WO2008152541A1

WO2008152541A1 - A method for operating an optical drive

Info

Publication number: WO2008152541A1
Application number: PCT/IB2008/052177
Authority: WO
Inventors: Paulus T. A. Thijssen; Petrus J. H. J. Van Asten
Original assignee: Koninklijke Philips Electronics N.V.
Priority date: 2007-06-11
Filing date: 2008-06-04
Publication date: 2008-12-18
Also published as: TW200910331A

Abstract

The present invention relates to a method for robust operation of an optical drive for recording a data stream (AVS). The optical drive manages the data stream and the recording thereof with a real-time authoring system (RTA) having a corresponding recording database (RDB), the recording database comprising information related to a content directory of the carrier (TOC). At least a portion of the recording database (RDB') and recovery information (Rl, R2, R3) is recorded on the carrier, the recovery information being extracted from the recording database (RDB). In particular, the latest recorded recovery information (R3), in combination with the said portion of the recording database (RDB'), is sufficient for accessing at least the data stream (AVS) recorded until the latest recorded recovery information (R3). The invention facilitates robust operation of an optical drive because the effects of an unintended power failure of the optical drive have less impact. Intended interruption and disc recognition may also be performed faster.

Description

A METHOD FOR OPERATING AN OPTICAL DRIVE

FIELD OF THE INVENTION

The present invention relates to a method for operating an optical drive. The invention also relates to a corresponding optical carrier, a corresponding method for reproducing information from an optical carrier, a corresponding optical drive for implementing the invention, and a corresponding computer program.

BACKGROUND OF THE INVENTION

The application of optical recording and replaying of information stored on optical discs, such as CDs, DVDs, and recently BDs (Blu-Ray Disc), have become more and more widespread in areas ranging from entertainment, education, administration and even health care.

The time lapsed before replay of the data can be performed on a suitable optical drive is a concern for the user- friendliness. Upon insertion of an optical disc in a currently available optical drive, a range of initial procedures for disc recognition is performed which may last many seconds. Similarly, during optical recording of data on an optical carrier, the necessary fmalization of the recording process is a relevant time factor for the user- friendliness.

The reliability of the data stored on the optical disc has also been subject to an increasing consideration. Thus, various defect management schemes and methods are available in the art to handle defect on disc. Additionally, various methods for performing a recovery of the data and/or recording process after an unintended power failure of an optical drive are known.

WO 02/50829 (to the same applicant) discloses a power failure recovery method for an optical drive such as a DVD player. Recording indication information and a recovery pointer information is written in a non- volatile random access memory, while recovery information is recorded on a record carrier such as a recordable optical disc. At a power-up operation, the recording indication information is used to determine a power failure and the pointer information is used to reproduce the recovery information in case of a determined power failure. Thus, the pointer information indicates the location of incremental recovery data structures on the record carrier, such that a recovery can be achieved after a power failure without requiring a restart of the entire recording process.

However, it is necessary that the recording process is resumed on the same optical drive where the recording process was interrupted. It is also a requirement that the optical drive is adapted to record the pointer information at regular intervals.

Hence, an improved method for operating an optical drive would be advantageous, and in particular a more efficient and/or reliable method would be advantageous.

SUMMARY OF THE INVENTION

Accordingly, the invention preferably seeks to mitigate, alleviate or eliminate one or more of the above mentioned disadvantages singly or in any combination. In particular, it may be seen as an object of the present invention to provide a method for operating an optical drive that solves the above mentioned problems of the prior art with interruptions, both intended and/or un-intended interruptions.

This object and several other objects are obtained in a first aspect of the invention by providing a method for robust operation of an optical drive, the drive being adapted for recording optically detectable effects on an optical carrier, the method comprising: - providing a data stream (AVS) for recording on the carrier, managing the data stream and the recording thereof with a real-time authoring system (RTA), said system having a corresponding recording database (RDB), the recording database comprising information related to at least:

- a content directory of the carrier (TOC), - recording at least a portion of the recording database (RDB') on the optical carrier, recording the data stream on the optical carrier, and successively recording recovery information (Rl , R2, R3) on the carrier, the recovery information being extracted from the recording database (RDB), wherein the latest recorded recovery information (R3), in combination with the said portion of the recording database (RDB'), is sufficient for accessing at least the data stream (AVS) recorded until the latest recorded recovery information (R3). The invention is particularly, but not exclusively, advantageous for providing a method that facilitates robust operation of an optical drive, in particular for recording of information as optically readable effects, where the effects of an unintended power failure of the optical drive have less impact relative to the optical drives hitherto known in the art. In particular, the invention provides the possibility of reproducing or replaying the information stored until the latest recorded recovery information (R3) on an optical drive different from the optical drive where the unintended power failure occurred provided. As will be explained in more detail below, this requires only a minor modification of the optical drives and/or the optical carrier. In addition to the possibility of the improved replay after a power failure, the invention provides an opportunity for faster aborting the recording process. This can be envisioned as a controlled or intended variant of the power failure. Currently optical recording on optical carriers or optical discs comprises a time-consuming fmalization process where information about the recording process and/or the recorded information is recorded on the optical carrier. With the present invention, this fmalization process may be fully or partly omitted. Apart from the increased user- friendliness, this may also in some critical applications, e.g. within health care, save valuable time otherwise lost.

Yet another advantage provided by the present invention is the ability to perform faster recognition of the optical carrier or the optical disc than hitherto possible because of the portion of the recording database that is stored on the optical carrier itself. Previously, the recording database, or parts thereof, was generated from information read from various positions on the optical carrier using relative large amounts of time, which in turn deteriorate user-friendliness and, for critical applications in e.g. medical use, this can be highly counter-productive. Disc or carrier recognition is generally accepted in the field of optical recording to comprise two main processes: a process of determining what kind of disc is inserted by the user. It starts with determining the physical disc type (CD-ROM, CD-R, CD-RW, DVD-ROM, DVD+R, DVD+RW, DVD-R, DVD-RW, DVD-RAM, BD-ROM, BD-R, BD-RE etc.) This is done by the optical drive by well known methods and is outside the scope of the present invention, and a process for determining the logical format of the data (CD-DA, VCD, SVCD, DVD-video, DVD+VR etc.) and to read the appropriate structures and files as determined by the logical format in order to be able to start playback or recording what may be desired.

The present invention may have the additional advantage that for rewriteable (RW) optical carriers, portions of the carrier that are not yet overwritten may be accessible despite an unintended interruption of the over-writing process by application of the latest recorded recovery information (R3) in combination with the said portion of the recording database (RDB). Thus, this information may be retrieved anyway despite the interruption.

Beneficially, the recovery information (Rl, R2, R3) may be recorded on the optical carrier periodically, either in time, with respect to the physical address or the logical address. Additionally or alternatively, the recovery information (Rl, R2, R3) may be recorded in groups which are, at least partly, mutually redundant, e.g. the last M packs of recovery information may be recorded in N blocks, where M and N are integer values.

In one embodiment, the size of each recorded recovery information (Rl) may be maximum 2048 bytes, preferably maximum 1024 bytes, or more preferably maximum 512 bytes. Possibly, the size of the portion of the recording database (RDB') may be minimum 50 kbytes, preferably minimum 100 kbytes, or more preferably minimum 200 kbytes. Thus, typically the recorded recovery information (Rl) is substantially smaller than the portion of the recording database (RDB').

In another embodiment, the address of the latest recorded recovery information (R3) may be stored periodically on the optical carrier, either the physical address or the logical address. Alternatively or additionally, pointers to latest recorded recovery information (R3) can be stored, which saves time relative to prior art methods where VMGI is scattered on the disc.

Possibly, a recording session identity may be recorded with the portion of the recording database (RDB') and/or the corresponding recovery information (Rl, R2, R3) so as to allow for multi-session recording.

Preferably, the portion of the recording database (RDB') and/or the corresponding recovery information (Rl, R2, R3) may be recorded in non-standardized private areas. However, if the present invention becomes standardized this information can be stored in standardized areas.

In an embodiment, the recording database (RDB) may additionally comprise information related to at least one of: logical format of the optical carrier, e.g. CD-DA, VCD, SVCD, etc. general information about the specific optical carrier, for example VRMI (e.g. name) disc attributes, number of recordings and so forth. information related to recordings performed, e.g. chapters and cells, cell information, like for example ID and start address. - video object (VOBU) information, e.g. start address, and chapter information

Additionally or alternatively, the recorded portion of the recording database (RDB') may comprise information related to at least one of: - logical format of the optical carrier, e.g. CD-DA, VCD, SVCD, etc. general information about the specific optical carrier, for example VRMI (e.g. name) disc attributes, number of recordings and so forth. information related to recordings performed, e.g. chapters and cells, cell information, like for example ID and start address. - video object (VOBU) information, e.g. start address, chapter information, and a content directory of the carrier (TOC),

The method according to the present invention may further comprise the recording of an executable application (EXE) capable of reading the portion of the recording database (RDB') and the corresponding recovery information (Rl, R2, R3). Possibly, the executable application may enable reproducing of the recorded datastream (AVS) from the carrier, e.g. devices that may run the application, such as a personal computer (PC).

Possibly, the executable application (EXE) may enable transforming the format of the optical carrier into a standardized format. Thus, the format may be transformed from a non-standard to a standard format with the said application.

In one embodiment, the data stream of the optical carrier may be accessible until the latest recorded recovery information (R3) despite an abrupt interruption in the recording process. Possibly, the abrupt interruption in the recording process may be caused by a power failure of the optical drive. Alternatively, the abrupt interruption in the recording process may be caused by a request for ejection of the optical carrier from the optical drive, a stand-by request or a stop request; preferably the requests are being user- initiated. If a user initiated stop request is performed the optical drive may still have sufficient time for recording the latest recorded recovery information (R3). In another embodiment, the portion of the recording database (RDB') may enable recognition of the optical carrier. Thus, the file system or the entire recording database (RDB) does not have to be built saving up till 10 seconds of time for the user. It could still be necessary to determine disc type, but determining logical format by reading scattered data on the carrier is not needed.

In a second aspect, the invention relates to an optical drive, the drive being adapted for recording optically detectable effects on an associated optical carrier, the drive comprises: processing means for providing a data stream for recording on the carrier, - processing means for managing the data stream and the recording thereof with a real-time authoring system (RTA), said system having a corresponding recording database (RDB), the recording database comprising information related to at least: - a content directory of the carrier, recording means for recording at least a portion of the recording database (RDB') on the optical carrier, and recording means for recording the data stream on the optical carrier, and successively recording recovery information (Rl , R2, R3) on the carrier, the recovery information being extracted from the recording database (RDB), wherein the latest recorded recovery information (R3), in combination with the said portion of the recording database (RDB'), is sufficient for accessing at least the data stream recorded until the latest recorded recovery information (R3).

Beneficially, the optical drive may comprise an application (EXE) that enables reproducing of the recorded datastream (AVS) from the carrier. Thus, the optical drive can be said to be a so-called "RDB-aware" optical recording/replaying device. In a third aspect, the invention relates to an optical carrier being adapted for recording optically detectable effects, the carrier being arranged for recording a data stream by an associated optical drive, the drive being adapted for managing the data stream and the recording thereof with a real-time authoring system (RTA), said system having a corresponding recording database (RDB), the recording database comprising information related to at least a content directory of the carrier, the carrier comprising and/or being adapted for having recorded thereon: at least a portion of the recording database (RDB') on the optical carrier, the data stream on the optical carrier, and recovery information (Rl, R2, R3) successively recorded on the carrier, the recovery information being extracted from the recording database (RDB), wherein the latest recorded recovery information (R3), in combination with the said portion of the recording database (RDB'), is sufficient for accessing at least the data stream recorded until the latest recorded recovery information (R3).

In a fourth aspect, the invention relates to a method for reproducing information from an optical carrier by an optical drive, the drive being adapted for reproducing optically detectable effects on an optical carrier, the carrier comprising: at least a portion of a recording database (RDB') on the optical carrier, - a data stream on the optical carrier, and recovery information (Rl, R2, R3) successively recorded on the carrier, the recovery information being extracted from a recording database (RDB), the method comprising reproduction of the latest recorded recovery information (R3), and in combination with the said portion of the recording database (RDB'), which is sufficient for accessing at least the data stream recorded until the latest recorded recovery information (R3).

In a fifth aspect, the invention relates to a computer program product being adapted to enable a computer system comprising at least one computer having data storage means associated therewith to control an optical drive according to the first and/or fourth aspect of the invention.

This aspect of the invention is particularly, but not exclusively, advantageous in that the present invention may be implemented by a computer program product enabling a computer system to perform the operations of the second aspect of the invention. Thus, it is contemplated that some known optical drive may be changed to operate according to the present invention by installing a computer program product on a computer system controlling the said optical drive. Such a computer program product may be provided on any kind of computer readable medium, e.g. magnetically or optically based medium, or through a computer based network, e.g. the Internet.

The first, second, third, fourth and fifth aspect of the present invention may each be combined with any of the other aspects. These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will now be explained, by way of example only, with reference to the accompanying Figures, where

Figure 1 is schematic drawing of an optical drive according to the present invention, Figure 2 is a schematic flow chart for the real-time authoring system (RTA) according to the present invention,

Figure 3 is a schematic flow chart for the generation of the recording database (RDB) during a recording session,

Figure 4 is a schematic drawing of the logical format of the optical carrier according the present invention,

Figure 5 is schematic drawing of video objection unit (VOBU) in the logical format of the optical carrier according the present invention,

Figure 6 is a flow chart for operating an optical drive according to the present invention, and Figure 7 is a schematic drawing of embodiment of the logical format of the optical carrier according the present invention, and

DETAILED DESCRIPTION OF AN EMBODIMENT

Figure 1 is schematic drawing of an optical drive according to the present invention.

The drive is provided with recording means for scanning the track on the optical carrier or disc 1, the recording means comprising a drive unit 16 for rotating the optical disc 1, an optical pick-up unit OPU, a positioning unit 21 for coarsely positioning the OPU in the radial direction on the track, and a control unit 11, e.g. a central processing unit (CPU). The optical pick-up unit OPU comprises an optical system of a known type for generating a radiation beam 20 guided through optical elements for focusing said radiation beam 20 to a radiation spot on the track of the optical disc 1. The radiation beam 20 is generated by a radiation source, e.g. a laser diode. The OPU further comprises (not shown) a focusing actuator for moving the focus of the radiation beam 20 along the optical axis of said beam and a tracking actuator for fine positioning of the radiation spot 19 in a radial direction on the centre of the track. The tracking actuator may comprise coils for radially moving an optical element and/or may alternatively be arranged for changing the angle of a reflecting element. For reading information, the radiation reflected by the information layer is detected by a detector of a usual type, e.g. a four-quadrant diode, in the OPU for generating a read signal and further detector signals, such as a tracking error (TE) and a focusing error (FE) signal for controlling said tracking and focusing actuators. The read signal is processed by a read processing unit comprising a demodulator 26, a de-formatter 27 and output unit 28 for outputting the information. The functioning of the demodulator 26, the de-formatter 27 and the output unit 28 is controlled by the controller 11. Hence, retrieving means for reading information include the drive unit 16, the head 18, the positioning unit 21 and the read processing unit. The retrieved information 60 is finally outputted from the unit 11. For recording information, the radiation beam 20 is controlled to create optically detectable marks in the recording layer. For this purpose, the recording device comprises write processing means for processing input information to generate a write signal to drive the OPU, which write processing means comprise an input unit 23; and data processing means comprising a formatter 24 and a modulator 25. The control unit 11 controls the recording and retrieving of information 61 onto and from the optical disc 1 , and may be arranged for receiving commands from a user or from a host computer. To this end, the control unit 11 may comprise control circuitry, for example a microprocessor, a program memory and control gates, thereby constituting suitable means for performing the procedures described hereinafter with reference to Figs. 2- 7. The control unit 11 may also be implemented as a state machine in logic circuits. The control unit 11 is connected via control lines, e.g. a system bus, to said input unit 23, formatter 24 and modulator 25, to the drive unit 16, and to the positioning unit 21.

The input unit 23 receives and pre-processes the user information. For example, when processing audio-video information, the input unit 23, may comprise compression means for compressing input signals such as analog audio and/or video, or digital uncompressed audio/video. Suitable compression means are described for audio in WO 98/16014-A1, and for video in the MPEG2 standard (ISO-IEC 13818). The input signal may alternatively be already encoded. The output of the input unit 23 is passed to the formatter 24 for adding control data and formatting the data according to a recording format, e.g. by adding error correction codes (ECC) and/or interleaving. For computer applications units of information may be interfaced to the formatter 24 directly. The formatted data from the output of the formatter 24 is passed to the modulation unit 25, which comprises for example a channel coder, for generating a modulated signal. Further the modulation unit 25 comprises synchronizing means for including synchronizing patterns in the modulated signal. The formatted units presented to the input of the modulation unit 25 comprise address information and are written to corresponding addressable locations on the optical disc under the control of control unit 11. The control unit 11 is further arranged for recording and retrieving position data indicative of the position of the recorded information volumes. During the recording operation, marks representing the information are formed on the optical disc. The marks may be in any optically readable form, e.g. in the form of areas with a reflection coefficient different from their surroundings, obtained when recording in materials such as dye, alloy or phase change material, or in the form of areas with a direction of magnetization different from their surroundings, obtained when recording in magneto- optical material. Writing and reading of information for recording on optical carrier or optical disks and usable formatting, error correcting and channel coding rules are well-known in the art, e.g. from the CD system (IEC 908).

Figure 2 is a schematic flow chart for the real-time authoring system RTA according to the present invention. The Figure gives an over- view of the RTA for controlling the conversion of audio/video signals entering the system and the processing of the signal into e.g. a compressed multiplexed signal for recording on the optical carrier 1. The control unit 11, the audio/video encoders ENC 31 and the multiplexer MUX 32 are controlled and communicate with the real-time authoring system RTA so as to generate a compliant program stream with the relevant standard, e.g. DVD(+RW). Furthermore, the RTA is responsible for maintaining the overall meta-data and creating the disc menu for e.g. the DVD(+RW) disc. The real-time authoring system RTA maintains an internal structure, the so-called recording database RDB, from which the RTA generates the meta-data and creates the disc menu. The RTA can be embedded within the control unit 11 or on a separate control unit (not shown). Figure 3 is a schematic flow chart for the generation of the recording database

RDB during a recording session as performed hitherto i.e. before the present invention. When a disc 1 is inserted INSERT 1, first the RDB is generated from the file system, the VRMI, and the VTSI FS ->RDB. Following that the system will play back, PLAY, from the RDB (for efficiency reasons). When a record command REC is given, the system starts recording. While recording, the RDB is updated in real-time Upd RDB. For that purpose, RTA uses notifications from the encoder and multiplexer components and other components/units as shown in Figure 2. Typical notifications are related to or comprise audio/video properties, bit rate information, group of pictures (GOP)/Cell/ video object unit (VOBU) boundaries, etc. When recording is finished, a new disc menu and a new file system, a new VRMI, and a new VTSI are created from the RDB, step RDB->FS. However, when a power failure or other unintended interruption occurs after recording has started and before the disc menu and the file system, the VRMI, and VTSI FS have been updated, the disc 1 becomes corrupt.

Many different embodiments of the recording database RDB for supporting the real-time authoring system RTA are possible within the teaching of the present invention. Below are given a non-exhaustive list of information that can be organized and/or stored in the recording database RDB. Note that all terminology used below comes from the DVD- video and DVD+VR standards (DVD+VR is the logical video recording format for DVD+R(W) media) and is therefore common for a person skilled in the art. The teaching of the present invention is however not limited to this standard, but can readily be extended to other standards, currents as well as future standards.

The term "recording database" RDB has not yet reached a generally accepted definition in the field of optical recording, though the skilled person, upon reading of the present application and the teaching derived there from, can readily understand the concept of the recording database RDB.

The RDB contains sufficient information to generate all relevant content directory information that is prescribed by the applicable optical disc standard. In the case of DVD+VR this comprises the (ISO and/or UDF) file system, video manager general information (VMGI), video title set information (VTSI), and video recording manager information (VRMI).

The RDB could be organized as follows:

Containing information of a single disc, and

File system information

Disc information could be organized as follows:

Disc attributes,

General part of the VRMI (e.g. disc name), and A number of recordings

Recording information could be organized as follows:

Recording attributes, e.g. title name, channel name, recording mode, resolution, video system, audio type(s), audio stream mapping, recording start address, recording end address,

A number of chapters, A number of VR chapters, and A number of Cells

Cell information could be organized as follows: - Cell attributes,

Cell ID, Cell start address, Cell end address, seamless flag, and A number of VOBU' s.

VOBU information could be organized as follows: - VOBU start address.

Chapter information could be organized as follows: Reference to a Cell that marks the beginning of a chapter, and Flag indicating whether or not it should be played in the playlist.

VR chapter information could be organized as follows: Reference to a VOBU that marks the beginning of that VR chapter, and Flag indicating whether or not it should be played in the edit decision list (EDL).

File system information could be organized as follows: A number of files that is present.

File information could be organized as follows: - Start address, and

Size.

In one embodiment, the portion of the recording database RDB' stored on the optical disc 1 can especially be identical to the recording database RDB used by the real-time authoring system RTA. In other embodiments, the portion of the recording database RDB' stored on the optical disc 1 can be a subset or a fraction of the recording database RDB used by the real-time authoring system RTA as long as the reduced recording database RDB' complies with the functionality that the latest recorded recovery information R3, in combination with the said portion of the recording database RDB', is sufficient for accessing the data stream 61 AVS recorded until the latest recorded recovery information R3.

Figure 4 is a schematic drawing of the logical format of the optical carrier 1 according the present invention. The optical disc 1 is intended for carrying user information according to a recording format, and to be playable on standardized playback devices. The recording format includes the way information is recorded, encoded and logically mapped onto the recording area provided by the track and it will be described, by way of example, with reference to Figure 4.

The recordable area is usually subdivided into a lead-in area LI, a data zone DZ for recording the information, and a lead-out area LO. The lead-in area LI usually comprises basic disc management information and information on how to physically access the data zone DZ, i.e. mapping the recordable area to a logical recording space, and logical sectors to physical sectors. For example, said basic disc management information corresponds to the table of contents in CD systems or the formatting disc control blocks (FDCB) in DVD systems.

The user information recorded in the data zone DZ is further arranged according to a logical format, for example comprising a predefined structure of files and directories. For example, the data zone DZ can comprise a first data zone DZl and a DVD video zone DVD-VZ, wherein the latter comprises one or more video title set VTS n. Further, at logical level, the user data in the data zone is arranged according to a file system comprising file management information, such as ISO 9660 used in CD systems, available as ECMA-119, or UDF used in DVD systems, available as ECMA- 167. Such file management information is mapped on a predefined location on the optical disc 11 , usually in or directly after the lead-in area LI. The user information recorded in the data zone DZ may be further arranged according to a recording format, for example comprising a predefined structure of files and directories.

In the embodiment of Figure 4, the logical format is illustrated in the case of recording video information and user data onto a DVD+RW disc. The first data section DZl comprises a video file system FS, a portion of the recording database RDB' in a so-called scratch area, a Video Recorder Manager Information VRMI, and a Video Recorder Manager User Data VRM UD. Next to the first data section DZl, a DVD Video Zone DVD-VZ is located. The indicated sections need not be recorded contiguously as shown in Figure 4. The RDB' is stored in a scratch area which is an area used by recorders to temporally store data. The Video Recorder Manager Information VRMI comprises information with respect for identifying the type of recorder that has generated the DVD-Video menus on the disc 1. The Video Recorder Manager Information VRMI further comprises information whether a data section is present on the disc. The Video Recorder Manager User Data VRM UD are optional data structures that may be stored in one or more files, which may be recorded to add functionality and to improve performance on some recorders.

The DVD video zone DVD-VZ comprises one or more video title set VTS n, where each video title set VTS_ comprises a plurality of video object units VOBU i as schematically indicated in the right-hand portion of Figure 4. One VOBU typically comprises 0.4 to 1 second of playback time and consists of a number of video cells, each video cell comprising a plurality of GOPs (Group of Pictures). A movie story can be defined as a sequence of chapters.

Figure 5 is schematic drawing of a video objection unit VOBU i in the logical format of the optical carrier according the present invention, where each video cell Cl, C2, and C3 has a corresponding recovery sector Rl, R2, and R3, respectively. For illustrative purpose only three cells and recovery sectors are drawn, but in practice there is no limit to the number of recovery sectors that can be used. As indicated in Figure 5, each of the recovery sectors is multiplexed in the recording data stream after the corresponding cell has been written to the stream. However, there is no particular requirement regarding the actual location of the recovery sector with respect to the corresponding cell. In practice, the recovery sector is preferably written next to the corresponding cell to minimize the number of seek operations performed by the optical drive. It should be noted that a recording overhead is generated by the present invention, but this overhead is usually relatively low or negligible, both with respect to amount of space on the carrier 1 and with respect to the time spent on writing the recovery sectors Rl, R2, and R3. The procedures for the recovery sectors can be similar to the teaching of WO 02/50829 (to the same applicant), which is therefore incorporated by reference in its entirety.

Figure 6 is a flow chart for operating an optical drive according to the present invention. Upon insertion of an optical carrier or disc 1 into the optical drive, INS 1, the optical drive will during a start-up procedure read the portion of the recording database RDB' stored on the optical carrier 1. If the last performed recording operation performed on the optical carrier 1 was successfully finalized i.e. without interruption, the portion of the recording database RDB' comprises information of the successful recording, e.g. a recording successful flag/indicator can be stored. If this information is present, a decision can be made at the step INTRP?, that no interruption occurred during the last recording and that normal replaying and/or normal recording of information can take place or be resumed as indicated by the step PLAY/REC.

If the portion of the recording database RDB' does not comprise information of a previous successfully recording action, the decision is taken that an interruption has occurred in the step INTRPT? Accordingly, the latest stored recovery information R3 is found, preferably RDB' can comprises pointers to R3, and in combination with the RDB' information can be replayed from the optical carrier 1 and/or recording operations can be resumed on the optical carrier 1.

The portion of the recording database RDB' also enables fast disc recognition during the start-up procedure due to the reduced, possible even obviated, need for performing seek and read operations to determine the logical format of the optical carrier 1. Estimations and preliminary tests performed indicate that several seconds, possibly up to 10 seconds, can be saved by the present invention. Thus, user-friendliness is improved and it opens for applications with critical purposes where speed and/or reliability are key factors, such as medical applications and within security sectors.

The present invention further facilitate fast eject of the optical carrier 1 from the optical drive during a recording operation. In this respect, a fast eject process, preferably initiated by a user-operation, can be considered as intended interruption of a recording process i.e. the net result with respect to the optical carrier is the same: no successful recording flag is stored in RDB', but due to the teaching of the present invention the carrier is not corrupted and information can be replayed and recorded nevertheless.

Figure 7 is a schematic drawing of embodiment of the logical format of the optical carrier 1 according the present invention showing the first data zone DZl, cf. Figure 1. In this embodiment, an executable application EXE (indicated by an arrow) is stored on the optical carrier 1 , and the application EXE enables the optical drive to read the reduced recording database RDB' and thereby enables reproducing of the recorded data stream (AVS) from the carrier 1.

After running EXE, the optical drive can for example play back the AVS data stream directly. Alternatively or additionally, the EXE program can transform the carrier or disc 1 into e.g. a regular DVD(+RW) disc (i.e. menu creation, file system update, etc.). The target operative system (OS) for such the executable EXE may be Windows, MacOS, (preferably, multiple applications may be stored serving different operation systems).

This leads to the following different three classes or kinds of optical drives for different implementations of the invention: 1. Optical drives that are capable of performing fast disc recognition and fast title recording fmalization by writing RDB' and EXE on disc, and possibly subsequent reading of the RDB' and EXE again after an interruption.

2. Optical drives capable of reading and executing EXE followed by playback of the AVS and/or transformation of the format into a regular standardized format. This can the case e.g. in connection with optical drives for personal computers (PC).

3. Optical drives that cannot recognize the disc 1 despite the portion of the recording database RDB' and the application EXE stored on the disc. A standard DVD menu can be recorded informing the user of the deficiency (e.g. initially a user message "Disc needs to be finalized" can be shown).

The invention can be implemented in any suitable form including hardware, software, firmware or any combination of these. The invention or some features of the invention can be implemented as computer software running on one or more data processors and/or digital signal processors. The elements and components of an embodiment of the invention may be physically, functionally and logically implemented in any suitable way. Indeed, the functionality may be implemented in a single unit, in a plurality of units or as part of other functional units. As such, the invention may be implemented in a single unit, or may be physically and functionally distributed between different units and processors. Although the present invention has been described in connection with the specified embodiments, it is not intended to be limited to the specific form set forth herein. Rather, the scope of the present invention is limited only by the accompanying claims. In the claims, the term "comprising" does not exclude the presence of other elements or steps. Additionally, although individual features may be included in different claims, these may possibly be advantageously combined, and the inclusion in different claims does not imply that a combination of features is not feasible and/or advantageous. In addition, singular references do not exclude a plurality. Thus, references to "a", "an", "first", "second" etc. do not preclude a plurality. Furthermore, reference signs in the claims shall not be construed as limiting the scope.

Claims

CLAIMS:

1. A method for robust operation of an optical drive, the drive being adapted for recording optically detectable effects on an optical carrier (1), the method comprising: providing a data stream (AVS) for recording on the carrier, managing the data stream and the recording thereof with a real-time authoring system (RTA), said system having a corresponding recording database (RDB), the recording database comprising information related to at least:

- a content directory of the carrier (TOC), recording at least a portion of the recording database (RDB') on the optical carrier, - recording the data stream on the optical carrier, and successively recording recovery information (Rl , R2, R3) on the carrier, the recovery information being extracted from the recording database (RDB), wherein the latest recorded recovery information (R3), in combination with the said portion of the recording database (RDB'), is sufficient for accessing at least the data stream (AVS) recorded until the latest recorded recovery information (R3).

2. The method according to claim 1, wherein the recovery information (Rl, R2, R3) is recorded on the optical carrier periodically.

3. The method according to claim 1, wherein the recovery information (Rl, R2,

R3) is recorded in groups which are, at least partly, mutually redundant.

4. The method according to claim 1, wherein the size of each recorded recovery information (Rl) is maximum 2048 bytes, preferably maximum 1024 bytes, or more preferably maximum 512 bytes.

5. The method according to claim 1 or 4, wherein the size of the portion of the recording database (RDB') is minimum 50 kbytes, preferably minimum 100 kbytes, or more preferably minimum 200 kbytes.

6. The method according to claim 1, wherein the address of the latest recorded recovery information (R3) is stored periodically on the optical carrier (1).

7. The method according to claim 1, wherein a recording session identity is recorded with the portion of the recording database (RDB') and/or the corresponding recovery information (Rl, R2, R3).

8. The method according to claim 1, wherein the portion of the recording database (RDB') and/or the corresponding recovery information (Rl, R2, R3) is recorded in non-standardized private areas (SCR).

9. The method according to claim 1, wherein the recording database (RDB) additionally comprises information related to at least one of: - logical format of the optical carrier (1), general information about the specific optical carrier, information related to recordings performed, cell information, video object (VOBU) information, and - chapter information.

10. The method according to claim 1, wherein the recorded portion of the recording database (RDB') comprises information related to at least one of: logical format of the optical carrier (1), - general information about the specific optical carrier, information related to recordings performed, cell information, video object (VOBU) information, chapter information, and - a content directory of the carrier (TOC),

11. The method according to claim 1 further comprising the recording of an executable application (EXE) capable of reading the portion of the recording database (RDB') and the corresponding recovery information (Rl, R2, R3).

12. The method according to claim 11, wherein the executable application enables reproducing of the recorded datastream (AVS) from the carrier (1).

13. The method according to claim 11, wherein the executable application enables transforming the format of the optical carrier (1) into a standardized format.

14. The method according to claim 1, wherein the data stream (AVS) of the optical carrier is accessible until the latest recorded recovery information (R3) despite an abrupt interruption in the recording process.

15. The method according to claim 14, wherein the abrupt interruption in the recording process is caused by a power failure of the optical drive.

16. The method according to claim 14, wherein the abrupt interruption in the recording process is caused by a request for ejection of the optical carrier (1) from the optical drive, a stand-by request or a stop request, preferably the request(s) is(are) being user- initiated.

17. The method according to claim 1, wherein the portion of the recording database (RDB') enables recognition of the optical carrier (1).

18. An optical drive, the drive being adapted for recording optically detectable effects on an associated optical carrier (1), the drive comprises: - processing means (11, 23, 24, 25, 31, 32) for providing a data stream (AVS,

61) for recording on the carrier, processing means (11, 23, 24, 25, 31, 32) for managing the data stream and the recording thereof with a real-time authoring system (RTA), said system having a corresponding recording database (RDB), the recording database comprising information related to at least:

- a content directory of the carrier (TOC), recording means (20, 21, OPU) for recording at least a portion of the recording database (RDB') on the optical carrier, and recording means (20, 21, OPU)for recording the data stream on the optical carrier, and successively recording recovery information (Rl, R2, R3) on the carrier, the recovery information being extracted from the recording database (RDB), wherein the latest recorded recovery information (R3), in combination with the said portion of the recording database (RDB'), is sufficient for accessing at least the data stream (AVS) recorded until the latest recorded recovery information (R3).

19. An optical drive according to claim 18, the optical drive comprising an application (EXE) that enables reproducing of the recorded datastream (AVS) from the carrier.

20. An optical carrier (1) being adapted for recording optically detectable effects, the carrier being arranged for recording a data stream (AVS) by an associated optical drive, the drive being adapted for managing the data stream and the recording thereof with a realtime authoring system (RTA), said system having a corresponding recording database (RDB), the recording database comprising information related to at least a content directory of the carrier (TOC), the carrier comprising and/or being adapted for having recorded thereon: at least a portion of the recording database (RDB') on the optical carrier, the data stream on the optical carrier, and - recovery information (Rl, R2, R3) successively recorded on the carrier, the recovery information being extracted from the recording database (RDB), wherein the latest recorded recovery information (R3), in combination with the said portion of the recording database (RDB'), is sufficient for accessing at least the data stream (AVS) recorded until the latest recorded recovery information (R3).

21. A method for reproducing information from an optical carrier by an optical drive, the drive being adapted for reproducing optically detectable effects on an optical carrier, the carrier comprising: at least a portion of a recording database (RDB') on the optical carrier, - a data stream on the optical carrier, and recovery information (Rl, R2, R3) successively recorded on the carrier, the recovery information being extracted from a recording database (RDB), the method comprising reproduction of the latest recorded recovery information (R3), which, in combination with the said portion of the recording database (RDB'), is sufficient for accessing at least the data stream (AVS) recorded until the latest recorded recovery information (R3).

22. A computer program product being adapted to enable a computer system comprising at least one computer having data storage means associated therewith to control an optical drive according to claim 1 or 21.