U.S. patent application number 12/732644 was filed with the patent office on 2011-03-31 for av data reproducing device, method for reproducing av data, and recording medium for the same.
This patent application is currently assigned to SHARP KABUSHIKI KAISHA. Invention is credited to Yuri IWANO, Jiro KIYAMA, Takayoshi YAMAGUCHI.
Application Number | 20110075986 12/732644 |
Document ID | / |
Family ID | 32109476 |
Filed Date | 2011-03-31 |
United States Patent
Application |
20110075986 |
Kind Code |
A1 |
KIYAMA; Jiro ; et
al. |
March 31, 2011 |
AV DATA REPRODUCING DEVICE, METHOD FOR REPRODUCING AV DATA, AND
RECORDING MEDIUM FOR THE SAME
Abstract
An original stream file and an after-recording data file are
managed as different files. In the original stream file, data is
made up of sets of partial data (CU) divided in accordance with a
predetermined interval. Likewise, in the after-recording data file,
data is made up of sets of partial data (CA) divided in accordance
with a predetermined interval. These sets of data are recorded onto
a disc such that the after-recorded data (CA) is recorded in a
region adjacent to a relevant original stream (CU). This allows
reproduction and real-time after-recording with the use of a
general MPEG-2 PS/TS decoder. Moreover, this allows realization of
data recording that causes less interruption of reproduction when
non-destructive editing is carried out with respect to an
after-recorded result.
Inventors: |
KIYAMA; Jiro; (Chiba,
JP) ; IWANO; Yuri; (Chiba, JP) ; YAMAGUCHI;
Takayoshi; (Chiba, JP) |
Assignee: |
SHARP KABUSHIKI KAISHA
Osaka
JP
|
Family ID: |
32109476 |
Appl. No.: |
12/732644 |
Filed: |
March 26, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10531534 |
Apr 15, 2005 |
7817897 |
|
|
PCT/JP03/13209 |
Oct 15, 2003 |
|
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12732644 |
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Current U.S.
Class: |
386/239 ;
369/47.1; 386/E9.011; G9B/27.05; G9B/5.033 |
Current CPC
Class: |
H04N 5/85 20130101; G11B
2220/2562 20130101; H04N 9/8042 20130101; G11B 27/3027 20130101;
G11B 27/329 20130101; H04N 9/8063 20130101; G11B 2220/2575
20130101; G11B 27/034 20130101; G11B 2220/216 20130101; G11B 27/036
20130101; G11B 20/10 20130101 |
Class at
Publication: |
386/239 ;
369/47.1; 386/E09.011; G9B/5.033; G9B/27.05 |
International
Class: |
H04N 9/80 20060101
H04N009/80; G11B 5/09 20060101 G11B005/09 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 17, 2002 |
JP |
2002-303648 |
Jan 10, 2003 |
JP |
5058/2003 |
Claims
1-14. (canceled)
15. An AV data reproducing device for reproducing AV data stored on
a recording medium storing at least AV data and associated data
which is associated with the AV data, the AV data and the
associated data constituting a scene to be reproduced at the same
time, wherein: the AV data and the associated data are so stored on
the recording medium that the AV data is divided into partial AV
data in accordance with a predetermined rule, the associated data
is divided into partial associated data in accordance with a
predetermined rule, and the partial AV data and the partial
associated data, which are to be reproduced at the same time, are
disposed alternately; the recording medium further storing: file
system management information for managing information for handling
as different files the AV data and the associated data; the file
system management information includes: position information of the
partial AV data in an order of reproducing the partial AV data, and
position information of the partial associated data in an order of
reproducing the partial associated data; the device comprising: a
section for acquiring the file system management information from
the recording medium.
16. The AV data reproducing device as set forth in claim 15,
wherein each of the AV data and the associated data is multiplexed
in accordance with a predetermined multiplexing rule.
17. An AV data reproducing method for reproducing AV data stored on
a recording medium storing at least AV data and associated data
which is associated with the AV data, the AV data and the
associated data constituting a scene to be reproduced at the same
time, wherein: the AV data and the associated data are so stored on
the recording medium that the AV data is divided into partial AV
data in accordance with a predetermined rule, the associated data
is divided into partial associated data in accordance with a
predetermined rule, and the partial AV data and the partial
associated data, which are to be reproduced at the same time, are
disposed alternately; the recording medium further storing: file
system management information for managing information for handling
as different files the AV data and the associated data; the file
system management information includes: position information of the
partial AV data in an order of reproducing the partial AV data, and
position information of the partial associated data in an order of
reproducing the partial associated data; the method comprising: a
step of acquiring the file system management information from the
recording medium.
18. A non-transitory computer readable recording medium for storing
a program for causing a computer to reproduce AV data stored on a
recording medium storing at least AV data and associated data which
is associated with the AV data, the AV data and the associated data
constituting a scene to be reproduced at the same time, wherein:
the AV data and the associated data are so stored on the recording
medium that the AV data is divided into partial AV data in
accordance with a predetermined rule, the associated data is
divided into partial associated data in accordance with a
predetermined rule, and the partial AV data and the partial
associated data, which are to be reproduced at the same time, are
disposed alternately; the recording medium further storing: file
system management information for managing information for handling
as different files the AV data and the associated data; the file
system management information includes: position information of the
partial AV data in an order of reproducing the partial AV data, and
position information of the partial associated data in an order of
reproducing the partial associated data; the program causing the
computer to perform: a step of acquiring the file system management
information from the recording medium.
19. A non-transitory recording medium for use by the AV data
reproducing device according to claim 15, the recording medium
storing the AV data, the associated data, and the file system
management information so that the AV data, the associated data,
and the file system management information are capable of being
supplied to the AV data reproducing device.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application is a continuation of copending application
U.S. Ser. No. 10/531,534, filed on Apr. 15, 2005, which is a
National Phase application filed under 35 USC 371 of PCT
International Application No. PCT/JP03/13209, filed on Oct. 15,
2003, which claims priority under 35 USC 119 to Japanese
Application No. 2002-303648, filed on Oct. 17, 2002, and Japanese
Application No. 2003-005058, filed on Jan. 10, 2003, all of which
are incorporated herein in their entireties.
TECHNICAL FIELD
[0002] The present invention relates to (i) a method for recording
image data and audio data onto a random accessible recording medium
such as a hard disk, an optical disc, and a semiconductor memory;
to (ii) a recording apparatus; and to (iii) a recording medium.
BACKGROUND ART
[0003] A video digital recording/reproducing apparatus
(hereinafter, referred to as "video disc recorder") using a disc
medium has begun to be pervasive. Required is a technique for
realizing, at an inexpensive price, an after-recording function in
such a video disc recorder, as is the case with a tape medium. The
after-recording function refers to a technique for further adding
information, especially audio information, to recorded audio
information and/or recorded video information.
[0004] A conventional technique for realizing such an
after-recording function using a disc medium was provided by the
present inventors, and is disclosed in Japanese Laid-Open Patent
Publication Tokukai 2001-43616 (published on Feb. 16, 2001). The
following briefly explains this technique with reference to FIG.
20(a) and FIG. 20(b).
[0005] In Japanese Laid-Open Patent Publication Tokukai 2001-43616,
a stream file 3000 is in compliance with a unique stream format,
and is so structured that regions for storing the after-recorded
data are inserted among original stream data (initially recorded
video/audio data) divided at a predetermined reproduction time
interval. The after-recorded data is reproduced in synchronism with
the original stream data. For example, FIG. 20(a) illustrates that
an after-recording data region 3011 for storing after-recorded
audio data that is to be reproduced in synchronism is inserted just
before partial original stream data 3021. Likewise, after-recording
data regions 3012 and 3013 are inserted just before partial
original stream data 3022 and 3023, respectively.
[0006] The stream file 3000 is recorded onto an optical disc 3001
such that each set of partial original stream data and each
after-recording data region are disposed physically adjacent to
each other as shown in FIG. 20(b). This minimizes seeking operation
during the synchronous reproduction of the partial original stream
data and the after-recorded data, and restrains interruption of the
reproduction due to the seeking operation. Further, a real-time
after-recording is ensured by setting reproduction time of the
partial original stream data to such a value (roughly several
seconds) that allows for the real-time after-recording and that is
determined in consideration of a seeking time.
[0007] Incidentally, examples of widely used data recording method
are: Transport Stream (hereinafter, referred to as "MPEG-2 TS") and
Program Stream (hereinafter, referred to as "MPEG-2 PS"), each of
which has a different structure from the stream structure described
in Japanese Laid-Open Patent Publication Tokukai 2001-43616, and
each of which is defined by ISO/IEC 13818-1. For example, MPEG-2 PS
is used for DVD-Video, and MPEG-2 TS is used for a data transfer
format between devices by way of digital broadcasting or the
IEEE-1394. Conventional after-recording techniques in consideration
of MPEG-2 PS/TS are described in Japanese Laid-Open Patent
Publication Tokukai 2000-306327 (published on Nov. 2, 2000), and
Japanese Laid-Open Patent Publication Tokukaihei 11-298845/1999
(published on Oct. 29, 1999).
[0008] However, in cases where the stream structure described in
Japanese Laid-Open Patent Publication Tokukai 2001-43616 is applied
to MPEG-2 PS/TS, a general decoder possibly cannot normally carry
out decoding for reproduction. A reason for this is explained as
follows.
[0009] It is determined in MPEG-2 TS/PS that video data and audio
data are multiplexed such that no underflow and no overflow occur
in respective buffer memories of an audio decoder and a video
decoder that are in compliance with a decoder model set as a
standard (reference). However, in the stream structure of Japanese
Laid-Open Patent Publication Tokukai 2001-43616, audio data
corresponding to one second or longer is stored in each of the
after-recording data regions. When such a stream file is reproduced
by using a general MPEG-2 TS/PS decoder, the MPEG-2 TS/PS decoder
receives, at a time, the audio data corresponding to one second or
longer. This causes overflow of the buffer memory of the audio
decoder.
[0010] Further, according to the after-recording function described
in Japanese Laid-Open Patent Publication Tokukai 2000-306327, the
after-recording data region is multiplexed in the stream in
accordance with the aforementioned MPEG-2 PS multiplexing rule;
however, the after-recording function suffers from a difficulty in
the real-time after-recording when a transfer rate to or from a
disc is low.
[0011] On the other hand, in Japanese Laid-Open Patent Publication
Tokukaihei 11-298845/1999, the after-recorded data and the original
stream data are recorded onto different files such that each of the
files is in compliance with the MPEG-2 PS multiplexing rule. In
this case, a file containing the after-recorded data and a file
containing the original stream data are alternately read out, so
that a seeking operation is required to be repeated during the
reproduction of the after-recorded result. For this reason, when a
non-destructive editing is carried out with respect to the
after-recorded result, the seeking operation is more likely to
cause interruption of reproduction especially between scenes. The
non-destructive editing refers to an editing that is virtually
carried out by using reproduction route information instead of
using the stream data on a disc. Moreover, the technique is also
disadvantageous in power consumption.
[0012] The present invention is made in light of the problem, and
its object is to provide a data recording method that allows
reproduction and real-time after-recording in a general MPEG-2
PS/TS decoder, and allows less interruption of reproduction when a
non-destructive edit is carried out with respect to an
after-recorded result.
DISCLOSURE OF INVENTION
[0013] A method, of the present invention, for recording, onto a
recording medium, (i) AV data obtained by multiplexing a plurality
of sets of stream data in accordance with a predetermined
multiplexing rule, and (ii) associated data to be reproduced in
synchronism with the AV data, the method includes: (a) a first step
of dividing the AV data into partial AV data and of dividing the
associated data into partial associated data, in accordance with a
predetermined interval; (b) a second step of securing, in the
recording medium, a first continuous region for continuously
storing a series of the partial AV data and the partial associated
data; (c) a third step of continuously recording the partial AV
data and the partial associated data onto the first continuous
region; and (d) a fourth step of recording, onto the recording
medium, file system management information for (i) managing the
partial AV data and the partial associated data as different files,
and (ii) managing information for handling the partial AV data and
the partial associated data as the different files.
[0014] With the arrangement, the AV data (e.g., original stream)
and the associated data (e.g., after-recorded data), which are to
be recorded onto the recording medium, are respectively divided
into the sets of the partial AV and the partial associated data by
performing the first step. With this, the partial AV data and the
partial associated data have such scales (lengths) that ensure the
seamless reproduction and the real-time after-recording,
respectively.
[0015] The partial AV data and the partial associated data thus
obtained by the dividing are reproduced in synchronism with each
other, and the partial AV data and the partial associated data are
continuously recorded by performing the second step and the third
step such that they are physically adjacent to each other.
[0016] Further, the file system management information recorded in
the fourth step manages the partial AV data and the partial
associated data as different files. This ensures the real-time
after-recording, and allows reproduction with the use of a general
MPEG-2 PS decoder whose non-destructive editing property is
excellent. Because the partial AV data and the partial associated
data are positioned adjacent to each other, the seeking occurs less
frequently when the AV data and the associated data are reproduced
in synchronism. That is, this provides margin for further
synchronized reproduction with other data. For example, the
reproduction is less likely to be interrupted even when graphics
data is added as well as the after-recorded audio data by way of
the non-destructive editing.
[0017] The file system management information managing the partial
AV data and the partial associated data as different files has the
information indicating the correspondence relation between the
partial AV data and the partial associated data, which are
positioned adjacent to each other in the recording medium. By
recording the information indicating the correspondence relation,
it is possible to easily recognize respective positions of the
continuously stored partial AV data and partial associated data
even when the file system management information is not referred.
This optimizes the data readout.
[0018] The method of the present invention may further include: a
fifth step of recording, onto the recording medium, (i)
reproduction start time of the partial AV data, and (ii)
correspondence information of the partial AV data and the partial
associated data, both of which are disposed in the first continuous
region.
[0019] The arrangement allows easy specification of the position of
the partial associated data (after-recording region) corresponding
to the partial AV data to be after-recorded.
[0020] The method of the present invention may further include: a
sixth step of recording, onto the recording medium, information
indicating whether or not the partial associated data is recorded
adjacent to the corresponding partial AV data.
[0021] In cases where defect occurs during the recording of the
partial AV data and the partial associated data, the partial
associated data being recorded is possibly discarded and the CA is
newly recorded onto another region.
[0022] To accommodate to such a case, the information managing the
partial associated data indicates that no partial associated data
is positioned adjacent to the relevant AV data. Therefore, it is
possible to easily recognize parts in which the partial AV data and
the partial associated data are not continuously recorded, during
the non-destructive editing or reproduction of the
non-destructively edited result. With this, the user can be
notified in advance that the reproduction will be likely to be
interrupted during the reproduction of the parts.
[0023] Another method for recording, onto a recording medium, (i)
AV data obtained by multiplexing a plurality of sets of stream data
in accordance with a predetermined multiplexing rule, and (ii)
associated data to be reproduced in synchronism with the AV data,
the method includes: (a) a seventh step of dividing the AV data
into partial AV data in accordance with a predetermined interval;
(b) an eighth step of securing, in the recording medium, a first
continuous region for continuously storing (i) a series of the
partial AV data and (ii) partial reservation data for securing,
during recording of the associated data, a region for storing
partial associated data that is so divided as to correspond to the
partial AV data; (c) a ninth step of continuously recording the
partial AV data and the partial reservation data onto the first
continuous region, while making sets of the partial reservation
data; and (d) a tenth step of recording, onto the recording medium,
file system management information for (i) managing the partial AV
data and the partial reservation data as different files, and (ii)
managing information for handling the partial AV data and the
partial reservation data as different files.
[0024] With the arrangement, the AV data (e.g., original stream) to
be recorded onto the recording medium is divided into partial AV
data by performing the seventh step such that the partial AV data
has a length (scale) that ensures the seamless reproduction and the
real-time after-recording.
[0025] The partial AV data thus obtained by the dividing and the
partial reservation data are continuously recorded by performing
the eighth step and the ninth step such that they are physically
positioned adjacent to each other. The partial reservation data
secures the region for storing the partial associated data that is
to be reproduced in synchronism with the partial AV data.
[0026] Further, the file system management information recorded in
the tenth step manages the partial AV data and the partial
associated data as different files. This ensures the real-time
after-recording during the recording of the associated data, and
allows reproduction with the use of a general MPEG-2 PS decoder
whose non-destructive editing property is excellent.
[0027] The method may further include: (a) a eleventh step of
dividing, during the recording of the associated data, the
associated data into partial associated data in accordance with a
predetermined interval; (b) a twelfth step of recording, during the
recording of the associated data, the partial associated data onto
the region secured by the partial reservation data which is stored
in continuity with the partial AV data corresponding to the
associated data; (c) a thirteenth step of recording, onto the
recording medium during the recording of the associated data, file
system management information for (i) managing the partial
associated data as a different file from the respective files of
the partial AV data and the partial reservation data, (ii) managing
information for handling the partial associated data as a different
file.
[0028] With the arrangement, the partial AV data and the partial
associated data are positioned adjacent to each other, so that the
seeking occurs less frequently when the AV data and the associated
data are reproduced in synchronism. That is, this provides margin
for further synchronized reproduction with other data. For example,
the reproduction is less likely to be interrupted even when
graphics data is added as well as the after-recorded audio data by
way of the non-destructive editing.
[0029] The file system management information managing the partial
AV data and the partial associated data as different files has the
information indicating the correspondence relation between the
partial AV data and the partial associated data, which are
positioned adjacent to each other in the recording medium. By
recording the information indicating the correspondence relation,
it is possible to easily recognize respective positions of the
continuously stored partial AV data and partial associated data
even when no reference to the file system management information is
made. This optimizes the data readout.
[0030] Additional objects, features, and strengths of the present
invention will be made clear by the description below. Further, the
advantages of the present invention will be evident from the
following explanation in reference to the drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0031] FIG. 1(a) and FIG. 1(b) illustrates an embodiment of the
present invention. FIG. 1(a) illustrates respective data structures
of an original stream file and an after-recording data file. FIG.
1(b) illustrates respective positions, in a disc, of data of the
original stream file and the after-recording data file.
[0032] FIG. 2 is a block diagram schematically illustrating a
structure of a video disc recorder according to embodiments of the
present invention.
[0033] FIG. 3(a) illustrates a directory/file structure. FIG. 3(b)
illustrates relation among sets of management information of the
directory/file structure in the UDF.
[0034] FIG. 4 illustrates a file/directory structure in Embodiment
1 of the present invention.
[0035] FIG. 5(a) through FIG. 5(c) each illustrate a structure of
an original stream file in Embodiment 1 of the present
invention.
[0036] FIG. 6 is an explanatory diagram illustrating a structure of
an after-recording data file in Embodiment 1 of the present
invention.
[0037] FIG. 7 illustrates a reference device model in Embodiment 1
of the present invention.
[0038] FIG. 8 illustrates a reference after-recording algorism in
Embodiment 1 of the present invention.
[0039] FIG. 9 illustrates a structure of a stream management
information file in Embodiment 1 of the present invention.
[0040] FIG. 10(a) and FIG. 10(b) each illustrate a structure of
video_unit_table in Embodiment 1 of the present invention.
[0041] FIG. 11(a) and FIG. 11(b) each illustrate a structure of
VU_flags in Embodiment 1 of the present invention.
[0042] FIG. 12(a) and FIG. 12(b) each illustrate a structure of
continuous_area_table in Embodiment 1 of the present invention.
[0043] FIG. 13(a) and FIG. 13(b) illustrate a structure of CA_flags
in Embodiment 1 of the present invention.
[0044] FIG. 14 illustrates a structure of a program information
file in Embodiment 1 of the present invention.
[0045] FIG. 15(a) and FIG. 15(b) illustrate a structure of
scene_table in Embodiment 1 of the present invention.
[0046] FIG. 16 is a flowchart illustrating a flow of recording
processes in Embodiment 1 of the present invention.
[0047] FIG. 17 is a flowchart illustrating a flow of reproduction
processes in Embodiment 1 of the present invention.
[0048] FIG. 18 is a flowchart illustrating a flow of scene
reproduction processes in Embodiment 1 of the present
invention.
[0049] FIG. 19(a) and FIG. 19(b) illustrate another embodiment of
the present invention. FIG. 19(a) illustrates respective data
structures of two kinds of stream files in Embodiment 2 of the
present invention. FIG. 19(b) illustrates how respective data in
the stream files is positioned in a disc.
[0050] FIG. 20(a) and FIG. 20(b) illustrate a conventional
technique. FIG. 20(a) illustrates a data structure of a stream
file. FIG. 20(b) illustrates how data in the stream file is
positioned in a disc.
[0051] FIG. 21 illustrates a file/directory structure in Embodiment
3 of the present invention.
[0052] FIG. 22(a) and FIG. 22(b) illustrate one embodiment of the
present invention. FIG. 22(a) illustrates respective data
structures of an original stream file and an after-recording region
reservation file in Embodiment 3 of the present invention. FIG.
22(b) illustrates how respective data of the original stream file
and the after-recording region reservation file are positioned in
the disc just after picture recording.
[0053] FIG. 23(a) illustrates respective data structures of a
graphics file and an after-recording data file in Embodiment 3 of
the present invention. FIG. 23(b) illustrates how the graphics
file, the after-recording data file, and the original stream file,
and the after-recording region reservation file are positioned in
the disc just after the after-recording and non-destructive
editing.
[0054] FIG. 24 illustrates a structure of a program information
file in Embodiment 3 of the present invention.
[0055] FIG. 25(a) and FIG. 25(b) illustrate subaudio_table in
Embodiment 3 of the present invention.
[0056] FIG. 26(a) and FIG. 26(b) illustrate graphics_table in
Embodiment 3 of the present invention.
[0057] FIG. 27(a) and FIG. 27(b) illustrate SA_flags and gr_flags
in Embodiment 3 of the present invention.
[0058] FIG. 28 is a flowchart illustrating a flow of a scene
reproduction processes in Embodiment 3 of the present
invention.
[0059] FIG. 29(a) and FIG. 29(b) illustrate one embodiment of the
present invention. FIG. 29(a) illustrates respective data
structures of an original stream file and an after-recording data
file in Embodiment 4 of the present invention. FIG. 29(b)
illustrates how respective data in the original stream file and the
after-recording data file are positioned in the disc.
[0060] FIGS. 30(a) and 30(b) illustrate a reference after-recording
algorism in Embodiment 4 of the present invention.
BEST MODE FOR CARRYING OUT THE INVENTION
[0061] The following description deals with detailed description of
Embodiments of the present invention with reference to figures.
Firstly explained here is a structure commonly used in the present
invention, and subsequently explained are unique things in
respective Embodiments. Note that the present invention is not
limited to these.
[0062] <System Structure>
[0063] FIG. 2 is a block diagram illustrating a basic system of a
video disc recorder that is common in Embodiments described
below.
[0064] As shown in FIG. 2, the video disc recorder includes: a bus
100, a host CPU 101, a RAM 102, a ROM 103, a user interface 104, a
system clock 105, an optical disc 106, a pickup 107, an ECC (Error
Correcting Coding) decoder 108, an ECC encoder 109, an audio
reproduction buffer 110, a video reproduction buffer 111, a
de-multiplexer 112, a multiplexer 113, a recording buffer 114, an
audio decoder 115, a video decoder 116, an audio encoder 117, a
video encoder 118, an audio recording buffer 119, a video recording
buffer 120, a de-multiplexer 121, an after-recording data
reproduction buffer 122, a dividing processing section 123 (means
for dividing into AV data and partial associated data), a vacant
region management section 125 (means for securing a continuous
region), a management information processing section 126, a camera
(not shown), a microphone (not shown), a speaker (not shown), a
display (not shown), and the like. The pickup 107, the ECC decoder
108, and the ECC encoder 109 constitute a drive 127 (means for
continuously recording partial AV data and the partial associated
data; means for recording file system management information onto
the recording medium).
[0065] The host CPU 101 controls, via the bus 100, the
de-multiplexer 112, the multiplexer 113, the pickup 107, the audio
decoder 115, the video decoder 116, the audio encoder 117, and the
video encoder 118.
[0066] During reproduction, data read out from the optical disc 106
via the pickup 107 is subjected to an error correction carried out
by the ECC decoder 108. In the data thus subjected to the error
correction, file system management information is processed by the
management information processing section 126. Then, the data is
sent to the de-multiplexer 112 or de-multiplexer 121.
[0067] According to an instruction from the host CPU 101, the
de-multiplexer 112 sends audio data of the readout data to the
audio reproduction buffer 110, and sends video data thereof to the
video reproduction buffer 111. Likewise, the de-multiplexer 121
sends the readout data to the after-recording data reproduction
buffer 122 in accordance with an instruction from the host CPU
101.
[0068] The audio decoder 115 reads out the data from the audio
reproduction buffer 110 and the after-recording data reproduction
buffer 122, and carries out decoding with respect to the readout
data, in accordance with an instruction from the host CPU 101.
Likewise, the video decoder 116 reads out the data from the video
reproduction buffer 111, and carries out decoding with respect to
the readout data, in accordance with an instruction from the host
CPU 101.
[0069] On the other hand, during recording, data compressed and
encoded by the audio encoder 117 is sent to the audio recording
buffer 119, and data compressed and encoded by the video encoder
118 is sent to the video recording buffer 120. According to an
instruction from the host CPU 101, the multiplexer 113 reads out
the respective data from the audio recording buffer 119 and the
video recording buffer 120, and carries out AV-multiplexing with
respect to the readout data, and sends the AV-multiplexed data to
the dividing processing section 123. The dividing processing
section 123 divides the AV-multiplexed data at every predetermined
interval, and sends the divided data to the recording buffer 114.
On this occasion, the vacant region management section 125 secures
a continuous region for the recording of the data, and the ECC
encoder 109 adds an error correction code to the AV-multiplexed
data read out from the recording buffer 114, and the pickup 107
records the data onto the secured continuous region in the optical
disc 106.
[0070] An encoding format of the audio data is MPEG-1 Layer-II
defined by ISO/IEC 13818-3, and an encoding format of the video
data is MPEG-2 defined by ISO/IEC13818-2. The optical disc 106 is a
re-writable optical disc, such as DVD-RAM, in which 2048 byte is
handled as one sector and in which 16 sectors constitute an ECC
block for the sake of the error correction.
[0071] <File System>
[0072] The following explains a UDF (Universal Disk Format) adopted
as a format of a file system used in the description of the present
invention, with reference to FIG. 3(a) and FIG. 3(b). FIG. 3(a)
illustrates a directory/file structure, and FIG. 3(b) illustrates
an example in which the directory/file structure is recorded in
compliance with the UDF.
[0073] An AVDP (Anchor Volume Descriptor Pointer) 602 shown in FIG.
3(b) corresponds to an entry point for a search for management
information of the UDF, and is usually recorded in a 256-th sector,
an N-th sector, or an (N-256)-th sector (N refers to a maximum
logical sector number). A VDS (Volume Descriptor Sequence) 601
stores management information about a volume. The volume is a
region managed by the UDF, and one volume generally exists in one
disc, and generally includes one partition. One FSD (File Set
Descriptor) 603 exists in the partition. Position information in
the partition is indicated by a logic block number that corresponds
to a sector number counted from top of the partition. Note that one
logic block corresponds to one sector. Note also that each
partition (not shown) includes a table indicating whether or not a
logic block termed "space bitmap" has been allocated to each
file.
[0074] The FSD 603 includes position information of an FE 604
serving as a file entry (FE) of a root directory. The position
information is referred to as "extent" including logic block
numbers and the number of the logic blocks. The FE manages an
aggregate of the extents. By rewriting, adding, and/or deleting
each extent, it is possible for the FE to change order of sets of
actual data constituting the file, and/or to carry out data
insertion and data deletion.
[0075] The FE 604 manages a region 605 storing an aggregate of file
identifier descriptors (FIDs), each of which stores name(s) of a
file and/or a directory just below the root directory. An FID 611
and an FID 612 in the region 605 include position information of FE
606 and FE 608, respectively. The FE 606 manages a filename of a
file 621 and an aggregation of extents thereof, and the FE 608
manages a filename of a file 622 and an aggregation of extents
thereof. Specifically, the FE 606 manages, as the extents, a region
607 and a region 610, each of which is a region constituting the
actual data of the file 621. An access to the actual data of the
file 621 can be made by following the links in order of the AVDP
602, the VDS 601, the FSD 603, the FE 604, the FID 611, the FE 606,
the region 607, and the region 610.
Embodiment 1
[0076] Embodiment 1 of the present invention will be explained
below with reference to FIG. 1, and FIG. 4 through FIG. 18.
[0077] <File/Directory Structure>
[0078] A file/directory structure according to Embodiment 1 is
explained with reference to FIG. 4. As shown in FIG. 4, data of
Embodiment 1 is stored in five types of files.
[0079] An original stream file (SHRP0001.M2P) is a file prepared
per picture recording, and is in compliance with the MPEG-2 PS
(Program Stream) format. An after-recording data file
(SHRP0001.PRE) is a file for (i) securing a region for
after-recording, and (ii) storing after-recorded data. An original
stream management information file (SHRP0001.OMI) is a file for
storing (i) time-address correspondence information about the
original stream file; (ii) attribution information about the
original stream file; (iii) attribution information about the
after-recording data file; and (iv) information indicative of a
correspondence correlation with the original stream file. The
original stream management information file is provided per
original stream file. A program information file (SHRP0001.PGM) is
a file for storing information that specifies which parts in the
stream or the data are to be reproduced and that specifies order of
reproducing these parts. Note that the program corresponds to one
of contents, and is a target to be reproduced in response to user's
instruction.
[0080] The four files above are newly prepared during a picture
recording. The files have different extensions, but are arranged so
that others are in common than the extensions for the purpose of
clarifying a relation among the files. During audio
after-recording, after-recorded audio data is overwritten in a
predetermined location of the after-recording data file, and the
after-recording data management information file reflects the
overwriting. Moreover, the program information file is also changed
so that the added after-recorded audio data is also a target to be
reproduced.
[0081] During the non-destructive editing, the program information
file is newly prepared, and stores one by one (i) filenames of the
original stream management information file and/or the
after-recording data management information file, each of which
manages the data to be reproduced; and (ii) the parts of the data
which the user wishes to reproduce. Note that respective data
structures of the files will be explained later.
<A structure of an AV Stream>
[0082] The following description explains a structure of an AV
stream in Embodiment 1 with reference to FIG. 5.
[0083] Firstly, the original stream file is explained with
reference to FIG. 5. Content of the original stream file is in
compliance with the MPEG-2 PS format, and is constituted by the
integral number of continuous units (CUs) as shown in FIG. 5(a).
Each CU is a recording unit by which the recording is carried out
with respect to a disc. Length of the CU is so set as to ensure (i)
seamless reproduction (reproduction during which an image and a
sound are never interrupted) and (ii) real-time after-recording
(audio recording carried out during a seamless reproduction of
video to be subjected to the after-recording), irrespective of how
the CUs constituting the AV stream are provided on the disc. A
method for setting the length will be described later.
[0084] Each CU is constituted by the integral number of video units
(VUs) as shown in FIG. 5(b). Each VU is a individually reproducible
unit, and can be an entry point during a reproduction. The VU is
constituted by the integral number of audio packs (A#1 through A#K)
and video packs (V#1 through V#L). The audio packs and the video
packs are so AV-multiplexed as to maintain an MPEG-2 PS compatible
decoder model. A size of each pack is as large as a sector size
such that excess data is not read out during readout of the disc.
Note that the video data to be packed is constituted by one or two
GOPs (Groups of picture). Note also that the audio data to be
packed is constituted by the integral number of AAUs (Audio Access
Units).
[0085] Note that the GOP is a unit of image compression of the
MPEG-2 video standard, and is constituted by a plurality of video
frames (typically, 15 frames or so). The AAU is a unit of audio
compression of the MPEG-1 Layer-II standard, and is constituted by
1152 sound waveform sample points. In cases where a sampling
frequency is 48 kHz, reproduction time per AAU is 0.024 second.
Further, a sequence header (SH) is provided at a head of video data
in each VU such that individual reproductions are carried out in
the VU unit.
[0086] Note that a VU at the end of the CU is padded by a pack
storing a padding packet such that the CU is constituted by the
integral number of ECC blocks.
[0087] <After-Recording Data File>
[0088] The following explains a structure of the after-recording
data file with reference to FIG. 6. As shown in FIG. 6, the
after-recording data file is constituted by the integral number of
continuous areas (CAs). One CA corresponds to one CU in the
original stream file, and stores after-recording data corresponding
to the reproduction data of the corresponding CU. For example, a
CA#n stores after-recording audio data that is to be reproduced in
synchronization with a CU#n of the original stream file. The CA is
constituted by the integral number of ECC block(s).
[0089] The after-recording data file is in compliance with the
MPEG-2 PS format as the original stream file is. During initial
picture recording, padding packets are recorded onto the
after-recording data file. After the after-recording, packs
containing the after-recorded data are overwritten in the
after-recording data file. The packs to be overwritten have SCRs
(System Clock References) in pack headers and have PTSs
(Presentation Time Stamps) in packet headers, respectively. The
SCRs and the PTSs suit to SCRs and PTSs of the corresponding audio
packs in the original stream file, respectively. With this, the
audio data of the original stream can be easily replaced with the
after-recorded data by overwriting the audio packs of the CU with
the corresponding audio packs of the CA.
[0090] <Layout in the Disc>
[0091] The following description explains how respective data of
the original stream file and the after-recording data file are
disposed in the disc with reference to FIGS. 1(a) and (b). FIG.
1(a) illustrates the original stream file (SHRP0001.M2P) and the
after-recording data file (SHRP0001.PRE), which correspond to each
other. The original stream file and the after-recording data file
are recorded onto the optical disc 106 such that the CAs come just
before the corresponding CUs, respectively (see FIG. 1(b)).
[0092] With this, the data (each CA and each CU) to be reproduced
in synchronism are positioned adjacent to each other on the disc.
This minimizes a movement of the pickup during reproduction.
Accordingly, the interruption is less likely to occur during
reproduction of a non-destructively edited result as described
below. Because such a small CA in size is so positioned as to be
read out prior to the CU, less buffer memory amount can be used for
the synchronized reproduction.
[0093] <Method for Determining a CU Scale>
[0094] A method for determining reproduction time of the CU will be
explained with reference to FIG. 7 and FIG. 8. In the method, the
reproduction time of the CU is determined such that the seamless
reproduction is maintained when the after-recording is carried out
by using, for sake of ensuring compatibility between devices, (i) a
reference device (reference device model); and (ii) a reference
after-recording algorism.
[0095] Firstly explained is the reference device model with
reference to FIG. 7. The reference device model is made up of a
pickup (not shown); an ECC encoder/decoder 501 connected to the
pickup; a track buffer 502; a de-multiplexer 503; an
after-recording buffer 504; an audio encoder 509; a video buffer
505; an audio buffer 506; a video decoder 507; and an audio decoder
508.
[0096] Because the reference device model has the single pickup,
readout of reproduction data from a disc 500 and recording of
after-recorded data onto the disc 500 are carried out in a
time-sharing manner. The reproduction data is read out from the
disc 500 together with the CA. An ECC block (CA block) including
the readout CA is sent from the track buffer 502 to the
after-recording buffer 504.
[0097] The audio encoder 509 sends the after-recorded data to the
after-recording buffer 504 in a cycle of the AUU. The output data
is overwritten in the corresponding CA block in the after-recording
buffer 504. The CA block is recorded onto a predetermined ECC
block, with the result that the after-recorded data is
recorded.
[0098] Here, it is assumed that Rs indicates both (i) a
transmission speed of the audio frame data to the ECC encoder 501,
and (ii) a transmission speed of the audio frame data from the ECC
decoder 501. It is further assumed that Ta indicates a maximum
period during which the readout and the recording are suspended via
an access. Note that the period Ta includes seeking time, rotation
latency time, and time required for completing of outputting, from
the ECC decoder 501, of the data initially read out after the
access. Embodiment 1 assumes that Rs is 20 Mbps and Ta is one
second.
[0099] Next, the reference after-recording algorithm will be
explained with reference to FIG. 8. Note that numbers {circle
around (1)} to {circle around (6)} in FIG. 8 respectively
correspond to the following numbers {circle around (1)} to {circle
around (6)} which describe the algorithm briefly as follows:
{circle around (1)} Read out data for reproduction. {circle around
(2)} Make an access to a CA(N), which is an n-th CA, concurrently
with completion of encoding of audio data that corresponds to the
CA(N). {circle around (3)} Recording the CA(N) onto the disc.
{circle around (4)} Go back to the readout position where the
pickup was. {circle around (5)} Read out the data for reproduction.
{circle around (6)} Make an access to a CA(N+1), which is an
(n+1)-th CA, concurrently with completion of encoding of audio data
that corresponds to the CA(N+1). After that, operations {circle
around (3)} through {circle around (6)} are repeated.
[0100] The after-recording, using the reference after-recording
algorithm in the reference device model, ensures that the
after-recording buffer 504 is free from overflow and that the track
buffer 502 is free from underflow, as long as the following
condition is satisfied:
Te(i).gtoreq.Tr(i)+Tw(i) (1)
where Te(i) indicates maximum reproduction time of a CU#i that is
an arbitrary CU in the AV stream; Tr(i) indicates maximum readout
time including a division jump; and Tw(i) indicates maximum time
for recording a CA#i that corresponds to the CU#.
[0101] This is because Formula (1) satisfies a sufficient condition
of the seamless reproduction. The condition is represented by the
following Formula (2):
i Te ( .gtoreq. i ) i ( Tr ( i ) + iT ( 2 ) ##EQU00001##
[0102] where Ta indicates maximum round-trip time for the pickup to
go to and return from the CA in the disc.
[0103] Because the after-recorded data is recorded onto the disc in
synchronization with the completion of the encoding of the CA, data
never keeps being accumulated in the after-recording buffer 504 and
the after-recording buffer 504 is therefore free from the
overflow.
[0104] Tr(i) in Formula (1) satisfies the following Formula
(3):
Tr(i)=Te(i).times.Ro/Rs+Te(i).times.Ra/Rs+Ta (3)
where Ro indicates maximum bit rate of the original stream, Ra
indicates maximum bit rate of the after-recording audio stream, and
Rs indicates input speed and output speed of the audio frame data,
i.e., indicates audio bit rate.
[0105] A first term in a right side of Formula (3) indicates time
for reading out a VU in a CU, and a second term therein indicates
time for reading out the CA, and a third term therein indicates
time for an access made by the division jump associated with the
readouts. The division jump is carried out once at the maximum
during the readout of the CU, so that Formula (3), i.e., Tr(i)
indicates time corresponding to one access operation.
[0106] Tw(i) satisfies the following Formula (4):
Tw(i)=2Ta+Te(i).times.Ra/RS (4)
[0107] Here, a first term in a right side of Formula (4) indicates
access time (forward-backward access time) for the pickup to go to
and come back from the CA. The maximum access time Ta is used to
represent the forward-backward access time because each CA can be
recorded onto any position in the disc. Specifically, there is such
a possibility that a CU which is being read out is positioned in an
innermost side of the disc, and that a CA to be recorded is
positioned in an outermost side of the disc. For this reason, the
forward-backward access time is required to be estimated at the
maximum value.
[0108] Note that the CA is recorded continuously onto the disc as
described above, so that no access is made during the recording of
the CA. This shortens time required for the recording of the CA,
with the result that a lower limit value of the reproduction time
of the CU can be restrained to be low.
[0109] When Formula (3) and Formula (4) are substituted in Formula
(1) to solve for Te(i), a condition of Te(i) that ensures the
real-time after-recording can be obtained as the following Formula
(5):
Te(i).gtoreq.(3Ta.times.Rs)/(Rs-Ro-2Ra) (5)
Indicated by Rv is input speed and output speed of the video frame
data, i.e., is video bit rate.
[0110] Accordingly, the CU reproduction time lower limit value
Temin that ensures the after-recording is represented by the
following formula (6):
Temin=(3Ta.times.Rs)/(Rs-Ro-2Ra) (6)
[0111] A CU reproduction time upper limit value Temax is so set as
to satisfy the following Formula (7):
Temax=(3Ta.times.Rs)/(Rs-Ro-2Ra)+Tvmax (7)
where Tvmax indicates maximum reproduction time of the VU.
[0112] The setting of the upper limitation value of the CU
reproduction time is carried out so as to allow for estimation of
maximum amount of the retardation memory required for the
synchronized reproduction of the after-recorded audio and the
normal audio, and so as to ensure reproduction compatibility. Note
that, in Embodiment 1, the multiplexing interval lower limit value
Temin is set according to the audio bit rate Ra and the video bit
rate Rv; however, the lower limit value may be constant at any
value as long as the lower limit value is based on maximum bit
rate.
[0113] Moreover, reproduction time of the VU in the stream may be
constant or variable as long as the reproduction time of the CU
meets the aforementioned restriction.
[0114] Further, Embodiment 1 assumes that the division jump and the
movement of the pickup to a previous CU are asynchronously carried
out. A reason for this is as follows. That is, a condition for the
real-time after-recording is stricter (the readout of the
reproduction data is interrupted for a longer period of time) in
cases where the division jump and the movement are asynchronously
carried out, as compared with cases where the division jump and the
movement are synchronously carried out. In other words, in cases
where the real-time recording is attained when the division jump
and the movement are asynchronously carried out, the real-time
recording is accordingly attained when the division jump and the
movement are synchronously carried out. This allows an increase in
freedom of implementation of the present invention.
[0115] Therefore, Temin may be set on an assumption that the
division jump and the movement of the pickup to the previous CU are
carried out in synchronism. In this case, the second term in the
right side of Formula 3 is omitted.
<Formats of Management Information Files>
[0116] The following description explains management information
file formats according to the present invention with reference to
FIG. 9 through FIG. 15.
[0117] Firstly explained is the original stream management
information file. As shown in FIG. 9, the original stream
management information file is made up of (i) o_attribute( ) for
storing attribution information about the entire original stream
file managed by the original stream management information file;
(ii) video_unit_table( ) for storing information about the VU;
(iii) p_attribute( ) for storing attribution information about the
entire after-recording data file managed by the original stream
management information file; and (iv) continuous_area_table( ) for
storing information about the CA.
[0118] As shown in FIG. 10(a), the video_unit_table( ) is made up
of (i) number_of video_unit for indicating the number of the VUs;
and (ii) video_unit_info( ) for storing information about each of
the VUs.
[0119] As shown in FIG. 10(b), the video_unit_info( ) is made up of
(i) VU_flags for indicating various kinds of attribution
information about a predetermined VU; (ii) VU_PTS for storing a PTS
(Presentation Time Stamp) of a top display frame of a predetermined
VU; and (iii) VU_PN for indicating relative pack numbers counted
from a top of the file. The VU_PTS and the VU_PN make it possible
to specify a position of a VU corresponding to a specific PTS.
Namely, the VU_PTS indicates reproduction start time of the
original stream (AV data).
[0120] As shown in FIG. 11(a), the VU_flags( ) includes
first_unit_flag. The first_unit_flag is 1-bit information. As shown
in FIG. 11(b), the first_unit_flag indicative of 0b means that a
managed VU is not positioned in the head of the CU, whereas the
first_unit_flag indicative of 1b means that a managed VU is
positioned in the head of the CU.
[0121] As shown in FIG. 12(a), the continuous_area_table( ) is made
up of (i) number_of continuous_area for indicating the number of
the CAs; and (ii) continuous_area_info( ) for storing information
about each of the CAs.
[0122] As shown in FIG. 12(b), the continuous_area_info( ) is made
up of (i) CA_flags for indicating various kinds of attribution
information about a predetermined CA; (ii) CA_PTS for storing a PTS
(Presentation Time Stamp) of a top display frame of a CU
corresponding to the CA; and (iii) CA_PN for indicating relative
pack numbers counted from a top of the file. The CA_PTS and the
CA_PN make it possible to specify a position of a CA corresponding
to a specific PTS in the original stream. The CA_PN indicates
position information of a first continuous region for recording the
CA and the CU, in other words, the CA_PN indicates head position
information of the CA.
[0123] As shown in FIG. 13(a), the CA_flags( ) includes
"placement_flag". The placement_flag is 1-bit information. As shown
in FIG. 13(b), the placement_flag indicative of 0b means that a
managed CA is not positioned just before a corresponding CU (that
is to be reproduced in synchronism with the CA), whereas the
placement_flag indicative of 1b means that a managed CA is
positioned just before a corresponding CU (that is to be reproduced
in synchronism with the CA).
[0124] Making reference to the flag allows for realization whether
or not the non-destructively edited result possibly cause the
interruption during the reproduction. Specifically, seeking of the
CA is carried out when the placement_flag is indicative of 0b. This
notifies that the reproduction is highly likely to be
interrupted.
[0125] Note that explanation of the o_attribute( ) and the
p_attribute( ) is omitted.
[0126] Finally explained is the program information file. As shown
in FIG. 14, the program information file is made up of (i)
pg_attribute( ) for storing attribution information of entire
program information; and (ii) scene_table( ) for storing
information about scenes constituting the program.
[0127] As shown in FIG. 15(a), the scene_table( ) is made up of (i)
number_of scene for storing the number of the scenes; and (ii)
scene_info( ) for storing information about each of the scenes. As
shown in FIG. 15(b), the scene_info( ) is made up of (i)
sc_filename for storing a filename of the original stream
management information file that manages the original stream file
containing a predetermined scene; (ii) sc_start_PTS for storing
information indicating a position from which the scene is
reproduced; and (iii) sc_duration for storing reproduction time of
the scene.
[0128] <Processes During Recording>
[0129] The following explains processes performed in response to
the user's instruction for picture recording, with reference to a
flowchart of FIG. 16. Note that an AV stream to be recorded on this
occasion has a bit rate Ro of 12 Mbps, and has an audio bit rate Ra
of 256 kbps, and is such a stream that is in compliance with the
constant VU reproduction time method. Note also that, the following
assumes that the management information of the file system has
already been in the RAM.
[0130] Firstly carried out is determination of a stream structure
and a structure of the continuous region (S701). When each VU is
constituted by one GOP made up of 15 frames, substituted in Formula
(6) and Formula (7) are the following conditions: Rs=20 Mbps, Ta=1
second, Rv=12 Mbps, Ra=256 kbps, and Tvmax=approximately 0.5
second. With this, Te(i) falls within a range from 3 seconds to 4
seconds. When Tvmax is approximately 0.5 second, Te(i) satisfying
this condition is 3 seconds. In this case, each CA is inserted in
the AV stream for every 6 VUs.
[0131] A region size for the CA in this case is determined in
consideration of a pack header and a packet header, both of which
are attached to the audio data corresponding to 3 seconds. The
above process in S701 corresponds to a first step of dividing,
according to the predetermined interval, the original stream
serving as the AV data into the partial AV data (CU, i.e., 6 VUs),
and dividing, according to the predetermined interval, the
after-recorded data serving as the associated data of the AV data
into the partial associated data.
[0132] Then, a search is carried out for a vacant region capable of
continuous storage of the 6 VUs and one CA, with reference to the
Space Bitmap in the RAM 102. When no vacant region is found, the
picture recording is stopped, and the user is notified that the
recording cannot be carried out (S702).
[0133] Next, the audio encoder 117 and the video encoder 118 are
launched (S703). After that, a check is carried out whether or not
data corresponding to one ECC block (32 KB) or greater is
accumulated in the recording buffer (S704). While the data is being
accumulated, processes S705 to S708 are repeated.
[0134] Specifically, when data corresponding to one ECC block or
greater is accumulated in the recording buffer, a search in the
disc is carried out for a next vacant ECC block for storing the
data, with reference to the Space Bitmap in the RAM (S705). Carried
out when vacancy is found is the recording, onto the disc, of the
data that corresponds to one ECC block and that is accumulated in
the recording buffer 111 (S706). When no vacancy is found, a search
is carried out for a continuous vacant region that can store the
nine VUs and the CA (S707). Then, the pickup is moved to the head
of the vacant region found by the search (S708). Carried out after
that is the recording, onto the disc, of the data that corresponds
to one ECC block and that is accumulated in the recording buffer
111 (S706).
[0135] The process in S704 corresponds to a second step of securing
a first continuous region for continuously storing the partial AV
data and the partial associated data. Moreover, the process in S706
corresponds to a third step of continuously recording the partial
AV data and the partial associated data onto the first continuous
region.
[0136] Meanwhile, when data accumulated in the recording buffer 111
is less than data corresponding to one ECC block, a check is
carried out whether or not an instruction for finishing the
recording has been made (S709). When such an instruction has not
been made, the sequence goes to S704.
[0137] On the other hand, when such an instruction has been made in
S709, the following processes are carried out. That is, dummy data
is provided at an end of the data that is accumulated in the
recording buffer and that is less than 32 KB, so as to cause the
accumulated data to have 32 KB (S710). Next, the data thus having
32 KB is recorded onto the disc (S711 through S714). Note that
processes in S711 through S714 are the same as the processes in
S705 through S708, respectively.
[0138] Carried out next is recording of (i) the management
information about the original stream onto the original stream
management information file; and of (ii) the management information
about the after-recorded data, onto the after-recording data
management information file (S715). Then, the file system
management information is recorded onto the optical disc 106
(S716). Note that the file system management information thus
recorded designates such that the CU and the CA are handled as
different files.
[0139] The process in S716 corresponds to a forth step of (i)
recording, onto the recording medium, the file system management
information for (i) managing the partial AV data and the partial
associated data as different files, (ii) managing information for
handling the partial AV data and the partial associated data as
files different from a file for securing the first continuous
region.
[0140] The process in S715 corresponds to a fifth step of
recording, onto the recording medium, (i) the reproduction start
time of the partial AV data, and (ii) the correspondence
information of the partial AV data and the partial associated data,
both of which are disposed in the first continuous region.
[0141] The following explains operations of the audio encoder 117,
the video encoder 118, and the multiplexer 113 during the
processes. Results obtained by encoding carried out by these
encoders are sent to the audio recording buffer 119 and the video
recording buffer 120, respectively. The multiplexer 113 multiplexes
the respective sets of data into MPEG-2 PS data, and then the
MPEG-2 PS data is stored in the recording buffer 114.
[0142] In cases where the recording buffer 114 receives a data
corresponding to one VU and where the VU is 9.times.i-th VU (i is
an integer equal to or larger than 0), a CA having the aforesaid
size is firstly sent to the recording buffer 111.
[0143] When the completion of the encoding of the data
corresponding to the VU is notified to the host CPU 101, the host
CPU 101 updates (i) the management information, in the RAM 102,
about the original stream; and (ii) the management information, in
the RAM 102, about the after-recorded data. The update is carried
out in accordance with the PTS at the head of the VU, the number of
packs constituting the VU, and the number of packs constituting the
CA.
[0144] [Processes During Reproduction]
[0145] The following description explains processes when the user
instructs reproduction of the program to which the after-recording
was carried out, with reference to a flowchart of FIG. 17. Note
that the following description assumes that the program information
file used in the reproduction has already been in the RAM 102.
[0146] Firstly, carried out in reference to the sc_filename of the
scene_info( ) in the program information file is opening of the
original stream file and the after-recording data file, each of
which is referred by the program. Simultaneously, the original
stream management information file managing these files is read out
(S901).
[0147] Next, the scene number is set at 0 (S902). While the scene
number is smaller than the number indicated by the number_of scene
in the scene_table (S903), below-described reproduction of the
scene is carried out with reference to content of the scene_info
corresponding to the scene number (S904). Upon completion of the
reproduction of the scene, numeral 1 is added to the scene number
(S905).
[0148] Next, processes of reproducing the scene will be explained
with reference to FIG. 18. Firstly carried out is a search for
video_unit_info( ) having the largest VU_PTS that is equal to or
smaller than the sc_start_PTS (S801), in reference to the
video_unit_table( ) of the original management information in the
RAM 102. The process in S801 is carried out to find a VU number of
the scene from which the reproduction starts. Note that the VU
number represents order of sets of the video_unit_info( ) of the
video_unit_table( ).
[0149] Carried out next is a search for continuous_area_info( )
having the largest CA_PTS that is equal to or smaller than
sc_start_PTS (S802), in reference to the continuous_area_table( ).
The process in S802 is carried out to find an address of the CA
corresponding to the scene from which the reproduction starts.
Thereafter, packs are read out from the after-recording data file,
those packs falling within a range from (i) a pack specified by a
CA_PN in the continuous_area_info( ), to (ii) a pack just before a
pack specified by a CA_PN in a next continuous_area_info
(S803).
[0150] Next, an address of the VU is found in reference to the
VU_PN of the video_unit_info( ) which corresponds to the present VU
number (S804). Based on the address, the VU is read out from the
original stream file (S805). Carried out next is judgment whether
or not the scene is over (S806). Specifically, when elapsed
reproduction time of the present scene is equal to or exceeds the
time specified by the sc_duration of the scene_info( ), the scene
is judged to be over.
[0151] In cases where the reproduction of the scene is not over,
numeral 1 is added to the VU number (S807). Then, carried out is
judgment whether or not the VU managed by the video_unit_info( ) is
positioned in the head of the CU, by referring to the
first_unit_flag of the video_unit_info( ) (S808).
[0152] When the first_unit_flag is indicative of 1, the VU managed
by the video_unit_info( ) is judged to be positioned in the head of
the CU, and the address of the CA is found by performing the
aforementioned step (S809). Thereafter, the CA is read out from the
after-recording file (S810). On the contrary, when the
first_unit_flag is indicative of 0, the VU managed by the
video_unit_info( ) is judged to be positioned not in the head of
the CU, and the processes from S804 to S808 are repeated.
[0153] During the readout of the stream and the data from the
optical disc 106, the decoding processes are carried out as
follows. The readout VU is sent to the de-multiplexer 112, and the
de-multiplexer 112 extracts a video PES packet and an audio PES
packet from the VU. The video PES packet is sent to the video
reproduction buffer 111, and the audio PES packet is sent to the
audio reproduction buffer 110.
[0154] The de-multiplexer 112 extracts a SCR from the pack header,
and updates the system clock 105. The video decoder 116 and the
audio decoder 115 carry out decoding and outputting at the moment
when the system clock 105 coincides with a time stamp attached to
the PES packet header.
[0155] In Embodiment 1, each CU storing the original stream is
physically adjacent, in the disc, to each CA storing the
after-recorded data to be reproduced in synchronism with the CU.
For this reason, even when the scene starts from a VU positioned in
the vicinity of a terminal of the CU, the seeking of the VU by
moving the pickup from the position of the CA requires only a
little suspension time during the data readout.
[0156] On the contrary, in the case where the after-recorded data
is not positioned adjacent to the original stream to be reproduced
in synchronism, the seeking time between (i) the readout of the
after-recorded data in the head portion of the scene and (ii) the
readout of the original stream corresponds to, at worst, such time
that the pickup moves from the innermost side of the disc to the
outermost side of the disc. Accordingly, the reproduction in this
case is highly likely to be interrupted between the scenes as
compared with the present embodiment.
[0157] [Processes During after-Recording]
[0158] The following explains processes carried out in response to
the user's instruction to perform the after-recording. The
processes during the after-recording are carried out by performing
several processes in addition to the aforementioned reproduction
processes. For this reason, explanation here is made only for those
differences from the above-described processes.
[0159] Firstly, for the recording of the after-recorded data, the
audio encoder 117 is launched concurrently with a reproduction
start of the scene. A result obtained by encoding the
after-recorded data is sent to the audio recording buffer 119 in
the form of a PES packet. The multiplexer 113 packs and sends the
PES packet to the recording buffer 114 such that the SCR of a pack
header and the PTS in a packet header are caused to be matched with
those in the original stream, respectively.
[0160] At the moment when the recording buffer 114 receives a pack
having a PTS exceeding a range of the CU that is being decoded, a
pack row in the recording buffer 114 is recorded onto the
after-recorded data file. The position of the CA to be recorded is
found in accordance with the PTS of the CU presently being decoded,
with reference to the continuous_area_table( ).
[0161] In cases where defect occurs during the recording of the CA,
the CA that is being recorded is discarded, and the CA is newly
recorded onto another region. A reason for this is that: the defect
causes a decrease in a recording region for the CA being recorded,
so that the region for the CA can no longer store data
corresponding to reproduction time of the relevant CU. In this
case, the placement_flag in the continuous_area_info( ) managing
the CA is changed to 0 so as to indicate that the CA does not exist
before the relevant CU. Also, in the file system management
information, an extent of the discarded CA is replaced with an
extent of the newly made CA.
[0162] This makes it possible to recognize in which part the CA and
the CU are not continuously recorded, by merely referring to the
placement_flag during the non-destructive editing and the
reproduction of the non-destructively edited result. On this
account, the user can be notified in advance that reproduction will
be highly likely to be interrupted during reproduction of the
aforesaid part. Further, the flag can be used in future for
re-positioning the CA and the CU, which are not continuously
recorded, to be continuously recorded.
Modified Example of Embodiment 1
[0163] In Embodiment 1, data is recorded onto the after-recording
data file, in accordance with the MPEG-2 format, as is the case
with the original stream file; however, data may be recorded onto
the after-recording data file, in compliance with the Elementary
Stream in which recording does not utilize such packing and
packeting. This cuts out the need of the re-packing after
extracting an AAU from a pack and replacing the extracted AAU, when
overwriting a part of the after-recorded data of the CA.
[0164] Further, in Embodiment 1, the CA stores the audio data, but
may store different types of data such as graphics data to be
superimposed on the video in the original stream.
[0165] In Embodiment 1, one AAU can be recorded over a plurality of
packs, but may be stored in one pack. With this, a part of the
after-recorded data in the CA can be rewritten merely by
overwriting a pack containing a relevant AAU.
[0166] In Embodiment 1, when occurrence of the defect in the CA is
detected during the after-recording, the CA is discarded and the
after-recorded data is recorded in another region. However, when
(i) the occurrence of the defect has been assumed and (ii) the size
of the CA is determined, upon initial picture recording, in
consideration of margin for such defect, and (iii) such defect is
detected, the after-recorded data may be recorded onto a position
coming after the position at which the defect occurred, in the CA.
This allows continuous recording of the CA and the CU.
[0167] For correlation (correspondence) between the CA and the CU
that are handled as different files, the respective head addresses
of the CU and the CA can be found in accordance with the time stamp
of the head of the data in the CU. However, any way of ensuring the
correlation may be used.
[0168] Embodiment 1 uses the MPEG-2 PS; however, similar effect can
be obtained by using the MPEG-2 TS.
Embodiment 2
[0169] Embodiment 2 of the present invention will be explained with
reference to FIG. 19.
[0170] Differences between Embodiment 1 and Embodiment 2 are as
follows. That is, in Embodiment 1, a plurality of sets of data to
be synchronously reproduced are continuously disposed in the
recording medium, and these sets of data are managed as different
files. In contrast, in Embodiment 2, the data sets are in the same
reproduction time-line, but are not simultaneously reproduced. In
Embodiment 2, reproduction is carried out by switching the data
sets between each other.
[0171] Specifically, Embodiment 2 utilizes the multi-angle function
in the DVD-Video, i.e., a function for switching images viewed from
a plurality of angles in the same time-line.
[0172] Note that a recording operation according to Embodiment 2 is
substantially the same as that of Embodiment 1, i.e., the relation
between the original stream and the after-recorded data that should
be synchronously reproduced in Embodiment 1 is merely replaced with
the relation between two types of the original streams that are in
the same time-line in Embodiment 2.
[0173] <File Structure>
[0174] The video/audio data are multiplexed in compliance with the
MPEG-2 PS standard, and are recorded onto different files in
accordance with angles. In an example shown in FIG. 19(a), first
angle data is recorded onto ANGL0001.M2P, and second angle data is
recorded onto ANGL0002.M2P.
[0175] <Layout in the Disc>
[0176] As shown in FIG. 19(b), the first angle data ANGL0001.M2P is
divided into partial data 2021, 2022, and 2023. Likewise, the
second angle data ANGL0002.M2P is divided into partial data 2011,
2012, and 2013. These sets of the partial data obtained by dividing
ANGL0001.M2P and ANGL0002.M2P are alternately positioned in a disc
2001. A method for determining a dividing scale is similar to a
method for positioning multi-angle data in case of the DVD-Video,
so that explanation thereof is omitted here.
[0177] This allows realization of angle switching response as fast
as the multi-angle switching response in the DVD-Video, and allows
each of the data files to be reproduced by a general MPEG-2 PS
compatible decoder.
Embodiment 3
[0178] Embodiment 3 of the present invention will be described with
reference to FIG. 21 through FIG. 28.
[0179] A difference between Embodiment 3 and Embodiment 1 is as
follows. That is, in Embodiment 1, the after-recording region is
managed by a single file (i.e., by the after-recording data file
(SHRP0001.PRE; see FIG. 4)). In contrast, in Embodiment 3, the file
for securing a vacant region is made separately from the file for
storing each set of AV data. Note that Embodiment 3 is similar to
Embodiment 1, so that explanation here is focused on a difference
therebetween.
[0180] <File/Directory Structure>
[0181] FIG. 21 illustrates a file/directory structure of Embodiment
3. The file/directory structure is obtained by adding, to the
file/directory structure (see FIG. 4) in Embodiment 1, (i) an
after-recording region reservation file (SHRP0001.RSV), (ii) an
after-recording data management information file (SHRP0001.PMI),
and (iii) a graphics file (SHRP0001.PNG).
[0182] The after-recording region reservation file (SHRP0001.RSV)
is a file for reserving an after-recording region. The
after-recording data management information file (SHRP0001.PMI) is
management information corresponding to the after-recording data
file. The graphics file (SHRP0001.PNG) is a file for storing
graphics data superimposed on video. Note that a program
information file (SHRP0001.PMG), an original stream management
information file (SHRP0001.OM1), and an original stream file
(SHRP0001.M2P) are the same as those in Embodiment 1,
respectively.
[0183] The after-recording region reservation file is made per
original stream file, and recording is carried out thereonto during
picture recording. The after-recording data management information
file is made per after-recording data file. The graphics file is a
file added when the non-destructive editing is carried out after
the picture recording, and is a file for storing images to be
superimposed on the video. Examples of the images include titles
and handwritten letters (characters). Such images are stored in
compliance with the PNG (Portable Network Graphics).
[0184] The after-recording data file (SHR0001.PRE) is not generated
until the after-recording is carried out, unlike Embodiment 1. In
other words, during the picture recording, the after-recording
region reservation file is recorded, in place of the
after-recording data file as in Embodiment 1.
[0185] <Structure of an AV Stream>
[0186] A structure of an AV stream is the same as the structure of
the AV stream, explained above with reference to FIG. 5, in
Embodiment 1.
[0187] <After-Recording Region Reservation File>
[0188] The after-recording region reservation file has the same
structure as the after-recording data file (see FIG. 6) in
Embodiment 1. That is, the after-recording region reservation file
is constituted by the integral number of continuous areas (CAs).
Each CA corresponds to one CU in the original stream file, and
secures a region for storing after-recorded data corresponding to a
relevant CU. Note that the CA here is merely in use for securing
the region, and is not AV data to be reproduced. For this reason,
the CA may contain any kinds of data.
[0189] <Layout in the Disc>
[0190] The following explains how data in the files of Embodiment 3
are positioned in the disc. FIGS. 22(a) and 22(b) illustrate
respective positions of the data of the files in cases where no
after-recording is carried out after the picture recording (in
other words, cases where the after-recording data file is not
made.) The original stream file (SHRP0001.M2P) and the
after-recording region reservation file (SHRP0001.RSV) correspond
to each other, and the CUs of the original stream file
(SHRP0001.M2P) and the CAs of the after-recording region
reservation file (SHRP0001.RSV) are recorded onto the optical disc
106 such that the CAs respectively come just before the
corresponding CUs (see FIG. 22(b)).
[0191] The following explains respective positions of the data of
the files including the after-recording region reservation file,
the after-recording data file, and the graphics file, i.e.,
positions of the data of these files after addition of audio and
graphics, with reference to FIGS. 23(a) and 23(b). FIG. 23(a)
illustrates respective structures of the graphics file
(SHRP0001.PNG) and the after-recording data file (SHRP0001.PRE),
each of which is additionally recorded onto the disc. The graphics
file stores graphics data IMG. The after-recording data file stores
after-recorded audio data PR#1, PR#2, and PR#3 which respectively
correspond to CU#n-1, CU#n, CU#n+1 in the original stream file
shown in FIG. 22(a).
[0192] The IMG and the PRs are positioned in the optical disc 106
as shown in FIG. 23(b). Specifically, in FIG. 22(b), the PR#1 is
positioned within a region secured by the CA#n-1, the PR#2 is
positioned within a region secured by the CA#n, and the PR#3 is
positioned within a region secured by the CA#n+1. The graphics data
IMG is positioned within a region secured by the CA#n+1.
[0193] Such Positioning of the IMG and the PRs within the
respective regions secured by the CAs causes reduction of
respective region sizes of the CA#n-1, the CA#n, and the CA#n+1.
The reduction is realized by changing extents in the file system
management information, these extents managing the respective
regions of the CAs.
[0194] Thus, such various types of data can be added with ease
after the picture recording, by introducing the after-recording
region reservation file for managing vacancy in the after-recording
regions. Further, the graphics data and the after-recording audio
data are stored in the different files, so that a different program
can refer merely to the graphics data. This allows more
flexibility.
[0195] <Formats Of Management Information Files>
[0196] A format of the original stream management information file
is the same as that of the original stream management information
file in Embodiment 1, so that explanation thereof is omitted here.
A format of the after-recording data management information file is
almost the same as that of the original stream management
information file in Embodiment 1, but p_attribute( ) and the
continuous_area_table( ) are not in the original stream management
information file unlike in Embodiment 1.
[0197] Next, FIG. 24 illustrates a structure of a program
information file. The program information file according to
Embodiment 3 includes: (i) subaudio_table( ) for managing the audio
data added after the picture recording; and (ii) graphics_table( )
for managing the graphics data added after the picture recording,
unlike the program information file (see FIG. 14) according to
Embodiment 1.
[0198] As shown in FIG. 25(a), the subaudio_table( ) is made up of
(i) number_of_subaudio for indicating the number of sets of the
audio data; and (ii) subaudio_info( ) for storing information about
the respective sets of the audio data. As shown in FIG. 25(b), the
subaudio_info( ) is made up of (i) SA_filename for storing a
filename of the after-recording data management information file
used for managing predetermined audio data; (ii) SA_flags for
managing various attributions of predetermined audio data; (iii)
SA_start_time for indicating reproduction start timing of the audio
data in the program; and (iv) SA_duration for indicating
reproduction duration time of the audio data in the program.
[0199] On the other hand, as shown in FIG. 26(a), the
graphics_table( ) is made up of (i) number_of graphics for
indicating the number of graphics files; and (ii) graphics_info( )
for storing information about each of the graphic files. As shown
in FIG. 26(b), the graphics_info( ) is made up of (i) gr_filename
for storing a filename of a predetermined graphics file; (ii)
gr_flags for managing various attributions of predetermined
graphics data; (iii) gr_start_time for indicating reproduction
start timing of the graphic data in the program; and (iv)
gr_duration for indicating reproduction duration time of the
graphic data in the program.
[0200] The SA_flags and the gr_flags have an identical structure,
and each of them includes a flag termed "interleave_flag" as shown
in FIG. 27(a). The interleave_flag is 1-bit information. See FIG.
27(b). When the interleave_flag is indicative of 0b, managed audio
data or a managed graphics file does not come just before a
relevant CU (that is to be reproduced in synchronism with the audio
data or the graphics file). In contrast, when the interleave_flag
is indicative of 1b, the managed audio data or the manage graphics
file comes just before the relevant CU (that is to be reproduced in
synchronism with the audio data or the graphics file). Reference to
the flag allows realization whether or not reproduction of a
non-destructive edited result possibly causes interruption in the
reproduction. In other words, when the flag is indicative of 0b,
the seeking of a CA is carried out, so that the reproduction is
highly likely to be interrupted.
[0201] <A Method for Determining a CU Scale>
[0202] A method for determining a CU scale is the same as the
method explained with reference to FIG. 7 and FIG. 8 in Embodiment
1.
[0203] <Processes During Recording>
[0204] Processes during recording are the same as the processes
explained with reference to FIG. 16 in Embodiment 1.
[0205] <Processes During Reproduction>
[0206] The following explains processes performed in response to
user's instruction for reproduction of the program having already
been subjected to the after-recording. Flow of the processes is
essentially the same as the flow explained with reference to the
flowchart of FIG. 17 in Embodiment 1, so that explanation for the
same processes explained above is omitted here. A difference
between the reproduction processes according to Embodiment 3 and
those according to Embodiment 1 lies in processes of reproducing
the scenes. For this reason, the following explanation addresses
the scene reproduction processes with reference to FIG. 28.
[0207] Firstly carried out is a search for video_unit_info( )
having the largest VU_PTS that is equal to or smaller than the
sc_start_PTS (S801), in reference to the video_unit_table( ) of the
original management information in the RAM 102. Note that order of
sets of the video_unit_info( ) in the video_unit_table( ) is
represented by VU numbers.
[0208] Next, a search is carried out for checking presence of a
graphic file and audio data, each of which is to be reproduced in
synchronism with a CU including a present VU (S802'). The search is
carried out with reference to the graphics_table( ) and the
subaudio_table( ) of the program information file. When such a
graphics file and such audio data exist, the graphics file is read
out, and corresponding audio data is read out in reference to the
audio data management information file managing the audio data
(S803').
[0209] Next, an address of the VU is found with reference to the
VU_PN of the video_unit_info( ) which corresponds to the present VU
number (S804). Based on the address, the VU is read out from the
original stream file (S805). Carried out next is judgment whether
or not the scene is over (S806). Specifically, when elapsed
reproduction time of the present scene is equal to or exceeds the
time specified by the sc_duration of the sceneinfo( ) the scene is
judged to be over.
[0210] When the reproduction of the scene is not over, numeral 1 is
added to the VU number (S807), and reference is made to the
first_unit_flag in the video_unit_info. In cases where the
first_unit_flag is indicative of 1, the VU managed by the
video_unit_info( ) is positioned in the head of the CU (S808).
Then, the check is carried out, in accordance with the
aforementioned steps, for presence of the graphics file and the
audio data which are to be used for the synchronized reproduction
(S809'). When such a graphics file and such audio data are found,
they are read out in accordance with the aforementioned steps
(S810').
[0211] <Processes During the after-Recording>
[0212] The following explains processes performed in response to
user's instruction for the after-recording. The processes during
the after-recording are performed by performing several processes
in addition to the aforesaid reproduction processes. For this
reason, the explanation here addresses only a difference
therebetween.
[0213] Firstly, presence of after-recording regions (regions for
the after-recording) in the recording medium is checked.
Specifically, the check is carried out with respect to the
continuous_area_info of the management information file about the
stream that is to be after-recorded, in order to find whether or
not each region secured by the after-recording region reservation
file has a size capable of storing the after-recorded data. When
the size of the region is sufficient, the after-recorded data is
recorded onto the region. When the size of the region is
insufficient, the after-recorded data is recorded onto a region
other than the region secured by the after-recording region
reservation file.
[0214] Next, the audio encoder 117 is launched concurrently with
start of reproduction. An encoded result of the after-recorded data
is sent to the audio recording buffer 119, in the form of PES
packets. The multiplexer 113 packs and sends the PES packets to the
recording buffer 114 such that a SCR of a pack header and a PTS in
a packet header correspond to those in the original stream,
respectively.
[0215] At the moment when the recording buffer 114 receives a pack
having a PTS exceeding a range of a CU that is presently being
decoded, the pack row in the recording buffer 114 is recorded onto
the after-recording data file. A position of the CA to be recorded
is found in accordance with the PTS of the CU presently being
decoded, with reference to the continuous_area_table( ). The
after-recorded data recorded onto the after-recording data file is
recorded onto the region secured by the CA.
[0216] At the moment of completion of the after-recording, the
followings are carried out. Firstly carried out is creation of the
after-recording data management file which corresponds to the
after-recording data file thus recorded. Upon the creation of the
after-recording data management file, a set of video_unit_info( )
is made per CU.
[0217] Next, an entry is added to the subaudio_table of the program
information file. In cases where the after-recorded data is
recorded onto the region secured by the after-recording region
reservation file, the interleave_flag of the SA_flags( ) is set at
1 upon the addition of the entry. In contrast, in cases where the
after-recorded data is not recorded onto the region, the
interleave_flag is set at 0 thereupon.
[0218] Further, the region storing the after-recorded data is ruled
out of scope of the file management of the after-recording region
reservation file. In other words, the size of the after-recording
region reservation file is reduced. Moreover, a CA_PN corresponding
to each entry in the continuous_area_table( ) is reduced by the
reduced size. With this, reference to the continuous_area_info( )
allows recognition of remained data storage space in each CA.
[0219] <Processes During Addition of the Graphics Data>
[0220] The following explains processes performed in response to
user's instruction for adding, to the video, the graphics data that
is to be superimposed on the video. Firstly, presence of a region
for storing the file containing the graphics data is checked.
Specifically, a check is carried out with respect to the
continuous_area_info( ) in the management information file about
the stream to which the graphics data is to be added, and a check
is carried out for presence of a region for storing the graphics
data in a CA corresponding to a CU containing a video frame from
which the graphic data to be superimposed starts to be
displayed.
[0221] When the graphics data can be recorded onto the CA, the
graphics data is recorded onto the region. As is the case with the
completion of the after-recording, the region storing the graphics
data is ruled out of the scope of the management by the
after-recording region reservation file. CA_PNs of entries of CAs
coming after the CA are reduced by the reduced size. Moreover, one
entry of the graphics_info( ) is added to the graphics_table( ) of
the program information file, and the interleave_flag of the
gr_flags( ) in the entry is set at 1. In this case, the graphics
data is so recorded onto the disc as to be positioned adjacent to
the video data to be reproduced together. With this, no seeking is
required for readout of the graphics data upon the video
reproduction. This restrains the interruption of the video
reproduction due to the seeking, and reduces power consumption.
[0222] In contrast, when the graphics data cannot be recorded in
the CA, the graphics data is recorded onto another region. One
entry of the graphicsinfo( ) is added to the graphics_table( ) of
the program information file, and the interleave_flag of the
gr_flags( ) in the entry is set at 0. By referring to the flag
during the reproduction, it is possible to notify, before the video
reproduction, the user that the video reproduction is possibly
interrupted.
Modified Example of Embodiment 3
[0223] In Embodiment 3, the graphics file and the after-recording
data file is additionally recorded after the picture recording;
however, the files may be recorded during the picture recording.
Also in this case, the graphics file and the after-recording data
file can be handled as independent files from the video file.
Moreover, the video file is a general MPEG-2 PS file, and the
seeking is not required for the synchronized reproduction.
[0224] In Embodiment 3, the graphics file is in compliance with the
PNG format, but may be in compliance with other file formats such
as the JPEG.
Embodiment 4
[0225] Embodiment 4 of the present invention will be explained with
reference to FIG. 29 and FIG. 30. Embodiment 4 is the same as
Embodiment 1 except the positioning of the data (file) in the disc
and the method for determining the CU scale. In other words,
Embodiment 4 provides variations of the positioning and the method
of Embodiment 1. For this reason, the following explanation
addresses the differences.
[0226] <File/Directory Structure>
[0227] A file/directory structure in Embodiment 4 is the same as
that in Embodiment 1, so that explanation thereof is omitted.
[0228] <Structure of AV Stream>
[0229] A difference between a structure of an AV stream in
Embodiment 4 and that in Embodiment 1 lies in only that: the CUs
may not be continuously recorded in the present embodiment.
[0230] <After-Recording Data File>
[0231] An after-recording data file in Embodiment 4 is the same as
that in Embodiment 1, so that explanation thereof is omitted.
[0232] <Layout in the Disc>
[0233] The following explains how respective data of an original
stream file and an after-recording data file are positioned in the
disc, with reference to FIG. 29. FIG. 29(a) illustrates the
original stream file (SHRP0001.M2P) and the after-recording data
file (SHRP0001.PRE) which correspond to each other. Essentially,
the respective data of the original stream file and the
after-recording data file are recorded onto the optical disc 106
such that a CA comes just before a corresponding CU, like in
Embodiment 1. However, the CU may be divided, unlike Embodiment 1.
FIG. 29(b) illustrates an example in which a CU#n-1 and a CU#n are
provided. However, it should be noted that the CA must not be
divided. Note also that a total of reproduction time of VUs in one
continuous region must be equal to or longer than reproduction time
of the CU.
[0234] Such division of the CU allows a vacant region to be
effectively used. For example, see a case where CUs each
corresponding to 16 seconds are respectively recorded onto
continuous vacant regions that are in the optical disc 106 and that
correspond to 20 seconds in total. In cases where each CU is not
divided, the vacant regions used for the recording correspond to
only 16 seconds, and the remaining corresponding to 4 seconds is
left unused. On the contrary, in cases where the CU is divided, the
vacant regions corresponding to 20 seconds can be fully used.
[0235] <A Method for Determining a CU Scale>
[0236] The following explains a method for determining reproduction
time of a CU, with reference to FIG. 30. As is the case with
Embodiment 1, in the method, the reproduction time of the CU is
determined such that the seamless reproduction does not fail when
the after-recording is carried out with the use of (i) a device
(reference device model) set as a reference for ensuring
compatibility between devices; and (ii) an after-recording algorism
(reference after-recording algorism) set as a reference
therefor.
[0237] The reference device model is the same as that of Embodiment
1, so that explanation thereof is omitted.
[0238] The reference after-recording algorism can be described as
follows:
[0239] (a) Essentially, upon completion of readout of a present CU,
recording of a CA is carried out.
[0240] (b) In cases where an end of a CU coming after the
presently-readout CU is stored in a different continuous region,
recording of the CA is postponed until readout of the subsequent CU
is over.
[0241] FIGS. 30(a) and 30(b) illustrate examples of the reference
after-recording algorism. FIG. 30(a) illustrates an example of the
above operation (a). Note that the numbers (1) through (8) in FIG.
30 respectively correspond to the following numbers (1) through
(8).
[0242] (1) Read out an n-th CU termed "CU#N". (2) Move the pickup
to a CA#M that should be recorded next, upon completion of encoding
of after-recorded data corresponding to the CA#M. (3) Record the
after-recorded data onto the CA#M. (4) Move the pickup to a CU#N+1.
(5) Read out the CU#N+1. (6) Move the pickup to a CA#M+1 that
should be recorded next, upon completion of encoding of
after-recorded data corresponding to the CA#M+1. (7) Record the
after-recorded data onto the CA#M. (8) Move the pickup to a
CU#N+2.
[0243] See the case of FIG. 30(b) illustrating an example of the
above operation (b): (1) Read out the CU#N, but skip the recording
of the CA immediately after the readout of the CU#N, and then read
out a former portion of a CU#N+1 coming after the CN#N. This is
because the CU#N and the former portion of the CU#N+1 are
positioned in the same continuous region, and because an end of the
CU#N+1 is positioned in a different continuous region. (2) Move the
pickup to a CA#M upon completion of reading out the CU#N+1 until
the end of the continuous region. (3) Record the after-recorded
data onto the CA#M. (4) Move the pickup to a latter portion of the
CU#N+1.
[0244] With such an algorism, a jump between the continuous regions
and a jump for the recording of the CA can be carried out at a time
even in the case where the CU is divided. This minimizes the
interruption of the data readout due to such jumps, with the result
that each continuous region can have a smaller length and each CU
and each CA have smaller scales. On this account, the vacant
regions in the disc can be effectively used.
[0245] In the case where the after-recording is carried out with
the use of the aforesaid reference device model and the aforesaid
reference after-recording, the after-recording buffer 504 is surely
free from the overflow, and the track buffer 502 is surely free
from the underflow, as long as the following condition is
satisfied.
[0246] That is, the condition is satisfaction of Formula (1)
described in Embodiment 1. Note that symbols in Embodiment 4 have
the same meanings as the symbols in Embodiment 1, respectively, as
long as specific explanation of such symbols is not made.
[0247] As is the case with Embodiment 1, Tw(i) in Formula (1) is
represented by Formula (4). However, Tr(i) therein is represented
by the following Formula (8):
Tr(i)=Te(i).times.Ro/Rs+Te(i).times.Ra/Rs (8)
Formula (8) is a formula obtained by removing, from Formula (3), Ta
indicating the jump.
[0248] A reason for removing Ta indicating the jump is as follows.
That is, in Embodiment 4, the jump during the readout of the CU is
carried out at the time of recording the CA, so that the jump
during the readout of the CU is regarded as the jump during the
recording of the CA. This allows reduction of respective scales
that the CU and the continuous region finally have.
[0249] When Formula (8) and Formula (4) are substituted in Formula
(1) to solve for Te(i), a condition of Te(i) ensuring the real-time
after-recording is obtained as the following Formula (9):
Te ( i ) .gtoreq. 2 Ta .times. Rs Rs - Ro - 2 Ra ? indicates text
missing or illegible when filed ? ##EQU00002##
[0250] Accordingly, the CU reproduction time lower limit value
Temin that ensures the after-recording is represented by the
following formula (10):
Te min = 2 Ta .times. Rs Rs - Ro - 2 Ra ? indicates text missing or
illegible when filed ? ##EQU00003##
[0251] A CU reproduction time upper limit value Temax is so set as
to satisfy the following Formula (11):
Te max = 2 Ta .times. Rs Rs - Ro - 2 Ra + Tv max ? indicates text
missing or illegible when filed ( 1 ? ##EQU00004##
where Tvmax indicates maximum reproduction time of the VU.
[0252] The setting of the upper limitation value of the CU
reproduction time is carried out so as to allow for estimation of
maximum retardation memory amount required for the synchronized
reproduction of the after-recorded audio and the normal audio, and
so as to ensure reproduction compatibility. Note that, in
Embodiment 4, the multiplexing interval lower limit value Temin is
set according to the audio bit rate Ra and the video bit rate Rv;
however, the lower limit value may be constant at any value as long
as the lower limit value is based on the maximum bit rate.
[0253] Moreover, reproduction time of the VU in the stream may be
constant or variable as long as the reproduction time of the CU is
in accordance with the aforementioned restriction.
[0254] <Required Buffer Memory Amount>
[0255] In the present embodiment, a volume required, during the
after-recording, in the track buffer 502 is determined based on the
following idea. That is, in Embodiment 4, the largest volume is
required in cases where the recording of the after-recorded data is
serially carried out onto the CAs. Specifically, the largest volume
is required in cases where each of the CUs is divided in a portion
just before an end of the CU. In other words, the largest volume is
required in cases where the CU is separately stored in two
continuous regions, and where most data in the CU is stored in a
former one of the continuous regions.
[0256] In this case, according to the aforesaid reference
after-recording algorism, the after-recording is carried out in the
following manner. That is, the readout of the CU continues until a
portion just before the end of the CU, and then the pickup moves to
the CA so as to record the after-recorded data. Then, the pickup
moves back so as to read out the slight amount of the remained data
in the CU. Immediately after the readout, the pickup moves to the
next CA to record the after-recorded data, and moves back to read
out the CA. Such an operation requires a volume that allows for
reproduction continuously lasting over a period corresponding to
(i) two recording operations of the after-recording data with
respect to the CAs; and (ii) the readout operation of one CA. A
specific way of securing such a volume Bpb of the track buffer
memory 502 is to be in accordance with the following Formula
(12):
Bpb=(2.times.(2.times.Ta+Temax.times.Ra/Rs)+Temax.times.Ra/Rs).times.Ro
(12)
[0257] <Formats of the Management Information Files>
[0258] Formats of the management information files in Embodiment 4
are the same as those in Embodiment 1, respectively, so that
explanation thereof is omitted here.
[0259] <Processes During Recording>
[0260] Processes during recording in Embodiment 4 are the same as
those in Embodiment 1, except that Embodiment 4 is free from the
restriction in continuously recording the CUs onto the disc.
[0261] <Processes During Reproduction>
[0262] Processes during reproduction in Embodiment 1 are the same
as those in Embodiment 4, so that explanation thereof is omitted
here.
[0263] <Processes During after-Recording>
[0264] Processes during after-recording in Embodiment 4 are the
same as those in Embodiment 1, except that the algorism shown in
FIG. 30 is utilized during the after-recording. For this reason,
explanation thereof is omitted here.
Modified example of Embodiment 4
[0265] Embodiment 4 is explained as a variation of Embodiment 1;
however, Embodiment 4 is applicable to (i) a case where the
after-recording region reservation file is used as in Embodiment 3,
and (ii) a case where one file deals with the stream data and the
after-recorded data as in Japanese Laid-Open Patent Publication
Tokukai 2001-43616. In other words, essence of the invention
disclosed by the present embodiment lies in (i) the respective
physical positioning of the after-recording region and the
initially recorded video data; and (ii) the model setting for
setting the parameters for the positioning.
INDUSTRIAL APPLICABILITY
[0266] The present invention is applicable to a digital
recording/reproducing apparatus (video disc recorder) that has an
after-recording function and that uses disc (disk) recording medium
such as a DVD and a hard disk.
* * * * *