters; S3. Based on the terminal attribute information and network communication status parameters, dynamically allocate communication bandwidth resources for each terminal; S4. Based on the preset permission level rules, schedule the priority of visual intercom data transmission between the initiating terminal and the target terminal set; S5. Eliminate the time difference between multiple terminals through a synchronization correction mechanism to achieve real-time visual intercom interaction between the initiating terminal and the target terminal set.

[0008] As a preferred embodiment of the method for implementing point-to-multipoint video intercom according to the present invention, the terminal attribute information includes a terminal type weight. Terminal access priority (P), video data volume requirement (D); The network communication status parameters include the total available network bandwidth B. total Network latency τ, packet loss rate η.

[0009] As a preferred embodiment of the method for implementing point-to-multipoint visual intercom according to the present invention, in step S3, the dynamic allocation of communication bandwidth is specifically calculated as follows: ; in: Bandwidth is allocated for the i-th terminal, n is the total number of terminals participating in the intercom, and k is the bandwidth allocated for the i-th terminal. reserve A bandwidth reserve factor, ranging from 0.85 to 0.95, is used to mitigate network fluctuations. The type weight of the i-th terminal. Let i be the access priority of the i-th terminal. Let be the video data requirement of the i-th terminal; be the network packet loss rate; and τ be the network latency. Correct the impact of network status on bandwidth allocation.

[0010] In a preferred embodiment of the method for implementing point-to-multipoint video intercom according to the present invention, step S4 includes three levels of permissions: Administrator level, permission value Q=3, allows initiating full terminal intercom, interrupting any intercom link, and adjusting permissions of other terminals; Authorization level, permission value Q=2, allows initiating terminal intercom within a preset range, receiving all intercom requests, and sharing local video data; Guest level, permission Q=1, only allowed to communicate with the specified target terminal, only allowed to receive video data from the initiating terminal, no data sharing permission; Data transmission priority ,in Let be the permission value for the i-th terminal. Let be the transmission delay of the i-th terminal. The larger the value, the higher the data transmission priority.

[0011] In a preferred embodiment of the method for implementing point-to-multipoint video intercom according to the present invention, the calculation of the synchronization correction mechanism in step S5 is as follows: ; in: Let i be the local timestamp of the i-th terminal. The standard timestamp for the intercom management server; Let be the time synchronization error of the i-th terminal, and α be the asymptotic correction coefficient, with a value ranging from 0.15 to 0.3. Let i be the corrected timestamp of the i-th terminal. Iterative correction is used to make all terminals... and The difference is less than 10ms.

[0012] As a preferred embodiment of the method for implementing point-to-multipoint video intercom according to the present invention, the video data volume requirement is... Dynamically adjusted through an adaptive compression algorithm The formula for calculating the compression ratio is: in: The baseline compression ratio is 15-25. This represents the current bandwidth usage of the i-th terminal. Allocate bandwidth for the i-th terminal. Let be the packet loss rate of the i-th terminal; when hour, Automatically increases in size, reducing the amount of video data; When the r value is used, it automatically decreases to improve video clarity.

[0013] In a preferred embodiment of the point-to-multipoint video intercom method described in this invention, in step S2, the intercom management server updates network status parameters through a periodic detection mechanism, with a detection period T=200ms. The detection process includes: Send probe data packets to each terminal and record the data packet sending time t. send and the response time t recv ; Calculate network latency The packet loss rate η is obtained by statistically analyzing the percentage of lost probe data packets. The remaining bandwidth of the network router is obtained through the SNMP protocol, which is used as the total available network bandwidth B. total。 As a preferred embodiment of the point-to-multipoint video intercom method described in this invention, the permission level rules support dynamic adjustment, the adjustment command is initiated by the administrator-level terminal, and the adjustment takes effect at a specific time. Q target The adjusted target permission value; the higher the permission level, the shorter the effective time.

[0014] As a preferred embodiment of the method for realizing point-to-multipoint video intercom according to the present invention, the synchronization correction mechanism further includes video frame synchronization correction, and the correction formula is as follows: in: T is the sequence number of the video frame currently being played on the i-th terminal. frame The video frame interval is represented by `round()`, which is the rounding function. Let T be the corrected video frame number of the i-th terminal, ensuring that the time difference between all terminals playing the same video frame is less than T. frame。 As a preferred embodiment of the method for implementing point-to-multipoint video intercom as described in this invention, wherein the total available network bandwidth... In such cases, an emergency bandwidth allocation strategy will be activated: ; At this time, the video data volume requirement Automatically decrease to the lowest threshold D min To ensure basic intercom functionality.

[0015] Compared with existing technologies, the beneficial effects of this invention are as follows: This invention solves the technical defects of point-to-multipoint video intercom in the building field through a collaborative mechanism of dynamic bandwidth allocation, hierarchical permission scheduling, and progressive synchronization correction. Its key lies in: designing a quantitative bandwidth allocation algorithm based on terminal attributes and network status, realizing data transmission priority scheduling in combination with permission levels, and ensuring real-time interaction of multiple terminals through timestamp correction and video frame synchronization. The three form a closed-loop optimization, achieving a comprehensive improvement in bandwidth usage, transmission delay, and synchronization accuracy. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and detailed embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 This is a flowchart of a method for implementing point-to-multipoint video intercom according to the present invention; Figure 2A comparison chart of test indicators between the present invention (experimental group) and the prior art solution (comparison group) provided for the present invention. Detailed Implementation

[0017] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0018] like Figure 1 As shown, the specific steps of the method for realizing point-to-multipoint video intercom according to the present invention are as follows: S1. Receive at least one point-to-multipoint intercom request from an initiating terminal through the intercom management server. The intercom request includes the target terminal set identifier and the intercom service type. S2. The intercom management server acquires the attribute information of each terminal in the initiating terminal and target terminal sets, as well as the current network communication status parameters; wherein, the terminal attribute information includes terminal type weights. The network communication status parameters include: terminal access priority P, video data volume requirement D; and the total available network bandwidth B. total Network latency τ and packet loss rate η; the intercom management server updates network status parameters through a periodic detection mechanism with a detection period T=200ms. The detection process includes: sending probe data packets to each terminal and recording the data packet sending time t. send and the response time t recv ; Calculate network latency The packet loss rate η is obtained by statistically analyzing the percentage of lost probe data packets; the remaining bandwidth of the network router is obtained via the SNMP protocol and used as the total available network bandwidth B. total S3. Based on the terminal attribute information and network communication status parameters, dynamically allocate communication bandwidth resources for each terminal. The specific calculation for dynamically allocating communication bandwidth is as follows: ; in: Bandwidth is allocated for the i-th terminal, n is the total number of terminals participating in the intercom, and k is the bandwidth allocated for the i-th terminal. reserve A bandwidth reserve factor, ranging from 0.85 to 0.95, is used to mitigate network fluctuations. The type weight of the i-th terminal. Let i be the access priority of the i-th terminal. Let be the video data requirement of the i-th terminal; be the network packet loss rate; and τ be the network latency. Correcting the impact of network status on bandwidth allocation; the video data volume requirement. The compression ratio is dynamically adjusted through an adaptive compression algorithm. The calculation formula is: in: The baseline compression ratio is 15-25. This represents the current bandwidth usage of the i-th terminal. Allocate bandwidth for the i-th terminal. Let be the packet loss rate of the i-th terminal; when hour, Automatically increases in size, reducing the amount of video data; When this happens, r automatically decreases, improving video clarity; When the total available network bandwidth In such cases, an emergency bandwidth allocation strategy will be activated: ; At this time, the video data volume requirement Automatically decrease to the lowest threshold D min To ensure basic intercom functionality.

[0019] S4. According to preset permission level rules, prioritize the video intercom data transmission between the initiating terminal and the target terminal set. The preset permission level rules include three permission levels: Administrator level (Q=3), allowing initiation of intercom with all terminals, interruption of any intercom link, and adjustment of other terminal permissions; Authorized level (Q=2), allowing initiation of intercom with terminals within a preset range, receiving all intercom requests, and sharing local video data; Guest level (Q=1), only allowing intercom with a specified target terminal, only receiving video data from the initiating terminal, and no data sharing permissions; Data transmission priority. ,in Let be the permission value for the i-th terminal. Let be the transmission delay of the i-th terminal. The larger the value, the higher the data transmission priority; the permission level rules support dynamic adjustment, and the adjustment command is initiated by the administrator-level terminal, with the adjustment taking effect after a certain time. Q target The adjusted target permission value; the higher the permission level, the shorter the effective time. S5. Eliminate the time difference between multiple terminals through a synchronization correction mechanism to achieve real-time visual intercom interaction between the initiating terminal and the target terminal set. The calculation of the synchronization correction mechanism is as follows: ; in: Let i be the local timestamp of the i-th terminal. The standard timestamp for the intercom management server; Let be the time synchronization error of the i-th terminal, and α be the asymptotic correction coefficient, with a value ranging from 0.15 to 0.3. Let i be the corrected timestamp of the i-th terminal. Iterative correction is used to make all terminals... and The difference is less than 10ms; the synchronization correction mechanism also includes video frame synchronization correction, the correction formula is: in: T is the sequence number of the video frame currently being played on the i-th terminal. frame The video frame interval is represented by `round()`, which is the rounding function. Let T be the corrected video frame number of the i-th terminal, ensuring that the time difference between all terminals playing the same video frame is less than T. frame .

[0020] To verify the technical effects of the present invention, the following experiments are provided for verification and explanation: 1. Hardware configuration: Intercom management server (CPU i7-12700H, 16GB memory, Gigabit Ethernet); the initiating terminal is the door station (1080P camera, H.265 encoding format); the target terminals include 1 property management unit (1080P) and 8 indoor units (720P); the network environment simulates a building community LAN and supports bandwidth adjustment.

[0021] 2. Control group: using existing technology (fixed bandwidth allocation, no access control scheduling, no synchronization correction); Experimental group: using the technical solution of this invention.

[0022] 3. Test metrics: total bandwidth usage, average transmission latency, maximum synchronization error, stuttering rate (percentage of time with frame rate <15 frames / second), and permission response time.

[0023] like Figure 2 As shown in the experimental data, the present invention reduces the total bandwidth usage by nearly 50% through a dynamic bandwidth allocation algorithm, controls the transmission delay to within 80ms through hierarchical permission scheduling, and reduces the synchronization error to less than 10ms through a synchronization correction mechanism, thereby reducing the stuttering rate to below 1%. It fully meets the real-time and stability requirements of point-to-multipoint video intercom in the building field, and the technical solution has significant feasibility and superiority.

[0024] Although the present invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, as long as there is no structural conflict, the features in the disclosed embodiments can be combined with each other in any manner. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method of implementing point-to-multipoint video intercom, characterized by, The method comprises the following steps: S1, receiving a point-to-multipoint intercom request of at least one initiating terminal through an intercom management server, wherein the intercom request comprises a target terminal set identifier and an intercom service type; S2, the intercom management server acquires attribute information and current network communication state parameters of each terminal in the initiating terminal and the target terminal set; S3, based on the terminal attribute information and the network communication state parameters, dynamically allocating communication bandwidth resources of each terminal; S4, according to a preset authority level rule, scheduling a visual intercom data transmission priority between the initiating terminal and the target terminal set; S5, eliminating time difference between multiple terminals through a synchronous correction mechanism to realize real-time visual intercom interaction between the initiating terminal and the target terminal set.

2. The method for implementing point-to-multipoint visual intercom according to claim 1, characterized in that, The terminal attribute information includes a terminal type weight , a terminal access priority P, and a video data volume demand D. The network communication state parameters include total network available bandwidth , network delay τ, packet loss rate η.

3. The method of claim 2, wherein, In step S3, the dynamically allocated communication bandwidth is specifically calculated as follows: ; in: The bandwidth allocated to the i-th terminal, where n is the total number of terminals participating in the intercom. A bandwidth reserve factor, ranging from 0.85 to 0.95, is used to mitigate network fluctuations. The type weight of the i-th terminal. Let i be the access priority of the i-th terminal. Let be the video data requirement of the i-th terminal; be the network packet loss rate; and τ be the network latency. Correct the impact of network status on bandwidth allocation.

4. The method for implementing point-to-multipoint visual intercom according to claim 1, characterized in that, In step S4, the preset authority level rule comprises three levels of authority: The administrator level has an authority value Q=3, allowing to initiate a full-terminal intercom, interrupt any intercom link and adjust the authority of other terminals; The authorized level has an authority value Q=2, allowing to initiate an intercom within a preset range, receive all intercom requests and share local video data; The visitor level has an authority Q=1, allowing to intercom with only specified target terminals and receive only video data of the initiating terminal, without data sharing authority; Data transmission priority wherein is a priority value for the i-th terminal, is a transmission delay for the i-th terminal, the greater, the higher the data transmission priority.

5. The method for implementing point-to-multipoint visual intercom according to claim 1, characterized in that, In step S5, the calculation of the synchronization correction mechanism is as follows: ; Wherein: is the local timestamp of the ith terminal, is the standard timestamp of the talkback management server; is the time synchronization error of the ith terminal, and a is a gradual correction coefficient, with a value range of 0.15-0.3; is the corrected timestamp of the ith terminal, and through iterative correction, the difference between and is less than 10 ms.

6. The method of claim 3, wherein the method further comprises: The video data amount requirement The compression ratio is dynamically adjusted by the adaptive compression algorithm The calculation formula is: Wherein: is the reference compression ratio, taking a value of 15-25, is the current bandwidth usage of the ith terminal; is the allocated bandwidth of the ith terminal, is the transmission packet loss rate of the ith terminal; When the video data amount is reduced automatically; the video data amount is reduced automatically; the video definition is improved automatically.

7. The method for implementing point-to-multipoint visual intercom according to claim 1, characterized in that, In step S2, the intercom management server updates the network state parameters through a periodic detection mechanism, with a detection period T=200ms, and the detection process comprises: Sending a probe data packet to each terminal, recording the data packet sending time t send And receiving the response time t recv ; Computing network latency The packet loss rate η is obtained by counting the proportion of the number of lost statistical probe packets. Obtaining the residual bandwidth of the network router through the SNMP protocol as the total amount of network available bandwidth .

8. The method for implementing point-to-multipoint visual intercom according to claim 4, characterized in that, The permission level rule supports dynamic adjustment, and the adjustment instruction is initiated by an administrator terminal, and the adjustment takes effect at a time wherein Q target is an adjusted target permission value, and the higher the permission level, the shorter the effective time.

9. The method for implementing point-to-multipoint visual intercom according to claim 5, characterized in that, The synchronous correction mechanism further comprises video frame synchronization correction, and the correction formula is: Wherein: is the current playing video frame number of the ith terminal, T frame is the video frame interval; round() is the rounding function, is the corrected video frame number of the ith terminal, ensuring that the time difference of all terminals playing the same frame of video is less than T frame .

10. The method for implementing point-to-multipoint visual intercom according to claim 3, characterized in that, When the total amount of network available bandwidth the bandwidth emergency allocation strategy is started: ; This time video data amount demand Automatically falls to the minimum threshold D min , guarantee basic talkback function.

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