Abstract: An encoder that encodes a video includes a processor and memory. Using the memory, the processor: derives a prediction error of an image included in the video, by subtracting a prediction image of the image from the image; determines a secondary transform basis based on a primary transform basis, the primary transform basis being a transform basis for a primary transform to be performed on the prediction error, the secondary transform basis being a transform basis for a secondary transform to be performed on a result of the primary transform; performs the primary transform on the prediction error using the primary transform basis; performs the secondary transform on a result of the primary transform using the secondary transform basis; performs quantization on a result of the secondary transform; and encodes a result of the quantization as data of the image.

Abstract: An encoder includes circuitry and memory coupled to the circuitry. The circuitry, in operation: determines whether a size of a current block, which is a unit for which a vector candidate list including vector candidates is generated, is less than or equal to a threshold; when the size of the current block is less than or equal to the threshold, generates the vector candidate list by registering a history-based motion vector predictor (HMVP) vector candidate in the vector candidate list from an HMVP table without performing a first pruning process; when the size of the current block is greater than the threshold, generates the vector candidate list by performing the first pruning process and registering the HMVP vector candidate in the vector candidate list from the HMVP table; and encodes the current block using the vector candidate list.

Abstract: An encoder encodes a video, and includes: circuitry; and memory coupled to the circuitry. Using the memory, the circuitry: obtains at least two items of prediction information for a first partition included in the video; derives at least one template from neighboring samples which neighbor the first partition; calculates at least two costs, using the at least one template and the at least two items of prediction information; using the at least two costs, (i) determines at least one splitting direction for the first partition or (ii) assigns one of the at least two items of prediction information to a second partition split from the first partition according to the splitting direction, and another thereof to a third partition split from the first partition according to the splitting direction; and encodes the first partition according to the splitting direction and the at least two items of prediction information.

Abstract: An air intake structure includes a blower, a flow path that includes an inlet port that draws air and a flow path space connected to the inlet port to allow air drawn in through the inlet port to flow to the blower, and a recessed portion that protrudes to an outer side of the flow path space at a portion of the flow path adjacent to the inlet port, the recessed portion having a recessed space opening to the flow path space.

Abstract: A decoder comprises circuitry and memory. The circuitry, using the memory, in operation, determines a number of first pixels and a number of second pixels used in a deblocking filter process, wherein the first pixels are located at an upper side of a block boundary and the second pixels are located at a lower side of the block boundary, and performs the deblocking filter process on the block boundary. The number of the first pixels and the number of the second pixels are selected from among candidates, wherein the candidates include at least 4 and M larger than 4. Response to a location of the block boundary being a predetermined location, the number of the first pixels used in the deblocking filter process is limited to be 4.

Abstract: An encoder which encodes a video including a plurality of pictures includes circuitry and memory. Using the memory, the circuitry performs: encoding a first picture among the plurality of pictures; and performing (i) a first operation for encoding a parameter set for a second picture which follows the first picture in coding order among the plurality of pictures after encoding the first picture, and encoding the second picture after encoding the parameter set, or (ii) a second operation for encoding the second picture without encoding the parameter set after encoding the first picture. The circuitry performs the first operation when the second picture is a determined picture, in the performing of the first operation or the second operation.

Abstract: An encoder includes memory and circuitry coupled to the memory. The circuitry, for each of temporal sub-layers for temporal scalability different from spatial scalability, stores first parameters into buffering period supplemental enhancement information (SEI) and encodes the first parameters. The first parameters present initial delays in timing to extract data from a coded picture buffer (CPB). The circuitry stores a second parameter into the buffering period SEI and encodes the second parameter. The second parameter indicates a total number of the temporal sub-layers. A value of the second parameter is equal to a value of a third parameter that is encoded into a sequence parameter set and indicates a total number of the temporal sub-layers.

Abstract: An encoder that includes memory and circuitry coupled to the memory. The circuitry encodes a slice into one or more data access regions in a variable length encoding process. The circuitry encodes one or more offsets into a slice header, based on a flag written into a sequence header and a total number of the one or more data access regions. The one or more offsets each specify a head position of a corresponding one of the one or more data access regions in a bitstream. When the flag indicates that the one or more offsets are to be encoded and the total number is at least two, the one or more offsets are encoded. The flag switches between encoding and not encoding the one or more offsets regardless of whether the total number is at least two.

Abstract: An encoder includes circuitry, and memory coupled to the circuitry. The circuitry, in operation, for each of a plurality of sub-bitstreams having mutually different frame rates, encodes identification information into a header of a bitstream including the plurality of sub-bitstreams, the identification information indicating a temporal ID that is an identifier of a temporal layer related to a temporal scalability and corresponds to the sub-bitstream, and encodes level information indicating a conformance level of the sub-bitstream.

Abstract: An encoder includes circuitry and memory connected to the circuitry. In operation, the circuitry: corrects a base motion vector using a correction value for correcting the base motion vector in a predetermined direction; and encodes a current partition to be encoded in an image of a video, using the base motion vector corrected. The correction value is specified by a first parameter and a second parameter, the first parameter indicating a table to be selected from among a plurality of tables each including values, the second parameter indicating one of the values included in the table to be selected indicated by the first parameter. In each of the plurality of tables, a smaller value among the values is assigned a smaller index. Each of the plurality of tables includes a different minimum value among the values.

Abstract: An encoder includes circuitry and memory. Using the memory, the circuitry performs prediction on an image. A motion vector predictor list used in the prediction includes a spatially neighboring motion vector predictor obtained from a block spatially neighboring a current block, and a spatially broad motion vector predictor obtained from a block positioned at any of a plurality of predetermined positions in a second range that is broader than a first range that spatially neighbors the current block. The plurality of predetermined positions are defined by a regular interval using the top-left of a current picture as a reference point.

Abstract: An encoder which includes circuitry and memory. Using the memory, the circuitry generates a list which includes candidates for a first motion vector for a first partition. The list has a maximum list size and an order of the candidates, and at least one of the maximum list size or the order of the candidates is dependent on at least one of a partition size or a partition shape of the first partition. The circuitry selects the first motion vector from the candidates included in the list; encodes an index indicating the first motion vector among the candidates in the list into the bitstream based on the maximum list size; and generates the predicted image for the first partition using the first motion vector.

Abstract: An encoder includes circuitry and a memory coupled to the circuitry, wherein the circuitry, in operation, performs a partition process. The partition process includes calculating first values of a set of pixels between a first partition and a second partition in a current block, using a first motion vector for the first partition; calculating second values of the set of pixels, using a second motion vector for the second partition; and calculating third values of the set of pixels by weighting the first values and the second values. When a ratio of a width to a height of the current block is larger than 4 or a ratio of the height to the width of the current block is larger than 4, the circuitry disables the partition process.

Abstract: Provided is an encoder which includes circuitry and memory. Using the memory, the circuitry splits an image block into a plurality of partitions, obtains a prediction image for a partition, and encodes the image block using the prediction image. When the partition is not a non-rectangular partition, the circuitry obtains (i) a first prediction image for the partition, (ii) a gradient image for the first prediction image, and (iii) a second prediction image as the prediction image using the first prediction image and the gradient image. When the partition is a non-rectangular partition, the circuitry obtains the first prediction image as the prediction image without using the gradient image.

Abstract: An encoder includes circuitry and memory coupled to the circuitry. In operation, the circuitry: derives a motion vector of a current block by referring to at least one reference picture different from a picture to which the current block belongs; performs a mode for estimating, for each sub-block unit of sub-blocks obtained by splitting the current block, a surrounding region of the motion vector to correct the motion vector; determines whether to apply deblocking filtering to each of boundaries between neighboring ones of the sub-blocks; and applies the deblocking filtering to the boundary, based on a result of the determination.

Abstract: An encoder that encodes a video includes circuitry and memory connected to the circuitry. In operation, the circuitry: generates a prediction image on a per sub-block basis; and when a sub-block size is 4×4, applies a boundary smoothing process only to sub-block boundaries having boundary positions that are integer multiples of 8.

Abstract: Provided is an encoder which includes circuitry and memory. Using the memory, the circuitry splits an image block into a plurality of partitions, obtains a prediction image for a partition, and encodes the image block using the prediction image. When the partition is not a non-rectangular partition, the circuitry obtains (i) a first prediction image for the partition, (ii) a gradient image for the first prediction image, and (iii) a second prediction image as the prediction image using the first prediction image and the gradient image. When the partition is a non-rectangular partition, the circuitry obtains the first prediction image as the prediction image without using the gradient image.

Abstract: A decoder includes circuitry which, in operation, parses a first flag indicating whether a CCALF (cross component adaptive loop filtering) process is enabled for a first block located adjacent to a left side of a current block; parses a second flag indicating whether the CCALF process is enabled for a second block located adjacent to an upper side of the current block; determines a first index associated with a color component of the current block; and derives a second index indicating a context model, using the first flag, the second flag, and the first index. The circuitry, in operation, performs entropy decoding of a third flag indicating whether the CCALF process is enabled for the current block, using the context model indicated by the second index; and performs the CCALF process on the current block in response to the third flag indicating the CCALF process is enabled for the current block.

Abstract: A hydroelectric power generation system is included in a channel control system. The channel control system includes a command section that outputs a command value of a flow rate or pressure of a fluid, an opening degree control unit that calculates a target opening degree based on the command value, and a motor-operated valve installed in a channel through which the fluid flows. The valve opens and closes in accordance with the target opening degree. The hydroelectric power generation system includes a water turbine disposed in the channel, a generator driven by the water turbine, and a generator control unit that controls at least one of a torque and a number of rotations of the generator based on opening degree information that indicates a measured value of an actual opening degree of the valve or an opening degree estimated.

Abstract: A robot that transfers a substrate includes a hand, an arm, a substrate detector, and a substrate orientation examiner. The hand holds and transfers the substrate. The arm is connected to the hand and moves the hand. The substrate detector detects absence or presence of the substrate in a non-contact manner. The substrate orientation examiner examines an orientation of the substrate based on a height detected by the substrate detector at which the substrate is located when it is not held by the hand.