Abstract: A visible pattern is obtained by modulating the digital sum value. Because the digital sum value modulation allows the choice of several different channel bits groups between DC control points, the selection of a group of channel bits resulting in a change of reflection. This creation of a visible pattern is highly suitable for Blueray as the parity preserving property of the channel code guarantees disparity inversion by the DC-control bit, which keeps the DSV excursions between hard limits. As a result only small DSV deliberate variations are required to produce a grating, which will not deteriorate the bit-detection margin of the optical disc.

Abstract: A visible pattern is obtained by modulating the digital sum value. Because the digital sum value modulation allows the choice of several different channel bits groups between DC control points, the selection of a group of channel bits resulting in a change of reflection. This creation of a visible pattern is highly suitable for Blueray as the parity preserving property of the channel code guarantees disparity inversion by the DC-control bit, which keeps the DSV excursions between hard limits. As a result only small DSV deliberate variations are required to produce a visual watermark, which will not deteriorate the bit-detection margin of the optical disc.

Abstract: The present invention provides an error correcting method and apparatus for correcting errors in content. In accordance with a method embodiment, a method is provided for correcting errors in content, comprising, determining the types of the errors; sending a download request over a network for downloading error correcting information according to the type of the errors; receiving the error correcting information from the server; and correcting errors with the correcting information.

Abstract: A visible pattern is obtained by modulating the digital sum value. Because the digital sum value modulation allows the choice of several different channel bits groups between DC control points, the selection of a group of channel bits resulting in a change of reflection. This creation of a visible pattern is highly suitable for Blueray as the parity preserving property of the channel code guarantees disparity inversion by the DC-control bit, which keeps the DSV excursions between hard limits. As a result only small DSV deliberate variations are required to produce a grating, which will not deteriorate the bit-detection margin of the optical disc.

Abstract: An optical record carrier (30) comprising a plurality of information layers formed above a first surface of a substrate wherein at least one of the information layers is a re-writable cache layer is disclosed. The data that is read more than once is copied on to the re-writable cache layer when the recording/reproducing device is not in active use. Next time when the same data is requested, it can be read from the re-writable cache layer. This is advantageous since the data is stored un-fragmented on the re-writable cache layer and the re-writable cache layer can have higher read speeds than the other information layers in the optical record carrier. Therefore, the re-writable cache layer can improve the system performance in terms of read speed.

Abstract: A method (400) comprising recording content on at least one of a plurality of recording layers on an optical record carrier by means of a focused radiation beam, wherein the selection of the recording layer for recording the content is based on at least one of the following recording criteria: —characteristics of the content; —properties of the plurality of recording layers; —manual selection by an end user; and —automatic selection is disclosed. The method is useful for recording content on multi-layer optical discs such as DVD and Blu-raydiscs.

Abstract: A visible pattern is obtained by modulating the digital sum value. Because the digital sum value modulation allows the choice of several different channel bits groups between DC control points, the selection of a group of channel bits resulting in a change of reflection. This creation of a visible pattern is highly suitable for Blueray as the parity preserving property of the channel code guarantees disparity inversion by the DC-control bit, which keeps the DSV excursions between hard limits. As a result only small DSV deliberate variations are required to produce a visual watermark, which will not deteriorate the bit-detection margin of the optical disc.

Abstract: Buffering of a video stream containing intra frames (I-frames) and inter frames (P-frames, B-frames) is disclosed. A buffer memory is segmented in two parts, a contiguous part for buffering of contiguous frames of the video stream (I-, P- and B-frames), and an intra part for the buffering of intra frames of the video stream.

Abstract: A method for reading data from a track (3) of a data carrier (2) comprises the following steps. During reading, a tracking quality parameter (Q) is determined, relating to a track portion (3Px) of the data carrier from which the data is being read. The tracking quality parameter is stored in a tracking performance memory (30) in relation to the corresponding track portion (3Px). If a jump back to a previously read track portion appears to be necessary, said tracking performance memory (30) is consulted to determine a target track portion (3P(x-n)) having a sufficient value of the tracking quality parameter (Q); then, a jump back (JB) to the target track portion (3P(x-n)) thus determined is performed.

Abstract: In the field of content distribution a typical problem is the protection of Digital Rights information (DRM), which is appended to the content and recorded on a record carrier in the form of a corresponding recorded pattern, from tampering by malicious users. According to some known schemes, the protection is implemented by linking the DRM to some physical distinctive feature of the corresponding recorded pattern. From this distinctive feature fingerprint data can be extracted with some conventional method, and used for the authentication of the DRM. The invention proposes a method of recording data wherein variations in the density of the recorded pattern are formed, as result of a perturbation in the recording process, which is a non-controllable substantially random process.

Abstract: A radial tracking method for an optical information carrier format with non-uniformly spaced tracks is disclosed, wherein a plurality of tracks (21, 22, 23) are spaced apart at a track pitch TP2, respectively, within a broad spiral (20) having a track pitch TP, in an information layer of an optical information carrier. One central high intensity spot (25) and a plurality of symmetrically placed satellite spots (26, 27) are used for generating a tracking signal for said broad spiral (20). According to an embodiment, the push-pull signal is used for this purpose, resulting in a robust tracking signal. Further, unique address information is retrieved from each of the individual tracks within this broad spiral from a wobble of said tracks. As a result, higher storage densities are achieved, as the method enables tracking of narrowly spaced sub-tracks in a broad spiral that was previously not possible.

Abstract: A recording system stores files on a removable, optical record carrier (11). The record carrier has an annular recording area corresponding to a logical data space accessible according to a predefined recording format. The recording system has a control unit (20) for controlling the recording means for storing the files in respective data blocks. A backup unit (32) stores at least one backup file of an original file, and assigns, to the backup file, backup blocks in the logical data space. The backup blocks (305,306,307) are physically positioned remote from corresponding original blocks (302,303,304) of the original file in the logical data space, e.g. by applying a predetermined radial shift. Hence the record carrier is provided with reliable data, wherein the backup blocks and the original blocks form a spatially distributed pattern for avoiding that local disturbances of the recording area affect corresponding blocks of the original blocks and backup blocks.