CN111405292B - Video encryption method based on H.265 video coding standard - Google Patents

Abstract

The present invention relates to a kind of video encryption method based on H.265 video coding standard, it is characterized in that comprising the following steps: step (1), input the video frame sequence V _ori of original YUV format _; Two video frames begin to record the division information of all CUs of each video frame; Step (3), the Y component of each video frame in the copy V _ori forms a new video sequence V _y ; Step (4), V _y is processed, Obtain the foreground binary image P _sn ; Step (5), select the CU to be encrypted in the second video frame in _Vori ; Step (6), encode the current video frame according to the H.265 standard, divide in the CU Afterwards, the encryption operation is performed in two stages of entropy coding; step (7), continue to perform (5) (6) operations on the next video frame and so on; until the last video frame of _Vori is completed, thereby generating the encrypted video coding code flow. Compared with the prior art, the present invention not only has a better perceptual encryption effect, but also maintains a low computational complexity.

Description

A Video Encryption Method Based on H.265 Video Coding Standard

technical field

The invention relates to a video encryption method based on the H.265 video coding standard.

Background technique

The rapid development of video applications has covered various fields in our daily life. With the continuous high-definition of video pictures, ultra-high-definition video consumption has become the mainstream of online paid video applications. However, due to the anonymity and openness of the network, video data is often maliciously attacked during transmission, and the copyright of video information is also threatened. The continuous high-definition of video data is also accompanied by an increase in the amount of data, so new and more efficient video coding standards are constantly being updated. At present, a new generation of high efficiency video coding (High Efficiency Video Coding, HEVC for short) is gradually applied in video coding applications. In order to protect video resources more efficiently, it is necessary to combine video encryption methods and coding standards.

At present, the HEVC-based video encryption method mostly adopts the full frame encryption method, that is, the whole video frame is encrypted in three stages before encoding, transformation or entropy encoding, which has high encryption space and security. However, for the commercial use of high-definition video, the full-frame encryption method is highly computationally complex, requires high hardware and software, and takes a long time to process data, which is not conducive to real-time video communication.

Users pay more attention to the main content and quality of the video. Perceptual encryption of the main information in the video can not only reduce the computational complexity of the encryption method, but also reduce the quality of the video to a certain extent. It is impossible to obtain high-quality videos with accurate information, which plays a very good role in copyright protection.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a video encryption method based on the H.265 video coding standard, which can not only reduce the computational complexity but also enable a better encryption effect.

The technical scheme adopted by the present invention to solve the above-mentioned technical problems is: a video encryption method based on the H.265 video coding standard, which is characterized by comprising the following steps:

Step (1), input the video frame sequence of the original YUV format, the video frame sequence of the original YUV format is denoted as V _ori , and the size of the video frame is denoted as w*h;

Step (2), encoding the V _ori according to the H.265 standard, in the process of encoding according to the H.265 standard, perform intra-frame coding unit division on each video frame in the V _ori to obtain a plurality of coding units, The coding unit of the video frame to be encoded is marked as CU; the division information of all CUs of each video frame is recorded from the second video frame of V _ori , and stored in the first array vector1 in the form of (pt1x, pt1y, pt2x, pt2y) , where pt1x, pt1y, pt2x, and pt2y represent the abscissa of the upper left point, the ordinate of the upper left point, the abscissa of the lower right point, and the ordinate of the lower right point of the current CU respectively;

Step (3), the Y component of each video frame in the copy V _ori forms a new video sequence, and this new video sequence is marked as V _y ;

Step (4), V _y is processed, specifically comprises the following steps:

In step (4-1), two adjacent video frames of V _y are denoted as P _n and P _n+1 , and the difference value map P _dn is obtained after making a difference between the adjacent two video frames,

P _dn =|P _n -P _n+1 |, n = 1, 2, 3, ...;

In step (4-2), the difference map P _dn obtained in step (4-1) is binarized according to the preset threshold value T, and the corresponding binary images P _tn are obtained respectively, n=1, 2, 3, . . .; The binarization rule of the pixel in P _tn is: when the image value of the pixel in P _dn is greater than or equal to T, the image value of the corresponding position in P _tn is replaced with 255; when the image value of the pixel in P _dn is less than T , the image value of the corresponding position in P _tn is replaced by 0;

Step (4-3), perform first etching and post-dilation processing on P _tn , n=1, 2, 3, . . . to obtain a foreground binary image P _sn , n=1, 2, 3, . . .;

Step (5), select the CU to be encrypted in the second video frame in the V _ori , and save the horizontal and vertical coordinates of the upper left point of the CU in the second array vector2, and the specific steps include:

Step (5-1), the second video frame in V _ori corresponds to the binary image P _s1 , starting from the first CU of the second video frame, extract the horizontal and vertical coordinates in the corresponding binary image P _s1 one by one at the first CU. Each CU corresponds to the pixel value of the pixel in the range of the horizontal and vertical coordinates, and counts the pixels with a pixel value of 255. If the number exceeds K%, K is the preset threshold, the CU is determined as an encrypted CU, and the The horizontal and vertical coordinates (pt1x, pt1y) of the upper left point of the CU are stored in the second array vector2;

In step (5-2), each CU corresponds to a point in the first array vector1, and other CUs are executed according to the same method in step (5-1) until the point (pt1x, pt1y, pt2x, pt2y) satisfies pt2x=w -1, when pt2y=h-1, it means that the judgment of the current video frame is over;

Step (6), continue to encode the current video frame according to the H.265 standard, and in the encoding process according to the H.265 standard, perform an encryption operation on the current video frame after the CU is divided and two stages of entropy coding;

Step (7), emptying vector2, and continuing to perform operations (5) and (6) on the next video frame; the third frame corresponds to the binary image P _s2 , the fourth frame corresponds to the binary image P _s3 , and so on; until the completion of V _ori The last video frame, thereby generating the encrypted video code stream.

As an improvement, in the step 6, the specific operation steps include:

Step (6-1), to the CU to be encrypted in the video frame, perform Arnold transformation on its YUV three component data, if the size of the CU to be encrypted is 4*4, then perform 2 Arnold transformations, if to be encrypted If the size of the CU to be encrypted is 8*8, then perform 3 Arnold transformations, if the size of the CU to be encrypted is 16*16, then perform 4 Arnold transformations; if the size of the CU to be encrypted is 32*32, then perform 6 Arnold transformations;

Step (6-2), in the video frame entropy coding stage, perform XOR encryption on the symbols of the binary syntax element transform coefficients using the Logistic chaotic sequence.

Compared with the prior art, the advantage of the present invention is that the present invention locates the specific CU containing the moving object in the video frame by the frame difference method, only performs encryption operation on the part of the CU, and concentrates the calculation amount in the video which is more important. In the improved scheme, the scrambling in the CU stage and the encryption of the syntax elements in the entropy coding stage are combined, which increases the difficulty of cracking. Guaranteed high security.

Description of drawings

FIG. 1 is a flowchart of a video encryption method based on the H.265 video coding standard in an embodiment of the present invention. .

Detailed ways

The present invention will be further described in detail below with reference to the embodiments of the accompanying drawings.

The video encryption method based on the H.265 video coding standard as shown in Figure 1 is characterized in that it comprises the following steps:

Step (1), input the video frame sequence of the original YUV format, denote the video frame sequence of the original YUV format as V _ori , and the size of the video frame as w*h; the video sequence V _ori used is the standard test sequence BasketballDrill, where w = 832, h = 480;

Step (2), encoding the V _ori according to the H.265 standard, in the process of encoding according to the H.265 standard, perform intra-frame coding unit division on each video frame in the V _ori to obtain a plurality of coding units, The coding unit of the video frame to be encoded is marked as CU; the division information of all CUs of each video frame is recorded from the second video frame of V _ori , and stored in the first array vector1 in the form of (pt1x, pt1y, pt2x, pt2y) , where pt1x, pt1y, pt2x, and pt2y represent the abscissa of the upper left point, the ordinate of the upper left point, the abscissa of the lower right point, and the ordinate of the lower right point of the current CU, respectively;

Step (3), the Y component of each video frame in the copy V _ori forms a new video sequence, and this new video sequence is marked as V _y ;

Step (4), V _y is processed, specifically comprises the following steps:

In step (4-1), two adjacent video frames of V _y are denoted as P _n and P _n+1 , and the difference value map P _dn is obtained after making a difference between the adjacent two video frames:

P _dn =|P _n -P _n+1 |, n = 1, 2, 3, ...;

In step (4-2), the difference map P _dn obtained in step (4-1) is binarized according to the preset threshold value T, and the corresponding binary images P _tn are obtained respectively, n=1, 2, 3, . . .; The binarization rule of the pixel in P _tn is: when the image value of the pixel in P _dn is greater than or equal to T, the image value of the corresponding position in P _tn is replaced with 255; when the image value of the pixel in P _dn is less than T , the image value of the corresponding position in P _tn is replaced by 0; in this embodiment, T=50;

Step (4-3), perform first etching and post-dilation processing on P _tn , n=1, 2, 3, . . . to obtain a foreground binary image P _sn , n=1, 2, 3, . . .;

Step (5), select the CU to be encrypted in the second video frame in the V _ori , and save the horizontal and vertical coordinates of the upper left point of the CU in the second array vector2, and the specific steps include:

Step (5-1), the second video frame in V _ori corresponds to the binary image P _s1 , starting from the first CU of the second video frame, extract the horizontal and vertical coordinates in the corresponding binary image P _s1 one by one at the first CU. Each CU corresponds to the pixel values of the pixels within the horizontal and vertical coordinate ranges, and counts the pixels with a pixel value of 255. If the number exceeds K%, K is a preset threshold. In this embodiment, K is 50, and the The CU is designated as an encrypted CU, and the horizontal and vertical coordinates (pt1x, pt1y) of the upper left point of the CU are stored in the second array vector2;

In step (5-2), each CU corresponds to a point in the first array vector1, and other CUs are executed according to the same method in step (5-1) until the point (pt1x, pt1y, pt2x, pt2y) satisfies pt2x=w -1, when pt2y=h-1, it means that the judgment of the current video frame is over;

Step (6), continue to encode the current video frame according to the H.265 standard, and in the encoding process according to the H.265 standard, perform an encryption operation on the current video frame after the CU is divided and two stages of entropy coding;

Step (7), emptying vector2, and continuing to perform operations (5) and (6) on the next video frame; the third frame corresponds to the binary image P _s2 , the fourth frame corresponds to the binary image P _s3 , and so on; until the completion of V _ori The last video frame, thereby generating the encrypted video code stream.

In the above-mentioned step 6, the specific operation steps include:

Step (6-1), to the CU to be encrypted in the video frame, perform Arnold transformation on its YUV three component data, if the size of the CU to be encrypted is 4*4, then perform 2 Arnold transformations, if to be encrypted If the size of the CU to be encrypted is 8*8, then perform 3 Arnold transformations, if the size of the CU to be encrypted is 16*16, then perform 4 Arnold transformations; if the size of the CU to be encrypted is 32*32, then perform 6 Arnold transformations;

Step (6-2), in the video frame entropy coding stage, perform XOR encryption on the symbols of the binary syntax element transform coefficients using the Logistic chaotic sequence.

Claims (1)

1. A video encryption method based on H.265 video coding standard is characterized by comprising the following steps:

step (1), inputting a video frame sequence in an original YUV format, and recording the video frame sequence in the original YUV format as V_oriThe size of the video frame is marked as w x h;

step (2) of adding V_oriCoding according to H.265 standard, and in the process of coding according to H.265 standard, V is coded_oriEach video frame in the video coding unit is divided into a plurality of coding units, and the coding units of the video frames to be coded are marked as CU; from V_oriThe second video frame starts to record the partition information of all CUs of each video frame, and the partition information is stored in a first array vector1 in the form of (pt1x, pt1y, pt2x and pt2y), wherein pt1x, pt1y, pt2x and pt2y respectively represent the horizontal coordinate of the upper left point, the vertical coordinate of the upper left point, the horizontal coordinate of the lower right point and the vertical coordinate of the lower right point of the current CU;

step (3), copy V_oriY-score of each video frame in the video streamThe new video sequence is composed, marked as V_y；

Step (4), for V_yThe treatment specifically comprises the following steps:

step (4-1) of adding V_yIs marked as P_nAnd P_n+1Obtaining a difference map P by differencing two adjacent video frames_dn，

P_dn＝|P_n-P_n+1|，n＝1，2，3，…；

Step (4-2), and comparing the difference value graph P obtained in the step (4-1)_dnBinaryzation is carried out according to a preset threshold value T, and binary images P are correspondingly obtained respectively_tn，n＝1，2，3，…；P_tnThe binarization rule of the middle pixel point is as follows: when P is present_dnWhen the image value of the middle pixel point is more than or equal to T, P_tnReplacing the image value of the corresponding position with 255; when P is present_dnWhen the image value of the middle pixel point is less than T, P_tnThe image value of the corresponding position is replaced by 0;

step (4-3) for P_tnAnd n is 1,2,3, … to obtain foreground binary image P_sn，n＝1，2，3，…；

Step (5) of selecting V_oriAnd storing the horizontal and vertical coordinates of the upper left point of the CU in a second vector2, wherein the CU to be encrypted in the second video frame comprises the following specific steps:

step (5-1) of adding V_oriThe second video frame in (2) corresponds to a binary image P_s1Extracting the corresponding binary images P one by one from the first CU of the second video frame_s1The pixel values of the pixels of the middle horizontal and vertical coordinates in the horizontal and vertical coordinate range corresponding to the first CU are counted, if the number of the pixels of the middle horizontal and vertical coordinates exceeds K%, K is a preset threshold value, the CU is determined as an encrypted CU, and the horizontal and vertical coordinates (pt1x, pt1y) of the upper left point of the CU are stored in a second vector 2;

step (5-2), each CU corresponds to one point in the first array vector1, and other CUs are executed according to the same method in the step (5-1) until the points (pt1x, pt1y, pt2x, pt2y) meet the condition that pt2x is w-1 and pt2y is h-1, which indicates that the judgment of the current video frame is finished;

and (6) continuing to encode the current video frame according to the H.265 standard, and performing encryption operation in two stages of CU division and entropy coding in the process of encoding according to the H.265 standard, wherein the method specifically comprises the following steps:

performing Arnold transformation on YUV three component data of a CU to be encrypted in a video frame, performing 2 times of Arnold transformation if the size of the CU to be encrypted is 4 × 4, performing 3 times of Arnold transformation if the size of the CU to be encrypted is 8 × 8, and performing 4 times of Arnold transformation if the size of the CU to be encrypted is 16 × 16; performing 6 Arnold transformations if the size of the CU to be encrypted is 32 x 32;

step (6-2), carrying out XOR encryption on symbols of the binary syntax element transformation coefficients by using a Logistic chaotic sequence in the video frame entropy coding stage;

clearing the vector2, and continuing to execute the operations (5) and (6) on the next video frame; the third frame corresponds to the binary image P_s2The fourth frame corresponds to the binary image P_s3And so on in turn; until V is completed_oriAnd finally, generating an encrypted video coding code stream.

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