CN100579231C - A motion vector prediction method and device - Google Patents

Abstract

The invention discloses a motion vector prediction method and device. The method includes: when it is detected that the upper block and the left block of the current block are unavailable, but the upper two blocks and the left two blocks of the current block are available, determining the predicted motion vector of the current block according to the upper two blocks and the left two blocks, The upper two blocks of the current block are the upper blocks of the upper block of the current block, and the two left blocks of the current block are the left blocks of the left block of the current block. The invention improves the reliability of motion vector prediction.

Description

A motion vector prediction method and device

technical field

The present invention relates to the technical field of video coding, in particular to a motion vector prediction method and device.

Background technique

In the video coding standard, the spatial correlation method is used for motion vector prediction, that is, the motion vector of the coded block in the current frame is used as a reference, and the predicted motion vector of the current block is obtained through the median prediction criterion.

Figure 1 provides a schematic diagram of the existing motion vector prediction using the spatial correlation method, as shown in Figure 1, where Curr is the current block to be encoded, A, B, C, and D are encoded blocks in the current frame, And A is the left block of Curr, B is the upper block of Curr, C is the upper left block of Curr, and D is the upper right block of Curr. The correlations between A, B, C, D and Curr from high to low are: B, A, D, C.

Fig. 2 has provided the flow chart of the existing motion vector of utilizing spatial correlation method to predict Curr, as shown in Fig. 2, its specific steps are as follows:

Step 201: Determine whether A, B, D are all available, if yes, execute step 202, otherwise, execute step 203.

Generally, a block is considered unavailable when it satisfies one of the following two conditions:

1. The block is obtained by intra-frame prediction coding.

2. The block does not exist, for example, the block and Curr are not in the same slice (Slice), or the block exceeds the boundary of the frame.

Step 202: Use the median value of the motion vectors of A, B, and D as the predicted motion vector of Curr, and this process ends.

Step 203: Determine whether A and B are available, and D is unavailable, if yes, perform step 204; otherwise, perform step 207.

Step 204: Determine whether C is available, if yes, execute step 205; otherwise, execute step 206.

Step 205: Use the median value of the motion vectors of A, B, and C as the predicted motion vector of Curr, and this process ends.

Step 206: Use the zero vector as the motion vector of C, and then use the motion vectors of A, B, and C

The median value of is used as the predicted motion vector of Curr, and the process ends.

Step 207: Determine whether one of A and B is available, if yes, execute step 208; otherwise, execute step 209.

Step 208: Use the available motion vector of A or B as the predicted motion vector of Curr, and the procedure ends.

Step 209: Determine whether neither A nor B is available, but D is available. If yes, perform step 210; otherwise, perform step 211.

Step 210: Use the motion vector of D as the predicted motion vector of Curr, and the process ends.

Step 211: If it is determined that A, B, and D are not available, the zero vector is used as the predictive motion vector of Curr.

The disadvantage of the existing spatial correlation method to predict the motion vector is that when one of A and B is unavailable, the reliability of the motion vector prediction for Curr will be reduced, because: A and B are the most correlated with Curr Block, when both A and B are available, the prediction of Curr's motion vector is the most reliable, as long as one of A and B is not available, the reliability of the prediction of Curr's motion vector will be reduced.

Contents of the invention

The invention provides a motion vector prediction method and device to improve the reliability of motion vector prediction.

Technical scheme of the present invention is realized like this:

A motion vector prediction method, the method comprising:

When it is detected that the upper block and the left block of the current block are unavailable, but the upper two blocks and the left two blocks of the current block are available, the predicted motion vector of the current block is determined according to the upper two blocks and the left two blocks of the current block,

The upper two blocks of the current block are the upper blocks of the upper block of the current block, and the two left blocks of the current block are the left blocks of the left block of the current block.

The determining the predicted motion vector of the current block according to the upper two blocks and the left two blocks of the current block includes:

Determine whether the upper right block of the current block is available, if so, use the median of the motion vectors of the upper two blocks, the second left block, and the upper right block of the current block as the predicted motion vector of the current block; The average value of the motion vectors of the two blocks is used as the predicted motion vector of the current block.

The method further includes: when it is detected that the upper block, the left block, and the upper right block of the current block are all available, using the median value of the motion vectors of the upper block, the left block, and the upper right block of the current block as the predicted motion vector of the current block.

The method further includes: when both the upper block and the left block of the current block are available but the upper right block is unavailable, taking the average value of the motion vectors of the upper block and the left block of the current block as the predicted motion vector of the current block.

The method further includes: when one of the upper block and the left block of the current block is available, using the motion vector of the available upper block or the left block as the prediction motion vector of the current block.

The method further includes: when the upper block, the left block, the upper two blocks, and the left two blocks of the current block are not available, and the upper right block is available, using the motion vector of the upper right block as the predicted motion vector of the current block.

The method further includes: when the upper block, the left block, the upper right block, the second upper block, and the second left block of the current block are not available, using a zero vector as the predicted motion vector of the current block.

The method further includes: when the upper block, the left block, the upper right block, the second upper block, and the second left block of the current block are not available, assigning the same position in the reference frame as the current block in the current frame The motion vector of the block is used as the predicted motion vector of the current block.

A motion vector prediction device, the device comprising:

A block motion vector storage module stores motion vectors of blocks in the current frame;

The motion vector determining module, when detecting that the upper block and the left block of the current block are unavailable, and the upper two blocks and the left two blocks of the current block are available, according to the upper two blocks and the left two blocks of the current block obtained from the block motion vector storage module The motion vector of the second block determines the predicted motion vector of the current block.

The motion vector determination module includes:

The block available detection module detects whether the upper block, left block, upper second block, left second block, and upper right block of the current block are available, and sends the detection result to the determination module;

The determining module receives the detection result, if the detection result indicates that the upper block, the left block are unavailable, the upper two blocks, the left two block are available, and the upper right block is available at the same time, then the upper block of the current block obtained from the block motion vector storage module The median value of the motion vectors of the second block, the second left block, and the upper right block is used as the predicted motion vector of the current block; if the detection result indicates that the upper block and the left block are unavailable, the upper two blocks, the second left block are available, and the upper right block is unavailable , the mean value of the motion vectors of the upper two blocks and the two left blocks of the current block obtained from the block motion vector storage module is used as the predicted motion vector of the current block.

The determination module further includes, when the detection result indicates that the upper block, the left block, and the upper right block of the current block are all available, the motion of the upper block, the left block, and the upper right block of the current block obtained from the block motion vector storage module The median value of the vector is used as the sub-module of the predicted motion vector of the current block.

The determining module further includes, when the detection result indicates that both the upper block and the left block of the current block are available but the upper right block is not available, the motion vectors of the upper block and the left block of the current block obtained from the block motion vector storage module The mean is used as a submodule of the predicted motion vector for the current block.

The determination module further includes, when it is detected that one of the upper block and the left block of the current block is available, the motion vector of the available upper block or the left block acquired from the block motion vector storage module is used as the predicted motion of the current block Vector of submodules.

The determining module further includes, when it is detected that the upper block, the left block, the upper two blocks, the left two blocks, and the upper right block of the current block are unavailable, and the motion vector of the upper right block is used as the predicted motion vector of the current block of submodules.

The determining module further includes a submodule for using a zero vector as the predicted motion vector of the current block when it is detected that the upper block, the left block, the upper right block, the second upper block, and the second left block of the current block are not available.

The determining module further includes, when it is detected that the upper block, the left block, the upper right block, the second upper block, and the second left block of the current block are not available, the information obtained from the block motion vector storage module and in the reference frame The motion vector of the block whose position is the same as that of the current block in the current frame is used as a sub-module of the predicted motion vector of the current block.

Compared with the prior art, when the present invention detects that the upper block and the left block of the current block are not available, but the upper two blocks and the left two blocks of the current block are available, the current block is determined according to the upper two blocks and the left two blocks of the current block. The predicted motion vector of the block improves the reliability of the motion vector prediction.

Description of drawings

Fig. 1 is the schematic diagram that adopts existing spatial domain correlation method to predict motion loss;

Fig. 2 is the flow chart of existing adopting spatial domain correlation method to predict motion vector;

FIG. 3 is a flow chart of predicting a motion vector provided by an embodiment of the present invention;

FIG. 4 is a schematic diagram of spatial correlation of blocks in a frame provided by an embodiment of the present invention;

FIG. 5 is a schematic diagram of blocks used for motion vector prediction according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of the temporal correlation between a block in a reference frame and a current block provided by an embodiment of the present invention;

Fig. 7 is a structural composition diagram of a motion vector prediction device provided by an embodiment of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Fig. 3 is the flow chart of the prediction motion vector that the embodiment of the present invention provides, as shown in Fig. 3, its specific steps are as follows:

Step 301: sort A to D according to their correlation with Curr from high to low to obtain: B, A, D, C.

Among them, Curr is the current block, A is the left block of Curr, B is the upper block of Curr, C is the upper left block of Curr, and D is the upper right block of Curr.

Figure 4 is a schematic diagram of the spatial domain correlation of the blocks in the frame obtained by using the prior art, as shown in Figure 4, wherein, the previous number in the A, B, C, D blocks is the horizontal component and the motion vector of the block The correlation coefficient of the horizontal component of Curr, and the latter number is the correlation coefficient of the vertical component of the motion vector of the block and the vertical component of Curr. For example: the correlation coefficient between the horizontal component of the motion vector of block A and the horizontal component of Curr is 0.488, and the correlation coefficient between the vertical component of block A and the vertical component of Curr is 0.487. The larger the correlation coefficient, the stronger the correlation. It can be seen that the correlation between A~D and Curr is B, A, D, and C from high to low.

Step 302: Determine whether A, B, and D are all available, if yes, execute step 303; otherwise, execute step 304.

Step 303: The median value of the motion vectors of A, B, and D is used as the predicted motion vector of Curr, and the procedure ends.

The motion vector is composed of a horizontal component and a vertical component, and the median value of the motion vectors of A, B, and D is used as the predicted motion vector of Curr, that is, the median value of the horizontal components of the motion vectors of A, B, and D is used as the motion vector of Curr The horizontal component of , take the median of the vertical components of the motion vectors of A, B, and D as the vertical component of the motion vector of Curr.

For example: the motion vector of A is (a1, a2), the motion vector of B is (b1, b2), and the motion vector of C is (c1, c2), and a1>b1>c1, c2>a2>b2, then Curr The predicted motion vector of is (b1, a2).

Step 304: Determine whether A and B are available, and D is unavailable, if yes, perform step 305; otherwise, perform step 306.

Step 305: The average value of the motion vectors of A and B is used as the predicted motion vector of Curr, and the process ends.

Take the mean value of the motion vectors of A and B as the predicted motion vector of Curr, that is, take the mean value of the horizontal components of the motion vectors of A and B as the horizontal component of the motion vector of Curr, and take the mean value of the vertical components of the motion vectors of A and B As the vertical component of Curr's motion vector.

For example: the motion vector of A is (a1, a2), and the motion vector of B is (b1, b2), then the predicted motion vector of Curr is

Step 306: Determine whether A and B are unavailable, and E and F are available, if yes, perform step 307; otherwise, perform step 310.

Figure 5 shows a schematic diagram of the encoding block used for motion vector prediction in the embodiment of the present invention, as shown in Figure 5, where E is the left block of A and can also be called the second left block of Curr, and F is the upper block of B The block can also be called the upper two blocks of Curr.

Step 307: Determine whether D is available, if yes, execute step 308; otherwise, execute step 309.

Step 308: Use the median value of the motion vectors of E, F, and D as the predicted motion vector of Curr, and the procedure ends.

Step 309: The average value of the motion vectors of E and F is used as the predicted motion vector of Curr, and the process ends.

Step 310: Determine whether one of A and B is available, if yes, go to step 311; otherwise, go to step 312.

Step 311: Use the available motion vector of A or B as the predicted motion vector of Curr, and the process ends.

Step 312: Determine whether A, B, E, F are all unavailable, and D is available, if yes, execute step 313; otherwise, execute step 314.

Step 313: The motion vector of D is used as the predicted motion vector of Curr, and the procedure ends.

Step 314: Determine whether A, B, D, E, F are all unavailable, and G is available, and if so, execute step 315; otherwise, execute step 316.

Fig. 6 is a schematic diagram of the time-domain correlation between the block in the reference frame and the current block Curr obtained by using the prior art. As shown in Fig. 6, M, I, N, H, G, J, L, K, O are Blocks in the reference frame, where the position of block G in the reference frame is the same as that of Curr in the current frame. The first number in each block is the correlation coefficient between the block and Curr. It can be seen that G has the highest correlation with Curr.

Step 315: Use the motion vector of G as the predicted motion vector of Curr, and this process ends.

Step 316: Use the zero vector as the predicted motion vector of Curr.

In practical applications, if only the spatial domain correlation method is used to predict the motion loss, when A, B, D, E, and F are not available, the zero vector is used as the predicted motion vector of Curr.

FIG. 7 is a structural composition diagram of a motion vector prediction device provided by an embodiment of the present invention. As shown in FIG. 7 , it mainly includes: a block motion vector storage module 71 and a motion vector determination module 72, wherein:

Block motion vector storage module 71: store motion vectors of blocks in the current frame.

Motion vector determination module 72: when it is detected that the upper block B and the left block A of the current block Curr are unavailable, and the upper two blocks F and the second left block E of the current block are available, according to the F obtained from the block motion vector storage module 71 , the motion vector of E to determine the predicted motion vector of Curr.

The motion vector determination module 72 may include: a block available detection module 721 and a determination module 722, and the functions of each module are as follows:

Block availability detection module 721 : detect whether the blocks A, B, D, E, F, G are available, and send the detection result to the determination module 722 .

G is the block whose position in the reference frame is the same as that of Curr in the current frame.

Determining module 722: receiving the detection result sent by the block availability detection module 721, if the detection result indicates that A and B are unavailable, E and F are available, and D is available at the same time, then the block D, block obtained from the block motion vector storage module 71, The median value of the motion vectors of E and F is used as the predicted motion vector of Curr; if the detection result indicates that A, B are unavailable, E, F are available, and D is unavailable simultaneously, the block E obtained from the block motion vector storage module 71 , The mean value of the motion vector of F is used as the predicted motion vector of Curr.

In practical applications, the determination module 722 may further include, when the detection result indicates that blocks A, B, and D are all available, taking the median value of the motion vectors of A, B, and D obtained from the block motion vector storage module 71 as Curr's submodule for predicting motion vectors.

In practical applications, the determining module 722 may further include, when the detection result indicates that both blocks A and B are available but D is unavailable, taking the mean value of the motion vectors of A and B obtained from the block motion vector storage module 71 as Curr The submodule for predicting motion vectors.

In practical applications, the determination module 722 may further include, when it is detected that one of the blocks A and B is available, use the available motion vector of A or B acquired from the block motion vector storage module 71 as the predicted motion of Curr Vector of submodules.

In practical applications, the determining module 722 may further include a submodule for using the motion vector of D as the predicted motion vector of Curr when it is detected that blocks A, B, E, and F are not available and D is available.

In practical applications, the determining module 722 may further include, when only the spatial domain correlation method is used to predict the motion vector, if it is detected that the blocks A, B, D, E, and F are not available, the zero vector is used as the prediction of Curr Submodule for motion vectors.

In practical applications, the determination module 722 may further include: when only the space and time domain correlation method is used to predict the motion vector, if it is detected that the blocks A, B, D, E, and F are not available, the block from the block The motion vector of the block G acquired by the motion vector storage module 71 and whose position in the reference frame is the same as that of Curr in the current frame is used as a sub-module of the predictive motion vector of Curr.

It can be seen from the above embodiment that when blocks A and B are not available but blocks E and F are available, the motion vector of Curr can be predicted by blocks E and F instead of blocks A and B, since E is related to A The highest block, F, is the block most correlated with B, and therefore improves the reliability of motion vector prediction. For example: when A, B, and D are not available, the mean value of the motion vectors of E and F can still be used as the predicted motion vector of Curr; and in the prior art, when A, B, and D are not available, the zero vector is directly used As Curr's predicted motion vector, obviously, in this case, the embodiments of the present invention will improve the accuracy of motion vector prediction.

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

Claims (16)

1, a kind of method of motion vector prediction is characterized in that, this method comprises:

When the last piece that detects current block, left piece unavailable, but and last two, the second from left piece time spent of current block determine the motion vectors of current block according to last two of current block, the second from left piece,

Last two of described current block is the last piece of the last piece of current block, and the second from left piece of described current block is the left piece of the left piece of current block.

2, the method for claim 1 is characterized in that, describedly determines that according to last two of current block, the second from left piece the motion vectors of current block comprises:

Whether upper right of judging current block available, if, with last two of current block, the second from left piece, the upper right intermediate value of motion vector as the motion vectors of current block; Otherwise, with last two of current block, the average of the motion vector of the second from left piece motion vectors as current block.

3, the method for claim 1, it is characterized in that, described method further comprises: but when the last piece that detects current block, left piece, upper right time spent all, with the last piece of current block, left piece, the upper right intermediate value of motion vector as the motion vectors of current block.

4, the method for claim 1, it is characterized in that, described method further comprises: when all available and upper right when unavailable of the last piece of current block, left piece, with the average of the motion vector of the last piece of current block, the left piece motion vectors as current block.

5, the method for claim 1 is characterized in that, described method further comprises: but when one of the last piece of current block, the left piece time spent, with the motion vector of available last piece or the left piece motion vectors as current block.

6, the method for claim 1 is characterized in that, described method further comprises: but when the last piece of current block, left piece, last two, all unavailable, a upper right time spent of the second from left piece, with the motion vectors of upper right motion vector as current block.

7, the method for claim 1 is characterized in that, described method further comprises: when the last piece of current block, left piece, upper right, last two, when the second from left piece is all unavailable, with the motion vectors of zero vector as current block.

8, the method for claim 1, it is characterized in that, described method further comprises: when the last piece of current block, left piece, upper right, last two, when the second from left piece is all unavailable, will be in reference frame the motion vector of the present position piece identical with current block present position in present frame as the motion vectors of current block.

9, a kind of motion-vector prediction device is characterized in that, this device comprises:

The block motion vector memory module, the motion vector of the piece in the storage present frame;

The motion vector determination module, when the last piece that detects current block, left piece unavailable, but and last two, the second from left piece time spent of current block, according to last two of the current block that obtains from the block motion vector memory module, the motion vector of the second from left piece, determine the motion vectors of current block, wherein, last two of described current block is the last piece of the last piece of current block, and the second from left piece of described current block is the left piece of the left piece of current block.

10, device as claimed in claim 9 is characterized in that, described motion vector determination module comprises:

The available detection module of piece detects the last piece of current block, left piece, last two, the second from left piece, upper right, whether available, and testing result is sent to determination module;

Determination module, receive described testing result, if the indication of this testing result go up piece, unavailable, last two of left piece, the second from left piece available, simultaneously upper right available, then last two of the current block that will obtain from the block motion vector memory module, the second from left piece, the upper right intermediate value of motion vector are as the motion vectors of current block; If the indication of this testing result go up piece, unavailable, last two of left piece, the second from left piece available, simultaneously upper right unavailable, then last two of the current block that will obtain from the block motion vector memory module, the average of the motion vector of the second from left piece are as the motion vectors of current block.

11, device as claimed in claim 10, it is characterized in that, described determination module further comprises, but be used on testing result indication current block piece, left piece, upper right time spent all, the last piece of the current block that will obtain from the block motion vector memory module, left piece, the upper right intermediate value of motion vector are as the submodule of the motion vectors of current block.

12, device as claimed in claim 10, it is characterized in that, described determination module further comprises, be used on testing result indication current block all available and upper right when unavailable of piece, left piece, the average of the last piece of the current block that will obtain from the block motion vector memory module, the motion vector of left piece is as the submodule of the motion vectors of current block.

13, device as claimed in claim 10, it is characterized in that, described determination module further comprises, but be used for detect current block on one of piece, left piece time spent, the available last piece that will obtain from the block motion vector memory module or the motion vector of left piece are as the submodule of the motion vectors of current block.

14, device as claimed in claim 10, it is characterized in that, described determination module further comprises, but be used for detect current block on piece, left piece, on two, all unavailable, a upper right time spent of the second from left piece, with the submodule of upper right motion vector as the motion vectors of current block.

15, device as claimed in claim 10, it is characterized in that, described determination module further comprises, be used for detect current block on piece, left piece, upper right, on two, when the second from left piece is all unavailable, with the submodule of zero vector as the motion vectors of current block.

16, device as claimed in claim 10, it is characterized in that, described determination module further comprises, be used for detect current block on piece, left piece, upper right, on two, when the second from left piece is all unavailable, will obtain from the block motion vector memory module, reference frame the motion vector of the present position piece identical with current block present position in present frame as the submodule of the motion vectors of current block.

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