KR20130085530A - Apparatus for video transmission - Google Patents

Abstract

PURPOSE: An image transmission device is provided to enable a user to use an application requiring real-time images like a game in a virtual environment or a central management-type personal computer (PC) rack system. CONSTITUTION: An image transmission device (120) is composed of a network interface card (120a) and image transmission hardware (120b). The network interface card is composed of a host interface (121), media access control (MAC) (122), a packet transmission engine (123), and a packet reception engine (124). The host interface takes charge of interfacing with a host processor. The MAC performs an external interface function with a network. The packet transmission engine processes data received from the host interface and delivers to the MAC in order to transmit the data to the network. The packet reception engine receives data from the network through the MAC and delivers to the host interface. The image transmission hardware includes an image signal processing part (125), a user datagram protocol (UDP) processing engine (126), and a multiplexer (MUX) (127). The image signal processing part receives an output signal of a video card and converts the corresponding signal into image file data. The image signal processing part converts an RGB or a digital visual interface (DVI) signal into image file data and delivers to the UDP processing engine. [Reference numerals] (121) Host interface; (123) Packet transmission engine; (124) Packet reception engine; (125) Image signal processing part; (126) UDP processing engine; (AA) Video card output signal

Description

Apparatus for video transmission

The present invention relates to an image transmission device. More specifically, the present invention relates to an image transmission apparatus capable of transmitting a high quality image over a network with minimal delay time.

Remote transmission of video signals is required for server-based computing and remote use of personal computers (PCs). To this end, a system that hooks an API (Application Programming Interface) at a predetermined position of a graphic processing stack of an operating system (OS) and transmits it to a client of a remote user is used. However, since the client side requires a certain level of CPU (Central Preocessing Unit) and a graphics card to display this image, it must have a computer-like system like a general PC or thin client.

Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and Internet Protocol (IP) are protocols for transmitting data over a network, and are typically handled by the CPU. As the network bandwidth grew, such protocol processing began to weigh on the CPU.

As the computing power of PCs improves, they often fail to use all the available computing power. In order to solve such a situation, many virtualization solutions using a single PC are being developed. In addition, a centrally managed PC rack system is also used to save and manage power by bringing PCs together in one place, like a server, and providing only a monitor, keyboard and mouse to users. In this case, the transmission of the image from the PC to the monitor that the real user sees is essential. In addition, there is a need for development of a technology for solving the problem of delay time occurring in image transmission.

SUMMARY OF THE INVENTION An object of the present invention is to provide a technique for transmitting a high quality image having a low delay time using a high bandwidth in a relatively short LAN (LAN) environment. That is, an object of the present invention is to enable the use of applications that require real-time video, such as games even in a virtualized environment or a centrally managed PC rack system.

In addition, the present invention aims to facilitate switching between users by using a MAC address and IP by using a network packet form, unlike a simple cable extension.

In addition, an object of the present invention is to make it easy to implement in hardware using a UDP protocol that is relatively simple to process compared to TCP.

According to an aspect of the present invention, there is provided an image transmission apparatus comprising: an image signal processing unit receiving a signal output from a video card and converting the signal into image file data; And a UDP processing engine for receiving the image file data and converting the image file data into an Ethernet packet form that can be transmitted through a UDP (User Datagram Protocol) protocol. That is, the present invention can packetize and transmit an output signal of a video card.

At this time, the present invention can use the Ethernet switch for switching the user by using the MAC (Media Access Control) address and IP at packetization.

In this case, the present invention allows the PC and the thin client system to receive an image by using the UDP / IP protocol during packetization.

In this case, the present invention may compress or encrypt the packetized image file data and transmit the same.

In this case, the present invention may include an ARP processing function for searching for a MAC address using IP.

At this time, the present invention can periodically check whether the user's device is connected using the ARP.

At this time, the present invention can determine whether the user's device is operating by analyzing the received ICMP.

In addition, the image receiving apparatus according to the present invention is a device capable of receiving and outputting image data transmitted over a network to a monitor, and may select and process a header type for dedicated hardware and a UDP / IP header type for compatibility. .

At this time, the present invention has an IP, and can process an ARP response to inform the MAC address of the device.

The present invention may further include a function of releasing or decrypting the received image data when it is compressed or encrypted.

According to the invention, the output of the video card is transmitted to the network via a UDP processing engine.

Accordingly, the present invention can provide a technique for transmitting a high quality image having a low delay time using a high bandwidth in a relatively short LAN (LAN) environment. Through this, the present invention enables the use of applications requiring real-time video such as games even in a virtualized environment or a centrally managed PC rack system.

In addition, the present invention can facilitate the switching between users by using the MAC address and IP by using a network packet form, unlike a simple cable extension.

In addition, the present invention can be easily implemented in hardware using the UDP protocol, which is relatively simple to process compared to TCP.

1 illustrates a network environment to which an image transmission device according to an embodiment of the present invention is applied.
2 is a block diagram illustrating a configuration of an image transmission apparatus according to an embodiment of the present invention.
3 illustrates an example of a network packet form used for image transmission according to the present invention.
4 is a block diagram illustrating a configuration of an image receiving-only card according to an embodiment of the present invention.
5 is a diagram illustrating a network environment to which an image transmission device according to another embodiment of the present invention is applied.
6 is a block diagram illustrating a configuration of an image transmission apparatus according to another embodiment of the present invention.
7 shows another example of a network packet form used for image transmission according to the present invention.

The present invention will now be described in detail with reference to the accompanying drawings. Hereinafter, a repeated description, a known function that may obscure the gist of the present invention, and a detailed description of the configuration will be omitted. Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art. Accordingly, the shapes and sizes of the elements in the drawings and the like can be exaggerated for clarity.

Hereinafter, the configuration and operation of an image transmission apparatus according to an embodiment of the present invention will be described.

1 illustrates a network environment to which an image transmission device according to an embodiment of the present invention is applied. 2 is a block diagram illustrating a configuration of an image transmission apparatus according to an embodiment of the present invention. 3 illustrates an example of a network packet form used for image transmission according to the present invention. 4 is a block diagram illustrating a configuration of an image receiving-only card according to an embodiment of the present invention.

Referring to FIG. 1, the image transmission device 120 according to an embodiment of the present invention may be configured by adding a function for image transmission to a network interface card. The image transmission apparatus 120 is mounted on the server 100, and the image transmission apparatus 120 receives and transmits an image signal output from the video card 110. At this time, the server 100 may be configured as a PC. That is, the image transmission device 120 also functions as a network card of the server 100 in addition to image transmission. The Ethernet switch 20 also participates in transmission and reception of network packets through connection with the external network 50 as well as transmission of image data packets. In this case, the Ethernet switch 20 may be connected to the thin client 30, the monitor 40, and the image receiving dedicated card 200, which are targets of receiving image data.

The user may connect and use the thin client 30, or may connect and use the image receiving dedicated card 200 and the monitor 40. At this time, the thin client may be a PC or a netbook.

Referring to FIG. 2, the image transmission device 120 may be configured with a network interface card 120a and image transmission function hardware 120b.

The network interface card 120a includes a host interface 121, a MAC 122, a packet transmission engine 123, and a packet reception engine 124.

The host interface 121 is responsible for the interface with the host processor. The MAC 122 performs a connection function with the network, that is, an external interface function. The packet transmission engine 123 processes the data obtained from the host interface 121 and transmits the data to the MAC 122 for transmission to the network. The packet receiving engine 124 receives the data received from the network through the MAC 122 and delivers the received data to the host interface 121. At this time, the packet transmission engine 123 may add the image transmission function hardware 120b to the passage for transmitting data to the MAC 122, and may directly transmit the image to the network.

The video transmission function hardware 120b includes a video signal processor 125, a UDP processing engine 126, and a MUX 127.

The video signal processor 125 receives an output signal from the video card and converts the signal into video file data. The image signal processing unit 125 converts the RGB or DVI signal into image file data and transmits the converted image file data to the UDP processing engine 126. At this time, the image can be compressed or encrypted if necessary.

The UDP processing engine 126 receives the image file data from the image signal processor 125 and converts the image file data into an Ethernet packet form that can be transmitted through the UDP protocol. At this time, the UDP processing engine 126 divides the image file data into an acceptable size in the network, generates MAC, IP, UDP headers, and attaches the divided data. It also adds the header fields needed for passing graphical data. At this time, necessary information (for example, counterpart IP information, etc.) is recorded by the host interface 121 in the register of the UDP processing engine 126. The packet generated as described above is transferred to the MAC layer 122 and transmitted to the network. At this time, the priority in the MUX 122 is to have a packet transmitted from the UDP processing engine 126 so that there is no delay of the video.

Referring to FIG. 1 and FIG. 2, in order for the server 100 to transmit an image to the thin client 30 or an image receiving dedicated card 200, the MAC address of the other party is known using the network interface card 120a. Serve This can be found using ARP Query. The MAC address thus found is recorded in the UDP processing engine 126, and the UDP processing engine 126 transmits the data received from the image signal processing unit 125.

Referring to FIG. 3, a form of a packet generated by the UDP processing engine 126 is illustrated. In order to use Ethernet network, MAC Header (1) and MAC Trailer (9) are essential. The MAC Trailer 9 may be generated in the MAC 122. The MAC address used for the MAC Header 1 is notified by the host processor through the host interface 121.

IP Header (2) and UDP Header (3) are also necessary for maintaining compatibility with general network processing methods. Similarly, information such as an IP address or a port number is notified by the host processor through the host interface 121, and fields such as checksums of the UDP headers are directly generated by the UDP processing engine 126.

The Packet Counter (4) field and the Frame Counter (5) field are information for determining whether data has been normally received at the receiving side. Frame means one video and Packet shows the order when one frame is divided into several packets and transmitted. That is, if two video frames are divided into two and three packets, respectively, the frame counter (5) and the packet counter (4) are (0,0), (0,1), (1,0), It is recorded in the order of (1, 1), (1, 2). The EOF (7) field is a field for informing that it is the last packet of each frame. In other words, the packet corresponding to (0, 1) and (1, 2) is marked as 1 and transmitted. The ERR (6) field is meaningful only when the EOF (7) field is 1 and indicates that the corresponding frame is abnormal. The thin client 30 or the image receiving dedicated card 200 removes the troubled frame when the Packet Counter 4 or Frame Counter 5 is not sequential, and when the ERR (6) field is checked. Spray onto monitor properly.

The data received from the video signal processor 125 is inserted into the video data 8 and transmitted. Generally, the part called UDP payload is the Received Data (10) part including some header fields in this Video Data (8), so the checksum included in the UDP header includes all the Received Data (10) parts.

The reason why a packet may be lost in the video transmission, such as UDP, is because it is easy to implement in pure hardware as described above, but in the case of real-time video with low latency, a procedure such as retransmission upon packet loss Is meaningless.

Referring to Figure 4, the image receiving dedicated card 200 according to an embodiment of the present invention is MAC 210, DEMUX 220, ARP processing engine 230, UDP processing engine 240 and the image signal processing unit ( 250).

The dedicated image receiving card 200 does not have a processor. The packet received through the MAC 201 is divided into an ARP packet and a UDP packet in the DEMUX 202, and delivered to the ARP processing engine 230 and the UDP processing engine 240, respectively, and all other packets are discarded.

The ARP processing engine 230 plays a role in responding to the ARP request packet when it is received.

The UDP processing engine 240 extracts the received video data packet and informs the video signal processor 250. All but discarded UDP packets received on pre-defined ports are discarded. The Packet Counter (4), Frame Counter (5), ERR (6), and EOF (7) fields of FIG. 3 check whether there are any problems with the frame, and the Video Data processing unit 250 uses the Video Data 8 section. Only pass. In addition, a problem or missing frame will be notified every time using an error signal.

The image signal processor 250 performs a function opposite to that of the image signal processor 125 of FIG. 2. The video data received from the UDP processing engine 240 is converted into an RGB or DVI signal and transferred to the monitor 40. At this time, the image signal processing unit 250 may decompress the compressed image and decrypt the encrypted data if necessary.

The dedicated video receiving card 200 is hardware specialized for the application, so there is no reason to use the IP / UDP protocol. For example, if there is no router between the video transmission network card 120 and the video reception dedicated card 200, the packet can be transmitted simply by using only a MAC address. Therefore, the packet form of FIG. 3 can also be modified and used as shown in FIG. This method can reduce the size of the protocol header to effectively use the bandwidth. The additional use of Jumbo Frames can make the effect even greater.

That is, if there is no router in the image data transmission network, and the receiving user uses the image receiving dedicated card 200, the IP and UDP headers are removed and only the CRC 11 field for error checking can be added and transmitted. Of course, the UDP processing engine 240 of the receiving card is also configured to process packets of the corresponding format through the setting.

Hereinafter, the configuration and operation of an image transmission device according to another embodiment of the present invention will be described.

5 is a diagram illustrating a network environment to which an image transmission device according to another embodiment of the present invention is applied. 6 is a block diagram illustrating a configuration of an image transmission apparatus according to another embodiment of the present invention. 7 shows another example of a network packet form used for image transmission according to the present invention.

5 and 6, in the image transmitting apparatus 320 according to another embodiment of the present invention, the network function is separated from the image transmitting apparatus 120 according to FIGS. 1 and 2, so that the network card 330 is separately provided. There is a difference in configuration. Therefore, hereinafter, the image transmission device 320 according to another embodiment of the present invention will be described based on the above differences, and a description of the same configuration will be omitted.

The image transmission apparatus 320 according to another embodiment of the present invention may have more margin in the image transmission bandwidth and the network bandwidth by using a different network than the network card 330. The user may connect and use the thin client 30, or may connect and use the image receiving dedicated card 200 and the monitor 40. At this time, the image transmission device 320 receives the image signal output from the video card 310 and transmits the image, but does not have a function as a network interface card of the server 300. In this case, the network card 330 such as the LOM performs a function of connection with the external network 50 as a network interface card. The Ethernet switch 20 'is not necessary when the user is connected 1: 1 with the user, and is used when the user's switching is required.

The image transmission device 320 according to another embodiment of the present invention does not have a function of a network interface card. Therefore, the packet data is not transmitted through the host interface 321. The host interface 321 is a UDP processing engine 323 and an Address Resolution Protocol (ARP) / Internet Control Message Protocol (ICMP) processing engine 325 to give only data and commands necessary for setting. The video signal processor 324 and the UDP processing engine 323 perform the same functions as the video signal processor 125 and the UDP processing engine 126 of FIG. 2. However, there is a difference that the subject that delivers the other party's MAC address is the ARP / ICMP processing engine 325, not the host processor.

The ARP / ICMP processing engine 505 performs the following functions. First, the host processor 321 receives a command to find the MAC address of the other party's IP. To this end, it generates an ARP packet, receives the ARP response packet, extracts the other party's MAC address, and informs it to the UDP processing engine 323. Second, send ARP packet periodically to the other party's IP to check if connection with the other party is maintained. Finally, the ICMP packet is processed. Even if the physical connection is continued, communication through the port may not be possible. In this case, the counterpart system sends a message such as destination unreachable using ICMP, and the ARP / ICMP processing engine 505 receives and processes it. If the connection is lost or communication using the corresponding port is not possible, the host interface 321 is notified. All other received packets are discarded.

As described above, the image transmission apparatus according to the present invention is not limited to the configuration and method of the embodiments described as described above, but the embodiments are all or part of each embodiment so that various modifications can be made. May be optionally combined.

100; server
110; Video card 120; Video transmission device
120a; Network interface card 120b; Video transmission hardware
121; Host interface 122; MAC
123; Packet transmission engine 124; Packet Receive Engine
125; An image signal processor 126; UDP processing engine
200; Dedicated video reception card 210; MAC
220; DEMUX 230; ARP Processing Engine
240; UDP processing engine 250; Image signal processor
300; server
310; Video card 320; Video transmission device
321; Host interface 322; MAC
323; UDP processing engine 324; Image signal processor
325; ARP / ICMP treatment engine 326; MUX
330; Network card
20, 20 '; Ethernet switch 30; Thin client
40; Monitor 50; External network

Claims (1)

A video signal processor which receives a signal output from a video card and converts the signal into image file data; And
And a UDP processing engine for receiving the image file data and converting the image file data into an Ethernet packet that can be transmitted through a UDP protocol.

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