KR100196715B1 - Subscriber home automation device with copy protection function - Google Patents

Abstract

The present invention relates to a subscriber premises device having a copy protection function, by using a line buffer, a control unit, and a digital encoder in a subscriber premises device that outputs data transmitted from video on demand, so that this data has a copy protection function. Prevents unauthorized copying of data by others.

Description

Subscriber premise device with copy protection

1 is a block diagram showing a video & graphic data output unit in a conventional subscriber premises apparatus.

2 is a block diagram showing a video & graphic data output unit in a subscriber premises according to the present invention.

* Explanation of symbols for main parts of the drawings

1: CPU 2 ': MPEG video data decoder

3: graphic decoder 4: line buffer

5: line buffer control unit 6: digital NTSC encoder

The present invention provides a subscriber premises having a copy protection function for copying a menu screen and an image displayed on a display device by adding a copy protection function to a portion outputting video data and graphic data in a subscriber premises device having a copy protection function. Relates to a device.

In general, an analog signal is encoded and output when the video data and graphic data of a subscriber premises device (Set Top Box: STB) currently used are output. A central processing unit (1) which receives the data input from the video (VOD) and separates it into an audio signal and a video signal and outputs it to the MPEG decoder 2; An MPEG decoder 2 for decoding and outputting MPEG audio / video data input from the central processing unit 1; A graphic decoder (3) for outputting graphic data previously stored under the control of the central processing unit (1) and graphic data input through the central processing unit (1); A D / A converter (4) for converting digital data output from the MPEG decoder (2) into analog data; An analog switch unit (5) for switching and outputting respective data output from the D / A converter (4) and the graphic decoder (3); Analog R, G, and B encoders 6 for encoding and outputting data and luminance and chromaticity signals to be displayed on a display device (not shown) by using analog data output through the analog switch unit 5. Consisting of; The data provided by the graphic decoder 3 is font data or the like necessary for displaying screens and characters (or application implementations) on a display device; The analog R, G, and B encoders 6 encode a three primary color signal representing red, green, and blue that can reproduce all colors when reproducing a picture or a color image on a CRT. Do it.

Referring to the data output operation of the STB configured as described above, when the subscriber's request is required to display menus and images on the display device (TV CRT), the MPEG data stored in the video server on demand is input through the central processing unit 1. Receive.

The CPU 1 divides the input data into audio data and video data, and outputs the data to the MPEG decoder 2. The MPEG decoder 2 decodes the data and outputs the D / D signal. It is converted into analog data through the A converter 4 and input to the analog switch unit 5.

Meanwhile, a graphic screen such as a character or a chart required to display the MPEG data on the display device is decoded by the graphic decoder 3 under the control of the CPU 1 and then input to the analog switch unit 5. do.

The analog switch unit 5 receiving the respective signals is switched and outputted to the analog R, G, and B encoders 6, and then the signals are encoded and converted into data, luminance signals, and chroma signals. do.

The data output from the STB through the above process is displayed on each subscriber T.V screen, the subscriber is provided with a convenient service.

However, in the above process, the data displayed on the subscriber's display device does not contain a signal to prevent copying in the analog signal, which is the final output signal, so that copying of others cannot be prevented, and the final output signal is in the analog state. Because of this, it was inconvenient to control.

Therefore, in order to solve the conventional problems as described above, the present invention additionally configures an encoder having a copy protection function at an output unit for outputting MPEG data and graphic data in a subscriber premises device, and to use the encoder. It is an object of the present invention to provide a copy protection function that prevents copying of final output data by additionally configuring a line buffer having a function of matching a rate of data.

That is, in a subscriber station device (STB) including an MPEG data decoder and a graphic decoder, a line buffer for receiving and storing data output from the graphic decoder and changing the rate of the data when outputting the data is output. Wow; A line buffer control unit for providing a clock having a different rate during write and read operations of the line buffer to enable a ray conversion of data input and output from the line buffer; An MPEG video decoder for decoding MPEG video data and a digital NTSC encoder for digitally encoding data input from the line buffer to prevent unauthorized copying of data are implemented.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings, and the conventional configuration will be described with the same reference numerals.

In order to achieve the object of the present invention, the final output data, luminance signal, and chroma signal must be used as digital signal states. In order to use the digital signal, the MPEG video signal rate and the graphic signal rate are equalized at the output stage. There are conditions that must be met.

In the present invention, a line buffer is used to satisfy the above conditions, thereby satisfying the conditions for implementing the present invention by equalizing the rates of each data. As shown in FIG. A central processing unit (1) for receiving the data input from the) and separating the audio signal and the video signal to the MPEG decoder (2); An MPEG video data decoder 2 'that decodes and outputs MPEG video data input from the central processing unit 1; A graphic decoder (3) for outputting graphic data previously stored under the control of the central processing unit (1) and graphic data input through the central processing unit (1); A line buffer (4) for receiving and storing a rate of 24-bit data output from the graphic decoder (3), and then changing the rate of the data upon outputting the same; A line buffer control section (5) for providing a clock of a different rate during rate and read operation to enable rate conversion of data input / output in the line buffer (4); A digital NTSC encoder (hereinafter referred to as the US Television System Committee), which digitally encodes data input from the MPEG video data decoder 2 'and the line buffer 4 to prevent recording. ); The clocks input to the line buffer controller 5 are 13.5 MHz, 14 MHz, and 15.1 MHz, and are input from a clock generator (not shown) such as an oscillator.

Referring to the operation of the MPEG data output unit in the STB of the present invention configured as described above, the MPEG data transmitted from the video on demand is input to the central processing unit 1 in the STB is divided into MPEG audio data and MPEG video data, respectively, Is input to the decoder.

Among them, MPEG video data is input to the MPEG video data decoder 2 'and decoded. At this time, the input MPEG video data is input at a 24-bit 13.5MHz rate.

On the other hand, the graphic data output from the graphics decoder 3 has a data rate of 15.1 MHz or 14 MHz, which is a reset write signal RES input from the line buffer controller 5 when the data is stored in the line buffer 4. W) and the write enable signal WE are stored at the same clock as the data rate output from the graphic decoder 3.

When the stored data is output from the line buffer 4 again, the stored data is read in accordance with the reset read signal RES.R and the read enable signal RE input from the line buffer controller 5 to 13.5MHz. Output

Here, the output data is a total of 24 bits, of which 23 bits of the most significant bit (MSB) are input to the digital NTSC encoder 6 having a copy protection function and encoded, and the remaining 1 bit of the least significant bit is the MPEG video data decoder ( 2 ') output enable signal (VOE * (* means low active)).

Accordingly, the video data and the graphic data respectively input to the digital NTSC decoder 6 are input at the same 13.5 MHz speed, and these data are encoded and output as data having a copy protection function, a luminance signal, and a chroma signal. .

As described in detail above, the present invention uses a line buffer, a control unit, and a digital encoder in a subscriber indoor device that outputs data transmitted from video on demand so that a copy protection function is provided to another person so that unauthorized data is copied. Prevent it.

Claims (1)

In a subscriber premises device (STB) including an MPEG data decoder (2) and a graphics decoder (3), the data output from the graphics decoder (3) is received, stored, and then outputted. A line buffer 4 for varying and outputting; A line buffer control section (5) for providing a clock of a different rate during read operation and a rate of the line buffer (4) to enable rate conversion of data input / output in the line buffer (4); An MPEG video data decoder 2 'for decoding MPEG video data and a digital NTSC encoder 6 for digitally encoding data input from the line buffer 4 to prevent unauthorized copying of the data. A subscriber premises device having a copy protection function.