To read data from a storage medium, a magnetization map of the data stored on at least one portion of the storage medium is obtained. The magnetization map is analyzed to obtain intermediate data corresponding to the data stored on the at least one portion of storage medium. Further, the intermediate data is converted into the user data based on format emulation of a data storage format of the storage medium. The conversion of the intermediate data includes decrypting the intermediate data to obtain the user data.

In a multilayer optical disc having information layers conforming to a plurality of different optical disc standards, because the type of each information layer is not recorded in the other information layers, in read and write operations by a compatible optical disc device conforming to a plurality of optical disc standards, every time the information layer being accessed changes, it has been necessary to read the type of the information layer and select a method of generating a tracking error signal adapted to the type of information layer, so access has taken time. In order to solve the above problem, in the optical multilayer disc according to the present invention, having information layers conforming to a plurality of different optical disc standards, in an area in one of the information layers, information about the other information layers is recorded. The time required to access the other information layers can be reduced by using this information to select a tracking error signal generating method.

.[.A method is disclosed that includes: receiving, via a network digital video recorder, a request to record requested content; receiving, via a network digital video recorder at a first time, the requested content in a first format and the requested content in a second format; storing, via the network digital video recorder, the requested content in the first format; storing, via the network digital video recorder, the requested content in the second format; deleting, from network digital video recorder, the requested content in the second format after a predetermined time period; and transcoding, via an on demand transcoder, the requested content in the first format to the requested content in a third format after the predetermined time period..]. .Iadd.A method is disclosed, including: receiving request to record content; receiving the requested content in a plurality of versions; storing the requested content; from the plurality of versions, identify mezzanine content having a first format and resolution for retaining in storage; for a remaining plurality of versions: determine at least one criterion; retain one or more versions of the remaining plurality of versions in storage until the at least one criterion is met; receiving a request for playback of the requested content to a subscriber's device; determining whether the request may be fulfilled using any stored versions of the plurality of versions of the requested content; if the version having a format and resolution corresponding to the decoding capabilities of the subscriber's device is not stored, regenerate, from a stored version of the plurality of versions, the format and resolution that corresponds to the decoding capabilities of the subscriber's device..Iaddend.

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 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 play back device includes a readout unit and a playback unit. The readout unit reads out an encoded main video stream and an encoded sub-video stream that are recorded in a recording medium. The sub-video stream is a sub-video that is to be superimposed on the main video and displayed. The playback unit plays the main video stream and the sub-video stream that have been read out. The sub-video stream includes multiple sets, each set including a first sub-video stream for a first luminance dynamic range and a second sub-video stream for a second luminance dynamic range, which is wider than the first luminance dynamic range. In the same set in the multiple sets, a registration order of the first sub-video stream in the first database and a registration order of the second sub-video stream in the second database are the same.

In a multilayer optical disc having information layers conforming to a plurality of different optical disc standards, because the type of each information layer is not recorded in the other information layers, in read and write operations by a compatible optical disc device conforming to a plurality of optical disc standards, every time the information layer being accessed changes, it has been necessary to read the type of the information layer and select a method of generating a tracking error signal adapted to the type of information layer, so access has taken time. In order to solve the above problem, in the optical multilayer disc according to the present invention, having information layers conforming to a plurality of different optical disc standards, in an area in one of the information layers, information about the other information layers is recorded. The time required to access the other information layers can be reduced by using this information to select a tracking error signal generating method.

A plurality of kinds of LPCM signals/compression digital audio signals is switched to one another in transmission, thereby enabling audio reproduction to be satisfactorily carried out. A digital audio signal is transmitted to an external apparatus through a predetermined transmission path. Information associated with the digital audio signal to be next transmitted is added to the digital audio signal which is currently being transmitted. For example, first metadata exhibiting a transmission frequency of the digital audio signal, and second metadata exhibiting a data type of the digital audio signal are contained in the information.

A play back device includes a readout unit and a playback unit. The readout unit reads out an encoded main video stream and an encoded sub-video stream that are recorded in a recording medium. The sub-video stream is a sub-video that is to be superimposed on the main video and displayed. The playback unit plays the main video stream and the sub-video stream that have been read out. The sub-video stream includes multiple sets, each set including a first sub-video stream for a first luminance dynamic range and a second sub-video stream for a second luminance dynamic range, which is wider than the first luminance dynamic range. In the same set in the multiple sets, a registration order of the first sub-video stream in the first database and a registration order of the second sub-video stream in the second database are the same.

In a multilayer optical disc having information layers conforming to a plurality of different optical disc standards, because the type of each information layer is not recorded in the other information layers, in read and write operations by a compatible optical disc device conforming to a plurality of optical disc standards, every time the information layer being accessed changes, it has been necessary to read the type of the information layer and select a method of generating a tracking error signal adapted to the type of information layer, so access has taken time. In order to solve the above problem, in the optical multilayer disc according to the present invention, having information layers conforming to a plurality of different optical disc standards, in an area in one of the information layers, information about the other information layers is recorded. The time required to access the other information layers can be reduced by using this information to select a tracking error signal generating method.