Information recording medium and system controller

An information recording medium for recording a real-time file containing real-time data in such a manner that the real-time data is continuously reproducible by a playback reference model, the real-time data comprising at least one of video data and audio data,

• wherein the playback reference model includes:
• a pickup for reading the real-time data from the information recording medium;
• a buffer memory for temporarily storing the real-time data read by the pickup;
• and a decoder module for reading the real-time data from the buffer memory for processing,
• wherein the information recording medium comprises a volume space for at least recording in sectors a file comprising data and file management information for managing the file;
• the real-time data is recorded in at least two real-time extents each of which is allocated in logically contiguous sectors within the volume space;
• and
• an (i+1)th real-time extent among the at least two real-time extents is positioned at a position satisfying a real-time reproduction condition defined as:
• T(i)≦(B(i−1)+D(i))/Vout,
• wherein:
• T(i) represents a time required for the pickup to access from an end of an ith real-time extent among the at least two real-time extents to a beginning of the (i+1)th real-time extent;
• B(i) represents an amount of data having been stored in the buffer memory when the pickup accesses from the end of the ith real-time extent to the beginning of the (i+1)th real-time extent, such that B(i)=B(i−1)+D(i)−Vout×T(i), assuming that B(0)=0,
• D(i) represents an increase in the amount of data having been stored in the buffer memory responsive to the pickup reading the data from the ith real-time extent, such that D(i)=(Vin−Vout)×S(i)/Vin, wherein D(i) is corrected at least to a value equal to or smaller than M−B(i−1) when D(i)>M−B(i−1), where M represents a size of the buffer memory;
• Vout represents a data transfer rate when the data is transferred from the buffer memory to the decoder module;
• Vin represents a data transfer rate when the data is read from each of the at least two real-time extents by the pickup and transferred to the buffer memory;
• and
• S(i) represents a data size of the ith real-time extent,
• wherein the real-time file is a file in which the real-time data is appended;
• and
• wherein data of an already recorded real-time extent is recorded in a newly recorded real-time extent.

An information recording medium for recording a real-time file containing real-time data in such a manner that the real-time data is continuously reproducible by a playback reference model, the real-time data comprising at least one of video data and audio data,

• wherein the playback reference model includes:
• a pickup for reading the real-time data from the information recording medium;
• a buffer memory for temporarily storing the real-time data read by the pickup;
• and a decoder module for reading the real-time data from the buffer memory for processing,
• wherein the information recording medium comprises a volume space for at least recording in sectors a file comprising data and file management information for managing the file;
• the real-time data is recorded in at least two real-time extents each of which is allocated in logically contiguous sectors within the volume space;
• and
• an (i+1)th real-time extent among the at least two real-time extents is positioned at a position satisfying a real-time reproduction condition defined as:
• T(i)≦(B(i−1)+D(i))/Vout,
• wherein:
• T(i) represents a time required for the pickup to access from an end of an ith real-time extent among the at least two real-time extents to a beginning of the (i+1)th real-time extent;
• B(i) represents an amount of data having been stored in the buffer memory when the pickup accesses from the end of the ith real-time extent to the beginning of the (i+1)th real-time extent, such that B(i)=B(i−1)+D(i)−Vout×T(i), assuming that B(0)=0,
• D(i) represents an increase in the amount of data having been stored in the buffer memory responsive to the pickup reading the data from the ith real-time extent, such that D(i)=(Vin−Vout)×S(i)/Vin, wherein D(i) is corrected at least to a value equal to or smaller than M−B(i−1) when D(i)>M−B(i−1), where M represents a size of the buffer memory;
• Vout represents a data transfer rate when the data is transferred from the buffer memory to the decoder module;
• Vin represents a data transfer rate when the data is read from each of the at least two real-time extents by the pickup and transferred to the buffer memory;
• and
• S(i) represents a data size of the ith real-time extent,
• wherein the real-time file is a file in which the real-time data is appended;
• wherein the real-time data is compressed in an MPEG format;
• and
• wherein data comprising one or more GOPs recorded at an end of the real-time file before appending is re-encoded and is recorded in a newly recorded real-time extent.

An information recording medium comprising a volume space for at least recording in sectors a file comprising data and file management information for managing the file, wherein:

• the data comprises real-time data, the real-time data comprising at least one of video data and audio data;
• the real-time data is recorded in at least one real-time extent each of which is allocated in logically contiguous sectors within the volume space;
• the file comprises at least one real-time extent;
• a linking loss extent is positioned before each of the at least one real-time extent;
• and
• a linking gap is formed in the at least one real-time extent.

A method for recording a real-time file containing real-time data on an information recording medium in such a manner that the real-time data is continuously reproducible by a playback reference model, the real-time data comprising at least one of video data and audio data,

• wherein the playback reference model includes:
• a pickup for reading the real-time data from the information recording medium;
• a buffer memory for temporarily storing the real-time data read by the pickup;
• and a decoder module for reading the real-time data from the buffer memory for processing,
• wherein the information recording medium comprises a volume space for at least recording in sectors a file comprising data and file management information for managing the file,
• the real-time data is recorded in at least one real-time extent each of which is allocated in logically contiguous sectors within the volume space,
• wherein the method comprises the steps of:
• searching for at least two areas satisfying a real-time reproduction condition from among a plurality of logically contiguous unused areas within the volume space, each of the at least two areas being designated as a pre-allocated area, an (i+1)th pre-allocated area among the at least two areas satisfying the real-time reproduction condition being defined as:
• T(i)≦(B(i−1)+D(i))/Vout,
• wherein:
• T(i) represents a time required for the pickup to access from an end of an ith pre-allocated area among the at least two pre-allocated areas to a beginning of the (i+1)th pre-allocated area;
• B(i) represents an amount of data having been stored in the buffer memory when the pickup accesses from the end of the ith pre-allocated area to the beginning of the (i+1)th pre-allocated area, such that B(i)=B(i−1)+D(i)−Vout×T(i), assuming that B(0)=0,
• D(i) represents an increase in the amount of data having been stored in the buffer memory responsive to the pickup reading the data from the ith pre-allocated area, such that D(i)=(Vin−Vout)×S(i)/Vin, wherein D(i) is corrected at least to a value equal to or smaller than M−B(i−1) when D(i)>M−B(i−1), where M represents a size of the buffer memory;
• Vout represents a data transfer rate when the data is transferred from the buffer memory to the decoder module;
• Vin represents a data transfer rate when the data is read from the pre-allocated area by the pickup and transferred to the buffer memory;
• and
• S(i) represents a data size of the ith pre-allocated area;
• recording the real-time data in the pre-allocated area;
• designating a set of logically contiguous sectors in which real-time data is recorded as a real-time extent;
• and
• recording the file management information for managing the real-time data as the real-time file.

A method for recording a real-time file containing real-time data on an information recording medium in such a manner that the real-time data is continuously reproducible by a playback reference model, the real-time data comprising at least one of video data and audio data,

• wherein the playback reference model includes:
• a pickup for reading the real-time data from the information recording medium;
• a buffer memory for temporarily storing the real-time data read by the pickup;
• and a decoder module for reading the real-time data from the buffer memory for processing,
• wherein the information recording medium comprises a volume space for at least recording in sectors a file comprising data and file management information for managing the file,
• the real-time data is recorded in at least one real-time extent each of which is allocated in logically contiguous sectors within the volume space,
• wherein the method comprises the steps of:
• calculating whether or not each of the at least one real-time extent will cause an overflow in an amount of data stored in the buffer memory if the real-time extent is reproduced by the playback reference model;
• when it is calculated that the real-time extent will cause an overflow, correcting the amount of data stored in the buffer memory to equal to or smaller than the size of the buffer memory;
• calculating whether or not an underflow will occur in the amount of data stored in the buffer memory if the playback reference model accesses from the real-time extent to a newly-allocated pre-allocated area;
• when it is calculated that an underflow will occur, searching for a real-time extent which will not cause an underflow, on accessing from the real-time extent to the pre-allocated area;
• recording in the newly-allocated pre-allocated area the real-time data already recorded in the real-time extent which will cause an underflow;
• recording real-time data to be appended in the newly-allocated pre-allocated area;
• designating a set of logically contiguous sectors in which real-time data is recorded as a real-time extent;
• and
• recording the file management information.

A method for appending a real-time file containing real-time data on an information recording medium in such a manner that the real-time data is continuously reproducible by a playback reference model, the real-time data comprising at least one of video data and audio data,

• wherein the playback reference model includes:
• a pickup for reading the real-time data from the information recording medium;
• a buffer memory for temporarily storing the real-time data read by the pickup;
• and a decoder module for reading the real-time data from the buffer memory for processing,
• wherein the information recording medium comprises a volume space for at least recording in sectors a file comprising data and file management information for managing the file,
• the real-time data is recorded in at least one real-time extent each of which is allocated in logically contiguous sectors within the volume space,
• wherein the real-time file comprises data which is compressed in an MPEG format,
• wherein the method comprises the steps of:
• reading data recorded at an end of the real-time file before appending, the data comprising one or more GOPs;
• re-encoding the data which has been read;
• recording the re-encoded data in a newly allocated pre-allocated area;
• recording real-time data to be appended in the newly-allocated pre-allocated area;
• designating a set of logically contiguous sectors in which real-time data is recorded as a real-time extent;
• and
• recording the file management information.

A method for recording information on an information recording medium comprising a volume space for at least recording in sectors a file comprising data and file management information for managing the file, comprising the steps of:

• determining whether or not the file is a real-time file containing real-time data;
• recording the file management information in the volume space;
• recording the real-time data next to a linking loss extent if the file is determined to be a real-time file;
• and
• responsive to a buffer underrun occurring during the recording of the real-time data, forming a linking gap in a real-time extent in which the real-time data is recorded.

An information recording apparatus for recording a real-time file containing real-time data on an information recording medium in such a manner that the real-time data is continuously reproducible by a playback reference model, the real-time data comprising at least one of video data and audio data,

• wherein the playback reference model includes:
• a pickup for reading the real-time data from the information recording medium;
• a buffer memory for temporarily storing the real-time data read by the pickup;
• and a decoder module for reading the real-time data from the buffer memory for processing,
• wherein the information recording medium comprises a volume space for at least recording in sectors a file comprising data and file management information for managing the file;
• wherein the information recording apparatus comprises a file system processing section for:
• allocating at least two areas satisfying a real-time reproduction condition from among a plurality of logically contiguous unused areas within the volume space, each of the at least two areas being designated as a pre-allocated area;
• recording the real-time data and the file management information;
• designating a set of logically contiguous sectors in which real-time data is recorded as a real-time extent;
• and generating the file management information for managing the real-time data as the real-time file,
• wherein an (i+1)th pre-allocated area among the at least two pre-allocated areas is positioned at a position satisfying a real-time reproduction condition defined as:
• T(i)≦(B(i−1)+D(i))/Vout,
• wherein:
• T(i) represents a time required for the pickup to access from an end of an ith pre-allocated area among the at least two pre-allocated areas to a beginning of an (i+1)th pre-allocated area among the at least two pre-allocated areas:
• B(i) represents an amount of data having been stored in the buffer memory when the pickup accesses from the end of the ith pre-allocated area to the beginning of the (i+1)th pre-allocated area, such that B(i)=B(i−1)+D(i)−Vout×T(i), assuming that B(0)=0,
• D(i) represents an increase in the amount of data having been stored in the buffer memory responsive to the pickup reading the data from the ith pre-allocated area, such that D(i)=(Vin−Vout)×S(i)/Vin, wherein D(i) is corrected at least to a value equal to or smaller than M−B(i−1) when D(i)>M−B(i−1), where M represents a size of the buffer memory;
• Vout represents a data transfer rate when the data is transferred from the buffer memory to the decoder module;
• Vin represents a data transfer rate when the data is read from the pre-allocated area by the pickup and transferred to the buffer memory;
• and
• S(i) represents a data size of the ith pre-allocated area.

An information recording apparatus for appending a real-time file containing real-time data on an information recording medium in such a manner that the real-time data is continuously reproducible by a playback reference model, the real-time data comprising at least one of video data and audio data,

• wherein the playback reference model includes:
• a pickup for reading the real-time data from the information recording medium;
• a buffer memory for temporarily storing the real-time data read by the pickup;
• and a decoder module for reading the real-time data from the buffer memory for processing,
• wherein the information recording medium comprises a volume space for at least recording in sectors a file comprising data and file management information for managing the file,
• the real-time data is recorded in at least one real-time extent each of which is allocated in logically contiguous sectors within the volume space,
• wherein the information recording apparatus comprises:
• a data amount calculation section for calculating whether or not each of the at least one real-time extent will cause an overflow in an amount of data stored in the buffer memory if the real-time extent is reproduced by the playback reference model;
• correcting the amount of data stored in the buffer memory to equal to or smaller than the size of the buffer memory when it is calculated that the real-time extent will cause an overflow;
• calculating whether or not an underflow will occur in the amount of data stored in the buffer memory if the playback reference model accesses from the real-time extent to a newly-allocated pre-allocated area;
• and searching for a real-time extent which will not cause an underflow, on accessing from the real-time extent to the pre-allocated area when it is calculated that an underflow will occur;
• a data recording section for recording in the newly allocated pre-allocated area the real-time data already recorded in the real-time extent which will cause an underflow, and recording real-time data to be appended in the newly-allocated pre-allocated area;
• and
• a file structure processing section for designating a set of logically contiguous sectors in which real-time data is recorded as a real-time extent and for generating and recording the file management information.

An information recording apparatus for appending a real-time file containing real-time data on an information recording medium in such a manner that the real-time data is continuously reproducible by a playback reference model, the real-time data comprising at least one of video data and audio data,

• wherein the playback reference model includes:
• a pickup for reading the real-time data from the information recording medium;
• a buffer memory for temporarily storing the real-time data read by the pickup;
• and a decoder module for reading the real-time data from the buffer memory for processing,
• wherein the information recording medium comprises a volume space for at least recording in sectors a file comprising data and file management information for managing the file,
• the real-time data is recorded in at least one real-time extent each of which is allocated in logically contiguous sectors within the volume space,
• wherein the real-time file comprises data which is compressed in an MPEG format,
• wherein the information recording apparatus comprises:
• a re-encoding section for reading data recorded at an end of the real-time file before appending, the data comprising one or more GOPs, re-encoding the data which has been read, and recording the re-encoded data in a newly allocated pre-allocated area;
• and
• a file structure processing section for designating a set of logically contiguous sectors in which real-time data is recorded as a real-time extent and for generating and recording the file management information.

An information recording apparatus for recording information on an information recording medium comprising a volume space for at least recording in sectors a file comprising data and file management information for managing the file, comprising:

• a recording mode determination section for determining whether or not the file is a real-time file containing real-time data;
• a file structure processing section for recording the file management information in the volume space;
• a linking setting section for recording the real-time data next to a linking loss extent if the file is determined to be a real-time file;
• and
• a linking controller for, responsive to a buffer underrun occurring during the recording of the real-time data, forming a linking gap in a real-time extent in which the real-time data is recorded.

A system controller for an information recording apparatus for recording a real-time file containing real-time data on an information recording medium in such a manner that the real-time data is continuously reproducible by a playback reference model, the real-time data comprising at least one of video data and audio data,

• wherein the playback reference model includes:
• a pickup for reading the real-time data from the information recording medium;
• a buffer memory for temporarily storing the real-time data read by the pickup;
• and a decoder module for reading the real-time data from the buffer memory for processing,
• wherein the information recording medium comprises a volume space for at least recording in sectors a file comprising data and file management information for managing the file;
• wherein the system controller comprises a file system processing section for:
• allocating at least two areas satisfying a real-time reproduction condition from among a plurality of logically contiguous unused areas within the volume space, each of the at least two areas being designated as a pre-allocated area;
• recording the real-time data and the file management information;
• designating a set of logically contiguous sectors in which real-time data is recorded as a real-time extent;
• and generating the file management information for managing the real-time data as the real-time file,
• wherein an (i+1)th pre-allocated area among the at least two pre-allocated areas is positioned at a position satisfying a real-time reproduction condition defined as:
• T(i)≦(B(i−1)+D(i))/Vout,
• wherein:
• T(i) represents a time required for the pickup to access from an end of an ith pre-allocated area among the at least two pre-allocated areas to a beginning of an (i+1)th pre-allocated area among the at least two pre-allocated areas;
• B(i) represents an amount of data having been stored in the buffer memory when the pickup accesses from the end of the ith pre-allocated area to the beginning of the (i+1)th pre-allocated area, such that B(i)=B(i−1)+D(i)/Vout×T(i), assuming that B(0)=0,
• D(i) represents an increase in the amount of data having been stored in the buffer memory responsive to the pickup reading the data from the ith pre-allocated area, such that D(i)=(Vin−Vout)×S(i)/Vin, wherein D(i) is corrected at least to a value equal to or smaller than M−B(i−1) when D(i)>M−B(i−1), where M represents a size of the buffer memory;
• Vout represents a data transfer rate when the data is transferred from the buffer memory to the decoder module;
• Vin represents a data transfer rate when the data is read from the at pre-allocated are by the pickup and transferred to the buffer memory;
• and
• S(i) represents a data size of the ith pre-allocated area.

A system controller for an information recording apparatus for appending a real-time file containing real-time data on an information recording medium in such a manner that the real-time data is continuously reproducible by a playback reference model, the real-time data comprising at least one of video data and audio data,

• wherein the playback reference model includes:
• a pickup for reading the real-time data from the information recording medium;
• a buffer memory for temporarily storing the real-time data read by the pickup;
• and a decoder module for reading the real-time data from the buffer memory for processing,
• wherein the information recording medium comprises a volume space for at least recording in sectors a file comprising data and file management information for managing the file,
• the real-time data is recorded in at least one real-time extent each of which is allocated in logically contiguous sectors within the volume space,
• wherein the system controller comprises:
• a data amount calculation section for calculating whether or not each of the at least one real-time extent will cause an overflow in an amount of data stored in the buffer memory if the real-time extent is reproduced by the playback reference model;
• correcting the amount of data stored in the buffer memory to equal to or smaller than the size of the buffer memory when it is calculated that the real-time extent will cause an overflow;
• calculating whether or not an underflow will occur in the amount of data stored in the buffer memory if the playback reference model accesses from the real-time extent to a newly-allocated pre-allocated area;
• and searching for a real-time extent which will not cause an underflow, on accessing from the real-time extent to the pre-allocated area when it is calculated that an underflow will occur;
• a data recording section for recording in the newly allocated pre-allocated area the real-time data already recorded in the real-time extent which will cause an underflow, and recording real-time data to be appended in the newly-allocated pre-allocated area;
• and
• a file structure processing section for designating a set of logically contiguous sectors in which real-time data is recorded as a real-time extent and for generating and recording the file management information.

A method for reproducing a real-time file containing real-time data on an information recording medium in such a manner that the real-time data is continuously reproducible by a playback reference model, the real-time data comprising at least one of video data and audio data,

• wherein the playback reference model includes:
• a pickup for reading the real-time data from the information recording medium;
• a buffer memory for temporarily storing the real-time data read by the pickup;
• and a decoder module for reading the real-time data from the buffer memory for processing,
• wherein the information recording medium comprises a volume space for at least recording in sectors a file comprising data and file management information for managing the file,
• wherein the real-time data is recorded in at least two real-time extents each of which is allocated in logically contiguous sectors within the volume space;
• and
• an (i+1)th real-time extent among the at least two real-time extents is positioned at a position satisfying a real-time reproduction condition defined as:
• T(i)≦(B(i1l)+D(i))/Vout,
• wherein:
• T(i) represents a time required for the pickup to access from an end of an ith real-time extent among the at least two real-time extents to a beginning of the (i+1)th real-time extent;
• B(i) represents an amount of data having been stored in the buffer memory when the pickup accesses from the end of the ith real-time extent to the beginning of the (i+1)th real-time extent, such that B(i)=B(i−1)+D(i)−Vout×T(i), assuming that B(0)=0,
• D(i) represents an increase in the amount of data having been stored in the buffer memory responsive to the pickup reading the data from the ith real-time extent, such that D(i)=(Vin−Vout)×S(i)/Vin, wherein D(i) is corrected at least to a value equal to or smaller than M−B(i−1) when D(i)>M−B(i−1), where M represents a size of the buffer memory;
• Vout represents a data transfer rate when the data is transferred from the buffer memory to the decoder module;
• Vin represents a data transfer rate when the data is read from each of the at least two real-time extents by the pickup and transferred to the buffer memory;
• and
• S(i) represents a data size of the ith real-time extent,
• wherein the method comprises the steps of:
• reproducing the real-time file from the information recording medium by means of a disk drive;
• acquiring location information of each of the at least two real-time extents and identification information indicating that the at least two real-time extents are positioned in accordance with the real-time reproduction condition;
• reading data from the at least two real-time extents at a data transfer rate which is equal to or greater than Vin of the playback reference model;
• temporarily storing the real-time data which has been read in the buffer memory;
• reading the data stored in the buffer memory and decoding the data in a decoder;
• and
• accessing a next real-time extent within the time T(i) of the playback reference model.

A method for reproducing real-time data from an information recording medium comprising a volume space for at least recording in sectors a file comprising data and file management information for managing the file, wherein:

• the data comprises real-time data, the real-time data comprising at least one of video data and audio data;
• the real-time data is recorded in at least one real-time extent each of which is allocated in logically contiguous sectors within the volume space;
• the file comprises at least one real-time extent;
• a linking loss extent is positioned before each of the at least one real-time extent;
• and
• a linking gap is formed in the at least one real-time extent,
• wherein the method comprises the steps of:
• determining whether or not the file is a real-time file containing real-time data;
• and
• performing a reproduction operation for data recorded in a real-time extent, the reproduction operation being continuously performed without performing a recovery process even if a reproduction error due to invalid data recorded in the linking gap occurs.

An information reproduction apparatus for reproducing a real-time file containing real-time data on an information recording medium in such a manner that the real-time data is continuously reproducible by a playback reference model, the real-time data comprising at least one of video data and audio data,

• wherein the playback reference model includes:
• a pickup for reading the real-time data from the information recording medium;
• a buffer memory for temporarily storing the real-time data read by the pickup;
• and a decoder module for reading the real-time data from the buffer memory for processing,
• wherein the information recording medium comprises a volume space for at least recording in sectors a file comprising data and file management information for managing the file,
• wherein the real-time data is recorded in at least two real-time extents each of which is allocated in logically contiguous sectors within the volume space;
• and
• an (i+1)th real-time extent among the at least two real-time extents is positioned at a position satisfying a real-time reproduction condition defined as:
• T(i)≦(B(i−1)+D(i))/Vout,
• wherein:
• T(i) represents a time required for the pickup to access from an end of an ith real-time extent among the at least two real-time extents to a beginning of the (i+1)th real-time extent;
• B(i) represents an amount of data having been stored in the buffer memory when the pickup accesses from the end of the ith real-time extent to the beginning of the (i+1)th real-time extent, such that B(i)=B(i−1)+D(i)−Vout×T(i), assuming that B(0)=0,
• D(i) represents an increase in the amount of data having been stored in the buffer memory responsive to the pickup reading the data from the ith real-time extent, such that D(i)=(Vin−Vout)×S(i)/Vin, wherein D(i) is corrected at least to a value equal to or smaller than M−B(i−1) when D(i)>M−B(i−1), where M represents a size of the buffer memory;
• Vout represents a data transfer rate when the data is transferred from the buffer memory to the decoder module;
• Vin represents a data transfer rate when the data is read from each of the at least two real-time extents by the pickup and transferred to the buffer memory;
• and
• S(i) represents a data size of the ith real-time extent,
• wherein the information reproduction apparatus comprises:
• a disk drive for reproducing the real-time file from the information recording medium;
• a file structure processing section for acquiring location information of each of the at least two real-time extents and identification information indicating that the at least two real-time extents are positioned in accordance with the real-time reproduction condition;
• a data reproducer for reading data from the at least two real-time extents at a data transfer rate which is equal to or greater than Vin of the playback reference model;
• a buffer memory for temporarily storing the real-time data which has been read;
• and
• a decoder for reading the data stored in the buffer memory and decoding the data,
• wherein a data reproduction performance which is determined as a function of an access performance and data transfer rate of the data reproducer and a size of the buffer memory satisfies a predetermined data reproduction performance of the playback reference model.

An information reproduction apparatus for reproducing a real-time file containing real-time data on an information recording medium comprising a volume space for at least recording in sectors a file comprising data and file management information for managing the file,

• wherein:
• the data comprises real-time data, the real-time data comprising at least one of video data and audio data;
• the real-time data is recorded in at least one real-time extent each of which is allocated in logically contiguous sectors within the volume space;
• the file comprises at least one real-time extent;
• a linking loss extent is positioned before each of the at least one real-time extent;
• and
• a linking gap is formed in the at least one real-time extent,
• wherein the information reproduction apparatus comprises:
• a file structure processing section for determining whether or not the file is a real-time file containing real-time data;
• and
• a data reproducer for performing a reproduction operation for data recorded in a real-time extent, the reproduction operation being continuously performed without performing a recovery process even if a reproduction error due to invalid data recorded in the linking gap occurs.