KR20040042001A - Video transmitter for protecting DVI outputs and method thereof - Google Patents

Abstract

PURPOSE: An apparatus and a method for encoding and transmitting video data for copy guard are provided to display a specific help message even in an unauthenticated device when encoded data is transmitted using a digital video interface high-bandwidth digital content protection system. CONSTITUTION: An apparatus for encoding and transmitting video data includes a controller(250), a video signal input unit(240), a storage unit(230), an encoder(210), and a transmitter(220). The controller judges whether an external display device(300) is authenticated and controls components of the apparatus on the basis of the judged result. The video signal input unit receives video data from an external device to output the video data to the encoder. The storage unit stores information corresponding to the video data. The encoder encodes the video data according to whether the external display device is authenticated or not. The transmitter transmits the encoded video data.

Description

Device and method for encrypting video data for copy protection {Video transmitter for protecting DVI outputs and method

The present invention relates to an apparatus and method for encrypting transmission of image data for copy protection, and more particularly, to an apparatus and method for displaying help information when sending an encrypted image to an unauthorized digital video receiver.

Recently, LCD monitors have been introduced to the public, and have been introduced to differentiate quality from existing analog products, and there are LCD monitors employing a digital video interface (DVI). In the case of the existing analog interface LCD monitor, the signal loss and interference caused noise, which caused the focus to deteriorate with time, and the DAC (DIGITAL TO ANALOG CONVERTER) and the ADC (ANALOG TO DIGITAL) were applied to the graphics board and the monitor, respectively. Because it needs to have a built-in CONVERTER), it caused a cost increase.

Another problem is that the analog VGA standard has a severe quality deviation of the output signal according to the manufacturer and each graphic board.

To cope with these problems, the digital interface called DVI came out to improve image quality and reduce cost. In other words, DVI means that the interface between the monitor and the graphics card is digital. This is because in case of LCD monitor, the interface of the panel itself is digital, and if the analog signal is received from the graphics card and converted to digital again, data loss occurs in two conversion processes. In addition, in the case of digital LCD monitors, there is no need to install an analog to digital converter (ADC). Therefore, the adoption of DVI, which has excellent image quality and lowers costs, is a natural phenomenon.

In general, DVI is a VGA interface, a specification created by the Digital Display Working Group (hereinafter referred to as "DDWG") to accommodate analog and digital monitors in one connector. The DVI standard created by DDWG supports high-speed data transfer of up to 9.9 Gbps over dual links and up to 2.5 GHz for analog, while the transmission method of video signals is similar to Transition Minimized Differential Scaling such as P & D and DFP. The digital transmission protocol called TMDS "is known to be highly favored by the industry because DFP can be converted to DVI using only the conversion mode. Here, the TMDS (Transmission Minimized Differential Signaling) signal conversion method is a technique for receiving and demodulating the received data when the transmitting side modulates parallel data into high speed serial data.

Therefore, DVI support requires a signal conversion chipset called TMDS Transmitter and TMDS Receiver. This method was developed by Silicon Image of the United States and became the world standard. Transmitter is attached to the graphic card and receiver is attached to the monitor to transmit digital data from the graphic card to the monitor.

The purpose of TMDS Link is to send digital data from the PC farther (with longer cable lengths) without loss of signal, and convert it to carry higher bandwidth signals. TMDS Link is divided into single link and dual link according to the data rate. Dual link has twice the number of channels that can transmit data compared to single link. In monitors, the data transfer rate is closely related to the amount of information that can be displayed on the screen, which has a direct impact on the maximum resolution.

There are three different configurations of these DVI types: DVI-A is designed for analog signals, DVI-D for digital signals, and DVI-I for analog and digital signals.

1 illustrates a digital image display device that receives a digital signal from an external signal source through a DVI-D type connector or a DVI-I type connector. As shown in FIG. 1, the received digital signal is first decoded by the digital image processor 20 into a digital image signal, a horizontal synchronization signal, and a vertical synchronization signal.

That is, the digital image processing unit 20 is generally implemented as a TMDS receiver. The digital image processor 20 receives a digital signal coded by a TMDS conversion method from an external signal source, and horizontally inputs the input digital signal to a digital video signal by a TMDS signal conversion method. Decoded into a synchronization signal and a vertical synchronization signal. The digital image signal decoded from the digital image processor 20 is signal-converted to a resolution set by the scaler 50 and then displayed on the panel by the panel driver 60.

On the other hand, when receiving an analog signal from an external signal source through a DVI-I type connector, the analog image signal is first converted into a digital image signal by the analog image processor 10.

That is, the analog image processing unit 10 is typically implemented as an analog digital converter (ADC) and a phase lock loop (PLL), and receives an analog video signal from an external signal source and converts the input analog video signal into a digital video signal. Convert.

The digital image signal converted from the analog image processor 10 is converted into a signal according to the resolution set by the scaler 50 and then displayed on the panel by the panel driver 60.

In this case, the controller 80 of the digital image display device according to the present invention determines whether the connected connector is a DVI-D type or a DVI-I type, sets the switching mode according to the determination result, and switches the switching unit according to the set switching mode. 30 and 40 are controlled to selectively display analog video signals and digital video signals on the screen.

Reference numeral 90 denotes an OSD IC displaying characters, and 70 denotes a power supply unit.

On the other hand, as the technical standard that can greatly enhance the protection of copyright of digital contents, which has been the biggest obstacle ahead of the launch of high-definition digital TV broadcasting in the United States in 2003, High Definition Multimedia Interface (HDMI) We released version 0.9. This specification combines high-definition video and multichannel audio into a single digital interface with 5Gb bandwidth per second, integrated audio using packetized data transmission technology, a 15mm 19-pin HDMI interface for consumer electronics, and high-bandwidth digital content protection. (HDCP) integration, etc.

HDMI classifies and distributes digital content between set-top boxes and TV receivers that control cable and satellite TV programs that send out hundreds of channels, including unlimited copying, one-time copying, and non-copying. As a result, it is possible for consumers (viewers) to charge a royalty fee for recording and playing content.

In order to protect the DVI signals of various contents, a High-bandwidth Digital Content Protection System (hereinafter referred to as "HDCP") is used between the DVI video transmitter and the DVI video receiver. I use it. That is, HDCP uses an encryption protocol to protect video transmission in a DVI video transmitter and transmits authentication in a DVI video receiver so that the video is displayed only in the authenticated receiver.

That is, as shown in FIG. 2, the transmitter 100 supporting the DVI-HDCP transmits by encrypting the contents which are responsible for protection when transmitting the video data to the unauthenticated device (200). Since 300 is unable to receive the encrypted screen 310 and decrypt it, the screen 300 is not normally viewed. The screen is processed and displayed normally only on the receiving device which has been recognized.

Since the scrambled encrypted screen cannot be viewed by the user at all, users who use a lot of remote controllers are embarrassed because they cannot adjust the screen. In other words, even if the user wants to change the screen with the remote control using an additional device such as an OSD, the user cannot be comfortable because the next operation cannot be performed because of the encrypted screen.

That is, since no message can be displayed on the screen through the screen of the unauthenticated device, it is impossible to provide an additional description of the encrypted screen using the OSD for the convenience of the user.

In order to solve the above problems, the present invention is to provide an apparatus and method for transmitting and transmitting video data that can display a specific help message even when an encrypted device is transmitted using DVI-HDCP.

1 is a block diagram of a conventional digital video display device receiving a digital signal from an external signal source;

2 is a schematic diagram showing a screen display state of an uncertified device;

3 is a schematic diagram showing a screen display state of an uncertified device according to the present invention;

4 is a flowchart illustrating a screen display state in an uncertified device of the present invention.

<Description of the symbols for the main parts of the drawings>

210: encryption unit 220: transmission unit

230: storage unit 240: video signal input unit

250: control unit 300: external display device

In order to achieve the above object, the encryption transmission apparatus of the image data for copy protection according to the present invention,

A control unit for determining whether the external display device connected to the encryption device is authenticated, and controlling the operation of each component constituting the encryption device based on the determination result, and a storage unit for storing additional information corresponding to the image data. When the control unit determines that the authentication result is not verified, the controller reads the additional information from the storage unit and inserts the additional information into the image data according to a control signal of the controller to encrypt the image data. It includes an encryption unit for encrypting the image data so that the additional information is displayed in the state that the data is not decrypted and a transmission unit for transmitting the encrypted image data.

The storage unit may store at least one or more information from among information on content corresponding to the image data, subscription information, and information on an authentication procedure.

The encryption unit inserts the additional information into the image data so that the additional information is displayed in one region of the screen region where the image data is to be displayed, and does not encrypt the image data corresponding to the region where the additional information is displayed. desirable.

The encryption unit may encrypt and de-encrypt the video data into which the additional information is inserted at a predetermined time period.

In order to achieve the above another object, an encrypted transmission method of a video signal for copy protection of the present invention is an encryption transmission apparatus for video data for copy protection.

When the request for transmission of the image data is input from the outside, the step of determining whether the request is authenticated or not and if the determination result of the authentication result is not authenticated, inserts additional information into the image data and encrypts the encrypted data. Encrypting the image data so that the additional information is displayed even if the encrypted image data is not decrypted, and transmitting the encrypted image data.

The encrypting may include inserting the additional information into the image data so that the additional information is displayed in one region of the screen region where the image data is to be displayed, and encrypting the image data corresponding to the region where the additional information is displayed. It is desirable not to.

More preferably, the step of encrypting does not insert the additional information into the video data when the authentication result determines whether the authentication result is determined.

Hereinafter, with reference to the accompanying drawings a preferred embodiment of the present invention will be described in detail.

3 is a schematic block diagram of a screen display method and a transmission apparatus in an uncertified receiver according to the present invention. As shown, the encryption apparatus determines whether the external display apparatus 300 is authenticated, and controls the operation of each component constituting the encryption apparatus based on the determination result and the image data from the outside. The external display device 300 under the control of the image signal input unit 240 for receiving the output signal to the encryption unit 210 and the storage unit 230 and the control unit 250 storing the additional information corresponding to the image data It consists of an encryption unit 210 for encrypting the image data according to the authentication of the transmission unit 220 for transmitting the encrypted image data.

The encryption unit 210 encrypts the image data by reading additional information stored in the storage unit 230 and inserting the additional information stored in the storage unit 230 when it is determined that the determination result of the control unit 250 is not authenticated. It is preferable to encrypt the image data so that the additional information is displayed in a state where the encrypted image data is not decrypted.

In addition, the encryption unit 210 inserts additional information into the image data so that the additional information is displayed in one area 320 of the screen area 310 where the image data is to be displayed, and corresponds to an area where the additional information is displayed. It is more preferable not to encrypt the video data.

When the encryption unit 210 determines that the authentication result of the control unit 250 determines that the authentication result is authenticated, the encryption unit 210 does not insert the additional information into the image data based on the control signal of the control unit 250. In addition, the controller 250 preferably encrypts and de-encrypts the video data into which the additional information is inserted at a predetermined time period.

Hereinafter, a method of encrypting and transmitting image data for copy protection according to the present invention will be described with reference to FIG. 4.

When a request for transmitting the image data is input from the external display device 300 (step 400), the controller 250 determines whether the request is authenticated (step 410).

If it is determined in step 410 that the authentication result is not authenticated, the controller 250 controls the encryption unit 210 to encrypt the image data in order to protect the image data. At this time, the encryption unit 210 encrypts the image data while inserting the additional information stored in the storage unit 210 into the image data to encrypt the image data. Preferably, the image data is encrypted so that the additional information is displayed even when the encrypted image data is not decrypted (step 420).

In addition, when it is determined that the authentication result determines whether the authentication is performed in step 410, the image data is de-encrypted and transmitted to the transmitter 220 without inserting the additional information into the image data (step 430).

The transmitter 220 receives the encrypted image data displaying the additional information from the encryption unit 210 and transmits the encrypted image data to the external display device 300 (step 440).

In addition, in step 420, the additional information is inserted into the image data so that the additional information is displayed in one area 320 of the screen area 310 where the image data is to be displayed, and corresponds to an area where the additional information is displayed. It is preferable not to encrypt the image data so that it can be received and read even by a receiving apparatus which is not equipped with a decoder.

As described above, according to the apparatus and method for encrypting and transmitting image data for copy protection according to the present invention, it is convenient because the help information can be displayed on the encrypted screen using the OSD even through the screen of an unauthenticated device. .

While the invention has been described in detail only with respect to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the spirit of the invention, and such modifications and variations belong to the appended claims.

Claims (8)

In the encryption device of digital image data for copy protection, A control unit which determines whether the external display device connected to the encryption device is authenticated, and controls an operation of each component constituting the encryption device based on the determination result; A storage unit which stores additional information corresponding to the image data; The control unit reads the additional information from the storage unit and inserts the additional information into the image data according to a control signal of the controller to encrypt the image data. An encryption unit for encrypting the image data so that the additional information is displayed in a state where the data is not decrypted; And And a transmission unit for transmitting the encrypted image data. The method of claim 1, wherein the storage unit And at least one of information on contents corresponding to the video data, subscription information, and information on an authentication procedure. The method of claim 1, wherein the encryption unit The additional information is inserted into the image data so that the additional information is displayed in one region of the screen region where the image data is to be displayed, and the image data corresponding to the region where the additional information is displayed is not encrypted. Encrypted transmission device of video signal for prevention. The method of claim 1, wherein the encryption unit And encrypting and deciphering the video data into which the additional information is inserted at a predetermined time period. The method of claim 1, wherein the encryption unit And the identification result of the authentication of the controller determines that the additional information is not inserted into the image data based on a control signal of the controller. In the encryption transmission apparatus of the image data for copy protection, Determining whether the request is authenticated when an external image transmission request is input; And encrypting the insertion by inserting additional information into the video data and determining that the additional information is displayed even when the encrypted video data is not decrypted. ; And Transmitting the encrypted image data; and encrypting and transmitting the image data for copy protection. 7. The method of claim 6, wherein the encrypting step The additional information is inserted into the image data so that the additional information is displayed in one region of the screen region where the image data is to be displayed, and the image data corresponding to the region where the additional information is displayed is not encrypted. Encrypted transmission method of video signal for prevention. 7. The method of claim 6, wherein the encrypting step The result of the determination of whether or not the authentication is performed. When the authentication is performed, the additional information is not inserted into the video data.