WO2012073481A1 - Video-image encoding method and video-image decoding method - Google Patents

Abstract

Provided is a video-image encoding method and a video-image decoding method, wherein a motion vector best suited for the picture to be encoded is derived, and the compression ratio thereof can be improved. A video-image encoding apparatus (100) is provided with: an inter-prediction control unit (109) for determining to execute encoding of a motion vector using a predicted motion-vector candidate that has the least error with respect to a motion vector derived by motion detection, from among a plurality of predicted motion-vector candidates; a picture-type determining unit (110) for generating picture-type information; a time-direct vector calculation unit (111) for deriving a predicted motion-vector candidate using a time-direct mode; and a co-located reference direction determining unit (112) for generating co-located reference direction flags for each of the pictures.

Description

Video encoding method and video decoding method

The present invention relates to a moving image encoding method and a moving image decoding method.

In the moving image encoding process, in general, the amount of information is compressed using redundancy in the spatial direction and temporal direction of a moving image. In general, as a method of using redundancy in the spatial direction, conversion to the frequency domain is used, and as a method of using redundancy in the temporal direction, inter-picture prediction (hereinafter referred to as inter prediction) encoding is used. Processing is used. In the inter prediction encoding process, when a certain picture is encoded, an encoded picture that is ahead or behind in the display time order with respect to the encoding target picture is used as a reference picture. Then, by detecting the motion of the encoding target picture relative to the reference picture, a motion vector is derived, and the difference between the predicted image data obtained by performing motion compensation based on the motion vector and the image data of the encoding target picture is obtained. Thus, redundancy in the time direction is removed. Here, in motion detection, a difference value between a coding target block in a coded picture and a block in a reference picture is calculated, and a block in the reference picture having the smallest difference value is set as a reference block. Then, a motion vector is detected using the encoding target block and the reference block.

, H. already standardized. In a moving picture encoding method called H.264, three types of picture types, i.e., an I picture, a P picture, and a B picture, are used to compress the amount of information. An I picture is a picture that does not perform inter prediction encoding processing, that is, performs intra prediction (hereinafter referred to as intra prediction) encoding processing. A P picture is a picture that is subjected to inter prediction encoding with reference to one already encoded picture in front of or behind the current picture in display time order. The B picture is a picture that performs inter prediction encoding with reference to two already encoded pictures that are in front of or behind the encoding target picture in display time order.

H. In a moving picture coding method called H.264, a coding mode called temporal direct can be selected when a motion vector is derived in coding a B picture. An inter prediction encoding method in temporal direct will be described with reference to FIG. FIG. 1 is an explanatory diagram showing motion vectors in temporal direct, and shows a case where block a of picture B2 is encoded in temporal direct. In this case, the motion vector a used when the block b at the same position as the block a in the picture P3 which is the reference picture behind the picture B2 is encoded is used. The motion vector a is a motion vector used when the block b is encoded, and refers to the picture P1. The block a is encoded by obtaining a reference block from a picture P1 that is a forward reference picture and a picture P3 that is a backward reference picture using a motion vector parallel to the motion vector a, and performing bi-directional prediction. The That is, the motion vector used when coding the block a is the motion vector b for the picture P1 and the motion vector c for the picture P3.

However, in the conventional temporal direct, the motion vector used in the temporal direct is a motion vector of a reference picture behind the current picture in display time order, and forward in the display time order. Limited to motion vectors.

As described above, since the motion vectors used in the time direct are limited, it is difficult to derive the motion vector most suitable for the picture to be encoded, and there is a problem that the compression rate is lowered. .

An object of the present invention is to solve the above-mentioned problem, and by deriving a motion vector most suitable for a picture to be encoded by adaptively selecting a motion vector to be used in temporal directing. Another object is to provide a moving picture encoding method and a moving picture decoding method capable of improving the compression rate.

In order to solve the above-described problem, a moving picture coding method according to the present invention is a moving picture coding method for coding a coding target block included in a coding target picture, and is different from the coding target picture. The motion of the current block is scaled by scaling the reference motion vector of the reference block that is included in the reference picture and whose position in the reference picture is the same as the position of the current block in the current picture. A calculation step for calculating a vector candidate; and a predetermined motion vector is used to encode a block to be encoded, and an error value between the predetermined motion vector and the motion vector candidate and the selected motion vector candidate are identified And an encoding step for encoding the information to be performed.

The moving picture decoding method according to the present invention is a moving picture decoding method for decoding a decoding target block included in a decoding target picture, and is included in a reference picture different from the decoding target picture. In addition, the motion vector candidate of the decoding target block is calculated by scaling the reference motion vector of the reference block whose position in the reference picture is the same as the position of the decoding target block in the decoding target picture. A first decoding step; a first decoding step for decoding error value information between the predetermined motion vector and the motion vector candidate; and adding the motion vector candidate and the error value information to obtain a motion vector And a second decoding step for decoding the block to be decoded using the motion vector. Characterized in that it comprises a flop, a.

The moving picture decoding method according to the present invention is a moving picture decoding method for decoding a decoding target block included in a decoding target picture, and is included in a reference picture different from the decoding target picture. And by scaling the reference motion vector of the reference block whose position in the reference picture is the same as the position of the decoding target block in the decoding target picture, the first motion vector candidate of the decoding target block And a first calculation step for calculating a second motion vector candidate, and a motion vector candidate having a small error from the predetermined motion vector among the first motion vector candidate and the second motion vector candidate. Index setting that makes the corresponding index value larger than the index value corresponding to the other motion vector candidate A first decoding step of decoding index information specifying a motion vector candidate, a first decoding step of decoding error value information between a predetermined motion vector and the motion vector candidate specified by the index information Decoding step, a second calculation step of adding the error value information by adding the motion vector candidate specified by the index information and calculating a motion vector, and using the motion vector, And a second decoding step for decoding.

In addition, the moving picture encoding method according to the present invention encodes the encoding target block using a reference motion vector of a reference block included in a reference picture different from the encoding target picture including the encoding target block. In the image coding method, the position of the reference block in the picture is the same as the position of the block to be coded in the picture to be coded, and the reference block has two or more reference motion vectors. If the reference picture is forward or backward of the encoding target picture, an additional step of adding a predicted motion vector obtained from the reference motion vector to a predicted motion vector candidate based on whether the reference picture is ahead or behind And a prediction motion vector for encoding the motion vector of the target block from the determined prediction motion vector candidates. Using the selected prediction motion vector, the motion vector error of the motion vector of the coding target block is obtained, and the motion vector error and the index of the selected motion vector predictor are encoded. And an encoding step to be performed.

Note that the present invention can be realized not only as such a moving image encoding method and a moving image decoding method, but also including the characteristic steps included in such a moving image encoding method and a moving image decoding method. It can also be realized as a moving picture encoding apparatus and a moving picture decoding apparatus as means, or as a program for causing a computer to execute these steps. Such a program can be realized as a recording medium such as a computer-readable CD-ROM, or can be realized as information, data, or a signal indicating the program. These programs, information, data, and signals may be distributed via a communication network such as the Internet.

According to the present invention, it is possible to derive a motion vector most suitable for a picture to be encoded by adaptively selecting a motion vector to be used in time direct, and to improve a compression rate. Is possible.

FIG. 1 is an explanatory diagram showing motion vectors in time direct. FIG. 2 is a block diagram showing a configuration of an embodiment of a moving picture coding apparatus using the moving picture coding method according to the present invention. FIG. 3 is a flowchart showing an outline of the processing flow of the moving picture encoding method according to the present invention. FIG. 4A is a diagram illustrating an example of a motion vector predictor candidate. FIG. 4B is a diagram illustrating an example of how to assign a predicted motion vector index. FIG. 5 is a diagram illustrating an example of a code table used when the motion vector predictor index is variable length encoded. FIG. 6 is a flowchart showing a flow of determining a motion vector predictor candidate in the inter prediction control unit according to the first embodiment. FIG. 7 is a flowchart showing a detailed processing flow of step S102 of FIG. FIG. 8A is a diagram illustrating an example of a method for deriving predicted motion vector candidates by temporal direct. FIG. 8B is a diagram illustrating an example of a method for deriving predicted motion vector candidates by temporal direct. FIG. 9A is a diagram illustrating an example of a method for deriving predicted motion vector candidates by temporal direct. FIG. 9B is a diagram illustrating an example of a method for deriving predicted motion vector candidates by temporal direct. FIG. 10 is a flowchart showing a detailed processing flow in the second embodiment in step S102 of FIG. FIG. 11A is a diagram illustrating an example of a method for deriving predicted motion vector candidates by temporal direct. FIG. 11B is a diagram illustrating an example of a method for deriving a predicted motion vector candidate by temporal direct. FIG. 12 is a flowchart showing a detailed processing flow in the third embodiment in step S102 of FIG. FIG. 13 is a flowchart showing a detailed processing flow in step S102 and step S103 of FIG. 2 according to the fourth embodiment. FIG. 14 is a flowchart showing a detailed processing flow in the fifth embodiment of step S102 and step S103 of FIG. FIG. 15 is a block diagram showing a configuration of an embodiment of a moving picture decoding apparatus using the moving picture decoding method according to the present invention. FIG. 16 is a flowchart showing an outline of the processing flow of the moving picture decoding method according to the present invention. FIG. 17 is an overall configuration diagram of a content supply system that implements a content distribution service. FIG. 18 is an overall configuration diagram of a digital broadcasting system. FIG. 19 is a block diagram illustrating a configuration example of a television. FIG. 20 is a block diagram illustrating a configuration example of an information reproducing / recording unit that reads and writes information from and on a recording medium that is an optical disk. FIG. 21 is a diagram illustrating a structure example of a recording medium that is an optical disk. FIG. 22A illustrates an example of a mobile phone. FIG. 22B is a block diagram illustrating a configuration example of a mobile phone. FIG. 23 is a diagram showing a structure of multiplexed data. FIG. 24 is a diagram schematically showing how each stream is multiplexed in the multiplexed data. FIG. 25 is a diagram showing in more detail how the video stream is stored in the PES packet sequence. FIG. 26 is a diagram illustrating the structure of TS packets and source packets in multiplexed data. FIG. 27 is a diagram illustrating a data structure of the PMT. FIG. 28 is a diagram illustrating an internal configuration of multiplexed data information. FIG. 29 shows the internal structure of stream attribute information. FIG. 30 shows steps for identifying video data. FIG. 31 is a block diagram illustrating a configuration example of an integrated circuit that realizes the moving picture coding method and the moving picture decoding method according to each embodiment. FIG. 32 is a diagram showing a configuration for switching the drive frequency. FIG. 33 is a diagram showing steps for identifying video data and switching between driving frequencies. FIG. 34 is a diagram showing an example of a look-up table in which video data standards are associated with drive frequencies. FIG. 35A is a diagram illustrating an example of a configuration for sharing a module of a signal processing unit. FIG. 35B is a diagram illustrating another example of a configuration for sharing a module of a signal processing unit.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 2 is a block diagram showing a configuration of an embodiment of a moving picture coding apparatus using the moving picture coding method according to the present invention.

As shown in FIG. 2, the moving image encoding apparatus 100 includes an orthogonal transform unit 101, a quantization unit 102, an inverse quantization unit 103, an inverse orthogonal transform unit 104, a block memory 105, a frame memory 106, an intra prediction unit 107, An inter prediction unit 108, an inter prediction control unit 109, a picture type determination unit 110, a temporal direct vector calculation unit 111, a co-located reference direction determination unit 112, and a variable length coding unit 113 are provided.

The orthogonal transform unit 101 performs transform from the image domain to the frequency domain for the input image sequence. The quantization unit 102 performs a quantization process on the input image sequence converted into the frequency domain. The inverse quantization unit 103 performs inverse quantization processing on the input image sequence quantized by the quantization unit 102. The inverse orthogonal transform unit 104 performs transform from the frequency domain to the image domain for the input image sequence subjected to the inverse quantization process. The block memory 105 stores the input image sequence in units of blocks, and the frame memory 106 stores the input image sequence in units of frames. The picture type determination unit 110 determines which of the I picture, B picture, and P picture is used to encode the input image sequence, and generates picture type information. The intra prediction unit 107 encodes the block to be encoded by intra prediction using the block-unit input image sequence stored in the block memory 105, and generates predicted image data. The inter prediction unit 108 encodes the block to be encoded by inter prediction using the input image in units of frames stored in the frame memory 106 and the motion vector derived by motion detection, and generates predicted image data. . The co-located reference direction determination unit 112 is included in a block (hereinafter referred to as a forward reference block) included in a picture located in front of the encoding target picture in display time order or a picture located in the rear. Which block (hereinafter referred to as a backward reference block) is determined as a co-located block, a co-located reference direction flag is generated for each picture, and is attached to the encoding target picture. Here, the co-located block is a block in a picture different from the picture including the encoding target block, and is a block whose position in the picture is the same as that of the encoding target block. When the co-located block has one motion vector, the temporal direct vector calculation unit 111 uses the motion vector of the co-located block to perform a predicted motion vector candidate (temporal direct vector 1). ) Is derived. In addition, a predicted motion vector index value corresponding to the temporal direct vector 1 is assigned. Then, the temporal direct vector 1 and the motion vector predictor index are sent to the inter prediction control unit 109. When the co-located block has two motion vectors, the temporal direct vector calculation unit 111 uses the respective motion vectors of the co-located block to perform predicted motion vector candidates (temporal direct). Deriving vector 1, time direct vector 2). Also, the motion vector predictor index value corresponding to each of the temporal direct vectors 1 and 2 is assigned. Then, the temporal direct vectors 1 and 2 and the predicted motion vector index corresponding to each are sent to the inter prediction control unit 109. Here, when the co-located block has one motion vector, only the temporal direct vector 1 is derived. However, the present invention is not limited to this configuration. For example, when the motion vector of the co-located block is set to 0, the time direct vector 2 may be derived by time direct. Here, when the motion vector of the co-located block is set to 0, the configuration is not limited to the configuration in which the predicted motion vector candidate is derived by temporal direct, but the temporal direct vector 2 may be derived as 0. When the co-located block does not have a motion vector, the motion vector derivation by the time direct is stopped or the motion vector is set to 0, and the motion vector predictor (temporal direct vector 1) is obtained by the time direct. To derive. When the temporal direct vector 1 is derived, the temporal direct vector 1 and a prediction motion vector index corresponding to the temporal direct vector 1 are sent to the inter prediction control unit 109. Here, when the co-located block has no motion vector, the temporal direct vector 1 may be derived as 0. The inter prediction control unit 109 determines to encode a motion vector using a predicted motion vector candidate having the smallest error from a motion vector derived by motion detection from a plurality of predicted motion vector candidates. Here, the error indicates a difference value between the predicted motion vector candidate and the motion vector derived by motion detection. Also, a predicted motion vector index corresponding to the determined predicted motion vector is generated for each block. Then, the motion vector predictor index and error information of motion vector predictor candidates are sent to the variable length coding unit 113.

The orthogonal transformation unit 101 performs transformation from the image domain to the frequency domain on the prediction error data generated and the prediction error data between the input image sequence. The quantization unit 102 performs a quantization process on the prediction error data converted into the frequency domain. The variable length encoding unit 113 performs variable length encoding processing on the prediction error data, the prediction motion vector index, the prediction error information of the prediction motion vector candidate, the picture type information, and the co-located reference direction flag that have been quantized. By doing so, a bitstream is generated.

FIG. 3 is a flowchart showing an outline of the processing flow of the moving picture encoding method according to the present invention. In step S101, the co-located reference direction determination unit 112 determines which of the forward reference block and the backward reference block is the co-located block when the motion vector predictor candidate is derived in time direct. Also, a co-located reference direction flag indicating whether the co-located block is a forward reference block or a backward reference block is generated for each picture and is attached to the picture. In step S102, the temporal direct vector calculation unit 111 derives a predicted motion vector candidate by temporal direct using the reference motion vector of the co-located block. When the co-located block has one motion vector, a predicted motion vector candidate (temporal direct vector 1) is derived by temporal direct using the motion vector of the co-located block. Then, a motion vector predictor index value corresponding to the temporal direct vector 1 is allocated. When the co-located block has two motion vectors, the temporal direct vector calculation unit 111 uses the respective motion vectors of the co-located block to perform predicted motion vector candidates (temporal direct). Deriving vector 1, time direct vector 2). A motion vector predictor index value corresponding to each of the temporal direct vectors 1 and 2 is assigned. Here, how to allocate the predicted motion vector index is determined by the reference direction of the co-located block. In general, a motion vector predictor index requires less information when the value is small. On the other hand, as the value increases, the amount of information required increases. Therefore, if the value of the predicted motion vector index corresponding to a motion vector that is highly likely to be a more accurate motion vector is decreased, the encoding efficiency is increased. Therefore, when the co-located block is a backward reference block, a motion vector that refers to a picture located before the picture including the co-located block in the order of display time (hereinafter referred to as a forward reference motion vector). ) Is used to assign a small predicted motion vector index to the predicted motion vector candidate (temporal direct vector 1). On the other hand, a predicted motion vector candidate (temporal direct vector 2) derived using a motion vector (hereinafter referred to as a backward reference motion vector) referring to a picture located after the picture including the co-located block in the display time order. ) Is assigned a motion vector predictor index having a value larger than the value for temporal direct vector 1. Since the forward reference motion vector is a vector in the direction in which the coding target picture is located from the picture including the co-located block in the display order, there is a high possibility that a highly accurate predicted motion vector candidate can be derived. Therefore, when the co-located block is a backward reference block, the predicted motion vector index value corresponding to the predicted motion vector candidate derived using the forward reference motion vector is predicted using the backward reference motion vector. By making it smaller than the value of the predicted motion vector index corresponding to the motion vector candidate, the coding efficiency can be improved. On the other hand, when the co-located block is a forward reference block, the predicted motion vector index value corresponding to the predicted motion vector candidate derived using the backward reference motion vector is predicted using the forward reference motion vector. It is made smaller than the value of the predicted motion vector index corresponding to the motion vector candidate. In step S103, the inter prediction control unit 109 encodes a picture by inter prediction using a motion vector derived by motion detection. Also, the inter prediction control unit 109 determines to perform the motion vector encoding from the prediction motion vector candidates using the prediction motion vector with the smallest error. For example, it is determined that a difference value between a predicted motion vector candidate and a motion vector derived by motion detection is an error, and the predicted motion vector candidate having the smallest error is used when encoding a motion vector. Then, the variable length coding unit 113 performs variable length coding on the predicted motion vector index corresponding to the selected predicted motion vector candidate and the error information of the determined predicted motion vector candidate.

FIG. 4A is a diagram illustrating an example of a motion vector predictor candidate. The motion vector A (MV_A) is a motion vector of the adjacent block A located on the left side of the encoding target block. A motion vector B (MV_B) is a motion vector of an adjacent block B located above the encoding target block. The motion vector C (MV_C) is a motion vector of an adjacent block C located on the upper right side of the encoding target block. Median (MV_A, MV_B, MV_C) indicates an intermediate value of the motion vectors A, B, and C. Here, the intermediate value is derived as follows.

FIG. 4B is a diagram illustrating an example of how to assign a predicted motion vector index. The value of the predicted motion vector index is “0” for the value corresponding to Median (MV_A, MV_B, MV_C), “1” for the value corresponding to motion vector A, and “2” for the value corresponding to MV_B, The value corresponding to MV_C is “3”, the value corresponding to temporal direct vector 1 is “4”, and the value corresponding to temporal direct vector 2 is “5”. The method of assigning the motion vector predictor index is not limited to this example.

FIG. 5 is a diagram illustrating an example of a code table used when the motion vector predictor index is variable length encoded. Codes with short code lengths are assigned in ascending order of predicted motion vector index values. Therefore, it is possible to improve the encoding efficiency by reducing the value of the motion vector predictor index corresponding to a motion vector predictor candidate that is likely to have good prediction accuracy.

FIG. 6 is a flowchart showing the determination flow of a motion vector predictor candidate in the inter prediction control unit 109. In step S201, the motion vector predictor candidate index mvp_idx = 0 and the minimum motion vector error = ∞. In step S202, it is determined whether or not the motion vector predictor candidate index mvp_idx is smaller than the number of motion vector predictor candidates. In step S203, when it is determined in step S202 that the predicted motion vector candidate index mvp_idx is smaller than the number of predicted motion vector candidates, a motion vector error is calculated from the difference between the motion vector derived by motion detection and the predicted motion vector candidate. To do. In step S204, it is determined whether or not the motion vector error calculated in step S202 is smaller than the minimum motion vector error. In step S205, if it is determined in step S204 that the motion vector error is smaller than the minimum motion vector error, the minimum motion vector error is set as the calculated motion vector error, and the predicted motion vector index is set as the predicted motion vector candidate index mvp_idx. In step S206, “1” is added to the motion vector predictor candidate index mvp_idx, and the process returns to step S202. In step S207, when it is determined in step S202 that the predicted motion vector candidate index mvp_idx is not smaller than the number of predicted motion vector candidates, the minimum motion vector error and the predicted motion vector index are variable-length encoded. As described above, according to the flow shown in FIG. 6, it is determined that the predicted motion vector candidate having the smallest error from the motion vector derived by the motion detection is used when the motion vector is encoded. Then, the error information of the determined motion vector predictor candidate and the motion vector predictor index indicating the determined motion vector predictor are variable length encoded.

FIG. 7 is a detailed processing flow of step S102 of FIG. Hereinafter, FIG. 7 will be described. In step S301, the temporal direct vector calculation unit 111 determines whether the co-located block has two or more motion vectors, that is, at least a forward reference motion vector (mvL0) and a backward reference motion vector (mvL1). It is determined whether or not it has. In step S302, when it is determined in step S301 that the co-located block has two or more motion vectors, it is determined whether or not the co-located block is a backward reference block. If it is determined in step S302 that the co-located block is a backward reference block, a predicted motion vector candidate (temporal direct vector 1) is derived by temporal direct using the forward reference motion vector in step S303. To do. In step S304, a predicted motion vector candidate (temporal direct vector 2) is derived by temporal direct using the backward reference motion vector. On the other hand, when it is determined in step S302 that the co-located block is a forward reference block, in step S306, a predicted motion vector candidate (temporal direct vector 1) is obtained by temporal direct using the backward reference motion vector. Is derived. In step S307, a predicted motion vector candidate (temporal direct vector 2) is derived by temporal direct using the forward reference motion vector. In step S305, the motion vector predictor index values are assigned in the order of the temporal direct vectors 1 and 2. That is, the value of the motion vector predictor index corresponding to the temporal direct vector 1 is made smaller than the value of the motion vector predictor index corresponding to the temporal direct vector 2. For example, as shown in FIG. 4, the value of the predicted motion vector index corresponding to the temporal direct vector 1 is set to 4, and the value of the predicted motion vector index corresponding to the temporal direct vector 2 is set to 5. In step S308, when it is determined in step S301 that the co-located block has only one of the forward reference motion vector and the backward reference motion vector, the co-located block is moved forward. It is determined whether or not it has a vector. When it is determined in step S308 that the co-located block has the forward reference motion vector, in step S309, the predicted motion vector is temporally direct using the forward reference motion vector of the co-located block. A candidate (temporal direct vector 1) is derived. In step S311, if it is determined in step S308 that the co-located block does not have a forward reference motion vector, it is determined whether or not the co-located block has a backward reference motion vector. . If it is determined in step S311 that the co-located block has a backward reference motion vector, a predicted motion vector candidate (temporal direct vector 1) is derived by temporal direct using the backward reference motion vector. To do. In step S310, a predicted motion vector index value corresponding to the temporal direct vector 1 is assigned. For example, in FIG. 4B, the value of the predicted motion vector index corresponding to the temporal direct vector 1 is “4”, and the predicted motion vector index with the value “5” is not used. If it is determined in step S311 that the co-located block does not have the backward reference motion vector, in step S313, the derivation of the predicted motion vector candidate is stopped by temporal direct, and the temporal direct vector Is not added to the prediction vector candidate. For example, in FIG. 4, the motion vector predictor indexes whose values are “4” and “5” are not used.

In the processing flow of FIG. 7, it is determined whether or not the co-located block has a forward reference motion vector in step S308, and whether or not the co-located block has a backward reference motion vector in step S311. Is not limited to this flow. For example, it may be determined whether or not the co-located block has a backward reference motion vector, and then it may be determined whether or not the co-located block has a forward reference motion vector.

Next, a method for deriving a motion vector by time direct will be described in detail.

FIG. 8A illustrates a case where a co-located block is a backward reference block and includes a forward reference motion vector and a backward reference motion vector, and a predicted motion vector candidate (temporal direct) using temporal reference using the forward reference motion vector. It shows how to derive vector 1). Using the forward reference motion vector, a predicted motion vector candidate (TemporalMV) is derived by the following calculation formula.

(Formula 4) TemporalMV = mvL0 × (B2-B0) / (B4-B0)

Here, (B2-B0) indicates time difference information in the display time of picture B2 and picture B0, and (B4-B0) indicates time difference information in the display time of picture B4 and picture B0.

FIG. 8B shows a method of deriving a predicted motion vector candidate (temporal direct vector 2) by temporal direct using a backward reference motion vector. Using the backward reference motion vector, a predicted motion vector candidate is derived by the following calculation formula.

(Formula 5) TemporalMV = mvL1 × (B2-B0) / (B4-B8)

FIG. 9A shows a case where a co-located block is a forward reference block and has a forward reference motion vector and a backward reference motion vector, and uses a backward reference motion vector to perform a predicted motion vector candidate (temporal direct). It shows how to derive vector 1). Using the backward reference motion vector, a predicted motion vector candidate is derived by the following calculation formula.

(Formula 6) TemporalMV = mvL1 × (B6-B8) / (B4-B8)

FIG. 9B shows a method of deriving a predicted motion vector candidate (temporal direct vector 2) by temporal direct using a forward reference motion vector. Using the backward reference motion vector, a predicted motion vector candidate is derived by the following calculation formula.

(Expression 7) TemporalMV = mvL0 × (B6-B8) / (B4-B0)

Thus, according to the present invention, when a motion vector is encoded, encoding efficiency can be improved by using a predicted motion vector candidate having the smallest error value from a plurality of predicted motion vector candidates. For example, a difference value and an error between a motion vector obtained by motion detection and a predicted motion vector candidate are used. Moreover, since the value of the motion vector predictor index corresponding to the motion vector predictor candidate whose error value is likely to be small is reduced, the coding efficiency can be improved. For example, when the co-located block is a backward reference block, the forward reference motion vector is a vector in the direction in which the encoding target picture is located from the picture including the co-located block in the display order. Therefore, the predicted motion vector candidate calculated using the forward reference motion vector is likely to be a highly accurate motion vector. Therefore, the predicted motion vector index value corresponding to the predicted motion vector candidate derived using the forward reference motion vector is set to be greater than the predicted motion vector index value corresponding to the predicted motion vector candidate derived using the backward reference motion vector. By reducing the encoding efficiency, the encoding efficiency can be improved.

(Embodiment 2)
In the present embodiment, when a co-located block has two or more motion vectors, a motion vector temporally close to a picture including the co-located block (a motion vector with a short temporal distance) The configuration differs from the other embodiments in that the value of the predicted motion vector index corresponding to the predicted motion vector candidate derived using is reduced. Here, the temporal distance is determined according to the number of pictures between the picture including the co-located block and the reference picture referred to by the co-located block in the order of display time.

FIG. 10 is a flowchart showing a detailed processing flow of step S102 of FIG. Hereinafter, FIG. 10 will be described.

In step S401, the temporal direct vector calculation unit 111 determines whether the co-located block has two or more motion vectors, that is, at least a forward reference motion vector (mvL0) and a backward reference motion vector (mvL1). It is determined whether or not it has. In step S402, it is determined whether or not the reference picture referenced by the forward reference motion vector is temporally closer to the picture including the co-located block than the reference picture referenced by the backward reference motion vector. That is, it is determined which of the forward reference motion vector and the backward reference motion vector has a short temporal distance. In step S402, when it is determined that the reference picture referred to by the forward reference motion vector is temporally closer to the picture including the co-located block, in step S403, using the forward reference motion vector, The motion vector predictor candidate (temporal direct vector 1) is derived directly. In step S404, a predicted motion vector candidate (temporal direct vector 2) is derived by temporal direct using the backward reference motion vector. On the other hand, when it is determined in step S402 that the reference picture referred to by the backward reference motion vector is temporally closer to the picture including the co-located block, in step S406, the backward reference motion vector is used. A predicted motion vector candidate (temporal direct vector 1) is derived by temporal direct. In step S407, a predicted motion vector candidate (temporal direct vector 2) is derived by temporal direct using the forward reference motion vector. In step S405, the motion vector predictor index values are assigned in the order of the temporal direct vectors 1 and 2. That is, the value of the motion vector predictor index corresponding to the temporal direct vector 1 is made smaller than the value of the motion vector predictor index corresponding to the temporal direct vector 2. For example, as shown in FIG. 4, the value of the predicted motion vector index corresponding to the temporal direct vector 1 is set to 4, and the value of the predicted motion vector index corresponding to the temporal direct vector 2 is set to 5. In step S408, if it is determined in step S401 that the co-located block has only one of the forward reference motion vector and the backward reference motion vector, the co-located block is forward reference motion. It is determined whether or not it has a vector. When it is determined in step S408 that the co-located block has the forward reference motion vector, in step S409, the predicted motion vector is temporally direct using the forward reference motion vector of the co-located block. A candidate (temporal direct vector 1) is derived. In step S411, if it is determined in step S408 that the co-located block does not have a forward reference motion vector, it is determined whether or not the co-located block has a backward reference motion vector. . If it is determined in step S411 that the co-located block has a backward reference motion vector, a predicted motion vector candidate (temporal direct vector 1) is derived by temporal direct using the backward reference motion vector. To do. In step S410, a predicted motion vector index value corresponding to the temporal direct vector 1 is assigned. For example, in FIG. 4, the value of the predicted motion vector index corresponding to the temporal direct vector 1 is set to 4, and a predicted motion vector index with a value of 5 is not used. If it is determined in step S411 that the co-located block does not have a backward reference motion vector, in step S413, the prediction of motion vector candidates is stopped by temporal direct, and the temporal direct vector Is not added to the prediction vector candidate. For example, in FIG. 4, the motion vector predictor indexes whose values are “4” and “5” are not used.

Next, a method for deriving a motion vector by time direct will be described in detail.

FIG. 11A shows that when a co-located block has a forward reference motion vector and a backward reference motion vector, and the forward reference motion vector is closer in time, the forward reference motion vector is used to perform temporal direct operation. Shows a method of deriving a predicted motion vector candidate (temporal direct vector 1). Using the forward reference motion vector, a predicted motion vector candidate is derived by the following calculation formula.

(Equation 8) TemporalMV = mvL0 × (B2-B0) / (B4-B0)

FIG. 11B shows a method of deriving a predicted motion vector candidate (temporal direct vector 2) by temporal direct using a backward reference motion vector. Using the backward reference motion vector, a predicted motion vector candidate is derived by the following calculation formula.

(Equation 9) TemporalMV = mvL1 × (B2-B0) / (B4-B8)

Thus, according to the present invention, when a motion vector is encoded, encoding efficiency can be improved by using a predicted motion vector candidate having the smallest error value from a plurality of predicted motion vector candidates. For example, a difference value and an error between a motion vector obtained by motion detection and a predicted motion vector candidate are used. In addition, since the motion vector with a short temporal distance, that is, the motion vector predictor index value corresponding to the motion vector predictor candidate that is likely to have a small error value is reduced, the encoding efficiency can be improved. it can.

Note that this embodiment mode can be combined with other embodiment modes. For example, when the determination step S302 of FIG. 7 of the first embodiment is combined with the determination step S402 of FIG. 10 of the second embodiment, the present embodiment is more effective than the determination step S302 of FIG. 7 of the first embodiment. A configuration in which the determination step S402 of FIG. First, a temporal distance between two or more motion vectors is determined, and a motion vector derived by temporal direct is used as a temporal direct vector 1 using a motion vector having a short temporal distance, and the temporal distance is long. A motion vector derived by temporal direct using the motion vector is referred to as temporal direct vector 2. When two or more motion vectors have the same temporal distance, the temporal direct vectors 1 and 2 are selected based on whether the co-located block is a forward reference block or a backward reference block. Since this embodiment has a larger influence on the motion vector, a more optimal motion vector can be selected by giving priority to the size of the motion vector.

(Embodiment 3)
In the present embodiment, when the co-located block has two or more motion vectors, the predicted motion vector index value corresponding to the predicted motion vector candidate derived using the motion vector having a small size is used. The configuration is different from the other embodiments in that the size is reduced. Here, the magnitude of the motion vector means an absolute value of the motion vector.

FIG. 12 is a flowchart showing a detailed processing flow of step S102 of FIG. Hereinafter, FIG. 12 will be described.

In step S501, the temporal direct vector calculation unit 111 determines whether the co-located block has two or more motion vectors, that is, at least a forward reference motion vector (mvL0) and a backward reference motion vector (mvL1). It is determined whether or not it has. In step S502, it is determined whether the size of the forward reference motion vector is smaller than the size of the backward reference motion vector. If it is determined in step S502 that the size of the forward reference motion vector is smaller, in step S503, a predicted motion vector candidate (temporal direct vector 1) is obtained by temporal direct using the forward reference motion vector. To derive. In step S504, a predicted motion vector candidate (temporal direct vector 2) is derived by temporal direct using the backward reference motion vector. On the other hand, if it is determined in step S502 that the size of the backward reference motion vector is smaller, in step S506, the backward reference motion vector is used to perform the prediction motion vector candidate (temporal direct vector 1) using temporal direct. Is derived. In step S507, a predicted motion vector candidate (temporal direct vector 2) is derived by temporal direct using the forward reference motion vector. In step S505, the motion vector predictor index values are assigned in the order of the temporal direct vectors 1 and 2. That is, the value of the motion vector predictor index corresponding to the temporal direct vector 1 is made smaller than the value of the motion vector predictor index corresponding to the temporal direct vector 2. For example, as shown in FIG. 4, the value of the predicted motion vector index corresponding to the temporal direct vector 1 is set to 4, and the value of the predicted motion vector index corresponding to the temporal direct vector 2 is set to 5. In step S508, if it is determined in step S501 that the co-located block has only one of the forward reference motion vector and the backward reference motion vector, the co-located block is moved forward. It is determined whether or not it has a vector. When it is determined in step S508 that the co-located block has the forward reference motion vector, in step S509, the predicted motion vector is temporally direct using the forward reference motion vector of the co-located block. A candidate (temporal direct vector 1) is derived. In step S511, if it is determined in step S508 that the co-located block does not have a forward reference motion vector, it is determined whether or not the co-located block has a backward reference motion vector. . If it is determined in step S511 that the co-located block has a backward reference motion vector, a predicted motion vector candidate (temporal direct vector 1) is derived by temporal direct using the backward reference motion vector. To do. In step S510, a motion vector predictor index value corresponding to the temporal direct vector 1 is assigned. For example, in FIG. 4, the value of the predicted motion vector index corresponding to the temporal direct vector 1 is set to 4, and a predicted motion vector index with a value of 5 is not used. If it is determined in step S511 that the co-located block does not have the backward reference motion vector, in step S513, the prediction motion vector candidate is not derived by temporal direct, and the temporal direct vector Is not added to the prediction vector candidate. For example, in FIG. 4, the motion vector predictor indexes whose values are “4” and “5” are not used.

Thus, according to the present invention, when a motion vector is encoded, encoding efficiency can be improved by using a predicted motion vector candidate having the smallest error value from a plurality of predicted motion vector candidates. For example, a difference value and an error between a motion vector obtained by motion detection and a predicted motion vector candidate are used. In addition, since the motion vector having a small size, that is, the motion vector predictor index value corresponding to the motion vector predictor candidate that is likely to have a small error value is reduced, the encoding efficiency can be improved.

Note that this embodiment mode can be combined with other embodiment modes. For example, when the determination step S302 of FIG. 7 according to the first embodiment is combined with the determination step S502 of FIG. 12 according to the third embodiment, the present embodiment is more effective than the determination step S302 of FIG. A configuration in which the determination step S502 of FIG. First, the size of two or more motion vectors is determined, a motion vector derived by temporal direct using a small motion vector is set as temporal direct vector 1, and a motion vector having a large size is used. A motion vector derived by temporal direct is referred to as temporal direct vector 2. When the magnitudes of two or more motion vectors are equal, temporal direct vectors 1 and 2 are selected based on whether the co-located block is a forward reference block or a backward reference block. Since this embodiment has a larger influence on the motion vector, a more optimal motion vector can be selected by giving priority to the size of the motion vector.

(Embodiment 4)
In the present embodiment, a case where a co-located block does not have a motion vector and a motion vector predictor cannot be derived by time direct, or a case where the motion vector becomes 0 will be described.

First, in step S101 of FIG. 3, the co-located reference direction determination unit 112 determines whether the forward reference block is a co-located block or the backward reference block is a co-located block. When the forward reference block is a co-located block, the co-located backward reference priority flag is set to 0. On the other hand, when the backward reference block is a co-located block, the co-located backward reference priority flag is set to 1. The generated co-located backward reference priority flag is generated for each picture and attached to the encoded picture.

Since the co-located block backward reference priority flag is generated on a picture-by-picture basis, the co-located block corresponding to a certain block in the encoding target picture has both the forward reference motion vector and the backward reference motion vector. There may be cases where it is not. In this case, FIG. 13 shows a method for deriving a more appropriate motion vector. FIG. 13 is a flowchart showing a detailed processing flow of steps S102 and S103 of FIG. Hereinafter, a description will be given with reference to FIG.

In step S601, the temporal direct vector calculation unit 111 determines whether or not the co-located backward reference priority flag is 1, that is, whether or not priority is given to the backward reference block. When the co-located backward reference priority flag is 1, in step S602, a motion vector predictor candidate is derived by temporal direct using the motion vector of the co-located block that is the backward reference block. The derived motion vectors are referred to as temporal direct vectors 1 and 2. Here, which of the motion vector derived using the forward reference motion vector and the motion vector derived using the backward reference motion vector is the temporal direct vector 1 or 2 depends on which of the first, second, and third embodiments. Follow the method. In step S603, it is determined in step S602 whether a motion vector predictor candidate has not been derived or whether the value of the motion vector predictor candidate is zero. If a motion vector predictor candidate has not been derived, in step S604, a motion vector predictor candidate is derived by temporal direct using the forward reference block as a co-located block. Then, the derived motion vector predictor candidates are set as temporal direct vectors 1 and 2. Here, the selection of the time direct vectors 1 and 2 follows the method of any one of the first, second and third embodiments. In step S606, when the co-located backward reference priority flag is 0 in step S601, a motion vector predictor candidate is derived by temporal direct using the co-located block that is the forward reference block. Then, the derived motion vector predictor candidates are set as temporal direct vectors 1 and 2. Here, the selection of the time direct vectors 1 and 2 follows the method of any one of the first, second and third embodiments. In step S607, it is determined in step S606 whether a motion vector predictor candidate has not been derived or whether the motion vector predictor candidate is 0. If a motion vector predictor candidate has not been derived, in step S608, a motion vector predictor candidate is derived by temporal direct using the backward reference block as a co-located block. Then, the derived motion vector predictor candidates are set as temporal direct vectors 1 and 2. Here, the selection of the time direct vectors 1 and 2 follows the method of any one of the first, second and third embodiments. Finally, in step S605, it is determined that the motion vector is to be encoded from the plurality of motion vector predictor candidates using the motion vector predictor having the smallest error. For example, it is determined that a difference value between a predicted motion vector candidate and a motion vector derived by motion detection is an error, and the predicted motion vector candidate having the smallest error is used when encoding a motion vector. In addition, a picture is encoded by inter prediction using a motion vector derived by motion detection. Then, the prediction motion vector index corresponding to the selected prediction motion vector candidate and the error information of the determined prediction motion vector candidate are variable-length encoded.

Thus, according to the present invention, when a co-located block does not have a motion vector, it is possible to derive a predicted motion vector candidate by making a block of another picture a co-located block. ing. For example, if the backward reference block is a co-located block, and the co-located block does not have a motion vector, the forward reference block can be a co-located block, thereby enabling prediction motion vector candidates to be derived. ing. Thereby, it is possible to derive a motion vector with higher accuracy.

Note that this example can be combined with other embodiments. For example, instead of step S309 in FIG. 7, a determination step for determining whether or not the co-located block is a backward reference block is provided, and when the co-located block is a backward reference block, the present embodiment When the process of step S604 of FIG. 13 is performed and the co-located reference direction is the forward reference block, the process of step S608 of FIG. Can be derived. Similarly, step S409 in FIG. 10 and step S509 in FIG. 12 are also provided with a determination step for determining whether or not the co-located reference direction is backward, and when the co-located reference direction is backward, If the process of step S604 of FIG. 13 of the present embodiment is performed and the co-located reference direction is forward, the process of step S608 of FIG. It is possible to derive a motion vector.

When the newly selected co-located block has two or more motion vectors, the motion vector is derived by the method described in the first, second, and third embodiments. This makes it possible to derive a motion vector with higher accuracy.

(Embodiment 5)
In the present embodiment, two predicted motion vector candidates are derived by temporal direct using the forward reference motion vector of the co-located block and the backward reference motion vector, with the forward reference block as a co-located block ( Time direct vectors 1, 2). Furthermore, using a backward reference block as a co-located block, two predicted motion vector candidates are derived by temporal direct using the forward reference motion vector and backward reference motion vector of the co-located block (temporal direct vector 3). 4). Then, the motion vector having the smallest prediction error among the predicted motion vector candidates (temporal direct vectors 1, 2, 3, 4) is determined as the motion vector used for inter prediction.

This embodiment will be described with reference to FIGS.

First, a description will be given with reference to FIG. In step S101 of FIG. 3, the co-located reference direction determination unit 112 determines whether the forward reference block is a co-located block or the backward reference block is a co-located block. When the forward reference block is a co-located block, the co-located backward reference priority flag is set to 0. On the other hand, when the backward reference block is a co-located block, the co-located backward reference priority flag is set to 1. The generated co-located backward reference priority flag is generated for each picture and attached to the encoded picture.

Next, a description will be given with reference to FIG. FIG. 14 is a flowchart showing a detailed processing flow of steps S102 and S103 of FIG. In step S701 of FIG. 14, the temporal direct vector calculation unit 111 determines whether or not the co-located backward reference priority flag is 1, that is, whether or not the backward reference block is prioritized. When the co-located backward reference priority flag is 1, in step S702, a motion vector predictor candidate is derived by temporal direct using the motion vector of the co-located block that is the backward reference block. The derived motion vectors are referred to as temporal direct vectors 1 and 2. Here, which of the motion vector derived using the forward reference motion vector and the motion vector derived using the backward reference motion vector is the temporal direct vector 1 or 2 depends on which of the first, second, and third embodiments. Follow the method. In step S703, a motion vector predictor candidate is derived by temporal direct using the forward reference block as a co-located block. Then, the derived motion vectors are set as temporal direct vectors 3 and 4. Here, the selection of the time direct vectors 3 and 4 follows the method of any one of the first, second, and third embodiments. In step S706, when the co-located backward reference priority flag is 0 in step S701, a motion vector predictor candidate is derived by temporal direct using the co-located block that is the forward reference block. The derived motion vectors are referred to as temporal direct vectors 1 and 2. Here, the selection of the time direct vectors 1 and 2 follows the method of any one of the first, second and third embodiments. In step S707, a motion vector predictor candidate is derived by temporal direct using the backward reference block as a co-located block. Then, the derived motion vectors are set as temporal direct vectors 3 and 4. Here, the selection of the time direct vectors 3 and 4 follows the method of any one of the first, second, and third embodiments. Finally, in step S705, it is determined that the motion vector is to be encoded using the predicted motion vector having the smallest error from the plurality of predicted motion vector candidates (temporal direct vectors 1, 2, 3, 4). For example, it is determined that a difference value between a predicted motion vector candidate and a motion vector derived by motion detection is an error, and the predicted motion vector candidate having the smallest error is used when encoding a motion vector. In addition, a picture is encoded by inter prediction using a motion vector derived by motion detection. Then, the prediction motion vector index corresponding to the selected prediction motion vector candidate and the error information of the determined prediction motion vector candidate are variable-length encoded.

Thus, according to the present invention, motion vectors (temporal direct vectors 1, 2, 3) derived for each of the case where the backward reference block is a co-located block and the case where the forward reference block is a co-located block. 4) is a motion vector predictor candidate. Therefore, it is possible to derive a motion vector with higher accuracy. For example, even when the backward reference priority flag is 1, a motion vector with higher accuracy may be derived if the forward reference block is a co-located block. In such a case, in the present embodiment, motion vectors (temporal direct vectors 1, 2) derived for the case where the backward reference block is a co-located block and the case where the forward reference block is a co-located block are used. 3, 4) are the predicted motion vector candidates, so that the most accurate motion vector can be derived.

(Embodiment 6)
FIG. 15 is a block diagram showing a configuration of an embodiment of a moving picture decoding apparatus using the moving picture decoding method according to the present invention.

In this embodiment, a block included in a picture located in front of the decoding target picture in display time order is referred to as a forward reference block. Also, a block included in a picture located behind the decoding target picture in display time order is referred to as a backward reference block.

As illustrated in FIG. 15, the moving image decoding apparatus 200 includes a variable length decoding unit 201, an inverse quantization unit 202, an inverse orthogonal transform unit 203, a block memory 204, a frame memory 205, an intra prediction unit 206, and an inter prediction unit. 207, an inter prediction control unit 208, and a temporal direct vector calculation unit 209.

The variable-length decoding unit 201 performs variable-length decoding processing on the input bitstream, and the bitstream subjected to picture type information, predicted motion vector index, co-located reference direction flag, and variable-length decoding processing Is generated. The inverse quantization unit 202 performs inverse quantization processing on the bitstream that has been subjected to variable length decoding processing. The inverse orthogonal transform unit 203 transforms the bit stream that has been subjected to the inverse quantization process from the frequency domain to the image domain to generate prediction error image data. The block memory stores prediction error image data and an image sequence generated by adding the prediction image data in units of blocks, and the frame memory stores the image sequence in units of frames. The intra prediction unit 206 generates prediction error image data of the decoding target block by performing intra prediction using the block-by-block image sequence stored in the block memory. The inter prediction unit 207 generates prediction error image data of a decoding target block by performing inter prediction using an image sequence in units of frames stored in the frame memory. When the co-located block has one motion vector, the temporal direct vector calculation unit 209 uses the motion vector of the co-located block to perform the predicted motion vector candidate (temporal direct vector 1) using the temporal direct. ) Is derived. Then, the temporal direct vector 1 is sent to the inter prediction control unit 208. When the co-located block has two motion vectors, the temporal direct vector calculation unit 209 uses the motion vectors of the co-located block to perform predicted motion vector candidates (temporal direct). Deriving vector 1, time direct vector 2). Then, the temporal direct vectors 1 and 2 are sent to the inter prediction control unit 208. The method for selecting the time direct vector 1 and the time direct vector 2 follows the first, second, third, and fourth embodiments. Here, when the co-located block has one motion vector, only the temporal direct vector 1 is derived. However, the present invention is not limited to this configuration. For example, when the motion vector of the co-located block is set to 0, a predicted motion vector candidate (temporal direct vector 2) may be derived by temporal direct. Here, when the motion vector of the co-located block is set to 0, the prediction motion vector candidate (temporal direct vector 2) may be derived as 0 without being limited to the configuration in which the prediction motion vector candidate is derived by temporal direct. Good. If the co-located block does not have a motion vector, the derivation of the predicted motion vector candidate by temporal direct is stopped, or the motion vector is set to 0 and the predicted motion vector candidate (temporal direct vector) is 1) is derived. When the temporal direct vector 1 is derived, the temporal direct vector 1 is sent to the inter prediction control unit 208. Here, when the co-located block has no motion vector, the motion vector predictor candidate may be derived as 0. The inter prediction control unit 208 determines a motion vector to be used for inter prediction based on a prediction motion vector index from a plurality of prediction motion vector candidates. Also, the motion vector used in the inter prediction is obtained by adding the prediction error information of the motion vector predictor candidate to the determined vector motion vector predictor value.

Finally, a decoded image sequence is generated by adding the decoded predicted image data and prediction error image data.

FIG. 16 is a flowchart showing an outline of the processing flow of the moving picture decoding method according to the present invention. In step S801, the variable length decoding unit 201 decodes the co-located reference direction flag in units of pictures. In step S802, when the co-located reference direction flag indicates that the co-located block is a backward reference block, the temporal direct vector calculation unit 209 calculates the motion vector derived using the forward reference motion vector. Is a temporal direct vector 1, and a motion vector derived using a backward reference motion vector is a temporal direct vector 2. On the other hand, when the co-located reference direction flag indicates that the co-located block is the forward reference block, the motion vector derived using the backward reference motion vector is set as the temporal direct vector 1, and the backward reference motion is determined. A motion vector derived using a vector is referred to as a temporal direct vector 2. In step S803, the inter prediction control unit 208 determines a motion vector to be used for inter prediction based on the predicted motion vector index from the plurality of predicted motion vector candidates. In addition, prediction error information is added to the determined prediction motion vector candidate to derive a motion vector. Decoding is performed by inter prediction using the derived motion vector.

Note that when the reference block has two or more reference motion vectors, the selection method of the temporal direct vectors 1 and 2 is not limited to the case based on the co-located reference direction flag. For example, the temporal distance of the reference motion vector is calculated, and the motion vector derived using the reference motion vector having a short temporal distance is set as the temporal direct vector 1, and derived using the reference motion vector having a long temporal distance. The motion vector thus obtained may be used as the temporal direct vector 2. Here, the temporal distance is calculated based on the number of pictures between the reference picture including the reference block and the picture referenced by the reference picture at the display time.

Further, for example, the size of the reference motion vector is calculated, the motion vector derived using the reference motion vector having a small size is set as the temporal direct vector 1, and the motion vector derived using the reference motion vector having a large size is calculated. The time direct vector 2 may be used.

If the co-located block does not have a reference motion vector, a new reference picture block is set as a co-located block, and a motion vector is derived. For example, when the reference picture including the co-located block is behind in the display order from the decoding target picture, the co-located block included in the reference picture ahead in the display order from the decoding target picture Select. In addition, when the reference picture including the co-located block is ahead in the display order from the decoding target picture, the co-located block included in the reference picture behind the decoding target picture in the display order Select. In this way, when the co-located block does not have a reference motion vector, a motion vector with higher accuracy is derived by selecting a block included in the reference picture as a new picture as a co-located block. It becomes possible. If the newly selected co-located block has two or more reference motion vectors, whether the co-located block is a forward reference block or a backward reference block, as described above. No, or more accurate by selecting the temporal direct vectors 1 and 2 based on the temporal distance of the reference motion vector of the co-located block or the size of the reference motion vector of the co-located block It is possible to derive a high motion vector.

In addition, when the co-located block is a backward reference block, a motion vector is derived by temporal direct for each of the cases where it is a forward reference block, and predicted motion vector candidates (temporal direct vectors 1, 2, 3, 4) It is good. The method for selecting the time direct vectors 1, 2, 3, 4 follows the fifth embodiment.

As described above, according to the present invention, when a co-located block has two or more motion vectors, it is possible to select an optimal motion vector for the block to be decoded. It is possible to appropriately decode the bitstream.

(Embodiment 7)
By recording a program for realizing the configuration of the moving image encoding method (image encoding method) or the moving image decoding method (image decoding method) shown in each of the above embodiments on a storage medium, each of the above embodiments It is possible to easily execute the processing shown in the form in the independent computer system. The storage medium may be any medium that can record a program, such as a magnetic disk, an optical disk, a magneto-optical disk, an IC card, and a semiconductor memory.

Furthermore, application examples of the moving picture coding method (picture coding method) and the moving picture decoding method (picture decoding method) shown in the above embodiments and a system using the same will be described. The system has an image encoding / decoding device including an image encoding device using an image encoding method and an image decoding device using an image decoding method. Other configurations in the system can be appropriately changed according to circumstances.

FIG. 17 is a diagram showing an overall configuration of a content supply system ex100 that realizes a content distribution service. A communication service providing area is divided into desired sizes, and base stations ex106, ex107, ex108, ex109, and ex110, which are fixed wireless stations, are installed in each cell.

This content supply system ex100 includes a computer ex111, a PDA (Personal Digital Assistant) ex112, a camera ex113, a mobile phone ex114, a game machine ex115 via the Internet ex101, the Internet service provider ex102, the telephone network ex104, and the base stations ex106 to ex110. Etc. are connected.

However, the content supply system ex100 is not limited to the configuration shown in FIG. 17, and may be connected by combining any one of the elements. In addition, each device may be directly connected to the telephone network ex104 without going from the base station ex106, which is a fixed wireless station, to ex110. In addition, the devices may be directly connected to each other via short-range wireless or the like.

The camera ex113 is a device that can shoot moving images such as a digital video camera, and the camera ex116 is a device that can shoot still images and movies such as a digital camera. The mobile phone ex114 is a GSM (registered trademark, Global System for Mobile Communications) system, a CDMA (Code Division Multiple Access) system, a W-CDMA (Wideband-Code Division Multiple Access) system, or an LTE (Long Terminal Evolution) system. HSPA (High-Speed-Packet-Access) mobile phone, PHS (Personal-Handyphone-System), etc.

In the content supply system ex100, the camera ex113 and the like are connected to the streaming server ex103 through the base station ex109 and the telephone network ex104, thereby enabling live distribution and the like. In live distribution, the content (for example, music live video) captured by the user using the camera ex113 is encoded as described in the above embodiments (that is, the image encoding of the present invention). Function as a device) and transmit to the streaming server ex103. On the other hand, the streaming server ex103 stream-distributes the content data transmitted to the requested client. Examples of the client include a computer ex111, a PDA ex112, a camera ex113, a mobile phone ex114, and a game machine ex115 that can decode the encoded data. Each device that receives the distributed data decodes the received data and reproduces it (that is, functions as the image decoding device of the present invention).

Note that the captured data may be encoded by the camera ex113, the streaming server ex103 that performs data transmission processing, or may be shared with each other. Similarly, the decryption processing of the distributed data may be performed by the client, the streaming server ex103, or may be performed in common with each other. In addition to the camera ex113, still images and / or moving image data captured by the camera ex116 may be transmitted to the streaming server ex103 via the computer ex111. The encoding process in this case may be performed by any of the camera ex116, the computer ex111, and the streaming server ex103, or may be performed in a shared manner.

Further, these encoding / decoding processes are generally performed in the computer ex111 and the LSI ex500 included in each device. The LSI ex500 may be configured as a single chip or a plurality of chips. It should be noted that moving image encoding / decoding software is incorporated into some recording medium (CD-ROM, flexible disk, hard disk, etc.) that can be read by the computer ex111, etc., and encoding / decoding processing is performed using the software. May be. Furthermore, when the mobile phone ex114 is equipped with a camera, moving image data acquired by the camera may be transmitted. The moving image data at this time is data encoded by the LSI ex500 included in the mobile phone ex114.

Further, the streaming server ex103 may be a plurality of servers or a plurality of computers, and may process, record, and distribute data in a distributed manner.

As described above, in the content supply system ex100, the encoded data can be received and reproduced by the client. Thus, in the content supply system ex100, the information transmitted by the user can be received, decrypted and reproduced by the client in real time, and personal broadcasting can be realized even for a user who does not have special rights or facilities.

In addition to the example of the content supply system ex100, as shown in FIG. 18, the digital broadcast system ex200 also includes at least the video encoding device (video encoding device) or video decoding of each of the above embodiments. Any of the devices (image decoding devices) can be incorporated. Specifically, in the broadcast station ex201, multiplexed data obtained by multiplexing music data and the like on video data is transmitted to a communication or satellite ex202 via radio waves. This video data is data encoded by the moving image encoding method described in the above embodiments (that is, data encoded by the image encoding apparatus of the present invention). Receiving this, the broadcasting satellite ex202 transmits a radio wave for broadcasting, and this radio wave is received by a home antenna ex204 capable of receiving satellite broadcasting. The received multiplexed data is decoded and reproduced by an apparatus such as the television (receiver) ex300 or the set top box (STB) ex217 (that is, functions as the image decoding apparatus of the present invention).

Also, a reader / recorder ex218 that reads and decodes multiplexed data recorded on a recording medium ex215 such as a DVD or a BD, or encodes a video signal on the recording medium ex215 and, in some cases, multiplexes and writes it with a music signal. It is possible to mount the moving picture decoding apparatus or moving picture encoding apparatus described in the above embodiments. In this case, the reproduced video signal is displayed on the monitor ex219, and the video signal can be reproduced in another device or system using the recording medium ex215 on which the multiplexed data is recorded. Alternatively, a moving picture decoding apparatus may be mounted in a set-top box ex217 connected to a cable ex203 for cable television or an antenna ex204 for satellite / terrestrial broadcasting and displayed on the monitor ex219 of the television. At this time, the moving picture decoding apparatus may be incorporated in the television instead of the set top box.

FIG. 19 is a diagram illustrating a television (receiver) ex300 that uses the video decoding method and the video encoding method described in each of the above embodiments. The television ex300 obtains or outputs multiplexed data in which audio data is multiplexed with video data via the antenna ex204 or the cable ex203 that receives the broadcast, and demodulates the received multiplexed data. Alternatively, the modulation / demodulation unit ex302 that modulates multiplexed data to be transmitted to the outside, and the demodulated multiplexed data is separated into video data and audio data, or the video data and audio data encoded by the signal processing unit ex306 Is provided with a multiplexing / demultiplexing unit ex303.

Further, the television ex300 decodes each of the audio data and the video data, or encodes the respective information, the audio signal processing unit ex304, the video signal processing unit ex305 (function as the image encoding device or the image decoding device of the present invention). ), A speaker ex307 for outputting the decoded audio signal, and an output unit ex309 having a display unit ex308 such as a display for displaying the decoded video signal. Furthermore, the television ex300 includes an interface unit ex317 including an operation input unit ex312 that receives an input of a user operation. Furthermore, the television ex300 includes a control unit ex310 that performs overall control of each unit, and a power supply circuit unit ex311 that supplies power to each unit. In addition to the operation input unit ex312, the interface unit ex317 includes a bridge unit ex313 connected to an external device such as a reader / recorder ex218, a recording unit ex216 such as an SD card, and an external recording unit such as a hard disk. A driver ex315 for connecting to a medium, a modem ex316 for connecting to a telephone network, and the like may be included. Note that the recording medium ex216 is capable of electrically recording information by using a nonvolatile / volatile semiconductor memory element to be stored. Each part of the television ex300 is connected to each other via a synchronous bus.

First, a configuration in which the television ex300 decodes and reproduces multiplexed data acquired from the outside by the antenna ex204 and the like will be described. The television ex300 receives a user operation from the remote controller ex220 or the like, and demultiplexes the multiplexed data demodulated by the modulation / demodulation unit ex302 by the multiplexing / demultiplexing unit ex303 based on the control of the control unit ex310 having a CPU or the like. Furthermore, in the television ex300, the separated audio data is decoded by the audio signal processing unit ex304, and the separated video data is decoded by the video signal processing unit ex305 using the decoding method described in each of the above embodiments. The decoded audio signal and video signal are output from the output unit ex309 to the outside. At the time of output, these signals may be temporarily stored in the buffers ex318, ex319, etc. so that the audio signal and the video signal are reproduced in synchronization. Also, the television ex300 may read multiplexed data from recording media ex215 and ex216 such as a magnetic / optical disk and an SD card, not from broadcasting. Next, a configuration in which the television ex300 encodes an audio signal or a video signal and transmits the signal to the outside or to a recording medium will be described. The television ex300 receives a user operation from the remote controller ex220 and the like, encodes an audio signal with the audio signal processing unit ex304, and converts the video signal with the video signal processing unit ex305 based on the control of the control unit ex310. Encoding is performed using the encoding method described in (1). The encoded audio signal and video signal are multiplexed by the multiplexing / demultiplexing unit ex303 and output to the outside. When multiplexing, these signals may be temporarily stored in the buffers ex320, ex321, etc. so that the audio signal and the video signal are synchronized. Note that a plurality of buffers ex318, ex319, ex320, and ex321 may be provided as illustrated, or one or more buffers may be shared. Further, in addition to the illustrated example, data may be stored in the buffer as a buffer material that prevents system overflow and underflow, for example, between the modulation / demodulation unit ex302 and the multiplexing / demultiplexing unit ex303.

In addition to acquiring audio data and video data from broadcasts, recording media, and the like, the television ex300 has a configuration for receiving AV input of a microphone and a camera, and performs encoding processing on the data acquired from them. Also good. Here, the television ex300 has been described as a configuration capable of the above-described encoding processing, multiplexing, and external output, but these processing cannot be performed, and only the above-described reception, decoding processing, and external output are possible. It may be a configuration.

In addition, when reading or writing multiplexed data from a recording medium by the reader / recorder ex218, the decoding process or the encoding process may be performed by either the television ex300 or the reader / recorder ex218, The reader / recorder ex218 may share with each other.

As an example, FIG. 20 shows a configuration of the information reproducing / recording unit ex400 when data is read from or written to an optical disk. The information reproducing / recording unit ex400 includes elements ex401, ex402, ex403, ex404, ex405, ex406, and ex407 described below. The optical head ex401 irradiates a laser spot on the recording surface of the recording medium ex215 that is an optical disk to write information, and detects reflected light from the recording surface of the recording medium ex215 to read the information. The modulation recording unit ex402 electrically drives a semiconductor laser built in the optical head ex401 and modulates the laser beam according to the recording data. The reproduction demodulator ex403 amplifies the reproduction signal obtained by electrically detecting the reflected light from the recording surface by the photodetector built in the optical head ex401, separates and demodulates the signal component recorded on the recording medium ex215, and is necessary To play back information. The buffer ex404 temporarily holds information to be recorded on the recording medium ex215 and information reproduced from the recording medium ex215. The disk motor ex405 rotates the recording medium ex215. The servo controller ex406 moves the optical head ex401 to a predetermined information track while controlling the rotational drive of the disk motor ex405, and performs a laser spot tracking process. The system control unit ex407 controls the entire information reproduction / recording unit ex400. In the reading and writing processes described above, the system control unit ex407 uses various kinds of information held in the buffer ex404, and generates and adds new information as necessary, and the modulation recording unit ex402, the reproduction demodulation unit This is realized by recording / reproducing information through the optical head ex401 while operating the ex403 and the servo control unit ex406 in a coordinated manner. The system control unit ex407 is composed of, for example, a microprocessor, and executes these processes by executing a read / write program.

In the above, the optical head ex401 has been described as irradiating a laser spot. However, a configuration in which higher-density recording is performed using near-field light may be used.

FIG. 21 shows a schematic diagram of a recording medium ex215 that is an optical disk. Guide grooves (grooves) are formed in a spiral shape on the recording surface of the recording medium ex215, and address information indicating the absolute position on the disc is recorded in advance on the information track ex230 by changing the shape of the groove. This address information includes information for specifying the position of the recording block ex231 that is a unit for recording data, and the recording block is specified by reproducing the information track ex230 and reading the address information in a recording or reproducing apparatus. Can do. Further, the recording medium ex215 includes a data recording area ex233, an inner peripheral area ex232, and an outer peripheral area ex234. The area used for recording user data is the data recording area ex233, and the inner circumference area ex232 and the outer circumference area ex234 arranged on the inner or outer circumference of the data recording area ex233 are used for specific purposes other than user data recording. Used. The information reproducing / recording unit ex400 reads / writes encoded audio data, video data, or multiplexed data obtained by multiplexing these data with respect to the data recording area ex233 of the recording medium ex215.

In the above description, an optical disk such as a single-layer DVD or BD has been described as an example. However, the present invention is not limited to these, and an optical disk having a multilayer structure and capable of recording other than the surface may be used. Also, an optical disc with a multi-dimensional recording / reproducing structure, such as recording information using light of different wavelengths in the same place on the disc, or recording different layers of information from various angles. It may be.

Also, in the digital broadcasting system ex200, the car ex210 having the antenna ex205 can receive data from the satellite ex202 and the like, and the moving image can be reproduced on a display device such as the car navigation ex211 that the car ex210 has. The configuration of the car navigation ex211 may be, for example, a configuration in which a GPS receiving unit is added in the configuration shown in FIG.

FIG. 22A is a diagram showing the mobile phone ex114 using the moving picture decoding method and the moving picture encoding method described in the above embodiment. The mobile phone ex114 includes an antenna ex350 for transmitting and receiving radio waves to and from the base station ex110, a camera unit ex365 capable of capturing video and still images, a video captured by the camera unit ex365, a video received by the antenna ex350, and the like Is provided with a display unit ex358 such as a liquid crystal display for displaying the decrypted data. The mobile phone ex114 further includes a main body unit having an operation key unit ex366, an audio output unit ex357 such as a speaker for outputting audio, an audio input unit ex356 such as a microphone for inputting audio, a captured video, In the memory unit ex367 for storing encoded data or decoded data such as still images, recorded audio, received video, still images, mails, or the like, or an interface unit with a recording medium for storing data A slot ex364 is provided.

Furthermore, a configuration example of the mobile phone ex114 will be described with reference to FIG. 22B. The mobile phone ex114 has a power supply circuit part ex361, an operation input control part ex362, and a video signal processing part ex355 with respect to a main control part ex360 that comprehensively controls each part of the main body including the display part ex358 and the operation key part ex366. , A camera interface unit ex363, an LCD (Liquid Crystal Display) control unit ex359, a modulation / demodulation unit ex352, a multiplexing / demultiplexing unit ex353, an audio signal processing unit ex354, a slot unit ex364, and a memory unit ex367 are connected to each other via a bus ex370. ing.

When the end of call and the power key are turned on by a user operation, the power supply circuit unit ex361 starts up the mobile phone ex114 in an operable state by supplying power from the battery pack to each unit.

The cellular phone ex114 converts the audio signal collected by the audio input unit ex356 in the voice call mode into a digital audio signal by the audio signal processing unit ex354 based on the control of the main control unit ex360 having a CPU, a ROM, a RAM, and the like. Then, this is subjected to spectrum spread processing by the modulation / demodulation unit ex352, digital-analog conversion processing and frequency conversion processing are performed by the transmission / reception unit ex351, and then transmitted via the antenna ex350. The mobile phone ex114 also amplifies the received data received via the antenna ex350 in the voice call mode, performs frequency conversion processing and analog-digital conversion processing, performs spectrum despreading processing by the modulation / demodulation unit ex352, and performs voice signal processing unit After being converted into an analog audio signal by ex354, this is output from the audio output unit ex357.

Further, when an e-mail is transmitted in the data communication mode, the text data of the e-mail input by operating the operation key unit ex366 of the main unit is sent to the main control unit ex360 via the operation input control unit ex362. The main control unit ex360 performs spread spectrum processing on the text data in the modulation / demodulation unit ex352, performs digital analog conversion processing and frequency conversion processing in the transmission / reception unit ex351, and then transmits the text data to the base station ex110 via the antenna ex350. . In the case of receiving an e-mail, almost the reverse process is performed on the received data and output to the display unit ex358.

When transmitting video, still images, or video and audio in the data communication mode, the video signal processing unit ex355 compresses the video signal supplied from the camera unit ex365 by the moving image encoding method described in the above embodiments. Encode (that is, function as the image encoding apparatus of the present invention), and send the encoded video data to the multiplexing / demultiplexing unit ex353. The audio signal processing unit ex354 encodes the audio signal picked up by the audio input unit ex356 while the camera unit ex365 images a video, a still image, etc., and sends the encoded audio data to the multiplexing / separating unit ex353. To do.

The multiplexing / demultiplexing unit ex353 multiplexes the encoded video data supplied from the video signal processing unit ex355 and the encoded audio data supplied from the audio signal processing unit ex354 by a predetermined method, and is obtained as a result. The multiplexed data is subjected to spread spectrum processing by the modulation / demodulation unit (modulation / demodulation circuit unit) ex352, digital-analog conversion processing and frequency conversion processing by the transmission / reception unit ex351, and then transmitted via the antenna ex350.

Decode multiplexed data received via antenna ex350 when receiving video file data linked to a homepage, etc. in data communication mode, or when receiving e-mail with video and / or audio attached Therefore, the multiplexing / separating unit ex353 separates the multiplexed data into a video data bit stream and an audio data bit stream, and performs video signal processing on the video data encoded via the synchronization bus ex370. The encoded audio data is supplied to the audio signal processing unit ex354 while being supplied to the unit ex355. The video signal processing unit ex355 decodes the video signal by decoding using the video decoding method corresponding to the video encoding method shown in each of the above embodiments (that is, functions as the image decoding device of the present invention). For example, video and still images included in the moving image file linked to the home page are displayed from the display unit ex358 via the LCD control unit ex359. The audio signal processing unit ex354 decodes the audio signal, and the audio is output from the audio output unit ex357.

In addition to the transmission / reception type terminal having both the encoder and the decoder, the terminal such as the mobile phone ex114 is referred to as a transmission terminal having only an encoder and a receiving terminal having only a decoder. There are three possible mounting formats. Furthermore, in the digital broadcasting system ex200, it has been described that multiplexed data in which music data or the like is multiplexed with video data is received and transmitted, but data in which character data or the like related to video is multiplexed in addition to audio data It may be video data itself instead of multiplexed data.

As described above, the moving picture encoding method or the moving picture decoding method shown in each of the above embodiments can be used in any of the above-described devices / systems. The described effect can be obtained.

Further, the present invention is not limited to the above-described embodiment, and various changes and modifications can be made without departing from the scope of the present invention.

(Embodiment 8)
The moving picture coding method or apparatus shown in the above embodiments and the moving picture coding method or apparatus compliant with different standards such as MPEG-2, MPEG4-AVC, and VC-1 are appropriately switched as necessary. Thus, it is also possible to generate video data.

Here, when a plurality of pieces of video data conforming to different standards are generated, it is necessary to select a decoding method corresponding to each standard when decoding. However, since it is impossible to identify which standard the video data to be decoded complies with, there arises a problem that an appropriate decoding method cannot be selected.

In order to solve this problem, multiplexed data obtained by multiplexing audio data or the like with video data is configured to include identification information indicating which standard the video data conforms to. A specific configuration of multiplexed data including video data generated by the moving picture encoding method or apparatus shown in the above embodiments will be described below. The multiplexed data is a digital stream in the MPEG-2 transport stream format.

FIG. 23 is a diagram showing a structure of multiplexed data. As shown in FIG. 23, multiplexed data is obtained by multiplexing one or more of a video stream, an audio stream, a presentation graphics stream (PG), and an interactive graphics stream. The video stream indicates the main video and sub-video of the movie, the audio stream (IG) indicates the main audio portion of the movie and the sub-audio mixed with the main audio, and the presentation graphics stream indicates the subtitles of the movie. Here, the main video indicates a normal video displayed on the screen, and the sub-video is a video displayed on a small screen in the main video. The interactive graphics stream indicates an interactive screen created by arranging GUI components on the screen. The video stream is encoded by the moving image encoding method or apparatus shown in the above embodiments, or the moving image encoding method or apparatus conforming to the conventional standards such as MPEG-2, MPEG4-AVC, and VC-1. ing. The audio stream is encoded by a method such as Dolby AC-3, Dolby Digital Plus, MLP, DTS, DTS-HD, or linear PCM.

Each stream included in the multiplexed data is identified by PID. For example, 0x1011 for video streams used for movie images, 0x1100 to 0x111F for audio streams, 0x1200 to 0x121F for presentation graphics, 0x1400 to 0x141F for interactive graphics streams, 0x1B00 to 0x1B1F are assigned to video streams used for sub-pictures, and 0x1A00 to 0x1A1F are assigned to audio streams used for sub-audio mixed with the main audio.

FIG. 24 is a diagram schematically showing how multiplexed data is multiplexed. First, a video stream ex235 composed of a plurality of video frames and an audio stream ex238 composed of a plurality of audio frames are converted into PES packet sequences ex236 and ex239, respectively, and converted into TS packets ex237 and ex240. Similarly, the data of the presentation graphics stream ex241 and interactive graphics ex244 are converted into PES packet sequences ex242 and ex245, respectively, and further converted into TS packets ex243 and ex246. The multiplexed data ex247 is configured by multiplexing these TS packets into one stream.

FIG. 25 shows in more detail how the video stream is stored in the PES packet sequence. The first row in FIG. 25 shows a video frame sequence of the video stream. The second level shows a PES packet sequence. As shown by arrows yy1, yy2, yy3, and yy4 in FIG. 25, a plurality of video presentation units in a video stream are divided into pictures, B pictures, and P pictures and stored in the payload of the PES packet. . Each PES packet has a PES header, and a PTS (Presentation Time-Stamp) that is a display time of a picture and a DTS (Decoding Time-Stamp) that is a decoding time of a picture are stored in the PES header.

FIG. 26 shows the format of the TS packet that is finally written in the multiplexed data. The TS packet is a 188-byte fixed-length packet composed of a 4-byte TS header having information such as a PID for identifying a stream and a 184-byte TS payload for storing data. The PES packet is divided and stored in the TS payload. The In the case of a BD-ROM, a 4-byte TP_Extra_Header is added to a TS packet, forms a 192-byte source packet, and is written in multiplexed data. In TP_Extra_Header, information such as ATS (Arrival_Time_Stamp) is described. ATS indicates the transfer start time of the TS packet to the PID filter of the decoder. Source packets are arranged in the multiplexed data as shown in the lower part of FIG. 26, and the number incremented from the head of the multiplexed data is called SPN (source packet number).

In addition, TS packets included in the multiplexed data include PAT (Program Association Table), PMT (Program Map Table), PCR (Program Clock Reference), and the like in addition to each stream such as video / audio / caption. PAT indicates what the PID of the PMT used in the multiplexed data is, and the PID of the PAT itself is registered as 0. The PMT has the PID of each stream such as video / audio / subtitles included in the multiplexed data and the attribute information of the stream corresponding to each PID, and has various descriptors related to the multiplexed data. The descriptor includes copy control information for instructing permission / non-permission of copying of multiplexed data. In order to synchronize the ATC (Arrival Time Clock), which is the ATS time axis, and the STC (System Time Clock), which is the PTS / DTS time axis, the PCR corresponds to the ATS in which the PCR packet is transferred to the decoder. Contains STC time information.

FIG. 27 is a diagram for explaining the data structure of the PMT in detail. A PMT header describing the length of data included in the PMT is arranged at the head of the PMT. After that, a plurality of descriptors related to multiplexed data are arranged. The copy control information and the like are described as descriptors. After the descriptor, a plurality of pieces of stream information regarding each stream included in the multiplexed data are arranged. The stream information includes a stream descriptor in which a stream type, a stream PID, and stream attribute information (frame rate, aspect ratio, etc.) are described to identify a compression codec of the stream. There are as many stream descriptors as the number of streams existing in the multiplexed data.

When recording on a recording medium or the like, the multiplexed data is recorded together with the multiplexed data information file.

As shown in FIG. 28, the multiplexed data information file is management information of multiplexed data, has a one-to-one correspondence with the multiplexed data, and includes multiplexed data information, stream attribute information, and an entry map.

The multiplexed data information includes a system rate, a reproduction start time, and a reproduction end time as shown in FIG. The system rate indicates a maximum transfer rate of multiplexed data to a PID filter of a system target decoder described later. The ATS interval included in the multiplexed data is set to be equal to or less than the system rate. The playback start time is the PTS of the first video frame of the multiplexed data, and the playback end time is set by adding the playback interval for one frame to the PTS of the video frame at the end of the multiplexed data.

In the stream attribute information, as shown in FIG. 29, attribute information about each stream included in the multiplexed data is registered for each PID. The attribute information has different information for each video stream, audio stream, presentation graphics stream, and interactive graphics stream. The video stream attribute information includes the compression codec used to compress the video stream, the resolution of the individual picture data constituting the video stream, the aspect ratio, and the frame rate. It has information such as how much it is. The audio stream attribute information includes the compression codec used to compress the audio stream, the number of channels included in the audio stream, the language supported, and the sampling frequency. With information. These pieces of information are used for initialization of the decoder before the player reproduces it.

In this embodiment, among the multiplexed data, the stream type included in the PMT is used. Also, when multiplexed data is recorded on the recording medium, video stream attribute information included in the multiplexed data information is used. Specifically, in the video encoding method or apparatus shown in each of the above embodiments, the video encoding shown in each of the above embodiments for the stream type or video stream attribute information included in the PMT. There is provided a step or means for setting unique information indicating that the video data is generated by the method or apparatus. With this configuration, it is possible to discriminate between video data generated by the moving picture encoding method or apparatus described in the above embodiments and video data compliant with other standards.

FIG. 30 shows steps of the moving picture decoding method according to the present embodiment. In step exS100, the stream type included in the PMT or the video stream attribute information included in the multiplexed data information is acquired from the multiplexed data. Next, in step exS101, it is determined whether or not the stream type or the video stream attribute information indicates multiplexed data generated by the moving picture encoding method or apparatus described in the above embodiments. To do. When it is determined that the stream type or the video stream attribute information is generated by the moving image encoding method or apparatus described in the above embodiments, in step exS102, the above embodiments are performed. Decoding is performed by the moving picture decoding method shown in the form. If the stream type or video stream attribute information indicates that it conforms to a standard such as conventional MPEG-2, MPEG4-AVC, or VC-1, in step exS103, the conventional information Decoding is performed by a moving image decoding method compliant with the standard.

In this way, by setting a new unique value in the stream type or video stream attribute information, whether or not decoding is possible with the moving picture decoding method or apparatus described in each of the above embodiments is performed. Judgment can be made. Therefore, even when multiplexed data conforming to different standards is input, an appropriate decoding method or apparatus can be selected, and therefore decoding can be performed without causing an error. In addition, the moving picture encoding method or apparatus or the moving picture decoding method or apparatus described in this embodiment can be used in any of the above-described devices and systems.

(Embodiment 9)
The moving picture encoding method and apparatus and moving picture decoding method and apparatus described in the above embodiments are typically realized by an LSI that is an integrated circuit. As an example, FIG. 31 shows a configuration of an LSI ex500 that is made into one chip. The LSI ex500 includes elements ex501, ex502, ex503, ex504, ex505, ex506, ex507, ex508, and ex509 described below, and each element is connected via a bus ex510. The power supply circuit unit ex505 is activated to an operable state by supplying power to each unit when the power supply is on.

For example, when performing the encoding process, the LSI ex500 performs the microphone ex117 and the camera ex113 by the AV I / O ex509 based on the control of the control unit ex501 including the CPU ex502, the memory controller ex503, the stream controller ex504, the drive frequency control unit ex512, and the like. The AV signal is input from the above. The input AV signal is temporarily stored in an external memory ex511 such as SDRAM. Based on the control of the control unit ex501, the accumulated data is divided into a plurality of times as appropriate according to the processing amount and the processing speed and sent to the signal processing unit ex507, and the signal processing unit ex507 encodes an audio signal and / or video. Signal encoding is performed. Here, the encoding process of the video signal is the encoding process described in the above embodiments. The signal processing unit ex507 further performs processing such as multiplexing the encoded audio data and the encoded video data according to circumstances, and outputs the result from the stream I / Oex 506 to the outside. The output multiplexed data is transmitted to the base station ex107 or written to the recording medium ex215. It should be noted that data should be temporarily stored in the buffer ex508 so as to be synchronized when multiplexing.

In the above description, the memory ex511 is described as an external configuration of the LSI ex500. However, a configuration included in the LSI ex500 may be used. The number of buffers ex508 is not limited to one, and a plurality of buffers may be provided. The LSI ex500 may be made into one chip or a plurality of chips.

In the above description, the control unit ex501 includes the CPU ex502, the memory controller ex503, the stream controller ex504, the drive frequency control unit ex512, and the like, but the configuration of the control unit ex501 is not limited to this configuration. For example, the signal processing unit ex507 may further include a CPU. By providing a CPU also in the signal processing unit ex507, the processing speed can be further improved. As another example, the CPU ex502 may be configured to include a signal processing unit ex507 or, for example, an audio signal processing unit that is a part of the signal processing unit ex507. In such a case, the control unit ex501 is configured to include a signal processing unit ex507 or a CPU ex502 having a part thereof.

In addition, although it was set as LSI here, it may be called IC, system LSI, super LSI, and ultra LSI depending on the degree of integration.

Further, the method of circuit integration is not limited to LSI, and implementation with a dedicated circuit or a general-purpose processor is also possible. An FPGA (Field Programmable Gate Array) that can be programmed after manufacturing the LSI or a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI may be used.

Furthermore, if integrated circuit technology that replaces LSI emerges as a result of progress in semiconductor technology or other derived technology, it is naturally possible to integrate functional blocks using this technology. Biotechnology can be applied.

(Embodiment 10)
When decoding the video data generated by the moving picture encoding method or apparatus shown in the above embodiments, the video data conforming to the conventional standards such as MPEG-2, MPEG4-AVC, and VC-1 is decoded. It is conceivable that the amount of processing increases compared to the case. Therefore, in LSI ex500, it is necessary to set a driving frequency higher than the driving frequency of CPU ex502 when decoding video data compliant with the conventional standard. However, when the drive frequency is increased, there is a problem that power consumption increases.

In order to solve this problem, moving picture decoding devices such as the television ex300 and LSI ex500 are configured to identify which standard the video data conforms to and switch the driving frequency in accordance with the standard. FIG. 32 shows a configuration ex800 in the present embodiment. The drive frequency switching unit ex803 sets the drive frequency high when the video data is generated by the moving image encoding method or apparatus described in the above embodiments. Then, the decoding processing unit ex801 that executes the moving picture decoding method described in each of the above embodiments is instructed to decode the video data. On the other hand, when the video data is video data compliant with the conventional standard, compared to the case where the video data is generated by the moving picture encoding method or apparatus shown in the above embodiments, Set the drive frequency low. Then, it instructs the decoding processing unit ex802 compliant with the conventional standard to decode the video data.

More specifically, the drive frequency switching unit ex803 includes the CPU ex502 and the drive frequency control unit ex512 in FIG. Also, the decoding processing unit ex801 that executes the moving picture decoding method shown in each of the above embodiments and the decoding processing unit ex802 that complies with the conventional standard correspond to the signal processing unit ex507 in FIG. The CPU ex502 identifies which standard the video data conforms to. Then, based on the signal from the CPU ex502, the drive frequency control unit ex512 sets the drive frequency. Further, based on the signal from the CPU ex502, the signal processing unit ex507 decodes the video data. Here, for the identification of the video data, for example, it is conceivable to use the identification information described in the eighth embodiment. The identification information is not limited to that described in Embodiment 8, and any information that can identify which standard the video data conforms to may be used. For example, it is possible to identify which standard the video data conforms to based on an external signal that identifies whether the video data is used for a television or a disk. In some cases, identification may be performed based on such an external signal. In addition, the selection of the driving frequency in the CPU ex502 may be performed based on, for example, a lookup table in which video data standards and driving frequencies are associated with each other as shown in FIG. The look-up table is stored in the buffer ex508 or the internal memory of the LSI, and the CPU ex502 can select the drive frequency by referring to the look-up table.

FIG. 33 shows steps for executing the method of the present embodiment. First, in step exS200, the signal processing unit ex507 acquires identification information from the multiplexed data. Next, in step exS201, the CPU ex502 identifies whether the video data is generated by the encoding method or apparatus described in each of the above embodiments based on the identification information. When the video data is generated by the encoding method or apparatus shown in the above embodiments, in step exS202, the CPU ex502 sends a signal for setting the drive frequency high to the drive frequency control unit ex512. Then, the drive frequency control unit ex512 sets a high drive frequency. On the other hand, if it indicates that the video data conforms to the conventional standards such as MPEG-2, MPEG4-AVC, and VC-1, in step exS203, the CPU ex502 drives the signal for setting the drive frequency low. This is sent to the frequency control unit ex512. Then, in the drive frequency control unit ex512, the drive frequency is set to be lower than that in the case where the video data is generated by the encoding method or apparatus described in the above embodiments.

Furthermore, the power saving effect can be further enhanced by changing the voltage applied to the LSI ex500 or the device including the LSI ex500 in conjunction with the switching of the driving frequency. For example, when the drive frequency is set low, it is conceivable that the voltage applied to the LSI ex500 or the device including the LSI ex500 is set low as compared with the case where the drive frequency is set high.

In addition, the setting method of the driving frequency may be set to a high driving frequency when the processing amount at the time of decoding is large, and to a low driving frequency when the processing amount at the time of decoding is small. It is not limited to the method. For example, the amount of processing for decoding video data compliant with the MPEG4-AVC standard is larger than the amount of processing for decoding video data generated by the moving picture encoding method or apparatus described in the above embodiments. It is conceivable that the setting of the driving frequency is reversed to that in the case described above.

Furthermore, the method for setting the drive frequency is not limited to the configuration in which the drive frequency is lowered. For example, when the identification information indicates that the video data is generated by the moving image encoding method or apparatus described in the above embodiments, the voltage applied to the LSIex500 or the apparatus including the LSIex500 is set high. However, when it is shown that the video data conforms to the conventional standards such as MPEG-2, MPEG4-AVC, VC-1, etc., it is also possible to set the voltage applied to the LSIex500 or the device including the LSIex500 low. It is done. As another example, when the identification information indicates that the video data is generated by the moving image encoding method or apparatus described in the above embodiments, the driving of the CPU ex502 is stopped. If the video data conforms to the standards such as MPEG-2, MPEG4-AVC, VC-1, etc., the CPU ex502 is temporarily stopped because there is room in processing. Is also possible. Even when the identification information indicates that the video data is generated by the moving image encoding method or apparatus described in each of the above embodiments, if there is a margin for processing, the CPU ex502 is temporarily driven. It can also be stopped. In this case, it is conceivable to set the stop time shorter than in the case where the video data conforms to the conventional standards such as MPEG-2, MPEG4-AVC, and VC-1.

Thus, it is possible to save power by switching the drive frequency according to the standard to which the video data conforms. In addition, when the battery is used to drive the LSI ex500 or the device including the LSI ex500, it is possible to extend the life of the battery with power saving.

(Embodiment 11)
A plurality of video data that conforms to different standards may be input to the above-described devices and systems such as a television and a mobile phone. As described above, the signal processing unit ex507 of the LSI ex500 needs to support a plurality of standards in order to be able to decode even when a plurality of video data complying with different standards is input. However, when the signal processing unit ex507 corresponding to each standard is used individually, there is a problem that the circuit scale of the LSI ex500 increases and the cost increases.

In order to solve this problem, a decoding processing unit for executing the moving picture decoding method shown in each of the above embodiments and a decoding conforming to a standard such as MPEG-2, MPEG4-AVC, or VC-1 The processing unit is partly shared. An example of this configuration is shown as ex900 in FIG. 35A. For example, the moving picture decoding method shown in each of the above embodiments and the moving picture decoding method compliant with the MPEG4-AVC standard are processed in processes such as entropy coding, inverse quantization, deblocking filter, and motion compensation. Some contents are common. For the common processing content, the decoding processing unit ex902 corresponding to the MPEG4-AVC standard is shared, and for the other processing content unique to the present invention not corresponding to the MPEG4-AVC standard, the dedicated decoding processing unit ex901 is used. Configuration is conceivable. Regarding the sharing of the decoding processing unit, regarding the common processing content, the decoding processing unit for executing the moving picture decoding method described in each of the above embodiments is shared, and the processing content specific to the MPEG4-AVC standard As for, a configuration using a dedicated decoding processing unit may be used.

Further, ex1000 in FIG. 35B shows another example in which processing is partially shared. In this example, a dedicated decoding processing unit ex1001 corresponding to processing content unique to the present invention, a dedicated decoding processing unit ex1002 corresponding to processing content specific to other conventional standards, and a moving picture decoding method of the present invention A common decoding processing unit ex1003 corresponding to processing contents common to other conventional video decoding methods is used. Here, the dedicated decoding processing units ex1001 and ex1002 are not necessarily specialized in the processing content specific to the present invention or other conventional standards, and may be capable of executing other general-purpose processing. Also, the configuration of the present embodiment can be implemented by LSI ex500.

As described above, by sharing the decoding processing unit with respect to the processing contents common to the moving picture decoding method of the present invention and the moving picture decoding method of the conventional standard, the circuit scale of the LSI is reduced, and the cost is reduced. It is possible to reduce.

The moving picture encoding method and the moving picture decoding method according to the present invention can be applied to any multimedia data, and can improve the compression rate. For example, a mobile phone, a DVD device, a personal computer, etc. It is useful as a moving image encoding method and a moving image decoding method in storage, transmission, communication, etc.

DESCRIPTION OF SYMBOLS 100 Moving image encoder 101 Orthogonal transformation part 102 Quantization part 103 Inverse quantization part 104 Inverse orthogonal transformation part 105 Block memory 106 Frame memory 107 Intra prediction part 108 Inter prediction part 109 Inter prediction control part 110 Picture type determination part 111 Time Direct vector calculation unit 112 co-located reference direction determination unit 113 variable length coding unit 200 video decoding device 201 variable length decoding unit 202 inverse quantization unit 203 inverse orthogonal transform unit 204 block memory 205 frame memory 206 intra prediction unit 207 Inter prediction unit 208 Inter prediction control unit 209 Temporal direct vector calculation unit

Claims (27)

1. A moving picture coding method for coding a coding target block included in a coding target picture,
   Scaling a reference motion vector of a reference block that is included in a reference picture different from the encoding target picture and whose position in the reference picture is the same as the position of the encoding target block in the encoding target picture A calculation step of calculating motion vector candidates of the encoding target block;
   A predetermined motion vector is used to encode an encoding target block, and an error value between the predetermined motion vector and the motion vector candidate and information for specifying the selected motion vector candidate are encoded. An encoding step;
   A moving picture encoding method including:
2. In the calculating step, a first motion vector candidate and a second motion vector candidate of the encoding target block are calculated,
   The moving image encoding method further includes a selection step of selecting a motion vector candidate having a small error from the predetermined motion vector among the first motion vector candidate and the second motion vector candidate.
   In the encoding step, the encoding target block is encoded using the predetermined motion vector, and the error value corresponding to the selected motion vector candidate and information for specifying the selected motion vector candidate are included. The video encoding method according to claim 1, wherein encoding is performed.
3. The moving image encoding method according to claim 1, wherein the predetermined motion vector is a motion vector calculated by motion detection.
4. The information for specifying the motion vector candidate is an index,
   4. The moving image encoding method according to claim 2, wherein in the encoding step, when the index is encoded, a code string having a longer code length is assigned as the index value becomes larger. 5.
5. The reference block has a first reference motion vector that refers to a picture that is forward in display order from the reference picture, and a second reference motion vector that refers to a picture that is backward in display order from the reference picture. And
   In the calculating step, the first motion vector candidate is calculated using the first reference motion vector, and the second motion vector candidate is calculated using the second reference motion vector. The moving picture encoding method according to any one of claims 2 to 4, wherein a motion vector candidate is calculated.
6. In the encoding step, when the reference block is positioned ahead in the display order with respect to the encoding target block, an index value corresponding to the first motion vector candidate is set to the second motion vector candidate. Smaller than the index value corresponding to the motion vector candidate,
   If the reference block is located behind the encoding target block in the display order, an index value corresponding to the second motion vector candidate corresponds to the first motion vector candidate. The moving image encoding method according to claim 5, wherein the moving image encoding method is smaller than an index value.
7. The reference block has two reference motion vectors;
   In the calculating step, a first motion vector candidate is obtained using a reference motion vector having a small number of pictures included between the reference picture and another picture to which the reference picture refers, among the reference motion vectors. Calculating a second motion vector candidate using the other reference motion vector;
   5. The encoding step, wherein an index value corresponding to the first motion vector candidate is made smaller than an index value corresponding to the second motion vector candidate. 6. The moving image encoding method described in 1.
8. In the selection step, when the reference block is positioned ahead in the display order from the encoding target block, and the reference block does not have a reference motion vector, the encoding target block Calculating the first motion vector candidate and the second motion vector candidate using the motion vector of the reference block located backward in the display order,
   When the reference block is located behind the encoding target block in the display order, and the reference block does not have a reference motion vector, the reference block is ahead of the encoding target block in the display order. The moving image code according to any one of claims 5 to 7, wherein the first motion vector candidate and the second motion vector candidate are calculated using a motion vector included in a reference block located at the position. Method.
9. In the selection step, in addition to the first motion vector candidate and the second motion vector candidate, a motion vector of a block adjacent to the left of the encoding target block is set as a third motion vector candidate, and the encoding target The motion vector of the block next to the block as the fourth motion vector candidate, the motion vector of the block right next to the encoding target block as the fifth motion vector candidate,
   The moving picture encoding method according to any one of claims 2 to 8, wherein a motion vector candidate having a smallest error value with respect to the predetermined motion vector is selected from the first to fifth motion vector candidates. .
10. A moving picture decoding method for decoding a decoding target block included in a decoding target picture,
    Scaling a reference motion vector of a reference block that is included in a reference picture different from the decoding target picture, and whose position in the reference picture is the same as the position of the decoding target block in the decoding target picture A first calculation step of calculating motion vector candidates of the decoding target block;
    A first decoding step of decoding error value information between a predetermined motion vector and the motion vector candidate;
    A second calculation step of adding the motion vector candidate and the error value information to calculate a motion vector;
    A second decoding step of decoding a decoding target block using the motion vector;
    A moving picture decoding method including:
11. A moving picture decoding method for decoding a decoding target block included in a decoding target picture,
    Scaling a reference motion vector of a reference block that is included in a reference picture different from the decoding target picture, and whose position in the reference picture is the same as the position of the decoding target block in the decoding target picture A first calculation step of calculating a first motion vector candidate of the decoding target block and a second motion vector candidate;
    Among the first motion vector candidate and the second motion vector candidate, an index value corresponding to a motion vector candidate having a small error from the predetermined motion vector is set as an index value corresponding to the other motion vector candidate. An index setting step that is larger than
    A first decoding step of decoding index information identifying motion vector candidates;
    A first decoding step of decoding error value information between a predetermined motion vector and the motion vector candidate specified by the index information;
    A second calculation step of adding the motion vector candidate specified by the index information and the error value information to calculate a motion vector;
    A second decoding step of decoding a decoding target block using the motion vector;
    A moving picture decoding method including:
12. The moving image decoding method according to claim 10 or 11, wherein the predetermined motion vector is a motion vector calculated by motion detection.
13. The reference block has a first reference motion vector that refers to a picture that is forward in display order from the reference picture, and a second reference motion vector that refers to a picture that is backward in display order from the reference picture. And
    In the first calculation step, the first motion vector candidate is calculated using the first reference motion vector, and the second motion vector candidate is calculated using the second reference motion vector. The moving picture decoding method according to claim 11, wherein the second motion vector candidate is calculated.
14. In the index setting step, when the reference block is positioned ahead in the display order from the decoding target block, an index value corresponding to the first motion vector candidate is set to the second motion vector candidate. Smaller than the index value corresponding to the motion vector candidate,
    When the reference block is located behind the decoding target block in the display order, an index value corresponding to the second motion vector candidate corresponds to the first motion vector candidate. The moving picture decoding method according to claim 13, wherein the moving picture decoding method is set to be smaller than an index value.
15. The reference block has two reference motion vectors;
    In the first calculation step, a first motion is generated using a reference motion vector having a small number of pictures included between the reference picture and another picture to which the reference picture refers, among the reference motion vectors. A vector candidate is calculated, a second motion vector candidate is calculated using the other reference motion vector,
    The moving picture decoding method according to claim 11, wherein, in the index setting step, an index value corresponding to the first motion vector candidate is made smaller than an index value corresponding to the second motion vector candidate.
16. In the first calculation step, when the reference block is positioned ahead of the encoding target block in the display order and the reference block does not have a reference motion vector, the encoding is performed. Calculating the first motion vector candidate and the second motion vector candidate using a motion vector of a reference block located behind the target block in display order;
    When the reference block is located behind the encoding target block in the display order, and the reference block does not have a reference motion vector, the reference block is ahead of the encoding target block in the display order. The moving picture decoding method according to claim 11, wherein the first motion vector candidate and the second motion vector candidate are calculated using a motion vector included in a reference block located at a position.
17. In the first calculation step,
    In addition to the first motion vector candidate and the second motion vector candidate, the motion vector of the block adjacent to the left of the encoding target block is set as a third motion vector candidate, and The motion vector of the block is the fourth motion vector candidate, the motion vector of the block on the upper right of the encoding target block is the fifth motion vector candidate, and the motion of the intermediate value of the third, fourth, and fifth motion vectors Let the vector be the sixth motion vector candidate,
    In the index setting step,
    The value of the index corresponding to the sixth motion vector candidate is the first value that is the minimum value,
    The index value corresponding to the third motion vector candidate is set to a second value that is the second largest next to the first value,
    The value of the index corresponding to the fourth motion vector candidate is set to a third value that is next to the second value,
    The index value corresponding to the fifth motion vector candidate is set to a fourth value that is the second largest next to the third value,
    The index value corresponding to the first motion vector candidate and the index value corresponding to the second motion vector candidate are set to values larger than the fourth value. The moving picture decoding method according to claim 1.
18. A moving picture encoding method for encoding the encoding target block using a reference motion vector of a reference block included in a reference picture different from the encoding target picture including the encoding target block,
    The reference block has the same position in the picture as the position of the encoding target block in the encoding target picture,
    If the reference block has more than one reference motion vector,
    An additional step of adding a predicted motion vector obtained from the reference motion vector to a predicted motion vector candidate based on whether the reference picture is ahead or behind the picture to be encoded;
    A selection step of selecting a predicted motion vector for encoding the motion vector of the encoding target block from the determined predicted motion vector candidates;
    A moving image including: an encoding step of calculating a motion vector error of the motion vector of the encoding target block using the selected prediction motion vector, and encoding the motion vector error and the index of the selected prediction motion vector. Image coding method.
19. In the adding step,
    If the reference block has the forward and backward reference motion vectors,
    When the encoding target block is located in front of the reference block,
    After adding the first predicted motion vector obtained from the reference motion vector referring forward to the reference motion vector to the predicted motion vector candidate, obtaining from the reference motion vector referring backward from among the reference motion vectors. Adding the second predicted motion vector to the predicted motion vector candidate;
    When the encoding target block is located behind the reference block,
    After adding the first predicted motion vector obtained from the reference motion vector referring backward from among the reference motion vectors to the predicted motion vector candidate, obtaining from the reference motion vector referring forward from among the reference motion vectors. The moving image encoding method according to claim 18, wherein the second predicted motion vector is added to the predicted motion vector candidate.
20. In the adding step,
    If the reference block has either the forward or backward reference motion vector,
    Regardless of the positional relationship between the reference block and the encoding target block,
    The moving picture coding method according to claim 18 or 19, wherein a predicted motion vector obtained from either the forward or backward reference motion vector of the reference block is added to the predicted motion vector candidate.
21. In the adding step,
    Among the two or more reference motion vectors, the predicted motion vector obtained from a reference motion vector having a small number of pictures included between a reference picture and another picture referred to by the reference picture is preceded by the predicted motion vector candidate. The moving picture encoding method according to claim 18, wherein the moving picture encoding method is added.
22. In the adding step,
    Among the two or more reference motion vectors, the predicted motion vector obtained from a reference motion vector having a small number of pictures included between a reference picture and another picture referred to by the reference picture is preceded by the predicted motion vector candidate. Add to
    When the number of pictures included between the reference picture and another picture referenced by the reference picture is the same in both of the two or more reference motion vectors,
    When the encoding target block is located in front of the reference block,
    After adding the first predicted motion vector obtained from the reference motion vector referring forward to the reference motion vector to the predicted motion vector candidate, obtaining from the reference motion vector referring backward from among the reference motion vectors. Adding the second predicted motion vector to the predicted motion vector candidate;
    When the encoding target block is located behind the reference block,
    After adding the first predicted motion vector obtained from the reference motion vector referring backward from among the reference motion vectors to the predicted motion vector candidate, obtaining from the reference motion vector referring forward from among the reference motion vectors. The moving image encoding method according to claim 18, wherein the second predicted motion vector is added to the predicted motion vector candidate.
23. The moving image according to claim 18, wherein the adding step adds the predicted motion vector obtained from a reference motion vector having a small vector size among two or more reference motion vectors to the predicted motion vector candidate first. Encoding method.
24. In the adding step,
    Adding the predicted motion vector obtained from a reference motion vector having a small vector size among two or more reference motion vectors to the predicted motion vector candidate first;
    If the magnitude of the vector is the same for two or more reference motion vectors,
    When the encoding target block is located in front of the reference block,
    After adding the first predicted motion vector obtained from the reference motion vector referring forward to the reference motion vector to the predicted motion vector candidate, obtaining from the reference motion vector referring backward from among the reference motion vectors. Adding the second predicted motion vector to the predicted motion vector candidate;
    When the encoding target block is located behind the reference block,
    After adding the first predicted motion vector obtained from the reference motion vector referring backward from among the reference motion vectors to the predicted motion vector candidate, obtaining from the reference motion vector referring forward from among the reference motion vectors. The moving image encoding method according to claim 18, wherein the second predicted motion vector is added to the predicted motion vector candidate.
25. In the adding step, when the reference block has neither the forward nor backward reference motion vector, the reference block is obtained from a new reference picture and the predicted motion vector is added to the predicted motion vector candidate. Item 19. A video encoding method according to Item 18.
26. When the reference picture is ahead of the encoding target picture, the new reference picture is a picture behind the encoding target picture,
    26. The moving picture encoding method according to claim 25, wherein, when the reference picture is behind the encoding target picture, the new picture is a picture ahead of the encoding target picture.
27. 27. The index of the motion vector predictor is allocated in the order of addition to the motion vector predictor candidates, and encoding is performed such that the amount of generated code decreases as the index motion vector index value decreases. The moving image encoding method according to any one of the preceding claims.

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