DESCRIPTION
RECORDING APPARATUS, METHOD FOR RECORDING, REPRODUCING
APPARATUS, METHOD FOR REPRODUCTION, PROGRAM, AND RECORDING
MEDIUM
Technical Field
The present invention relates to a recording apparatus,
a method for recording, a reproducing apparatus, a method for
reproduction, a program, and a recording medium for recording
a content file and an index file for managing the content file
on a recording medium or for reproducing the content file from
the recording medium.
Specifically, the invention relates to a recording
apparatus and so on in which the index file has a
decode-information storage area for collectively storing
information on the decoding of content files recorded on a
recording medium, and in which the entries of the index file
corresponding to the content files and assigned attribute
information of the corresponding content files have pointer
information indicative of corresponding decode information in
the decode-information storage area so that detailed decode
information of the content files can be recorded without a
significant increase in the size of the index file, thereby
allowing accurate determination whether the content files can
be reproduced.
Background Art
Methods for easily finding a desired file from a large
number of files recorded on a mass-storage recording medium
by using an index file are proposed in Patent Documents 1, 2,
3, and so on.
Index files are for managing content files and have a
set of attribute information of the content files. The
attribute information of a content file includes thumbnail
picture data, title text data, the date of photo shooting, codec
information, and face information (face size, face position,
and digitized face score).
As shown in Fig. 9, the index file includes a text file
(or a meta-data file) FTX, a thumbnail picture file FTH, and
a property file FP. The attribute information of the content
file is divided into the text file FTX, the thumbnail picture
file FTH, and the property file FP.
However, some types of content file have no attribute
information disposed in the text file FTX and the thumbnail
picture file FTH, so that they sometimes have no entry. Fig.
9 shows a case in which each content file has attribute
information for the text file FTX, the thumbnail picture file
FTH, and the property file FP.
Here the index file composed of a property file, a
thumbnail picture file, and a text file (or a meta-data file)
is particularly referred to as an AV-Index file.
The text file FTX manages text information (meta-data
for a meta-data file) . The thumbnail picture file FTH manages
thumbnail picture data. The property file FP manages
attribute information (basic attribute information) except
attribute information on the text file FTX or the thumbnail
picture file FTH, and also manages information on the
connection among the slots of other files.
The property file FP has a header indicative of its
attribute at its head. In contrast, the text file FTX and the
thumbnail picture file FTH have no header at their heads.
However, the text file FTX and the thumbnail picture file FTH
sometimes have a header indicative of their attribute at their
heads, as with the property file FP. Following the header,
the content files have continuous entries including their
attribute information (a property entry #1, a property entry
#2, , a thumbnail picture entry #1, a thumbnail picture entry
#2, , or a text entry #1, a text entry #2, ) .
The entries of the text file FTX are assigned data
indicative of character strings of disc titles or the titles
of the content files. The entries of the thumbnail picture
file FTH are assigned thumbnail picture data indicative of disc
titles or the content of the content files.
The entries of the text file FTX and the thumbnail picture
file FTH each include fixed-length slots. The number of slots
of each entry is one or more according to the amount of attribute
information assigned to the entry. Since the type of attribute
information depends on the type of content file, no entry is
sometimes provided, as described above.
The entries of the property file FP are assigned data
indicative of the disc title or the attribute of the content
files, respectively. The property file FP includes
fixed-length slots as with the text file FTX and the thumbnail
picture file FTH. The property file FP always has entries
corresponding to the content files even if the type of the
content files varies.
The entries of the property file FP have management
information (relation information indicated by the arrows in
Fig. 9) that specifies the corresponding entries of the text
file FTX and the thumbnail picture file FTH as management
information indicative of the relation with other entries.
The entries of the property file FP each including a plurality
of slots have management information that specifies the slots
following the previous slots. The entries of the property file
FP also have information that specifies a corresponding content
file.
The index file has the above structure. Therefore, for
example, the titles of the content files recorded on a recording
medium 2 can be displayed in list form by reproducing the data
row recorded on the text file FTX. Moreover, for example, the
thumbnail pictures of the content files recorded on the
recording medium 2 can be displayed in list form by reproducing
the data row recorded on the thumbnail picture file FTX.
The index file can be defined not only for the existent
content files but also for virtual folders by the text file
FTX, the thumbnail picture file FTH, and the property file FP.
The entries of the property file FP also have information that
defines the hierarchical structure of the content files and
the virtual folders.
Fig. 10 shows an example of the correspondence between
the property file and the content files and virtual folders.
In this example, a virtual folder with the date of picture
shooting of "Date A" and a virtual folder with the date of
picture shooting of "Date B" are present on the same level;
a content file of "MPEG2PS-1" is present on a level lower than
the virtual folder of "Date A" ; and content files of "MPEG2PS-2"
and "MPEG2PS-3" are present on a level lower than the virtual
folder of "Date B".
In correspondence with such a hierarchical structure,
the property file includes a file entry #1, a folder entry #4,
a file entry #6, a folder entry #8, and a folder entry #9, as
shown in Fig. 10. The number of each entry is the number of
the first slot thereof. In the example illustrated, the number
of each entry is set at the smallest number of the slots of
the entry for convenience.
The file entries #1, #6, and #9 manage the content files
of "MPEG2PS-1", "MPEG2PS-2", and "MPEG2PS-3", respectively,
while the folder entries #4 and #8 manage the virtual folders
of "Date A" and "Date B", respectively.
Recording media such as optical discs are sometimes
written various content files when loaded in various devices.
In this case, it is sometimes difficult for a device with low
decoding performance to decode any of the various-format
content files recorded on the recording media. In that case,
when such hard-to-decode content files are displayed in the
list of thumbnail pictures, the ease-of-use is decreased.
The above-described Patent Document 2 discloses a method
of recording decode information of the content files stored
in a recording medium in advance on the corresponding entries
of the index file and then determining whether the content file
can be decoded on the basis of the record. Patent Document
2 also discloses a method for recording the decode information
in coded form.
Patent Document 1: JP-A-2004-227630
Patent Document 2: JP-A-2004-227633
Patent Document 3: JP-A-2005-115815
Disclosure of the Invention
Problems that the Invention is to Solve
There is various decode information. Examples of
information on the decoding of video data include the type of
codec, the profile type of codec, the level, the bit rate, and
the screen size. Examples of information on the decoding of
audio data include the type of codec, the profile type of codec,
the level, the bit rate, and the sampling frequency.
When such information is necessary for decoding, if 4
bytes are assigned to one piece of information, at least 32
bytes are needed for one content. Accordingly, when many
content files are registered in an index file, the size of the
index file increases significantly.
The decode information per content can be set at about
4 bytes by coding the decode information. However, this makes
the decode information extremely rough because the combination
of the above information is expressed in limited codes (e.g.,
4 bytes). Moreover, when a new type of codec, profile, bit
rate, or the like is added, it is difficult for some assigned
codes to assign appropriate codes thereto. Furthermore, since
it is impossible to recognize the meaning of a new assigned
code with a device manufactured before the new code is assigned,
the device will determine that the content file cannot be
reproduced despite its reproducing capability.
Accordingly, it is an object of the present invention
to allow detailed recording of decode information of content
files to some extent without a major increase in the size of
the index file, thereby permitting accurate determination
whether the content files can be reproduced.
Means for Solving the Problems
A concept of the invention is a recording apparatus for
recording a content file including at least encoded video data
or encoded audio data and an index file for managing the content
file and including a set of attribute information of the content
file on a recording medium, the recording apparatus comprising:
a content-file recording section for recording the
content file on the recording medium; and
an index-file updating section for updating the index
file so as to register a desired content file when the content
file is recorded on the recording medium by the content-file
recording section; wherein
the index file includes a predetermined number of entries
corresponding to the content file recorded on the recording
medium and assigned the attribute information of the
corresponding content file and a decode-information storage
area for storing decode information of the content file;
the predetermined number of entries have pointer
information indicative of decode information of the
corresponding content file from among the decode information
stored in the decode-information storage area; and
the index-file updating section adds an entry to the
index file when updating the index file so as to register the
content file, the entry being corresponding to the content file
and having pointer information indicative of the decode
information of the content file stored in the
decode-information storage area.
A concept of the invention is a reproducing apparatus
for reproducing a desired content file from a recording medium
on which a content file including at least encoded video data
or encoded audio data and an index file for managing the content
file and including a set of attribute information of the content
file are recorded, wherein
the index file includes a predetermined number of entries
corresponding to the content file recorded on the recording
medium and assigned the attribute information of the
corresponding content file and a decode-information storage
area for storing all the decode information of the content file;
and
the predetermined number of entries have pointer
information indicative of decode information of the
corresponding content file from among the decode information
stored in the decode-information storage area; and wherein the
reproducing apparatus comprises:
a content-file reproducing section for reproducing a
desired content file from the recording medium to acquire video
data or audio data contained in the content file; and
an index-file reproducing section for reproducing the
index file from the recording medium;
wherein the content-file reproducing section determines
whether the content file can be reproduced with reference to
the decode information on the basis of the pointer information.
According to the invention, at least a content file and
an index file are recorded on a recording medium. The index
file manages the content file and includes a set of attribute
information of the content file. The content-file recording
section records the content file on the recording medium.
When a content file is recorded on a recording medium
by the content-file recording section, the index file recorded
on the recording medium is updated by the index-file updating
section. Since the index file is updated, the index file stored
in the recording medium and the content file are agreed with
each other.
The index file includes entries corresponding to the
content file recorded on the recording medium and a
decode-information storage area in which all the decode
information of the content file is stored. The entries are
assigned the attribute information of the corresponding
content file, and have pointer information indicative of decode
information of the corresponding content file from among the
decode information stored in the decode-information storage
area.
When a desired content file is recorded on the recording
medium, the index file is updated so that the content file is
registered. At that time, an entry corresponding to the
content file is added to the index file. The entry is given
pointer information indicative of the decode information of
the corresponding content file.
Thus, all the decode information of the content files
recorded on the recording medium is stored in the
decode-information storage area of the index file; and the
entries of the index file corresponding to the content file
have pointer information indicative of the corresponding
decode information in the decode-information storage area.
This prevents duplicate recording of the same decode
information on the index file, and allows decode information
to be recorded without being coded. Therefore, detailed
decode information of the content file can be recorded without
a significant increase in the size of the index file.
For example, when updating the index file so as to
register the desired content file, the index-file updating
section adds the decode information of the content file to the
decode-information storage area when the decode information
of the content file is not stored in the decode-information
storage area. Since new decode information can thus be added
to the decode-information storage area, the invention is also
suitable for recording a content file that is not stored in
the decode-information storage area and that does not
correspond to the decode information on a recording medium.
For example, it is also possible that when decode
information is stored in the decode-information storage area,
the decode information being different in bit rate or frame
rate from the decode information of the desired content file
and having a bit rate or a frame rate that is obtained by rounding
up a predetermined digit of the bit rate or the frame rate of
the decode information of the content file, the index-file
updating section determines that decode information of the
content file is stored in the decode-information storage area.
This allows all the decode information to be expressed
collectively, thus reducing the size of the index file.
According to the invention, a desired content file is
selectively reproduced from a recording medium by the
content-file reproducing section. In this case, it is
determined whether the content file can be reproduced on the
basis of the decode information in the decode-information
storage area which is indicated by the pointer information of
the entry of the index file corresponding to the content file,
the index file being reproduced by the index-file reproducing
section. Thus, a determination of reproducibility can be made
on the basis of the decode information itself corresponding
to the content file, allowing accurate determination whether
the content file can be reproduced.
For example, the content-file reproducing section
determines whether the content file can be reproduced for each
decode information stored in the decode-information storage
area of the index file, and stores the result of determination
in a predetermined storage area in association with the pointer
information. When reproducing a desired content file from the
recording medium, the content-file reproducing section
determines whether the content file can be reproduced on the
basis of the determination result stored in the predetermined
storage area in association with the pointer information of
the entry of the index file corresponding to the content file.
In this case the determination stored in a predetermined
storage area can be used, allowing high-speed determination
whether the content file can be reproduced.
Advantage of the Invention
According to the invention, the index file has a
decode-information storage area for storing all the decode
information of the content file stored in a recording medium;
the index file also has entries corresponding to the content
file and assigned attribute information of the corresponding
content file, the entries having pointer information
indicative of decode information of the decode-information
storage area. This allows detailed decode information of the
content file to be recorded without a significant increase in
the size of the index file, thereby permitting accurate
determination whether the content file can be reproduced.
Brief Description of the Drawings
Fig. 1 is a block diagram showing the structure of an
optical disk unit;
Fig. 2 is a diagram showing that a property file has a
system information entry and a plurality of file entries;
Fig. 3 is a diagram showing the structure of a profile
data list of a system information entry.
Fig. 4 is a diagram showing the structure of an AV profile
entry assigned to the profile data list;
Fig. 5 is a diagram showing the structure of a video
profile entry of the AV profile entry;
Fig. 6 is a diagram of the structure of an audio profile
entry of the AV profile entry;
Fig. 7 is a flowchart for the procedure of a system control
microcomputer in a content-file recording mode;
Fig. 8 is a flowchart for the procedure of the system
control microcomputer in a content-file reproducing mode;
Fig. 9 is a diagram for explaining a text file, a thumbnail
picture file, and a property file of an index file; and
Fig. 10 is a diagram of an example of the correspondence
among a property file, virtual files, and content files.
14
Description of Reference Numerals and Signs
1: optical disk unit, 2: optical disk, 11: video encoder,
12: audio encoder, 13: video decoder, 14: audio decoder, 15:
file generator, 16: file decoder, 17, 20: memory, 18: memory
controller, 19: system control microcomputer, 21:
error-collection encoder/decoder, 22: drive control
microcomputer, 23: modem, 24: magnetic-field modulation
driver, 26: operating section
Best Mode for Carrying Out the Invention
An embodiment of the invention will be described. Fig.
1 shows the structure of an optical disk unit 1 according to
the embodiment.
The optical disk unit 1 acquires the video signal and
the audio signal of an object with an image pickup means and
an audio acquisition means (not shown), respectively, and
records the content of the video signal and the audio signal
on an optical disk 2 as a content file. The optical disk unit
1 reproduces the content file recorded on the optical disk 2,
and outputs it with a display means of a liquid-crystal display
panel and an audio output means of a speaker or to an external
device. The optical disk unit 1 encodes the video signal and
the audio signal according to the Moving Picture Experts Group
(MPEG) format, and then records them on the optical disk 2 in
a specified file format.
The optical disk unit 1 includes the optical disk 2, a
video encoder 11, an audio encoder 12, a video decoder 13, an
audio decoder 14, a file generator 15, a file decoder 16, a
memory 17, a memory controller 18, a system control
microcomputer (hereinafter, referred to as "a system control
microcomputer") 19, a memory 20, an error-collection
encoder/decoder 21, a drive control microcomputer
(hereinafter, referred to as "a drive control microcomputer")
22, a modem 23, a magnetic-field modulation driver 24, an
operating section 26, a servo circuit 30, a spindle motor 31,
a magnetic field head 32 , and an optical pickup 33 . The optical
disk 2 is a recording medium.
The video encoder 11 converts the video signal resulting
from video shooting from analog to digital to generate video
data, encodes the video data according to MPEG format, and
output the elementary stream of the video data. The audio
encoder 12 converts an audio signal on the video shooting from
analog to digital to generate audio data, encodes the audio
data according to the MPEG format, and outputs the elementary
stream of the audio data.
In the recording mode, the file generator 15 multiplexes
the elementary streams output from the video encoder 11 and
the audio encoder 12 to generate a content file in a specified
file format under the control of the system control
microcomputer 19.
The memory controller 18 switches its operation between
recording and reproduction by the control of the system control
microcomputer 19. In the recording mode, the memory
controller 18 sequentially records the data row of the content
files output from the file generator 15 and various data output
from the system control microcomputer 19 on the memory 17 and
temporarily stores them, and outputs the stored data according
to the following process of the error-collection
encoder/decoder 21. In the reproducing mode, the memory
controller 18 sequentially records the data output from the
error-collection encoder/decoder 21 on the memory 17 and
temporarily stores them, and outputs the data row of the content
files to the file decoder 16, and outputs the various data to
the system control microcomputer 19.
The error-collection encoder/decoder 21 switches its
operation between recording and reproduction by the control
of the system control microcomputer 19 . In the recording mode,
the error-collection encoder/decoder 21 temporarily stores
the data output from the memory controller 18 in the memory
20, and adds an error-correcting code thereto. The
error-collection encoder/decoder 21 reads the data stored in
the memory 20 in a predetermined order in the recording mode,
and outputs the data subjected to interleave to the modem 23.
In the reproduction mode, the error-collection
encoder/decoder 21 temporarily stores the data output from the
modem 23 in the memory 20 in a predetermined order to thereby
perform an interleaving process and error correction with the
error-correcting code added during recording. In the
reproduction mode, the error-collection encoder/decoder 21
reads the data stored in the memory 20 in the same order as
that in recording, and outputs it to the memory controller 18.
The modem 23 switches its operation between recording
and reproduction by the control of the system control
microcomputer 19 . In the recording mode, the modem 23 converts
the data output from the error-collection encoder/decoder 21
to a serial data row, modulates it, and outputs it to the
magnetic-field modulation driver 24 or the optical pickup 33.
In the reproduction mode, the modem 23 reproduces a clock from
the reproducing signal output from the optical pickup 33, and
decides the binary level of the reproducing signal with
reference to the clock to demodulate it. The modem 23 thus
acquires reproduced data corresponding to the serial data row
generated in the recording mode, and outputs the reproduced
data to the error-collection encoder/decoder 21.
When the optical disk 2 is a magnetooptical disk, in the
recording mode, the magnetic-field modulation driver 24 drives
the magnetic field head 32 according to the signal output from
the modem 23 by the control of the system control microcomputer
19 . The magnetic field head 32 is opposed to the optical pickup
33 with the optical disk 2 therebetween, and applies a
modulation magnetic field according to the data output from
the modem 23 to the position to be irradiated with the laser
beam from the optical pickup 33 . Accordingly, when the optical
disk 2 is a magnetooptical disk, the optical disk unit 1 records
content files etc. on the optical disk 2 by the method of
thermomagnetic recording.
The optical disk 2 is a rewritable optical disk such as
a magneto optical disk (MO) or a phase-change disk. The spindle
motor 31 rotates the optical disk 2 by the control of the servo
circuit 30 under the condition of constant linear velocity
(CLV) , constant angle velocity (CAV) , or zone constant velocity
(ZCLV) depending on the type.
The servo circuit 30 controls the operation of the
spindle motor 31 according to various signals output from the
optical pickup 33. The servo circuit 30 also controls the
tracking operation and the focusing operation of the optical
pickup 33 according to various signals output from the optical
pickup 33, and the seek operation of the optical pickup 33 and
the magnetic field head 32, and furthermore executes a focus
searching operation and so on.
The drive control microcomputer 22 controls the seek
operation and so on of the servo circuit 30 according to the
instruction from the system control microcomputer 19.
The optical pickup 33 applies a laser beam to the optical
disk 2 and receives its returned light with a photoreceptor,
and calculates the result of photoreception of the
photoreceptor to output various control signals, and also
outputs a reproducing signal whose level varies according to
the bit string or mark string formed on the optical disk 2.
The optical pickup 33 switches its operation by the
control of the system control microcomputer 19. When the
optical disk 2 is a magnetooptical disk, the optical pickup
33 intermittently increases the amount of the laser beam
applied to the optical disk 2 in the recording mode. In this
case, the optical disk unit 1 records content files on the
optical disk 2 by a pulse train method. When the optical disk
2 is a phase change disk, the optical pickup 33 increases the
amount of the laser beam to be applied to the optical disk 2
from that for reproduction to that for writing operation
according to the data output from the modem 23. In this case,
the optical disk unit 1 records content files on the optical
disk 2 by the method of thermography.
The file decoder 16 inputs the data of the content files
output from the memory controller 18, and divides the data into
the elementary streams of video data and audio data, and outputs
them. The video decoder 13 extends the elementary stream of
the video data output from the file decoder 16, and outputs
it to a display means or an external device (not shown) . The
audio decoder 14 extends the elementary stream of the audio
data output from the file decoder 16, and outputs it to an audio
output means or an external device (not shown).
The operating section 26 includes various operators and
a touch panel on the liquid-crystal display panel in the optical
disk unit 1, which notifies the system control microcomputer
19 of various operations by the user.
The system control microcomputer 19 is for controlling
the entire operation of the optical disk unit 1. The system
control microcomputer 19 controls the entire operation by
executing a predetermined processing program stored in a memory
(not shown) . In this embodiment, the processing program for
the system control microcomputer 19 is installed in the optical
disk unit 1 in advance. Alternatively, in place of the
pre-installation, this processing program may either be
downloaded via a network such as the Internet or recorded on
a recording medium such as an optical disk, a magnetic disk,
or a memory card.
For example, upon detection of the loading of the optical
disk 2, the system control microcomputer 19 makes the optical
pickup 33 seek around the innermost circumference of the
optical disk 2 to reproduce the management information of the
file management system of the optical disk 2 by the execution
of the processing program. The system control microcomputer
19 acquires the reproduced management information from the
memory controller 18, and stores it in a built-in memory.
The system control microcomputer 19 finds the addresses
of the files recorded on the optical disk 2 and free space on
the basis of the management information stored in the built-in
memory. The system control microcomputer 19 reproduces the
index file recorded on the optical disk 2 according to the
management-information search result, and presents the
various content files recorded on the optical disk 2 to receive
user's operation. The index file reproduced from the optical
disk 2 is stored in the built-in memory of the system control
microcomputer 1 or in the memory 17. In this embodiment, the
index file is stored in the built-in memory.
When the user gives an instruction to record an image
pickup result, the system control microcomputer 19 detects free
space according to the management information stored in the
built-in memory, makes the optical pickup 33 seek in the free
space, and records the picture content file on the optical disk
2.
The system control microcomputer 19 updates the
management information stored in the built-in memory according
to the record of the content file, and updates the management
information recorded on the optical disk 2 according to the
updated management information at the time of unloading the
optical disk 2 . The system control microcomputer 19 executes
the update of the management information by outputting the
updated management information stored in the built-in memory
to the error-collection encoder/decoder 21 via the memory
controller 18.
When recording the content file on the optical disk 2,
the system control microcomputer 19 outputs various
information necessary for generating the content file to the
file generator 15. The system control microcomputer 19
acquires information necessary for generating the index file
via the video encoder 11, the audio encoder 12, and the file
generator 15 . The system control microcomputer 19 updates the
index file stored in the built-in memory in correspondence with
the recording of the content file on the optical disk 2 on the
basis of the acquired information and the information output
to the file generator 15, and updates the index file recorded
on the optical disk 2 according to the updated data of the index
file.
In this case, the system control microcomputer 19 updates
the index file in correspondence with the recording of the
content file stored in the built-in memory by adding the entries
corresponding to the content file recorded on the optical disk
2 to the index file.
The operation of the optical disk unit 1 shown in Fig.
1 will be briefly described.
When the optical disk 2 is loaded after the power of the
apparatus main body is turned on or when the power is turned
on after the optical disk 2 has been loaded, the optical pickup
33 is controlled so as to seek around the innermost
circumference of the optical disk 2, and the management
information of the file management system is reproduced from
the optical disk 2. The management information is stored in
the memory built in the system control microcomputer 19 via
the memory controller 18. The system control microcomputer
19 finds the addresses of the files recorded on the optical
disk 2 and free space on the basis of the management information
stored in the built-in memory. After the management
information is acquired, an index file is reproduced from the
optical disk 2 on the basis of the management-information
search result. The index file is stored in the memory built
in the system control microcomputer 19.
The operation of recording the picture content file on
the optical disk 2 will be described.
The video data acquired by the image pickup means and
the audio data acquired by the audio acquisition means are
encoded by the video encoder 11 and the audio encoder 12,
respectively, and supplied to the file generator 15. The file
generator 15 multiplexes the elementary stream of the video
data acquired by the video encoder 11 and the elementary stream
of the audio data acquired by the audio encoder 12 to generate
a content file in a predetermined file format.
The content file is recorded on a free space of the optical
disk 2 via the recording system configured by the memory
controller 18, the error-collection encoder/decoder 21, the
modem 23, the magnetic-field modulation driver 24, and the
optical pickup 33.
In parallel with the content-file recording process,
thumbnail picture data is generated from the video data. The
system control microcomputer 19 updates the data of the index
file stored in the built-in memory on the basis of the attribute
information of the content file to be recorded such as the
thumbnail picture data and the file name.
As described above, after the content file is recorded
on the optical disk 2, the index file stored in the optical
disk 2 is updated according to the data of the index file updated
in correspondence with the recording of the content file, the
data being stored in the built-in memory of the system control
microcomputer 19.
The index file includes entries corresponding to the
content files recorded on the optical disk 2 and a
decode-information storage area in which all the decode
information of the content files is stored. The entries are
assigned attribute information on the corresponding content
files and have pointer information indicative of the decode
information of the corresponding content files of the decode
information stored in the decode-information storage area.
When a content file is recorded on the optical disk 2,
the index file is updated so as to register the specified
content file. At that time, an entry corresponding to the
specified content file is added to the index file. The entry
is given pointer information indicative of the decode
information of the specified content file.
The management information stored in the built-in memory
of the system control microcomputer 19 is updated in
correspondence with the recording of the content file. After
the index file has been updated or when the optical disk 2 is
unloaded, the management information recorded on the optical
disk 2 is updated on the basis of the updated management
information.
The operation of reproducing a content file with
reference to a list of the content files recorded on the optical
disk 2 will be described.
When the user gives an instruction to display a list of
content files, thumbnail picture data corresponding to the
content files is sequentially acquired from the data of the
index file stored in the built-in memory of the system control
microcomputer 19, and the thumbnail picture data in list form
is supplied from the system control microcomputer 19 to a
display means (not shown) via the file decoder 16 and the video
decoder 13. The display means displays the list of the
thumbnail pictures of the content files recorded on the optical
disk 2.
The system control microcomputer 19 reproduces the index
file from the optical disk 2 and stores it in the built-in memory,
as described above, and then determines whether the content
file can be reproduced by the optical disk unit 1 every decode
information stored in the decode-information storage area of
the index file . The determination is stored in a predetermined
storage area in association with pointer information
(indicative of decode information in the decode-information
storage area) . The content files to be displayed in list form
include all the content files recorded on the optical disk 2
or only content files that are determined to be reproducible.
When the user selects a thumbnail picture and gives an
instruction to reproduce it with thumbnail pictures displayed
in list form on the display means, a content file corresponding
to the thumbnail picture selected from the optical disk 2 is
reproduced under the control of the system control
microcomputer 19, when it is reproducible, on the basis of the
data of the index file stored in the built-in memory and
management information of the management system. In this case,
the content file reproduced from the optical disk 2 is acquired
via the optical pickup 33, the modem 23, the error-collection
encoder/decoder 21, and the memory controller 18. The
reproduced content file is divided into the elementary streams
of video data and audio data by the file decoder 16, and the
elementary streams are decoded by the video decoder 13 and the
audio decoder 14, respectively, and are output.
The index-file update process by the system control
microcomputer 19 will be further described.
When a content file is recorded on the optical disk 2,
as described above, the system control microcomputer 19 updates
the index file so as to add the content file.
The index file includes the text file FTX, the thumbnail
picture file FTH, and the property file FP, as described with
reference to Fig. 9. In this embodiment, particularly, an
index file including the property file FP, the thumbnail
picture file FTH, and the text file (or a meta-data file) FTX
is referred to as an AV-Index file.
The attribute information of each content file is divided
into a text file, a thumbnail picture file, and a property file.
Each file has continuous entries according to the attribute
information of the content file. The entries each include one
or a plurality of fixed-length slots . The entries each include
a management information area.
The entries (parity entries) of the property file FP are
each assigned a disk title and data indicative of the attribute
of the content file. The entries of the property file FP have
management information that specifies the corresponding
entries of the text file FTX and the thumbnail picture file
FTH. The entries of the property file FP each including a
plurality of slots have management information that specifies
a slot following the previous slot. The entries of the property
file FP each have information that specifies the corresponding
content file. Furthermore, the entries of the property file
FP each have information that defines the hierarchical
structure of the content file, existent folders, and virtual
folders.
Each file has continuous fixed-length slots each managed
by a slot number indicative of the order from the head of the
file. The slot numbers have index information indicative of
the order of the arrangement of the fixed-length slots of the
file. The index file has a predetermined number of entries
(management information areas) each including one or a
plurality of slots. The entries are each identified by the
number of the first fixed-length slot of the one or plurality
of connected slots.
The entries of the property file FP each have slots as
many as at least the slots assigned to the corresponding entries
of the other files. For example, when the thumbnail picture
file FTH and the text file FTX each have entries including two
slots for one content file, the corresponding entry of the
property file FP is assigned at least two slots.
The property file FP has a system information entry
following the header. Fig. 2 shows the structure of the
property file FP. The system information entry has a
decode-information storage area, in which all the decode
information of the content files recorded on the optical disk
2 is stored.
As shown in Fig. 2, the property file FP has continuous
entries corresponding to the content files following the system
information entry. The entry corresponding to each content
file is hereinafter referred to as "a file entry" as appropriate
in contrast with the system information entry.
The file entry has a profile entry index indicative of
decode information of a corresponding content file out of the
decode information recorded on the system information entry.
The profile entry index has pointer information.
The system information entry has a profile data list.
The profile data list includes AV profile entries on which
decode information is recorded by the number of the kinds of
decode information of the content files recorded on the optical
disk 2.
Fig. 2 shows an example in which video data and audio
data are decoded by processing the content file corresponding
to the first file entry on the basis of the decode information
recorded on the first AV profile entry #1 of the profile data
list. The example of Fig. 2 also shows that the video data
and the audio data are decoded by processing the content files
corresponding to the following two file entries on the basis
of the decode information recorded on the third AV profile entry
#3 of the profile data list.
Fig. 3 shows the structure of the profile data list of
the system information entry. In the profile data list, the
first 4 bytes are assigned the size (size) of the data block
of the profile data list, and the following 2 bytes are assigned
the type, data_type (= Profile Data List) , indicative of that
the data block is a profile data list.
In this profile data list, the following 2 bytes are
assigned the number of AV profile entries (entry_count) in the
profile data list, and the following 96 x N bytes are each
assigned a 96-byte AV profile entry (av_profile_entry) in
sequence by the number N of the entries.
Fig. 4 shows the structure of the AV profile entry. The
AV profile entry includes a video profile entry
(video_prof ile_entry) that is decode information of video data
and an audio prof ile entry (audio_prof ile_entry) that is decode
information of audio data.
Fig. 5 shows the structure of the video profile entry.
The video profile entry has a structure in which the first 4
bytes are assigned the size (size) of the data block of the
video profile entry, and the following 4 bytes are assigned
the type, data_type (= Profile Data for Video), indicative of
that the data block is a video profile entry.
In the video profile entry, the following 1 byte is
assigned the version (version) of the video profile entry; the
following 3 bytes are assigned a flag (flags) that specifies
the data type of the video profile entry; and the following
4 bytes are assigned a reserve (reserved).
31
In the video profile entry, the following 4 bytes are
assigned data-compression format information (codec_type) of
the video data, on which a format such as MPEG4 or AVC is recorded,
and the following 4 bytes are assigned specific set information
on the data-compression format (codec_specific_information),
on which the level of the format and so on are recorded.
In the video profile entry, the following 4 bytes are
assigned a video attribute flag (video_attribute_flags), on
which the presence of security, the system of scanning and so
on are recorded; and the following 4 bytes are assigned the
average bit rate (average_bitrate), the maximum bit rate
(max_bitrate), the average frame rate (average_frame_rate),
the maximum frame rate (max_frame_rate), the number of
horizontal and vertical samplings on one screen (visual_size) ,
and the aspect ratio (pixel_aspect_ratio), respectively.
Fig. 6 shows the structure of the audio profile entry.
The audio profile entry has a structure in which the first 4
bytes are assigned the size (size) of the data block of the
audio profile entry, and the following 4 bytes are assigned
the type, data_type (= Profile Data for Audio) , indicative of
that the data block is an audio profile entry.
In the audio profile entry, the following 1 byte is
assigned the version (version) of the audio profile entry; the
following 3 bytes are assigned a flag (flags) that specifies
the data type of the audio profile entry; and the following
4 bytes are assigned a reserve (reserved).
In the audio profile entry, the following 4 bytes are
assigned data-compression format information (codec_type) of
the audio data, and the following 4 bytes are assigned specific
set information on the data-compression format
(codec_specif ic_information) , on which the level of the format
and so on are recorded.
In the audio profile entry, the following 4 bytes are
assigned an audio attribute flag (Audio_attribute_flags), on
which the presence of security, the system of scanning and so
on are recorded; and the following 4 bytes are assigned the
average bit rate (average_bitrate), the maximum bit rate
(max_bitrate), the sampling rate (sampling_rate), and the
number of channels of the audio data (audio_channel_number),
respectively.
The flowchart of Fig. 7 shows the procedure of recording
content files by the system control microcomputer 19.
When the optical disk 2 is loaded, the system control
microcomputer 19 proceeds from step SP1 to step SP2 . In step
SP2, the system control microcomputer 19 acquires the index
file recorded on the optical disk 2, and stores it in the
built-in memory. In step SP3, the system control
microcomputer 19 records a content file on the optical disk
2 according to the user operation.
Upon completion of the recording of the content file,
at step SP4, the system control microcomputer 19 sequentially
searches the AV profile entries recorded on the system
information entry (see Fig. 2) of the index file on the basis
of the decode information of the content file to determine
whether the decode information of the specified content file
has already been recorded on the system information entry.
At the determination, the system control microcomputer
19 first detects an AV profile entry that is determined to have
been recorded in the same recording mode as that of the content
file recorded on the optical disk 2 as follows:
The system control microcomputer 19 detects a video
profile entry (video_profile_entry) in which the
data-compression format information (codec_type), the
specific set information on the format
(codec_specific_information) , the video attribute flag
(video_attribute_flags) , the number of horizontal and
vertical samplings on one screen (visual_size) , and the aspect
ratio (pixel_aspect_ratio) correspond to the recorded content
file.
Of the detected AV profile entries of the video profile
entry, the system control microcomputer 19 finds an audio
profile entry in which the audio-data-compression format
information (codec_type), the specific set information on the
format (codec_specific_information) , the audio attribute flag
(audio_attribute_flags), the sampling rate (sampling_rate),
and the number of channels (audio_channel_number) correspond
to the recorded content file.
The system control microcomputer 19 thus detects an AV
profile entry that is determined to have been recorded in the
same recording mode as that of the content file recorded on
the optical disk 2.
The system control microcomputer 19 then rounds up
predetermined digits of the bit rate and the frame rate of the
recorded content file to thereby determine an AV profile entry
whose bit rate and frame rate are the same as the rounded value
from the found AV profile entries.
When the AV profile entries recorded on the system
information entry include AV profile entries that are
determined to have been recorded in the same recording mode
as the recorded content file, and when the AV profile entries
have the same bit rate and frame rate as the rounded bit rate
and frame rate of the recorded content file, the system control
microcomputer 19 determines that the decode information of the
recorded content file (AV profile entry) has already been
recorded on the system information entry.
Since the system control microcomputer 19 makes a
determination including the round-up of the bit rate and the
frame rate, a plurality of pieces of decode information having
strictly different bit rates and frame rates can be expressed
collectively. This reduces the number of the AV profile
entries in the system information entry, thus reducing the size
of the index file.
The round-up is executed by a device that reproduces a
content file according to the bit rate and the frame rate
recorded on the AV profile entry and a significant digit with
which the recorded content file can be determined to be
reproducible. For example, when the frame rate of the recorded
content file is a frame frequency of 29.94 Hz, the system
control microcomputer 19 detects an AV profile entry with a
frame frequency of 30 Hz.
The system control microcomputer 19 may not make a
determination including the round-up of the bit-rate and the
frame rate, but may make a determination whether the decode
information of the recorded content file has already been
recorded on the system information entry, depending on whether
there is a content file with completely the same bit rate and
frame rate.
When it is determined at step SP4 that the decode
information of the recorded content file has already been
recorded on the system information entry, the system control
microcomputer 19 proceeds from step SP4 to step SP5 . At step
SP5, the system control microcomputer 19 adds the entry of the
recorded content file to the property file FP.
At step SP6, the system control microcomputer 19 sets
a property entry index (pointer information) to the added file
entry so as to indicate the AV profile entry of the recorded
decode information which is detected by the process of step
SP4. At step SP7, the system control microcomputer 19
determines whether the user has given an instruction to
terminate the operation. When the instruction to terminate
the operation is not given, the process returns from step SP7
to step SP3, wherein the following content file is recorded
in response to the user operation. On the other hand, when
an instruction to terminate the operation is given, the process
ends at step S9.
When it is determined at step SP4 that the decode
information of the recorded content file has not yet been
recorded on the system information entry, the system control
microcomputer 19 proceeds from step SP4 to step SP8 . At step
SP8, the system control microcomputer 19 creates an AV profile
entry on the basis of the decode information of the recorded
content file, and adds the AV profile entry to the profile data
list.
At the following step SP5, the system control
microcomputer 19 adds the entry of the content file to the
property file FP. At the next step SP6, the system control
microcomputer 19 sets a property entry index (pointer
information) to the file entry added at step SP5 so as to
indicate the AV profile entry added at step SP8.
The procedure of the flowchart in Fig. 7 is such that
after a specified content file has been recorded on the optical
disk 2, it is determined whether the decode information of the
recorded content file has been recorded on the system
information entry, wherein when the information has not been
recorded, it is added. Alternatively, it may be determined
whether the decode information of the content file has been
recorded on the system information entry before the content
file is recorded on the optical disk 2, wherein when it has
not been recorded, it may be added and then the content file
may be recorded on the optical disk 2.
In registering an AV profile entry to the system
information entry, in place of the decode information of the
recorded content file, decode information on the corresponding
recording mode of another recording apparatus with different
bit rate may be recorded. In this case, the recording apparatus
is sometimes for general purpose use.
For example, an AV profile entry may be registered in
correspondence with the profile level of a memory stick
moving-image format. That is, when the recording level is
specified by the format or rule (for example, when the recording
level is specified at 128 kbps for level 1 and 256 kbps for
level 2), even if a content file is recorded at 150 kbps by
an actual device, not the 150 kbps but the upper limit 256 kbps
of the bit rate for the moving format is registered to the AV
profile entry.,
The flowchart of Fig. 8 shows the procedure of the system
control microcomputer 19 in a content-file reproducing mode.
For example, when the optical disk 2 is loaded, the system
control microcomputer 19 proceeds from step SP11 to step SP12.
At step SP12, the system control microcomputer 19 acquires the
index file recorded on the optical disk 2, and stores it in
the built-in memory.
At step SP13, the system control microcomputer 19
determines whether the AV property entries recorded on the
profile data list of the acquired index file can be processed
according to the decode information recorded on the AV property
entries.
That is, the system control microcomputer 19 determines
whether the content file based on the AV property entries can
be reproduced, and stores the determination in a predetermined
storage area such as a built-in memory in association with the
profile entry index serving as pointer information. In the
embodiment, the system control microcomputer 19 stores a
profile entry index indicative of an AV property entry that
is determined to be reproducible in the built-in memory.
At the next step SP14, the system control microcomputer
19 accepts the selection of a content file to be reproduced
according to user operation, and detects a corresponding file
entry from the index file. For example, the system control
microcomputer 19 accepts selection by the user by displaying
the list of thumbnail pictures of the thumbnail picture file
or the list of titles of the text file stored in the index file.
At the next step SP15, the system control microcomputer
19 determines whether the file entry detected from the index
file has the profile entry index stored in the built-in memory
at step SP13. When the system control microcomputer 19
determines that the file entry detected from the index file
has not the profile entry index stored in the built-in memory,
the procedure proceeds from step SP15 to step SP16.
At step SP16, the system control microcomputer 19
notifies the user that the content file cannot be reproduced,
and then returns to step SP14. The notification to the user
may adopt various ways including a message that the content
file cannot be reproduced.
In contrast, when it is determined at step SP15 that the
file entry detected from the index file has the profile entry
index stored in the built-in memory, the system control
microcomputer 19 proceeds from step SP15 to step SP17. At step
SP17, the system control microcomputer 19 determines that the
content file selected by the user can be reproduced, and at
step SP18, controls the overall operation to reproduce the
content file. After the content file has been reproduced, the
system control microcomputer 19 returns to step SP14.
The procedure shown in Fig. 8 uses the result of
determination at step SP13 for the determination at step SP15,
that is, the result of determination whether the process based
on the decode information recorded on the AV property entries
on the profile data list of the index file can be executed,
allowing high-speed determination of whether a content file
can be reproduced. Alternatively, the determination at step
SP13 may be omitted; it may be determined at step SP15 whether
the process based on the decode information of the AV property
entry indicated by the profile entry index set at the file entry
corresponding to the content file can be executed, and then
a determination whether the content file can be reproduced may
be made.
With the optical disk unit 1 shown in Fig. 1, all the
decode information of the content files recorded on the optical
disk 2 is stored in the system information entry of the index
file; and the entries (file entries) of the index file
corresponding to the content files have profile entry index
(pointer information) indicative of the corresponding AV
profile entries (decode information) of the system information
entry (decode-information storage area). Accordingly, the
use of the optical disk unit 1 prevents duplicate recording
of decode information on the index file, and allows decode
information to be recorded without being coded. Therefore,
detailed decode information of the content files can be
recorded without a significant increase in the size of the index
file.
With the optical disk unit 1 shown in Fig. 1, if an AV
profile entry (decode information) corresponding to a content
file to be registered is not recorded on the system information
entry (decode-information storage area) at the time of updating
the index file, an AV profile entry (decode information)
corresponding to the content file is added. Therefore, the
optical disk unit 1 is suitable also for recording a content
file that does not correspond to the AV profile entries (decode
information) in the system information entry
(decode-information storage area) on the optical disk 2.
With the optical disk unit 1 shown in Fig. 1, at the time
of reproducing a content file from the optical disk 2, it is
determined whether the content file can be reproduced on the
basis of the AV profile entry (decode information) of a system
information entry (decode-information storage area) indicated
by the profile entry index (pointer information) of an entry
(file entry) of the index file corresponding to the content
file. Accordingly, the optical disk unit 1 allows
determination of reproducibility based on the AV profile entry
(decode information) itself corresponding to the content file,
leading to accurate determination whether the content file can
be reproduced.
According to the procedure shown in Fig. 8, the
determination of reproducibility is made for a content file
selected by a user, wherein when it is determined to be
reproduced, the content file is reproduced. It is also
possible that only reproducible content files are displayed
in list form in advance, from which the user selects a content
file, and that unreproducible content files cannot be
recognized by the user.
In the foregoing embodiment, the index file includes a
text file FTX, a thumbnail picture file FTH, and a property
file FP, and the attribute information of the content files
are grouped and disposed in the respective files. However,
the invention is not limited to that; it can also be applied
to an index file composed of one file.
Although the foregoing embodiment is an application to
the optical disk unit 1, the invention is not limited to that;
it can be broadly applied to receding of content files on
various recording media such as a hard disk or a memory card,
or read-only recording media.
In the foregoing embodiment, the encoder and the decoder
are integrated to one. However, the invention is not limited
to that; it may be broadly applied to a structure in which the
encoder and the decoder are achieved by a software process,
and a structure in which compressed video data and audio data
are input and recorded from an external unit, and the encoder
and the decoder are disposed in the external unit.
Industrial Applicability
The invention allows decode information of content files
to be recorded in detail without a significant increase in the
size of the index file, thereby allowing accurate determination
of the reproducibility of the content files. For example, the
invention can be applied to an optical disk unit.

CLAIMS
1. A recording apparatus for recording a content file
including at least encoded video data or encoded audio data
and an index file for managing the content file and including
a set of attribute information of the content file on a
recording medium, the recording apparatus comprising:
a content-file recording section for recording the
content file on the recording medium; and
an index-file updating section for updating the index
file so as to register a desired content file when the content
file is recorded on the recording medium by the content-file
recording section; wherein
the index file includes a predetermined number of entries
corresponding to the content file recorded on the recording
medium and assigned the attribute information of the
corresponding content file and a decode-information storage
area for storing decode information of the content file;
the predetermined number of entries have pointer
information indicative of decode information of the
corresponding content file from among the decode information
stored in the decode-information storage area; and
the index-file updating section adds an entry to the
index file when updating the index file so as to register the
content file, the entry being corresponding to the content file
and having pointer information indicative of the decode
information of the content file stored in the
decode-information storage area.
2. The recording apparatus according to Claim 1, wherein
when updating the index file so as to register the desired
content file, the index-file updating section adds the decode
information of the content file to the decode-information
storage area when the decode information of the content file
is not stored in the decode-information storage area.
3 . The recording apparatus according to Claim 2, wherein
when decode information is stored in the
decode-information storage area, the decode information being
different in bit rate or frame rate from the decode information
of the desired content file and having a bit rate or a frame
rate that is obtained by rounding up a predetermined digit of
the bit rate or the frame rate of the decode information of
the content file, the index-file updating section determines
that decode information of the content file is stored in the
decode-information storage area.
4 . A method for recording a content file including at
least encoded video data or encoded audio data and an index
file for managing the content file and including a set of
attribute information of the content file on a recording medium,
the method comprising:
a content-file recording step of recording the content
file on the recording medium; and
an index-file updating step of updating the index file
so as to register a desired content file when the content file
is recorded on the recording medium at the content-file
recording step; wherein
the index file includes a predetermined number of entries
corresponding to the content file recorded on the recording
medium and assigned the attribute information of the
corresponding content file and a decode-information storage
area for storing decode information of the content file;
the predetermined number of entries have pointer
information indicative of decode information of the
corresponding content file from among the decode information
stored in the decode-information storage area,- and
at the index-file updating step, an entry is added to
the index file when updating the index file so as to register
the content file, the entry being corresponding to the content
file and having pointer information indicative of the decode
information of the content file stored in the
decode-information storage area.
5. A reproducing apparatus for reproducing a desired
content file from a recording medium on which a content file
including at least encoded video data or encoded audio data
and an index file for managing the content file and including
a set of attribute information of the content file are recorded,
wherein
the index file includes a predetermined number of entries
corresponding to the content file recorded on the recording
medium and assigned the attribute information of the
corresponding content file and a decode-information storage
area for storing all the decode information of the content f ile ;
and
the predetermined number of entries have pointer
information indicative of decode information of the
corresponding content file from among the decode information
stored in the decode-information storage area; and wherein the
reproducing apparatus comprises:
a content-file reproducing section for reproducing a
desired content file from the recording medium to acquire video
data or audio data contained in the content file; and
an index-file reproducing section for reproducing the
index file from the recording medium;
wherein the content-file reproducing section determines
whether the content file can be reproduced with reference to
the decode information on the basis of the pointer information.
O. The reproducing apparatus according to Claim ^
wherein the content-file reproducing section determines
whether the content file can be reproduced for each decode
information stored in the decode-information storage area of
the index file reproduced by the index-file reproducing section,
and stores the result of determination in a predetermined
storage area in association with the corresponding pointer
information; and when reproducing a desired content file from
the recording medium, the content-file reproducing section
determines whether the content file can be reproduced on the
basis of the determination result stored in the predetermined
storage area in association with the pointer information of
the entry of the index file corresponding to the content file.
7. A method for reproducing a desired content file from
a recording medium on which a content file including at least
encoded video data or encoded audio data and an index file for
managing the content file and including a set of attribute
information of the content file are recorded, wherein
the index file includes a predetermined number of entries
corresponding to the content file recorded on the recording
medium and assigned the attribute information of the
corresponding content file and a decode-information storage
area for storing all decode information of the content file/
and
the predetermined number of entries have pointer
information indicative of decode information of the
corresponding content file from among the decode information
stored in the decode-information storage area, and wherein the
method comprises:
a content-file reproducing step of reproducing a desired
content file from the recording medium to acquire video data
or audio data contained in the content file; and
an index-file reproducing step of reproducing the index
file from the recording medium;
wherein at the content-file reproducing step, it is
determined whether the content file can be reproduced with
reference to the decode information on the basis of the pointer
information.
8 . A recording medium on which a content file including
at least encoded video data or encoded audio data and an index
file for managing the content file and including a set of
attribute information of the content file are recorded, wherein
the index file includes a predetermined number of entries
corresponding to the content file and assigned the attribute
information of the corresponding content file and a
decode-information storage area for storing all the decode
information of the content file; and
the predetermined number of entries have pointer
information indicative of decode information of the
corresponding content file from among the decode information
stored in the decode-information storage area.