JP6097326B2 - Block size determination method, block size determination device, and block size determination program - Google Patents

Description

  The present invention relates to a block size determination method, a block size determination device, and a block size determination program for determining a block size to be encoded in a moving image encoding device.

  In recent years, with the spread of broadband services, it has become easier to view moving image content over a network, and it is said that more than half of the data on the network becomes moving image data. In this situation, in order to make effective use of the network bandwidth, moving picture coding is used. H.264 / AVC and other moving image encoding schemes can be mentioned. Further, as a method for improving the encoding efficiency, H.264 is used. 265 / HEVC is also mentioned. In HEVC (High Efficiency Video Coding), the encoding efficiency is H.264. While it is possible to improve to twice that of H.264, the encoding processing load increases explosively.

  One reason for this increase is the concept of CU (Coding Unit). H. In H.264, encoding processing is performed in units of 16 × 16 pixels called MB (MacroBlock). In HEVC, LCU (Large CU: maximum coding unit) can be variable size with a maximum of 64 × 64 pixels and CU less than that (64 × 64 pixels to 8 × 8 pixels). The HEVC reference software (HM) performs an encoding process for the CU size (4 patterns) to determine the optimum CU size. On the other hand, a method for determining the CU size at an early stage and speeding up the encoding process has been proposed (see, for example, Patent Document 1).

JP 2014-127891 A

  By the way, in the prior art described in Patent Document 1, the cost calculation for 4 layers (CU size is 64 × 64 pixels, 32 × 32 pixels, 16 × 16 pixels, 8 × 8 pixels) is not performed, and the cost calculation for 2 or 3 layers is optimal. The CU size can be determined.

  However, in principle, it is necessary to calculate costs for at least two layers, which is not sufficient from the viewpoint of speeding up.

  The present invention has been made in view of such circumstances, and in a moving image encoding apparatus, a block size determination that can reduce the number of times of cost calculation processing when performing encoding and increase the speed of arithmetic processing. It is an object to provide a method, a block size determining apparatus, and a block size determining program.

  The present invention relates to a block size determination method performed by a moving image encoding apparatus that determines the size of a target block for encoding a moving image and performs encoding based on the determined size of the target block. A provisional determination step of referring to the maximum encoding block of the reference frame and tentatively determining the size of the encoding target block to the size of the block having the maximum ratio in the maximum encoding block; and the maximum code A first determination step for determining whether or not an encoding mode occupying the largest in a block is an intra mode, and the result of determination in the first determination step is that the encoding mode is an intra mode. In this case, a second determination step of determining whether or not a condition that allows the temporarily determined size of the encoding target block to be increased by one size is satisfied If, as a result of the determination in the second determination step, the condition is satisfied, the temporarily determined size of the encoding target block is increased by one size to determine the size of the encoding target block, and the encoding mode Is not an intra mode, and if the condition is not satisfied, a block size determination step for determining the size of the encoding target block that is provisionally determined is included.

  The present invention relates to a block size determination method performed by a moving image encoding apparatus that determines the size of a target block for encoding a moving image and performs encoding based on the determined size of the target block. A provisional determination step of referring to the maximum encoding block of the reference frame and tentatively determining the size of the encoding target block to the size of the block having the maximum ratio in the maximum encoding block; and the maximum code A first determination step for determining whether or not an encoding mode occupying the largest proportion in a coded block is an intra mode, and the result of determination in the first determination step is that the encoding mode is not the intra mode. A second determination step for determining whether or not the encoding mode having the largest ratio in the maximum encoding block is the inter mode; As a result of the determination in the second determination step, when the encoding mode is an inter mode, it is determined whether or not a condition that allows the temporarily determined size of the encoding target block to be increased by one size is satisfied. As a result of the determination by the third determination step and the third determination step, when the condition is satisfied and the encoding mode is the intra mode, the temporarily determined size of the encoding target block is increased by one size. Then, when the encoding mode is neither intra mode nor inter mode and the conditions are not satisfied, the block size determination is determined to be the temporarily determined size of the encoding target block. And a step.

  The present invention is a block size determination method for determining the size of a unit to be encoded in HEVC (High Efficiency Video Coding) using the block size determination method according to claim 1 or 2, wherein When the quantization parameter used in the maximum encoding unit to be encoded is larger than a predetermined value, the size of the encoding target block determined by the block size determination method according to claim 1 is set as the size of the encoding target unit. When the quantization parameter is equal to or smaller than a predetermined value, the size of the encoding target block determined by the block size determination method according to claim 2 is determined as the size of the encoding target unit. And

  The present invention relates to a block size determination device that determines the size of a target block for encoding a moving image, and refers to the maximum encoded block of a reference frame and occupies the maximum encoded block. Temporary determination means for tentatively determining the size of the encoding target block to the size of the block having the maximum ratio, and determining whether or not the encoding mode having the maximum ratio in the maximum encoding block is the intra mode As a result of determination by the first determination unit and the first determination unit, when the encoding mode is the intra mode, the condition that the temporarily determined size of the block to be encoded can be increased by one size is satisfied. A second determination unit that determines whether or not the condition is satisfied; and, as a result of determination by the second determination unit, the encoding target block that is provisionally determined when the condition is satisfied The size is increased by one size and determined to be the size of the block to be encoded. When the encoding mode is not the intra mode and the condition is not satisfied, the block to be determined as the temporarily determined size of the block to be encoded Size determining means.

  The present invention relates to a block size determination device that determines the size of a target block for encoding a moving image, and refers to the maximum encoded block of a reference frame and occupies the maximum encoded block. Temporary determination means for tentatively determining the size of the encoding target block to the size of the block having the maximum ratio, and determining whether or not the encoding mode having the maximum ratio in the maximum encoding block is the intra mode As a result of determination by the first determination unit and the first determination unit, when the encoding mode is not the intra mode, the encoding mode having the largest ratio in the maximum encoding block is the inter mode. A second determination means for determining whether or not the encoding mode is an inter mode as a result of the determination by the second determination means; A third determination unit that determines whether or not a condition capable of increasing the size of the block to be encoded by one size is satisfied; a result of determination by the third determination unit; When the mode is an intra mode, the temporarily determined size of the encoding target block is increased by one size to determine the size of the encoding target block, and the encoding mode is neither an intra mode nor an inter mode, If the condition is not satisfied, a block size determining unit that determines the size of the encoding target block that is provisionally determined is provided.

  The present invention is a block size determination program for causing a computer to execute the block size determination method.

  According to the present invention, it is possible to increase the speed of arithmetic processing by reducing the number of times of cost calculation processing.

It is a block diagram which shows the structure of the processing apparatus which performs CU size determination in which the reference software (HM) is mounted. It is explanatory drawing which shows the extraction method of the optimal CU division | segmentation. It is explanatory drawing which shows the example of CU division | segmentation after the optimization in the case shown in FIG. It is a figure which shows the example which aimed at speeding-up using the technique of patent document 1. FIG. It is a block diagram which shows the structure of the moving image encoder by 1st Embodiment of this invention. 6 is a flowchart showing an operation of a process (pre-process) in which the pre-processing unit 60 shown in FIG. 5 determines a CU size. It is explanatory drawing which shows the example of reference LCU. It is explanatory drawing which shows the processing operation of a 1st selection process. It is explanatory drawing which shows the processing operation of a 1st selection process. It is a flowchart which shows operation | movement of the process (pre-process) which determines CU size by 2nd Embodiment.

  Hereinafter, a moving picture coding apparatus according to an embodiment of the present invention will be described with reference to the drawings. The present embodiment speeds up the encoding process by determining the encoding target size (CU) in image encoding. For example, H.C. It can be used for block size determination in H.264, and size determination of CU (Coding Unit), PU (Prediction Unit), and TU (Transform Unit) in HEVC. Hereinafter, the determination of the HEVC CU size will be described as an example.

  This embodiment is not a method of calculating the cost for at least two layers, but determines the optimal CU size by calculating the cost for at least one layer, so the amount of calculation can be reduced compared to the conventional method. Yes, it is possible to speed up the arithmetic processing.

  FIG. 1 is a block diagram illustrating a configuration of a processing apparatus that performs CU size determination in which reference software (HM) distributed by an HEVC standardization organization is installed. First, when the CU size is 64 pixels × 64 pixels (hereinafter, n pixels xn pixels are referred to as nxn (n is 8, 16, 32, 64)), the 64 × 64 cost calculation unit 10 performs RD (Rate Distortion). Calculate the cost.

  Next, similarly, the 32 × 32 cost calculation unit 20, the 16 × 16 cost calculation unit 30, and the 8 × 8 cost calculation unit 40 calculate the RD cost in each CU size layer. The 32 × 32 RD cost is a combination of four 32 × 32 size costs so that the area is 64 × 64. Similarly, the 16x16 RD cost is the sum of 16 16x16 size costs, and the 8x8 cost is the sum of 64 8x8 size costs.

  Using these results, the CU pattern optimization unit 50 extracts the optimal CU partitioning method in the LCU, determines the CU size, and outputs it. FIG. 2 is an explanatory diagram showing an optimal CU partition extraction method. First, the RD cost is calculated from the 64 × 64 CU size, and then the size is set to the vertical and horizontal half (original 1/4 size) 32 × 32, and the respective RD costs are calculated.

  The RD cost is the sum of the generated information amount and the flag information. The numerical value described in the divided unit is the amount of generated information. Further, for example, the CU (lower left unit) in the hatched portion is set to 16 × 16 in the vertical and horizontal half (original 1/16 size), and the RD cost is calculated. Finally, for example, the CU (upper left unit) of the shaded portion of the vertical line is set to 8 × 8 in the vertical and horizontal half (original 1/64 size), and the RD cost is calculated.

  For example, if the flag information indicating the division state of the CU requires an information amount of 10 per flag, the generated information amount of the 32 × 32 layer is 200 + 210 + 300 + 220 = 930, and the flag information is 10 × 4 = 40. The cost is 970. This is smaller than the RD cost of 64 × 64 (the generated information amount is 1000 for 64 × 64, and the RD cost is 1000 because the flag information is 0). In this case, the total amount of information can be reduced by dividing the CU into four and selecting 32 × 32.

  Next, the total amount of information can be reduced by dividing the CU in the shaded portion of the vertical line similarly, for example (RD cost = 80 + 60 + 30 + 50 + 10 × 4 = 260), and the CU in the shaded portion of the vertical line is further divided. The total amount of information can be reduced (RD cost = 10 + 10 + 5 + 10 + 10 × 4 = 75). In this way, a CU division pattern that reduces the RD cost is extracted. FIG. 3 is an explanatory diagram showing an example of CU division after optimization in the case shown in FIG. In the example shown in FIG. 3, since the amount of generated information is 805, the RD cost becomes 925 even if flag information (3 × 10 × 4 = 120) is added, and the RD cost is reduced compared to the case where no division is performed. be able to.

  An example will be described in which the technique described in Patent Document 1 is used to increase the speed of processing that requires cost calculation for four layers of HM. FIG. 4 is a diagram showing an example of speeding up using the technique described in Patent Document 1. First, the cost calculation unit 100 calculates the RD cost of a certain CU size layer 1. Next, the cost calculation unit 200 calculates the RD cost of another CU size layer 2.

  The cost comparison unit 300 compares these RD costs. Based on the comparison result, the CU size can be determined as any one of the layers 1 to 4. In HM, cost calculation for four layers is required, whereas in this method, it is possible to determine the optimum CU size by calculating cost for two layers at a minimum.

<First Embodiment>
Next, the moving picture coding apparatus according to the first embodiment of the present invention will be described. FIG. 5 is a block diagram showing the configuration of the embodiment. In this figure, reference numeral 60 denotes a pre-processing unit that determines the CU size by performing pre-processing. Reference numeral 70 denotes a cost calculation unit that performs cost calculation using only the determined CU size (only for one layer). In the HM and the conventional method, the CU size is determined from the result of calculating the costs of a plurality of layers. In the present embodiment, the CU size is determined only by the pre-processing, and the cost is determined only by the determined CU size (for only one layer). Perform the calculation. The pre-processing has a very low processing load compared to the cost calculation.

  Next, with reference to FIG. 6, the operation of the processing (pre-processing) in which the pre-processing unit 60 shown in FIG. 5 determines the CU size will be described. FIG. 6 is a flowchart showing the operation of the processing (preprocessing) in which the preprocessing unit 60 shown in FIG. 5 determines the CU size. First, the pre-processing unit 60 performs a predetermined reference frame LCU (hereinafter referred to as a reference LCU) (which is spatially the same as an encoding target LCU in the encoding target frame (hereinafter referred to as a target LCU) in this description). Is referred to (step S1).

  Next, the pre-processing unit 60 provisionally determines the CU size having the highest area ratio in the reference LCU (ratio occupied in the reference LCU) as the CU size in the target LCU (step S2). For example, in the reference LCU, when the ratio of the 32 × 32 CU size is 75% and the ratio of the 16 × 16 CU size is 25%, the CU size is provisionally determined to be 32 × 32. If all the CU sizes in the reference LCU are 32 × 32, 32 × 32 is provisionally determined as the CU size. Further, in the reference LCU, when the proportion of the 32 × 32 CU size is 50% and the proportion of the 16 × 16 CU size is 50%, there are two highest CU sizes. In this case, the CU size 32 × 32, which is a large size, is provisionally determined as the CU size.

  When the processing shown in FIG. 6 is performed on all the frames, the CU size in the LCU should be one type, but whether or not to perform the processing shown in FIG. 6 can be selected. The reference LCU may have a plurality of types of CU sizes. In this case, a CU size having the highest area ratio in the reference LCU (occupied ratio in the reference LCU) is selected and temporarily determined as the selected CU size.

  Next, the pre-processing unit 60 determines whether or not the coding mode having the highest area ratio (ratio occupied in the LCU) in the reference LCU is intra (step S3), and the area ratio in the reference LCU is the highest. If the encoding mode is other than the intra mode, the CU size provisionally determined in step S2 is set as the final CU size, and the process ends (step S6). If the temporarily determined CU size is 32 × 32, the final CU size is 32 × 32.

On the other hand, when the coding mode having the highest area ratio in the reference LCU is the intra mode (Yes in step S3), the pre-processing unit 60 performs any one of the following conditional branches (step S4). The same effect is obtained under any conditions.
(A) The target CU has a low activity and a static area.
(B) The layer of the reference frame is not more than a predetermined value.

  Here, the activity means, for example, a luminance dispersion value. A layer means a hierarchy in a hierarchical structure GOP (Group Of Picture), where an I picture is a layer 0, a P picture is a layer 1, and the like. It should be noted that conditional branching may be performed under a condition in which a plurality of conditions among conditions (a) and (b) are combined with “and” or “or”.

When the condition in the conditional branch is satisfied (Yes in Step S4), the pre-processing unit 60 performs any one of the following (A) and (B), and sets the CU size provisionally determined in Step S2. Change (step S5). Both processes have the same effect.
(A) When the tentatively determined CU size is 32 × 32, the size is expanded to 64 × 64 (not applicable when the tentatively determined CU size is 8 × 8 or 16 × 16).
(B) One size larger than the tentatively determined CU size (applicable to all tentatively determined CU sizes of 8x8, 16x16, and 32x32).

  Here, increasing the size by one means that if the temporarily determined CU size is 8 × 8, the size is 16 × 16, and if the temporarily determined CU size is 16 × 16, the size is 32 × 32.

  On the other hand, when the condition in the conditional branch (step S4) is not satisfied, the pre-processing unit 60 sets the CU size provisionally determined in step S2 as the final CU size and ends the processing (step S6).

  The cost calculation unit 70 performs cost calculation using only the CU size (only one layer) determined after the processing operation of the pre-processing unit 60 illustrated in FIG. 6 is performed. When the processing operation shown in FIG. 6 is performed, only one type of CU size is stored in the LCU, so that the cost calculation process only needs to be performed once.

  As described above, when determining the unit size in image coding, by performing predetermined pre-processing (pre-processing), the number of times of cost calculation processing required for unit size determination, which has been conventionally required multiple times, is set to 1. The number of encoding operations can be suppressed as a result.

  In the above description, the reference LCU in the reference frame that is spatially the same as the target LCU is the predetermined reference LCU. However, as shown in FIG. The second selection process includes the inner LCU and a plurality of surrounding LCUs as candidates, taking into account the LCU selected by the first selection process and the motion vector in the reference frame LCU spatially identical to the target LCU. The same effect can be achieved with the LCU selected by the above.

  Here, the first selection process will be described with reference to FIG. For example, spatially identical reference frame LCUs and eight surrounding LCUs (9 in total) are used as reference LCU candidates. In this case, the LCU with the smallest number of CUs among the nine LCU candidates, here, the LCU with 13 CUs (shaded shaded portion) is selected as the predetermined reference LCU, and (a) , (B) conditional branching is performed.

  As reference LCU candidates for the first selection process, spatially identical reference frame LCUs and their peripheral LCUs are listed, but the entire LCU in the reference frame and the reference slice in the same slice as the target LCU are included. The same effect can be obtained even if the entire LCU and the entire LCU in the reference frame that is the same LCU line as the target LCU are candidates.

  Similarly, the second selection process will be described with reference to FIG. For example, assume that the target LCU size is 64 × 64 and the motion vectors in the spatially identical reference frame LCU are (48, −50). In this case, the lower right LCU (LCU indicated by a solid line) closest to the place where the spatially identical reference frame LCU is moved (48, -50) is selected as the reference LCU, taking into account the motion vector. The conditional branching of (a) and (b) is performed in the same manner as the above processing.

Second Embodiment
Next, a video encoding apparatus according to the second embodiment of the present invention will be described. Since the configuration in the second embodiment is the same as the configuration shown in FIG. 5, detailed description thereof is omitted here. The video encoding apparatus according to the second embodiment is different from the video encoding apparatus according to the first embodiment in that a part of the pre-processing processing operation is different. FIG. 10 is a flowchart showing the operation of the process (pre-process) for determining the CU size according to the second embodiment.

  With reference to FIG. 10, the operation of the CU size determination process (pre-process) in this embodiment will be described. First, the pre-processing unit 60 refers to a predetermined reference LCU of a reference frame (step S11), and temporarily determines a CU size having the highest area ratio in the reference LCU as a CU size in the target LCU (step S12). .

  Next, the pre-processing unit 60 determines whether or not the coding mode having the highest area ratio in the LCU is intra (step S13). As a result, when the encoding mode having the highest area ratio in the reference LCU is the intra mode, the processes (C) and (D) described later are performed, the provisionally determined CU size is changed, and the CU size is determined ( Step S16).

  On the other hand, when the coding mode having the highest area ratio in the reference LCU is not intra (No in step S13), the pre-processing unit 60 determines whether or not the coding mode having the highest area ratio in the LCU is inter. Determination is made (step S14). As a result, when the coding mode having the highest area ratio in the reference LCU is other than intra or inter coding (Skip mode or merge mode) (No in Step S14), the pre-processing unit 60 is provisionally determined in Step S12. The process is terminated with the CU size as the final CU size (step S17).

On the other hand, when the encoding mode having the highest area ratio in the reference LCU is the inter mode (Yes in step S14), the pre-processing unit 60 performs one conditional branch of any of the following (c) to (e). . Both conditions have the same effect.
(C) The target CU has a low activity and a static area.
(D) The motion vector is small in all CUs in the reference LCU.
(E) The layer of the reference frame is not more than a predetermined value.
It should be noted that conditional branching may be performed under a condition in which a plurality of conditions among conditions (c) to (e) are combined with “and” or “or”.

When the condition in the conditional branch is satisfied (Yes in step S15), the pre-processing unit 60 performs any of the following processes (C) and (D), and changes the CU size provisionally determined in step S12 ( Step S16).
(C) When the tentatively determined CU size is 32 × 32, the size is expanded to 64 × 64 (not applicable when the tentatively determined CU size is 8 × 8 or 16 × 16).
(D) One size larger than the temporarily determined CU size (applicable to all of the temporarily determined CU sizes of 8 × 8, 16 × 16, and 32 × 32).

  On the other hand, if the condition in the conditional branch is not satisfied, the pre-processing unit 60 sets the CU size provisionally determined in step S12 as the final CU size and ends the process (step S17).

  The cost calculation unit 70 performs cost calculation using only the CU size (only one layer) determined after performing the processing operation of the pre-processing unit 60 shown in FIG. When the processing operation shown in FIG. 10 is performed, the LCU has only one type of CU size, so that the cost calculation process can be performed only once.

  As described above, when determining the unit size in image coding, by performing predetermined pre-processing (pre-processing), the number of times of cost calculation processing required for unit size determination, which has been conventionally required multiple times, is set to 1. The number of encoding operations can be suppressed as a result.

  In the above description, the same effect can be obtained when the tentatively determined CU size is set to “final CU size” and “the maximum CU size in the reference LCU is set to final CU size”.

  Also, combining the first and second embodiments described above, or applying the first embodiment when the quantization parameter QP used in the target LCU is high, and applying the second embodiment when the QP is low. It is possible to achieve the same effect.

  As described above, when determining the unit size in image encoding, by performing predetermined pre-processing, the number of cost calculation processes required for unit size determination, which was conventionally required multiple times, is set to one time. As a result, the amount of encoding calculation can be suppressed.

  According to this configuration, it is possible to increase the speed of the encoding process by determining the encoding target size in the image encoding. In addition, by performing the processing described above, H.264 block size determination, H.264 In 265 / HEVC, processing can be performed at high speed when each size of CU (Coding Unit), PU (Prediction Unit), and TU (Transform Unit) is determined.

  You may make it implement | achieve all or one part of the moving image encoder in embodiment mentioned above with a computer. In that case, a program for realizing this function may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be read into a computer system and executed. Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory inside a computer system serving as a server or a client in that case may be included and a program held for a certain period of time. Further, the program may be a program for realizing a part of the above-described functions, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system. It may be realized using hardware such as PLD (Programmable Logic Device) or FPGA (Field Programmable Gate Array).

  As mentioned above, although embodiment of this invention has been described with reference to drawings, the said embodiment is only the illustration of this invention, and it is clear that this invention is not limited to the said embodiment. is there. Therefore, additions, omissions, substitutions, and other modifications of the components may be made without departing from the technical idea and scope of the present invention.

  It can also be applied to applications where it is indispensable to reduce the number of times of cost calculation processing and to speed up arithmetic processing.

  60: Pre-processing unit, 70: Cost calculation unit

Claims (9)

A block size determination method performed by a video encoding device that determines a size of a block to be encoded when encoding a video and performs encoding based on the determined size of the block to be encoded,
A provisional determination step of referring to the maximum encoding block of the reference frame and tentatively determining the size of the encoding target block to the size of the block having the maximum ratio in the maximum encoding block;
A first determination step of determining whether or not an encoding mode having a maximum ratio in the maximum encoding block is an intra mode;
As a result of the determination in the first determination step, when the encoding mode is the intra mode, the condition that the temporarily determined size of the encoding target block can be increased by one size is as follows . A second determination step for determining whether or not at least one of a point that the activity is low and the still region is satisfied and a point that the layer of the reference frame is equal to or less than a predetermined value is satisfied;
As a result of the determination in the second determination step, if the condition is satisfied, the temporarily determined size of the encoding target block is increased by one size to determine the size of the encoding target block, and the encoding mode is squid such in intra mode or, if that does not satisfy the above condition, the block size determination method characterized by having a block size determination step of determining the size of the temporary determined the encoding target block. 2. The block according to claim 1, wherein, in the block size determination step, when the temporarily determined size of the encoding target block is (32 × 32), the temporarily determined size of the encoding target block is expanded to (64 × 64). 3. Sizing method. In the block size determination step, if the temporarily determined size of the encoding target block is (8x8), (16x16), or (32x32), the size of the temporarily determined encoding target block is increased by one size. Item 2. The block size determination method according to Item 1. A block size determination method performed by a video encoding device that determines a size of a block to be encoded when encoding a video and performs encoding based on the determined size of the block to be encoded,
A provisional determination step of referring to the maximum encoding block of the reference frame and tentatively determining the size of the encoding target block to the size of the block having the maximum ratio in the maximum encoding block;
A first determination step of determining whether or not an encoding mode having a maximum ratio in the maximum encoding block is an intra mode;
As a result of the determination in the first determination step, when the encoding mode is not the intra mode, it is determined whether or not the encoding mode having the maximum ratio in the maximum encoding block is the inter mode. 2 determination steps;
As a result of the determination in the second determination step, when the encoding mode is the inter mode, as a condition that the temporarily determined size of the encoding target block can be increased by one size , the encoding target block The point that the activity is low and the area is still, the point that the motion vector is small in all the coding blocks in the maximum coding block of the reference frame, and the layer of the reference frame is equal to or less than a predetermined value. A third determination step for determining whether or not at least one of them is satisfied;
Results of the determination by the third determining step, carded satisfy the condition, prior SL when the coding mode is the intra mode, the encoding target size provisionally determined the encoding target block and one size larger determining the block size, squid do in the encoding mode inter mode in intra mode or, if that does not satisfy the above condition, a block size determination step of determining the size of the temporary determined the encoding target block A block size determination method comprising: A block size determination method for determining a size of an encoding target unit in HEVC (High Efficiency Video Coding) using the block size determination method according to any one of claims 1 to 4 .
The size of the encoding target block determined by the block size determination method according to any one of claims 1 to 3 , when a quantization parameter used in the maximum encoding unit to be encoded is larger than a predetermined value. Is determined as the size of the encoding target unit, and when the quantization parameter is equal to or smaller than a predetermined value, the size of the encoding target block determined by the block size determination method according to claim 4 is determined as the encoding target unit. A block size determination method characterized by determining as a size of a block. A block size determination device for determining the size of a block to be encoded when encoding a moving image,
Temporary determination means for temporarily determining the size of the block to be encoded to the size of the block having the maximum ratio in the maximum encoded block with reference to the maximum encoded block of the reference frame;
First determination means for determining whether or not an encoding mode having a maximum ratio in the maximum encoding block is an intra mode;
Said first determining means according to the determination result, when the coding mode is intra mode, the size of the temporary determined the encoding target block as a condition can be increased one size, in the encoding target block Second determination means for determining whether or not at least one of a point that the activity is low and a still area and a layer of the reference frame is equal to or less than a predetermined value is satisfied;
As a result of the determination by the second determination means, if the condition is satisfied, the temporarily determined size of the encoding target block is increased by one size to determine the size of the encoding target block, and the encoding mode is squid such in intra mode or, if that does not satisfy the above condition, the block size determining device, characterized in that it comprises a block size determining means for determining the size of the temporary determined the encoding target block. A block size determination device for determining the size of a block to be encoded when encoding a moving image,
Temporary determination means for temporarily determining the size of the block to be encoded to the size of the block having the maximum ratio in the maximum encoded block with reference to the maximum encoded block of the reference frame;
First determination means for determining whether or not an encoding mode having a maximum ratio in the maximum encoding block is an intra mode;
As a result of the determination by the first determination means, when the encoding mode is not the intra mode, it is determined whether or not the encoding mode having the maximum ratio in the maximum encoding block is the inter mode. Two determination means;
The second determination means according to the determination result, when the coding mode is an inter mode, the size of the temporary determined the encoding target block as a condition can be increased one size, in the encoding target block The point that the activity is low and the area is still, the point that the motion vector is small in all the coding blocks in the maximum coding block of the reference frame, and the layer of the reference frame is equal to or less than a predetermined value. Third determining means for determining whether or not at least one of them is satisfied;
Results of determination by said third determination means, carded satisfy the condition, prior SL when the coding mode is the intra mode, the encoding target size provisionally determined the encoding target block and one size larger determining the block size, squid do in the encoding mode inter mode in intra mode or, if that does not satisfy the above condition, the block size determining means for determining the size of the temporary determined the encoding target block A block size determining apparatus comprising: A block size determination method performed by a video encoding device that determines a size of a block to be encoded when encoding a video and performs encoding based on the determined size of the block to be encoded,
A provisional determination step of referring to the maximum encoding block of the reference frame and tentatively determining the size of the encoding target block to the size of the block having the maximum ratio in the maximum encoding block;
A first determination step of determining whether or not an encoding mode having a maximum ratio in the maximum encoding block is an intra mode;
A second determination step for determining whether or not a predetermined condition is satisfied when the encoding mode is an intra mode as a result of the determination in the first determination step;
As a result of determination by the second determination step, when the predetermined condition is satisfied, a third determination step of determining the temporarily determined size of the encoding target block;
A block size determining step for determining whether or not to temporarily increase the size of the encoding target block by one size according to a result of the determination of the size of the encoding target block determined temporarily;
A block size determination method characterized by comprising: A block size determination program for causing a computer to execute the block size determination method according to any one of claims 1 to 5 and 8 .

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