JPH10210442A - Scramble method and device therefor, and dynamic image processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily apply scrambling to encoded video signals by applying scramble to video signals by means of plural start codes which are included in an encoded video stream. SOLUTION: An MPEG2 video data start code detection/change information output part 12 outputs the start code information on an MPEG2 video stream. The start code detection information and the start code change information, which are included in the start code information, are outputted to an MPEG2 video data start code detection part 13 and an MPEG2 video data start code change part 14, respectively. The part 13 detects a start code based on the start code detection information, and the part 14 changes the detected start code into another start code, based on the start code change information. Based on this start code change, the scramble is applied to the video data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scrambling method for scrambling a video signal, a scrambling device, and a moving image processing device. More specifically, the present invention relates to an MPEG (Moving) device.
The present invention relates to a scramble method for scrambling a video stream of a Picture Expert Group 2 system, a scramble device, and a moving image processing device.

[0002]

2. Description of the Related Art When a video signal is transmitted using a wireless transmission path, scrambling is indispensable in order to avoid energy concentration on a specific frequency, and when a video signal is transmitted using another transmission path. Also, scrambling is used for clock recovery and the like. In addition, scrambling is used for confidentiality purposes.

[0003] Video scrambling is generally performed in such a manner that inversion of a signal, suppression of a synchronization signal, and the like are temporally changed.

[0004] Conventional video scrambling techniques include the following.

[0005] 1. Line permutation method (scanning line transfer method): scrambling is performed by changing the order of scanning lines.

[0006] 2. Line rotation method (signal switching method within a scanning line): A scrambling is performed by providing a cut point in each scanning line and exchanging before and after the cut point.

[0007] 3. Skyport method: scrambling is performed by randomly replacing all scanning lines.

[0008] 4. Video cipher method: A method that uses both synchronization signal removal and polarity inversion.

[0009] 5. B-MAC method: Each scanning line length is changed at random.

[0010]

As described above, the conventional method is a scrambling method applied to a video signal, not a scramble method applied to encoded data, for example, an MPEG2 video stream. Was.

That is, the conventional scrambling system has a problem to be solved in that scrambling of the ΜPEG video stream is not considered.

[0012] The present invention provides a scrambling method for easily scrambling an encoded video signal,
An object of the present invention is to provide a scramble device and a moving image processing device.

[0013]

A scrambling method according to the present invention is a scrambling method for scrambling an encoded video stream, wherein the scrambling is performed on a video signal using a plurality of start codes in the video stream. It is characterized by multiplying.

The scrambling method according to the present invention is a scrambling method for scrambling an encoded video stream. First, a predetermined code value and a plurality of start codes arranged in a predetermined order in the video stream are provided. It is characterized in that a code is detected, the detected start code is changed and scrambled.

[0015] The above encoding is performed by MPEG (Moving Picture).
Expert Group) coding method or H.264. H.261 or the like, and the start code may be a start code in an MPEG2 video stream.

A scrambler according to the present invention is a scrambler for scrambling an encoded video stream, comprising scrambling means for scrambling a video signal using a plurality of start codes in the video stream. Configure.

The scrambling means may be configured to scramble by changing a predetermined code value and a plurality of start codes arranged in a predetermined order in the video stream.

The above-mentioned encoding is performed according to the MPEG encoding method or H.264. H.261 or the like, and the start code may be a start code in an MPEG2 video stream.

In the moving picture processing apparatus according to the present invention, in a moving picture processing apparatus for processing a data sequence having a predetermined data structure as a stream, start code changing means for changing a plurality of start codes indicating the start of processing in a video stream. And restoring means for restoring the changed start code.

The moving picture processing apparatus includes an encoding apparatus for performing encoding according to a predetermined encoding method, and a decoding apparatus for decoding a video encoded by the encoding apparatus. Start code detecting means for detecting a start code from the converted video data, start code changing means for changing the detected start code to another start code, changed start code, user data and encoding Multiplexing means for multiplexing the supplied audio data and transmitting the multiplexed audio data as a stream, wherein the decoding device comprises: a data separating means for separating the transmitted stream into video data, user data and audio data; A change start code detecting means for detecting a change start code from the inside; and And restoring means for restoring the Tokodo,
Decoding means for decoding the video data including the restored start code and outputting the decoded video data as a video signal.

The change of the start code by the start code changing means may be a change of the code value of the start code, and the change of the start code by the start code changing means may be performed by changing the appearance order of a plurality of start codes. It may be a change.

The above-mentioned encoding is performed according to the MPEG encoding method or H.264. H.261 or the like, and the start code may be a start code in an MPEG2 video stream.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A scrambling method according to the present invention,
The scramble device and the moving image processing device can be applied to a moving image processing device that scrambles an MPEG2 video stream.

FIGS. 1 and 2 are block diagrams showing a structure of a moving picture processing apparatus using a scrambling method and a scrambling apparatus according to an embodiment of the present invention. FIG.
FIG. 2 is a diagram showing an EG2 encoding device, and FIG. FIG. 3 is a diagram showing a layer structure of an MPEG2 video stream. For convenience of explanation, the layer configuration of the video stream in FIG. 3 will be described.

An international standard for coding moving pictures, especially moving pictures for storage media, is MPEG (Moving Picture E).
xpert Group).

As shown in FIG. 3, the MPEG data structure includes a block layer, a macroblock layer, a slice layer, a picture layer, a GOP (Group of Pictures) layer, and a video sequence layer. The contents are as follows.

The block layer is composed of pixels of 8 lines × 8 pixels adjacent to each other in luminance or color difference.
Rete Cosine Transform) is performed in this unit.

The macroblock layer includes four luminance blocks Y0, Y1, Y2, and Y3 adjacent to each other in the left, right, up, and down directions.
On the image, each of the color difference blocks of Cb and Cr at the same position is composed of a total of six blocks. The motion vector is handled on a macroblock basis.

The slice layer is composed of one or a plurality of macro blocks connected in the scanning order of the image.

The picture layer is composed of at least one or a plurality of slices described above, and is classified into an I picture, a P picture, a B picture and the like according to the encoding method.

The GOP layer is composed of one or more I pictures and zero or more non-I pictures.

The video sequence layer is composed of one or a plurality of GOPs having the same image size and image rate.

In MPEG, fast forward, rewind,
Since playback from the middle is fundamental, moving pictures of a certain unit are collectively formed to form a GOP (Group of Pictures) so that independent playback can be performed in that unit.

In this GOP, a sequence header (SH) can be added in order to enable reproduction from the middle of the GOP.
Contains initial data required for data reproduction, such as pixel aspect ratio.

By the way, when the present invention is applied to an actual application including an encoded stream (bit string) of MPEG video and MPEG audio, and other encoded streams, they are integrated into one unit including synchronization and integrated into one. It is necessary to convert the stream into a data format conforming to a unique physical format or protocol of a storage medium or a network.

The MPEG stream is a byte stream that has many 1-bit flags but is byte-aligned for each unit such as a header. As a structure common to the entire MPEG system, information indicating the length is placed before the data portion that is not fixed length, and when unnecessary, the portion is skipped, and the head of the next data group is checked and reliable. It has a data structure that enables highly-separable separation processing.

The basic concept of this embodiment will be described based on the layer structure of video data in MPEG2 shown in FIG.

As shown in FIG. 3, MPEG2 video data has seven individual start codes. That is, a sequence header coat, extension start code and user data start code in the sequence layer, a group start code in the GOP layer, a picture start code and extension start code in the picture layer, a slice start code in the slice layer, and a video This is the last sequence end code of the stream. The numerical value (H) in the figure indicates the hexadecimal code value of the start code.

The sequence header code appears at the beginning of the sequence layer, and indicates that data below the sequence layer follows.

The extension start code appears in the sequence layer and the picture layer, and indicates that extension data follows.

The user data start code appears in the sequence layer and indicates that user data follows.

The group start code appears at the beginning of the GOP layer, and indicates that data following the GOP layer follows.

The picture start code appears at the beginning of the picture layer, and indicates that data following the picture layer follows.

The slice start code appears at the beginning of the slice layer, and indicates that data following the slice layer follows.

The sequence end code appears at the end of the video stream and indicates that the video stream has been completed.

As shown in FIG. 3, these codes are the same codes up to the upper 24 bits and can be identified by the difference of the lower 8 bits. Also, these start codes appear in the layer shown in FIG. 3, and the order in which they appear also follows the order shown in FIG. 3. If this order is not satisfied, the decoding side will not be able to recognize as video data, causing an error, It cannot be converted to a video signal.

By taking advantage of this fact, the decoding side uses MPEG2
The video stream is scrambled so that it cannot be converted to a video signal.

FIG. 1 is a block diagram of an MPEG2 encoder for scrambling based on the above-described basic concept.

In FIG. 1, an MPEG2 encoding device 10
Are MPEG2 video data encoding unit 11, MPEG2 video data start code detection / change information output unit 12, M
PEG2 video data start code detecting section 13 (start code detecting means), MPEG2 video data start code changing section 14 (start code changing means), MPEG
2 user data section 15, MPEG2 audio data encoding section 16, and MPEG2 data multiplexing section 17 (multiplexing means)
Consists of

The MPEG2 video data encoding unit 11
Encodes a video signal in accordance with the MPEG2 encoding method and outputs the encoded video signal as MPEG2 video data.

The MPEG2 video data start code detection / change information output unit 12 is provided with the MPE shown in FIG.
The start code information of the G2 video stream is output. Among the start code information, the start code detection information is an MPEG2 video data start code detection unit 13.
Then, the start code change information is output to the MPEG2 video data start code change unit 14, respectively.

The MPEG2 video data start code detection unit 13 detects a start code from the encoded MPEG2 video data based on the start code detection information.

The MPEG2 video data start code change unit 14 changes the detected start code to another start code based on the start code change information. The scramble is applied to the video data by changing the start code.

The MPEG2 user data section 15 outputs the start data detection information and the start code change information on the user data.

The MPEG2 audio data encoding unit 16
Encodes an audio signal according to the MPEG2 encoding method and outputs the encoded audio signal as MPEG2 audio data.

The MPEG2 data multiplexing section 17 multiplexes the changed start code, user data, and coded audio data, and sends the multiplexed data to the line as MPEG2 multiplexed data.

FIG. 2 is a block diagram of an MPEG2 decoding apparatus for decoding the MPEG2 multiplexed data which has been scrambled and transmitted on the MPEG2 encoding side.

In FIG. 2, the MPEG2 decoding device 20
Is an MPEG2 data separation unit 21 (data separation means),
Password input unit 22, selectors 23 and 24, MPEG
2 user data section 25, MPEG2 video data change start code detection section 26 (change start code detection means), MPEG2 video data start code restoration section 27
(Decompression means), an MPEG2 video data decoding section 28 (decoding means) and an MPEG2 audio data decoding section 29.

The MPEG2 data separation section 21 separates the MPEG stream data received from the line into video data, user data and audio data.

The password input unit 22 is for inputting a password for descrambling. For example, keys for inputting alphanumeric characters, hiragana, etc., and function keys such as a cursor movement key and an execution key are arranged. Use the keyboard. When any key on the keyboard is operated, it is converted into a predetermined key code corresponding to the key by the keyboard controller, and the selectors 23 and 24 are switched.

According to the instructions from the password input unit 22, the selectors 23 and 24 restore the start code of the MPEG2 video data scrambled by the change of the start code, or select to output the start code as it is.

The MPEG2 user data section 25 detects the start code detection information and the start code change information from the user data, and outputs the start code detection information and the start code change information to the MPEG2 video data change start code detection section 26 as change start code information. M as code recovery information
The data is output to the PEG2 video data start code restoration unit 27, respectively.

The MPEG2 video data change start code detecting section 26 detects a change start code from the separated MPEG2 video data based on the change start code detection information.

The MPEG2 video data start code restoring unit 27 restores the detected changed start code to the original start code based on the start code restoration information.

The MPEG2 video data decoding section 28
Decodes video data in accordance with the
Output as a PEG2 video signal.

The MPEG2 audio data decoding section 29
Decodes audio data according to the MPEG2 system and
Output as PEG2 audio signal.

Next, the MPEG2 constructed as described above is used.
The operation of the encoding device 10 and the MPEG2 decoding device 20 will be described.

In FIG. 1, a video signal is input to an MPEG2 video data encoding unit 11, and the input video signal is converted into an MPEG2 video data by an MPEG2 video data encoding unit 11.
Encoding is performed based on the second method.

The MPEG2 video data start code detector 13 detects a start code from the encoded data.

The start code detected at this time is MP
It receives start code detection information from the EG2 video data start code detection / change information output unit 12 and determines which start code is to be detected based on the information.

The detected start code is input to the MPEG2 video data changing unit 14, which changes the detected start code to another code and outputs it to the MPEG2 data multiplexing unit 17.

At this time, in the MPEG2 user data section 15, the detection and change information performed by the MPEG2 video data start code detection / change information output section 12 to the MPEG2 video data start code detection section 13 and the MPEG2 video data start code change section 14 are transmitted. Is transmitted to the MPEG2 data multiplexing unit 17 along with the user data.

On the other hand, the audio signal is input to the MPEG2 audio data encoding unit 16, and the input audio signal is
The EG2 audio data encoding unit 16 encodes the data based on the MPEG2 method, and the MPEG2 data multiplexing unit 17
Is output to

The MPEG2 data multiplexing section 17 multiplexes the start code changed to another code, audio data, and user data and sends them to the line side.

Therefore, the MPEG transmitted on the line
The two-stream data has been scrambled by changing the start code.

On the decoding side in FIG. 2, the MPEG stream data received from the line side is separated by the MPEG2 data separation section 21 into video data, audio data, and user data.

The separated user data is input to the MPEG2 user data section 25. The MPEG2 user data section 25 detects, from the user data, information in which the start code of the video data has been changed. The MPEG2 video data change start code detection unit 26 receives the MP
The EG2 image data is output to the start code restoring unit 27.

The MPEG2 video data change start code detecting section 26 detects the changed start code based on the changed start code information, and converts the detected start code into the MPEG2 video data start code restoring section 2.
7 is output.

In the MPEG2 video data start code restoring section 27, the detected start code is restored to the original start code based on the start code restoring information detected by the MPEG2 user data section 25.
The data is sent to the video data decoding unit 28. The MPEG2 video data decoding unit 28 reproduces the video signal according to the restored start code, and outputs it to a video output device such as a monitor.

The encoded audio data is stored in the MPE
The signal is decoded by the G2 sound data decoding unit 29 and output as a sound signal.

When scrambling is performed on the decoding side, signal paths are selected by the selectors 23 and 24. The selectors 23 and 24 switch according to an instruction from the password input unit 22.

When scrambling, the video stream passes through the MPEG2 video data change start code detecting section 26 and the MPEG2 video data start code restoring section 27 and reaches the MPEG2 video data decoding section 28. The video data that has reached the MPEG2 video data decoding unit 28 is stored in the MPEG2
Since the start code changed by the video data start code changing unit 14 is not restored, a code that is not in the MPEG2 encoding system appears, and decoding cannot be performed.
Since an accurate video signal cannot be output, scrambling is performed.

Normally, on the encoding side, the start code is detected by the MPEG2 video data start code detecting section 13 and the MPEG2 video data start code changing section 1 is detected.
In step 4, the start code is changed, and the changed start code is multiplexed with audio data and user data to form an MPEG2
Send it out as a stream.

On the decoding side, upon receiving this MPEG2 stream, it is separated into video data, audio data and user data, and the video data bypasses the MPEG2 video data change start code detecting section 26 and the MPEG2 video data start code restoring section 27. So that the MPEG2 video data decoding unit 28 cannot decode it into a video signal.

When the descrambling is released, the MPEG2 video data change start code detecting section 26 and the MPEG2 video data start code restoring section 27 are operated by inputting a password or the like on the decoding side. MPEG2
The video stream is sent to the video data decoding unit 28 so that it can be accurately decoded into a video signal.

As described above, the scramble method, the scramble device, and the moving image processing device according to the present embodiment include the MPEG2 encoding device 10 and the MPEG2 decoding device 20, and the MPEG2 encoding device 10
EG2 video data encoding unit 11, MPEG2 video data start code detection / change information output unit 12, MPE for detecting a start code from encoded video data
G2 video data start code detector 13, MP for changing the detected start code to another start code
EG2 video data start code change unit 14, MPEG
A MPEG-2 data multiplexing unit 17 for multiplexing the modified start code, the user data and the coded audio data and transmitting the multiplexed audio data as a stream;
The PEG2 decoding device 20 separates the transmitted stream into video data, user data, and audio data.
EG2 data separation unit 21, password input unit 22, selectors 23 and 24, MPEG2 user data unit 25, MPEG2 video data change start code detection unit 2 for detecting a change start code from the separated video data
6. MPEG2 video data start code restoring unit 27 for restoring the detected changed start code to the original start code, MPEG2 video data decoding unit for decoding video data including the restored start code and outputting it as a video signal 28 and MPEG2 audio data decoding unit 2
9, the MPEG-2 video stream can be scrambled, and the decoding side can also be scrambled.

In particular, the input video signal is MPEG2
The data is encoded by the encoding device 10, scrambled using the start code of the MPEG2 video stream, and is decoded and decoded by the MPEG2 decoding device 20. That is, it is possible to easily scramble the video signal only by inputting the video signal.

Therefore, a scramble method, a scramble device and a moving image processing device having the above-mentioned excellent features can be provided by, for example, {generating a PEG2 video stream}.
It is suitable for application to a PEG system. As the ΜPEG stream, a movie or TV program that is converted into a ΜPEG stream can be considered.

In the above embodiment, the scramble method and the scramble device are applied to the moving picture processing device for generating the MPEG video stream. However, the video signal is transmitted using a plurality of start codes in the video stream. It is needless to say that the scrambling method or the scrambling device itself may be used as long as the scramble is applied to the video data. In other words, the present invention can be applied to a conventional scrambling method for scrambling a video signal and a scrambling device.

In the present embodiment, the MPEG system is implemented by MPEG2. However, the present invention can be applied to any moving image processing apparatus based on the MPEG algorithm or other encoding methods, and for example, necessary for realizing this method. The environment may be a dedicated machine externally equipped with a ΜPEG decoder or the like in addition to the computer.

The start code of the MPEG stream may be changed in any manner, for example, by changing the code value, changing the appearance order of the start code, or using both of them.

Further, it goes without saying that the number and types of circuits and members constituting the MPEG2 encoding device 10 and the MPEG2 decoding device 20 are not limited to the above-described embodiment, and may be realized by software. Good.

[0093]

The scrambling method and the scrambling apparatus according to the present invention scramble a video signal by using a plurality of start codes in an encoded video stream. The video signal can be scrambled.

The moving picture processing apparatus according to the present invention comprises start code changing means for changing a plurality of start codes indicating the start of processing in a video stream, and restoring means for restoring the changed start code. Therefore, the scrambling can be easily applied to the video signal only by inputting the video signal, and the scrambling can be easily applied to the decoding side.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a scrambling method, a scrambling device, and a coding device of a moving image processing device according to an embodiment to which the present invention is applied.

FIG. 2 is a block diagram illustrating a configuration of the scrambling method, the scrambling device, and a decoding device of the moving image processing device.

FIG. 3 is a diagram illustrating a layer configuration of an MPEG2 video stream of the scramble method, the scramble device, and the moving image processing device.

[Explanation of symbols]

10 MPEG2 encoding device, 11 MPEG2 video data encoding unit, 12 MPEG2 video data start code detection / change information output unit, 13 MPEG2 video data start code detection unit (start code detection means), 1
4 MPEG2 video data start code changing section (start code changing means), 15 MPEG2 user data section, 16 MPEG2 audio data encoding section, 17 MP
EG2 data multiplexing unit, 20 MPEG2 decoding device,
21 MPEG2 data separation unit (data separation means), 2
2 Password input unit, 23, 24 selector, 25M
PEG2 user data section, 26 MPEG2 video data change start code detection section (change start code detection section), 27 MPEG2 video data start code restoration section (recovery section), 28 MPEG2 video data decoding section (decoding section), 29 MPEG2 Audio data decoding unit

Claims (14)

[Claims] 1. A scrambling method for scrambling an encoded video stream, comprising scrambling a video signal using a plurality of start codes in the video stream. 2. A scrambling method for scrambling an encoded video stream, comprising: first detecting a predetermined code value and a plurality of start codes arranged in a predetermined order in the video stream; A scrambling method characterized by applying a scramble by changing a start code. 3. The method according to claim 1, wherein the encoding is performed by a moving picture (MPEG).
re Expert Group) coding method or H.264. 3. The scrambling method according to claim 1, wherein the encoding is based on an international standard encoding system such as H.261. 4. The scrambling method according to claim 1, wherein the start code is a start code in an MPEG2 video stream. 5. A scrambler for scrambling an encoded video stream, comprising: a scrambler for scrambling a video signal using a plurality of start codes in the video stream. Scramble device. 6. The apparatus according to claim 1, wherein said scrambling means is configured to scramble the video stream by changing a predetermined code value and a plurality of start codes arranged in a predetermined order. Item 6. The scrambler according to Item 5. 7. The method according to claim 1, wherein the encoding is performed by MPEG (Moving Pictu).
re Expert Group) coding method or H.264. The scrambler according to claim 5, wherein the encoding is based on an international standard encoding system such as H.261. 8. The scrambler according to claim 5, wherein the start code is a start code in an MPEG2 video stream. 9. A moving image processing apparatus for processing a data sequence having a predetermined data structure as a stream, comprising: start code changing means for changing a plurality of start codes indicating the start of processing in a video stream; A moving image processing apparatus comprising: a restoration unit for restoring. 10. The moving picture processing device according to claim 9, wherein: a coding device that performs coding by a predetermined coding method; and a decoding device that decodes a video coded by the coding device. The encoding device further includes: a start code detecting unit that detects a start code from encoded video data; a start code changing unit that changes the detected start code to another start code; Multiplexing means for multiplexing the modified start code, user data, and encoded audio data and transmitting the multiplexed audio data as a stream, wherein the decoding device separates the transmitted stream into video data, user data, and audio data. Data separation means for detecting a change start code from the separated video data Detecting means, restoring means for restoring the detected changed start code to the original start code, and decoding means for decoding video data including the restored start code and outputting the decoded data as a video signal. A moving image processing device characterized by the above-mentioned. 11. The moving image processing apparatus according to claim 9, wherein the change of the start code by the start code changing means is a change of a code value of the start code. 12. The method according to claim 9, wherein the change of the start code by the start code changing means is a change of an appearance order of a plurality of start codes.
The moving image processing device according to any one of claims 1 to 7. 13. The encoding method according to claim 1, wherein the encoding is MPEG (Moving Pic).
ture Expert Group) coding method or H.264. The moving image processing apparatus according to claim 9, wherein the encoding is based on an international standard encoding method such as H.261. 14. The moving picture processing apparatus according to claim 9, wherein the start code is a start code in an MPEG2 video stream.