A magnetic recording medium in a shape of a tape that is long in a longitudinal direction and is short in a width direction is provided, the medium including: a base material; and a magnetic layer, in which the magnetic layer includes a data band long in the longitudinal direction in which a data signal is to be written, and a servo band long in the longitudinal direction in which a servo signal is written, and in the magnetic layer, a degree of vertical orientation is greater than or equal to 65%, a half width of a solitary waveform in a reproduction waveform of the servo signal is less than or equal to 195 nm, a thickness of the magnetic layer is less than or equal to 90 nm, and a thickness of the base material is less than or equal to 4.2 μm.

An information processing device includes a recording unit that records a plurality of objects including data and metadata related to the data on a magnetic recording medium, and executes, after recording at least one of the objects, processing of recording first set data which is a set of the metadata included in the object. The first set data is the set of the metadata included in the object recorded after recording the first set data that is recorded immediately before. The magnetic recording medium has a magnetic layer containing a ferromagnetic powder and a binding agent on a non-magnetic support. A difference between spacings S.sub.0.5 and S.sub.13.5 measured under pressures of 0.5 atm and 13.5 atm by an optical interference method after n-hexane cleaning on a surface of the magnetic layer is equal to or less than 3.0 nm.

A playback device reads out from a recording medium and plays multiple High Dynamic Range (HDR) video streams that are encoded with video information. The playback device includes a first register, a second register and a playback unit. For each of the HDR video streams, the first register stores first information indicating whether the playback device corresponds to or not, and the second register stores second information indicating whether a display device connected to the playback device corresponds to or not. The playback unit plays the HDR video streams using a playback format selected based on a playback program stored in the recording medium, in a case where the first information and the second information indicate that there are multiple playback formats corresponding to both the playback device and the display device.

A configuration capable of recording MMT format data in a medium as BDAV or SPAV format data and enabling the MMT format data to be reproduced is realized. MMT format data input via a broadcast wave or the like is input, and record data according to a BDAV format or an SPAV format is generated. A data processing unit generates an MMT format stream file storing the MMT format data as reproduction data and further generates a playlist file storing reproduction control information of the MMT format stream file and a clip information file.

Embodiments of the present invention provide a coding method, where the coding method includes: obtaining, based on a puncturing/shortening proportion P′ and a prestored sequence S′, a constructed sequence S that has a length equal to a target code length M, where S′ includes N′ channel indexes sorted by channel reliability or channel capacity, and sorting of channel indexes in S is the same as or different from sorting of channel indexes in S′; and mapping a to-be-sent bit sequence to a channel corresponding to S. According to this method, an appropriate constructed sequence S may be generated based on different puncturing/shortening proportions to perform coding, thereby decreasing a bit error rate.

A mark corresponding to recording data is formed on an optical disk by: encoding the recording data in accordance with a modulation code and generating encoded data; classifying the encoded data by a combination of at least two of a mark length of a mark, a space length of a preceding space, the mark length of a preceding mark, and the space length of a succeeding space; setting a correction amount for adjusting the position of the start edge and the end edge of a recording pulse based on an evaluation index of a decoding result, which is a result of decoding a reproduction signal of the encoded data, for each of the classification; and generating the recording pulse corresponding to the encoded data by using the correction amount corresponding to the classification of the run length of the encoded data.

The disclosed technology provides a method that improves CCT in SMR device systems. In one implementation, the method comprises writing data to a shingled magnetic recording (SMR) band in a storage device, determining whether an off-track write has occurred, identifying unsafe written data in response to determining that an off-track write has occurred, determining whether caching space is available upon identifying unsafe written data, continue writing data to the SMR band without a write retry upon determining that caching space is available, and writing unsafe written data to the available caching space. In another implementation, the method comprises receiving a request to repair an encroached track in an SMR band, recovering encroached data to a dynamic random-access memory, determining whether caching space is available, writing the recovered data to the available caching space upon determining that caching space is available, and merging other cached data in the SMR band.

According to one embodiment, a magnetic disk device includes a plurality of disks including a first area to which data is randomly written in normal recording and to which an LBA is added, and a second area to which data is written in shingled recording to write a plurality of tracks overlaid in a radial direction and to which an LBA is added, a plurality of heads, and a controller which writes data to the first area in the normal recording, writes data to the second area in the shingled recording, and changes the first area in accordance with a first recording capacity of a first recording surface in each of the disks, which corresponds to a first head of the heads, when the first head is inhibited from being used.

According to one embodiment, a magnetic disk device includes a disk including two first servo sectors and at least a second servo sector, a head, and a controller, wherein the first servo sector includes burst data and a first data pattern written before the circumferential direction of the burst data, the second servo sector includes the burst data, the first data pattern, and a second data pattern written after the circumferential direction of the burst data, a first frequency of the first data pattern is different from a second frequency of the second data pattern, and a first length of the first data pattern is different from a second length of the second data pattern.

A hard disk drive includes a magnetic writer and a magnetic recording medium, which includes data tracks with user data sections positioned between servo wedges. The servo wedges each can include multiple servo sectors. The hard disk drive also includes circuitry programmed to cause the magnetic writer to write user data to the multiple servo sectors in multiple servo wedges.