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Description  |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a data recording medium, a data
recording/reproducing apparatus and a data recording/reproducing method
for recording/reproducing variable-bitrate-compressed video data and audio
data synchronized with the video data in each unit of a fixed length. More
particularly, the present invention relates to a data
recording/reproducing apparatus and a data recording/reproducing method
that rapidly performs a recording/reproducing operation of video data, in
particular, a trickplay mode operation such as fast forward reproducing
and rewind reproducing by using the data recording medium and also
performs a postrecording operation to rewrite the audio data alone.
2. Description of the Related Art
Recently, image coding techniques for variable-bitrate-compression of video
data in units of a picture have been studied in order to attain fast
transfer of mass digital video data and recording of the mass digital
video data in a data recording medium having a limited capacity. The MPEG
standard, which is one of the image coding techniques, prescribes a
compression method for digital video data by combining an I picture that
is intra-picture (intra-frame or intra-field) compression coded and a P
picture or a B picture that is inter-picture (inter-frame or inter-field)
compression encoded. Such a data compression technique realizes the
compression of digital video data from, for example, 150 Mbps into 3 Mbps.
In this method, however, the compression ratio of the digital video data
depends upon the contents of the video data and the image correlations
within the previous and subsequent pictures, and hence, each picture has a
largely different capacity. For example, when the average data rate of the
compressed video data is 3 Mbps, an image with little motion is compressed
into 1 Mbps, while an image with much motion can be compressed into only
10 Mbps. Further, an I picture, a P picture and a B picture forming a
series of scenes have respectively different capacities: on the average it
is regarded that the I picture has a capacity approximately twice as large
as that of the P picture and approximately four times as large as that of
the B picture on the average. Therefore, when video data that is
variable-bitrate-compressed in units of a picture is recorded on
continuous areas on a medium such as an optical disk, where sectors each
having a fixed length of, for example, 2 KB (2048 bytes) are previously
formed, the location for each picture is largely varied. When such a data
recording medium storing the compressed video data is used to perform a
trickplay mode operation (such as the fast forward reproducing and the
rewind reproducing) using the I picture data alone, it is indispensable to
efficiently manage the location data on the I picture data which is
located on the recording medium at unequal intervals.
In the MPEG standard, data is compressed in units of a GOP (group of
pictures) including one I picture and a plurality of P pictures and B
pictures. For example, when an NTSC signal for displaying approximately 30
pictures per 1 second is compressed into units of a GOP including twelve
pictures, video data per 1 second includes 2.5 I picture data. Therefore,
when a movie title of 135 minutes-is compressed under this condition, the
title includes as many as 20,250 I picture data. For recording all
location data of such a large amount of I picture data using an address of
four byte length in one continuous area of a medium, the size of this area
is approximately 80 KB. Considering that the buffer capacity for an audio
decoder forming a target decoder system described in the MPEG standard is
limited within only 4 KB, the 80 KB capacity of a buffer for storing the
location data of all I picture data makes it significantly difficult to
realize a compact system.
Further, when variable-bitrate-compressed video data and audio data
synchronized with the video data are interleaved in units of a sector to
be recorded on a recording medium, the audio data is located on the
recording medium at unequal intervals even if the audio data is a fixed
length data obtained by non-compression coding or
constant-bitrate-compression coding. Accordingly, when a rewritable data
recording medium where such video data and the audio data are previously
recorded is used to rewrite the audio data alone, i.e., to perform a
postrecording operation, it is indispensable to efficiently manage the
location data of the audio data which is located on the medium at unequal
intervals.
For example, when stereo audio data is compressed in accordance with the
MPEG standard into the data rate of 224 Kbps, i.e., 28 KB/s, a movie title
of 135 minutes includes 226,800 KB of compressed audio data. When the
compressed audio data is interleaved with the video data in units of a 2
KB sector to be recorded on a data recording medium, the compressed audio
data is dispersedly recorded in 113,400 sectors. For recording all
location data of such a large amount of audio data using an address of
four byte length in one continuous area of a medium, the size of this area
is approximately 450 KB. Further, when the entire audio data in a GOP is
recorded in one continuous area, the number of the audio data is identical
to that of the I picture data. Therefore, for recording all location data
of these audio data in one continuous area, the Size of this area is
approximately 80 KB. The 450 KB or 80 KB capacity of a buffer is too large
as compared with the limitation of buffer capacity for an audio decoder as
described above, resulting in restricting the design of compact systems.
SUMMARY OF THE INVENTION
The data recording medium of this invention is a medium having a plurality
of units with a fixed length, and is used for recording AV files each
including the video data that is compressed in units of a picture on the
variable-bitrate condition. Each of the AV files recorded on the data
recording medium includes a plurality of chapter data including a
plurality of GOP data, a plurality of first pointer data each having a
plurality of first pointers, and at least one second pointer data having a
plurality of second pointers; each of the GOP data includes one
independent picture data that is intra-picture compressed and a plurality
of dependent picture data that are inter-picture compressed; each of the
first pointers is provided in a one-to-one correspondence to each of the
independent picture data, and stores location data of the corresponding
independent picture data; each of the second pointers is provided in a
one-to-one correspondence to each of the first pointer data and stores
location data of the corresponding first pointer data; and a hierarchical
location data for retrieving the independent picture data is formed by the
first pointers and the second pointers.
In one embodiment of the data recording medium of this invention, each of
the chapter data is arranged adjacent to one of the first pointer data
which includes the first pointers corresponding to the independent picture
data included in that particular chapter data.
In one embodiment of the data recording medium of this invention, the
chapter data and the first pointer data are alternately located, and each
of the first pointer data includes the first pointers corresponding to the
independent picture data included in the chapter data adjacent to that
particular first pointer data.
In one embodiment of the data recording medium of this invention, the
second pointer data is located at the top and/or end portions of each of
the AV files, and the second pointer data includes all of the second
pointers corresponding to the first pointer data included in the
corresponding AV file, thereby storing the location data on all of the
first pointer data included in the corresponding AV file.
In one embodiment of the data recording medium of this invention, each of
the GOP data further includes audio data.
In one embodiment of the data recording medium of this invention, the audio
data is interleaved with the independent picture data and the dependent
picture data of the basis of each unit with the fixed length, and a data
type code for discriminating the independent picture data is recorded in
each unit with the fixed length.
In one embodiment of the data recording medium of this invention, a padding
data is added to the independent picture data, thereby the independent
picture data to which the padding data is added completing each unit with
the fixed length, and a valid data length for discriminating the padding
data is recorded in each unit with the fixed length.
The data reproducing apparatus of this invention uses a data recording
medium having a plurality of units with a fixed length, in order to record
AV files each including the video data that is compressed in units of a
picture on the variable-bitrate condition. Each of the AV files including
a plurality of chapter data including a plurality of GOP data, a plurality
of first pointer data each having a plurality of first pointers, and a
plurality of second pointer data each having a plurality of second
pointers; each of the GOP data including one independent picture data that
is intra-picture compressed and a plurality of dependent picture data that
are inter-picture compressed; each of the first pointers being provided in
a one-to-one correspondence to each of the independent picture data and
storing location data of the corresponding independent picture data; each
of the second pointers being provided in a one-to-one correspondence to
each of the first pointer data and storing location data of the
corresponding first pointer data. The data reproducing apparatus
comprises: a pointer reproducing means for reading out the first and the
second pointer data from the data recording medium; a first pointer data
storing circuit for temporarily storing the read first pointer data; a
second pointer data storing circuit for temporarily storing the read
second pointer data; a control circuit for retrieving the location data of
the first pointer data based on the second pointer data stored in the
second pointer data storing circuit, and retrieving the location data of
the independent picture data based on the retrieved location data of the
first pointer data and the first pointer data stored in the first pointer
data storing circuit; and a picture reproducing means for reproducing a
predetermined piece of the independent picture data from the data
recording medium based on the retrieved location data of the independent
picture data.
In one embodiment of the data reproducing apparatus of this invention, the
control circuit comprises a circuit for selecting the location data of the
independent picture data to be retrieved in accordance with an externally
determined reproducing speed.
In one embodiment, the data reproducing apparatus of this invention uses
the data recording medium in which each of the GOP data further includes
audio data being interleaved with the independent picture data and the
dependent picture data of the basis of each unit with the fixed length, a
data type code for discriminating the independent picture data being
recorded on the basis of each unit with the fixed length, and the data
reproducing apparatus further comprises a data type discriminating circuit
for discriminating the data type code recorded in the unit with the fixed
length.
In one embodiment, the data reproducing apparatus of this invention uses
the data recording medium in which a padding data is added to the
independent picture data so that the independent picture data to which the
padding data is added completes each unit with the fixed length, a valid
data length for discriminating the padding data being recorded on the
basis of each unit with the fixed length, and the data reproducing
apparatus further comprises a data length detection circuit for detecting
the valid data length recorded in the unit with the fixed length.
The data reproducing method of this invention uses a data recording medium
having a plurality of units with a fixed length, in order to reproduce AV
files each including the video data that is compressed in units of a
picture on the variable-bitrate condition, each of the AV files including
a plurality of chapter data including a plurality of GOP data, a plurality
of first pointer data each having a plurality of first pointers, and at
least one second pointer data each having a plurality of second pointers;
each of the GOP data including one independent picture data that is
intra-picture compressed and a plurality of dependent picture data that
are inter-picture compressed; each of the first pointers being provided in
a one-to-one correspondence to each of the independent picture data and
storing location data of the corresponding independent picture data; each
of the second pointers being provided in a one-to-one correspondence to
each of the first pointer data and storing location data of the
corresponding first pointer data, thereby selectively reproducing the
independent picture data. The method comprises the steps of: receiving an
externally supplied reproducing condition; reading out the second pointer
data from the data recording medium; temporarily storing the read second
pointer data; searching the stored second pointer data to retrieve the
location data of the first pointer data satisfying the reproducing
condition; reading out the first pointer data from the data recording
medium based on the retrieved location data of the first pointer data;
searching the stored first pointer data to retrieve the location data of
the independent picture data satisfying the reproducing condition; and
reproducing the independent picture data from the data recording medium
based on the retrieved location data of the independent picture data.
In one embodiment of the data reproducing method of this invention, the
reproducing condition includes a reproducing speed, and in the step of
retrieving the location data of the independent picture data, the location
data of the independent picture data to be retrieved is selected in
accordance with the reproducing speed, thereby adjusting the interval
between the independent picture data that is to be reproduced.
In one embodiment, the data reproducing method uses data recording medium
in which each of the GOP data further includes an audio data being
interleaved with the independent picture data and the dependent picture
data on the basis of each unit with the fixed length, a data type code for
discriminating the independent picture data being recorded on the basis of
each unit with the fixed length. The step of retrieving the location data
of the independent picture data includes the step of discriminating the
data type code recorded in the unit with the fixed length, thereby
selectively reproducing the independent picture data alone.
In one embodiment, the data reproducing method uses the data recording
medium in which a padding data is added to the independent picture data so
that the independent picture data to which the padding data is added
completes each unit with the fixed length, a valid data length for
discriminating the padding data being recorded on the basis of each unit
with the fixed length. The step of retrieving the location data of the
independent picture data includes the step of detecting the valid data
length recorded in the unit with the fixed length, thereby reproducing the
independent picture data excluding the padding data.
In one embodiment, the data reproducing method uses the data recording
medium in which the second pointer data is located at top and end portions
of each of the AV files, the second pointer data including all the second
pointers corresponding to the first pointer data included in the
corresponding AV file. The step of reading out the second pointer data
comprises the steps of: reading the second pointer data recorded at the
top portion of the AV file, and when the second pointer data recorded at
the top portion of the AV file is unreadable, reading the second pointer
data recorded at the end portion of the AV file; and reading the second
pointer data at the end portion of the AV file, and when the second
pointer data recorded at the end portion of the AV file is unreadable,
reading the second pointer data recorded at the top portion of the AV
file.
In one embodiment, the data reproducing method uses the data recording
medium in which the chapter data and the first pointer data are
alternately located, and each of the first pointer data includes the first
pointers corresponding to the independent picture data included in the
chapter data adjacent to that particular first pointer data, the first
pointers include both prepointers storing the location data of the
independent picture data included in one of the chapter data located
immediately before the corresponding first pointer data and postpointers
storing the location data of the independent picture data included in one
of the chapter data located immediately after the corresponding first
pointer data. The step of reading out the first pointer data comprises the
steps of: reading the postpointers included in the nth first pointer data,
and when the postpointers included in the nth first pointer data are
unreadable, reading the prepointers included in the (n+1)th first pointer
data; and reading the prepointers included in the nth first pointer data,
and when the prepointers included in the nth first pointer data are
unreadable, reading the postpointers included in the (n-1)th first pointer
data.
The data recording medium of this invention is a medium having a plurality
of units with a fixed length, and is used for recording AV files each
including the video data that is compressed in units of a picture on the
variable-bitrate condition. Each of the AV files recorded on the data
recording medium includes a plurality of chapter data including a
plurality of GOP data, a plurality of first pointer data each having a
plurality of first pointers, and at least one second pointer data having a
plurality of second pointers; each of the GOP data includes at least one
picture data and at least one audio data; each of the first pointers is
provided in a one-to-one correspondence to each of the audio data and
stores location data of the corresponding audio data; each of the second
pointers is provided in a one-to-one correspondence to each of the first
pointer data and stores location data of the corresponding first pointer
data; and a hierarchical location data for retrieving the audio data is
formed by the first pointers and the second pointers.
In one embodiment of the data recording medium according to this invention,
each of the chapter data is arranged adjacent to one of the first pointer
data including the first pointers corresponding to the audio data included
in that particular chapter data.
In one embodiment of the data recording medium according to this invention,
the chapter data and the first pointer data are alternately located, and
each of the first pointer data includes the first pointers corresponding
to the audio data included in the chapter data adjacent to that particular
first pointer data.
In one embodiment of the data recording medium according to this invention,
the second pointer data is located at the top portion and/or end portion
of each of the AV files, and the second pointer data includes all of the
second pointers corresponding to the first pointer data included in the
corresponding AV file, thereby storing the location data on all of the
first pointer data included in the corresponding AV file.
The data recording/reproducing apparatus of this invention uses a recording
medium for recording and reproducing each unit with a fixed length of a
data. The apparatus comprises: a video data generating circuit for
generating a compressed picture data by variable-bitrate-compressing an
externally input video signal in units of a picture; an audio data
generating circuit for generating audio data from externally input audio
signal; an interleaving circuit for generating GOP data by interleaving
the compressed picture data and the audio data on the basis of each unit
with the fixed length, the interleaving being performed in units of a
picture group (GOP) including a predetermined number of pictures, and
generating a chapter data including a plurality of the GOP data; a means
for generating a plurality of first pointers, each first pointer being
provided in a one-to-one correspondence to each of the audio data included
in the chapter data so as to store a location data of the corresponding
audio data, and for generating a first pointer data by allocating the
plurality of the first pointers in a predetermined order; a first pointer
data storing circuit for temporarily storing the first pointer data; a
means for generating a plurality of second pointers, each second pointer
being provided in a one-to-one correspondence to each of the first pointer
data so as to store a location data of the corresponding first pointer
data, and for generating a second pointer data by allocating the plurality
of the second pointers in a predetermined order; a second pointer data
storing circuit for temporarily storing the second pointers; a means for
generating an AV file by alternately allocating the first pointer data and
the chapter data and positioning the second pointer data at a
predetermined location; and a circuit for recording the AV file on the
data recording medium.
In one embodiment, the data recording/reproducing apparatus uses the
recording medium in which the second pointer data includes all the second
pointers corresponding to the first pointer data included in the
corresponding AV file, and the means for generating the AV file allocating
the second pointer data at top and/or end portions of each of the AV
files.
The data recording/reproducing apparatus of this invention uses an data
recording medium having a plurality of units with a fixed length, in order
to record AV files each including the video data that is compressed in
units of a picture on the variable-bitrate condition, each of the AV files
including a plurality of chapter data including a plurality of GOP data, a
plurality of first pointer data each having a plurality of first pointers,
and at least one second pointer data each having a plurality of second
pointers; each of the GOP data including at least one picture data and at
least one audio data; each of the first pointers being provided in a
one-to-one correspondence to each of the audio data and storing location
data of the corresponding audio data; each of the second pointers being
provided in a one-to-one correspondence to each of the first pointer data
and storing location data of the corresponding first pointer data. The
apparatus comprises a postrecording control means including: a means for
reading the first and the second pointer data from the data recording
medium; a means for detecting a location of the audio data by using the
read first and second pointer data; and a circuit for recording input
audio data at the detected location.
In one embodiment of the data recording/reproducing apparatus of the
present invention, the video data generating circuit and the audio data
generating circuit add a data type code for discriminating the kind of
data to be recorded to each unit with the fixed length.
In one embodiment of the data recording/reproducing apparatus of the
present invention, the video data generating circuit and the audio data
generating circuit add a padding data to each of the compressed picture
data and the audio data, and add a valid data length for discriminating
the padding data to each unit with the fixed length in the compressed
picture data and the audio data.
The data recording/reproducing method according to this invention uses a
data recording medium for recording/reproducing each unit with a fixed
length of data. The method comprises the steps of: generating a compressed
picture data by variable-bitrate-compressing an externally input video
signal in units of a picture; generating audio data from externally input
audio signal; generating GOP data by interleaving the compressed picture
data and the audio data on the basis of each unit with the fixed length,
the interleaving being performed in units of a picture group (GOP)
including a predetermined number of pictures; generating a chapter data
including a plurality of the GOP data; generating a plurality of first
pointers, each first pointer being provided in a one-to-one correspondence
to each of the audio data included in the chapter data so as to store
location data of the corresponding audio data and, generating a first
pointer data by allocating the plurality of the first pointers in a
predetermined order; temporarily storing the first pointer data;
generating a plurality of second pointers, each second pointer being
provided in a one-to-one correspondence to each of the first pointer data
so as to store location data of the corresponding first pointer data, and
generating a second pointer data by allocating the plurality of the second
pointers in a predetermined order; temporarily storing the second
pointers; generating an AV file by alternately allocating the first
pointer data and the chapter data and positioning the second pointer data
at a predetermined location; and recording the AV file on the data
recording medium.
The data recording/reproducing method according to this invention uses a
data recording medium having a plurality of units with a fixed length, in
order to record/reproduce AV files each including the video data that is
compressed in units of a picture on the variable-bitrate condition, each
of the AV files including a plurality of chapter data including a
plurality of GOP data, a plurality of first pointer data each having a
plurality of first pointers, and at least one second pointer data each
having a plurality of second pointers; each of the GOP data including at
least one picture data and at least one audio data; each of the first
pointers being provided in a one-to-one correspondence to each of the
audio data and storing location data of the corresponding audio data; each
of the second pointers being provided in a one-to-one correspondence to
each of the first pointer data and storing location data on the
corresponding first pointer data. The method comprises a postrecording
control step including the steps of: reading the first and the second
pointer data from the data recording medium; detecting location of the
audio data by using the read first and second pointer data; and recording
an input audio data at the detected location.
In one embodiment, the data recording/reproducing method uses the recording
medium in which the second pointer data includes all the second pointers
corresponding to the first pointer data included in the corresponding AV
file, in the step of recording the AV file, the second pointer data is
allocated at the top and end portions of each AV file. The step of reading
the second pointer data included in the postrecording control step further
includes the step of reading the second pointer data recorded at the end
portion of the AV file when the second pointer data recorded at the top
portion of the AV file is unreadable.
In one embodiment, the data recording/reproducing method uses the recording
medium in which the audio pointers in the first pointer data include both
prepointers storing the location data of the audio data included in one of
the chapter data located immediately before the corresponding first
pointer data and postpointers storing the location data of the audio data
included in one of the chapter data located immediately after the
corresponding first pointer data. The step of reading the first pointer
data included in the postrecording control step comprises the step of:
reading the postpointers included in the nth first pointer data, and when
the postpointers included in the nth first pointer data are unreadable,
reading the prepointers included in the (n+1)th first pointer data.
Thus, the invention described herein makes possible the advantages of (1)
providing a data recording medium having a data structure capable of
efficiently managing the location data on a plurality of I picture data
located on the recording medium at unequal intervals; (2) providing a data
reproducing apparatus and a data reproducing method for performing a
trickplay mode operation such as fast forward reproducing and rewind
reproducing by using the data recording medium; (3) providing a data
recording medium having a data structure capable of efficiently managing
the location data of a plurality of audio data recorded on the data
recording medium at unequal intervals by interleaving with
variable-bitrate-compressed video data in units of a sector; and (4)
providing a data reproducing apparatus and a data reproducing method for
conducting a postrecording operation by using the data recording medium.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the area structure of a data recording medium according to one
example of the present invention;
FIG. 2 shows the data structure of an AV file and the hierarchical
structure of global pointer data and picture pointer data formed on the
data recording medium of FIG. 1;
FIGS. 3A and 3B show examples of the data structure of a GOP data;
FIG. 4 shows the data structure in a physical sector;
FIG. 5 is a block diagram of the configuration of a data reproducing
apparatus according to one example of this invention;
FIG. 6 is a block diagram of the configuration of a sub-code discriminating
circuit;
FIG. 7 is a flowchart for the processing procedures for a fast forward
reproducing operation by using the data reproducing apparatus of the
present invention;
FIG. 8 is a flowchart for the processing procedures for a rewind
reproducing operation by using the data reproducing apparatus of the
present invention;
FIG. 9 is a block diagram of the configuration of a data
recording/reproducing apparatus according to one example of the present
invention;
FIG. 10 is a block diagram of the configuration of an interleaving circuit;
FIG. 11 is a flowchart for the processing procedures for an ordinary
recording operation by using the data recording/reproducing apparatus of
the present invention;
FIG. 12 shows the data structure of an AV file formed on a rewritable data
recording medium; and
FIG. 13 is a flowchart for the processing procedures for a postrecording
operation by using the data recording/reproducing apparatus of the present
invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
According to the present invention, a data (information) recording medium
storing AV files each including a video data that is
variable-bitrate-compressed in units of a picture, is used to conduct fast
forward reproducing and rewind reproducing at a high speed. In each of the
AV files recorded on the data recording medium of the present invention,
an independent picture data is hierarchically managed by a first pointer
data (picture pointer data) having the location data of the independent
picture data included in each chapter data and a second pointer data
(global pointer data) having the location data of the first pointer data.
In a data reproducing apparatus and a data reproducing method of the
present invention, the location data of the independent picture data is
managed by using a hierarchical data structure, and the location data for
a large number of the independent picture data located in the AV files at
unequal intervals is efficiently retrieved without using a bulk memory,
thereby conducting the fast forward reproducing and the rewind reproducing
at a high speed.
Further, in the present invention, a data recording medium for storing AV
files where audio data and variable-bitrate-compressed video data are
interleaved is used to conduct a postrecording operation. In each of the
AV files recorded on the data recording medium, the audio data is
hierarchically managed by a first pointer data (audio pointer data) having
the location data of the audio data included in each chapter data and a
second pointer data (global pointer data). In the data
recording/reproducing apparatus and recording/reproducing method of the
present invention, the location data of the audio data is managed by using
such a hierarchical data structure, and the location data for a large
number of the audio data located in the AV files at unequal intervals is
efficiently managed without using bulk memory, thereby realizing a
postrecording operation in which the audio data alone is rewritten.
The data recording medium of the present invention, and the data
recording/reproducing apparatus and the data recording/reproducing method
using the data recording medium will now be described referring to the
accompanying drawings. The data recording/reproducing apparatus of the
present invention is capable of a rapid trickplay mode operation such as
fast forward reproducing and rewind reproducing of video data as well as
ordinary recording/reproducing operations, and can perform a postrecording
operation in which audio data alone is rewritten.
EXAMPLE 1
FIG. 1 shows the area structure of a data recording medium 200 according to
Example 1 of the present invention. The data recording medium 200 has a
data structure for rapidly conducting a trickplay mode operation. On the
disk-shaped data recording medium 200 are formed a large number of
concentrical or spiral tracks. Each track is divided into a large number
of sectors 201 each including a header field for storing an address data
and the like and a data field for storing user data of, for example, 2048
bytes. In a read-only recording medium, both the header field and the data
field are pre-formatted during the production process of the medium. In a
rewritable recording medium, the header field alone is preliminarily
formulated during the production.
In the data recording medium 200, a file recording area 202 is assigned to
the outer tracks, and a file management area 203 is assigned to the inner
tracks. The file recording area 202 stores a large number of AV files 210
each including a variable-bitrate-compressed video data. The file
management area 203 stores file control data 220 for each AV file 210, in
which a volume name and the number of the stored AV files are recorded at
the leading portion followed by a large number of file entries 221 each
corresponding to each of the AV files 210. Each of the file entries 221
includes a file related data such as the file name, the file location and
the file size of the corresponding AV file.
FIG. 2 shows the data structure of the AV file 210 shown in FIG. 1. As is
shown in FIG. 2, picture pointer data 230 and chapter data 240 are
alternately located in the AV file 210, wherein the first and second
global pointer data 250 are located at the top and end portions,
respectively. The global pointer data 250, the pict | | |
