CN106789268A - A kind of network audio transmission method and system - Google Patents

Abstract

The invention discloses a network audio transmission method, which involves a switch, at least one audio sending device and at least one audio receiving device, the switch, the audio sending device and the audio receiving device are located in the same network segment, and the method is specifically as follows : Step 1: The audio sending device sends the data encapsulated with IP address, audio signal or control signal to the switch; Step 2: The switch receives the data and sends the data to the audio receiving device corresponding to the IP address; Step 3: The audio receiving device receives the data sent by the switch and decapsulates it to obtain an audio signal or a control signal. The purpose of the present invention is to provide a network audio transmission method and system.

Description

Method and system for network audio transmission

technical field

The invention relates to the technical field of network audio transmission, in particular to a network audio transmission method and system.

Background technique

In the prior art, most of the audio needs to be transmitted with the corresponding audio cable as an analog signal. In this case, the disadvantage is that a large number of audio cables need to be connected for connection, and the operation requirements of the operator are high, especially for long-distance data. It is more difficult to transmit it.

Contents of the invention

The purpose of the present invention is to provide a network audio transmission method and system.

The specific technical solution of the present invention is: a network audio transmission method, involving a switch, at least one audio sending device and at least one audio receiving device, the switch, the audio sending device and the audio receiving device are located in the same network segment, so The specific method described is:

Step 1: The audio sending device sends the data encapsulated with IP address, audio signal or control signal to the switch;

Step 2: the switch receives the data and sends the data to the audio receiving device corresponding to the IP address;

Step 3: The audio receiving device receives the data sent by the switch and decapsulates it to obtain an audio signal or a control signal.

In the above-mentioned network audio transmission method, in step 1, the audio sending device and the audio receiving device assign IP addresses through a zero-configuration network protocol or a DHCP server.

In the above-mentioned network audio transmission method, in step 1, the audio sending device encapsulates the audio signal or control signal at the transport layer with a UDP header, at the network layer with the IP address, and at the data link layer Encapsulate the Ethernet header and send it to the physical layer;

After the audio receiving device receives the data sent by the audio sending device at the physical layer, it performs corresponding decapsulation operations at the data link layer, network layer, and transport layer to obtain audio signals or control signals.

In the above network audio transmission method, a synchronous clock signal is also included, the synchronous clock signal is packaged synchronously with the data, and the audio receiving device outputs the audio signal or the control signal at the same reference time according to the synchronous clock signal.

In the above-mentioned network audio transmission method, the audio sending device includes at least one of a microphone, a digital music storage and playback unit, and a DSP digital processor; the audio receiving device includes a stereo, a DSP digital processor, a digital music storage At least one of the playback units.

At the same time, the invention also discloses a network audio transmission system, which includes a switch, one less audio sending device, and at least one audio receiving device. The switch, the audio sending device and the audio receiving device are located in the same network segment, and the The audio sending device is used to encapsulate data including IP address, audio signal or control signal, and send the data to the switch;

The switch is used to receive the data and send the data to the audio receiving device corresponding to the IP address;

The audio receiving device is used to receive the data sent by the switch and decapsulate it to obtain an audio signal or a control signal.

In the above-mentioned network audio transmission system, the audio sending device is also used to package the synchronous clock signal and the data to the switch;

The audio receiving device is used for outputting audio signals or control signals at the same reference time according to the synchronous clock signal.

Compared with prior art, the beneficial effect of the present invention is:

The audio data of the present invention is transmitted in the form of data packets, and the audio data is transmitted based on the three-layer IP network technology, so that the network audio transmission does not depend on the control system and exists independently, and solves the problem of difficulty in laying traditional multi-line audio cables. There is no need for expensive multi-channel analog cables anymore, and low-cost CAT5e and CAT6 cables and 100/1000Mb/s switches are used instead. It also solves the problems that cannot be solved by analog equipment such as long-distance transmission, data backup, and automatic redundancy.

The present invention uses the IEEE1588 precision clock synchronization protocol to perform clock synchronization. Since each audio network interface synchronizes the local clock to the reference clock, the amount of data generated during the packing and unpacking of their data is exactly the same. There will be no loss of audio data due to cache overload.

At the same time, the synchronous clock signal, audio signal and control signal are distributed separately in the same network, and the audio signal and synchronous signal are packaged together and transmitted in the form of UDP/IP. The data packet is transmitted in the network following the absolute time stamp, ensuring that the network Nodes at any position can output the original signal with the same sampling frequency at the same reference time.

The invention adopts a special zero-configuration technology—"plug and play" service discovery technology. Use automatic configuration to automatically find interface devices, identify labels, and distinguish IP addresses, without starting high-level DNS and DHCP services. That is, the configuration of network communication between hosts and between hosts and devices is automatically realized without any manual participation and management, and without the participation of various services. There are mainly two aspects to be completed: (1) IP address automatic allocation, (2) service discovery. When the devices are plugged into the network cable, once connected to the network, they can automatically identify and configure each other on the network, truly plug and play.

The present invention only needs to set the switch on the control terminal such as a computer in advance, and any network endpoint in the local area network can easily consult, monitor and configure the routing of audio signals on the application program interface.

Description of drawings

Fig. 1 is the flow block diagram of embodiment 1 of the present invention;

Fig. 2 is the block diagram of the selection method of the synchronous clock signal of embodiment 1 of the present invention;

Fig. 3 is a structural block diagram of Embodiment 2 of the present invention;

Fig. 4 is a structural block diagram of Embodiment 3 of the present invention.

detailed description

The technical solutions of the present invention will be further described in detail below in conjunction with specific embodiments, but this does not constitute any limitation to the present invention.

Example 1

As shown in Figure 1, a network audio transmission method involves a switch, at least one audio sending device and at least one audio receiving device, the switch, the audio sending device and the audio receiving device are located in the same network segment, the method Specifically:

Step 1: The audio sending device sends the data encapsulated with the IP address, audio signal or control signal to the switch; the audio sending device and the audio receiving device assign an IP address through a zero-configuration network protocol or a DHCP server.

This embodiment adopts a dedicated zero-configuration technology—"plug and play" service discovery technology. Use automatic configuration to automatically find interface devices, identify labels, and distinguish IP addresses, without starting high-level DNS and DHCP services. That is, the configuration of network communication between hosts and between hosts and devices is automatically realized without any manual participation and management, and without the participation of various services. There are mainly two aspects to be completed: (1) IP address automatic allocation, (2) service discovery. When the devices are plugged into the network cable, once connected to the network, they can automatically identify and configure each other on the network, truly plug and play.

More specifically: "Plug and Play" service discovery techniques include the following:

(1) IP address is automatically assigned

Devices connected to the system network will automatically assign configuration information to them, and the configuration parameters will always maintain this network setting. Even if the device is restarted, the network settings will not change

Devices participating in the same link will randomly select an IP address in the address range of 169.254.*

Then send a detection message to detect whether the selected IP address is occupied

Once the IP address of the device is determined, it will continue to send notifications to other devices that the IP address has been occupied.

(2) Service Discovery

(a) When the device or host connected to the system network has no configuration or other configuration management services, the service discovery function can enable the device to automatically discover the services provided on the network,

(b) Support a framework where the client has a user agent process responsible for sending service requests

(c) The server declares the service through the service proxy process

(d) When the service is discovered, the user specifies the characteristic information of the required service, and the user agent sends a service request

(e) If a matching service exists on the network, the user agent will receive a service location reply.

The encapsulation steps of the data described in this embodiment are as shown in Figure 1, the audio signal or control signal is generated in the application/presentation/session layer as a data part, then the UDP header is encapsulated at the transport layer, and the IP header is encapsulated at the network layer, and finally After encapsulating the Ethernet header at the data link layer, data transmission is performed at the physical layer.

The packaged data is shown in Table 1:

Ethernet header/IP header/UDP header Audio signal/control signal

While encapsulating and generating the above-mentioned data, a synchronous clock signal is also encapsulated at the same time.

The synchronous clock signal of the present invention uses the IEEE1588 precision clock synchronization protocol to perform clock synchronization, and the network topology of the IEEE1588 precision clock synchronization protocol consists of a reference clock (Crandmaster Clock), a boundary clock (Boundary Clock) and a local clock (Ordinary CLock). IEEE1588 completes the election of the master clock, which is the reference clock mentioned above, according to the best master clock algorithm (BMC). Each audio device in the network tracks the reference clock, because each audio network interface synchronizes the local clock to the reference clock , so the amount of data generated in the process of packing and unpacking their data is exactly the same, which will not cause audio data loss due to cache overload.

In addition, synchronous clock signals, audio signals and control signals can be sent in the same network, and the audio signals and synchronous signals are packaged together and transmitted in the form of UDP/IP. The data packets are transmitted in the network following the absolute time stamp, ensuring The node can output the original signal with the same sampling frequency at the same reference time.

On each clock of the best master clock algorithm BMC (Best Master Clock Algorithm) independent operation and clock synchronization system (refer to in the system of the present invention here), the data setting comparison algorithm DSC (Data SetComparison Algorithm) in the BMC completes the election work of the master clock.

The DSC algorithm dynamically runs on each clock, and continuously calculates and compares the data set selected by the clock according to the real-time data during the system operation. The data set contains a collection of parameter information such as clock quality, clock level, clock type, and clock offset. The process is shown in Figure 2 below.

According to the results of continuous calculation and comparison, the status of each node and port is dynamically adjusted, and the system will select a more suitable node as the master clock.

The specific calculation method is as follows:

S1: Compare data sets A and B, and judge whether the unique labels of A and B are the same; if they are the same, proceed to S2, and if they are different, proceed to S3; among them, data set A represents the original data set; data set B represents the newly updated Data set; in this step, the unique identification of A and B means that each generated data set in the algorithm is given a unique identification value;

S2: Determine whether the number of forwarded paths of A and B are the same; if they are different, a smaller value is better; In this step, the number of forwarded paths refers to the number of times data sets A and B are forwarded; the larger value and the smaller value are compared by the parameter sequence ID.

S3: Whether the clock levels of A and B are the same, if not, go to S4; if they are the same, judge whether the clock jitter variance of A and B is the same, if not, go to S4, if they are the same, judge whether the identification value of A is smaller than that of B Identification value, if so, enter S4; in this step, the clock level refers to the accuracy level value, whose accuracy is better, the priority level is higher;; clock jitter refers to the fact that the actual clock does not accumulate with time for the ideal clock edge. The leading and sometimes lagging offset is called clock jitter, or jitter for short. The clock jitter can be described quantitatively by jitter frequency and jitter amplitude.

S4: It is better to judge a smaller value.

Step 2: the switch receives the data and sends the data to the audio receiving device corresponding to the IP address;

The switch sends the data to the corresponding audio receiving device according to the IP address encapsulated in the data.

Step 3: The audio receiving device receives the data sent by the switch and decapsulates it to obtain an audio signal or a control signal.

The decapsulation of the data by the audio receiving device can be decapsulated in reverse according to the above encapsulation steps.

The audio signal or control signal in this embodiment is transmitted in the form of data packets, and the audio data is transmitted based on the three-layer IP network technology, so that the network audio transmission does not depend on the control system and exists independently, solving the problem of traditional multi-line audio cable laying Difficult problems, no longer need expensive multi-channel analog cables, switch to low-cost CAT5e and CAT6 cables and 100/1000Mb/s switches. It also solves the problems that cannot be solved by analog equipment such as long-distance transmission, data backup, and automatic redundancy.

This embodiment utilizes the IEEE1588 precision clock synchronization protocol to perform clock synchronization. Since each audio network interface synchronizes the local clock to the reference clock, the amount of data generated during the packaging and unpacking of their data is exactly the same. This prevents audio data from being lost due to buffer overload.

At the same time, the synchronous clock signal, audio signal and control signal are distributed separately in the same network, and the audio signal and synchronous signal are packaged together and transmitted in the form of UDP/IP. The data packet is transmitted in the network following the absolute time stamp, ensuring that the network Nodes at any position can output the original signal with the same sampling frequency at the same reference time.

This embodiment adopts a dedicated zero-configuration technology—"plug and play" service discovery technology. Use automatic configuration to automatically find interface devices, identify labels, and distinguish IP addresses, without starting high-level DNS and DHCP services. That is, the configuration of network communication between hosts and between hosts and devices is automatically realized without any manual participation and management, and without the participation of various services. There are mainly two aspects to be completed: (1) IP address automatic allocation, (2) service discovery. When the devices are plugged into the network cable, once connected to the network, they can automatically identify and configure each other on the network, truly plug and play.

In this embodiment, it is only necessary to pre-set the switch on a control terminal such as a computer, and any network endpoint in the local area network can easily view, monitor, and configure audio signal routing on the application program interface.

Example 2

As shown in Figure 3, a network audio transmission system includes a switch 1, one less audio sending device 2, and at least one audio receiving device 3, and the switch 1, audio sending device 2 and audio receiving device 3 are located on the same network segment Inside;

The audio sending device 2 is used to encapsulate the data containing IP address, audio signal or control signal, and send the data to the switch 1; in order to further improve the synchronization of the data, the data is also packaged together with the synchronous clock signal and sent to the switch 1;

The switch 1 is used to receive the data and send the data and the synchronous clock signal to the audio receiving device 3 corresponding to the IP address;

The audio receiving device 3 is used for receiving data and synchronous clock signals sent by the switch and decapsulating them to obtain audio signals or control signals. The audio receiving device 3 outputs audio signals or control signals at the same reference time according to the synchronous clock signal. In this way, data transmission and synchronous playback on the network level are realized.

In this embodiment, the switch 1 includes a data receiving and sending unit and a configuration unit for automatically configuring an interface device, an identification label, and distinguishing an IP address for an access device and pairing with the access device. The control signal It includes the interface device, identification label and distinguishing IP address for receiving the data packet, and the interface device, identification label and distinguishing IP address for sending the data packet.

The audio data in this embodiment is transmitted in the form of data packets (the data packet format is shown in Figure 1-2-2), and the audio data is transmitted based on the three-layer IP network technology, so that the network audio transmission does not depend on the control system and exists independently , to solve the problem of difficult laying of traditional multi-line audio cables, no longer need expensive multi-channel analog cables, and use low-cost CAT5e and CAT6 cables and 100/1000Mb/s switches. It also solves the problems that cannot be solved by analog equipment such as long-distance transmission, data backup, and automatic redundancy.

This embodiment utilizes the IEEE1588 precision clock synchronization protocol to perform clock synchronization. Since each audio network interface synchronizes the local clock to the reference clock, the amount of data generated during the packaging and unpacking of their data is exactly the same. This prevents audio data from being lost due to buffer overload.

At the same time, the synchronous clock signal, audio signal and control signal are distributed separately in the same network, and the audio signal and synchronous signal are packaged together and transmitted in the form of UDP/IP. The data packet is transmitted in the network following the absolute time stamp, ensuring that the network Nodes at any position can output the original signal with the same sampling frequency at the same reference time.

This embodiment adopts a dedicated zero-configuration technology—"plug and play" service discovery technology. Use automatic configuration to automatically find interface devices, identify labels, and distinguish IP addresses, without starting high-level DNS and DHCP services. That is, the configuration of network communication between hosts and between hosts and devices is automatically realized without any manual participation and management, and without the participation of various services. There are mainly two aspects to be completed: (1) IP address automatic allocation, (2) service discovery. When the devices are plugged into the network cable, once connected to the network, they can automatically identify and configure each other on the network, truly plug and play.

In this embodiment, it is only necessary to pre-set the switch on a control terminal such as a computer, and any network endpoint in the local area network can easily view, monitor, and configure audio signal routing on the application program interface.

Example 3

In the following, this embodiment uses specific examples to explain the method of the present invention.

As shown in FIG. 4 , a microphone 11 , a router 12 , a DSP processor 13 , a mixer 14 , a sound system 15 , and a PC 16 are taken as examples.

(a) Embedding converter modules (including Ethernet network ports) in devices other than routers or switches 12

(b) Build a network audio system as shown in Figure 3:

(b1) The transmission line between each device is a twisted pair of cat5 or above

(b2) Each audio device and PC are connected to the network port of the router through a network cable of cat5 or above

(b3) Each device will obtain an IP address in the range of 169.254.* according to the zero-configuration protocol,

(b4) The control program of the PC has a service discovery function to discover the information of each device in the network system (including name, IP address, number of audio channels, etc.)

(c) now the control program of the PC 16 can set the audio routing we want, for example, the channel-1 of the microphone 11 can be set as the sending end, and the channel-1 and channel-2 of the mixer can be used as the receiving end,

(d) the channel-1 and channel-2 of the mixing console 14 are used as the sending end, and the channel-1 and channel-2 of the DSP processor 13 are used as the receiving end. After the audio signal is processed by the mixing console 14, it will be sent to DSP processor 13;

(e) Channel-1 and channel-2 of the DSP processor 13 are used as sending ends, and channel-1 and channel-2 of the audio are used as receiving ends. After the DSP processor 13 processes the audio signal, it will be sent to the audio signal 15 channel-1 and channel-2 output audio signals as left and right channels.

During the above c-e data transmission process, the audio signal will be packaged with the IP address of the device to be transmitted, and will be packaged with the synchronous clock signal at the same time, and sent to the corresponding device through the switch.

When a new device needs to be added to the system, the device needs to be embedded or connected to our converter module (including Ethernet network port), and then connected to the switch or router in the audio network through a twisted pair of cat5 and above 12. For example, if you add a mobile device, the mobile device can be used as the sender, connected to the converter module through the 3.5 audio cable (in the audio network, its channel-1 and channel-2 will be used as the sender), and the converter module will pass through the cat5 class And above the twisted pair is connected to the audio network, so that the addition of new equipment is realized.

The above are only preferred embodiments of the present invention, and any modifications, equivalent replacements and improvements made within the spirit and scope of the present invention shall be included within the protection scope of the present invention.

Claims (7)

1. A network audio transmission method, involving a switch, at least one audio sending device and at least one audio receiving device, wherein the switch, the audio sending device and the audio receiving device are located in the same network segment, wherein the method Specifically: Step 1: The audio sending device sends the data encapsulated with IP address, audio signal or control signal to the switch; Step 2: the switch receives the data and sends the data to the audio receiving device corresponding to the IP address; Step 3: The audio receiving device receives the data sent by the switch and decapsulates it to obtain an audio signal or a control signal. 2. The network audio transmission method according to claim 1, wherein in step 1, the audio sending device and the audio receiving device assign IP addresses through a zero-configuration network protocol or a DHCP server. 3. The network audio transmission method according to claim 2, characterized in that, in step 1, the audio sending device encapsulates the audio signal or control signal at the transport layer with the UDP header, and at the network layer encapsulates the IP address, encapsulates the Ethernet header at the data link layer, and sends it to the physical layer; After the audio receiving device receives the data sent by the audio sending device at the physical layer, it performs corresponding decapsulation operations at the data link layer, network layer, and transport layer to obtain audio signals or control signals. 4. The network audio transmission method according to claim 1, further comprising a synchronous clock signal, the synchronous clock signal is packaged synchronously with the data, and the audio receiving device outputs at the same reference time according to the synchronous clock signal audio signal or control signal. 5. The network audio transmission method according to claim 1, wherein the audio sending device includes at least one of a microphone, a digital music storage and playback unit, and a DSP digital processor; the audio receiving device includes a stereo , DSP digital processor, and at least one of digital music storage and playback units. 6. A network audio transmission system, comprising a switch, one less audio sending device, and at least one audio receiving device, said switch, audio sending device and audio receiving device being located in the same network segment, characterized in that: The audio sending device is used to encapsulate data including IP address, audio signal or control signal, and send the data to the switch; The switch is used to receive the data and send the data to the audio receiving device corresponding to the IP address; The audio receiving device is used to receive the data sent by the switch and decapsulate it to obtain an audio signal or a control signal. 7. The network audio transmission system according to claim 6, characterized in that, the audio sending device is also used to package the synchronous clock signal and the data to the switch; The audio receiving device is used for outputting audio signals or control signals at the same reference time according to the synchronous clock signal.