Abstract: An encoder includes circuitry and memory. In both of a first type of residual coding where an orthogonal transform is applied and a second type of residual coding where the orthogonal transform is skipped, wherein when a restriction on a number of CABAC processes allows CABAC coding of a set of coefficient information flags, the circuitry: encodes the coefficient information flags by CABAC; and otherwise, the circuitry: skips the CABAC encoding of the coefficient information flags; and the circuitry encodes a remainder value of the coefficient with Golomb-Rice code when the coefficient information flags are encoded; and otherwise the circuitry encodes a value of the coefficient with the Golomb-Rice code, wherein in the second type of residual coding, the circuitry encodes absolute value flags each relating to an absolute value of the coefficient after encoding the coefficient information flags and before encoding the remainder value of the coefficient.

Abstract: An encoder includes circuitry and memory coupled to the circuitry. The circuitry, in operation, for each coefficient of a plurality of coefficients included in a block, determines a base level relating to Context-Based Adaptive Binary Arithmetic Coding (CABAC) for the coefficient, and encodes an absolute value of the coefficient. In determining the base level, when one or more flags are used in encoding the absolute value of the coefficient, the base level is determined to be a first value, and when one or more flags are not used in the encoding, the base level is determined to be a second value that is smaller than the first value. In encoding the absolute value of the coefficient, when one or more flags are not used, a rice parameter is determined based on the base level which is equal to the second value, and the coefficient is binarized using the rice parameter.

Abstract: An encoder determines, based on a width and a height of a block, whether or not to disable a prediction mode in which the block is split along a partitioning line defined by a distance and an angle and then prediction is performed; and encodes the block with the prediction mode disabled or not disabled according to a result of the determination on whether or not to disable the prediction mode. Here, the distance is the shortest distance between the center of the block and the partitioning line, and the angle is an angle representing a direction from the center of the block toward the partitioning line in the shortest distance. The encoder determines to disable the prediction mode when (i) a width-to-height ratio is at least 8 or (ii) a height-to-width ratio is at least 8.

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 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 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 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: 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 perpendicular magnetic recording head is provided capable of suppressing the magnetic field attributable to the edge write phenomenon and improving resistance to an external magnetic field. The perpendicular magnetic recording head includes a magnetic layer that has a main magnetic pole on a surface facing a recording medium; a return yoke layer that is disposed on the magnetic layer with a nonmagnetic layer disposed therebetween and has a large width in the direction of the main magnetic pole; and a coil layer for applying a recording magnetic field to the magnetic layer. The return yoke layer is provided with such a shape that as seen in the plan view, the return yoke layer is exposed from the medium facing surface with a width not greater than the width in the track width direction of a protrusion region of the return yoke layer that covers the coil layer and the width of the return yoke layer gradually increases in the height direction from the medium facing surface.

Abstract: A vertical magnetic recording head device includes: a magnetic layer that includes a main magnetic pole exposed from a surface facing a recording medium; a return yoke layer that is provided on the magnetic layer with a non-magnetic layer interposed therebetween; and coil layers that apply a recording magnetic field to the magnetic layer and the return yoke layer. In the vertical magnetic recording head device, the return yoke layer includes thick portions that extend in a height direction in edge regions arranged in a track width direction.

Abstract: A perpendicular magnetic recording head according to the present invention is composed of a first magnetic layer having a main magnetic pole exposed at a facing surface opposite a recording medium, a second magnetic layer adjacent to the first magnetic layer with an intermediary non-magnetic layer disposed therebetween, and a coil layer for applying a recording magnetic field to the first magnetic layer. Since the second magnetic layer has a shape including a substantially arched portion in its cross section along a height direction, it becomes possible to keep an Edge Write magnetic field in a low level and improve external magnetic field resistance.

Abstract: A perpendicular magnetic recording head includes a first magnetic layer having a main magnetic pole exposed at a medium-facing surface that faces a recording medium; a second magnetic layer that faces the first magnetic layer with a nonmagnetic layer interposed therebetween; and a coil layer for applying a recording magnetic field to the first magnetic layer. The second magnetic layer includes a relatively thick edge portion, whereby the edge-write magnetic field is reduced and the external magnetic field resistance is increased.

Abstract: A perpendicular magnetic recording head includes a nonmagnetic insulating layer and a main magnetic pole layer disposed on the nonmagnetic insulating layer. The main magnetic pole layer includes a pole straight part exposed in an opposing surface opposite a recording medium and a flared part that extends from the pole straight part in a height direction. The flared part broadens in a track width direction as the flared part extends in the height direction. The pole straight part of the main magnetic pole layer as viewed from the opposing surface has a trapezoidal shape over its entire length, the trapezoidal shape being narrowed at the nonmagnetic insulating layer-side. The flared part as viewed from the opposing surface has a trapezoidal shape at least at a junction with the pole straight part, the trapezoidal shape being narrowed at the nonmagnetic insulating layer-side.

Abstract: A perpendicular magnetic recording head is provided capable of suppressing the magnetic field attributable to the edge write phenomenon and improving resistance to an external magnetic field. The perpendicular magnetic recording head includes a magnetic layer that has a main magnetic pole on a surface facing a recording medium; a return yoke layer that is disposed on the magnetic layer with a nonmagnetic layer disposed therebetween and has a large width in the direction of the main magnetic pole; and a coil layer for applying a recording magnetic field to the magnetic layer. The return yoke layer is provided with such a shape that as seen in the plan view, the return yoke layer is exposed from the medium facing surface with a width not greater than the width in the track width direction of a protrusion region of the return yoke layer that covers the coil layer and the width of the return yoke layer gradually increases as it goes toward the starting point of the height direction.

Abstract: A vertical magnetic recording head device includes: a magnetic layer that includes a main magnetic pole exposed from a surface facing a recording medium; a return yoke layer that is provided on the magnetic layer with a non-magnetic layer interposed therebetween; and coil layers that apply a recording magnetic field to the magnetic layer and the return yoke layer.

Abstract: A lens apparatus includes a plurality of lenses movable in a direction of the optical axis, a guide pole that extends in the direction of the optical axis and that is moved integrally with arbitrary lenses among the lenses, and a slide unit that is slidable along the guide pole and that is moved integrally with others lenses among the lenses. This makes an optical axis of the other lens moving along the guide pole to be aligned with an optical axis of the lens apparatus, by adjusting a position of the arbitrary lenses so that an optical axis of the arbitrary lenses is aligned with the optical axis of the lens apparatus.

Abstract: A perpendicular magnetic recording head includes a first magnetic layer having a main magnetic pole exposed at a medium-facing surface that faces a recording medium; a second magnetic layer that faces the first magnetic layer with a nonmagnetic layer interposed therebetween; and a coil layer for applying a recording magnetic field to the first magnetic layer. The second magnetic layer includes a relatively thick edge portion, whereby the edge-write magnetic field is reduced and the external magnetic field resistance is increased.

Abstract: A perpendicular magnetic recording head according to the present invention is composed of a first magnetic layer having a main magnetic pole exposed at a facing surface opposite a recording medium, a second magnetic layer adjacent to the first magnetic layer with an intermediary non-magnetic layer disposed therebetween, and a coil layer for applying a recording magnetic field to the first magnetic layer. Since the second magnetic layer has a shape including a substantially arched portion in its cross section along a height direction, it becomes possible to keep an Edge Write magnetic field in a low level and improve external magnetic field resistance.

Abstract: A perpendicular magnetic recording head includes a nonmagnetic insulating layer and a main magnetic pole layer disposed on the nonmagnetic insulating layer. The main magnetic pole layer includes a pole straight part exposed in an opposing surface opposite a recording medium and a flared part that extends from the pole straight part in a height direction. The flared part broadens in a track width direction as the flared part extends in the height direction. The pole straight part of the main magnetic pole layer as viewed from the opposing surface has a trapezoidal shape over its entire length, the trapezoidal shape being narrowed at the nonmagnetic insulating layer-side. The flared part as viewed from the opposing surface has a trapezoidal shape at least at a junction with the pole straight part, the trapezoidal shape being narrowed at the nonmagnetic insulating layer-side.