CN108696750A - A kind of decision method and device of prediction mode - Google Patents

Abstract

The invention discloses a method for judging a prediction mode, which includes: obtaining a prediction image in each prediction mode, obtaining the number of estimated coding bits in each prediction mode; The difference statistical operation is performed on the pixel values in the image, and the result of the difference statistical operation is determined as the distortion value in each prediction mode; according to the preset quantization parameter value, the distortion value in each prediction mode and the prediction Estimate the number of coding bits, and calculate the cost value in each prediction mode; judge the prediction mode according to the type of the slice to which it belongs and the cost value. The invention also discloses a judgment device of the prediction mode at the same time.

Description

Judgment method and device for a prediction mode

technical field

The present invention relates to the field of video communication, in particular to a method and device for judging a prediction mode.

Background technique

Intra-frame prediction mode and inter-frame prediction mode are two important prediction modes in video compression. Taking the H.265/HEVC standard as an example, for video coding of continuous dynamic images, each frame can be divided into I frame, P frame and B frame. There are three types of frames. For an I frame, the prediction mode of each coding unit is an intra prediction mode; but for a P frame and a B frame, the prediction mode of each coding unit may be an intra prediction mode or an inter prediction mode mode, so a decision needs to be made through rate-distortion optimization.

For high-definition video, in order to improve the performance of inter-frame coding, motion estimation and motion vector prediction are used to obtain inter-frame predicted pixel values. In the prior art, it is first necessary to calculate the residual value of the original image and the intra-frame predicted image, the residual value of the original image and the motion estimation predicted image, and the residual value of the original image and the motion vector predicted image; The data is transformed, quantized, dequantized, and inversely transformed to obtain three sets of reconstructed images; then the distortion value of the reconstructed image and the original image is calculated, and the number of bits of the encoded prediction information and residual is estimated, and finally judged by the law of rate distortion Get the prediction mode of the current coding unit. However, as the number of motion vector candidates increases, this method performs transformation, quantization, inverse quantization and inverse transformation operations on the residual data, and estimates the number of predicted coding bits of the residual information, which makes the hardware resource overhead of the encoder very big.

Contents of the invention

In order to solve the problems existing in the prior art, the embodiments of the present invention expect to provide a prediction mode judgment method and device for judging the prediction mode of the coding unit, which can save the hardware resource overhead of the encoder.

In order to achieve the above object, technical solution of the present invention is achieved in that way:

An embodiment of the present invention provides a method for judging a prediction mode, and the method includes:

Obtain the predicted image in each prediction mode, and obtain the estimated number of coding bits in each prediction mode;

performing a difference statistical operation on the pixel values in the predicted image in each prediction mode and the pixel values in the original image, and determining the result of the difference statistical operation as the distortion value in each prediction mode;

Calculate the cost value in each prediction mode according to the preset quantization parameter value, the distortion value in each prediction mode and the estimated number of coding bits;

The prediction mode is determined according to the type of the slice to which it belongs and the cost value.

In the above solution, the acquisition of the number of estimated coding bits in each prediction mode includes:

Obtain the estimated number of coding bits in the intra prediction mode; based on the preset motion vector difference method in the motion estimation mode, estimate and obtain the estimated coding bit number in the motion estimation mode; obtain the motion vector prediction mode as a preset value The estimated number of encoded bits for .

In the above solution, the difference statistical operation is performed on the pixel values in the predicted image and the pixel values in the original image in each prediction mode, and the result of the difference statistical operation is determined as the Distortion values include:

Calculate the sum of the squares of the difference between the pixel value in the predicted image and the pixel value in the original image in each prediction mode;

Determining the sum of squared differences in each prediction mode as the distortion value in each prediction mode.

In the above solution, the calculation of the cost value in each prediction mode according to the preset quantization parameter value, the distortion value in each prediction mode and the estimated number of coding bits includes:

Determine the Lagrangian coefficient of the quantization parameter value according to the preset quantization parameter value;

Multiply the number of estimated coding bits in each prediction mode by the Lagrangian coefficient, and add the result of the multiplication to the distortion value in each prediction mode to obtain the down the cost value.

In the above solution, the type of the slice includes I slice, P slice and B slice; the inter prediction mode includes motion estimation mode and motion vector prediction mode; , making a decision on the prediction mode includes:

If the type of the slice to which it belongs is an I slice, determine the prediction mode as an intra prediction mode;

If the type of the slice to which it belongs is a P slice or a B slice, determine whether the cost value in the intra prediction mode is smaller than the cost value in the motion estimation mode and whether it is smaller than the cost value in the motion vector prediction mode; if so, predict The mode is determined to be an intra-frame prediction mode; if not, the prediction mode is determined to be an inter-frame prediction mode.

The embodiment of the present invention also provides a prediction mode judgment device, which includes: an acquisition module, a distortion value calculation module, a cost value calculation module and a judgment module; wherein,

The obtaining module is used to obtain the predicted image in each prediction mode, and obtain the estimated number of coding bits in each prediction mode;

The distortion value calculation module is used to perform a difference statistical operation on the pixel value in the predicted image and the pixel value in the original image in each prediction mode, and determine the result of the difference statistical operation as the value of each prediction Distortion value in mode;

The cost value calculation module is used to calculate the cost value in each prediction mode according to the preset quantization parameter value, the distortion value in each prediction mode and the estimated number of coding bits;

The judging module is configured to judge the prediction mode according to the slice type and the cost value.

In the above solution, the acquisition module is specifically used to obtain the estimated number of coding bits in the intra prediction mode; based on the preset motion vector difference method in the motion estimation mode, estimate and obtain the estimated coding bits in the motion estimation mode Number; get the estimated coding bit number as the preset value in the motion vector prediction mode.

In the above solution, the distortion value calculation module includes: a statistical unit and a first determination unit; wherein,

The statistical unit is used to count the sum of squares of the difference between the pixel value in the predicted image and the pixel value in the original image in each prediction mode;

The first determining unit is configured to determine the sum of squared differences in each prediction mode as the distortion value in each prediction mode.

In the above solution, the cost value calculation module includes: a second determination unit and an acquisition unit; wherein,

The second determination unit is configured to determine the Lagrangian coefficient of the quantization parameter value according to the preset quantization parameter value;

The acquisition unit is configured to multiply the estimated number of coding bits in each prediction mode by the Lagrangian coefficient, and add the result of the multiplication to the distortion value in each prediction mode, A cost value in each prediction mode is obtained.

In the above solution, the types of the slices include I slices, P slices and B slices; the inter prediction mode includes motion estimation and motion vector prediction; the decision module includes: a first decision unit and a second decision unit. Judgment unit; where,

The first decision unit is configured to determine the prediction mode as an intra prediction mode if the type of the slice to which it belongs is an I slice;

The second judgment unit is configured to judge whether the cost value in the intra prediction mode is smaller than the cost value in the motion estimation mode and whether it is smaller than the cost value in the motion vector prediction mode if the type of the slice to which it belongs is a P slice or a B slice. cost value; when the cost value in the intra prediction mode is less than the cost value in the motion estimation mode and less than the cost value in the motion vector prediction mode, the prediction mode is determined as the intra prediction mode; when the intra prediction mode If the cost value under is greater than or equal to the cost value in the motion estimation mode, or greater than or equal to the cost value in the motion vector prediction mode, then the prediction mode is determined to be the inter-frame prediction mode.

The prediction mode judgment method and device provided by the embodiments of the present invention are used to judge the prediction mode of the coding unit; firstly, obtain the predicted image in each prediction mode, and obtain the estimated number of coding bits in each prediction mode; then, Perform a difference statistical operation on the pixel values in the predicted image in each prediction mode and the pixel values in the original image to calculate the distortion value in each prediction mode; then, according to the preset quantization parameter value, each The distortion value in the prediction mode and the estimated number of coding bits are used to calculate the cost value in each prediction mode; finally, the prediction mode is judged according to the type of the slice to which it belongs and the cost value.

It can be seen that in the embodiment of the present invention, when calculating the distortion value of the coding unit in each prediction mode, it is not necessary to reconstruct the image on the basis of the residual image to obtain the real distortion value; instead, it is only necessary to obtain the predicted image and calculate the A difference statistical operation is performed on the pixel value of the coding unit in the original image and the pixel value in the predicted image to obtain a predicted distortion value. Since it is necessary to add transformation, quantization, inverse quantization, and inverse transformation operations on the basis of the residual image, and it is necessary to estimate the number of residual bits, the operations of transformation, quantization, inverse quantization, and inverse transformation and the estimation of the number of residual bits will be The hardware resource overhead of the encoder is greatly increased; therefore, the embodiment of the present invention can greatly save the hardware resource overhead of the encoder and reduce the complexity of the encoder hardware design under the premise of ensuring the encoding quality by reducing the above steps.

Description of drawings

Fig. 1 is a schematic diagram of the implementation flow of Embodiment 1 of the judgment method of the prediction mode of the present invention;

FIG. 2 is a schematic diagram of a detailed flow chart of performing a difference statistical operation in the implementation process shown in FIG. 1 and determining the result of the difference statistical operation as the distortion value in each prediction mode;

FIG. 3 is a schematic diagram of a refinement process for calculating the cost value in each prediction mode in the implementation process shown in FIG. 1;

FIG. 4 is a schematic diagram of a detailed flow for making a decision on a prediction mode in the implementation flow shown in FIG. 1;

FIG. 5 is a schematic diagram of the composition and structure of Embodiment 1 of the judgment device for the prediction mode of the present invention;

Fig. 6 is a schematic diagram of the refined composition structure of the distortion value calculation module in the device shown in Fig. 5;

Fig. 7 is a schematic diagram of the refined composition structure of the cost value calculation module in the device shown in Fig. 5;

FIG. 8 is a schematic diagram of a detailed composition structure of the decision module in the device shown in FIG. 5 .

Detailed ways

The prediction mode judgment method provided by the embodiment of the present invention is mainly used in the encoder to judge the prediction mode of the coding unit; by reducing the transformation, quantization, inverse quantization and inverse transformation added on the basis of the residual image The operation and the estimation operation of the number of residual bits can greatly save the hardware resource overhead of the encoder under the premise of ensuring the encoding quality.

The realization of the purpose of the present invention, functional characteristics and advantages will be further described in conjunction with the embodiments and with reference to the accompanying drawings. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

Fig. 1 is a schematic diagram of the implementation flow of Embodiment 1 of the method for determining the prediction mode of the present invention. Referring to Fig. 1, the method for determining the prediction mode of this embodiment includes the following steps:

Step 101, obtaining the predicted image in each prediction mode, and obtaining the estimated number of coding bits in each prediction mode;

Generally, during the video encoding and decoding process of the H.265/HEVC encoding standard, each frame of image will be divided into several slices, and the slice type may be I slice, P slice or B slice. At the same time, a slice includes multiple coding units. For the P slice and the B slice, the prediction mode of each coding unit may be an intra prediction mode or an inter prediction mode. Therefore, when the video image is compressed in the encoder, it is necessary to determine the prediction mode of each coding unit in the encoder, so as to realize the correct compression encoding of the video image; the method for determining the prediction mode in this embodiment is applied to the encoder , used to determine the prediction mode of the coding unit.

Here, the prediction mode includes an intra prediction mode and an inter prediction mode, and the inter prediction mode includes a motion estimation mode and a motion vector prediction mode; therefore, in this embodiment, each prediction mode includes an intra prediction mode prediction mode, motion estimation method in inter prediction mode, and motion vector prediction method in inter prediction mode. Correspondingly, obtaining the prediction image of the coding unit in each prediction mode includes: obtaining the prediction image of the coding unit in the intra prediction mode, the motion estimation mode and the motion vector prediction mode respectively; obtaining the prediction image of the coding unit The estimated number of coding bits in each prediction mode includes: acquiring the estimated number of coding bits of the coding unit in the intra prediction mode, the motion estimation mode and the motion vector prediction mode respectively. The acquisition of the predicted image and the estimated number of coding bits will be described in detail below.

Specifically, how to obtain a prediction image of a coding unit in an intra prediction mode is firstly introduced. By selecting the preferred intra prediction mode in the current coding unit from the intra prediction modes, and calculating the intra prediction image IntraPredImage according to the preferred intra prediction mode.

It should be noted that there are multiple prediction strategies for intra-frame prediction of luma and chrominance of coding units, so an optimal intra-frame prediction strategy should be selected in practical applications. For the intra prediction of the luminance and chroma of the coding unit, the preferred intra prediction mode in the current coding unit can be selected from the corresponding 35 intra prediction modes; as for the strategy of selecting the preferred intra prediction mode, since this strategy is not in Within the key protection scope of the present invention, so it will not be elaborated.

Then, how to obtain the prediction image of the coding unit in the motion estimation mode is introduced. Through motion estimation, the motion vector SearchMV is obtained; and through the search motion vector interpolation, the interframe prediction image InterSearchImage under the motion estimation mode is obtained.

Next, how to obtain the predicted image of the coding unit in the motion vector prediction mode is introduced. Through motion prediction, the motion vector family PredMV is obtained; among them, PredMV(0) represents the 0th candidate motion vector, PredMV(1) represents the 1st candidate motion vector, PredMV(i) represents the i-th candidate motion vector, and so on . Taking the i-th candidate motion vector PredMV(i) as an example, the interprediction image InterPredImage(i) in the motion vector prediction mode is obtained through interpolation.

Next, how to obtain the estimated number of coding bits of the coding unit in the intra prediction mode is introduced. The estimated number of encoded bits is recorded as bits(Intra), and the acquisition steps are as follows:

Obtain the most probable intra prediction mode list of the current coding unit, that is, the MPM (Most Probable Mode) mode list, including 3 MPM modes, marked as MPM[0], MPM[1] and MPM[2]. If the prediction mode of the current coding unit is not in the MPM mode list, the bits(Intra) of the current coding unit is 6; if the intra prediction mode of the current coding unit is equal to MPM[0], the bits(Intra) of the current coding unit is 2; If the intra prediction mode of the current coding unit is equal to MPM[1] or MPM[2], the bits (Intra) of the current coding unit is 3.

Next, how to obtain the estimated number of coding bits of the coding unit in the motion estimation mode is introduced. The obtaining the estimated number of coding bits of the coding unit in the motion estimation mode includes: based on the preset motion vector difference method in the motion estimation mode, estimating and obtaining the estimated number of coding bits in the motion estimation mode, the estimated The number of encoded bits is recorded as bits(Search), and the acquisition steps are as follows:

Note that the LIST0 direction motion vector obtained by the current coding unit through motion estimation is mv_list0, and the mv_list0 vector includes the horizontal motion vector component mv_list0_x and the vertical motion vector component mv_list0_y;

Note that the first motion vector in the LIST0 direction obtained by the current coding unit through the motion vector prediction method is mvp_list0, and the vector mvp_list0 includes the horizontal motion vector component mvp_list0_x and the vertical motion vector component mvp_list0_y;

Calculate the absolute value of the horizontal direction motion vector component difference by formula (1), be recorded as mvdx; and calculate the absolute value of the vertical direction motion vector component difference by formula (2), be recorded as mvdy;

mvdx=abs(mvp_list0_x-mv_list0_x) (1)

mvdy=abs(mvp_list0_y-mv_list0_y) (2)

Get the position of the most significant bit in mvdx and mvdy. If the most significant bit of mvdx is at bit N, the estimated number of encoded bits of mvdx is N×2, which is recorded as Bits(mvdx); if the highest bit of mvdy is at bit M, the estimated number of encoded bits of mvdy is M ×2, denoted as Bits(mvdy). The estimated number of coding bits in the motion estimation mode in the final inter-frame prediction mode is the sum of the estimated coding bits of mvdx and the estimated coding bits of mvdy plus 2, as shown in formula (3):

bits(Search)=2+Bits(mvdx)+Bits(mvdy) (3)

Here, through a fast motion vector difference, the estimated number of coding bits of the coding unit in the motion estimation mode is estimated, and the number of bits required for coding the residual is not calculated, thereby saving the hardware resource overhead of the encoder .

Next, how to obtain the estimated number of coding bits of the coding unit in the motion vector prediction mode is introduced. The estimated number of coding bits of the coding unit in the motion vector prediction mode is a preset value; obtaining the estimated number of coding bits of the coding unit in the motion vector prediction mode includes: obtaining the preset value, the estimated The number of encoded bits is recorded as bits(Pred(i)); the preset value can be set according to actual needs, and the preset value is obtained by summarizing a large number of image encodings. In this embodiment, the preset value is set to 4, That is, bits(Pred(i))=4.

Here, by fixing the estimated number of coded bits of the coding unit in the motion vector prediction mode, the steps of estimating the estimated number of coded bits are reduced, which can greatly reduce the cost of computing rate-distortion required in the decision-making process of the prediction mode , saving the hardware resource overhead of the encoder.

Step 102, performing a difference statistical operation on the pixel values in the predicted image in each prediction mode and the pixel values in the original image, and determining the result of the difference statistical operation as the distortion value in each prediction mode;

Here, when calculating the distortion value of the coding unit in each prediction mode, it is only necessary to perform a difference statistical operation on the pixel value of the current coding unit in the original image and the pixel value in the predicted image, without Transformation, quantization, inverse quantization and inverse transformation operations need to be added on the basis of the difference image, so that the hardware resource overhead of the encoder can be saved.

Fig. 2 is a schematic diagram of a refinement process for performing difference statistical calculations and determining the results of difference statistical calculations as the distortion values in each prediction mode in the implementation process shown in Fig. 1, referring to Fig. 2, step 102 is specifically Include the following steps:

Step 1021, counting the sum of squares of differences between the pixel values in the predicted image and the pixel values in the original image in each prediction mode;

Step 1022: Determine the sum of squared differences in each prediction mode as the distortion value in each prediction mode.

Here, the sum of the squares of the difference between the pixel value of the coding unit in the original image and the pixel value in the predicted image in the intra prediction mode is calculated by formula (4), and the intra prediction of the current coding unit is obtained. Distortion value in mode;

Among them, curCU represents the current coding unit, Distortion(Intra) represents the distortion value of the current coding unit in the intra prediction mode, OrgImage(x,y) represents the pixel value of the current coding unit in the original image, IntraPredImage(x,y) Indicates the pixel value in the predicted image of the current coding unit in intra prediction mode.

Calculate the sum of the squares of the difference between the pixel value of the coding unit in the original image and the pixel value in the predicted image in the motion estimation mode by formula (5), to obtain the distortion of the current coding unit in the motion estimation mode value;

Wherein, Distortion(Search) represents the distortion value of the current coding unit in the motion estimation mode, and InterSearchImage(x,y) represents the pixel value in the prediction image of the current coding unit in the motion estimation mode.

Calculate the sum of the squares of the difference between the pixel value of the coding unit in the original image and the pixel value in the predicted image in the motion vector prediction mode by formula (6), and obtain the current coding unit in the motion vector prediction mode the distortion value;

Among them, Distortion(Pred(i)) represents the distortion value of the current coding unit in the motion vector prediction mode, and (InterPredImage(i))(x,y) represents the pixels in the predicted image of the current coding unit in the motion vector prediction mode value.

Step 103, calculating the cost value in each prediction mode according to the preset quantization parameter value, the distortion value in each prediction mode and the number of estimated coding bits;

Here, for luminance coding, the quantization parameter has 52 values in total, and takes an integer value from 0 to 51; wherein, when the quantization parameter value takes the minimum value of 0, it means that the quantization is the finest; on the contrary, when the quantization parameter value takes When the maximum value is 51, it means that the quantization is the roughest; theoretically, the quantization parameter value can be set to any integer value within the range of 0 to 51, and in this embodiment, the quantization parameter value can be set to 20.

FIG. 3 is a schematic diagram of a detailed flow diagram for calculating the cost value in each prediction mode in the implementation flow shown in FIG. 1. Referring to FIG. 3, step 103 specifically includes the following steps:

Step 1031, according to the preset quantization parameter value, determine the Lagrangian coefficient of the quantization parameter value;

Here, the Lagrangian coefficient can be set according to actual needs, specifically according to the quantization parameter value; in this embodiment, the Lagrangian parameter is selected through experiments according to the quantization parameter value a set of coefficients.

Step 1032: Multiply the estimated number of coding bits in each prediction mode by the Lagrangian coefficient, and add the result of the multiplication to the distortion value in each prediction mode to obtain the - The cost value in the prediction mode.

Here, the cost value of the coding unit in the intra prediction mode can be calculated by formula (8);

Cost(Intra)＝Distortion(Intra)+λ*bits(Intra) (8)

Wherein, Cost(Intra) is the cost value of the coding unit in the intra prediction mode.

Here, the cost value of the coding unit in the motion estimation mode can be calculated by formula (9);

Cost(Search)＝Distortion(Search)+λ*bits(Search) (9)

Wherein, Cost(Search) is the cost value of the coding unit in the motion estimation mode.

Here, the cost value of the coding unit in the motion vector prediction mode can be calculated by formula (10);

Cost(Pred(i))=Distortion(Pred(i))+λ*bits(Pred(i)) (10)

Wherein, Cost(Pred(i)) is the cost value of the coding unit in the motion vector prediction mode.

Step 104: Make a decision on the prediction mode according to the type of the slice to which it belongs and the cost value.

Here, the types of slices may include I slices, P slices, and B slices.

FIG. 4 is a schematic diagram of a detailed flow for making a decision on the prediction mode in the implementation flow shown in FIG. 1. Referring to FIG. 4, step 104 specifically includes the following steps:

Step 1041, if the type of the slice to which it belongs is an I slice, determine the prediction mode as the intra prediction mode;

Step 1042, if the type of the slice to which it belongs is a P slice or a B slice, determine whether the cost value in the intra prediction mode is smaller than the cost value in the motion estimation mode and whether it is smaller than the cost value in the motion vector prediction mode; if so, Then determine the prediction mode as the intra-frame prediction mode; if not, determine the prediction mode as the inter-frame prediction mode.

It can be understood that, by comparing the cost value of the coding unit in the intra prediction mode with the cost value of the coding unit in the inter prediction mode, the prediction mode of the coding unit can be adjusted. The decision is because: the above cost value refers to the degree of distortion between the original image of the coding unit and the predicted image in each prediction mode, and the correlation between the coding rate; when the coding unit is in a certain The smaller the cost value in the prediction mode, the higher the coding efficiency of the coding unit in the prediction mode, that is, the less image distortion can be obtained at the smallest possible coding rate. And when the cost value of the coding unit in the intra prediction mode is smaller than the cost value of the coding unit in the inter prediction mode, that is, the coding efficiency of the coding unit in the intra prediction mode is higher than that of the coding unit The coding efficiency of the unit in the inter-frame prediction mode, so it can be determined that the prediction mode of the coding unit is the intra-frame prediction mode, and vice versa.

The present invention also provides a prediction mode judgment device, which is used to realize the specific details of the prediction mode judgment method of the present invention and achieve the same effect.

FIG. 5 is a schematic diagram of the composition and structure of Embodiment 1 of the judgment device of the prediction mode of the present invention. Referring to FIG. 5 , the judgment device of the prediction mode in this embodiment includes: an acquisition module 21, a distortion value calculation module 22, and a cost value calculation module 23 And decision module 24; Wherein,

The obtaining module 21 is used to obtain the predicted image in each prediction mode, and obtain the estimated number of coding bits in each prediction mode;

The distortion value calculation module 22 is configured to perform a difference statistical operation on the pixel values in the predicted image and the pixel values in the original image in each prediction mode, and determine the result of the difference statistical operation as each Distortion value in predictive mode;

The cost value calculation module 23 is configured to calculate the cost value in each prediction mode according to the preset quantization parameter value, the distortion value in each prediction mode and the number of estimated coding bits;

The judging module 24 is configured to judge a prediction mode according to the type of the slice to which it belongs and the cost value.

Optionally, the acquisition module 21 is specifically configured to acquire the estimated number of coding bits in the intra prediction mode; based on the preset motion vector difference method in the motion estimation mode, estimate and obtain the estimated coding bit number in the motion estimation mode Number of bits; obtain the number of estimated coding bits as the preset value in the motion vector prediction mode.

Optionally, FIG. 6 is a schematic diagram of a detailed composition structure of the distortion value calculation module in the device shown in FIG. 5 . Referring to FIG. 6 , the distortion value calculation module 22 includes: a statistical unit 221 and a first determination unit 222; ,

The statistics unit 221 is used to calculate the sum of squares of differences between the pixel values in the predicted image and the pixel values in the original image in each prediction mode;

The first determining unit 222 is configured to determine the sum of squared differences in each prediction mode as the distortion value in each prediction mode.

Optionally, FIG. 7 is a schematic diagram of a detailed composition structure of the cost value calculation module in the device shown in FIG. ,

The second determination unit 231 is configured to determine the Lagrangian coefficient of the quantization parameter value according to the preset quantization parameter value;

The obtaining unit 232 is configured to multiply the estimated number of coding bits in each prediction mode by the Lagrangian coefficient, and add the multiplication result to the distortion value in each prediction mode , to obtain the cost value in each prediction mode.

Optionally, the types of the slices include I slices, P slices, and B slices; the inter prediction mode includes motion estimation and motion vector prediction; FIG. 8 is a detailed view of the decision module in the device shown in FIG. Composition structure diagram, as shown in FIG. 8, the decision module 24 includes: a first decision unit 241 and a second decision unit 242; wherein,

The first decision unit 241 is configured to determine the prediction mode as an intra prediction mode if the type of the slice to which it belongs is an I slice;

The second judging unit 242 is configured to judge whether the cost value in the intra prediction mode is smaller than the cost value in the motion estimation mode and whether it is smaller than the motion vector prediction mode if the type of the slice to which it belongs is a P slice or a B slice When the cost value in the intra-frame prediction mode is less than the cost value in the motion estimation mode and less than the cost value in the motion vector prediction mode, the prediction mode is determined as the intra-frame prediction mode; when the intra-frame prediction If the cost value in the mode is greater than or equal to the cost value in the motion estimation mode, or greater than or equal to the cost value in the motion vector prediction mode, then the prediction mode is determined as the inter-frame prediction mode.

In practical applications, the acquisition module 21, the distortion value calculation module 22, the cost value calculation module 23, the decision module 24, and the statistical unit 221, the first determination unit 222, the second determination unit 231, the acquisition unit 232, the first Judging unit 241 and the second judging unit 242 all can be positioned at central processing unit (CPU, Central Processing Unit), microprocessor (MPU, Micro ProcessorUnit), digital signal processor (DSP, Digital Signal Processor), application-specific integrated circuit (ASIC) in encoder (ASIC, Application Specific Integrated Circuit), or Field Programmable Gate Array (FPGA, Field Programmable Gate Array) and other implementations.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements and improvements made within the spirit and scope of the present invention are included in the protection scope of the present invention.

Claims (10)

1. A method for deciding a prediction mode, the method comprising:

obtaining a predicted image under each prediction mode, and obtaining a predicted coding bit number under each prediction mode;

performing difference value statistical operation on a pixel value in a predicted image and a pixel value in an original image under each prediction mode, and determining the result of the difference value statistical operation as a distortion value under each prediction mode;

calculating the cost value of each prediction mode according to a preset quantization parameter value, a distortion value and a pre-estimated encoding bit number under each prediction mode;

and judging the prediction mode according to the type of the strip and the cost value.

2. The method according to claim 1, wherein the obtaining the estimated encoding bit number in each prediction mode comprises:

acquiring the estimated coding bit number in an intra-frame prediction mode; estimating to obtain a pre-estimated coding bit number in a motion estimation mode based on a preset motion vector difference method in the motion estimation mode; and acquiring the estimated encoding bit number serving as a preset value in a motion vector prediction mode.

3. The method according to claim 1, wherein performing a difference statistic operation on pixel values in the predicted image and pixel values in the original image in each prediction mode, and determining a result of the difference statistic operation as the distortion value in each prediction mode comprises:

counting the pixel value in the predicted image in each prediction mode and the difference value square sum of the pixel value in the original image;

and determining the square sum of the difference values in each prediction mode as a distortion value in each prediction mode.

4. The method according to claim 1, wherein the calculating the cost value in each prediction mode according to the preset quantization parameter value, the distortion value in each prediction mode, and the estimated encoding bit number comprises:

determining a Lagrange coefficient of a quantization parameter value according to a preset quantization parameter value;

and multiplying the estimated encoding bit number under each prediction mode by the Lagrange coefficient, and adding the multiplication result and the distortion value under each prediction mode to obtain the cost value under each prediction mode.

5. The method of claim 1, wherein the types of stripes comprise I-stripes, P-stripes, and B-stripes; the inter-frame prediction mode comprises a motion estimation mode and a motion vector prediction mode; the judging the prediction mode according to the type of the belonged stripe and the cost value comprises:

if the type of the strip is an I strip, judging the prediction mode as an intra-frame prediction mode;

if the type of the strip is a P strip or a B strip, judging whether the cost value in the intra-frame prediction mode is smaller than the cost value in the motion estimation mode and is smaller than the cost value in the motion vector prediction mode; if yes, judging the prediction mode as an intra-frame prediction mode; if not, the prediction mode is judged as the inter-frame prediction mode.

6. An apparatus for deciding a prediction mode, the apparatus comprising: the device comprises an acquisition module, a distortion value calculation module, a cost value calculation module and a judgment module; wherein,

the obtaining module is used for obtaining a predicted image in each prediction mode and obtaining the estimated encoding bit number in each prediction mode;

the distortion value calculation module is configured to perform difference value statistical operation on a pixel value in a predicted image and a pixel value in an original image in each prediction mode, and determine a result of the difference value statistical operation as a distortion value in each prediction mode;

the cost value calculation module is used for calculating the cost value in each prediction mode according to a preset quantization parameter value, a distortion value in each prediction mode and an estimated encoding bit number;

and the judging module is used for judging the prediction mode according to the type of the strip to which the prediction mode belongs and the cost value.

7. The apparatus according to claim 6, wherein the obtaining module is specifically configured to obtain a predicted coding bit number in an intra prediction mode; estimating to obtain a pre-estimated coding bit number in a motion estimation mode based on a preset motion vector difference method in the motion estimation mode; and acquiring the estimated encoding bit number serving as a preset value in a motion vector prediction mode.

8. The apparatus of claim 6, wherein the distortion value calculation module comprises: a counting unit and a first determining unit; wherein,

the statistical unit is used for counting the pixel value in the predicted image under each prediction mode and the difference sum of squares of the pixel value in the original image;

the first determining unit is configured to determine a sum of squared differences in each prediction mode as a distortion value in each prediction mode.

9. The apparatus of claim 6, wherein the cost value calculation module comprises: a second determining unit and an acquiring unit; wherein,

the second determining unit is used for determining the Lagrangian coefficient of the quantization parameter value according to a preset quantization parameter value;

the obtaining unit is configured to multiply the estimated encoding bit number in each prediction mode by the lagrangian coefficient, and add a multiplication result to the distortion value in each prediction mode to obtain a cost value in each prediction mode.

10. The apparatus of claim 6, wherein the types of stripes comprise I-stripes, P-stripes, and B-stripes; the inter-frame prediction mode comprises a motion estimation mode and a motion vector prediction mode; the decision module comprises: a first decision unit and a second decision unit; wherein,

the first judgment unit is used for judging the prediction mode as an intra-frame prediction mode if the type of the strip is an I strip;

the second decision unit is configured to, if the type of the corresponding slice is a P slice or a B slice, determine whether a cost value in an intra prediction mode is smaller than a cost value in a motion estimation mode and smaller than a cost value in a motion vector prediction mode; when the cost value in the intra-frame prediction mode is smaller than the cost value in the motion estimation mode and smaller than the cost value in the motion vector prediction mode, judging the prediction mode as the intra-frame prediction mode; and when the cost value in the intra-frame prediction mode is more than or equal to the cost value in the motion estimation mode or more than or equal to the cost value in the motion vector prediction mode, judging the prediction mode as the inter-frame prediction mode.