KR101465148B1 - Apparatus for encoding/decoding video and method thereof - Google Patents

Abstract

An apparatus and method for encoding / decoding moving images according to the present invention are disclosed. The apparatus for encoding a moving picture according to the present invention is characterized in that, when the moving picture data is inputted, the apparatus for coding the moving picture according to the present invention is characterized in that, when inputting the moving picture data, Measuring unit; And an output changing unit for randomly changing an output value for each coding unit on the basis of the measured reference frequency.

Description

[0001] APPARATUS FOR ENCODING / DECODING VIDEO AND METHOD THEREOF [0002]

More particularly, the present invention relates to an apparatus and method for encoding / decoding a moving image, and more particularly, to a method and apparatus for encoding / decoding a moving image, The output value is changed to an arbitrary value or the output value of a coding unit in a B frame not referring to an I or P frame is changed to an arbitrary value.

Generally, the digital image data is compressed by an efficient compression method, rather than being used as it is because the amount of data is increased in the process of digitizing the characteristics of the image and the analog signal itself.

Such a method of compressing digital image data can be divided into three methods, for example, 1) a method of reducing temporal redundancy, 2) a method of reducing spatial redundancy, and 3) a method of reducing using the statistical characteristics of generated codes And so on.

Of these compression methods, a typical method for reducing temporal redundancy is used in most moving picture compression standards such as Moving Picture Experts Group (MPEG) and H.264 as a motion estimation and compensation method.

According to the development of the compression technology, the quality of the decoded signal is improved. In the case of re-encoding the signal in an unacceptable situation, prevention of illegal copying is becoming an important issue.

Accordingly, it is an object of the present invention to provide a method and apparatus for measuring the number of reference frames in a B frame or a P frame for each coding unit in a frame in an I or P frame encoding process, And a method for encoding / decoding a moving picture that changes the output value of the moving picture coding apparatus to an arbitrary value.

It is another object of the present invention to provide an apparatus and method for encoding / decoding a moving picture that arbitrarily extracts a coding unit in a B frame not referring to an I or P frame and changes the output value.

However, the objects of the present invention are not limited to those mentioned above, and other objects not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided an apparatus for encoding a moving picture according to an aspect of the present invention, the apparatus comprising: A reference count measuring unit for measuring a reference count referenced by the reference count; And an output changing unit for randomly changing an output value for each coding unit based on the measured reference count.

Preferably, the reference frequency measuring unit measures the reference frequency referred to by different B frames or P frames for each coding unit in an I or P frame constituting each GOP of the inputted moving picture data.

Preferably, the output changing unit measures the number of times referred to by the consecutive frames and randomly changes the output value for each coding unit based on the reference number.

Preferably, the output changing unit measures the number of times the reference is referred to at the same position, and randomly changes the output value for each coding unit based on the reference number.

Preferably, the output changing unit randomly selects a coding unit output value of a B frame which does not refer to an I or P frame constituting each GOP of the inputted moving picture data, and changes the output value thereof.

Preferably, the output changing unit selects a position of the coding unit to be changed so that the position of the coding unit to be changed does not continuously arrive at the same position when the coding unit to be changed is selected.

According to another aspect of the present invention, there is provided an apparatus for decoding moving picture data, the apparatus including: a decoding unit for decoding the received moving picture data upon receiving the encoded moving picture data; And an output changing unit for randomly extracting output values of block units having a predetermined size from the decoded moving image data and randomly changing output values of the block units extracted.

Preferably, the output changing unit selects a position in a unit of a block which is changed so that the position of a block unit to be changed does not continuously arrive at the same position when selecting a coding unit to be changed.

According to another aspect of the present invention, there is provided a method for encoding a moving picture, the method comprising: receiving, when the moving picture data is input, a reference number referred to by different frames for each coding unit in a plurality of frames constituting each GOP of the input moving picture data; ; And randomly changing an output value for each coding unit based on the measured reference count.

Preferably, the measuring step measures the number of references referred to by different B frames or P frames for each coding unit in an I or P frame constituting each GOP of the input moving image data.

Preferably, the modifying step measures the number of times referred to by the continuous frame, and randomly changes the output value for each coding unit based on the reference number.

Preferably, the modifying step measures the number of times the reference is made at the same position, and randomly changes the output value for each coding unit based on the reference number.

Preferably, the changing step may randomly select a coding unit output value of a B frame not referring to an I or P frame constituting each GOP of the inputted moving picture data, and change the output value thereof.

Preferably, the changing step selects a position of a coding unit which is changed so that the position of the changed coding unit does not continuously arrive at the same position when selecting the changed coding unit.

According to another aspect of the present invention, there is provided a method of decoding moving picture data, the method including decoding a received moving picture data upon receiving encoded moving picture data; And randomly extracting the output value of the block unit having a predetermined size from the decoded moving image data and randomly changing the extracted output value of the block unit.

Preferably, the changing step selects a position of a block unit which is changed so that the position of the block unit to be changed does not continuously arrive at the same position when selecting a coding unit to be changed.

Accordingly, the present invention measures the number of times of reference in a B frame or a P frame for each coding unit in a frame in the encoding process of an I or P frame, and changes the output value of the coding unit in which the measured reference frequency is small to an arbitrary value Thus, when the decoded signal is re-encoded, image quality deterioration is caused to prevent illegal copying.

In addition, the present invention applies a method of measuring the number of times referred to in a B frame or a P frame for each coding unit and changing the output value of the coding unit in which the number of times of reference is small, to an arbitrary value. There is an advantageous effect.

1 is a block diagram illustrating an apparatus for encoding a moving picture according to an exemplary embodiment of the present invention.
FIG. 2 is a view for showing the number of times of reference by pixel according to an embodiment of the present invention.
FIG. 3 is a diagram illustrating the number of references per coding unit according to an exemplary embodiment of the present invention. Referring to FIG.
4 is a first diagram illustrating a method for encoding a moving picture according to an embodiment of the present invention.
5 is a second diagram illustrating a method for encoding a moving picture according to an embodiment of the present invention.
FIG. 6 is a block diagram illustrating an apparatus for decoding moving pictures according to an embodiment of the present invention. Referring to FIG.
7 is a diagram showing an example of referring to the same coding unit in successive frames.
8 is a diagram showing an example in which the same coding unit is referred to in non-continuous frames.
9 is a diagram showing an example of referring to the same coding unit at the same position.
10 is an illustration showing an example of referring to the same coding unit at another position.
11 is a diagram illustrating a method for decoding a moving picture according to an embodiment of the present invention.

Hereinafter, an apparatus and method for encoding / decoding a moving picture according to an embodiment of the present invention will be described with reference to the accompanying drawings. The present invention will be described in detail with reference to the portions necessary for understanding the operation and operation according to the present invention.

In describing the constituent elements of the present invention, the same reference numerals may be given to constituent elements having the same name, and the same reference numerals may be given thereto even though they are different from each other. However, even in such a case, it does not mean that the corresponding component has different functions according to the embodiment, or does not mean that the different components have the same function. It should be judged based on the description of each component in the example.

In particular, in the present invention, the number of times of reference in a B frame or a P frame is measured for each coding unit in an I or P frame, and the output value is changed for each coding unit according to the measured reference number, We propose a new method that can prevent illegal copying by generating significant image quality degradation when re - encoding.

Also, in the present invention, it is possible to arbitrarily extract a coding unit in a B frame not referring to an I or P frame, and to change an output value of the extracted coding unit.

At this time, most of the moving picture codec standards such as MPEG2, H.264, H.265 and the like in the moving image coding are coded by a coding unit (CU), and these coding units are generally rectangular Shape.

1 is a block diagram illustrating an apparatus for encoding a moving picture according to an exemplary embodiment of the present invention.

1, an apparatus for encoding a moving picture according to the present invention includes an image input unit 110, an encoding unit 120, a reference count measuring unit 130, an output changing unit 140, and the like. .

The video input unit 110 may receive video data through wired or wireless communication.

The encoding unit 120 may encode the input moving image data using a predetermined coding standard method.

In order to code the encoded moving picture data on a GOP (Group Of Picture) basis, the reference count measuring unit 130 may include a plurality of frames constituting each GOP, that is, an I frame (Infra Frame), a B frame (Bidirectional Frame) It is possible to measure the number of references from the B frame or the P frame for each coding unit in the I or P frame among the Predicted Frame.

That is, in order to code the input moving picture data in units of GOPs, the reference number measuring unit 130 classifies the reference moving picture data into GOP units composed of a plurality of frames, and I or P frames The reference count is measured for each coding unit. The method of measuring the reference frequency can be performed by performing a primary coding process on the input moving image and then measuring the reference frequency for each coding unit of the I and P frames.

The GOP may be composed of a plurality of frames. For example, the GOP may include I, B, B, P, B, B, P, B, B, P, . ≪ / RTI > That is, P frames are inserted between I frames, and B frames are inserted between I frames and P frames.

Here, the I frame represents data that is compressed and restored by itself without reference to other images. The P frame is compressed and restored by using the previous I frame information and the previous P frame information, and the B frame represents data for which compression and restoration are performed using both the previous and subsequent I frame and P frame .

FIG. 2 is a view for showing the number of times of reference by pixel according to an embodiment of the present invention.

As shown in Fig. 2, the reference frequency from the B frame or the P frame can be measured for each pixel of the moving picture data. For example, in a codec, moving picture data is restored using a reference picture and a motion vector, and the reference count is counted every time a specific pixel is referred to.

In this way, the reference counts measured for each pixel are different from each other, in which (a) is the original moving picture data and (b) shows the reference map showing the number of times of reference by the pixel in the moving picture data. That is, the reference count from the B frame or the P frame may be different for each coding unit.

FIG. 3 is a diagram illustrating the number of references per coding unit according to an exemplary embodiment of the present invention. Referring to FIG.

As shown in FIG. 3, a pixel-by-pixel map can be averaged over a coding unit of a predetermined size. (a) is a coding unit map and (b) shows a reference map averaged by a coding unit. In general, rather than being referred to as a coding unit, only some pixels of a coding unit are referred to. Therefore, when calculating the reference count of the coding unit, it is possible to calculate by weighting the actual reference area.

For example, if only 16 pixels corresponding to 1/4 of a total of 64 pixels in an 8x8 coding unit are used for actual reference, the corresponding coding unit can be regarded as being referenced 0.25 times.

The output changing unit 140 may change the output value for each coding unit based on the measured reference count. That is, the output changing unit 130 can randomly replace or change the output value of the coding unit in which the measured number of times of reference is smaller than the predetermined threshold value.

Here, an arbitrary value can be randomly selected within the range of 0 to 255.

For example, even if the output value of the coding unit in which the true view count is 2-3 or less is changed to a totally different value, the viewer hardly perceives it. It should be noted, however, that the positions of the changed coding units do not continuously arrive at the same position in order to avoid a change in image quality. When the decoder decodes compressed moving picture data whose output values of some of the coding units are changed and converts the decoded moving picture data into a digital signal and outputs the digital signal, the quality of the picture is deteriorated when the digital signal is re-encoded. The advantage of the moving picture encoding method according to the present invention is that illegal copy protection can be prevented without cooperation with the decoder.

At this time, the output changing unit 140 may increase the degree to which the output value is changed as the number of times of reference in other frames constituting one GOP is smaller, based on the measured reference count.

For example, when the pixel value is x, the reference number is changed to 0 when x> 128 and to 255 when x <= 128 when the reference number is 0. When the reference number is 5, x> 128, If x <= 128, it can be changed to 240.

In addition, the output changing unit 140 may arbitrarily extract a coding unit in a B frame not referring to an I or P frame as well as an I or P frame to change the output value. The position of the coding unit in the B frame thus changed is the same So that the user can not recognize the deterioration of image quality.

At this time, the output changing unit 140 may arbitrarily extract an output value of one coding unit in the B frame, but may optionally extract output values of a plurality of coding units.

4 is a first diagram illustrating a method for encoding a moving picture according to an embodiment of the present invention.

As shown in FIG. 4, an apparatus for encoding a moving picture according to the present invention (hereinafter, referred to as an encoding apparatus) can receive moving picture data through wired or wireless communication (S410).

Next, the encoding apparatus performs encoding using the general coding standard method for the input moving image data, and obtains a coding unit map of each frame as a result of performing the encoding (S420).

Next, the encoding apparatus calculates the number of references from the B frame or the P frame per coding unit in the I or P frame among the plurality of frames constituting each GOP of the encoded moving picture data, that is, the I frame, the B frame, and the P frame (S430).

Next, the encoding apparatus can change the output value for each coding unit based on the measured reference number (S440). Here, the encoding apparatus can adjust the degree to which the output value is changed according to the number of times of reference in the other frames constituting one GOP based on the reference count. For example, the encoding apparatus can increase the degree to which the output value is changed as the number of times the reference frame is referenced in other frames constituting one GOP.

At this time, when the encoding device changes the output value of the coding unit, the position of the changed coding unit is not generated continuously at the same position, so that the user can not recognize the deterioration.

Further, in changing the coding unit output value, the coding parameters can be adjusted by taking into consideration not only the number of references but also the number of consecutively referenced, the reference position, and the like. For example, when the coding unit output value is changed, the case where the specific coding unit is referred to in consecutive frames as shown in FIG. 7 may be lowered more significantly than the case where the reference is consecutively referred to as in FIG. 8. The coding unit output value can be changed by considering the number of consecutive references even if the same reference number is used.

In the case of changing the coding unit output value, the case where the specific coding unit is continuously referred to at the same position as shown in Fig. 9 may be further deteriorated in the bodily image quality as compared with the case where reference is made at another position as shown in Fig. In consideration of this, the coding unit output value can be changed by further considering the number of times that the same reference position is continuously referred to at the same position.

5 is a second diagram illustrating a method for encoding a moving picture according to an embodiment of the present invention.

As shown in FIG. 5, an apparatus for encoding a moving image according to the present invention (hereinafter, referred to as an encoding apparatus) can receive moving picture data through wired or wireless communication (S510).

Next, the encoding apparatus performs encoding using the general coding standard method on the input moving image data, and obtains a coding unit map of each frame as a result of performing the encoding (S520).

Next, the encoding apparatus calculates the number of references from the B frame or the P frame per coding unit in the I or P frame among the plurality of frames constituting each GOP of the encoded moving picture data, that is, the I frame, the B frame, and the P frame (S530).

Next, the encoding apparatus can change the output value for each coding unit based on the measured reference number (S540).

Next, the encoder may arbitrarily extract an output value of a coding unit of the B frame not referring to the I or P frame, and change the output value (S550).

FIG. 6 is a block diagram illustrating an apparatus for decoding moving pictures according to an embodiment of the present invention. Referring to FIG.

As shown in FIG. 6, the apparatus for decoding moving picture according to the present invention may include an image receiving unit 610, a decoding unit 620, and an output changing unit 630.

The image receiving unit 610 can receive the moving image coded by the wired or wireless communication.

The decoding unit 620 can decode the encoded moving image received from the image input unit 610. [

The output changing unit 630 may change the output value or the pixel value of the coding unit randomly extracted from the decoded moving image to an arbitrary value. That is, the output changing unit 630 can replace or change the output value of the coding unit whose measured number of times of reference is smaller than the preset threshold value to an arbitrary value.

That is, the present invention allows image quality deterioration to occur when a signal decoded by randomly changing an output value of a randomly extracted coding unit is re-encoded. In this case, the changed position can be extracted in units of coding units or pixels, and the changed position can be prevented from being continuously generated at the same position, so that the user can be prevented from recognizing the deterioration.

In this manner, in the embodiment of the present invention, the value of the coding unit having a small number of times to be referred to is arbitrarily changed in consideration of the number of times to be referred to by each coding unit, so that sudden image quality deterioration occurs when the decoded signal is re-encoded. The coding unit to be changed can be selected from I, P, and B frames. Also, the decoder changes the pixel values randomly extracted before outputting the decoded signal to an arbitrary value, and causes image quality deterioration when the decoded signal transmitted to the display is re-encoded.

11 is a diagram illustrating a method for decoding a moving picture according to an embodiment of the present invention.

As shown in FIG. 11, a device for decoding a moving picture according to the present invention (hereinafter referred to as a decoding device) can receive moving picture data by wired or wireless communication (S 1110).

Next, the decoding apparatus can decode the received encoded moving image (S1120).

Next, the decoding apparatus randomly extracts the output value or the pixel value of the coding unit from the decoded moving image, and changes the pixel value of the extracted coding unit to an arbitrary value (S1130). In this case, it is needless to say that the pixel values randomly extracted on a pixel-by-pixel basis can be changed to an arbitrary value.

It is to be understood that the present invention is not limited to these embodiments, and all of the elements constituting the embodiments of the present invention described above may be combined or operated in one operation. That is, within the scope of the present invention, all of the components may be selectively coupled to one or more of them. In addition, although all of the components may be implemented as one independent hardware, some or all of the components may be selectively combined to perform a part or all of the functions in one or a plurality of hardware. As shown in FIG. In addition, such a computer program may be stored in a computer-readable medium such as a USB memory, a CD disk, a flash memory, etc., and read and executed by a computer, thereby implementing embodiments of the present invention. As the storage medium of the computer program, a magnetic recording medium, an optical recording medium, a carrier wave medium, or the like may be included.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or essential characteristics thereof. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

110:
120:
120: reference count measuring unit
130:
610:
620:
630: Output changing section

Claims (16)

A reference count measuring unit for measuring a reference frequency referred to by different frames for each coding unit in a plurality of frames constituting each GOP of the inputted moving picture data when the moving picture data is input; And
An output changing unit for randomly changing an output value for each coding unit on the basis of the measured reference frequency;
And an encoding unit for encoding the moving picture. The method according to claim 1,
Wherein the reference-
And measures the reference frequency referred to by different B frames or P frames for each coding unit in an I or P frame constituting each GOP of the inputted moving picture data. The method according to claim 1,
Wherein the output changing unit comprises:
And measures the number of times referred to by the continuous frame, and randomly changes the output value for each coding unit based on the measured reference frequency. The method according to claim 1,
Wherein the output changing unit comprises:
And the output value is randomly changed according to the coding unit based on the measured reference frequency. The method according to claim 1,
Wherein the output changing unit comprises:
Wherein a coding unit output value of a B frame which does not refer to an I or P frame constituting each GOP of the inputted moving picture data is randomly selected and its output value is changed. The method according to claim 1,
Wherein the output changing unit comprises:
Wherein the position of the coding unit to be changed is selected so that the position of the coding unit to be changed does not continuously arrive at the same position when the coding unit to be changed is selected. A decoding unit for decoding the received moving picture data when the encoded moving picture data is received; And
An output changing unit for randomly extracting an output value of a coding unit having a predetermined size from the decoded moving image data and randomly changing an output value of the extracted coding unit;
Wherein the output changing unit randomly changes an output value for each coding unit based on a reference count referenced by different frames for each coding unit in a plurality of frames constituting each GOP of the moving picture data, A device for decoding a video. 8. The method of claim 7,
Wherein the output changing unit comprises:
Wherein the position of the coding unit to be changed is selected so that the position of the coding unit to be changed does not continuously arrive at the same position when the coding unit to be changed is selected. Measuring the number of references referred to by different frames for each coding unit in a plurality of frames constituting each GOP of the input moving picture data; And
Randomly changing an output value for each coding unit based on the measured reference number;
Wherein the moving picture coding method comprises the steps of: 10. The method of claim 9,
Wherein the measuring step comprises:
Wherein the reference number is referred to by different B frames or P frames for each coding unit in an I or P frame constituting each GOP of the inputted moving picture data. 10. The method of claim 9,
Wherein the modifying comprises:
Wherein the number of times of reference by the continuous frame is measured and the output value is randomly changed for each coding unit based on the reference number. 10. The method of claim 9,
Wherein the modifying comprises:
And the output value is randomly changed according to the coding unit based on the measured reference frequency. 10. The method of claim 9,
Wherein the modifying comprises:
Wherein a coding unit output value of a B frame which does not refer to an I or P frame constituting each GOP of the inputted moving picture data is randomly selected and its output value is changed. 10. The method of claim 9,
Wherein the modifying comprises:
When selecting a coding unit to be changed, selecting a position of a coding unit to be changed so that the position of the coding unit to be changed does not continuously arrive at the same position. A decoding step of decoding the received moving picture data when the encoded moving picture data is received; And
Randomly extracting an output value of a coding unit having a predetermined size from the decoded moving picture data and randomly changing an output value of the extracted coding unit;
Wherein the modifying step randomly changes the output value for each coding unit on the basis of the number of references referred to by different frames for each coding unit in the plurality of frames constituting each GOP of the moving picture data, A method for decoding a moving picture. 16. The method of claim 15,
Wherein the modifying comprises:
When selecting a coding unit to be changed, selecting a position of a coding unit which is changed so that the position of the coding unit to be changed does not continuously arrive at the same position.

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