U.S. patent application number 14/845973 was filed with the patent office on 2015-12-31 for apparatus for recording signals on disk recording medium.
The applicant listed for this patent is CANON KABUSHIKI KAISHA. Invention is credited to Hiroaki Endo, Hidenori Hoshi, Toshihiko Suzuki.
Application Number | 20150380057 14/845973 |
Document ID | / |
Family ID | 34623868 |
Filed Date | 2015-12-31 |
United States Patent
Application |
20150380057 |
Kind Code |
A1 |
Suzuki; Toshihiko ; et
al. |
December 31, 2015 |
APPARATUS FOR RECORDING SIGNALS ON DISK RECORDING MEDIUM
Abstract
A recording apparatus of this invention detects the state of
management information, which pertains to a recording address of an
image signal, and which is reproduced from a disk-like recording
medium having a first area for the image signal and a second area
for the management information. On the basis of the detection
result, management data is reproduced from the first area of the
disk-like recording medium. On the basis of the management data
reproduced from the first area, the management information
reproduced from the second area is modified. A modify unit records
the modified management information in the second area.
Inventors: |
Suzuki; Toshihiko;
(Kanagawa-ken, JP) ; Hoshi; Hidenori;
(Nagareyama-shi, JP) ; Endo; Hiroaki;
(Kanagawa-ken, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CANON KABUSHIKI KAISHA |
Tokyo |
|
JP |
|
|
Family ID: |
34623868 |
Appl. No.: |
14/845973 |
Filed: |
September 4, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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|
13827498 |
Mar 14, 2013 |
9154760 |
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14845973 |
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|
12634032 |
Dec 9, 2009 |
8417094 |
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|
13827498 |
|
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|
11100851 |
Apr 7, 2005 |
7684680 |
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12634032 |
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09640301 |
Aug 16, 2000 |
6904229 |
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11100851 |
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Current U.S.
Class: |
386/326 |
Current CPC
Class: |
H04N 5/772 20130101;
H04N 9/8205 20130101; H04N 9/802 20130101; H04N 5/91 20130101; G11B
2220/2525 20130101; H04N 5/85 20130101; G11B 27/329 20130101; H04N
9/8063 20130101; H04N 9/8042 20130101; G11B 27/034 20130101 |
International
Class: |
G11B 27/32 20060101
G11B027/32; H04N 5/91 20060101 H04N005/91; H04N 5/77 20060101
H04N005/77; H04N 5/85 20060101 H04N005/85 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 20, 1999 |
JP |
11/234287 |
Sep 10, 1999 |
JP |
11-257628 |
Oct 26, 1999 |
JP |
11-304137 |
Dec 9, 1999 |
JP |
11-350467 |
Claims
1. A recording apparatus comprising: an obtaining unit configured
to obtain motion image data; a recording unit configured to record
on a recording medium the motion image data obtained by the
obtaining unit and management information relating to recording
address information of data recorded on the recording medium; a
detection unit configured to detect a change between images of two
frames of the motion image data during recording of the motion
image data by the recording unit; and a control unit configured to
control the recording unit to record, in accordance with a
detection result of the detection unit, on the recording medium the
management information relating to recording address information of
the motion image data.
2. The recording apparatus according to claim 1, further
comprising: a reproducing unit configured to reproduce the
management information from the recording medium; and a memory
configured to store the management information reproduced by the
reproducing unit, wherein the control unit updates the management
information stored in the memory in accordance with recording of
the motion image data, and wherein the control unit controls the
recording unit, in accordance with a detection result of the
detection unit, to read the updated management information from the
memory and record on the recording medium the read updated
management information.
3. The recording apparatus according to claim 2, wherein the
reproducing unit reproduces the motion image data from the
recording medium, and wherein the management information is used
for reproducing the motion image data by the reproducing unit.
4. The recording apparatus according to claim 1, further
comprising: an operation unit configured to be used for outputting
a recording start instruction and a recording stop instruction.
5. The recording apparatus according to claim 1, wherein the
detection unit includes a unit for obtaining a difference between
the two frames of the motion image data and a unit for comparing
the difference with a threshold.
6. A recording method comprising: obtaining motion image data;
recording on a recording medium the obtained motion image data and
management information relating to recording address information of
data recorded on the recording medium; detecting a change between
images of two frames of the motion image data during recording of
the motion image data; and controlling to record, in accordance
with a detection result of the detection, on the recording medium
the management information relating to recording address
information of the motion image data.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application Ser. No.
13/827,498, filed Mar. 14, 2013; which is a continuation
application Ser. No. 12/634,032, filed Dec. 9, 2009, which issued
as U.S. Pat. No. 8,417,094 on Apr. 9, 2013; which is a divisional
of application Ser. No. 12/417,903, filed Apr. 3, 2009, which
issued as U.S. Pat. No. 8,526,792 on Sep. 3, 2013; which is a
divisional of application Ser. No. 11/100,851, filed Apr. 7, 2005,
which issued as U.S. Pat. No. 7,684,680 on Mar. 23, 2010, which is
a divisional of application Ser. No. 09/640,301, filed Aug. 16,
2000, which issued as U.S. Pat. No. 6,904,229 on Jun. 7, 2005, the
entire disclosures of which are hereby incorporated by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an apparatus for recording
signals such as image signals on a disk recording medium and, more
particularly, to control of management information of recorded
signals.
[0004] 2. Related Background Art
[0005] Conventionally, a video tape recorder which records analog
video signals on magnetic tapes is available as an image recording
apparatus for recording video signals on a recording medium.
However, with rapid progress of digital signal processing
technologies, digital recording/playback apparatuses which record
analog video signals on recording medium by converting the signals
into digital video signals are becoming popular at present.
[0006] Such digital recording/playback apparatuses include a
digital VTR, a digital video disk apparatus which records signals
on solid-state disk or magnetooptical disk, and a solid-state
memory video apparatus which records signals in a solid-state
memory such as a flash memory or an SRAM.
[0007] These digital recording/playback apparatuses load a video
signal obtained by an image pickup device such as a CCD and convert
the signal into a digital signal by A/D conversion. The apparatuses
reduce the information amount by compression-encoding this digital
video signal. In this manner, these apparatuses can record a large
amount of image information in a small recording capacity.
[0008] Schemes used as this compression encoding are discrete
cosine transform (to be referred to as DCT hereinafter) which is
orthogonal transformation having the highest compression
efficiency, and a variable-length coding scheme. To perform
compression encoding, a single image is first segmented into a
plurality of blocks each having x horizontal pixels and y vertical
pixels, and DCT transform is performed for each block. A DCT
coefficient after the transform is divided by a certain divisor,
and the remainder is rounded, thereby performing quantization. By
using the characteristic that a quantized image is concentrated in
low-frequency components, the number of bits of high-frequency
components is reduced. In this way, the information amount is
greatly reduced.
[0009] The information amount can be further compressed by
performing variable-length encoding, e.g., Huffman coding, which
assigns to the quantized data a code length corresponding to the
occurrence frequency of the data.
[0010] Furthermore, greater compression can be attained by
combining interframe predictive encoding which calculates the
difference between frames, by using the characteristic that a
motion image has a strong correlation between frames.
[0011] Of this type of recording/playback apparatuses, the
capacities of disk media of disk apparatuses are rapidly increasing
in recent years. Consequently, apparatuses which record and play
not only audio signals but video signals in and from a disk medium
for a long time have been proposed. For example, a technique has
been proposed which uses a recording format based on
high-efficiency encoding such as MPEG using, e.g., DCT and
variable-length encoding described above, and which can realize a
recording/playback apparatus which records video signals for one
hour or more at data rates of about 4 Mbps and 10 Mbps.
Furthermore, disk media themselves are being reliably decreased in
size and increased in capacity.
[0012] In an image recording apparatus which records video signals
on a disk medium by reducing the information amount by compressing
the signals by combining the aforementioned compression techniques,
the information amount varies in accordance with an image because
variable-length encoding is used. Therefore, a rate control means
for holding the information amount constant is used to uniformize
the recording rate of images, thereby recording images in a
predetermined recording media capacity within a predetermined
time.
[0013] This rate control uniformizes the rate by writing compressed
data having variations into a certain predetermined buffer and
reading out the data at a constant rate. That is, buffer control is
performed such that if the data may exceed a predetermined value of
the buffer, the quantization level described above is increased to
raise the compression ratio; if the buffer does not satisfy the
predetermined value, the quantization level is decreased to lower
the compression ratio.
[0014] In constant bit rate recording (CBR recording), the
recording rate is held constant by giving priority to the target
time of recording on a recording medium. Hence, if an input image
moves fast or has a wide color band, quantization becomes coarse to
make the image nonuniform between frames. Therefore, an image
recording apparatus which performs variable bit rate recording (VBR
recording) by attaching importance to image quality has been
proposed. This VBR recording performs encoding giving priority to
image quality by holding the quantization level of recording at a
substantially constant value, while allowing fluctuations of the
recording rate.
[0015] A recording/playback apparatus like this uses management
information called Table of Contents (to be referred to as a TOC
hereinafter) to control video data recording and playback
operations. When video data obtained by image pickup is recorded on
a recording medium, the TOC information is recorded in an area
formed on the inner peripheral side of the disk medium
independently of an area for recording video data. In playback
operation, the TOC information is read out from the disk medium and
held in an internal memory of the apparatus. On the basis of this
TOC information, the position of access to the disk medium and
diverse operations such as video data playback management are
controlled.
[0016] Examples of operations managed using the TOC are an
operation of linking data of one scene, which are discontinuously
recorded on a recording medium, and continuously displaying back
the data, an operation of deleting a scene once obtained by image
pickup, and an operation of recording a scene newly obtained by
image pickup in a free space formed by deletion.
[0017] In any of these operations, video data is recorded in an
area (video recording area) formed near the center in the radial
direction of a disk medium, and the TOC information is saved in an
area (system information management area) formed inside the image
recording area. Note that no data can be recorded in the outer
periphery of the. disk.
[0018] Since the TOC is important information necessary to
recording/playback, the reliability is improved by, e.g., recording
the TOC a plurality of times in the system management area of a
disk.
[0019] In conventional image pickup recording/playback apparatuses,
the TOC is recorded on a disk after video data is completely
written in the medium. That is, after the recording end pointer
(address) of video data on a disk is determined, various pieces of
information including an end pointer and start pointer are recorded
as the TOC information.
[0020] If, therefore, one recorded scene extends over a long time
period, no TOC information may be recorded for long periods of
time.
[0021] Also, a system using a disk medium can rapidly access data
in the disk medium, so recording or playback access to the disk
medium is usually intermittently performed. Between this disk
access operation and other operations, large differences are
produced in consumption power such as motor driving power, head
driving power, and write laser power.
[0022] When a series of recording operations are performed with
battery driving, therefore, the battery supply voltage lowers with
an abrupt rise of the consumption power upon disk access. This
sometimes makes the recording operations of the system impossible
to perform.
[0023] Especially when the TOC information is to be recorded, the
write operation is performed by moving a recording/playback head
mechanism from the video recording area for recording video data to
the system management area in a remote position. Hence, if the
battery amount remains to such an extent that a video data
recording operation is marginally possible, the TOC information
cannot be written in the worst case.
[0024] If the TOC information is missing, the start pointer, end
pointer, attribution, and the like of recorded video data are
unknown, so disk medium playback control cannot be performed.
[0025] Also, even if the reliability of the TOC data is improved as
described previously, recording is sometimes abnormally terminated
in the middle of a scene by, e.g., careless handling by a user,
running out or abrupt discharge of a battery, a defect of a
recording medium, or some external cause. In a case like this,
actually recorded images and sounds and additional data sometimes
disagree with the contents of the TOC. This makes playback of the
scene based on the TOC impossible.
SUMMARY OF THE INVENTION
[0026] It is an object of the present invention to solve the above
conventional problems.
[0027] It is another object of the present invention to reliably
record management information such as TOC information on a
recording medium without losing the management information, even
when the remaining battery amount becomes insufficient during image
pickup recording.
[0028] It is still another object of the present invention to
normally reproduce a recorded signal halfway even when recording of
the signal is not normally completed.
[0029] To achieve the above objects, according to one aspect of the
present invention, there is provided a recording apparatus
comprising reproducing means for reproducing management information
pertaining to a recording address of an image signal from a
disk-like recording medium having a first area for the image signal
and a second area for the management information, control means for
detecting the state of the reproduced management information by
using the management information and, on the basis of the detection
result, controlling the reproducing means to reproduce management
data from the first area of the disk-like recording medium,
modifying means for modifying the management information reproduced
from the second area, on the basis of the management data
reproduced from the first area, and recording means for recording
an image signal in the first area of the disk-like recording medium
and recording the management information modified by the modifying
means in the second area.
[0030] Other objects and features of the present invention will
become apparent from the following detailed description of
embodiments of the invention taken in conjunction with the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 is a block diagram showing the configuration of a
recording apparatus according to an embodiment of the present
invention;
[0032] FIG. 2 is a block diagram showing the arrangement of a
recording unit shown in FIG. 1;
[0033] FIG. 3 is a view showing the directory structure of the
apparatus shown in FIG. 1;
[0034] FIG. 4 is a view showing a TOC processed by the apparatus
shown in FIG. 1;
[0035] FIG. 5 is a view showing the major components of an electric
power unit of the apparatus shown in FIG. 1;
[0036] FIG. 6 is a flow chart for explaining an operation of the
apparatus shown in FIG. 1;
[0037] FIG. 7 is a view showing another example of the TOC
processed by the apparatus shown in FIG. 1;
[0038] FIG. 8 is a flow chart for explaining another operation of
the apparatus shown in FIG. 1;
[0039] FIG. 9 is a view showing a recording format on a disk in the
apparatus shown in FIG. 1;
[0040] FIG. 10 is a block diagram showing the configuration of a
recording apparatus according to another embodiment of the present
invention;
[0041] FIG. 11 is a view for explaining picture rearrangement by
the apparatus shown in FIG. 10;
[0042] FIG. 12 is a view for explaining encoding by the apparatus
shown in FIG. 10;
[0043] FIG. 13 is a timing chart showing the recording timings of
TOC data in the apparatus shown in FIG. 1;
[0044] FIG. 14 is a timing chart showing the recording timings of
an image signal in the apparatus shown in FIG. 10;
[0045] FIGS. 15A and 15B are graphs showing a picture change
detection process by the apparatus shown in FIG. 14;
[0046] FIG. 16 is a block diagram showing the configuration of a
recording apparatus according to still another embodiment of the
present invention;
[0047] FIG. 17 is a graph for explaining the operation of an audio
change detection circuit of the apparatus shown in FIG. 16;
[0048] FIG. 18 is a timing chart showing the recording timings of
TOC data in the apparatus shown in FIG. 16;
[0049] FIG. 19 is a block diagram showing the configuration of a
recording apparatus according to still another embodiment of the
present invention;
[0050] FIG. 20 is a view showing a recording format on a disk in
the apparatus shown in FIG. 19;
[0051] FIG. 21 is a view showing recorded data on the disk shown in
FIG. 20; and
[0052] FIG. 22 is a view showing TOC data processed by 5 the
apparatus shown in FIG. 21.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0053] Preferred embodiments of the present invention will be
described in detail below with reference to the accompanying
drawings.
[0054] FIG. 1 is a block diagram showing the configuration of a
recording/playback apparatus 100 according to the first embodiment
of the present invention. Referring to FIG. 1, this
recording/playback apparatus 100 comprises an optical system 101
including, e.g., a lens and a lens controller, an image pickup
processing unit 102, an A/D converter 103, a camera signal
processing unit 104, a video signal processing unit 105, a D/A
converter 106, an analog video signal output unit 107, a display
unit 108, a data bus 109, a memory 110, a memory controller 111, a
CPU 112, a disk unit 113, an electric power unit 114 such as a
battery, and an operation unit 115 including, e.g., a power switch
and a recording trigger switch. For the sake of simplicity, the
electric power unit 114 is connected only to the CPU 112 in FIG. 1.
In reality, however, electric power is supplied to all units
requiring power via power lines.
[0055] In this recording/playback apparatus 100, the optical system
101 including a lens performs iris control, focusing control, zoom
control, and the like. The image pickup processing unit 102
photoelectrically converts an object image (not shown) by a CCD
(Charge-Coupled Device) or the like. The A/D converter 103 converts
the obtained analog image signal into a digital signal. The camera
signal processing unit 104 performs predetermined data processing
such as gamma correction and white balance adjustment for the
digital image data.
[0056] In recording operation, the video signal processing unit 105
segments the output image data from the camera signal processing
unit 104 into a plurality of blocks each composed of a plurality of
pixels, performs orthogonal transformation such as DCT for each
block, and quantizes and encodes the blocks. Generally, a change
between two continuous frames is small in motion image data so an
image of interest has high correlations with images before and
after that image. By using this characteristic, the differences
between an image of interest and images of frames before and after
the image of interest are encoded to perform image compression. An
MPEG scheme is used most frequently by which the difference between
images is obtained after motion compensation is performed to reduce
the redundancy in the time axis, and orthogonal transformation such
as DCT and variable-length coding are performed on the obtained
differential data.
[0057] The image data compressed and encoded by the video signal
processing unit 105 is output to the disk unit 113 and recorded on
a magnetooptical disk, as will be described later.
[0058] In playback operation, image data reproduced by the disk
unit 113 is output to the video signal processing unit 105. The
video signal processing unit 105 performs decoding, which is the
reverse of encoding performed during recording, for the reproduced
image data to expand its information amount, and outputs the
decoded data to the D/A converter 106.
[0059] The D/A converter 106 converts the output digital video
signal from the video signal processing unit 105 into an analog
signal. The video signal output unit 107 converts this analog
signal into a signal following a television system, such as NTSC or
PAL, and outputs the signal. The display unit 108 is, e.g., a
viewfinder or a liquid crystal monitor and allows a user to monitor
an image currently being picked up, or a reproduced image, on the
basis of the output analog video signal from the D/A converter
106.
[0060] The CPU 112 controls the operation of the whole
recording/playback apparatus 100 via the data bus 109. The CPU 112
also controls parameters in the image pickup processing unit 102,
the camera signal processing unit 104, and the video signal
processing unit 105. The memory control unit 111 controls data
write to and read from the memory 110 in accordance with a control
signal from the CPU 112.
[0061] The arrangement of the disk unit 113 will be described below
with reference to FIG. 2.
[0062] FIG. 2 is a block diagram showing the arrangement of the
disk unit 113.
[0063] Referring to FIG. 2, this disk unit 113 includes a
magnetooptical disk 201, a magnetic head 202, a driver 203 of the
magnetic head, an optical pickup 214, and a preamplifier 205.
[0064] A disk motor 208 rotates the disk 201. A thread mechanism
210 moves the magnetic head 202 and the optical pickup 214 in the
radial direction of the disk.
[0065] In recording operation, this optical pickup 214 irradiates
the disk 201 with a laser beam emitted from a semiconductor laser
element (not shown) such as a laser diode. At the same time, an
encoder 204 performs error correction encoding and channel encoding
such as digital modulation for video data input via an interface
207. The driver 203 drives the magnetic head 202 with a driving
signal modulated on the basis of the data processed by the encoder
204. In accordance with this modulated driving signal, the magnetic
head 202 records the data by performing magnetic field modulation
on the disk 201.
[0066] In playback operation, the pickup 214 irradiates the disk
201 with a laser beam emitted from the semiconductor laser element
(not shown), detects the polarized light amount of reflected light
caused by the magnetic Kerr effect, and supplies the detected
amount to the preamplifier 205. The output signal from the
preamplifier 205 is subjected to demodulation and error correction
decoding by a decoder 206, and output to the video signal
processing unit 105 shown in FIG. 1 via the interface 207.
[0067] A DC motor 211 drives the thread mechanism 210. A servo
digital signal processor (DSP) 213 controls the rotational speed of
the disk and servo operations of the thread mechanism 210 by using
a motor driver 209 and a servo driver 212. More specifically, the
servo DSP 213 controls, e.g., rotational servo of the disk and
focusing servo, tracking servo, and seek servo of the pickup
system.
[0068] The bus I/F 207 exchanges recording/playback data with the
data bus 109 shown in FIG. 1. That is, the bus I/F 207 controls
input and output of data with respect to the encoder 204 during
recording and controls input and output of data with respect to the
decoder 206 during playback.
[0069] A file (TOC data) structure used in this embodiment will be
described below.
[0070] First, TOC data processing by the CPU 112 will be
explained.
[0071] In this embodiment, as shown in FIG. 9, an inner peripheral
portion 901 of a disk is used as a system management area, and TOC
data is recorded in this system management area 901. Video and
audio data are recorded in a video recording area 902.
[0072] The CPU 112 writes TOC data, which is read out from a disk
by the disk unit 113, into the memory 110 via the memory control
unit 111. In this state, the CPU 112 updates the TOC data stored in
the memory 110 in accordance with a recording or playback
operation. When recording is stopped by the recording trigger
switch or when the disk is to be ejected, the CPU 112 records the
TOC data in the system management area 901.
[0073] FIG. 3 shows the file directory structure of the
recording/playback apparatus 100. Referring to FIG. 3, a disk
medium 301 is defined as uppermost hierarchy O. In lower hierarchy
1, application attributions such as video 302, audio 303, a still
image 304, . . . , can be classified. In lower hierarchy 2 of any
file (in FIG. 3, the video 302) defined in hierarchy 1, video A
305, video B 306, video C 307, . . . , can be classified in
accordance with the dates of image pickup.
[0074] Subsequently, in lower hierarchy 3 of any file (in FIG. 3,
the video A 305) defined in hierarchy 2, scene 1 (308), scene 2
(309), scene 3 (310), . . . , partitioned by ON/OFF of the trigger
pointer can be classified. Furthermore, in lower hierarchy 4 of any
file (in FIG. 3, scene 1 (308)) defined in hierarchy 3, an image
pickup start pointer 311 (address information), an image pickup end
pointer 312 (address information), a link pointer 313 (address
information) which allows jump during editing and playback, . . . ,
of scene 1 can be classified.
[0075] Details of the TOC of the recording/playback apparatus 100
having this directory structure are shown in FIG. 4. FIG. 4 depicts
the structure of the TOC. This structure is roughly classified into
a TOC identification header portion containing all 0s or all 1s,
system information, and a management information table portion. For
each item, a start pointer 401, an attribution 402, an end pointer
403, and a link pointer 404 can be defined in units of a few
bytes.
[0076] As an example, playback control of a file in directory
hierarchy 3 shown in FIG. 3 will be explained with reference to
FIG. 4.
[0077] First, playback is started from the address, indicated by a
start pointer A of address 0001 in the management information table
portion, of the video recording area on a disk medium. After the
recorded data is continuously reproduced to an address indicated by
an end pointer B, the operation jumps to address AAAA indicated by
a link pointer. Subsequently, playback is started from the address,
indicated by a start pointer C, of the video recording area on the
disk medium. When the recorded data is completely reproduced to an
address indicated by an end pointer D, the playback is completed.
Link pointer 0000 in address AAAA is an index indicating the end of
playback. The playback of image data of each scene is controlled on
the basis of attribution information.
[0078] In this embodiment, as shown in FIG. 4, a U flag (Urgency
Flag) is set in the attribution information 402 of the system
information portion. This U flag is 1-bit digital information used
to check whether a TOC recorded in the system management area of a
disk is the latest one. The use of this U flag will be described in
detail later.
[0079] FIG. 5 is a view showing the arrangement of the electric
power unit 114 shown in FIG. 1. This electric power unit 114
includes a power reduction detector and monitors and detects a
decrease in electric power. Referring to FIG. 5, this electric
power unit 114 comprises a battery 501, DC-DC converters 502 and
503, resistors 504, 505, and 506 for dividing voltage, and
comparators 508 and 509.
[0080] Electric power from the battery 501 is converted into a
predetermined voltage by the DC-DC converter 502 and supplied to
each circuit of the recording/playback apparatus 100. The DC-DC
converter 503 and the subsequent elements detect power reduction.
That is, the output voltage from the DC-DC converter 503 is divided
to obtain a first threshold value (Th1) by the resistors 504 and
505 and a second threshold value (Th2) by the resistors 506 and
507. Note that Th1>Th2.
[0081] The comparator 508 compares the battery voltage 501 with Th1
and outputs a binary digital signal indicating the comparison
result. On the basis of the output from this comparator 508, the
CPU 112 instructs to display a power reduction warning if the
battery voltage is equal to or lower than Th1. The comparator 509
compares the battery voltage 501 with Th2 and outputs a binary
digital signal indicating the comparison result. On the basis of
the output from this comparator 509, the CPU 112 instructs to shut
down the power supply if the battery voltage is equal to or lower
than Th2.
[0082] A control operation by the CPU 112 in this embodiment will
be described below with reference to FIG. 6. FIG. 6 is a flow chart
for explaining recording and playback of image data and TOC data
performed by the CPU 112.
[0083] First, after power-on in step S601, the CPU 112 causes the
disk unit 113 to read out TOC data from the system management area
901 on the disk 201 and write the TOC data in the memory 111. In
step S602, the CPU 112 checks for the U flag of the TOC stored in
the memory 111. In this embodiment, if the U flag is "0", this
indicates that the TOC is normally recorded in the system
management area 901 of the disk 201 when the last image data is
recorded; if the U flag is "1", this indicates that the TOC is not
normally recorded in the system management area 901 of the disk 201
when the last image data is recorded.
[0084] If the U flag is "0" in step S602, the CPU 112 waits for a
processing instruction in steps S603 and S604. If the processing
instruction is other than the start of recording, the CPU 112
performs corresponding processing in step S605.
[0085] If the instruction is the start of recording, in step S606
the CPU 112 sets the U flag of the TOC data stored in the memory
111 to "1" which indicates that the TOC has not been updated, and
causes the disk unit 113 to record the TOC data having this U flag
"1" in the system management area 901 of the disk 201. After that,
the CPU 112 performs recording processing in step S607 and at the
same time always checks for the result of monitoring by the power
reduction detector of the electric power unit 114 in step S608.
[0086] If the CPU 112 detects in step S608 that the battery power
lowers and the voltage is below the predetermined voltage Th1, the
flow advances to step S612, and the CPU 112 stops recording the
image. In accordance with this recording stop position, in step
S613 the CPU 112 updates the contents of the TOC data stored in the
memory 111, so as to reflect the recording start pointer, end
pointer, and link pointer of the image data currently being
recorded, thereby urgently removing the TOC information.
[0087] In step S613, unlike normal recording processing of TOC
data, the TOC data is written following the trailing end of the
image data whose recording into the video information recording
area 902 is stopped, without moving the head mechanism of the disk
unit 113 to the system management area 901. After performing this
TOC data recording processing in step S613, the CPU 112 waits for
the next instruction.
[0088] On the other hand, if the battery power is not low in step
S608 and a recording stop instruction is detected in step S609, in
step S610 the CPU 112 updates the contents of the TOC data stored
in the memory 111, so as to reflect the start pointer, end pointer,
and link pointer of the latest recorded image data, and sets the U
flag to "0". In step S611, the CPU 112 moves the head mechanism to
the system management area 901 and writes the TOC information
having the updated contents and the U flag "0" in this system
management area 901.
[0089] If in step S602 the U flag is set to "1" indicating that the
TOC does not show the latest contents, the flow advances to step
S614.
[0090] In this case, the TOC recorded in the system management area
901 has not been updated to the latest information. Therefore, the
CPU 112 sequentially searches the video recording area 902 of the
disk 201 from a position indicated by the final end pointer of the
latest TOC information recorded in the system management area 901,
and reads out the latest TOC information recorded in the video
information recording area 902 as described previously. In step
S615, on the basis of the readout latest TOC information, the CPU
112 updates the contents of the TOC information stored in the
memory 111 and sets the U flag to "0". In step S616, the CPU 112
records this TOC information in the system management area 901
which is the original recording area of TOC information.
[0091] The CPU 112 continues the above operation until power-off or
until the battery voltage becomes lower than Th2 and then the
comparator 509 shown in FIG. 5 outputs a signal indicating a
power-supply voltage drop.
[0092] In this embodiment as described above, even when the battery
voltage lowers during recording, TOC information reflecting the
latest recorded contents can be reliably recorded.
[0093] The second embodiment will be described next. A
recording/playback apparatus of this embodiment has the same
configuration as the image pickup recording/playback apparatus
explained with reference to FIGS. 1, 2, and 5 in the first
embodiment, so a detailed description thereof will be omitted.
[0094] In the second embodiment, a TOC is constructed as shown in
FIG. 7. One-bit remove information indicating that this TOC
information is not normally recorded and its contents do not
reflect the latest recorded contents can be described in the MSBs
of attribution data 402' in a management information table
portion.
[0095] Processing by a CPU 112 in this embodiment will be described
below with reference to a flow chart in FIG. 8.
[0096] First, after power-on in step S801, the CPU 112 causes a
disk unit 113 to read out TOC data from a system management area
901 on a disk 201 and write the TOC data in a memory 111. In step
S802, the CPU 112 checks for all MSBs in the attributions 402' of
the TOC stored in the memory 111. In this embodiment, if the MSB of
the attribution 402' is "0", this indicates that the TOC is
normally recorded in the system management area 901 of the disk 201
when the last image data is recorded; if the MSB is "1", this
indicates that the TOC is not normally recorded in the system
management area 901 of the disk 201 when the last image data is
recorded and that the contents of this TOC do not correspond to the
latest recorded contents.
[0097] If the M8B of the attribution 402' is "0" in step S802, the
CPU 112 waits for a processing instruction in steps S803 and S804.
If the processing instruction is other than the start of recording,
the CPU 112 performs corresponding processing in step S805.
[0098] If the instruction is the start of recording, in step S806
the CPU 112 sets the MSB of the attribution 402' of the TOC data
stored in the memory 111 to "1" which indicates that the TOC has
not been updated, and causes the disk unit 113 to record the TOC
data having this MSB "1" of the attribution 402' in the system
management area 901 of the disk 201. After that, the CPU 112
performs recording processing in step S807 and at the same time
always checks for the result of monitoring by a power reduction
detector of an electric power unit 114 in step S808.
[0099] If in step S808 the CPU 112 detects the battery supply
limit, i.e., detects that the battery voltage is below a
predetermined voltage Th1, the flow advances to step S812, and the
CPU 112 stops recording the image. In accordance with this
recording stop position, in step S813 the CPU 112 updates the
contents of the TOC data stored in the memory 111, so as to reflect
the recording start pointer, end pointer, and link pointer of the
image data currently being recorded, thereby urgently removing the
TOC information.
[0100] In step S813, unlike normal recording processing of TOC
data, the TOC data is written following the trailing end of the
image data whose recording into a video information recording area
902 is stopped, without moving a head mechanism of the disk unit
113 to the system management area 901. After performing this TOC
data recording processing in step S813, the CPU 112 waits for the
next instruction.
[0101] On the other hand, if the battery power is not low in step
S808 and a recording stop instruction is detected in step S809, in
step S810 the CPU 112 updates the contents of the TOC data stored
in the memory 111, so as to reflect the start pointer, end pointer,
and link pointer of the latest recorded image data, and sets the
MSB of the attribution 402' to "0". In step S811, the CPU 112 moves
the head mechanism to the system management area 901 and writes the
updated TOC information in this system management area 901.
[0102] If in step S802 the MSB of the attribution 402' is set to
"1" indicating that the TOC does not show the latest contents, the
flow advances to step S814.
[0103] In this case, the TOC recorded in the system management area
901 has not been updated to the latest information. Therefore, the
CPU 112 sequentially searches the video recording area 902 of the
disk 201 from a position indicated by the final end pointer of the
newest TOC information recorded in the system management area 901,
and reads out the latest TOC information recorded in the video
information recording area 902 as described above. In step S815, on
the basis of the readout latest TOC information, the CPU 112
updates the contents of the TOC information stored in the memory
111 and sets the MSB of the attribution 402' to "0". In step S816,
the CPU 112 records this TOC information in the system management
area 901 which is the original recording area of TOC
information.
[0104] The CPU 112 continues the above operation until power-off or
until the battery voltage becomes lower than Th2 and then a
comparator 509 shown in FIG. 5 outputs a signal indicating a
power-supply voltage drop.
[0105] In this embodiment as described above, even when the battery
voltage lowers during recording, TOC information reflecting the
latest recorded contents can be reliably recorded and
reproduced.
[0106] In the first and second embodiments, the present invention
is applied to the recording/playback apparatus 100. However, the
present invention is similarly applicable to any apparatus which
separately records main information and its management information
in separated areas on a recording medium.
[0107] The third embodiment of the present invention will be
described below with reference the accompanying drawings.
[0108] FIG. 10 is a block diagram showing a recording apparatus
1000 according to this embodiment of the present invention.
[0109] This recording apparatus 1000 comprises an image pickup unit
1001, a picture rearrangement circuit 1002, a switch 1003, a
subtractor 1004, a DCT (Discrete Cosine Transform) circuit 1005, a
quantization circuit 1006, a variable-length encoding circuit 1007,
an inverse quantization circuit 1008, an IDCT (Inverse Discrete
Cosine Transform) circuit 1009, an adder 1010, a motion
compensation prediction circuit 1011, a switch 1012, a buffer 1013,
a rate control circuit 1014, a recording processing circuit 1015, a
magnetooptical disk 1016, a picture change detection circuit 1017,
a TOC memory 1018 for storing TOC information, a TOC control
circuit 1019, and an operation unit 1020 which includes, e.g., a
power switch and a recording trigger switch.
[0110] The operation will be described next.
[0111] A digital image signal obtained by the image pickup unit
1001 is input in units of frames to the picture rearrangement
circuit 1002. This picture rearrangement circuit 1002 has a memory
capable of storing a digital image signal having a plurality of
frames. By using this memory, the picture rearrangement circuit
1002 rearranges frames of the input image signal and outputs the
signal.
[0112] The operation of the picture rearrangement circuit 1002 will
be explained below with reference to FIG. 11.
[0113] Referring to FIG. 11, an image signal input in units of
frames in the order of a first frame, second frame, third frame, .
. . , is output by rearranging these frames in the order of the
third frame, first frame, second frame, . . . .
[0114] The picture rearrangement process shown in FIG. 11 is
necessary to perform intra-encoding and inter-encoding for an image
signal as shown in FIG. 12.
[0115] The intra-encoding is a method of encoding using only data
in one frame and generates an I picture shown in FIG. 12. The
inter-encoding is a method of encoding also using interframe
prediction and generates P and B pictures shown in FIG. 12.
[0116] The intra-encoding and inter-encoding will be described
next.
[0117] To perform the intra-encoding, the switch 1003 is closed to
a terminal A. The output image data from the picture rearrangement
circuit 1002 is input to the DCT circuit 1005 via the switch 1003
and orthogonally transformed. The quantization circuit 1006
quantizes the orthogonally transformed image data in accordance
with a quantization coefficient determined by the rate control
circuit 1014. The quantized image data is input to the inverse
quantization circuit 1008 and the variable-length encoding circuit
1007.
[0118] The output image data from the picture rearrangement circuit
1002 is also input to the motion compensation prediction circuit
1011 and the picture change detection circuit 1017.
[0119] The quantized data is inversely quantized by the inverse
quantization circuit 1008 and subjected to IDCT by the IDCT circuit
1009. The switch 1012 is turned off to supply the image data
subjected to IDCT to the motion compensation prediction circuit
1011. The motion compensation prediction circuit 1011 generates and
outputs a predictive image for the subsequent inter-encoding.
[0120] The quantized data is also input to the variable-length
encoding circuit 1007 where the data is variable-length-encoded.
The encoded data is input to the buffer 1013. When reaching a
certain predetermined data amount, the image data in the buffer
1013 is output to the recording processing circuit 1015. This
recording processing circuit 1015 has an arrangement as shown in
FIG. 2 and records the data on the magnetooptical disk 1016. The
recording processing circuit 1015 can record data at a higher data
rate than the rate of image data input to the buffer 1013. In
practice, the recording processing circuit 1015 intermittently
reads out data in units of predetermined amounts of data from the
buffer 1013 and records the readout data.
[0121] To perform the inter-encoding, the switch 1003 is closed to
a terminal B. The subtractor 1004 is used to lower the redundancy
in the time axis. This subtractor 1004 outputs the difference
between the output image data from the picture rearrangement
circuit 1002 and the predictive image data from the motion
compensation prediction circuit 1011 to the terminal B of the
switch 1003.
[0122] The output data from the subtractor 1004 is input to the DCT
circuit 1005 via the switch 1003 and orthogonally transformed. The
quantization circuit 1006 quantizes the orthogonally transformed
image data in accordance with a quantization coefficient determined
by the rate control circuit 1014. The quantized image data is input
to the inverse quantization circuit 1008 and the variable-length
encoding circuit 1007.
[0123] The output image data from the picture rearrangement circuit
1002 is also input to the motion compensation prediction circuit
1011 and the picture change detection circuit 1017.
[0124] The quantized data is inversely quantized by the inverse
quantization circuit 1008 and subjected to IDCT by the IDCT circuit
1009. In this inter-encoding, the switch 114 is turned on to allow
the adder 1010 to add the image data from the IDCT circuit 1009 and
the predictive image data from the motion compensation prediction
circuit 1011, thereby obtaining decoded image data. This decoded
image data is input to the motion compensation prediction circuit
1011 for the subsequent image encoding. The motion compensation
prediction circuit 1011 outputs predictive image data and a motion
vector. This motion vector is input to the variable-length encoding
circuit 1007.
[0125] The quantized data is input to the variable-length encoding
circuit 1007 where the data is variable-length-encoded. The encoded
data is input to the buffer 1013. When reaching a certain
predetermined data amount, the image data in the buffer 1013 is
output to the recording processing circuit 1015. The recording
processing circuit 1015 records the image data on the disk
1016.
[0126] Recording of a TOC as index information in this embodiment
will be described below.
[0127] Also in this embodiment, TOC information is recorded in a
system management area 901 on a disk shown in FIG. 9.
[0128] When the power supply is turned on by the operation unit
1020, the TOC control circuit 1019 stores TOC information, read out
from the system management area on the disk 1016 by the recording
processing circuit 1015, in the TOC memory 1018. In accordance with
recording processing, the TOC control circuit 1019 updates the
contents of the TOC information stored in the TOC memory 1018. When
the stop of recording is designated by the operation unit 1020, the
TOC control circuit 1019 reads out the latest TOC information
stored in the TOC memory 1018. The recording processing circuit
1015 records the readout TOC information in the system management
area of the disk 1016.
[0129] Furthermore, the TOC control circuit 1019 records the TOC
information stored in the TOC memory 1018 into the disk 1016 in
accordance with an output from the picture change detection circuit
1017.
[0130] This picture change detection circuit 1017 reads out image
data of a plurality of frames stored in the picture rearrangement
circuit 1002 and calculates a difference A
A=.intg.|Frame1(Y)-Frame2(Y)| (1)
in luminance information between frames. If this difference A is
larger than a certain threshold value TH, i.e., if A>TH, the
picture change detection circuit 1017 outputs a control signal
indicating a picture change to the TOC control circuit 1019.
[0131] When detecting this control signal, the TOC control circuit
1019 controls the TOC memory 1018 to record TOC information which
reflects the contents of recording up to the point, in the system
management area of the disk 1016 by the recording processing
circuit 1015, by using a period during which no image data is
recorded.
[0132] FIGS. 13 and 14 are views for explaining TOC recording
timings.
[0133] Symbols * in FIG. 13 indicate timings at which the picture
change detection circuit 1017 detects a large picture change.
[0134] Referring to FIG. 13, in scene 1, TOC information is
recorded in the system management area at the timings of detection
of picture change 1301, temporary stop 1302, and stop of recording
1303.
[0135] As described earlier, image data is output to the recording
processing circuit 1015 via the buffer 1013. Also, the recording
processing circuit 1015 can record data on the disk 1016 at a
higher rate than the data rate of image data input to the buffer
1013.
[0136] That is, the recording processing circuit 1015 performs
intermittent recording on the disk 1016. As shown in FIG. 14,
therefore, non-record periods are produced during recording of
image data. FIG. 14 shows recording periods 1401 and data
non-record periods 1402. Accordingly, when a picture change is
detected at timing 1401a, TOC information can be recorded, even
during image data recording, by moving the head to the system
management area in a data non-record period 1402a.
[0137] Also, in scene 1 of FIG. 13, recording is normally stopped
at timing 1303. Hence, TOC information reflecting data recorded up
to this stop of recording 1303 is recorded in the disk 1016. So,
all recorded data up to 1303 can be correctly reproduced.
[0138] In scene 2, TOC information is recorded in the system
management area at picture change detection timings 1304 and 1305.
In this example, the power supply is shut down at timing 1306
before recording stop operation, so recording is not normally
stopped. However, TOC information is recorded on the disk 1016 at
the timing 1305 at which a picture change is detected. The TOC
information recorded at this timing 1305 reflects the contents of
image data recorded up to 1305. In playback, therefore, data from
the start of recording of scene 2 to the timing 1305 at which a
picture change is lastly detected can be correctly reproduced.
[0139] In this embodiment, a picture change is detected by the
difference between frames. However, a picture change can also be
detected by another method.
[0140] For example, as shown in FIGS. 15A and 15B, a histogram of
the directions of motion vectors calculated by the motion
compensation prediction circuit 113 is obtained in one frame. If
the correlation between the motion vectors in one frame is low, a
picture change is detected.
[0141] Referring to FIG. 15A, motion vectors having angles of 0 to
90 0 is largest in number, so changes between pictures are
obviously small. Referring to FIG. 15B, the angles of motion
vectors evenly distribute in all directions, so changes between
pictures are obviously large.
[0142] A recording apparatus according to the fourth embodiment of
the present invention will be described below.
[0143] FIG. 16 is a block diagram showing the configuration of a
recording apparatus 1000 of this embodiment. The same reference
numerals as in the configuration shown in FIG. 10 denote the same
parts, and a detailed description thereof will be omitted.
[0144] This apparatus shown in FIG. 16 includes an audio input unit
1021, an audio change detection circuit 1022, an audio encoding
circuit 1023, a buffer 1024, and a multiplexer 1025.
[0145] Encoding of image data in FIG. 16 is the same as the
apparatus shown in FIG. 10, so a detailed description thereof will
be omitted. Encoded image data stored in the buffer 1013 is
multiplexed with audio data by the multiplexer 1025 and output to a
recording processing circuit 1015.
[0146] The audio input unit 1021 includes an audio input device
such as a microphone and outputs a digital audio signal pertaining
to an object to the audio change detection circuit 1022 and the
audio encoding circuit 1023. The audio encoding circuit 1023
encodes this audio data by using a known coding scheme and outputs
the encoded image data to the buffer 1024. The multiplexer 1025
multiplexes the image data stored in the buffer 1013 and the audio
data stored in the buffer 1024 such that pictures and audio are
synchronized. The multiplexed data is output to the recording
processing circuit 1015.
[0147] Recording of a TOC as an important point of the present
invention will be described next.
[0148] Also in this embodiment, TOC information is recorded in a
system management area 901 on a disk shown in FIG. 9.
[0149] When the power supply is turned on by an operation unit
1020, a TOC control circuit 1019 stores TOC information read out
from the system management area on a disk 1016 by the recording
processing circuit 1015, in a TOC memory 1018. In accordance with
recording processing, the TOC control circuit 1019 updates the
contents of the TOC information stored in the TOC memory 1018. When
the stop of recording is designated by the operation unit 1020, the
TOC control circuit 1019 reads out the newest TOC information
stored in the TOC memory 1018. The recording processing circuit
1015 records the readout TOC information in the system management
area of the disk 1016.
[0150] In this embodiment, the TOC control circuit 1019 further
records the TOC information stored in the TOC memory 1018 into the
disk 1016 in accordance with an output from the audio change
detection circuit 1022.
[0151] This audio change detection circuit 1022 has a comparator
and, as shown in FIG. 17, outputs a high-level signal to the TOC
control circuit 1019 when a period during which the level of an
input audio signal is lower than a predetermined threshold Ath
continues for a predetermined time Tth or more. When the audio
change detection circuit 1022 outputs this high-level control
signal, the TOC control circuit 1019 controls the TOC memory 1018
to record TOC information which reflects the contents of recording
up to the point, in the system management area of the disk 1016 by
the recording processing circuit 1015, by using a period during
which neither image data nor audio data are recorded.
[0152] FIG. 18 is a view for explaining TOC recording timings.
[0153] Symbols * in FIG. 18 indicate timings at which the audio
change detection circuit 1022 outputs a control signal indicating
that a period in which the input audio level is lower than the
threshold value is detected. In scene 1, TOC information is
recorded in the system management area 901 of the disk 1016 at the
timings of audio change detection 1801, temporary stop 1802, and
stop of recording 1803.
[0154] Also in this embodiment, image data is output to the
recording processing circuit 1015 via a buffer 1013. Also, the
recording processing circuit 1015 can record data on the disk 1016
at a higher rate than the data rate of image data input to the
buffer 1013.
[0155] That is, the recording processing circuit 1015 performs
intermittent recording on the disk 1016. As shown in FIG. 14,
therefore, non-record periods are produced during recording of
image data. FIG. 14 shows recording periods 1401 and data
non-record periods 1402. Accordingly, when a picture change is
detected at timing 1401a, TOC information can be recorded, even
during image data recording, by moving the head to the system
management area 901 in a data non-record period 1402a.
[0156] Also, in scene 1 of FIG. 18, recording is normally stopped
at timing 1803. Hence, TOC information reflecting data recorded up
to this stop of recording 1803 is recorded in the disk 1016. So,
all recorded data up to 1803 can be correctly reproduced.
[0157] In scene 2, TOC information can be recorded in the system
management area on the disk 1016 at audio change detection timings
1804 and 1805. In this example, the power supply is shut down at
timing 1806 before recording stop operation, so recording is not
normally stopped.
[0158] In this embodiment, however, TOC information reflecting the
contents of recording up to the point is recorded on the disk 1016
at the timing 1805 at which an audio change is detected. Therefore,
data from the start of recording of scene 2 to the timing 1805 at
which an audio change is lastly detected can be correctly
reproduced.
[0159] The fifth embodiment of the present invention will be
described below with reference to the accompanying drawings.
[0160] FIG. 19 is a block diagram showing the configuration of a
recording apparatus 1000 according to this embodiment. The same
reference numerals as in the configurations shown in FIGS. 10 and
16 denote the same parts, and a detailed description thereof will
be omitted.
[0161] The recording apparatus of this embodiment further comprises
a system control circuit 1026 for controlling the overall operation
of the apparatus 1000, a still image encoding circuit 1027, a
buffer 1028 for still image signals, and a buffer 1029 for TOC
information.
[0162] Referring to FIG. 19, the system control circuit 1026
controls the operation of each unit of the apparatus. That is, in
accordance with instructions from an operation unit 1020, the
system control circuit 1026 controls a picture rearrangement
circuit 1002, switches 1003 and 1012, and the still image encoding
circuit 1027.
[0163] First, the operation of normal motion image recording will
be described below.
[0164] When the start of motion image recording is designated by
the operation unit 1020, the system control circuit 1026 controls a
picture rearrangement circuit 1022 to rearrange frames of an image
signal from an image pickup unit 1001 as shown in FIG. 11, and
outputs the signal to a switch 1003, a subtractor 1004 and a motion
compensation prediction circuit 1011. After that, this motion image
signal is encoded as described earlier by, e.g., a DCT circuit
1005, a quantization circuit 1006, a variable-length encoding
circuit 1007, an inverse quantization circuit 1008, an IDCT circuit
1009, an adder 1010, and the motion compensation prediction circuit
1011. The encoded signal is output to a buffer 1013.
[0165] Also, an input audio signal from an audio input unit 1021 is
encoded by an audio encoding circuit 1023 and output to a buffer
1024.
[0166] The operation of still image recording will be described
next.
[0167] The recording apparatus of this embodiment has a still image
recording mode. When still image recording is designated by the
operation unit 1020 during recording of a motion image signal, a
still image signal can be recorded on a disk 1016 independently of
the motion image signal.
[0168] When the operation unit 1020 designates still image
recording, the system control circuit 1026 outputs a control signal
to the picture rearrangement circuit 1022 to extract image data of
a frame, at the timing corresponding to the still image recording
instruction, from an image signal having a plurality of frames
output from the image pickup unit 1001. The extracted image signal
is output to the still image encoding circuit 1027.
[0169] In accordance with a control signal from the system control
circuit 1026, the still image encoding circuit 1027 receives the
image data of one frame output from the picture rearrangement
circuit 1002, encodes the data on the basis of a JPEG standard for
still image encoding, and outputs the encoded still image data to
the buffer 1028. The encoding scheme of this still image encoding
circuit 107 is, of course, not limited to JPEG encoding. For
example, base band encoding can also be performed. The still image
encoding circuit 1027 performs real-time processing at a rate of,
e.g., 4 Mbits/sec.
[0170] Under the control of the system control circuit 1026, a
multiplexer 1025 time-divisionally multiplexes the motion image
signal and audio signal stored in the buffer 1024, the still image
signal stored in the buffer 1028, and TOC information stored in the
buffer 1029 (as will be described later), and outputs the
multiplexed data to a recording processing unit 1015. The recording
processing unit 1015 records this multiplexed data in the
magnetooptical disk 1016.
[0171] FIG. 20 is a view showing recording areas of TOC data,
motion image' audio data, and still image data on the disk 1016
according to this embodiment.
[0172] Referring to FIG. 20, TOC data is recorded in a TOC
recording area 901 in the innermost peripheral portion as in FIG.
9. In this embodiment, a video recording area is divided into a
motion image recording area 902A and a still image recording area
902B. That is, still image data is recorded in the still image
recording area 902B outside the TOC recording area 901. Motion
image audio data is recorded in the motion image audio recording
area 902A outside the still image recording area 902B.
[0173] The still image recording area 902B and the motion image
audio recording area 902A are segmented into sectors toward the
outer periphery, and these sectors are assigned sector numbers in
order. Each sector is referred to by the start address, end"
address, and the like in TOC data.
[0174] As shown in FIG. 21, the recording processing circuit 1015
records variable-length motion image data in units of GOP and
fixed-length audio data in a time series manner in the motion image
recording area 902A on the disk 1016. In encoding of MPEG2, a
plurality of frames between two I pictures are called 1GOP (Group
Of Pictures) and used as a unit of encoding. Usually, 1GOP is
composed of 15 frames.
[0175] When still image data is stored in the buffer 1028 in
response to a still image recording instruction, the system control
circuit 1026 controls the multiplexer 1025 to read out this still
image data stored in the buffer 1028 by using a period during which
recording of motion image data and audio data on the disk 1016 is
stopped, i.e., a period 1401 shown in FIG. 14. The readout still
image data is recorded in the still image recording area 902B
different from the motion image recording area 902A on the disk
1016.
[0176] TOC data in this embodiment will be described below.
[0177] FIG. 22 is a view showing the contents of TOC data according
to this embodiment.
[0178] The TOC of this embodiment has a scene table 2201 and a
contents table 2202. The scene table 2201 shows the order of scenes
and the correspondence between each scene and a row in the contents
table 2202. In playback, scenes are usually reproduced in the order
in this scene table 2201.
[0179] Also, the scene table 2201 can manage 4,095 scenes, and each
scene has a 12-bit pointer which indicates a specific row in the
contents table 2202. This scene table 2201 is used in order from 1,
and a pointer having no corresponding scene has "0" which indicates
the end.
[0180] The contents table 2202 has 4,095 rows, and each row has a
start address 2203, an end address 2204, a link pointer 2205, and
an attribution 2206. The start address 2203 and the end address
2204 are composed of 20 bits each and have the start and end
addresses, respectively, of a corresponding scene.
[0181] The link pointer 2205 has a pointer indicating the row of
the continuation of a scene, when a certain scene is connected to
another scene to form one scene or when one scene is dispersedly
recorded in discontinuous areas owing to the locations of empty
areas. As indicated by an arrow in FIG. 22, when the continuation
of a scene shown in row 1 of the contents table 2202 is shown in
row 3, "3" is stored in the link pointer 2205 of row 1 to hold the
continuity of the scene.
[0182] The attribution 2206 stores data indicating an attribution
such as motion image, still image, or copy inhibition.
[0183] Data to be processed is, of course, not restricted to motion
image-audio data and still image data but can be script data and
the like. The type of data can be described in the attribution 2206
of the TOC data.
[0184] A summary of updating of TOC data as management information
in the present invention will be explained below. Details will be
described later.
[0185] When the power supply is turned on, only TOC data is
reproduced from the TOC recording area 901 on a recording medium
and stored in the TOC memory 1018. The system control circuit 1026
can instantly know which data is stored in which area on the disk
1016 at present by referring to the TOC data loaded into the TOC
memory 1018. To record a motion image and a still image, therefore,
the system control circuit 1026 so controls as to record new data
by designating an empty area on the basis of the TOC.
[0186] In this embodiment, whenever the operation unit 1020
designates still image recording, the system control circuit 1026
updates the TOC data stored in the TOC memory 1018 to have contents
recorded up to that point, i.e., to have contents reflecting all
pieces of information concerning motion image data recorded up to
that point and still image data to be recorded henceforth.
[0187] The system control circuit 1026 outputs the TOC data having
the updated contents to the buffer 1029 and records the still image
data, stored in the buffer 1028, into the still image recording
area 902B on the disk at the aforementioned timing. Subsequently,
the system control circuit 1026 reads out the TOC data stored in
the buffer 1029 and records the readout TOC data in the system
management area 901 on the disk 1016. Also in this embodiment,
whenever the operation unit 1020 designates the start and end of
normal motion image recording, the system control circuit 1026
updates the contents of the TOC data, supplies the updated TOC data
from the TOC memory 1018 to the buffer 1029, and records the TOC
data in the system management area 901 on the disk 1016.
[0188] Still image recording can be designated even while no motion
image is being recorded. Also in this case, TOC data is updated and
recorded on the disk 1016.
[0189] In this embodiment as described above, when recording of a
still image is instructed while a motion image is being recorded,
TOC data reflecting recorded contents is recorded on a disk at that
time.
[0190] During image pickup of one scene, therefore, even when
abnormality such as a decrease in remaining battery amount occurs
and recording of a motion image is not normally terminated, if
still image recording is designated at least once while a motion
image is being picked up, TOC data reflecting recorded contents up
to that point the still image data is recorded can be recorded on a
disk.
[0191] Accordingly, the motion image data, audio data, and still
image data recorded up to that point can be correctly
reproduced.
[0192] The present invention can be applied to a system constituted
by a plurality of devices or an apparatus comprising a single
device.
[0193] Further, the objects of the present invention can also be
achieved by supplying a storage medium (or a recording medium)
recording program codes of software for realizing the functions of
the abovementioned embodiments to a system or an apparatus, and
allowing a computer (e.g., a CPU or MPU) of the system or the
apparatus to read out and execute the program codes stored in the
storage medium. In this case, the program codes themselves read out
from the storage medium realize the functions of the above
embodiments, and the storage medium storing the program codes
constitutes the invention. Furthermore, besides the functions of
the above embodiments are realized by executing readout program
codes by a computer, the present invention includes a case where an
OS (Operating System) or the like running on the computer executes
a part or the whole of actual processing on the basis of
instructions by the program codes, and the functions of the
embodiments are achieved by the processing.
[0194] The present invention also includes a case where, after the
program codes read out from the storage medium are written in a
memory of a function extension board inserted into a computer or of
a function extension unit connected to the computer, a CPU or the
like of the function extension board or function extension unit
performs a part or the whole of actual processing on the basis of
instructions by the program codes, and the functions of the above
embodiments are accomplished by the processing.
[0195] Many widely different embodiments of the present invention
may be constructed without departing from the 5 spirit and scope of
the present invention. It should be understood that the present
invention is not limited to the specific embodiments described in
the specification, except as defined in the appended claims.
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