JPH08130727A - Method and device for processing moving image - Google Patents

Abstract

PURPOSE: To secure the flexibility of the change of a scramble system by setting the key information of a motion vector code and converting the vector code based on the key information on a transmission side and extracting the key information and inversely converting the vector code on a reception side. CONSTITUTION: A conversion key code inputted from a key code input part is transmitted to a code conversion part and set as data for converting the motion vector code. In the user area code addition part of a bit stream working processing part, the inputted conversion key code is set in the user data area of the respective GOP layers of a bit stream. Also, in a motion vector extraction part, the motion vector code is extracted from the bit stream. The code is transmitted to the code conversion part, converted by a prescribed conversion system, then transmitted to a motion vector code replacement part and replaced with an original motion vector code, that is, scrambled. The bit stream for which the motion vector code is converted in such a manner is transmitted to an outside.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process of scrambling compressed moving image data and a process of decoding the scrambled compressed moving image data.

[0002]

2. Description of the Related Art A user data area is provided in a bit stream conforming to the MPEG of a moving picture coding standard, and various kinds of information regarding a screen corresponding to the user data area can be arbitrarily set. .

Japanese Patent Laid-Open No. 6-90451 discloses CCI.
H.T. of TT recommendation 261 and a scramble method of a moving image are disclosed by converting a motion vector code in compressed data of a moving image according to the MPEG standard into another code word in a codebook that has different code lengths and shows different values. Has been done.

[0004]

SUMMARY OF THE INVENTION In a transmission / reception system in which a moving image to be scrambled and transmitted can be viewed only by a person who has a paid reception contract with the sender, the following request is made. is there.

There is a request to "make it possible to make a contract for each program". That is, if contracts can be made for each program, the unit price of each contract can be lowered, and an increase in the number of contractors can be expected. In addition, the viewer does not have to feel dissatisfied with paying a fee for an unnecessary program, which reduces psychological resistance to a pay contract. However, it is necessary to change the scramble system for each program in order to be able to make a contract for each program. For this reason, it is desired to make it possible to decipher a plurality of types of scrambling methods, preferably by only changing the software without making a large change in the hardware.

There is a demand that "the scramble system can be easily changed to prevent illegal viewing." That is,
If the scramble system is fixed, a person who decrypts the system may watch the program without paying the fee. In order to prevent this, it is necessary to change the scramble system and the decryption system at any time, preferably by only changing the software without making a large change in the hardware. Further, in order to prevent the subscriber from being prevented from viewing despite this change, it is necessary that the decryption key after the change is present in the transmission data.

There is a request to "show the outline of the program even for non-contractors." In other words, although you cannot view the detailed contents of the program, if you can view a certain screen or part of it,
It can be expected to evoke the desire to make a contract for the program. It is an object of the present invention to meet the above requirements.

[0008]

According to the present invention, conversion key information of a motion vector code is set on the transmitting side in compressed data obtained by compressing a moving image by encoding including motion compensation, and the conversion is performed. A moving image processing method, in which a motion vector code is converted based on key information, the conversion key information is extracted from the compressed data on the receiving side, and the motion vector code is inversely converted based on the conversion key information. is there. In the above, the compressed data may be a bit stream conforming to the moving picture coding standard MPEG, and the conversion key information may be set in the user data area of the bit stream. In that case, the user data area is set to GOP.
It may be a user data area of a layer.

Further, according to the present invention, input means for inputting conversion key information, and conversion of the conversion key information into motion vector code in compressed data obtained by compressing a moving image by encoding including motion compensation. The moving image processing apparatus includes a setting unit that sets as key information and a conversion unit that converts a motion vector code based on the conversion key information. In the above, the compressed data may be a bit stream conforming to the MPEG of the moving picture coding standard, and the setting means may set the conversion key information in the user data area of the GOP layer of the bit stream.

Further, according to the present invention, the extracting means for extracting the conversion key information from the compressed data obtained by compressing the moving image by the encoding including the motion compensation, and the motion vector code reverse based on the conversion key information. And a moving image processing device having an inverse transforming unit for transforming. In the above, the compressed data may be a bit stream conforming to the MPEG of the moving picture coding standard, and the extraction means may extract the conversion key information from the user data area of the GOP layer of the bit stream.

[0011]

On the transmitting side, the conversion key information of the motion vector code is set in the compressed data (for example, a bit stream conforming to MPEG) obtained by compressing the moving image by the encoding including the motion compensation. The motion vector code is converted based on the conversion key information. That is, scrambling is performed. On the receiving side, the conversion key information is extracted from the compressed data, and the motion vector code is inversely converted based on the conversion key information.

[0012]

Embodiments of the present invention will be described below. FIG. 1 is a block diagram showing the configuration of the transmitting side, and FIG. 2 is a block diagram showing the configuration of the receiving side. In the present embodiment, a motion vector conversion key code (information) is set in the user data area of the GOP layer in the MPEG-compliant bit stream on the transmission side, and the motion vector is converted based on the conversion key code. . Further, the conversion key code is extracted from the user data area on the receiving side, and the motion vector is inversely converted based on the conversion key code.

On the transmitting side, first, in the moving picture coding unit,
Video data is coded by a coding method including motion compensation. That is, predictive coding processing between screens is adaptively performed,
Further, after being subjected to DCT (discrete cosine transform) and quantization processing, variable length coding processing is performed to obtain an MPEG compliant bit stream. This bit stream is input to the bit stream processing unit.

The conversion key code of the motion vector is input in advance from the key code input section to the bit stream processing section. The key code input unit can be configured, for example, to input an arbitrary key code corresponding to a numerical value by using the numeric keypad, but the present invention is not limited to this, and a desired operation can be performed by pressing any one of a plurality of prepared operation buttons. A configuration for inputting a key code or a known input means such as a touch panel may be used.
The point is that it is possible to input a desired key code.

The conversion key code input from the key code input unit is also sent to the code conversion unit, and is set as data for converting the motion vector code in this code conversion unit. The motion vector code conversion method is, for example, the method disclosed in Japanese Patent Laid-Open No. 6-90451, that is, a key code is used as a key code for another code word in the code book that has the same code length but different values. A method of performing conversion according to a specified rule specified, a method of inverting the last bit of a motion vector code according to a specified rule specified by a key code, or the like can be adopted.

In the user area code addition section of the bit stream processing section, the conversion key code input from the key code input section is set in the user data area of each GOP layer of the bit stream. Also, the motion vector code extraction unit of the bitstream processing unit extracts a motion vector code from the bitstream. The motion vector code is sent to the code conversion unit and converted by the conversion method described above, and then sent to the motion vector code replacement unit of the bit stream processing unit to be replaced with the original motion vector code. That is, it is scrambled. The motion vector code-converted (= scrambled) bit stream is transmitted to the outside by the transmitter.

On the receiving side, the bit stream is received by the receiving device and sent to the compressed image decoding unit. In the compressed image decoding unit, the user area code extraction unit extracts the data of the user area of each GOP layer of the bit stream and sequentially sends the data to the key code extraction unit. The key code extraction unit sequentially extracts the key code from the transmitted user area data, and the key code is sent to the code inverse conversion unit.

In the code reverse conversion unit, data for reverse conversion of the motion vector code is set in order from the sent key code. The inverse conversion method is a method corresponding to the conversion method in the code conversion unit. That is, according to the predetermined rule specified by the key code, the code length is converted back to the original code word in the code book showing the same value and different value, or the motion vector code of the motion vector code is changed according to the predetermined rule specified by the key code. The last bit is re-inverted. The motion vector code is extracted in order by the motion vector code extraction unit and sent to the code inverse conversion unit.

The motion vector code thus restored to the original value by the code inverse conversion unit is sent to the motion vector processing unit and is replaced with the corresponding motion vector code. The bit stream in which the motion vector code has been restored to the original value in this way is decoded into moving image data by a normal MPEG decoding method, and the decoded moving image data is sent to the moving image output unit. As a result, the image is displayed.

As described above, in this embodiment, since the conversion key code is set in the user area of the bit stream and the receiving side performs the inverse conversion based on the conversion key code, the contract program is changed. It has the effect of flexibly responding to the increase. Further, since the conversion key code is set in the user data area of the GOP layer, even if the user starts watching the program halfway, there is an effect that the scramble is quickly canceled and the program can be viewed. It should be noted that this effect can be similarly achieved even with a configuration in which the conversion key code is set in the user data area of the picture layer.

[0021]

As described above, according to the present invention, the key information of the motion vector code is set on the transmitting side, the motion vector code is converted based on the key information, and the key information is extracted on the receiving side. In addition, since the motion vector code is inversely converted based on the key information, there is flexibility in changing the scramble system, and it is possible to easily change the scramble system by requesting "I want to be able to make a contract for each program". I want to prevent illegal viewing. " Further, since the scrambling is realized by converting the motion vector, it is possible to view the still image incompletely, and it is possible to meet the request of "I want to show the outline of the program to non-contractors".

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment apparatus on a transmission side.

FIG. 2 is a block diagram showing a configuration of a receiving-side embodiment device.

Claims (7)

[Claims] 1. A conversion key information of a motion vector code is set on the transmission side in compressed data obtained by compressing a moving image by encoding including motion compensation, and based on the conversion key information. A moving image processing method in which the motion vector code is converted by means of the conversion, the conversion side key information is extracted from the compressed data on the receiving side, and the motion vector code is inversely converted based on the conversion key information. 2. The moving image processing according to claim 1, wherein the compressed data is a bit stream compliant with MPEG of a moving image coding standard, and the conversion key information is set in a user data area of the bit stream. Method. 3. The moving image processing method according to claim 2, wherein the user data area is a GOP layer user data area. 4. Input means for inputting conversion key information, and the conversion key information is set as conversion key information of motion vector code in compressed data obtained by compressing a moving image by encoding including motion compensation. And a conversion unit that converts a motion vector code based on the conversion key information. 5. The compressed data according to claim 4, wherein the compressed data is a bit stream compliant with MPEG of a moving picture coding standard, and the setting means includes the conversion key information in a user data area of a GOP layer of the bit stream. Set the video image processing device. 6. Extraction means for extracting conversion key information from compressed data obtained by compressing a moving image by encoding including motion compensation, and inverse conversion for inversely converting a motion vector code based on the conversion key information. A moving image processing apparatus comprising: 7. The compressed data according to claim 6, wherein the compressed data is a bit stream compliant with MPEG of a moving picture coding standard, and the extraction means extracts the conversion key information from a user data area of a GOP layer of the bit stream. A video processing device that extracts