U.S. patent application number 12/591709 was filed with the patent office on 2010-03-25 for file reproduction apparatus, file reproduction method, file reproduction method program and recording medium for recording file reproduction method program.
This patent application is currently assigned to Sony Corporation. Invention is credited to Hiroshi Jinno, Shigeru Kashiwagi, Masaharu Murakami, Haruo Yoshida.
Application Number | 20100074601 12/591709 |
Document ID | / |
Family ID | 34431092 |
Filed Date | 2010-03-25 |
United States Patent
Application |
20100074601 |
Kind Code |
A1 |
Murakami; Masaharu ; et
al. |
March 25, 2010 |
File reproduction apparatus, file reproduction method, file
reproduction method program and recording medium for recording file
reproduction method program
Abstract
The present invention is applied to reproduction of typically a
fragment movie file having a QT format. In accordance with the
present invention, management information associated with each
block following a first block of the fragment movie file is
modified to information compatible with management information
associated with the first block and real data of the file is
reproduced on the basis of the modified management information.
Inventors: |
Murakami; Masaharu; (Tokyo,
JP) ; Kashiwagi; Shigeru; (Tokyo, JP) ;
Yoshida; Haruo; (Kanagawa, JP) ; Jinno; Hiroshi;
(Kanagawa, JP) |
Correspondence
Address: |
RADER FISHMAN & GRAUER PLLC
LION BUILDING, 1233 20TH STREET N.W., SUITE 501
WASHINGTON
DC
20036
US
|
Assignee: |
Sony Corporation
Tokyo
JP
|
Family ID: |
34431092 |
Appl. No.: |
12/591709 |
Filed: |
November 30, 2009 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10574930 |
Apr 7, 2006 |
7653286 |
|
|
PCT/JP2004/015198 |
Oct 7, 2004 |
|
|
|
12591709 |
|
|
|
|
Current U.S.
Class: |
386/241 ;
386/E5.001 |
Current CPC
Class: |
G11B 27/11 20130101;
G11B 27/322 20130101; G11B 2020/10944 20130101; G11B 27/105
20130101; G11B 27/3027 20130101 |
Class at
Publication: |
386/124 ;
386/E05.001 |
International
Class: |
H04N 7/26 20060101
H04N007/26 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 10, 2003 |
JP |
2003-351844 |
Claims
1. A file reproduction apparatus for reproducing a file recorded on
a recording medium, wherein: said file is as a file containing real
data and management information used for reproducing said real
data; said management information is provided for each of blocks
composed of a first block and a sequence of subsequent blocks
following said first bock as blocks of said real data; said
management information associated with each of said subsequent
blocks included in said real data as blocks other than said first
block of said real data is provided as information including
standard settings and at least some settings taking said standard
settings as a reference; said management information associated
with said first block of said real data is provided as settings
corresponding to said standard settings; said management
information associated with each of said subsequent blocks is
modified to settings compatible with said management information
associated with said first block; and said real data is reproduced
on the basis of said modified management information.
2. The file reproduction apparatus according to claim 1, wherein:
said real data is video data and; said management information is
provided for each sample corresponding to a frame of said real
data.
3. The file reproduction apparatus according to claim 2, wherein:
one piece of said management information provided for a sample is
an identification showing that said sample is a random-accessible
sample; and on the basis of said identification included in said
modified management information, said reproduction apparatus
selectively reproduces said real data in order to reproduce said
real data at a variable speed.
4. The file reproduction apparatus according to claim 2, wherein:
one piece of said management information is position information
corresponding to a reproduction time of said real data; and on the
basis of said position information included in said modified
management information, said reproduction apparatus starts a
process to reproduce said real data in order to commence
reproduction of said real data at a reproduction time indicated by
said position information.
5. The file reproduction apparatus according to claim 1, wherein:
said modified management information associated with a plurality of
said blocks is stored in a memory as information necessary for a
process to reproduce said real data; and said modified management
information associated with a block already completing said process
to reproduce said real data is deleted from said memory and
management information associated with a next block following a
plurality of said blocks is modified to settings compatible with
said management information associated with said first block, being
stored in said memory.
6. The file reproduction apparatus according to claim 5, wherein:
said modified management information associated with a plurality of
said blocks includes boundary information stored in said memory as
information showing boundaries between said blocks; and said
modified management information associated with a block already
completing said process to reproduce said real data is deleted from
said memory by taking said boundary information as a reference.
7. The file reproduction apparatus according to claim 1, wherein
said modified management information is recorded onto said
recording medium and used for creation of another file used for
referencing said real data stored in said file as another file
having an external reference format.
8. A file reproduction method for reproducing a file recorded on a
recording medium, wherein: said file is as a file containing real
data and management information used for reproducing said real
data; said management information is provided for each of blocks
composed of a first block and a sequence of subsequent blocks
following said first bock as blocks of said real data; said
management information associated with each of said subsequent
blocks included in said real data as blocks other than said first
block of said real data is provided as information including
standard settings and at least some settings taking said standard
settings as a reference; said management information associated
with said first block of said real data is provided as settings
corresponding to said standard settings; said management
information associated with each of said subsequent blocks is
modified to settings compatible with said management information
associated with said first block; and said real data is reproduced
on the basis of said modified management information.
9. A program to be executed by a computer as a program implementing
a file reproduction method for reproducing a file recorded on a
recording medium by execution of a predetermined processing
procedure, wherein: said file is created to as a file containing
real data and management information used for reproducing said real
data; said management information is provided for each of blocks
composed of a first block and a sequence of subsequent blocks
following said first bock as blocks of said real data; said
management information associated with each of said subsequent
blocks included in said real data as blocks other than said first
block of said real data is provided as information including
standard settings and at least some settings taking said standard
settings as a reference; and said management information associated
with said first block of said real data is provided as settings
corresponding to said standard settings, said processing procedure
comprises the steps of: modifying said management information
associated with each of said subsequent blocks to settings
compatible with said management information associated with said
first block; and reproducing said real data on the basis of said
modified management information.
10. A recording medium used for storing a program to be executed by
a computer as a program implementing a file reproduction method for
reproducing a file recorded on another recording medium by
execution of a predetermined processing procedure, wherein: said
file is created to as a file containing real data and management
information used for reproducing said real data; said management
information is provided for each of blocks composed of a first
block and a sequence of subsequent blocks following said first bock
as blocks of said real data; said management information associated
with each of said subsequent blocks included in said real data as
blocks other than said first block of said real data is provided as
information including standard settings and at least some settings
taking said standard settings as a reference; and said management
information associated with said first block of said real data is
provided as settings corresponding to said standard settings; and
said processing procedure comprises the steps of: modifying said
management information associated with each of said subsequent
blocks to settings compatible with said management information
associated with said first block, reproducing said real data on the
basis of said modified management information.
Description
[0001] This is a Continuation Application of U.S. patent
application Ser. No. 10/574,930, filed Apr. 7, 2006, which is based
on a National Stage Application of PCT/JP04/015198, filed Oct. 7,
2004, which in turn claims priority from Japanese Application
No.:2003-351844, filed on Oct. 10, 2003, the entire contents of
which are incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to file reproduction
apparatus, a file reproduction method, a program implementing the
file reproduction method and a recording medium for recording the
program implementing the file reproduction method. For example, the
present invention can be applied to reproduction of a fragment
movie file conforming to an ISO base media file format (MPEG-4 part
12) taking a QT format as a base. The present invention is provided
as means for reproducing real data of a fragment movie file by
modifying management information set in each block following a head
block of the fragment movie file to make the management information
set in each following block compatible with the management
information set in the head block. By making the management
information set in each subsequent block compatible with the
management information set in the head block, it is possible to
simplify processing carried out to reproduce the fragment movie
file or the like.
BACKGROUND ART
[0003] In the past, a quick-time file format (referred to hereafter
simply as a QT format) was used in a broader range of applications
as a file format for multimedia.
[0004] In accordance with the QT format, real data including moving
pictures, still pictures and sound is divided into blocks. In
addition, management information used for managing the real data is
also divided into blocks separated from the blocks of the real
data. In the following description, blocks of the management
information and the real data are each referred to as an atom.
Moreover, atoms of the real data and the management information are
further divided into sub-blocks to form a hierarchical structure.
In the case of the real data, a smallest management unit is
referred to as a sample, and one sample or a plurality of samples
forms a chunk, which is used as an upper-level management unit.
Then, in the case of a file created from blocks as a file
conforming to the QT format, considering convenience of processing,
normally, one frame serving as a display unit or a GOP (Group of
Pictures) is set in one sample as disclosed in a document such as
Japanese Patent Laid-Open No. 2001-94933.
[0005] In general, a file having a QT format includes atoms of two
different types, that is to say, a movie data atom of collected
real data and a movie atom of collected management information.
[0006] By the way, in addition to the same recording method as the
method for the QT format, a recording method for the so-called
fragment movie format is applied as a recording method for the ISO
base media file format (MPEG-4 part 12) taking the QT format as a
base to apparatus with few resources and apparatus for which it is
feared that the power supply thereof is down in the course of a
recording process.
[0007] For the reason described above, the real data of an ISO base
media file containing a fragment movie is segmented into a
plurality of blocks each having a predetermined size in the
progressing direction along the time axis as shown in FIG. 1. In
the figure, the blocks of the real data are each shown as a block
corresponding to one of a plurality of movie data atoms mdat0,
mdat1, mdat2 and so on. In the following description, the ISO base
media file is also referred to as a fragment movie file. The
fragment movie file also includes a movie atom moov, associated
with the movie data atom mdat0 serving as the first atom in the
series of aforementioned movie data atoms mdat0, mdat1, mdat2 and
so on. The movie atom moov has the same atom structure as the
ordinary QT movie file. The movie atom moov is formed as an atom
referring to the movie data atom mdat0 as shown by an uppermost
arrow in the figure so as to allow video data allocated to the
movie data atom mdat0 as real data to be reproduced. It is to be
noted that the first movie data atom mdat0 is also known as an
initial moov. Thus, in the following description, the first movie
data atom mdat0 is also referred to as an initial moov atom.
[0008] In addition, the fragment movie file also includes an atom
moof containing management information associated with each of the
movie data atoms mdat1, mdat2 and so on. As shown in the figure,
the atoms moof each containing management information are denoted
by reference notations moof1, moof2 and so on. In the following
description, the atoms moof1, moof2 and so on are each referred to
as a moof atom. The moof atoms moof1, moof2 and so on are formed as
atoms referring to their respective movie data atoms mdat1, mdat2
and so on respectively as shown by subsequent arrows in the figure
so as to allow pieces of video data allocated to the movie data
atoms mdat1, mdat2 and so on as pieces of real data to be
reproduced.
[0009] Thus, while the movie data atoms mdat0, mdat1, mdat2 and so
on are being stored sequentially in a created fragment movie file
in a recording process, the initial moov atom associated with mdat0
as well as the moof atoms moof1, moof2 and so on associated with
the movie data atoms mdat1, mdat2 and so on respectively are also
stored on the created file sequentially as well. Thus, even an
apparatus having few resources is capable of recording a fragment
movie file with a large size onto a recording medium. In addition,
even if the power supply thereof is down in the course of a
recording process, video data up to a portion corresponding to the
down event can be recorded in a reproducible state onto the
recording medium.
[0010] In addition, in a fragment movie file, the initial moov atom
has a structure of management information associated with the video
data of the movie data atom mdat0. The management information set
in the initial moov is set for chunks of the movie data atom mdat0
and samples of each of the chunks. The chunks and samples are each
used as a management unit of real data much like the movie atom of
the ordinary QT movie file. On the other hand, the moof atoms
moof1, moof2 and so on are each provided with a structure different
from the initial moov atom with an objective to reduce the amount
of management information accommodated in the moof atom. That is to
say, with every default setting in each of the moof atoms moof1,
moof2 and so on as a reference, the moof atoms moof1, moof2 and so
on can each have a structure of condensed set management
information related to the movie data atoms mdat1, mdat2 and so on
respectively for each sample.
[0011] Thus, in processing to reproduce a fragment movie file, it
is necessary to switch the reproduction processing from the initial
moov atom to one of the moof atoms moof1, moof2 and so on. As a
result, the fragment movie file raises a problem of complicated
processing carried out at a reproduction time.
DISCLOSURE OF INVENTION
[0012] It is thus an object of the present invention addressing the
problems described above to provide a file reproduction apparatus
and a file reproduction method, which are capable of simplifying
processing carried out to reproduce a fragment movie file, as well
as provide a program implementing the file reproduction method and
a recording medium used for recording the program implementing the
file reproduction method.
[0013] The file reproduction apparatus to which the present
invention is applied for solving the problems is an apparatus for
reproducing a file from a recording medium by modification of
management information associated with each block following a head
block of the file to information settings compatible with
management information associated with the head block and
reproduction of real data of the file on the basis of the modified
management information.
[0014] In accordance with the above configuration of the present
invention, the present invention is applied to the file
reproduction apparatus for reproducing a file recorded on a
recording medium by modification of management information
associated with each block following a head block of the file to
information settings compatible with management information
compatible with the head block and reproduction of real data of the
file on the basis of the modified management information so that,
in a process to reproduce the real data of the file, the real data
can be reproduced by carrying out a reproduction operation based on
the management information associated with the head block and a
reproduction operation based on the management information
associated with each of the blocks following the head block in the
same processing. As a result, the processing to reproduce a
fragment movie file or the like can be made simple.
[0015] In addition, the file reproduction method to which the
present invention is applied is a method for reproducing a file
from a recording medium by modification of management information
associated with each block following a head block of the file to
information settings compatible with management information
associated with the head block and reproduction of real data of the
file on the basis of the modified management information.
[0016] As a result, in accordance with the above configuration of
the present invention, it is possible to provide a file
reproduction method capable of simplifying the processing to
reproduce a fragment movie file or the like.
[0017] In addition, the program to which the present invention is
applied is a program implementing a file reproduction method for
reproducing a file from a recording medium by execution of a
predetermined processing procedure including the steps of modifying
management information associated with each block following a head
block of the file to information settings compatible with
management information associated with the head block and
reproducing real data of the file on the basis of the modified
management information.
[0018] As a result, in accordance with the above configuration of
the present invention, it is possible to provide a program
implementing a file reproduction method capable of simplifying the
processing to reproduce a fragment movie file or the like.
[0019] In addition, the recording medium to which the present
invention is applied is a recording medium used for recording a
program implementing a file reproduction method for reproducing a
file from a recording medium by execution of a predetermined
processing procedure including the steps of modifying management
information associated with each block following a head block of
the file to information settings compatible with management
information associated with the head block and reproducing real
data of the file on the basis of the modified management
information.
[0020] As a result, in accordance with the above configuration of
the present invention, it is possible to provide a recording medium
used for recording a program implementing a file reproduction
method capable of simplifying the processing to reproduce a
fragment movie file or the like.
[0021] In accordance with the present invention, it is possible to
simplify processing carried out to reproduce a fragment movie file
or the like.
BRIEF DESCRIPTION OF DRAWINGS
[0022] FIG. 1 is an explanatory diagram showing a fragment movie
file in a simple manner;
[0023] FIG. 2 is a block diagram showing a video-disc apparatus
according to a first embodiment of the present invention;
[0024] FIG. 3 is a table referred to in explanation of sample
information of an initial moov atom in a fragment movie file;
[0025] FIG. 4 is a table showing typical concrete numerical
settings of the sample information shown in FIG. 3;
[0026] FIG. 5 is a table referred to in explanation of sample
information of a moof atom in a fragment movie file;
[0027] FIG. 6 is a table showing typical concrete numerical
settings of the sample information shown in FIG. 5;
[0028] FIG. 7 is a table referred to in explanation of concrete
processing of the sample information shown in FIG. 5;
[0029] FIG. 8 is a table referred to in explaining processing of
management information according to a second embodiment of the
present invention;
[0030] FIG. 9 is a table referred to in explanation of content
changes caused by switching of processing from a block to another
as content changes from the table shown in FIG. 7;
[0031] FIGS. 10A and 10B are diagrams referred to in explanation of
processing to update contents of a memory at a reproduction time in
the progressing direction along the time axis;
[0032] FIGS. 11A and 11B are diagrams referred to in explanation of
processing to update contents of a memory in the event of a skip;
and
[0033] FIG. 12 shows a flowchart representing a processing
procedure of a system control microcomputer 19 employed in a
video-disc apparatus according to the second embodiment of the
present invention.
BEST MODE FOR CARRYING OUT THE INVENTION
[0034] Embodiments of the present invention are explained in detail
by referring to diagrams as follows.
(1) Configuration of the Embodiments
(1-1) Overall Configuration of a Video-Disc Apparatus
[0035] FIG. 2 is a block diagram showing a video-disc apparatus
according to an embodiment of the present invention. In this
video-disc apparatus 1, image pickup means not shown in the figure
takes a video signal of an image pickup object and audio
acquisition means also not shown in the figure takes an audio
signal of the object. Then, an image pickup result represented by
the video and audio signals is recorded onto an optical disk 2. In
addition, an image pickup result recorded on the optical disk 2 is
reproduced and output to display means for displaying the result on
a liquid-crystal display panel, output to a speaker serving as
audio output means and output to an external apparatus. The image
pickup result shown to the user in this way can be edited by the
user in an editing process.
[0036] In the video-disc apparatus 1, an image pickup result
represented by video and audio signals is compressed in a data
compression process conforming to an MPEG format before being
recorded onto the optical disk 2 in an MPEG format. As the file
format, this embodiment adopts the format of a fragment movie
conforming to the ISO base media file format taking the QT format
as a base.
[0037] Thus, in the video-disc apparatus 1, a video coder 11
carries out an analog/digital conversion process on the video
signal of the result of image pickup in order to generate video
data. Then, the video coder 11 carries out an encoding process
conforming to the MPEG format on the video data in order to
generate an elementary stream of video data.
[0038] In the mean time, an audio coder 12 carries out an
analog/digital conversion process on the audio signal of the result
of image pickup in order to generate audio data. Then, the audio
coder 12 carries out an encoding process conforming to the MPEG
format on the audio data in order to generate an elementary stream
of audio data.
[0039] At a recording time, a file generator 15 synchronizes and
multiplexes the elementary streams generated by the video coder 11
and audio coder 12 in order to generate data of a fragment movie
file under control executed by a system control microcomputer 19.
To put it concretely, while multiplexing the sequentially received
elementary streams in order to generate data of movie data atoms in
predetermined block units, the file generator 15 additionally
creates data required for generating the initial moov atom and moof
atoms for the movie data atoms and holds the additionally created
data in an embedded memory 15A. As the process to generate blocks
of aforementioned movie data atoms to be recorded is completed, the
file generator 15 creates a data array consisting of the initial
moov and the moof atoms from the data held in the embedded memory
15A and outputs the array.
[0040] In accordance with control executed by a system control
microcomputer 19, a memory controller 18 switches the operation
thereof. At a recording time, the memory controller 18 sequentially
records a fragment movie file output by the file generator 15 in a
memory 17 and temporarily holds the file in the memory 17 before
outputting the file temporarily held in the memory 17 to an error
correction coder/decoder 21. The fragment movie file includes an
array of movie data atoms or the like. At a reproduction time, on
the other hand, the memory controller 18 temporarily holds data
output by the error correction coder/decoder 21 before outputting
the data to a file decoder 16 and the system control microcomputer
19.
[0041] In accordance with control executed by the system control
microcomputer 19, the error correction coder/decoder 21 also
switches the operation thereof. At a recording time, the error
correction coder/decoder 21 temporarily records data output by the
memory controller 18 in a memory 20 and adds error correction codes
to the stored data. Then, the error correction coder/decoder 21
reads out the data held in the memory 20 in this way in a
predetermined order in order to interleave the data before
outputting the interleaved data to a data modulator/demodulator 23.
At a reproduction time, on the other hand, the error correction
coder/decoder 21 temporarily records data output by the data
modulator/demodulator 23 into the memory 20 in a predetermined
order opposite to the order predetermined for the recording
operation before outputting the data to the memory controller 18.
That is to say, the error correction coder/decoder 21
de-interleaves the data output by the data modulator/demodulator 23
and outputs the de-interleaved data to the memory controller 18. At
that time, the error correction coder/decoder 21 also carries out
an error correction process on the data received from the data
modulator/demodulator 23 by using the error correction codes, which
were added to the data at a recording time.
[0042] In accordance with control executed by the system control
microcomputer 19, the data modulator/demodulator 23 also switches
the operation thereof. At a recording time, the data
modulator/demodulator 23 converts data output by the error
correction coder/decoder 21 into a serial data array before
modulating the array and outputting the modulated array to a
magnetic-field modulation driver 24 or an optical pickup 33. At a
reproduction time, on the other hand, the data
modulator/demodulator 23 reproduces a clock signal from a
reproduced signal output by the optical pickup 33. Then, by using
the clock signal as a reference, the data modulator/demodulator 23
carries out a binary recognition process and a demodulation process
on the reproduced signal in order to generate reproduced data of
the serial data array, which was generated at a recording time.
Subsequently, the data modulator/demodulator 23 outputs the
reproduced data to the error correction coder/decoder 21.
[0043] In the case of a magneto-optical disk used as the optical
disk 2, at a recording time, the magnetic-field modulation driver
24 drives a magnetic head 32 in accordance with a signal output by
the data modulator/demodulator 23 under control executed by the
system control microcomputer 19. The magnetic head 32 is held at a
position sandwiching the optical disk 2 in conjunction with the
position of the optical pickup 33, facing the optical pickup 33
through the optical disk 2. The magnetic head 32 applies a magnetic
field modulated by data output by the data modulator/demodulator 23
to a position radiated by a laser beam generated by the optical
pickup 33. Thus, in the case of a magneto-optical disk used in the
video-disc apparatus 1 as the optical disk 2, a thermo-magnetic
recording technique is adopted to record a result of image pickup
onto the optical disk 2 as a fragment movie file.
[0044] In the case of this embodiment, the optical disk 2 is a
recording medium having a shape resembling a disc. In this
embodiment, the optical disk 2 is a programmable optical disc such
as an MO (Magneto-Optical) disc or a disc of a phase-change type. A
spindle motor 31 is a motor for driving the optical disk 2 into
rotation in accordance with control executed by a servo circuit 30
under a condition determined by the type of the optical disk 2.
Examples of the condition are a CLV (Constant Linear Velocity)
condition, a CAV (Constant Angular Velocity) condition and a ZCLV
(Zone Constant Linear Velocity) condition.
[0045] On the basis of a variety of signals output from the optical
pickup 33, the servo circuit 30 controls the operation of the
spindle motor 31 in order to execute a spindle control process. The
servo circuit 30 also executes tracking control and focus control
of the optical pickup 33. In addition, the servo circuit 30 also
moves the optical pickup 33 and the magnetic head 32 in a seek
operation in order to search for a focus or carry out another
process.
[0046] A drive control microcomputer 22 is a component for
controlling the servo circuit 30 to carry out operations such as
the seek operation mentioned above in accordance with a command
given by the system control microcomputer 19.
[0047] The optical pickup 33 is a component for radiating a laser
beam to the optical disk 2 and having a predetermined light
reception device for receiving the laser beam reflected by the
optical disk 2. The optical pickup 33 then processes a result of
the light reception in order to generate a variety of output
control signals and output a reproduced signal with a signal level
thereof varying in accordance with a pit array and a mark array,
which have been created on the optical disk 2. In addition, in
accordance with control executed by the system control
microcomputer 19, the optical pickup 33 switches its operation. In
the case of a magneto-optical disk used as the optical disk 2, at a
recording time, the optical pickup 33 intermittently builds up the
optical quantity of the laser beam radiated to the optical disk 2.
Thus, in the video-disc apparatus 1, the so-called pulse-train
technique is adopted to record a result of image pickup onto the
optical disk 2. In the case of a phase-change disk or the like used
as the optical disk 2, on the other hand, the optical pickup 33
builds up the optical quantity of the laser beam radiated to the
optical disk 2 from a reproduction-time optical quantity to a
recording-time one in accordance with data output by the data
modulator/demodulator 23. Thus, in this case, thermal recording
technique is adopted to record a result of image pickup onto the
optical disk 2.
[0048] In the operations carried out in the video-disc apparatus 1
as described above, the video coder 11 codes a video signal
representing a result of image pickup in order to compress the
signal and convert the compressed signal into a video elementary
stream. By the same token, the audio coder 12 codes an audio signal
representing the result of image pickup in order to compress the
signal and convert the compressed signal into an audio elementary
stream. Then, the file generator 15 converts the video elementary
stream and the audio elementary stream into a data array of a
fragment movie file. Subsequently, the file generator 15 supplies
the data array of the fragment movie file to the optical pickup 33
or the optical pickup 33 as well as the magnetic head 32 by way of
the memory controller 18, the error correction coder/decoder 21 and
the data modulator/demodulator 23, which sequentially process the
data array. Finally, the data array of the fragment movie file is
recorded onto the optical disk 2.
[0049] In a reproduction process, on the other hand, in the
video-disc apparatus 1, the data modulator/demodulator 23 processes
a reproduced signal obtained from the optical pickup 33 in order to
generate reproduced data. Then, the error correction coder/decoder
21 processes the reproduced data in order to reproduce a fragment
movie file recorded on the optical disk 2. Subsequently, the memory
controller 18 outputs the data of the fragment movie file.
[0050] The file decoder 16 receives the data of the fragment movie
file from the memory controller 18, splitting the data into an
elementary stream of video data and an elementary stream of audio
data as outputs. In the processing carried out to generate the
elementary stream of video data and the elementary stream, the file
decoder 16 acquires management information set in an initial moov
atom and management information set in moof atoms, outputting the
pieces of aforementioned management information to the system
control microcomputer 19 in accordance with seek and other control
executed by the system control microcomputer 19. Then, the system
control microcomputer 19 executes control based on the management
information set in the initial moov atom and based on the data of
the moof atoms, driving the file decoder 16 to generate the
elementary stream of video data and the elementary stream of audio
data on the basis of these pieces of management control.
[0051] A video decoder 13 is a section for carrying out a data
decompression process on the video-data elementary stream received
from the file decoder 16 and outputs a result of the process to
display means and an external apparatus, which are not shown in the
figure. By the same token, an audio decoder 14 is a section for
carrying out a data decompression process on the audio-data
elementary stream received from the file decoder 16 and outputs a
result of the process to audio output means and an external
apparatus, which are not shown in the figure. In this way, the
video-disc apparatus 1 generates an image pickup result reproduced
from the optical disk 2 as output signals that can be
monitored.
[0052] The system control microcomputer 19 is a microcomputer for
controlling operations of the whole video-disc apparatus 1. By
execution of predetermined processing programs stored in a memory
not shown in the figure, the system control microcomputer 19
controls the operation of every section employed in the video-disc
apparatus 1 in accordance with an operation carried out by the
user. Thus, the system control microcomputer 19 records a result of
image pickup on the optical disk 2, reproduces a result of image
pickup from the optical disk 2 in order to present the result to
the user and further carries out an edit process.
[0053] It is to be noted that processing programs to be executed by
the system control microcomputer 19 are installed in advance in
this video-disc apparatus 1. Instead of providing the processing
programs to the user by installation of processing programs in
advance, however, the programs can be presented to the user by
recording them on another recording medium. By the way, as the
other recording medium used for recording processing programs to be
provided to the user, it is possible to use one of a wide variety
of recording mediums including an optical disc, a magnetic disk,
memory card and a magnetic tape.
(1-2) Fragment Movie Files
[0054] FIG. 3 is a conceptual diagram showing a basic configuration
of pieces of sample information provided in the initial moov atom
of a fragment movie file. These pieces of sample information are,
each management information used for controlling movie data atoms
of the fragment movie file. It is to be noted that, in the
following description, each atom of a QT movie file is properly
denoted by a type name set in the atom as a type name written in
alphabetical letters.
[0055] The fragment movie format is one of formats taking the
format of the QT movie file as a base. The QT format is a file
format created as an extension function, which is provided to an OS
(Operating System) as extension function for reproducing moving
pictures and the like without using special hardware. The format of
the QT movie file is a time-base multimedia file format usable for
reproducing real data which has a variety of forms including moving
pictures, sounds, still pictures, characters and MIDI by
synchronization of the forms along one time axis. The format of the
QT movie file can also be adapted to streaming through a
network.
[0056] Much like the ordinary QT movie file, in a fragment movie
file, real data including a variety of forms is stored in movie
data atoms as individual tracks.
[0057] As shown in FIG. 1, in a fragment movie file, a set of
tracks containing real data is divided into blocks arranged along
the time axis. Each of the blocks forms a movie data atom.
Management information is assigned to each of the movie data atoms
each serving as a block unit. The atom of management information
for the head block is the initial moov atom. Management information
provided for subsequent blocks following the head block is set in
moof atoms each associated with one of the subsequent blocks. It is
to be noted that an atom is also referred to as a box in some
cases. A movie data atom is an atom with type name mdat. A movie
data atom is also referred to as media data atom.
[0058] The initial moov atom is configured to form a hierarchical
structure, in which management information is divided into boxes
each associated with an attribute, in the same way as the movie
atom in the ordinary QT format. That is to say, the initial moov
atom has a structure including a movie header atom used for
accommodating header information and track atoms used for holding
management information for a track corresponding to a movie data
atom. The track atoms form an stbl atom.
[0059] Pieces of management information on samples are set in the
stbl atom. The stbl atom includes an stts atom, a ctts atom, an
stsz atom, an stsc atom, an stco atom, an stss atom and an stsd
atom.
[0060] The stts atom is an atom used for describing a relation
between samples and the length of a time period of a decoding
process. The length of the time period is expressed in terms of
frames. To put it concretely, the stts atom describes a sample
duration and a sample count. The sample duration is the display
time of each sample. The sample count is the number of samples each
displayed during the sample duration. In an example shown in FIG.
4, the stts atom describes that each of six samples assigned to the
movie data atom associated with the initial moov atom is displayed
during a period of 1,000 units of a time scale defined separately.
It is to be noted that, an atom showing concrete values is
explained on the assumption that a block of a movie data atom
includes only one chunk. The explanation based on this assumption
also applies to the example shown in FIG. 4.
[0061] The ctts atom is an atom used for describing composition
times, which are each information on time related to a display of a
picture, due to the fact that there is a picture, the position of
which in the order of a stream obtained as a result of a data
compression process is different from its position in the order on
the display. That is to say, in the case of the example shown in
FIG. 4, for the first one sample, the ctts atom describes that
decoded video data is delayed by a period of 3,000 units of a time
scale defined separately before being output. For the next two
samples, the ctts atom describes that decoded video data is output
without being delayed at all. For the one sample following the two
samples, the ctts atom describes that decoded video data is delayed
and then output in the same way as the first one sample. For the
last two samples, the ctts atom describes that decoded video data
is output without being delayed at all.
[0062] The stsz atom is an atom used for describing sample sizes,
which are each the size of a sample. In the case of the example
shown in FIG. 4, in the configuration of the samples, the first
sample has a size of 5,154 bytes and a sample following the first
sample has a size of 2,087 bytes.
[0063] The stsc atom is an atom used for describing a relation
between each chunk and samples composing the chunk. It is to be
noted that, in this case, a chunk is a block assigned to a movie
data atom as a block resulting from a blocking process carried out
on real data. A chunk is created from one sample or a plurality of
samples. The stsc atom describes information including the number
of the first chunk allocated to the movie data atom associated with
the initial moov atom, the number of samples in each chunk and an
Stsd ID (sample description index) used for identifying information
recorded in the stsd atom as information on a decoding process. The
stsd atom holds information on a decoding process. An example of
the information on a decoding process is a data compression method.
In the example shown in FIG. 4, the number of the first chunk
allocated to the movie data atom associated with the initial moov
atom is one, six samples are assigned to a chunk and the decoding
process adopts the first decoding method described in the stsd
atom.
[0064] The stco atom is an atom used for describing a chunk offset,
which is information on the position of the head chunk in the file.
The position in the file is a position with the beginning of the
file taken as a reference. In the case of the example shown in FIG.
4, the stco atom describes that the first chunk of the movie data
atom associated with the initial moov atom including the stco atom
starts at an offset of 1,000 bytes from the beginning of the
fragment movie file.
[0065] The stss atom is an atom used for describing a sync sample,
which is information identifying which sample is a
random-accessible sample. In this embodiment, the stss atom
describes information on the position of an I picture. In the case
of the example shown in FIG. 4, the stss atom indicates that the
first sample is an I picture.
[0066] FIG. 5 is a table referred to in explanation of sample
information of a moof atom. The sample information shown in this
figure is the sample information of a moof atom following the
initial moov atom, the sample information of which is shown in FIG.
3. A moof atom includes a tfhd atom and a plurality of trun atoms.
The tfhd atom of a moof atom is a head atom in which default values
of the moof atom are set. It is possible to carry out processing on
the basis of the default values set in the tfhd atom of the moof
atom without management information set in the subsequent trun
atoms. Thus, the amount of data can be compressed in a process to
create a fragment movie file.
[0067] Information set in the tfhd atom as the default values
includes a base data offset and a sample description ID. The base
data offset corresponds to the aforementioned chunk offset, which
is position information set in the stco atom of the initial moov
atom. On the other hand, the sample description ID corresponds to
the stsd ID set in the stsc atom of the initial moov atom as an ID
used for identifying information on the decoding process. The base
data offset serving as information on a position is the distance
from the beginning of the file to the beginning of a movie data
atom associated with the moof atom. In a numerical example shown in
FIG. 6, the base data offset is set at 26,700 bytes. In addition,
the example shown in FIG. 6 is used for recording a sample
description ID of one revealing the fact that the decoding process
adopts the first decoding method recorded in the stsd atom, which
serves as a sample description atom of the initial moov atom.
[0068] On top of that, the tfhd atom also includes: a default
sample size corresponding to the sample size set in the stsz atom
of the initial moov atom; a default sample duration corresponding
to the sample duration set in the stts atom of the initial moov
atom; a default sync sample corresponding to the sync sample set in
the stss atom of the initial moov atom as information used for
identifying which sample is a random-accessible sample set in the
stss atom. In addition, in the example shown in FIG. 6, the default
sample size serving as the default value of the size of the sample
is set at 0. The default sample duration serving as the default
display time of one sample is set at 1,000 units of a time scale
defined separately. The default sync sample serving as information
used for identifying which sample is a random-accessible sample is
set at a value of `nosync` meaning that there is no
random-accessible sample.
[0069] Even though the trun atom is generally provided as an atom
associated with a chunk, the trun atom does not necessarily have to
be associated with a chunk. In the case of a trun atom not
associated with a chunk, a base data offset set in the trun atom as
information on the position of the head chunk associated with the
trun atom has a value other than 0. In the case of this embodiment,
however, the trun atom is provided as an atom associated with a
chunk. The data offset set in such a trun atom is information on
the position of a chunk associated with the trun atom. The data
offset set in the trun atom is a value taking the base data offset,
which is set in the tfhd as information on a position, as a
reference. Since the trun atom in the example shown in FIG. 6 is an
atom for the head chunk associated with this moof atom, the data
offset included in the trun atom as information on a position is
set at 0.
[0070] In addition to the data offset, the trun atom includes a
table set provided for samples. For each of the samples, the table
shows pieces of information consisting of a sample size, a sample
duration and a sync sample indicating whether or not the sample is
a random-accessible sample, which correspond to respectively the
default sample size, sample duration and sync sample set in the
tfhd atom. On top of that, the information shown by the table also
includes a composition time as information on the same display time
as that of the initial moov atom. Thus, in the example shown in
FIG. 6, a table showing information on six samples is created in
the trun atom. The table includes the size of each sample. The size
of a sample is value taking the default sample size as a reference.
Each sample is displayed during a `none` sample duration, which is
the default sample duration of 1,000 units. The table also reveals
the fact that only the first sample at the left end of the table is
a random-accessible sample. The table also shows that only the
first and fourth samples have a composition time of 3,000 units to
indicate that, for each of these samples, the output of a decoding
process is delayed by the composition time.
[0071] As described above, in the case of the fragment movie file,
every moof atom includes information on the position of each of
chunks associated with the moof atom, the size of each of samples
included in every chunk, the display time of each sample and
identification information provided for each sample as information
used for indicating whether or not the sample is a
random-accessible sample. The information on the position of each
chunk, the size of each sample, the display time of each sample and
the identification information are each set in the moof atom as a
relative setting, which takes a standard setting set for the block
associated with the moof atom as a reference. On the other hand,
information set in the initial moov atom is settings corresponding
to the standard settings set in each moof atom. It is thus
necessary to reproduce real data by switching processing from the
initial moov atom to a moof atom. The need to switch the processing
complicates a process to reproduce a fragment movie file.
(1-3) Processing of the System Control Microcomputer
[0072] The system control microcomputer 19 controls whole
operations so as to assign coded data of a frame to a sample, set a
chunk from a predetermined number of samples and create a movie
data atom from a plurality of chunks. Subsequently, the system
control microcomputer 19 controls whole operations so that, for
these movie data atoms, an initial moov atom and moof atoms are
created as management-information atoms with the formats shown in
FIGS. 3 to 6 and these movie data atoms and management-information
atoms are then recorded sequentially onto the optical disk 2. As a
result, the result of image pickup is recorded onto the optical
disk 2 as a fragment movie file. It is to be noted that audio data
is also allocated to movie data atoms each corresponding to an
audio track. Then, for these movie data atoms, an initial moov atom
and moof atoms are created as management-information atoms also
corresponding to an audio track.
[0073] In a process to reproduce a fragment movie file of a
recorded image pickup result from the recording medium 2, on the
other hand, the system control microcomputer 19 modifies management
information set in moof atoms obtained as a result of reproduction
from the optical disk 2 to records compatible with the initial moov
atom and stores the modified management information in an embedded
memory. Then, in accordance with the records stored in the embedded
memory, movie data atoms are reproduced from the optical disk
2.
[0074] FIG. 7 is a table referred in comparison with the table
shown in FIG. 4 in explanation of processing to modify management
information set in a moof atom shown in FIG. 6. In actuality, the
system control microcomputer 19 holds management information
detected from the initial moov atom as management information
necessary for a variety of reproduction processes in a tabular
format in the embedded memory. Then, the system control
microcomputer 19 modifies management information held in the
embedded memory to management information compatible with the
management information set in the initial moov atom also held in
the embedded memory in the tabular format and adds the modified
management information to the management information set in the
initial moov atom, storing a result of the addition in the memory.
After all, this processing is processing to modify management
information set in every moof atom to management information
compatible with the initial moov atom. For this reason, in the
following description, management information set in the initial
moov atom explained earlier by referring to FIG. 3 is referred to.
Concrete values set in the initial moov atom and a moof atom are
explained by referring to setting shown in FIGS. 4 and 6
respectively.
[0075] To put it concretely, the system control microcomputer 19
carries out processing to transform management information set in a
moof atom from relative values into absolute values as follow.
First of all, the system control microcomputer 19 modifies
management-information values set for the moof atom as relative
values taking the default management-information values of the
initial moov atom as references to absolute management-information
values not taking the default management-information values as
references. The system control microcomputer 19 then stores the
absolute management-information values obtained a result of the
modification into the embedded memory as values compatible with the
default management-information values of the initial moov atom.
[0076] That is to say, in the example shown in FIG. 4, the stts
atom of the initial moov atom shows a sample duration of 1,000 for
each of six samples. In the example shown in FIG. 6, on the other
hand, the tfhd atom of the moof atom includes a default sample
duration of 1,000 for a sample. The table of the first trun atom
shows that the sample duration of each of the six samples has a
value of `none` indicating that the default sample duration is
adopted, The values of moof atom set in the first trun atom are
modified to values compatible with the values set in the initial
moov atom and added to the table set in the initial moov atom to
give a result shown in FIG. 7. As shown in the figure, the stts
atom shows a sample duration of 1,000 for each of 12 samples. The
values included in the stts atom of the initial moov atom shown in
the figure are a result of the processing carried out by the system
control microcomputer 19 to modify the values set in the table of
the trun atom as values based on the default sample duration set in
the tfhd atom and add the modified values to the stts atom. The
stts atom includes a sample count and a sample duration.
[0077] On the other hand, the ctts atom of the initial moov atom
shown in FIG. 4 shows an array of composition times starting with
the composition time of the first sample to be followed
sequentially by those of the subsequent samples. As for the moof
atom shown in FIG. 6, the first trun atom shows composition times
of 3000, 0, 0, 3000, 0 and 0 for six samples respectively. These
composition times are added to the ctts table as sample counts of
1, 2, 1 and 2 associated with composition times of 3000, 0, 3000
and 0 respectively. In this way, the system control microcomputer
19 adds composition times recorded in the table of the trun
atom.
[0078] As shown in FIG. 6, sample sizes include a default sample
size of 0 in the tfhd atom of the moof atom and sample sizes
recorded in the table of the trun atom of the moof atom in a way
compatible with the sample sizes recorded in the initial moov atom
shown in FIG. 4. Thus, in this case, the system control
microcomputer 19 adds the sample sizes recorded in the table of the
trun atom of the moof atom.
[0079] The stsc atom shown in FIG. 4 includes a first chunk of 1, a
sample per chunk of 6 and an stsd ID of 1. The first chunk is a
number assigned to the first chunk. The samples per chunk is the
number of samples composing each chunk. The stsd ID is an ID used
for identifying information on a decoding process. As shown in FIG.
6, on the other hand, the tfhd atom of the moof atom includes a
sample description ID of 1 as an ID used for identifying
information on a decoding process. In addition, the trun atom
indicates six sets of information for six samples included in a
chunk associated with the trun atom. Thus, the stsd atom is held as
it is without adding any information to the atom. In this case,
however, if the type of the decoding process is modified in the
course of the process, that is, if the number of samples composing
a chunk changes, for example, the system control microcomputer 19
changes the stsd atom by setting the chunk number of the new chunk
in the first-chunk number, the number of samples in the samples per
chunk and a new ID in the stsd ID used for identifying information
on a decoding process.
[0080] In the example shown in FIG. 4, the chunk offset, which is
information on the position of the first chunk, is set at 10,000
bytes. In the example shown in FIG. 6, on the other hand, the base
data offset in the tfhd atom is set at 26,700 bytes and, in the
first trun atom, the data offset is set at 0 byte. Thus, a chunk
offset of 26,700 bytes is added to the stco atom. The chunk offset
added to the stco atom is the sum of the aforementioned base data
offset of 26,700 bytes in the tfhd atom and the aforementioned data
offset of 0 byte in the first trun atom.
[0081] The stss atom in the example shown in FIG. 4 describes a
sync sample, which is information indicating that the head sample
is a random-accessible sample. While six samples are assigned to
this initial moov atom, the table of the following first trun atom
includes a sync sample only for the first sample to indicate that
only the first sample is a random-accessible sample as shown in
FIG. 6. For this reason, information indicating that the seventh
sample is a random-accessible sample is added to the stss atom.
That is to say, in this case, the system control microcomputer 19
adds the number of the random-accessible sample to the stss atom on
the basis of the sync sample information recorded in the trun
atom.
[0082] In order to carry out the addition processes described
above, the system control microcomputer 19 must modify settings of
each moof atom serving as management information set in the
following block to settings compatible with the initial moov atom,
which is the management information set in the head block.
[0083] When the user enters an instruction to start a process to
reproduce a result of image pickup, the system control
microcomputer 19 issues a command to start a process to reproduce a
fragment movie file of the result of image pickup. In this case,
the initial moov atom of the fragment movie file is reproduced from
the optical disk 2 and held in an embedded memory. Then, on the
basis of the initial moov atom held in the embedded memory, the
corresponding movie data atom are reproduced from the optical disk
2 to be presented to the user. During a free time period in an
access to the optical disk 2 to reproduce the movie data atom, the
following moof atom is reproduced from the optical disk 2. Finally,
management information recorded in each of the moof atoms is
modified to settings compatible with the initial moov atom and
added to the settings of the initial moov atom to produce new
settings, which are also stored in the embedded memory.
[0084] The system control microcomputer 19 concurrently carries out
the process to reproduce the movie data atom, the process to
reproduce moof atoms, the process to modify management information
recorded in each of the moof atoms to settings compatible with the
initial moov atom and the process to add the modified management
information to the settings of the initial moov atom in order to
produce new settings. In this way, while reproducing the fragment
movie file, the system control microcomputer 19 modifies all moof
atoms provided in the fragment movie file to settings compatible
the initial moov atom, adds the modified management information to
the settings of the initial moov atom in order to produce new
settings and stores the new settings in the embedded memory.
[0085] Thus, the system control microcomputer 19 bears a heavier
processing load only temporarily. This is because any subsequent
process to reproduce the same fragment movie file and a process to
reproduce the fragment movie file between an operation to modify
settings of all moof atoms and an operation to store the modified
settings in an embedded memory (that is, a process to reproduce
real data left in the fragment movie file as real data associated
with a range of the stored modified settings) can be carried out
without switching the processing from the initial moov atom to a
moof atom. The elimination of the need to switch the processing
simplifies the process to reproduce the fragment movie file.
[0086] That is to say, in the same way as the process to reproduce
an ordinary QT movie file, on the basis of modified management
information set in moof atoms stored in the embedded memory as a
result of a process to modify the management information to
settings compatible with the initial moov atom as described above,
the system control microcomputer 19 sequentially reproduces samples
associated with management information set in the moof atoms in a
process to reproduce a fragment movie file containing the samples
in a direction along the time axis. In addition, in response to an
operation carried out by the user, the identification information
(referred to as sync sample) included in the management information
stored in the embedded memory as described above as information
identifying which sample is a random-accessible sample is used for
selectively reproducing a sample included in a movie data atom as a
sample containing real data. By selectively reproducing such a
sample, the fragment movie file can be reproduced at a variable
speed. In addition, a chunk offset included in the same management
information as information on a position is used for detecting a
reproduction time and a process to reproduce samples of movie data
atoms is started at the detected reproduction time. By starting the
process to reproduce samples of movie data atoms at a detected
reproduction time, a process to reproduce the fragment movie file
can be started at a reproduction time indicated by the position
information (or the chunk offset).
[0087] If the storage capacity of the embedded memory is not large
enough for storing the modified management information set in all
moof atoms in the same format as the initial moov atom, a work area
of the optical disk 2 is allocated to the modified management
information to compensate the embedded memory for the
insufficiency. In this case, the modified management information
set in all moof atoms is acquired in the same format as the initial
moov atom and temporarily stored in the work area allocated in the
optical disk 2. As the process to reproduce the fragment movie file
is ended, an absolute path pointing to movie data atoms of the
fragment movie file is set. Then, movie atoms of an ordinary QT
movie file are created as atoms containing the management
information stored in the work area allocated in the optical disk 2
and recorded on the optical disk 2. In this way, a QT movie file
having an external reference format can be created.
[0088] Then, a file name assigned to the QT movie file created as
described above is set in the name of the fragment movie file
reproduced so far and the extension of the new file name of the
reproduced fragment movie file is modified to a file name extension
indicating that the reproduced fragment movie file is a QT movie
file. That is to say, the file name of the newly created QT movie
file points to the fragment movie file indicated by the file name
with a modified extension.
[0089] Thus, once the management information set in moof atoms has
been modified to a format compatible with the initial moov atom,
the system control microcomputer 19 is capable of effectively
utilizing the modified management information included in the
modified moof atoms to reproduce the fragment movie file in any
subsequent process. In any subsequent process to reproduce the
fragment movie file, the moof atoms no longer need to be modified.
Instead, by carrying out the same process as a process to reproduce
an ordinary QT movie file, movie data atoms of the fragment movie
file can be reproduced.
(2) Operations of the Embodiment
[0090] In the video-disc apparatus 1 having the configuration
described above, a video signal taken by the image pickup means is
subjected to a data compression process carried out by the video
coder 11 in order to convert the signal into coded data. The coded
data is then supplied to the file generator 15. At the same time,
an audio signal taken by the image pickup means is subjected to a
data compression process carried out by the audio coder 12 in order
to convert the signal into coded data. By the same token, the coded
data is also supplied to the file generator 15. Then, the file
generator 15 creates a sample including coded data of the video and
audio signals for each frame of the video signal. The file
generator 15 further creates a chunk from each plurality of
aforementioned samples. The coded data is finally, recorded onto
the optical disk 2 by way of the memory controller 18, the error
correction coder/decoder 21 and the data modulator/demodulator 23
in block units each composing a plurality of aforementioned chunks.
In addition, while the block units each composing a plurality of
aforementioned chunks are being recorded onto the optical disk 2,
information including management information is obtained for each
of the blocks as information used for reproducing the block units
from the optical disk 2. The management information is used by the
system control microcomputer 19 and the file generator 15 to create
a data array composed of an initial moov atom and moof atoms. The
data array is also recorded onto the optical disk 2 by the same
recording system as the coded data.
[0091] Thus, in the video-disc apparatus 1, video data represented
by the video signal, which is a signal of real data, is segmented
into blocks each including a plurality of aforementioned chunks.
Management information associated with each of blocks following the
head block of the real data, that is, management information
associated with each of blocks other than the head block, is stored
in a moof atom. The management information stored in a moof atom
associated with a block includes position information of each of
the chunks, the size of each sample, the display duration of each
sample and identification information indicating whether or not a
sample is a random-accessible sample. The position information, the
sample size, the sample display duration and the sample
identification information are each a setting to be recorded on the
optical disk 2 as a setting relative to a reference, which is
described in the tfhd atom for the block as a standard setting. On
the other hand, management information for the head block of the
real data is included in the initial moov atom for every chunk
associated with the initial moov atom and each of samples included
in every chunk as settings, which are to be recorded on the optical
disk 2 as settings corresponding to the standard settings described
in the aforementioned tfhd atom of every moof atom. That is to say,
a result of image pickup is recorded onto the optical disk 2 as a
fragment movie file including blocks of real data and pieces of
management information associated with the blocks.
[0092] Thus, in the video-disc apparatus 1, even if an operation to
take an image can no longer be continued due to typically a failure
occurring in the course of the image pickup operation, a result of
the image pickup operation carried out so far can be recorded on
the optical disk 2 as data that can be reproduced from the optical
disk 2.
[0093] In a process to reproduce an image pickup result recorded on
the optical disk 2 as described above, however, the processing of
the process must be switched from the initial moov atom to a moof
atom in order to acquire management information recorded in these
atoms as management information required in the reproduction
process. In order to solve this problem of this process switching,
when the user enters an instruction to start a process to reproduce
an image pickup result recorded on the optical disk 2, the
video-disc apparatus 1 starts a process to reproduce a fragment
movie file containing the result of image pickup from the optical
disk 2. In the process to reproduce the fragment movie file from
the optical disk 2, first of all, the initial moov atom is
reproduced and the management information included in the initial
moov atom is held in an embedded memory. Then, on the basis of the
management information held in the embedded memory as the
management information set in the initial moov atom, a movie data
atom associated with the initial moov atom is reproduced from the
optical disk 2 and presented to the user. During a free time period
in an access to the optical disk 2 to reproduce this movie data
atom, the following moof atom is reproduced from the optical disk
2. The video-disc apparatus 1 then modifies the management
information included in the moof atom reproduced in this way on the
basis of standard settings set in the moof atom to management
information compatible with management information held in the
embedded memory as management information set in the initial moov
atom, and adds the modified management information to the
management information held in the embedded memory.
[0094] Even after the management information set in the moof atom
is acquired in this way, the video-disc apparatus 1 concurrently
carries out a process to reproduce a movie data atom associated
with the acquired moof atom, a process to reproduce the next moof
atom, a process to modify management medium included in the next
moof atom to management information compatible with the settings in
the initial moov atom and a process to add the modified management
information to the settings stored in the embedded memory as the
settings in the initial moov atom at the same time. Thus, while the
fragment movie file is being reproduced from the optical disk 2,
the management information set in all moof atoms set in the
fragment movie file is modified to management information
compatible with the settings in the initial moov atom.
[0095] As a result, in the video-disk apparatus 1, the system
control microcomputer 19 bears a heavier processing load only
temporarily when a fragment movie file is reproduced for the first
time. This is because any subsequent process to reproduce the same
fragment movie file can be carried out without switching the
processing from the initial moov atom to a moof atom. The
elimination of the need to switch the processing simplifies the
process to reproduce the fragment movie file. In addition, a
process to reproduce the fragment movie file between an operation
to modify settings of all moof atoms and an operation to store the
modified settings in an embedded memory (that is, a process to
reproduce real data left in the fragment movie file as real data
associated with a range of the stored modified settings) can be
carried out without switching the processing from the initial moov
atom to a moof atom. Thus, by the same token, the elimination of
the need to switch the processing simplifies the process to
reproduce the fragment movie file.
[0096] As described above, real data recorded on the optical disk 2
is reproduced on the basis of management information stored in the
embedded memory. Thus, much like a process to reproduce an ordinary
QT movie file, samples of each movie data atom of the fragment
movie file can be reproduced sequentially along the time axis. In
addition, in accordance with identification information included in
management information held in the embedded memory for a sample as
identification information used for indicating whether or not the
sample is a random-accessible sample, samples each included in a
movie data atom as a sample containing real data can be reproduced
selectively. Thus, the fragment movie file can be reproduced at a
variable speed.
[0097] If the storage capacity of the embedded memory is not large
enough for storing the modified management information set in all
moof atoms in the same format as the initial moov atom, the
video-disc apparatus 1 allocates a work area of the optical disk 2
to the modified management information to compensate the embedded
memory for the insufficiency. Thus, even in the case of a fragment
movie file obtained as a result of a long recording process and
even in the case of a memory embedded in the system control
microcomputer 19 as a memory with a small storage capacity, the
management information included in moof atoms of the fragment movie
file can be modified to management information compatible with
settings in the initial moov atom of the same file with a high
degree of reliability.
[0098] Then, the management information set in all moof atoms is
acquired in the same format as the settings in the initial moov
atom and temporarily recorded in the work area allocated in the
optical disk 2. As the process to reproduce the fragment temporary
file is completed, the management information held in the allocated
work area is used for recording a QT movie file with an external
reference format onto the optical disk 2. Then, by modifying the
file name, the QT movie file can be used as a substitute for the
fragment movie file.
[0099] Thus, once management information set in the moof atoms has
been modified to a format compatible with the initial moov atom,
the video-disc apparatus 1 is capable of effectively utilizing the
management information included in the modified moof atoms to
reproduce the fragment movie file in any subsequent process. In any
subsequent process to reproduce the fragment movie file, the moof
atoms no longer need to be modified. Instead, by carrying out the
same process as a process to reproduce an ordinary QT movie file,
movie data atoms of the fragment movie file can be reproduced.
(3) Effects of the Embodiment
[0100] In accordance with the embodiment described above,
management information set in blocks following the head block is
modified to management information compatible with management
information set in the head block in a process to reproduce real
data of the blocks. It is thus possible to simplify the process to
reproduce a fragment movie file or the like containing the real
data.
[0101] To put it more concretely, in this case, the real data is
video data and the management data for managing reproduction of the
real data is provided for each sample, which corresponds to a frame
of the video data. Thus, the present invention can be applied to
reproduction of typically a fragment movie file, which has the ISO
base media file format taking the QT movie file format as a base,
in order to make the processing of the reproduction process
simple.
[0102] In addition, the management information includes
identification information provided for a sample as information
indicating whether or not the sample is a random-accessible sample.
Thus, on the basis of the identification information kept in the
modified management information, the real data can be selectively
reproduced. As a result, by carrying out a simple process in the
same way as the process to reproduce an ordinary QT file, the real
data can be reproduced at a variable speed.
[0103] On top of that, the management information includes position
information corresponding to a reproduction time of the real data.
Thus, on the basis of the position information kept in the modified
management information, a process to reproduce the real data can be
started. As a result, by carrying out a simple process in the same
way as the process to reproduce an ordinary QT file, the process to
reproduce the real data can be commenced at a reproduction time
identified by the position information.
[0104] The management information modified as described above is
recorded onto an optical disk serving as a recording medium. Then,
on the basis of the modified management information recorded on the
recording medium, a file having an external reference format is
created on the recording medium as a file, which references the
real data of the fragment movie file. Thus, subsequent processes to
reproduce the real data can be made simple. In addition, the
fragment movie file can be converted into a file reproducible in a
reproduction apparatus having no function to reproduce a fragment
movie file.
(4) Second Embodiment
[0105] FIG. 8 is a table referred to in comparison with the table
shown in FIG. 7 in explaining processing of management information
used in accordance with a second embodiment of the present
invention. A video-disk apparatus according to the second
embodiment has a configuration identical with the configuration of
the video-disc apparatus 1 according to the first embodiment except
that the second embodiment has management-information processing
different from that of the first embodiment. For this reason, the
second embodiment can be described by referring to the
configuration shown in FIG. 2 as follows.
[0106] In this embodiment, the system control microcomputer 19 is
designed as a microcomputer having an embedded memory with a small
storage capacity. Also in the case of this embodiment, management
information set in moof atoms is modified to information compatible
with the initial moov atom. However, modified management
information for only a plurality of blocks can be stored in the
embedded memory having a small storage capacity as described above.
Thus, the modified management information set in moof atoms is
stored in the embedded memory in a format shown in FIG. 8. This
format allows management information to be deleted from the
embedded memory at the end of the reproduction process so as to
preserve a memory area occupied by the deleted management
information as a free memory area. The deleted management
information is management information no longer required after
completion of a process to reproduce the block data associated with
the management information. Then, management information associated
with the next moof atom as management information to follow
management information left in the embedded memory as management
information for the initial moov atom is modified to information
compatible with settings in the initial moov atom and recorded in
the preserved free memory area. In this way, the video-disc
apparatus 1 is capable of reproducing a fragment movie file by
carrying out a simple process even if the storage capacity of the
embedded memory is extremely small in comparison with the size of
the fragment movie file.
[0107] In addition, in the case, the system control microcomputer
19 carries out a process to delete management information from the
embedded memory in block units each corresponding to a movie data
atom in order to make management of the embedded memory simple. In
order to allow management information to be deleted from the
embedded memory in block units by carrying out a simple process,
modified management information is also recorded into the memory in
block units.
[0108] That is to say, the system control microcomputer 19 records
a sample count and a sample duration in an stts atom for each block
in the embedded memory as shown in FIG. 8 and FIG. 7, which is
given in this case a figure to be compared with FIG. 8. The chunk
offset serving as information on the position of the head chunk of
a block is also recorded in the stco atom for each block.
[0109] Since some management information is information related to
a sample or some samples of a chunk pertaining to a block, recorded
sample information includes boundary information showing a boundary
between blocks. Thus, management of block units can be made simple.
The system control microcomputer 19 records this boundary
information in fragment info showing a chunk count (Chunk Num)
representing the number of chunks included in each block. That is
to say, in the case of an example shown in FIG. 8, every block
includes only one chunk. Thus, the sample counts provided for two
blocks in the stts atom show that every block consists of six
samples. The ctts atom includes sample counts and composition
times. In this ctts atom, a sample-count sum of six provides a
boundary between two adjacent blocks as shown by a dashed line. By
the same token, the stsz atom includes sample sizes and a set of
six sample sizes is separated from another set by a boundary
between blocks as shown by a dashed line. In the same way, the stss
atom includes a sample number assigned to each sync sample as
information indicating which sample is a random-accessible sample.
These numbers assigned to sync samples are also separated from each
other by a boundary between blocks as shown by a dashed line.
[0110] In addition, as shown in FIG. 9 in comparison with FIG. 8,
each time a process to reproduce management information for a block
is completed in the course of the processing to reproduce real
data, the system control microcomputer 19 deletes management
information associated with the block and records the next
management information modified to management information
compatible with the settings of the initial moov atom into the
embedded memory as additional management information following the
remaining management information left in the embedded memory. In
order to reflect the fact that the management information
associated with the block has been deleted from the embedded memory
and the additional management information has been newly recorded
in the embedded memory, the information on a boundary between
blocks in the fragment info is updated.
[0111] As described above, the fragment info set by the system
control microcomputer 19 is information, used for identifying
blocks, the management information set in which is held in the
embedded memory in the management of block units. To put it
concretely, for each block, the management information set in which
is held in the embedded memory, the fragment info set by the system
control microcomputer 19 includes the number of the top chunk in
the block and the number of the top sample in the top chunk in
addition to a top media time representing the display time of the
head block.
[0112] Thus, since the system control microcomputer 19 manages
pieces of management information in block units as described above,
the system control microcomputer 19 is capable of identifying the
present positions of the pieces of management information in the
embedded memory with ease. On the basis of management information
at the present positions, the system control microcomputer 19 is
capable of carrying out processing such as a process of skipping to
a reproduction position specified by the user and, in addition,
capable of carrying out the so-called post-rewind reproduction
processing.
[0113] The so-called post-rewind reproduction processing is
explained as follows. A fragment movie file F1 is reproduced
sequentially in a direction shown by an arrow A in FIGS. 10A and
10B, starting with the management information associated with the
first block shown as fragment #1 in the figure. In the case of an
embedded memory M having a storage capacity for accommodating only
two blocks, as the process to reproduce the management information
associated with the first block is completed, the management
information associated with the first block is deleted from the
embedded memory M to result in a free area occupied so far by the
deleted management information. Then, management information
associated with the third block is stored in the free area. Then,
if the processing to reproduce the fragment movie file F1 is
returned to the reproduction position corresponding to the first
block as shown by an arrow B in FIGS. 11A and 11B with the
management information set in the third block left in the embedded
memory M as it is, however, the management information once stored
in the embedded memory M as the management information associated
with the third block is deleted from the memory M and the
management information associated with the first block is stored
back in the embedded memory M. In this case, the management
information associated with the first block is the management
information included in the initial moov atom. Then, in accordance
with the management information stored back in the embedded memory
M, the first block is reproduced. In this case, on the basis of the
fragment information held in the embedded memory M, the system
control microcomputer 19 is capable of identifying the first block
and storing back the management information associated with the
first block in the embedded memory M. In this way, processing
carried out by the system control microcomputer 19 can be made
simple. As described above, for each block, the management
information set in which is held in the embedded memory, the
fragment info includes the number of the top chunk in the block and
the number of the top sample in the top chunk in addition to the
top media time representing the display time of the first
block.
[0114] FIG. 12 shows a flowchart representing a procedure executed
by the system control microcomputer 19 as a procedure of processing
to reproduce a fragment movie file. At a step SP1, the system
control microcomputer 19 starts the processing procedure in
accordance with an instruction received from the user as a command
to reproduce the fragment movie file. Then, in this case, at the
following step SP2, the system control microcomputer 19 reproduces
the initial moov atom of the fragment movie file and stores the
atom in the embedded memory as a movie resource. Subsequently, the
flow of the processing goes on to the next step SP3 to produce a
result of determination as to whether or not management information
related to a reproduction location requested by the command issued
by the user exists in the embedded memory in accordance with
management information included in the movie resource stored in the
embedded memory. If the result of the determination is a negation,
the flow of the processing goes on from the step SP3 to a step SP4
at which the system control microcomputer 19 finds out the present
position of the management information held in the embedded memory
from the management information stored in the memory. Then, the
system control microcomputer 19 detects the moof atom of a required
block (or a required fragment) from the present position and reads
out the moof atom from the optical disk 2. A process to detect the
moof atom is carried out in accordance with the fragment info
described above.
[0115] Subsequently, at the next step SP5, the system control
microcomputer 19 modifies management information associated with
the moof atom read out from the optical disk 2 to management
information compatible with the structure of the initial moov atom
and stores the modified management information in the embedded
memory. Then, the flow of the processing goes on to a step SP6. If
the determination result produced at the step SP3 is a
confirmation, on the other hand, the flow of the processing goes on
directly to the step SP6. At the step SP6, the system control
microcomputer 19 acquires sample information required in the
reproduction processing from the management information stored in
the embedded memory. Then, at the next step SP7, real data is
reproduced from the optical disk 2 in accordance with this
management information. Subsequently, the flow of the processing
goes on to the next step SP8 to produce a result of determination
as to whether or not the user has instructed the system control
microcomputer 19 to end the reproduction, or whether or not the
tail of the fragment movie file has been reproduced. If the result
of the determination is a negation revealing the fact that the
reproduction processing has not been completed for some reasons,
the flow of the processing goes back to the step SP3. At this and
subsequent steps, the system control microcomputer 19 reads out
sample information associated with the next sample from the
embedded memory if the information has already been stored in the
embedded memory. If the sample information is not found in the
embedded memory, on the other hand, the system control
microcomputer 19 reads out the information from the optical disk 2.
In either case, the reproduction process is continued on the basis
of the sample information. If the determination result produced at
the step SP8 reveals the fact that the reproduction processing has
been completed, on the other hand, the flow of the processing goes
back to a step SP9 at which the system control microcomputer 19
ends the execution of the processing procedure.
[0116] In accordance with the configuration described above, real
data is reproduced from the optical disk 2 in accordance with
management information modified to information compatible with the
management information set in the initial moov atom and stored in
an embedded memory as management information associated with a
plurality of blocks. In the reproduction processing, management
information associated with a block completing a reproduction
process is deleted from the embedded memory, and management
information associated with a next block following the blocks is
modified to information compatible with the management information
set in the initial moov atom and stored in the embedded memory in a
process of managing management information in block units. Thus,
the processing to reproduce a fragment movie file can be made
simple even if the embedded memory has only a small storage
capacity.
[0117] In addition, by also storing boundary information showing
the boundary between every two adjacent blocks in the embedded
memory, it is also possible to simplify the process of managing
management information in block units.
(5) Other Embodiments
[0118] In the embodiments described above, a block consists of a
plurality of chunks. It is to be noted, however, that the scope of
the present invention is not limited to the embodiments described
above. For example, the present invention can also be applied to a
broad range of applications in which a chunk is stretched over two
blocks.
[0119] In addition, in the case of the second embodiment,
management information held in the embedded memory is used only for
reproduction of real data. It is to be noted, however, that the
scope of the present invention is not limited to this second
embodiment. For example, management information held in the
embedded memory can also be used for creation of an ordinary QT
movie file having the external reference format as is the case with
the first embodiment.
[0120] In addition, in the case of the first embodiment, management
information obtained at a reproduction time of a fragment movie
file is also used for creation of a QT movie file having the
external reference format and the QT movie file is used as a
substitute for the fragment movie file. It is to be noted, however,
that the scope of the present invention is not limited to this
first embodiment. For example, in addition to the scheme according
to the first embodiment or as a substitute for the scheme,
typically at a spare time, the initial moov atom of the fragment
movie file and moof atoms of the file are reproduced and used for
creation of an ordinary QT movie file having the external reference
format and the QT movie file is used as a substitute for the
fragment movie file. Additionally, in this case, the fragment movie
file may be reproduced till a middle point in the file and
management information modified to information compatible with
settings in the initial moov atom as management information
associated with moof atoms reproduced so far may be used for
creation of an ordinary QT movie file having the external reference
format. In this way, the time it takes to carry out the work can be
shortened.
[0121] In addition, the embodiments described above each implement
a video-disk apparatus conforming to the formats of the QT file and
ISO base media file. It is to be noted, however, that the scope of
the present invention is not limited to these embodiments. For
example, the present invention can also be applied to a broad range
of apparatus for reproducing files each having a format identical
with the structure of the QT movie file. The formats identical with
the structure of the QT movie file are each a format based on the
format of the QT movie file. Examples of the format based on the
format of the QT movie file are the format a motion JPEG 2000 (MJ2)
file and the format of an AVC (Advanced Video Coding: MPEG-4 part
10) file.
[0122] In addition, in each of the embodiments described, the
present invention provides video-disk apparatus each used for
recording a QT movie file and an ISO media file onto an optical
disk serving as a recording medium. It is to be noted, however,
that the scope of the present invention is not limited to these
embodiments. For example, the present invention can also be applied
to a broad range of applications in which a variety of recording
mediums such as a magnetic disk and a memory card are used as the
recording medium.
[0123] In addition, in each of the embodiments described, the
present invention is applied to a video-disk apparatus. It is to be
noted, however, that the scope of the present invention is not
limited to these embodiments. For example, the present invention
can also be applied to a broad range of apparatus including a
portable telephone having a function for reproducing a moving
picture, a PDA (Personal Digital Assistants), a variety of
reproduction apparatus for reproducing a movie file obtained by
means of wire and radio communications and a variety of editing
apparatus such as personal computers for editing a movie file
obtained as a result of image pickup.
INDUSTRIAL APPLICABILITY
[0124] The present invention can be applied to reproduction of a
fragment movie file typically having an ISO base media file
format.
DESCRIPTION OF REFERENCE SYMBOLS
[0125] 1: VIDEO-DISC APPARATUS [0126] 2: OPTICAL DISK [0127] 11:
VIDEO CODER [0128] 12: AUDIO CODER [0129] 13: VIDEO DECODER [0130]
14: AUDIO DECODER [0131] 15: MEMORY [0132] 16: FILE DECODER [0133]
15A, 17 AND 20: MEMORIES [0134] 18: MEMORY CONTROLLER [0135] 19:
SYSTEM CONTROL MICROCOMPUTER [0136] 21: ERROR CORRECTION
CODER/DECODER [0137] 22: DRIVE CONTROL MICROCOMPUTER [0138] 23:
DATA MODULATOR/DEMODULATOR [0139] 24: MAGNETIC-FIELD MODULATION
DRIVER [0140] 30: SERVO CIRCUIT [0141] 31: SPINDLE MOTOR [0142] 32:
MAGNETIC HEAD [0143] 33: OPTICAL PICKUP
* * * * *