U.S. patent application number 09/190945 was filed with the patent office on 2002-04-25 for data recording and reproducing apparatus and method for recording and reproducing data from a non-linear recording medium.
Invention is credited to FUJITA, HIROYUKI, ITO, NORIKAZU, KATSUO, SATOSHI, SATO, KOICHI, SHIGA, TOMOHISA, YONEYA, SATOSHI, YOSHIKAWA, JUN, YOSHIMOTO, MASAKAZU, YUTANI, SATOSHI.
Application Number | 20020049696 09/190945 |
Document ID | / |
Family ID | 18067894 |
Filed Date | 2002-04-25 |
United States Patent
Application |
20020049696 |
Kind Code |
A1 |
FUJITA, HIROYUKI ; et
al. |
April 25, 2002 |
DATA RECORDING AND REPRODUCING APPARATUS AND METHOD FOR RECORDING
AND REPRODUCING DATA FROM A NON-LINEAR RECORDING MEDIUM
Abstract
In a data recording and reproducing apparatus (10), according to
a release instruction from a server controller (30) added to a
PLAY_OPEN command for requesting preparation of reproduction of
arbitrary data, management information is changed so that an area
occupied by reproduced data of the data in the on-producing file
becomes an area where new data can be recorded anytime while the
file is reproduced. As a result, for example, in the case where
plural data are recorded, before the reproduction of the
on-reproducing file is completed, the data recording area occupied
by the reproduced data is changed into an area where new data can
be recorded by efficiently utilizing recording areas in a data
accumulation section (13) if on-producing file exists.
Inventors: |
FUJITA, HIROYUKI; (KANAGAWA,
JP) ; ITO, NORIKAZU; (KANAGAWA, JP) ; YONEYA,
SATOSHI; (KANAGAWA, JP) ; YOSHIMOTO, MASAKAZU;
(KANAGAWA, JP) ; KATSUO, SATOSHI; (KANAGAWA,
JP) ; YUTANI, SATOSHI; (KANAGAWA, JP) ; SHIGA,
TOMOHISA; (KANAGAWA, JP) ; YOSHIKAWA, JUN;
(KANAGAWA, JP) ; SATO, KOICHI; (TOKYO,
JP) |
Correspondence
Address: |
FROMMER LAWRENCE & HAUG
745 FIFTH AVENUE- 10TH FL.
NEW YORK
NY
10151
US
|
Family ID: |
18067894 |
Appl. No.: |
09/190945 |
Filed: |
November 13, 1998 |
Current U.S.
Class: |
1/1 ;
707/999.001; G9B/27.013; G9B/27.019; G9B/27.021 |
Current CPC
Class: |
Y10S 707/99948 20130101;
G11B 27/11 20130101; G11B 2220/20 20130101; G11B 27/036 20130101;
G11B 2220/415 20130101; Y10S 707/99945 20130101; G11B 27/105
20130101; G11B 27/034 20130101; Y10S 707/99953 20130101 |
Class at
Publication: |
707/1 |
International
Class: |
G06F 007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 17, 1997 |
JP |
9-315647 |
Claims
What is claimed is:
1. A data recording and reproducing apparatus, comprising:
recording and reproducing means for recording and reproducing data
by using a non-linear accessible recording medium; control means
for controlling the recording and reproducing means so that data
recorded in the recording medium are reproduced, and for outputting
reproduction position information which represents a reproduction
position of the data in the recording medium, and a release
instruction for, while the data are being reproduced from the
recording medium, releasing an area in the recording medium where
the reproduced data have been recorded so that new data can be
recorded in the area; data management means for managing management
information which represents the area in the recording medium where
the data have been recorded and a recordable area where data can be
recorded, through changing the management information, based on the
release instruction and the reproduction position information
outputted from the control means, so that new data can be recorded
in the area corresponding to the release instruction; and
reproduction position transmission means for transmitting the
reproduction position information outputted from the control means
to the data management means.
2. A data recording and reproducing apparatus according to claim 1,
wherein the data management means changes the management
information so that information about the area in the recording
medium where the reproduced data have been recorded is deleted from
the information about the area where the data have been recorded in
the management information, and that the information about the area
where the reproduced data have been recorded is added to the
information about the recordable area in the management
information.
3. A data recording and reproducing apparatus according to claim 1,
wherein the control means outputs the release instruction into the
data management means when the release instruction is included in
the instruction for preparing the reproduction of the data recorded
in the recording medium.
4. A data recording and reproducing apparatus according to claim 1,
wherein: the management information about the area where the data
have been recorded is composed of file entry and record entry; the
file entry includes a file name of the data recorded in the
recording medium and a pointer representing a link destination to
the record entry; and the record entry includes head position data
representing an address of the head position of the area in the
recording medium where the data represented by the file entry have
been recorded, size data representing a length of the area
continuous from the address of the head position where the data
have been recorded, and pointers, when data in one file are divided
to be recorded in the recording medium, representing a link
destination between the divided areas where the divided data in the
file are recorded.
5. A data recording and reproducing apparatus according to claim 1,
wherein the management information about the recordable area
includes head position data representing an address of the head
position of a space area in the recording medium where data are not
recorded, size data representing a length of the space area
continuous from the address represented by the head position data,
and a pointer representing a link destination to a next space
area.
6. A data recording and reproducing apparatus, comprising:
recording and reproducing means for recording and reproducing data
using a non-linear accessible recording medium; and control means
for, while the data is being reproduced from the recording medium,
inputting a release instruction for releasing an area in the
recording medium where reproduced data have been recorded so that
new data can be recorded in the area, and for controlling the
recording and reproducing means through changing management
information which represents the area in the recording medium where
the data have been recorded and a recordable area where data can be
recorded, based on the inputted release instruction, so that new
data can be recorded in the area corresponding to the release
instruction.
7. A data recording and reproducing apparatus according to claim 6,
wherein the control means controls the recording and reproducing
means so that new data can be recorded in an area where the data,
which have been reproduced until the release instruction is
inputted, have been recorded.
8. A recording and reproducing apparatus according to claim 6,
wherein the control means changes the management information so
that information about the area in the recording medium where the
reproduced data have been recorded is deleted from the information
about the area where the data have been recorded in the management
information, and that the information about the area where the
reproduced data have been recorded is added to the information
about the recordable area in the management information.
9. A data recording and reproducing apparatus according to claim 8,
wherein the control means changes the management information when
the release instruction is inputted so that, when data requested by
the release instruction are divided to be recorded in plural areas
in the recording medium, the information about the area in the
recording medium where the reproduced data have been recorded is
deleted from the information about the area where the data have
been recorded in the management information, and that the
information about the area where the reproduced data have been
recorded is added to the information about the recordable area in
the management information.
10. A data recording and reproducing apparatus according to claim
6, wherein: the management information about the area where the
data have been recorded is composed of file entry and record entry;
the file entry includes a file name of data recorded in the
recording medium and a pointer representing a link destination to
the record entry; and the record entry includes head position data
representing an address of the head position of the area in the
recording medium where the data represented by the file entry have
been recorded, size data representing a length of the area
continuous from the address of the head position where the data
have been recorded, and pointers, when data in one file are divided
to be recorded in the recording medium, representing a link
destination between the divided areas where the divided data in the
file are recorded.
11. A data recording and reproducing apparatus according to claim
6, wherein the management information about the recordable area
includes head position data representing an address of the head
position of a space area in the recording medium where data are not
recorded, size data representing a length of the space area
continuous from the address represented by the head position data,
and a pointer representing a link destination to next space
area.
12. A method for recording and reproducing data by using a
non-linear accessible recording medium, including: the first step
of reproducing data recorded in the recording medium and outputting
reproduction position information which represents a reproduction
position of data in the recording medium, and a release instruction
for, while the data are being reproduced from the recording medium,
releasing an area in the recording medium where the reproduced data
have been recorded so that new data can be recorded in the area;
the second step of transmitting the reproduction position
information outputted at the first step; and the third step of
managing management information which represents the area in the
recording medium where the data have been recorded and a recordable
area where data can be recorded, through changing the management
information, based on the release instruction outputted at the
first step and the reproduction position information transmitted at
the second step, so that new data can be recorded in the area
corresponding to the release instruction.
13. A method according to claim 12, wherein the third step changes
the management information so that the information about the area
in the recording medium where the reproduced data have been
recorded is deleted from the information about the area where the
data have been recorded in the management information, and that the
information about the area where the reproduced data have been
recorded is added to the information about the recordable area in
the management information.
14. A method according to claim 12, wherein the first step, when
the release instruction is included in an instruction for preparing
the reproduction of the data recorded in the recording medium,
outputs the release instruction.
15. A method according to claim 12, wherein: the management
information about the area where the data have been recorded is
composed of file entry and record entry; the file entry includes a
file name of data recorded in the recording medium and a pointer
representing a link destination to the record entry; and the record
entry includes head position data representing an address of the
head position of the area in the recording medium where the data
represented by the file entry have been recorded, size data
representing a length of the area continuous from the address of
the head position where the data have been recorded, and pointers,
when data in one file are divided to be recorded in the recording
medium, representing a link destination between the divided areas
where the divided data in the file are recorded.
16. A method according to claim 12, wherein the management
information about the recordable area includes head position data
representing an address of the head position of a space area in the
recording medium where data are not recorded, size data
representing a length of the space area continuous from the address
represented by the head position data, and a pointer representing a
link destination to next space area.
17. A method for recording and reproducing data using a non-linear
accessible recording medium, including the steps of: reproducing
data recorded in the recording medium; and inputting a release
instruction for releasing an area in the recording medium where
reproduced data have been recorded so that new data can be recorded
in the area while the data are being reproduced from the recording
medium, and controlling recording and reproduction through changing
management information which represents the area in the recording
medium where the data have been recorded and a recordable area
where data can be recorded, based on the inputted release
instruction, so that new data can be recorded in the area
corresponding to the release instruction.
18. A method according to claim 17, wherein the controlling step
controls recording and reproduction so that new data can be
recorded in an area where reproduced data have been recorded until
the release instruction is inputted.
19. A method according to claim 17, wherein the controlling step
changes the management information so that the information about
the area in the recording medium where the reproduced data have
been recorded is deleted from the information about the area where
data have been recorded in the management information, and that the
information about the area where the reproduced data have been
recorded is added to the information about the recordable area in
the management information.
20. A method according to claim 19, wherein the controlling step
changes the management information when the release instruction is
inputted so that when data requested by the release instruction are
divided to be recorded in plural areas in the recording medium, the
information about the area in the recording medium where the
reproduced data have been recorded is deleted from the information
about the area where data have been recorded in the management
information, and that the information about the area where the
reproduced data have been recorded is added to the information
about the recordable area in the management information.
21. A method according to claim 17, wherein: the management
information about the area where the data have been recorded is
composed of file entry and record entry; the file entry includes a
file name of data stored in the recording medium and a pointer
representing a link destination to the record entry; and the record
entry includes head position data representing an address of the
head position of the area in the recording medium where the data
represented by the file entry have been recorded, size data
representing a length of the area continuous from the address of
the head position where the data have been recorded, and pointers,
when data in one file are divided to be recorded in the recording
medium, representing a link destination between the divided areas
where the divided data in the file are recorded.
22. A method according to claim 17, wherein the management
information about the recordable area includes head position data
representing an address of the head position of a space area in the
recording medium where data are not recorded, size data
representing a length of the space area continuous from the address
represented by the head position data, and a pointer representing a
link destination to next space area.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a data recording and
reproducing apparatus and method for recording and reproducing data
including audio/visual data (AV data) and the like.
[0003] 2. Description of the Related Art
[0004] In recent years, following multi-channeling for provision of
information owing to the spread of CATV (cable television) or the
like, a demand for reproducing plural data simultaneously from
single data recording and reproducing apparatus, unlike
conventional VCRs (video cassette recorder), has become higher. In
order to satisfy this demand, a data recording and reproducing
apparatus called AV (Audio/Visual) server, which records and
reproduces plural audio/visual data using a random accessible
recording and reproducing medium such as a semiconductor memory or
a hard disk, is spreading.
[0005] FIG. 27 is a functional block diagram showing a schematic
constitution of a data recording and reproducing apparatus of the
related art.
[0006] This data recording and reproducing apparatus is used as,
for example, an AV server in a broadcasting station and the like,
and it can record and reproduce data simultaneously. The data
recording and reproducing apparatus has control signal input means
101, server control means 102, data accumulation means 103, file
system management means 104, data input means 105 and data output
means 106. The control signal input means 101 inputs an input
control signal S.sub.1 for recording data and an output control
signal S.sub.2 for reproducing data thereinto from outside in real
time. The server control means 102 controls respective means in the
apparatus based on the control signals S.sub.1 and S.sub.2 inputted
into the control signal input means 101. The data accumulation
means 103 is composed of semiconductor memories, hard disks or the
like, and can record and reproduce data such as audio/visual data
thereinto/therefrom. The file system management means 104 has
management information (file system) for representing areas into
which data have been recorded and areas (space areas) into which
data can be recorded in areas of the data accumulation means 103,
and it manages the areas for data recording in the data
accumulation means 103 using the management information. The data
input means 105 inputs data D.sub.IN, to be recorded in the data
accumulation means 103, thereinto. The data output means 106
outputs data D.sub.OUT reproduced from the data accumulation means
103.
[0007] In the data recording and reproducing apparatus having such
a constitution, when the server control means 102 receives an input
control signal S.sub.1 which requests data recording from outside
via the control signal input means 101, it reserves areas which are
necessary for data recording in the data accumulation means 103
based on the management information owned by the file system
management means 104, and thereafter records and accumulates
inputted data D.sub.IN inputted via the data input means 105 into
the data accumulation means 103. Moreover, when the server control
means 102 receives an output control signal S.sub.2 which requests
data reproduction from outside via the control signal input means
101, it reproduces data from areas into which the data have been
recorded to be reproduced in the data accumulation means 103 based
on the management information owned by the file system management
means 104, and outputs the reproduced data D.sub.OUT via the data
output means 106. The aforementioned data process according to the
data recording and reproduction operations is performed per file
unit.
[0008] The following will describe one example of the procedure for
recording and reproducing plural data in a data recording and
reproducing apparatus of the related art. Here, the following
description will refer to the case where a file A whose data amount
is 40 minutes and a file B whose data amount is 30 minutes are
recorded in the data accumulation means 103 whose data recording
capacity is 60 minutes. Moreover, the following will refer to the
case where all the areas for data recording in the data
accumulation means 103 are free, and the file A and the file B are
recorded in this order into the data accumulation means 103 in the
free state, and respective recorded data are reproduced one by
one.
[0009] First, all the areas of 60 minutes for data recording in the
data accumulation means 103 before data recording are in a data
recordable state, namely, in the free state. In this state, when
the file A is recorded, the recording areas occupied by the file A
are 40 minutes, so the recordable free areas are 20 minutes.
Therefore, at this time, the file B whose data amount is 30 minutes
cannot be recorded. Next, after the file A is reproduced, all the
reproduced file A is deleted from the areas. At this time, all the
areas of the data accumulation means 103 of 60 minutes are in
recordable free state. Next, when the file B is recorded, the
recording areas occupied by the file B are 30 minutes, so the
residual recordable areas are 30 minutes.
[0010] In the aforementioned data process, in case where the file B
is desired to be recorded quickly just after the file A, it would
be expected that the file B would be recordable at the point of
time when the file A has been reproduced for 10 minutes, since
originally recordable areas (completely space areas) of 20 minutes
and the areas of the 10 minutes for which the file A has already
been reproduced make areas for 30 minutes, which would allow enough
space areas for recording the file B. Actually, however, in a data
recording and reproducing apparatus of the related art, since the
data recording and reproduction processes are performed completely
per file unit, partial deletion of data, i.e., partial release of
area, is not possible. Accordingly, the file B cannot be recorded
unless the file A is wholly deleted.
[0011] As mentioned above, in the data recording and reproducing
apparatus, when data are reproduced, for example, for broadcasting
a program, since recording areas corresponding to portions where
data have been already reproduced are not necessary, it is desired
that the above areas would be released in order to enlarge
recordable areas so that new material data may be recorded therein.
In the related art, however, release of the area has been possible
only by deleting data per file unit, so in this case, new data
would become recordable only after reproduction of data included in
one file is completed and the reproduced file is deleted. For this
reason, even if plural data are tried to be recorded, there have
been many cases where data cannot be recorded because recordable
areas are less, thereby arising a problem that efficient data
recording has been hindered.
[0012] Such a problem arises easily in the case where a relatively
great amount of material data such as programs provided by a
broadcasting station is processed in an AV server with a relatively
small capacity composed of a semiconductor memory, for example.
SUMMARY OF THE INVENTION
[0013] The present invention has been achieved with such points of
view. It therefore is an object of the present invention to provide
a data recording and reproducing apparatus and method which can
utilize areas for data recording efficiently.
[0014] A data recording and reproducing apparatus according to the
present invention comprises:
[0015] recording and reproducing means for recording and
reproducing data by using a non-linear accessible recording
medium;
[0016] control means for controlling the recording and reproducing
means so that data recorded in the recording medium are reproduced,
and for outputting reproduction position information which
represents a reproduction position of the data in the recording
medium, and a release instruction for, while the data are being
reproduced from the recording medium, releasing an area in the
recording medium where the reproduced data have been recorded so
that new data can be recorded in the area;
[0017] data management means for managing management information
which represents the area in the recording medium where the data
have been recorded and a recordable area where data can be
recorded, through changing the management information, based on the
release instruction and the reproduction position information
outputted from the control means, so that new data can be recorded
in the area corresponding to the release instruction; and
[0018] reproduction position transmission means for transmitting
the reproduction position information outputted from the control
means to the data management means.
[0019] In addition, a data recording and reproducing method
according to the present invention is a method for recording and
reproducing data by using a non-linear accessible recording medium,
which includes:
[0020] the first step of reproducing data recorded in the recording
medium and outputting reproduction position information which
represents a reproduction position of data in the recording medium,
and a release instruction for, while the data are being reproduced
from the recording medium, releasing an area in the recording
medium where the reproduced data have been recorded so that new
data can be recorded in the area;
[0021] the second step of transmitting the reproduction position
information outputted at the first step; and
[0022] the third step of managing management information which
represents the area in the recording medium where the data have
been recorded and a recordable area where data can be recorded,
through changing the management information, based on the release
instruction outputted at the first step and the reproduction
position information transmitted at the second step, so that new
data can be recorded in the area corresponding to the release
instruction.
[0023] In addition, another data recording and reproducing
apparatus according to the present invention comprises:
[0024] recording and reproducing means for recording and
reproducing data using a non-linear accessible recording medium;
and
[0025] control means for, while the data is being reproduced from
the recording medium, inputting a release instruction for releasing
an area in the recording medium where reproduced data have been
recorded so that new data can be recorded in the area, and for
controlling the recording and reproducing means through changing
management information which represents the area in the recording
medium where the data have been recorded and a recordable area
where data can be recorded, based on the inputted release
instruction, so that new data can be recorded in the area
corresponding to the release instruction.
[0026] In addition, another data recording and reproducing method
according to the present invention is a method for recording and
reproducing data by using a non-linear accessible recording medium,
which includes the steps of:
[0027] reproducing data recorded in the recording medium; and
[0028] inputting a release instruction for releasing an area in the
recording medium where reproduced data have been recorded so that
new data can be recorded in the area while the data are being
reproduced from the recording medium, and controlling recording and
reproduction through changing management information which
represents the area in the recording medium where the data have
been recorded and a recordable area where data can be recorded,
based on the inputted release instruction, so that new data can be
recorded in the area corresponding to the release instruction.
[0029] In another data recording and reproducing apparatus or
method according to the present invention, when the release
instruction is inputted for, while the data are being reproduced
from the recording medium, releasing the area in the recording
medium where the reproduced data have been recorded so that new
data can be recorded in the area, the management information, which
represents the area in the recording medium where data have been
recorded and the area where data can be recorded, is changed based
on the inputted release instruction, thereby controlling the
recording and reproduction so that new data can be recorded in the
area corresponding to the release instruction.
[0030] The above and further objects and features of the present
invention will more fully be apparent from the following detailed
description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 is a block diagram showing a schematic constitution
of a data recording and reproducing apparatus according to a first
embodiment of the present invention.
[0032] FIG. 2 is a functional block diagram for describing
functions of the data recording and reproducing apparatus shown in
FIG. 1.
[0033] FIGS. 3A through 3C are explanatory diagrams showing one
example of management information to be managed in the data
recording and reproducing apparatus shown in FIG. 1.
[0034] FIGS. 4A through 4D are explanatory diagrams showing a
particular use example of the management information in shown in
FIG. 3.
[0035] FIG. 5 is a flow chart for describing a recording operation
of the data recording and reproducing apparatus shown in FIG.
1.
[0036] FIG. 6 is a flow chart for describing a reproduction
operation of the data recording and reproducing apparatus shown in
FIG. 1.
[0037] FIGS. 7A and 7B are explanatory diagrams showing examples of
the operations based on control signals in the data recording and
reproducing apparatus shown in FIG. 1.
[0038] FIGS. 8A through 8D are explanatory diagrams showing a
change in recording areas according to the operations shown in
FIGS. 7A and 7B.
[0039] FIGS. 9A through 9D are explanatory diagrams showing a
change in the management information according to the operations
shown in FIGS. 7A and 7B.
[0040] FIG. 10 is a flow chart showing a transmission operation of
the control signals in the case where the data recording and
reproducing apparatus shown in FIG. 1 performs a process according
to an occasional release instruction.
[0041] FIG. 11 is a flow chart for explaining an operation to be
performed in the case where server control means of the data
recording and reproducing apparatus shown in FIG. 1 performs an
occasional release process.
[0042] FIG. 12 is a flow chart for explaining an operation in the
case where file system management means of the data recording and
reproducing apparatus shown in FIG. 1 performs the occasional
release process.
[0043] FIGS. 13A and 13B are explanatory diagrams showing
particular examples of a change in the recording areas according to
the operation shown in FIG. 12.
[0044] FIGS. 14A and 14B are explanatory diagrams showing
particular examples of a change in the management information
according to the operation shown in FIG. 12.
[0045] FIGS. 15A and 15B are explanatory diagrams showing examples
of the operation which is performed by the data recording and
reproducing apparatus shown in FIG. 1 based on the control signals
including the occasional release instruction.
[0046] FIGS. 16A through 16D are explanatory diagrams showing a
change in the recording areas according to the operations shown in
FIG. 15.
[0047] FIG. 17 is an explanatory diagram showing a change in the
management information according to the operations shown in FIG.
15.
[0048] FIGS. 18A and 18B are explanatory diagrams for comparing
changes in the recordable areas in the operations shown in FIGS. 7A
and 7B and the operations shown in FIGS. 15A and 15B.
[0049] FIG. 19 is a flow chart showing an operation in the case
where the control signal including the release instruction is
transmitted from outside to the data recording and reproducing
apparatus shown in FIG. 1.
[0050] FIG. 20 is a flow chart for explaining an operation which is
performed when the data recording and reproducing apparatus shown
in FIG. 1 receives the release instruction.
[0051] FIGS. 21A through 21C are explanatory diagrams showing
particular examples of a change in areas for data recording
according to the operation shown in FIG. 20.
[0052] FIGS. 22A through 22C are explanatory diagrams showing
particular examples of a change in the management information
according to the operation shown in FIG. 20.
[0053] FIGS. 23A and 23B are explanatory diagrams showing examples
of operations of the data recording and reproducing apparatus shown
in FIG. 1 based on the control signals.
[0054] FIGS. 24A through 24D are explanatory diagrams showing a
change in areas for data recording according to the operations
shown in FIGS. 23A and 23B.
[0055] FIGS. 25A through 25D are explanatory diagrams showing a
change in the management information according to the operations
shown in FIGS. 23A and 23B.
[0056] FIGS. 26A through 26D are explanatory diagrams for comparing
changes in recordable areas in the operations shown in FIGS. 7A and
7B and the operations shown in FIGS. 23A and 23B.
[0057] FIG. 27 is a block diagram showing a constitution of a data
recording and reproducing apparatus of the related art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0058] There will be detailed below preferred embodiments of the
present invention with reference to the diagrams.
[0059] FIG. 1 is a block diagram showing a constitution of a data
recording and reproducing apparatus according to a first embodiment
of the present invention. Moreover, FIG. 2 is a functional block
diagram showing functions of the data recording and reproducing
apparatus 10 shown in FIG. 1.
[0060] The data recording and reproducing apparatus 10 according to
the present embodiment can record and reproduce data
simultaneously. As shown in FIG. 2, the data recording and
reproducing apparatus 10 has, as functional blocks, control signal
input means 41, server control means 42, data accumulation means
43, file system management means 44, data input means 45, data
output means 46 and reproduction position transmission means 47.
The control signal input means 41 inputs an input control signal
S.sub.1 used for recording data and an output control signal
S.sub.2 used for reproducing the data in real time thereinto from
outside. The server control means 42 controls respective means in
the apparatus based on the control signals S.sub.1 and S.sub.2
inputted into the control signal input means 41. The data
accumulation means 43 is composed of a semiconductor memory, a hard
disk and the like, and can record and reproduce data such as
audio/visual data thereinto/therefrom. The file system management
means 44 has management information (file system) for representing
areas into which data have been recorded and areas into which data
can be recorded in areas of the data accumulation means 43, and it
manages the areas for data recording in the data accumulation means
43 using the management information. The data input means 45 inputs
data D.sub.IN, to be recorded in the data accumulation means 43,
thereinto. The data output means 46 outputs data D.sub.OUT
reproduced from the data accumulation means 43. The reproduction
position transmission means 47 transmits information about a data
reproduction position in the data accumulation means 43 to the file
system management means 44 anytime while data in an arbitrary file
in the data recording areas of the data accumulation means 43 are
being reproduced. Here, the file system management means 44
corresponds to data management means of the present invention.
Moreover, the server control means 42 corresponds to control means
of the present invention.
[0061] In the data recording and reproducing apparatus 10, when the
server control means 42 receives an input control signal S.sub.1
which requests data recording from outside via the control signal
input means 41, it reserves areas which are necessary for data
recording in the data accumulation means 43 based on the management
information owned by the file system management means 44, and
thereafter records and accumulates inputted data D.sub.IN inputted
via the data input means 45 into the data accumulation means 43.
Moreover, when the server control means 42 receives an output
control signal S.sub.2 which requests data reproduction from
outside via the control signal input means 41, it reproduces data
from areas into which the data have been recorded to be reproduced
in the data accumulation means 43 based on the management
information owned by the file system management means 44, and
outputs the reproduced data D.sub.OUT from the data accumulation
means 43 via the data output means 46.
[0062] In order to realize the aforementioned function, the data
recording and reproducing apparatus 10 according to the present
embodiment, as shown in FIG. 1, has a control signal interface
(hereinafter, the interface is represented by IF) 11, a control
section 12, a data accumulation section 13, a data input IF 14 and
a data output IF 15. These components are interconnected by an
internal bus 31. The data recording and reproducing apparatus 10 is
used as an AV server which deals with audio/visual data (AV data)
in a broadcasting station or the like, and the AV server records
and reproduces AV data or the like inputted from VCR (Video
cassette recorder) 20 or the like under control by a server
controller 30.
[0063] The server controller 30 transmits control signals S.sub.1
and S.sub.2 to the control signal IF 11 and controls the recording
and reproduction operations of the data recording and reproducing
apparatus 10. For example, when the server controller 30 requests
the data recording and reproducing apparatus 10 to reproduce data,
it transmits PLAY_OPEN command for requesting preparation of data
reproduction as an input control signal S.sub.1. Moreover, while
data in an arbitrary file in the data accumulation section 13 are
being reproduced, the server controller 30 changes management
information as occasional demands so that areas where reproduced
data of the on-reproducing data in the file have been recorded
become recordable areas, and adds a release instruction for
immediately releasing, whenever necessary, the areas where the data
have been recorded (referred to as "occasional release instruction"
throughout the present specification) to the PLAY_OPEN command so
as to transmit it. Moreover, the server controller 30 controls the
VCR 20 to input data D.sub.IN to be recorded into the data input IF
14. Here, in the case where, for example, the data recording and
reproducing apparatus 10 is utilized in a broadcasting station or
the like, the control signals S.sub.1 and S.sub.2 may be
transmitted from the server controller 30 automatically according
to a broadcasting program, or based on remote control through a
remote controller (not shown) or the like connected with the server
controller 30.
[0064] The data input IF 14 realizes the function of the data input
means 45, and removes added data such as synchronized data inputted
from the VCR 20 from the data D.sub.IN so as to make net data.
Moreover, the data input IF 14 compresses data as occasional
demands. The data inputted into the data input IF 14 are
transmitted via the internal bus 31 to the data accumulation
section 13 so as to be accumulated therein under the control by the
control section 12.
[0065] The data accumulation section 13 realizes the function of
the data accumulation means 43, and it records and stores data
captured from the data input IF 14 therein. Moreover, the data
accumulation section 13 reproduces the accumulated data so as to
transmit them to the data output IF 15. The data accumulation
section 13 is composed of a semiconductor memory directly connected
with the internal bus 31, non-linear accessible HDD (hard disk
drive) connected via an interface according to SCSI (Small Computer
System Interface) standard or the like (for example, RAID (Redutant
Arrays of Inexpensive Disks) which is combination of plural HDDs),
and it can record and reproduce data.
[0066] The data output IF 15 realizes the function of the data
output means 46, and it outputs data D.sub.OUT, which are obtained
by adding additional data, such as synchronizing signals, to net
data accumulated by the data accumulation section 13. Moreover, the
data output IF 15 expands net data as occasional demands.
[0067] The control signal IF 11 realizes the function of the
control signal input means 41, and it transmits real-time control
signals S.sub.1 and S.sub.2 from the server controller 30 to the
control section 12.
[0068] The control section 12 realizes the functions of the server
control means 42 and the file system management means 44, and it
has a CPU (Central Processing Unit) 21, a ROM (Read Only Memory) 22
and a RAM (Random Access Memory) 23. The RAM 23 includes a work
area 23a, a management information storage area 23b and a
reproduction position storage area 23c as storage areas.
[0069] When the CPU 21 executes various programs stored in the ROM
22 using the work area 23a of the RAM 23, the control section 12
controls the respective components of the data recording and
reproducing apparatus 10 so as to realize the functions of the
server control means 42 and the file system management means 44.
For example, the control section 12 controls the data input IF 14,
the data accumulation section 13 and the data output IF 15 based on
an external instruction from the control signal IF 11 and the
management information stored in the management information storage
area 23b of the RAM 23. As a result, the control section 12 records
the data inputted from the data input IF 14 into desired areas
(address) in the data accumulation section 13 and reads out the
data in a specified file from the data accumulation section 13 so
as to output the data from the data output IF 15. Moreover, the
control section 12 creates management information to be stored in
the management information storage area 23b. Here, the control
section 12 controls the data accumulation section 13 to record and
reproduce data per file unit as long as a special instruction is
not given from outside.
[0070] Moreover, when the occasional release instruction is added
to the PLAY_OPEN command from outside (server controller 30) for
requesting preparation of data reproduction, the control section 12
as the file system management means 44 corrects (changes) the
management information so that areas occupied by the reproduced
data in the data recording areas occupied by on-reproducing file in
the data accumulation section 13 become new data recordable areas
whenever a file is reproduced. Moreover, when the occasional
release instruction is added to the PLAY_OPEN command, the control
section 12 as the server control means 42 writes reproduction
position information of on-reproducing file in the data recording
areas of the data accumulation section 13 into the reproduction
position storage area 23c of the RAM 23 whenever a file is
reproduced. In the case where, for example, the data accumulated in
the data accumulation section 13 are AV data compressed according
to the MPEG (Moving Picture Experts Group) standard, the writing of
the reproduction position information is carried out per GOP (Group
Of Pictures).
[0071] Furthermore, the CPU 21 stores the management information
for managing recording areas in the data accumulation section 13
into the management information storage area 23b of the RAM 23 and
manages it therein, so that the control section 12 realizes the
function of the file system management means 44. The control
section 12 as the file system management means 44 manages
information about as to addresses in the data accumulation section
13 into which data have been recorded, space area information in
the data accumulation section 13 and the like. The control section
12 as the file system management means 44 is actuated according to
instructions for requesting "area information for file
reproduction" and "space area information for file recording" from
the server control means 42, and transmits information according to
the instruction to the server control means 42.
[0072] In addition, when the server control means 42 has received
the occasional release instruction, the control section 12 as the
file system management means 44 successively reads the reproduction
position information written into the reproduction position storage
area 23c as the reproduction position transmission means 47 and
changes the management information based on the read reproduction
position information. As a result, the control section 12 changes
reproduced data recording areas occupied by the reproduced data
into new data recordable areas whenever a file is reproduced. In
such a manner, when the file system management means 44 obtains the
reproduction position information of the on-producing file via the
reproduction position transmission means 47, the process for
transmitting a reproduction position performed by the server
control means 42 and the process for immediately releasing,
whenever necessary, the areas where data have been recorded
(referred to as "occasional release process" throughout the present
specification) in a file based on the reproduction position
information performed by the file system management means 44 can be
executed asynchronously. Therefore, the occasional release process
can be executed without influencing performance of the whole data
recording and reproducing apparatus 10. Here, when the processes
for reproduction position transmission in the file system
management means 44 and the server control means 42 are executed
asynchronously, real-time characteristic between the occasional
release process and the reproduction operation is deteriorated.
However, since it is not necessary that the occasional release
process actually coincides with the reproduction operation
completely, the deterioration of real-time characteristic can be
neglected actually. Here, the process for changing the management
information according to the occasional release instruction
executed by the control section 12 as the file system management
means 44 will be further detailed in the explanation of the
operation, mentioned later.
[0073] The following will describe the management information which
is managed in the file system management means 44 with reference to
FIGS. 3 and 4.
[0074] The management information is composed of, for example, file
entry (FE) shown in FIG. 3A, record entry (RE) shown in FIG. 3B and
free space list (FSL) shown in FIG. 3C. The file entry and the
record entry of the management information are used for managing
data recorded in the data accumulation means 43 (data accumulation
section 13) per file unit, and they are linked with each other.
[0075] The file entry is composed of two items, namely, file names
of recorded data and pointers for linking with the first record
entry having the recording area information corresponding to the
file names.
[0076] The record entry is used for showing areas in address space
of the data accumulation means 43 where the data of the file name
in the linked file entry are recorded. The record entry is composed
of three items, namely, head position data representing an address
of the head position of the areas where data have been recorded,
size data representing a length (size) of the areas continuous with
the address represented by the head position data, and a pointer to
the record entry representing areas where next data in the same
file have been recorded. In the case where all data included in one
file are recorded in continuous areas in the address space of the
data accumulation means 43, the record entry is made up
independently. Moreover, in the case where data included in one
file are divided into plural parts to be recorded in areas in the
address space of the data accumulation means 43, the record entry
is composed of plural record entry lists corresponding to the
divided areas. In this case, plural record entries are linked
successively by the item "pointer to next record entry". In the
case where a record entry corresponding to the next area where data
have been recorded does not exist, "EOF (End Of File)", which
represents end of data included in one file is described in the
item "pointer to next record entry".
[0077] The free space list represents information about space areas
(free space: recordable areas including unused areas where data can
be recorded) in the data accumulation means 43. The free space list
is composed of three items, namely, head position data representing
an address of a head position of space areas, size data
representing a length of the space areas continuous with the
address represented by the head position data, and a pointer
representing a link destination of next space area in the free
space list. In the case where the space area is a continuous area
in the address space of the data accumulation means 43, the free
space list is made up independently. Moreover, in the case where
the space area is divided into plural areas in the address space of
the data accumulation means 43, the free space list is composed of
plural free space lists corresponding to the divided space areas.
In this case, plural free space lists are linked successively by
the item "pointer to next free space list". Here, in the case where
the free space list corresponding to next space area does not
exist, "EOL (End Of List)", which represents end of the space area
included in the address space of the data accumulation means 43, is
described in the item "pointer to next free space list".
[0078] The following will describe a particular use example of the
management information shown in FIG. 3 with reference to FIG. 4.
FIG. 4A shows the address space in the data accumulation means 43
(data accumulation section 13), and FIGS. 4B, 4C and 4D show the
management information.
[0079] As shown in FIG. 4A, for example, the data in the file A are
recorded continuously in one area of address 0 to 149 in the
address space of the data accumulation means 43, and the data in
the file B are recorded divisionally in two areas of address 200 to
299 and address 350 to 424. At this time, the space areas in the
address space of the data accumulation means 43 is three-divided
areas of address 150 to 199, address 300 to 349 and address 425 to
499. Here, in FIG. 4, the addresses are represented by number of a
block which is a group of data with a predetermined unit.
[0080] The information corresponding to the area where the file A
has been recorded in the area information shown in FIG. 4A is
represented as shown in FIG. 4B by using file entry and the record
entry shown in FIGS. 3A and 3B. Namely, "A" is described in the
item of the file name in the file entry (FE). "0" and "150" are
described respectively in the items of the head position data and
the size data in the record entry (RE) linked by the pointer of the
file entry. Moreover, "EOF", which represents end of data, is
described in the item of the pointer to next record entry in the
record entry.
[0081] The information corresponding to the areas where the file B
has been recorded in the area information shown in FIG. 4A is
represented as shown in FIG. 4C by using file entry and the record
entry shown in FIGS. 3A and 3B. Namely, "B" is described in the
item of the file name in the file entry (FE). "200" and "100" are
described respectively in the items of the head position data and
the size data in the record entry (RE-1) linked by the pointer of
the file entry. Moreover, "350" and "75" are described respectively
in the items of the head position data and the size data in the
next record entry (RE-2) linked by the pointer of the record entry
(RE-1). Moreover, "EOF" representing end of data is described in
the item of the point to a record entry next to the record entry
(RE-2).
[0082] The information corresponding to the space areas in the area
information shown in FIG. 4A is represented as shown in FIG. 4D by
using free space list shown in FIG. 3C. Namely, "150" and "50" are
described respectively in the items of the head position data and
the size data in the first free space list (FSL-1). Moreover, "300"
and "50" are described respectively in the items of the head
position data and the size data in the next free space list (FSL-2)
linked by the pointer of the free space list (FSL-1). Further,
"425" and "75" are described respectively in the items of the head
position data and the size data in a next free space list (FSL-3)
linked by the pointer of the free space list (FSL-2). Moreover,
"EOL" representing end of list is described in the item of the
pointer to free space list next to the free space list (FSL-3).
[0083] The following will describe the operation of the data
recording and reproducing apparatus 10 having the above
constitution.
[0084] First, the description will refer to the operation in
absence of the occasional release instruction.
[0085] FIG. 5 is a flow chart for describing the data recording
operation. First, when an instruction (REC_OPEN command) for
requesting preparation of recording of data in a predetermined file
(creation of file entry, or the like) is inputted as the input
control signal S.sub.1 from outside (server controller 30) into the
control signal input means 41 (control signal IF 11), the control
signal input means 41 transmits the signal S.sub.1 to the server
control means 42 (control section 12) (S101). Here, the signal
S.sub.1 inputted into the control signal input means 41 includes
information of such as a file name and size of data to be
recorded.
[0086] When the server control means 42 receives the REC_OPEN
command for requesting preparation of data recording, it transmits
an area reserve request instruction for reserving an area for data
recording in the data accumulation means 43 (data accumulation
section 13) to the file system management means 44 (S102). When the
file system management means 44 receives the area reserve request
instruction, it reserves an area for data recording based on the
free space list which is data-recordable space area information
included in the management information (FIG. 3) owned by itself
(management information storage area 23b of the RAM 23), and
transmits the reserved area information to the server control means
42 (S103).
[0087] Next, when a recording instruction for actually starting the
data recording is inputted as the input control signal S.sub.1 from
outside (server controller 30) into the control signal input means
41, the control signal input means 41 transmits the signal S.sub.1
to the server control means 42 (S104). Upon receiving the recording
instruction, the server control means 42 controls the data input
means 45 and the data accumulation means 43 so as to record data
D.sub.IN to be recorded, which has been inputted from outside (VCR
20) via the data input means 45, into the reserved area of the data
accumulation means 43 and to accumulate the data D.sub.IN therein
(S105).
[0088] Next, when a recording halt instruction for halting data
recording is inputted as the input control signal S.sub.1 from
outside (server controller 30) into the control signal input means
41, the control signal input means 41 transmits the signal S.sub.1
to the server control means 42 (S106). Upon receiving the recording
halt instruction, the server control means 42 controls the data
accumulation means 43 so as to halt the data recording operation
(S107).
[0089] Next, a close instruction, which is for closing the file
after correcting (updating) the management information owned by the
file system management means 44, is inputted as the input control
signal S.sub.1 from outside (server controller 30) into the control
signal input means 41, and the signal S.sub.1 is transmitted to the
server control means 42 (S108). Upon receiving the close
instruction, the server control means 42 transmits the close
instruction to the file system management means 44 (S109). Upon
receiving the close instruction, the file system management means
44 updates the management information (FIG. 3) owned by itself and
closes the file (S110). As a result, the recording operation is
terminated. Here, in the file system management means 44, as the
file closing process, for example, a difference between the first
reserved area for data recording and the area where the data have
been actually recorded is adjusted.
[0090] The following will describe the data reproduction operation
with reference to FIG. 6. When an instruction (PLAY_OPEN command)
for requesting preparation of reproduction of data in a
predetermined file is inputted as the output control signal S.sub.2
from outside (server controller 30) into the control signal input
means 41 (control signal IF 11), the control signal input means 41
transmits the signal S.sub.2 to the server control means 42
(control section 12) (S201). Here, the signal S.sub.2 to be
inputted to the control signal input means 41 includes information
about a file name or the like for specifying the data to be
reproduced.
[0091] Upon receiving the PLAY_OPEN command for requesting
preparation of data reproduction, the server control means 42
transmits an area information request instruction which requests
information representing an area of the data accumulation means 43
(data accumulation section 13) where the data in the predetermined
data have been recorded, to the file system management means 44
(S202). Upon receiving the area information request instruction,
the file system management means 44 retrieves the information about
the area where the data in the specified data have been recorded
based on the management information (FIG. 3) owned by itself
(management information storage area 23b of the RAM 23), and
transmits the retrieved area information to the server control
means 42 (S203).
[0092] Next, when a reproduction instruction for actually starting
the data reproduction is inputted as the output control signal
S.sub.2 from outside (server controller 30) into the control signal
input means 41, the control signal input means 41 transmits the
signal S.sub.2 to the server control means 42 (S204). Upon
receiving the reproduction instruction, the server control means 42
controls the data output means 46 (data output IF 15) and the data
accumulation means 43 so as to reproduce data in a specified file
from the data accumulation means 43 based on the area information
obtained from the file system management means 44 and to output the
reproduced data as data D.sub.OUT from the data output means 46
(S205).
[0093] Next, when a reproduction halt instruction for halting data
reproduction is inputted as the output control signal S.sub.2 from
outside (server controller 30) into the control signal input means
41, the control signal input means 41 transmits the signal S.sub.2
to the server control means 42 (S206). Upon receiving the
reproduction halt instruction, the server control means 42 controls
the data accumulation means 43 so as to halt the data reproduction
operation (S207).
[0094] Next, a close instruction for terminating the file process
is inputted as the output control signal S.sub.2 from outside
(server controller 30) into the control signal input means 41, and
the signal S.sub.2 is transmitted to the server control means 42
(S208). Upon receiving the close instruction, the server control
means 42 transmits the close instruction to the file system
management means 44 (S209). Upon receiving the close instruction,
the file system management means 44 closes the file (S210) so that
the reproduction operation is terminated.
[0095] The following will describe an example of the operation of
the data recording and reproducing apparatus 10 involving recording
of plural data with reference to FIGS. 7 through 9. Here, the
description will be given as to the case where the file A whose
data amount is 40 minutes and the file B whose data amount is 30
minutes are recorded in the data accumulation means 43 (data
accumulation section 13) whose data recording capacity is 60
minutes. In addition, there considers the case where first all the
areas for data recording in the data accumulation means 43 are
free, and the file A and the file B are recorded in this order in
the data accumulation means 43 in the free state, and the recorded
data are reproduced one by one.
[0096] FIG. 7 is an explanatory diagram showing the operation of
the data recording and reproducing apparatus 10 in the case where
the file A and the file B are recorded and reproduced. FIG. 7A
shows the operation based on the input control signal S.sub.1, and
FIG. 7B shows the operation based on the output control signal
S.sub.2. FIG. 8 shows a change in areas for data recording in the
data accumulation means 43 (data accumulation section 13) according
to the operations shown in FIG. 7. FIG. 9 shows a change in the
management information owned by the file system management means 44
according to the operations shown in FIG. 7. Here, in FIGS. 8 and
9, for convenience, address coincides with "minute".
[0097] First, as shown in FIG. 7A, the data recording and
reproducing apparatus 10 receives an instruction (REC_OPEN "A"
command) for requesting preparation of recording of the file A as
the input control signal S.sub.1 from outside (server controller
30) (S301). At this time, as shown in FIG. 8A, all the areas for
data recording in the data accumulation means 43 are free, and a
recordable data amount D.sub.f1 is 60 minutes in time. Moreover,
the management information owned by the file system management
means 44 at this time is represented as shown in FIG. 9A by using
free space lists (FSL) shown in FIG. 3. Namely, "0" and "60" are
described respectively in the items of the head position data and
the size data, and "EOL" representing end of list is described in
the item of the pointer to next free space list.
[0098] Upon receiving the REC_OPEN "A" command, the data recording
and reproducing apparatus 10 reserves an area for recording the
file A only by 40 minutes based on the management information owned
by the file system management means 44 as shown in FIG. 8B. At this
time, the file system management means 44 of the data recording and
reproducing apparatus 10 corrects (updates) the management
information according to the reservation of the area for recording
the file A. The corrected management information is as shown in
FIG. 9B. When the management information is corrected in such a
manner, an amount D.sub.f2 of data except for the file A to be
recordable in the data accumulation means 43 becomes 20 minutes in
time.
[0099] The information of the management information shown in FIG.
9B corresponding to the area for recording the file A is
represented by file entry (FE) and record entry (RE). Namely, "A"
is described in the item of the file name in the file entry, and
"0" and "40" are described respectively in the items of the head
position data and the size data in the record entry linked with the
file entry. Moreover, "EOF" representing end of data is described
in the item of the pointer to next record entry. Moreover, "40" and
"20" are described respectively in the items of the head position
data and the size data in the free space list showing the space
areas, and "EOL" representing end of list is described in the item
of the pointer to next free space list.
[0100] The data recording and reproducing apparatus 10 receives the
REC_OPEN "A" command and reserves the area for recording the file A
and corrects the management information. Thereafter, upon receiving
from outside (server controller 30) the recording instruction for
actually starting the recording of the file A, the data recording
and reproducing apparatus 10 starts the recording of the data in
the file A into the reserved area of the data accumulation means 43
(S302).
[0101] Next, upon receiving from outside (server controller 30) the
recording halt instruction for halting the recording of the file A,
the data recording and reproducing apparatus 10 halts the operation
for recording the file A (S303).
[0102] In addition, upon receiving the close instruction from
outside (server controller 30), the data recording and reproducing
apparatus 10 corrects (updates) the management information owned by
the file system management means 44 so as to close the file (S304).
Here, in the file system management means 44, as the file close
process, there exists a difference between the management
information created first by the server control means 42 and the
area where the data have been actually recorded, the difference is
adjusted. Here, the file A is recorded in accordance with the
management information first created as shown in FIG. 8B.
[0103] As mentioned above, when the file A is recorded, as shown in
FIG. 8B, the area in the data accumulation means 43 occupied by the
file A is 40 minutes, and the recordable area where another data
can be recorded is 20 minutes. Therefore, at this time the file B
whose data amount is 30 minutes cannot be recorded. Accordingly,
after the file A is reproduced, it is necessary to delete the whole
reproduced file so as to create a space area.
[0104] As shown in FIG. 7B, in the case where the file A is
reproduced, the data recording and reproducing apparatus 10
receives the instruction for requesting the preparation of file A
reproduction (PLAY_OPEN "A" command) as the output control signal
S.sub.2 from outside (server controller 30) (S401).
[0105] Upon receiving the PLAY_OPEN "A" command, the data recording
and reproducing apparatus 10 retrieves the area information for
reproducing the file A based on the management information owned by
the file system management means 44. Next, upon receiving from
outside (server controller 30) the reproduction instruction for
actually starting the reproduction of the file A, the data
recording and reproducing apparatus 10 starts reproduction of the
data in the file A from the data accumulation means 43 based on the
retrieved area information (S402).
[0106] Next, upon receiving from outside (server controller 30) the
reproduction halt instruction for halting reproduction of the file
A, the data recording and reproducing apparatus 10 halts the
reproduction of the file A (S403).
[0107] In addition, upon receiving the close instruction from
outside (server controller 30), the data recording and reproducing
apparatus 10 closes the file (S404), and ends the reproduction
operation of the file A.
[0108] Next, as shown in FIG. 7A, upon receiving a file A deleting
instruction from outside (server controller 30) after the
reproduction process of the file A is ended, the data recording and
reproducing apparatus 10 deletes the whole reproduced file A from
the data accumulation means 43 (S305). At this time, the area for
data recording in the data accumulation means 43 is, as shown in
FIG. 8C, free, and a recordable data amount D.sub.f3 is 60 minutes
in time. Therefore, the file B of 30 minutes can be recorded at
this time. Moreover, the file system management means 44 of the
data recording and reproducing apparatus 10 corrects (updates) the
management information according to the deletion of file A. The
corrected management information is, as shown in FIG. 9C,
represented only by free space list, and "0" and "60" are described
respectively in the items of the head position data and the size
data in the free space list. Moreover, "EOL" representing end of
list is described in the item of the pointer to the next free space
list.
[0109] Next, the data recording and reproducing apparatus 10
receives the instruction for requesting the preparation of
recording the file B (REC_OPEN "B" command) as the input control
signal S.sub.1 from outside (server controller 30) (S306).
[0110] Upon receiving the REC_OPEN "B" command, the data recording
and reproducing apparatus 10 reserves an area for recording the
file B by 30 minutes, for example, as shown in FIG. 8D, based on
the management information owned by the file system management
means 44. At this time, the data recording and reproducing
apparatus 10 corrects (updates) the management information
according to the reservation of the area for recording the file B.
The corrected management information is as shown in FIG. 9D. When
the management information is corrected in such a manner, a data
amount D.sub.f4 in the data accumulation means 43 where data except
for those in the file B can be recorded is 30 minutes in time.
[0111] The information corresponding to the area for recording the
file B in the management information shown in FIG. 9D is
represented by file entry (FE) and record entry (RE). Namely, "B"
is described in the item of the file name in the file entry, and
"0" and "30" are described respectively in the items of the head
position data and the size data in the record entry linked with the
file entry. Moreover, "EOF" representing end of data is described
in the item of the pointer to the next record entry. Moreover, "30"
and "30" are described respectively in the items of the head
position data and the size data in the free space list representing
a space area, and "EOL" representing end of list is described in
the item of the pointer to the next free space list.
[0112] After receiving the REC_OPEN "B" command, reserving the area
for recording the file B and correcting the management information,
when the data recording and reproducing apparatus 10 has received
from outside (server controller 30) a recording instruction for
actually starting the recording of the file B, it starts the
recording of the data in the file B into the reserved area of the
data accumulation means 43 (S307).
[0113] Next, upon receiving from outside (server controller 30) the
recording halt instruction for halting the recording of the file B,
the data recording and reproducing apparatus 10 halts the operation
for recording the file B (S308).
[0114] In addition, upon receiving the close instruction from
outside (server controller 30), the data recording and reproducing
apparatus 10 corrects (updates) the management information owned by
the file system management means 44 and closes the file (S309), and
ends the process for recording the file A and the file B.
[0115] The file A and the file B are recorded and reproduced in the
above manner. In these processes, since the recordable area
(completely space area) of 20 minutes and the area of 10 minutes
where the file A has been reproduced make the area of 30 minutes at
the time when the file A is reproduced for 10 minutes, from the
time when the file A is reproduced for 10 minutes, sufficient space
area for recording the file B is generated in the data accumulation
means 43 (data accumulation section 13), and thus the file B can be
properly recorded. Therefore, in the present embodiment, in the
case where the occasional release instruction is added to the
PLAY_OPEN command from outside (server controller 30) for
requesting preparation of data reproduction, the management
information is changed so that the reproduced data recording area
occupied by the reproduced data in the data recording area occupied
by the on-reproducing file may become a recordable area where new
data can be recorded.
[0116] The following will describe the operation including a
process according to the occasional release instruction.
[0117] As mentioned above, the occasional release instruction is
added to the REC_OPEN command for preparing data reproduction. When
the occasional release instruction is added, the reproduced data
are successively deleted (released) from the recording area in the
data accumulation section 13. The following detailed operation of
the occasional release instruction will be given as to the REC_OPEN
process for transmitting the recording instruction from the server
controller 30 to the data recording and reproducing apparatus 10
when data are reproduced while the recording area is being released
at any time in the data recording and reproducing apparatus 10.
Next, the description will be given as to the processes in the
server control means 42 and in the file system management means 44
when they receive the reproduction instruction (PLAY_OPEN command)
including the occasional release instruction.
[0118] First, with reference to FIG. 10, the description will be
given as to the operation that the server controller 30 transmits
the REC_OPEN command for requesting the preparation of data
recording to the data recording and reproducing apparatus 10 in the
case where the data recording and reproducing apparatus 10
accompanies the process according to the occasional release
instruction. In the case where the server controller 30 transmits
the REC_OPEN command, first the server controller 30 judges as to
whether or not a data amount (recording time) of a file to be
recorded exceeds the space area in the data recording and
reproducing apparatus 10 (S501). When the data amount does not
exceed the space area in the data recording and reproducing
apparatus 10 (S501;N), the server controller 30 transmits the
REC_OPEN command to the data recording and reproducing apparatus 10
(S506), and ends the process.
[0119] Meanwhile, when the data amount exceeds the space area in
the data recording and reproducing apparatus 10 (S501;Y), the
server controller 30 judges as to whether or not the data
accumulation means 43 (data accumulation section 13) is reproducing
a file for which an occasional release process is to be performed
in the data recording and reproducing apparatus 10 (S502). Here,
when the file is reproduced without the occasional release process
in the data recording and reproducing apparatus 10 (S502;N), the
server controller 30 judges that the recording request is
unsuccessful (S507) and ends the process.
[0120] In addition, in the case where the data recording and
reproducing apparatus 10 is performing a file reproduction
including the occasional release process (S502;Y), the server
controller 30 subtracts the space area in the data accumulation
means 43 and the time for file reproduction including the
occasional release process from the data amount (recording time) of
the file to be recorded (S503). Next, the server controller 30
judges as to whether or not the obtained value T exceeds 0, namely,
the recording area for the file to be recorded is reserved (S504).
Here, all the recording time, the space area and the time for file
reproduction including the occasional release process are grasped
by the server controller 30.
[0121] When the calculated value T does not exceed 0, namely, the
recording area to be recorded has been already reserved (S504;N),
the server controller 30 transmits the REC_OPEN command to the data
recording and reproducing apparatus 10 (S506), and ends the
process. Moreover, when the calculated value T exceeds 0, namely,
the recording area to be recorded has not been reserved (S504;Y),
the server controller 30 waits until the time corresponding to the
calculated value T passes (S505), and thereafter transmits the
REC_OPEN command to the data recording and reproducing apparatus 10
(S506) so as to end the process.
[0122] The following will describe the operation performed by the
data recording and reproducing apparatus 10 when it has received
the occasional release instruction with reference to FIGS. 11 and
12. The description of this operation will be divided into two
parts, the operation by the server control means 42 and the
operation by the file system management means 44.
[0123] FIG. 11 is a flow chart showing the operation including the
occasional release process in the server control means 42 (control
section 12). As shown in this diagram, when the server control
means 42 has received the PLAY_OPEN command for requesting
preparation of reproduction of data in a predetermined file
including the occasional release instruction, from outside (server
controller 30) via the control signal input means 41 (control
signal IF 11) (S601), the server control means 42 transmits an area
information request instruction for requesting information
representing areas in the data accumulation means 43 (data
accumulation section 13) where the data in the specified file are
recorded to the file system management means 44 (S602). Here, the
area information request instruction to be transmitted to the file
system management means 44 includes the occasional release
instruction.
[0124] Next, the server control means 42 receives area information
where the data in the specified file have been recorded transmitted
from the file system management means 44 according to the area
information request instruction (S603). After receiving the area
information about the specified file, the server control means 42
receives the reproduction instruction for actually starting the
data reproduction from outside (server controller 30) via the
control signal input means 41. Next, the server control means 42
controls the data output means 46 (data output IF 15) and the data
accumulation means 43, and reproduces the data in the specified
file from the data accumulation means 43 based on the area
information obtained from the file system management means 44 so as
to output the data as data D.sub.OUT from the data output means
46.
[0125] Next, when the data in the specified file in the data
accumulation means 43 are reproduced by a predetermined unit
(S605), the server control means 42 writes a value of the
reproduction position in the data recording area for the
on-reproducing file into the reproduction position transmission
means 47 (reproduction position storage area 23c of RAM 23) (S606).
Here, the data by a predetermined unit are data by 1 GOP unit, for
example, when the data are data compressed according to the MPEG
standard. Therefore, after the data are reproduced by 1 GOP unit,
the reproduction position is written in the reproduction position
transmission means 47.
[0126] Next, the server control means 42 judges as to whether or
not the reproduction halt instruction for halting the data
reproduction has been received from outside (server controller 30)
via the control signal input means 41 (S607). In the case where the
reproduction halt instruction has not been received (S607;N), the
server control means 42 judges as to whether or not the data in the
on-producing file have reached the End Of File (EOF) (S608). In the
case where the data in the on-reproducing file have not reached the
EOF (S608;N), the procedure returns to S605 so that the process is
repeated.
[0127] In addition, when the reproduction halt instruction has been
received (S607;Y) or the data in the on-reproducing file have
reached the EOF (S608;Y), the server control means 42 controls the
data accumulation means 43 so as to halt the operation for
reproducing the data (S609). Next, upon receiving the close
instruction from outside (server controller 30) via the control
signal input means 41 (S610), the server control means 42 transmits
the close instruction to the file system management means 44 (S611)
so as to end the process including the occasional release
instruction.
[0128] FIG. 12 is a flow chart for describing the operation
including the occasional release process in the file system
management means 44. As shown in this diagram, when the occasional
release process is accompanied, the file system management means 44
first receives the area information request instruction, which
includes the above-mentioned occasional release instruction and
requests the area information representing an area in the data
accumulation means 43 (data accumulation section 13) where the data
in a specified file have been recorded, from the server control
means 42 (S701). Then, after the process is waited for constant
time (S702), the file system management means 44 judges as to
whether or not the close instruction has been received from the
server control means 42 (S703). Here, the process is waited for
constant time at S702 in order to prevent useless process to be
executed by the CPU 21 composing the file system management means
44. When the process is waited for constant time, the CPU 21 can
execute another process. Here, in the case where the data
accumulated in the data accumulation means 43 are, for example, AV
data compressed according to the MPEG standard, the waiting time is
set for at least a value longer than the data reproduction time of
1 GOP. More specifically, the waiting time is set for about 1
second, for example.
[0129] In the case where the file system management means 44 has
not received the close instruction from the server control means 42
(S703;N), it reads in the value of the reproduction position of the
on-producing file written by the server control means 42 from the
reproduction position transmission means 47 (the reproduction
position storage area 23c of the RAM 23) (S704). The file system
management means 44 compares the read value of the reproduction
position with the management information owned by itself (the
management information storage area 23b of the RAM 23) in order to
judge as to whether or not the reproduction position of the
specified file has changed according to the occasional release
instruction (S705). Here, if the reproduction position of the file
has not changed (S705;N), the file system management means 44
repeats the process from S702.
[0130] In addition, if the reproduction position of the specified
file has changed according to the occasional release instruction
(S705;Y), the file system management means 44 releases the area in
the record entry where the data have been reproduced representing
the recording area corresponding to the change in the reproduction
position of the on-reproducing data in the management information
about the specified file (S706). After the released area is added
to the free space list (S707) and the management information has
been changed, the process from S702 is repeated.
[0131] In addition, upon receiving the close instruction from the
server control means 42 (S703;Y), the file system management means
44 reads a value of the reproduction position of the on-producing
file written by the server control means 42 from the reproduction
position transmission means 47 (S708). Then, the file system
management means 44 releases the reproduced area in the record
entry representing recording area corresponding to the reproduction
position of the on-producing data in the management information
about the specified file (S709). After the system management means
44 adds the released area to the free space list (S710) and updates
the management information, it ends the process including the
occasional release instruction. As mentioned above, the management
information is changed immediately according to the change in the
reproduction position of the on-producing file according to the
occasional release instruction, and the reproduced area is
released.
[0132] The following will particularly describe the sequence of
changing the management information accompanied by the occasional
release instruction, namely, the above-mentioned file entry, record
entry and free space list with reference to FIGS. 13 and 14. FIG.
13 is an explanatory diagram showing one example of a change in the
recording area in the data accumulation means 43 (data accumulation
section 13), when the occasional release instruction is given. FIG.
14 is an explanatory diagram showing a change in the management
information owned by the file system management means 44 to be
written according to the occasional release instruction in the
example shown in FIG. 13. Here, in FIGS. 13 and 14, for
convenience, address coincides with "minute".
[0133] As shown in FIG. 13A, for example, before reproduction of a
file under the occasional release instruction, in an address space
of the data accumulation means 43 whose total capacity is 100
minutes, the data in the file A are divided into three parts and
recorded in address 10 to 24 (15 minutes), address 30 to 54 (25
minutes) and address 60 to 79 (20 minutes). As this time, the space
areas are areas which are divided into four, namely, address 0 to 9
(10 minutes), address 25 to 29 (5 minutes), address 55 to 59 (5
minutes) and address 80 to 99 (20 minutes).
[0134] The area information shown in FIG. 13A is represented by the
management information shown in FIG. 14A. First, the information
corresponding to the areas where the file A is recorded is
represented by file entry and record entry. Namely, "A" is
described in the item of the file name of the file entry (FE), and
"10" and "15" are described respectively in the items of the head
position data and the size data in the record entry (RE-1) linked
with the file entry. Moreover, "30" and "25" are described
respectively in the items of the head position data and the size
data in the next record entry (RE-2) linked by the pointer of the
record entry (RE-1). Further, "60" and "20" are described
respectively in the items of the head position data and the size
data of the next record entry (RE-3) linked by the pointer of the
record entry (RE-2). Moreover, "EOF" representing end of data is
described in the item of the pointer to record entry next to the
record entry (RE-3).
[0135] In addition, the information corresponding to the space
areas is represented by free space list. Namely, "0" and "10" are
described respectively in the items of the head position data and
the size data in the first free space list (FSL-1). Moreover, "25"
and "5" are described respectively in the items of the head
position data and the size data (length) in the next free space
list (FSL-2) linked by the pointer of the free space list (FSL-1).
Further, "55" and "5" are described respectively in the items of
the head position data and the size data in the next free space
list (FSL-3) linked by the pointer of the free space list (FSL-2).
Furthermore, "80" and "20" are described respectively in the items
of the head position data and the size data in the next free space
list (FSL-4) linked by the pointer of the free space list (FSL-3).
Moreover, "EOL" representing end of list is described in the item
of the pointer to free space list next to the free space list
(FSL-4).
[0136] If the file A recorded as shown in FIG. 13A is reproduced by
.DELTA.T in time according to the file reproduction including the
occasional release instruction, data areas corresponding to
.DELTA.T are partially released.
[0137] FIG. 13B shows a state of the recording area when the data
are reproduced for 5 minutes, namely, the data are reproduced from
address 10 which is a head of the file A to the address 15 (5
minutes). The management information at this time is as shown in
FIG. 14B.
[0138] When the data area corresponding to the time .DELTA.T (5
minutes) is released according to the occasional release
instruction, the management information shown in FIG. 14A is
changed into the management information shown in FIG. 14B, namely,
the items of the head position data and the size data in the record
entry (RE-1) are respectively changed into "15" and "10". Moreover,
as for free space list, the item of the size in the free space list
(FSL-1) is changed from "10" into "15". As a result, it is found
that the size of the space area represented by the free space list
(FSL-1) is increased by time .DELTA.T (5 minutes).
[0139] The following will describe an example of the operation of
the data recording and reproducing apparatus 10 when the occasional
release instruction is executed during recording of plural files
with reference to FIGS. 15 through 17. Here, the description will
be given as to the case where the file A whose data amount is 40
minutes and the file B whose data amount is 30 minutes are recorded
in the data accumulation means 43 (data accumulation section 13)
whose data recording capacity is 60 minutes. Here, there considers
the case where all the recording areas in the data accumulation
means 43 are free, and data in the file A and the file B are
recorded in this order in the data accumulation means 43 in the
free state, and the recorded data are reproduced one by one.
[0140] FIG. 15 shows the operation of the data recording and
reproducing apparatus 10 when the file A and the file B are
recorded and reproduced in such a manner. FIG. 15A shows the
operation based on the input control signal S.sub.1 which is a
control signal for recording data, and FIG. 15B shows the operation
based on the output control signal S.sub.2 which is a control
signal for reproducing data. FIG. 16 shows a change in an area for
data recording in the data accumulation means 43 (data accumulation
section 13) during the operations shown in FIG. 15. FIG. 17 shows a
change in the management information owned by the file system
management means 44 during the operations shown in FIG. 15. Here,
in FIGS. 16 and 17, for convenience, address coincides with
"minute".
[0141] First, as shown in FIG. 15A, the data recording and
reproducing apparatus 10 receives the instruction (REC_OPEN "A"
command) for requesting preparation of recording of the file A as
the input control signal S.sub.1 from outside (server controller
30) (S801). At this time, the area for data recording in the data
accumulation means 43 is, as shown in FIG. 16A, free, and a
recordable data amount D.sub.f11 is 60 minutes in time. Moreover,
the management information owned by the file system management
means 44 at this time is represented as shown in FIG. 17A by using
the free space list (FSL) shown in FIG. 3C. Namely, "0" and "60"
are described respectively in the items of the head position data
and the size data, and "EOL" representing end of list is described
in the item of the pointer to the next free space list.
[0142] Upon receiving the REC_OPEN "A" command, the data recording
and reproducing apparatus 10 reserves the recording area for
recording the file A by 40 minutes as shown in FIG. 16B based on
the management information owned by the file system management
means 44. At this time, the file system management means 44 of the
data recording and reproducing apparatus 10 corrects (changes) the
management information to reserve the area for recording the file
A. The corrected management information is as shown in FIG. 17B.
When the management information is corrected in such a manner, an
amount D.sub.f12 of data, which can be recorded in the data
accumulation means 43 except for the data in the file A, becomes 20
minutes in time.
[0143] The information corresponding to the area for recording file
A in the management information shown in FIG. 17B is represented by
using file entry (FE) and record entry (RE). Namely, "A" is
described in the item of the file name in the file entry, and "0"
and "40" are described respectively in the items of the head
position data and the size data in the record entry linked with the
file entry. Moreover, "EOF" representing end of data is described
in the item of the pointer to the next record entry. Further, "40"
and "20" are described respectively in the items of the head
position data and the size data in the free space list representing
space areas, and "EOL" representing end of list is described in the
item of the pointer to the next free space list.
[0144] After the data recording and reproducing apparatus 10 has
received REC_OPEN "A" command, reserved the area for recording the
file A and corrected the management information, it receives from
outside (server controller 30) the recording instruction for
actually starting recording of the file A, and starts the recording
of the data in the file A in the reserved area of the data
accumulation means 43 (S802).
[0145] Next, upon receiving the recording halt instruction for
halting the recording of the file A from outside (server controller
30), the data recording and reproducing apparatus 10 halts the
operation for recording the file A (S803).
[0146] In addition, upon receiving the close instruction from
outside (server controller 30), the data recording and reproducing
apparatus 10 corrects (updates) the management information owned by
the file system management means 44 and closes the file (S804).
Here, in the file system management means 44, in the case where
there exists a difference between the management information first
created by the server control means 42 and a state of the recording
area where the data have been actually recorded, the difference is
adjusted as the process for closing file. Here, the file A is
recorded as shown in FIG. 16B according to the first created
management information.
[0147] When the file A is recorded as mentioned above, as shown in
FIG. 16B, the area occupied by the file A in the data accumulation
means 43 is 40 minutes, the recordable area where another data can
be recorded is 20 minutes. Therefore, at this time, the file B
whose data amount is 30 minutes cannot be recorded. Accordingly,
while the process for releasing the reproduced data portion at any
time is being executed, recording of the file B is started after
the process for reproducing the file A is executed for at least 10
minutes,.
[0148] As shown in FIG. 15B, in the case where the data recording
and reproducing apparatus 10 reproduces the file A, it receives the
instruction (PLAY_OPEN "A" command), which includes the occasional
release instruction and requests preparation of reproduction of the
file A, as the output control signal S.sub.2 from outside (server
controller 30) (S901).
[0149] Upon receiving the PLAY_OPEN "A" command including the
occasional release instruction, the data recording and reproducing
apparatus 10 retrieves the area information for reproducing the
file A based on the management information owned by the file system
management means 44. Upon receiving the reproduction instruction
for actually starting the reproduction of the file A from outside
(server controller 30), the data recording and reproducing
apparatus 10 starts the reproduction of the data in the file A from
the data accumulation means 43 based on the retrieved area
information (S902).
[0150] In addition, the data recording and reproducing apparatus 10
changes the management information whenever the data in the file A
are reproduced so that the reproduced data recording area occupied
by the reproduced data in the file A becomes an area where new data
can be recorded. When the operation for reproducing the file A
including the occasional release process is started, an amount
D.sub.f13 of data which can be recorded in the data accumulation
means 43 is increased at any time. For example, after the file A is
reproduced for 10 minutes, the recording area in the data
accumulation means 43 is as shown in FIG. 16C. Namely, the area of
address 0 to 9 is released, and data recordable area is created
newly. As a result, in addition to the space area of address 40 to
59, a recordable data amount D.sub.f14 becomes 30 minutes in time.
Therefore, at this time, the file B of 30 minutes can be
recorded.
[0151] FIG. 17C shows the management information which is created
after the file A is reproduced for 10 minutes. After the file A is
reproduced for 10 minutes as shown in this diagram, the management
information, in which the items of the head position data and the
size data in the record entry corresponding to the recording area
of the file A are changed respectively into "10" and "30", is
created.
[0152] Moreover, as the free space list representing space areas,
two lists, namely, FSL-1 and FSL-2 are created. "0" and "10" are
described respectively in the items of the head position data and
the size data in the free space list (FSL-1). Further, "40" and
"20" are described respectively in the items of the head position
data and the size data in the next free space list (FSL-2) linked
by the pointer of the free space list (FSL-1), and "EOL"
representing end of list is described in the item of the pointer to
the next free space list.
[0153] Next, upon receiving the reproduction halt instruction for
halting the reproduction of the file A from outside (server
controller 30), the data recording and reproducing apparatus 10
halts the operation for reproducing the file A including the
occasional release process (S903). Increase in an amount D.sub.f15
of data to be recordable in the data accumulation means 43 is
stopped by the halt of the reproduction operation.
[0154] In addition, upon receiving the close instruction from
outside (server controller 30), the data recording and reproducing
apparatus 10 closes the file A (S904), and ends the process for
reproducing the file A.
[0155] Meanwhile, the data recording and reproducing apparatus 10
starts the reproduction of the file A at S902, and reproduces the
file A for 10 minutes. After the amount D.sub.f13 of data to be
recordable in the data accumulation means 43 becomes 30 minutes
(=D.sub.f14) in time, the data recording and reproducing apparatus
10 receives the instruction for requesting preparation of recording
of the file B (REC_OPEN "B" command) as the input control signal
S.sub.1 from outside (server controller 30) (S805).
[0156] Upon receiving the REC_OPEN "B" command, the data recording
and reproducing apparatus 10 reserves an area for recording the
file B by 30 minutes as shown in FIG. 16D based on the management
information owned by the file system management means 44. At this
time, the data recording and reproducing apparatus 10 corrects
(changes) the management information according to the reservation
of the area for recording the file B. The corrected management
information is as shown in FIG. 17D. When the management
information is corrected in such a manner, an amount of data to be
recordable in the data accumulation means 43 which has been
increased anytime is temporarily decreased to 0 minute by the data
amount of the file B according to the operation for reproducing the
file A. Thereafter, the data amount is again increased anytime so
that a recordable data amount become D.sub.f15.
[0157] The management information shown in FIG. 17D is composed of
information corresponding to the areas for recording the file A and
the file B and the information about space areas. The information
corresponding to the area for recording the file A is represented
by the file entry (FE-1) and one record entry (RE). The record
entry (RE) of the file A is the same as that in FIG. 17C.
Meanwhile, the information corresponding to the area for recording
the file B is represented by the file entry (FE-2) and two record
entries (RE-1 and RE-2). "B" is described in the item of the file
name in the file entry (FE-2), and "0" and "10" are described
respectively in the items of the head position data and the size
data in the record entry (RE-1) linked with the file entry (FE-2).
Moreover, "40" and "20" are described respectively in the items of
the head position data and the size data (length) in the record
entry (RE-2) next to the record entry (RE-1), and "EOF"
representing end of data is described in the item of the pointer to
the record entry next to the record entry (RE-2). Further, "0" and
"0" are described respectively in the items of the head position
data and the size data in the free space list representing space
areas, and "EOL" representing end of list is described in the item
of the pointer to the next free space list.
[0158] The data recording and reproducing apparatus 10 receives the
REC_OPEN "B" command, and reserves the area for recording the file
B and corrects the management information. Thereafter, upon
receiving from outside (server controller 30) the recording
instruction for actually starting the recording of the file B, the
data recording and reproducing apparatus 10 starts the recording of
the data in the file B in the reserved area of the data
accumulation means 43 (S806).
[0159] Next, upon receiving the recording halt instruction for
halting the recording of the file B from outside (server controller
30), the data recording and reproducing apparatus 10 halts the
operation for recording the file B (S807).
[0160] In addition, upon receiving the close instruction from
outside (server controller 30), the data recording and reproducing
apparatus 10 corrects (updates) the management information about
the file B owned by the file system management means 44 so as to
close the file B (S809), and ends the process for recording the
file B.
[0161] FIGS. 16E and 17E show the recording areas in the data
accumulation means 43 and the management information owned by the
file system management means 44 after the reproduction of the file
A and the recording of the file B are ended. As shown in FIG. 16E,
when the reproduction of the file A and the recording of the file B
are ended, the file B is recorded in the area of address 0 to 9 and
the area of address 40 to 59 in the data accumulation means 43, and
the area of address 10 to 39 becomes free. In the management
information at this time, as shown in FIG. 17E, the file entry
(RE-1) and one record entry (RE) corresponding to the recording
area of the file A are deleted from the management information in
FIG. 17D. Moreover, the items of the head position data and the
size data in the free space list representing space areas are
changed into "10" and "30" respectively.
[0162] Since the area where the file A has been reproduced is
released anytime while the file A is reproduced in the
above-mentioned manner, even before the whole file A is reproduced
and deleted, the file B can be recorded.
[0163] FIGS. 18A and 18B show an explanatory diagram for comparing
changes in the recordable area in the operation shown in FIG. 7 and
the operation shown in FIG. 15. Namely, FIG. 18A shows a change in
the recordable area according to the I/O control signals which do
not include the occasional release instruction, and FIG. 18B shows
a change in the recordable area according to the I/O control
signals which include the occasional release instruction. In FIGS.
18A and 18B, the vertical axis represents the recordable area and
the horizontal axis represents time.
[0164] As shown in FIG. 18A, at the time of the operation in
absence of the occasional release instruction, when the recording
of the file A is started (t.sub.1), the recordable area becomes 20
minutes in time. Next, after the recording of the file A is ended,
when the whole file A is reproduced and deleted (t.sub.2), the
recordable area becomes 60 minutes. When the recording of the file
B is started (t.sub.3), the recordable area becomes 30 minutes.
[0165] Meanwhile, as shown in FIG. 18B, in the operation under the
occasional release instruction, in the case where the operation
shown in FIG. 15, including the occasional release process in file
A, the recordable area becomes 20 minutes in time when the
recording of the file A is started (t.sub.11=t.sub.1). Next, after
the recording of the file A is ended, when the reproduction of the
file A including the occasional release process is started
(t.sub.12), the recordable area is increased anytime. Ten minutes
after starting reproduction of the file A, the recordable area
becomes 30 minutes. At this point of time, if the recording of the
file B is started (t_), then the recordable area becomes 0 minute.
However, while the occasional release process for the file A is
being continued, the recordable area is increased anytime. The
increase in the recordable area is stopped simultaneously with the
end of the occasional release process for the file A (t.sub.14). In
the operation shown in FIG. 15 including the occasional release
process for the file A, it is found that the recordable area in the
data accumulation means 43 (data accumulation section 13) is used
efficiently. Moreover, as is clear from comparison of the starting
times of the recording of the file B t.sub.3 and t.sub.13 in FIG.
18, in the operation including the occasional release process for
the file A, the starting time t.sub.13 of the recording of the file
B is earlier than the time t.sub.3. This is because the file B
becomes recordable at the time when the reproduction process for
the file A including the occasional release process is executed for
10 minutes, even if reproduction of the whole file A is not
completed. As is clear from this, the total data recording time is
shortened by generating the occasional release instruction.
[0166] As described above, in the data recording and reproducing
apparatus 10 according to the present embodiment, management
information is changed anytime according to the occasional release
instruction from outside (server controller 30) added to the
PLAY_OPEN command for requesting preparation of reproduction of
data so that the area where the reproduced data of the data in an
arbitrary file have been recorded may become recordable while the
data are being reproduced. For this reason, before the reproduction
of the on-reproducing file is completed, new data can be recorded
in the area occupied by the reproduced data, and thus the area for
data recording in the data accumulation means 43 (data accumulation
section 13) can be utilized efficiently. As a result, for example
when plural data are recorded, a trouble such that the data cannot
be recorded because of less recordable area can be decreased.
Moreover, the data recording time required for recording plural
data can be shortened.
[0167] The present invention is not limited to the aforementioned
embodiment, and can be variously modified. For example, the present
invention is not limited to using as an AV server which treats with
audio/visual data, and thus can be applied also to an apparatus to
be used for recording and reproducing the other kinds of data.
[0168] In addition, the above embodiment described the case where
the reproduction position transmission means 47 is provided, but
the occasional release process may be executed without providing
the reproduction position transmission means 47. In this case,
transmission of the reproduction position under the occasional
release process is performed as a command from the server control
means 42 directly to the file system management means 44 in real
time. As a result, the process for releasing reproduced data
recording area can be executed in real time.
[0169] In addition, the occasional release process may not be
executed according to the occasional release instruction from the
server controller 30, but may be always executed for all the files
to be reproduced.
[0170] The following will describe second embodiment. Here, in the
following description, the same parts as the components in the
first embodiment are noted by the same reference numerals, and the
description thereof is omitted.
[0171] The above-mentioned first embodiment described the example
that when data are reproduced from the data recording and
reproducing apparatus 10, the reproduced data are released anytime
from the recording area so that the storage efficiency is improved.
However, the present embodiment will describe an example in detail
that when data are reproduced, a recording area is released
according to an instruction from outside.
[0172] In the present embodiment, the server controller 30 in FIG.
1 transmits an instruction, which releases a data recording area so
that an area occupied by reproduced data of an area in the data
accumulation section 13 occupied by the on-reproducing data is
changed into an area where new data can be recorded, (hereinafter,
such instruction is referred to as a release instruction) as the
input control signal S.sub.1.
[0173] Upon receiving the release instruction, the control section
12 of the data recording and reproducing apparatus 10 corrects
management information stored in the management information
recording area 23b so that the area where the data have been
reproduced of the on-reproducing data area becomes a recordable
area, and releases the recording area so that new data can be
recorded.
[0174] The following will describe a process for transmitting the
release instruction for releasing a data area by the server
controller 30 to the data recording and reproducing apparatus 10,
and the description will be detailed as to the process to be
executed by the data recording and reproducing apparatus 10 which
has received the release instruction or the like, on the server
controller 30.
[0175] FIG. 19 is a flow chart showing the process for transmitting
the release instruction to the data recording and reproducing
apparatus 10. More specifically, when data are being reproduced in
the data accumulation section 13 of the data recording and
reproducing apparatus 10, before the REC_OPEN command which is a
file recording preparation instruction is transmitted, the release
instruction is transmitted so that the area is released. The
description will be given below following the sequence.
[0176] First, when this process is started, a judgment is made as
to whether or not an amount of data in a file to be recorded
(recording time) exceeds a space area in the data recording and
reproducing apparatus 10 (S191). When the data amount does not
exceed the space area in the data recording and reproducing
apparatus 10 (S191;N), the data accumulation section 13 has
capacity where data can be recorded. Therefore, the server
controller 30 transmits the REC_OPEN command which is the file
recording preparation instruction directly to the data recording
and reproducing apparatus 10 (S197).
[0177] Meanwhile, when the data amount exceeds the space area in
the data recording and reproducing apparatus 10 (S191;Y), the
server controller 30 judges as to whether or not the file
accumulated in the data accumulation means 43 (data accumulation
section 13) is being reproduced in the data recording and
reproducing apparatus 10 (S192). When the file is not being
reproduced in the data recording and reproducing apparatus 10
(S192;N), the server controller 30 judges that the recording
request is unsuccessful (S198), and ends the process.
[0178] In addition, when the data recording and reproducing
apparatus 10 is reproducing the file (S192;Y), the server
controller 30 subtracts a space area in the data accumulation means
43 and the time required for reproducing the on-reproducing file
from an amount of the data in the file to be recorded (recording
time) (S193). Next, the server controller 30 judges as to whether
or not the obtained value T exceeds 0 (S194). Namely, the server
controller 30 judges as to whether or not the recording area of the
file to be recorded is reserved in the data accumulation means 43.
Here, all the recording time, the space area and the time required
for reproducing the on-reproducing file are grasped by the server
controller 30.
[0179] When the calculated value T does not exceed 0 (S194;N),
namely the recording area of the file to be recorded has been
already reserved in the data accumulation means 43, the server
controller 30 transmits the release instruction to the data
recording and reproducing apparatus 10 (S196) so as to immediately
release the recording area of the on-producing data. Then, the
server controller 30 transmits the REC_OPEN command for preparing
the recording of the file to the data recording and reproducing
apparatus 10 (S197).
[0180] Meanwhile, when the calculated value T exceeds 0 (S194;Y),
the area for the file to be recorded is not reserved. Therefore,
the server controller 30 waits until the time corresponding to the
calculated value T passes (S195), and generates the aforementioned
release instruction (S196) so as to transmit the REC_OPEN command
to the data recording and reproducing apparatus 10 (S197). As a
result, this process is ended.
[0181] The following will describe the operation to be performed by
the data recording and reproducing apparatus 10 upon receiving the
release instruction with reference to FIG. 20.
[0182] As shown in FIG. 20, upon receiving the release instruction
from outside (server controller 30) (S711), the data recording
reproducing apparatus 10 judges as to whether or not a file
specified by the release instruction is being reproduced in the
data accumulation means 43 (data accumulation section 13) (S712).
Here, when the specified is not being reproduced (S712;N), the data
recording and reproducing apparatus 10 ends the process by the
release instruction.
[0183] In addition, when the specified file is being reproduced
(S712;Y), the data recording and reproducing apparatus 10 locks
(inhibits changing according to the other processes) the management
information so that the management information is not changed
according to the other processes during on-reproduction of the
process according to the release instruction (S713).
[0184] Next, the file system management means 44 of the data
recording and reproducing apparatus 10 corrects (changes) the
management information according to the release instruction. Here,
the on-correcting management information is not cataloged in the
management information storage area 23b of the RAM 23 during
correction of the management information but held in the work area
23a of the RAM 23, and after the correction is completed, the
corrected management information is cataloged in the management
information storage area 23b. The data recording and reproducing
apparatus 10 first releases the record entry where data have been
reproduced in the whole area in the management information about
the specified file as the process for correcting management
information according to the release instruction (S714). Then, the
released area is added to the free space list (S715). Here, the
record entry where data have been reproduced in the whole area is
at least one record entry corresponding to divided areas where
reproduction has been executed completely in plural divided areas
when the specified file is divided into plural parts so as to be
recorded in plural areas, for example.
[0185] Next, the data recording and reproducing apparatus 10
releases areas where the reproduction has been executed in the
record entry representing the recording areas for on-reproducing
data in the management information about the specified file (S716).
Then, the data recording and reproducing apparatus 10 adds the
released areas to the free space list (S717). Here, the
reproduction area in the record entry representing recording area
for on-reproducing data is an area corresponding to a portion where
the data have been reproduced in the area represented by the record
entry in the case where the data recorded in the area represented
by a certain record entry are being reproduced. Moreover, a
judgment is made in the following manner, for example, as to how
long the area, where the reproduction has been executed, occupies
the recording area represented by the record entry. Namely, the CPU
21 of the server control means 42 counts reproduction time in an
internal counter so as to judge that the area, where the data have
been recorded, corresponding to the counted time is the area where
the data have been reproduced.
[0186] When the area where the data have been recorded is released
in the above manner, the position of the pointer to the record
entry of the file entry about the specified file is changed. For
this reason, the data recording and reproducing apparatus 10
changes the connection of the pointer into the changed record entry
(S718). When the processes at S714 through S718 are executed as
mentioned above, the management information corrected according to
the release instruction is created.
[0187] Next, the data recording and reproducing apparatus 10
rewrites and updates the management information owned by the file
system management means 44 into the corrected management
information (S719) and releases the lock of the management
information (S720) to end the process according to the release
instruction.
[0188] The following will describe particularly the procedure of
creating the management information created according to the
release instruction with reference to FIGS. 21 and 22. FIG. 21
shows one example of a change in the recording area in the data
accumulation means 43 (data accumulation section 13) according to
the release instruction. FIG. 22 shows a change in the management
information owned by the file system management means 44 to be
written according to the release instruction in the example shown
in FIG. 21. Here, in FIGS. 21 and 22, for convenience, address
coincides with "minute".
[0189] As shown in FIG. 21A, for example, before execution of the
release instruction, in address space in the data accumulation
means 43 whose total capacity is 100 minutes, the data in the file
A are recorded into three areas, i.e., address 10 to 24 (15
minutes), address 30 to 54 (25 minutes) and address 60 to 79 (20
minutes). At this time, space areas are divided into four area
portions, i.e., address 0 to 9 (10 minutes), address 25 to 29 (5
minutes), address 55 to 59 (5 minutes) and address 80 to 99 (20
minutes).
[0190] The area information shown in FIG. 21A is represented by the
management information shown in FIG. 22A. First the information
corresponding to an area where the file A has been recorded is
represented by file entry and record entry. Namely, "A" is
described in the item of the file name in the file entry (FE), and
"10" and "15" are described respectively in the items of the head
position data and the size data in the record entry (RE-1) linked
with the file entry. Moreover, "30" and "25" are described
respectively in the items of the head position data and the size
data in the next record entry (RE-2) linked by the pointer of the
record entry (RE-1). Further, "60" and "20" are described
respectively in the items of the head position data and the size
data in the next record entry (RE-3) linked by the pointer of the
record entry (RE-2). Moreover, "EOF" representing end of data is
described in the item of the pointer to record entry next to the
record entry (RE-3).
[0191] In addition, the information corresponding to space areas is
represented by free space list. Namely, "0" and "10" are described
respectively in the items of the head position data and the size
data in the first free space list (FSL-1). Moreover, "25" and "5"
are described respectively in the items of the head position data
and the size data in the next free space list (FSL-2) linked by the
pointer of the free space list (FSL-1). Further, "55" and "5" are
described respectively in the items of the head position data and
the size data in the next free space list (FSL-3) linked by the
pointer of the free space list (FSL-2). Furthermore, "80" and "20"
are described respectively in the items of the head position data
and the size data in the next free space list (FSL-4) linked by the
pointer of the free space list (FSL-3). Moreover, "EOL"
representing end of list is described in the item of the pointer to
free space list next to the free space list (FSL-4).
[0192] In the case where just when the file A recorded as shown in
FIG. 21A is reproduced for 25 minutes, the release instruction is
executed on the file A, the whole area represented by the record
entry (RE-1) and partial area of the first 10 minutes in the area
represented by the recorded entry (RE-2) (also shown in FIG. 22A)
are released.
[0193] First, when the whole area represented by the record entry
(RE-1) shown in FIG. 22A is released, the state of an area is as
shown in FIG. 21B, and the management information at this time is
in a state shown in FIG. 22B. This state corresponds to the case
where the processes at S714 and S715 in FIG. 20 are executed.
[0194] As for the management information shown in FIG. 22B, the
record entry (RE-1) is deleted by releasing the record entry (RE1),
and the record entry linked with the file entry is changed into the
record entry (RE-2). Moreover, as for the free space list, the item
of the size data in the free space list (FSL-1) is changed from
"10" into "30", and the free space list (FSL-2) is deleted.
Moreover, according to the deletion of the free space list (FSL-2),
the free space list (FSL-1) is linked with the free space list
(FSL-3).
[0195] Further, after the whole area represented by the record
entry (RE-1) is released, an area for 10 minutes of the area
represented by the record entry (RE-2) is released. As a result,
the area is in a state shown in FIG. 21C, and the management
information at this time is in a state shown in FIG. 22C. This
state corresponds to the case where the processes at S716 and S717
in FIG. 20 are executed.
[0196] As for the management information shown in FIG. 22C, from
the state of the management information shown in FIG. 22B, the
items of the head position data and the size data in the record
entry (RE-2) are changed respectively into "40" and "15" by
partially releasing the record entry (RE-2). Moreover, as for the
free space list, the item of the size data in the free space list
(FSL-1) is changed into "40".
[0197] The following will describe an example of the operation of
the data recording and reproducing apparatus 10 in the case where
the release instruction is executed according to recording of
plural data. Here, the description will be given as to the case
where the file A whose data amount is 40 minutes and the file B
whose data amount is 30 minutes are recorded in the data
accumulation means 43 (data accumulation section 13) whose data
recording capacity is 60 minutes. Moreover, there considers the
case where whole area for data recording in the data accumulation
means 43 is first free, and data in the file A and the file B are
recorded in this order in the data accumulation means 43 in the
free state, and the recorded data are reproduced one by one.
[0198] FIG. 23 is an explanatory diagram showing the operation of
the data recording and reproducing apparatus 10 in the case where
the file A and the file B are recorded and reproduced in the above
manner. FIG. 23A shows the operation based on the input control
signal S.sub.1, and FIG. 23B shows the operation based on the
output control signal S.sub.2. FIG. 24 shows a change in an area
for data recording in the data accumulation means 43 (data
accumulation section 13) according to the operations shown in FIG.
23. FIG. 25 shows a change in the management information owned by
the file system management means 44 according to the operations
shown in FIG. 23. Here, in FIGS. 24 and 25, for convenience,
address coincides with "minute".
[0199] As shown in FIG. 23A, the data recording and reproducing
apparatus 10 receives the instruction for requesting preparation of
recording of the file A (REC_OPEN "A" command) as the input control
signal S.sub.1 from outside (server controller 30) (S911). At this
time, an area for data recording in the data accumulation means 43
is, as shown in FIG. 24A, free, and a recordable data amount
D.sub.f11 is 60 minutes in time. Moreover, the management
information owned by the file system management means 44 at this
time is represented as shown in FIG. 25A by the free space list
(FSL) shown in FIG. 3C. Namely, "0" and "60" are described
respectively in the items of the head position data and the size
data, and "EOL" representing end of list is described in the item
of the pointer to the next free space list.
[0200] Upon receiving the REC_OPEN "A" command, the data recording
and reproducing apparatus 10 reserves an area for recording the
file A by 40 minutes as shown in FIG. 24B, for example, based on
the management information owned by the file system management
means 44. At this time, the file system management means 44 of the
data recording and reproducing apparatus 10 corrects (changes) the
management information according to the reservation of the area for
recording the file A. The corrected management information is as
shown in FIG. 25B. When the management information is corrected in
such a manner, an amount D.sub.f12 of data other than the data in
the file A which can be recorded in the data accumulation means 43
becomes 20 minutes in time.
[0201] The information in the management information shown in FIG.
25B corresponding to the area for recording the file A is
represented by using file entry (FE) and record entry (RE). Namely,
"A" is described in the item of the file name in the file entry,
and "0" and "40" are described respectively in the items of the
head position data and the size data in the record entry linked
with the file entry. Moreover, "EOF" representing end of data is
described in the item of the pointer to the next record entry.
Moreover, "40" and "20" are described respectively in the items of
the head position data and the size data in the free space list
representing space areas, and "EOL" representing end of list is
described in the item of the pointer to the next free space
list.
[0202] The data recording and reproducing apparatus 10 receives
REC_OPEN "A" command, reserves the area for recording the file A
and corrects the management information. Thereafter, upon receiving
the recording instruction from outside (server controller 30) for
actually starting the recording of the file A, the data recording
and reproducing apparatus 10 starts to record the data in the file
A in the reserved area of the data accumulation means 43
(S912).
[0203] Next, upon receiving the recording halt instruction from
outside (server controller 30) for halting the recording of the
file A, the data recording and reproducing apparatus 10 halts the
recording of the file A (S913).
[0204] In addition, upon receiving the close instruction from
outside (server controller 30), the data recording and reproducing
apparatus 10 corrects (updates) the management information owned by
the file system management means 44 and closes the file (S914).
Here, in the file system management means 44, if there exists a
difference between the management information first created by the
server control means 42 and the area where the data have been
actually recorded, the difference is adjusted as the process for
closing the file. Here, the file A is recorded as shown in FIG. 24B
according to the management information first created.
[0205] When the file A is recorded in the above-mentioned manner,
as shown in FIG. 24B, the area where the data have been recorded
occupied by the file A in the data accumulation means 43 is 40
minutes, and the recordable area where another data can be recorded
is 20 minutes. Therefore, the file B whose data amount is 30
minutes cannot be recorded at this time. Accordingly, next, after
the file A is reproduced for at least 10 minutes, the reproduced
file A is partially released.
[0206] As shown in FIG. 23B, when the data recording and
reproducing apparatus 10 reproduces the file A, it receives the
instruction for requesting preparation of reproduction of the file
A (PLAY_OPEN "A" command) as the output control signal S.sub.2 from
outside (server controller 30) (S920).
[0207] Upon receiving the PLAY_OPEN "A" command, the data recording
and reproducing apparatus 10 retrieves the area information for
reproducing the file A based on the management information owned by
the file system management means 44. Then, upon receiving the
reproduction instruction for actually starting reproduction of the
file A from outside (server controller 30), the data recording and
reproducing apparatus 10 starts the reproduction of the data in the
file A from the data accumulation means 43 based on the retrieved
area information (S921).
[0208] Next, upon receiving the reproduction halt instruction for
halting the reproduction of the file A from outside (server
controller 30), the data recording and reproducing apparatus 10
halts the reproduction of the file A (S922).
[0209] In addition, upon receiving the close instruction from
outside (server controller 30), the data recording and reproducing
apparatus 10 closes the file (S923), and ends the reproduction of
the file A.
[0210] Meanwhile, the data recording and reproducing apparatus 10
starts the reproduction of the file A at S921, and reproduces the
file A for 10 minutes. Thereafter, as shown in FIG. 23B, upon
receiving the release instruction of the file A from outside
(server controller 30) (S915), the data recording and reproducing
apparatus 10 releases the area where the file A has been reproduced
according to the release instruction. At this time, the area for
data recording in the data accumulation means 43 is as shown in
FIG. 24C. Namely, the area of address 0 to 9 is released, and an
area where new data can be recorded is created. As a result, in
addition to the area of address 40 to 59 which is free before
executing the release instruction, a recordable data amount
D.sub.f13 becomes 30 minutes in time. Therefore, the file B by 30
minutes can be recorded at this time.
[0211] In addition, the file system management means 44 of the data
recording and reproducing apparatus 10 corrects (changes) the
management information according to the execution of the release
instruction. The corrected management information is represented as
shown in FIG. 25C. Namely, as for the management information shown
in FIG. 25B, the items of the head position data and the size data
in the record entry corresponding to the area for recording the
file A are changed respectively into "10" and "30" so that the
management information shown in FIG. 25C is created. Moreover, two
lists FSL-1 and FSL-2 are created as free space list representing
space areas. "0" and "10" are described respectively in the items
of the head position data and the size data in the free space list
(FSL-1). Further, "40" and "20" are described respectively in the
items of the head position data and the size data in the next free
space list (FSL-2) linked by the pointer of the free space list
(FSL-1), and "EOL" representing end of list is described in the
item of the pointer to the next free space list.
[0212] Next, the data recording and reproducing apparatus 10
receives the instruction for requesting preparation of recording of
the file B (REC_OPEN "B" command) as the input control signal
S.sub.1 from outside (server controller 30) (S916).
[0213] Upon receiving the REC_OPEN "B" command, the data recording
and reproducing apparatus 10 reserves an area for recording the
file B by 30 minutes as shown in FIG. 24D based on the management
information owned by the file system management means 44. At this
time, the file system management means 44 of the data recording and
reproducing apparatus 10 corrects (changes) the management
information according to the reservation of the area for recording
the file B. The corrected management information is as shown in
FIG. 25D. When the management information is corrected, an amount
D.sub.f14 of data other than the data in the file B, which can be
recorded in the data accumulation means 43, becomes 0 minute in
time.
[0214] The management information shown in FIG. 25D is composed of
the information corresponding to the areas for recording the file A
and the file B and the information about space areas. The
information corresponding to the area for recording the file A is
represented by using file entry (FE-1) and one record entry (RE).
The record entry (RE) of the file A is the same as that in FIG.
25C. Meanwhile, the information corresponding to the area for
recording the file B is represented by using the file entry (FE-2)
and two record entries (RE-1 and RE-2). "B" is described in the
item of the file name in the file entry (FE-2), and "0" and "10"
are described respectively in the items of the head position data
and the size data in the record entry (RE-1) linked with the file
entry (FE-2). Moreover, "40" and "20" are described respectively in
the items of the head position data and the size data in record
entry (RE-2) next to the record entry (RE-1), and "EOF"
representing end of data is described in the item of the pointer of
record entry next to the record entry (RE-2). Further, "0" and "0"
are described respectively in the items of the head position data
and the size data in free space list representing space areas, and
"EOL" representing end of list is described in the item of the
pointer to the next free space list.
[0215] The data recording and reproducing apparatus 10 receives the
REC_OPEN "B" command, and reserves the area for recording the file
B and corrects the management information. Thereafter, upon
receiving the recording instruction from outside (server controller
30) for actually starting recording of the file B, the data
recording and reproducing apparatus 10 starts the recording of the
data in the file B into the revered area of the data accumulation
means 43 (S917).
[0216] Next, upon receiving the recording halt instruction from
outside (server controller 30) for halting the recording of the
file B, the data recording and reproducing apparatus 10 halts the
recording of the file B (S918).
[0217] In addition, the file system management means 44 of the data
recording and reproducing apparatus 10 receives the close
instruction from outside (server controller 30), the file system
management means 44 corrects (updates) the management information
and closes the file (S919), and ends the recording of the file
B.
[0218] As mentioned above, when the release instruction is received
at the time when the file A is reproduced for 10 minutes, the area
where the file A has been released is released so as to be changed
into a recordable area, and thus even before the whole file A is
reproduced and deleted, the file B can be recorded.
[0219] FIGS. 26A and 26B show an explanatory diagram where changes
in recordable areas between the operation shown in FIG. 7 and the
operation shown in FIG. 23 are compared. Namely, FIG. 26A shows a
change in the recordable area when the release instruction is not
received, and FIG. 26B shows a change in the recordable area when
the release instruction is received. In FIGS. 26A and 26B, the
vertical axis represents the recordable area, and the horizontal
axis represents time.
[0220] As shown in FIG. 26A, when the recording of the file A is
started (t.sub.1), the recordable area becomes 20 minutes in time.
Next, when after the recording of the file A is ended, the file A
is reproduced completely and deleted (t.sub.2), the recordable area
becomes 60 minutes. When the recording of the file B is started
(t.sub.3), the recordable area becomes 30 minutes.
[0221] Meanwhile, as shown in FIG. 26B, when the recording of the
file A is started (t.sub.11=t.sub.1), the recordable area becomes
20 minutes in time. Next, when after the recording of the file A is
ended, the file A is reproduced for 10 minutes and the data in the
file A of 10 minutes are released (t.sub.12), the recordable area
becomes 30 minutes. Then, when the recording of the file B is
started (t.sub.13 ), the recordable area becomes 0 minute.
[0222] In the operation shown in FIG. 23 under the release
instruction, it is found that the area for data recording in the
data accumulation means 43 (data accumulation section 13) is used
efficiently. Moreover, in FIG. 26, as is clear from comparing the
starting times t.sub.3 and t.sub.13 when the file B is recorded, in
the operation under the release instruction, the time t.sub.13 when
the recording of the file B is started is earlier than the time
t.sub.3. This is because in the operation shown in FIG. 23, after
the release instruction is generated, the file B can be recorded
without waiting the complete reproduction of the file A. As is
clear from this, the total time required for recording data is
shortened by generating the release instruction.
[0223] As mentioned above, in the data recording and reproducing
apparatus 10 according to the present embodiment, the management
information is changed so that while the data in an arbitrary file
is being reproduced, the area where the reproduced data of the data
in the file are recorded becomes a recordable area according to the
release instruction from outside (server controller 30). For this
reason, before the on-reproducing file is reproduced completely,
new data can be recorded in an area occupied by the on-reproduced
data, and the area for data recording in the data accumulation
means 43 (data accumulation section 13) can be utilized
efficiently. As a result, in the case where plural data are
recorded, for example, a problem that data cannot be recorded due
to less recordable area can be decreased. Moreover, the time
required for recording plural data can be shortened.
[0224] As mentioned above, the present invention outputs the
reproduction position information representing a reproduction
position of data in a recording medium, and the occasional release
instruction for executing the occasional release process so that
while the data are being reproduced from a recording medium, new
data can be recorded in the area in the recording medium where the
reproduced data are recorded. Moreover, the present invention
changes management information representing an area in the
recording medium where the data have been recorded and a recordable
area where data can be recorded, and manages management information
so that the occasional release process is executed on the recording
medium. As a result, new data can be recorded in the area occupied
by the reproduced data anytime before the on-reproducing file is
reproduced completely. Therefore, the present invention has the
effect that an area in the data accumulation means for data
recording can be utilized efficiently.
[0225] In addition, when data is being reproduced from a recording
medium, the present invention inputs the release instruction for
executing the release process so that new data can be recorded in
an area in the recording medium where the reproduced data are
recorded, and changes management information representing an area
in the recording medium where the data have been recorded and
recordable areas data can be recorded based on the inputted release
instruction. Moreover, the present invention manages the management
information so that the release process is executed on the
recording medium. As a result, before on-reproducing file is
reproduced completely, new data can be recorded in an area occupied
by the reproduced data. Therefore, the present invention has the
effect that an area in the data accumulation means for data
recording can be utilized efficiently.
[0226] Based on the description as above, obviously many
modifications and variations of the present invention are possible.
Accordingly, the present invention may also be practiced in
embodiments other than those described above, within the equivalent
scope of the following claims.
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