JPH11219525A - Disk shaped recording medium, recorder and reproducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To more reinforce a data protective effect at the time of a data recording by recording data on tracks different each other every recording data unit after a recording density is enhanced by forming tracks of both sides sharing a physical wobble in which address information are encoded in helical form. SOLUTION: Tracks Tr.A and B of lands Ld sharing a wobbled groove WG in which physical addresses between non-wobbled grooves NWG are encoded are formed in helical form on a disk. Respective recordings and reprodutions are performed by allowing a main beam spot SP and side beam spots SPs1 and s2 to respectively trace the track Tr.A, grooves NWG and WG. The track picth of tracks Tr.A and B is made to be 0.95 μm and a certain recording data unit and a recording data unit being on a sequence positioning next to the recording unit are recorded on tracks different each other. Thus, a recording density becomes high and a data recording having high reliability is easily performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk-shaped recording medium on which, for example, compressed image data and audio data are recorded, a recording apparatus for performing recording and reproduction corresponding to such a disk-shaped recording medium, and a reproduction apparatus. It concerns the device.

[0002]

2. Description of the Related Art In recent years, for example, in various disk-shaped recording media (hereinafter, simply referred to as disks), high-density recording has been promoted by considering a logical or physical recording method. For moving image data, for example, MPEG (Moving Picture Experts Gr.)
oup) 1, a compression method such as the MPEG2 format has been proposed. By using such a high-density recording of the disk and the compression processing of the moving image data, the recording time of the moving image on the disk-shaped recording medium can be considerably extended.

[0003]

However, in the case of a disk, for example, when a disturbance such as an impact is given while recording data as a certain file, for example, the recording position with respect to the disk is physically moved. There is a possibility that the data of the previously recorded file may be destroyed. For this reason, even if a recording error as described above occurs, it is necessary to consider a data recording method suitable for a format corresponding to the disc so that data of a file or the like recorded in the past is not destroyed as much as possible. There is.

In an image compression format such as the MPEG2 format, as is well known, a so-called encoding bit rate (data rate) is a constant rate (CBR; Constant Bit Rate) and a variable rate (VB).
R; Variable Bit Rate) are supported. For example, considering high-density recording,
It would be advantageous to employ VBR. However, MPE
When VBR is adopted as G2, for example, fast forward /
The data rate (corresponding to the data capacity) of a data unit called a GOP (Group Of Pincture), which is a data unit for special playback such as fast rewinding and various kinds of editing, is also variable. When the data rate of the GOP is made variable in this way, it is said that it is difficult to actually realize various special reproductions and editing processes using the data units of the GOP. That is, if various types of special reproduction and editing processing are performed in GOP units with variable data rates, many types of definition contents corresponding to the variable data rates are used as management information for recording and reproduction required for each GOP. It is necessary to set, but in this case, the data capacity of the management information becomes enormous. Therefore, if various special reproduction and editing processes are actually performed using such a large amount of management information, the overhead will slow down the system operation, store the management information, and work on the image data. A very large memory capacity to be used as an area is required.

[0005]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention is intended to record data with the highest possible reliability, for example, while increasing the recording density of a disk-shaped recording medium. The purpose is to: Furthermore, as data recorded on such a disk-shaped recording medium, for example, it is considered that moving image data with a variable data rate is recorded. In such a case, data processing for a reproducing operation and editing processing is also performed. It is intended to be easily performed.

Therefore, in the disk-shaped recording medium of the present invention, two tracks sharing a physical wobble in which address information is encoded are spirally formed as tracks on which data is recorded. When the data to be recorded in the recording data unit is based on a sequence of recording data units defined by a predetermined format, a certain recording data unit and a recording data unit positioned next to the certain recording data unit in the sequence Are recorded on different tracks. As a result, first, two tracks sharing physical wobbles as address information are formed in a spiral shape, thereby reducing the total occupied area of wobbles on the disk and narrowing the track pitch to thereby increase the density. After recording is performed, data to be recorded on the disc by a series of recording operations can be recorded in a physically dense state on a recording area in a radial direction on the disc.

Further, as a disk-shaped recording medium, data in a sequence of data units to be managed, which are data units having a fixed length, and management information for managing a recording or reproducing operation for each data unit to be managed are recorded. At the same time, in the managed data unit, at least
An image data storage area in which one or more variable-length compressed data units forming compressed moving image data compressed at a variable rate are stored is set. Thus, for example, even if the variable-length compressed data unit is originally the minimum editing unit in the compressed image data with a variable data rate, by storing this in the fixed-length managed data unit, the variable-length compressed data It is possible to manage the unit as a fixed-length data unit.

A variable-length compressed data unit obtaining means for obtaining a variable-length compressed data unit forming compressed moving image data compressed at a variable rate, and a fixed-length data unit for recording / reproduction management. A managed data unit generating means configured to generate a managed data unit storing at least one or more of the variable length compressed data units; and a recording or reproducing operation for each managed data unit on a disk-shaped recording medium. The recording device is configured to include recording of management information for performing management and recording control means capable of recording data in a sequence of data units to be managed. Accordingly, a disk-shaped recording medium on which image data that can be managed is recorded by regarding the variable-length compressed data unit as an editing unit in the compressed image data with a variable data rate as a fixed-length data unit based on a management target data unit Can be obtained.

In addition, data in a sequence of data units to be managed, which are fixed length data units, and management information for managing a recording or reproducing operation for each of the data units to be managed are recorded. In the target data unit, reproduction can be performed corresponding to a disk-shaped recording medium storing at least one variable-length compressed data unit forming compressed moving image data that has been subjected to compression processing at a variable rate. As a device, based on the management information described above, it reads out the data to be managed from the disk-shaped recording medium and executes playback control for playing back and outputting data stored in the read-out data unit to be managed. And a reproduction control means. That is, for example, in the case of performing image reproduction based on the variable-length compressed data unit, it is possible to perform reproduction with easy reproduction management by handling data in the data to be managed based on the management information. It is what becomes.

Further, the data unit is a fixed length data unit,
At least, a sequence of management target data units in which one or more variable length compressed data units forming compressed moving image data compressed at a variable rate are stored, and an auxiliary to be reproduced and output together with the variable length compressed data units Audio data is recorded, and the auxiliary audio data is managed by the reproduction management information so that the data position to be reproduced corresponding to each variable length compressed data unit is specified. The following is a configuration of a reproducing apparatus capable of performing reproduction in accordance with the following. That is, data is read out from the disk-shaped recording medium in units of management target data, and at least reproduction and output of an image in a required display mode are performed based on the variable length compressed data units extracted from the read management target data units. And a data position of auxiliary audio data to be reproduced and output for each variable-length compressed data unit reproduced and output by the image reproduction control means, based on the reproduction management information. At a predetermined timing from the data position specified by the data position specifying means so that the auxiliary sound is reproduced and output in synchronization with the variable length compressed data unit reproduced and output by the image reproduction control means. A reproduction apparatus comprising auxiliary sound reproduction control means capable of reproducing auxiliary sound data; It is. This allows, for example,
As a playback operation corresponding to a disk-shaped recording medium on which auxiliary audio data is recorded independently of a sequence (for example, moving image data) of the data to be managed, synchronization is performed with a playback image obtained from the data to be managed. In this way, it is possible to reproduce and output appropriate auxiliary audio data.

[0011]

Embodiments of the present invention will be described below. The recording device and the reproducing device of this example are mounted on a portable video camera in which a camera device and a recording and reproducing device capable of recording and reproducing images (still images or moving images) and audio are integrated. An example is given below. The disc-shaped recording medium of this embodiment is a so-called mini-disc, which is known as a type of magneto-optical disc. , And a configuration for recording and reproducing data. The description will be made in the following order. 1. Disk format 2. 2. External configuration of video camera 3. Internal configuration of video camera 4. Configuration of media drive section 5. Example of disk structure corresponding to this embodiment Recording of packet 6-1. Packet structure 6-2. Example of Packet Recording Method on Disk 6-3. Processing operation 7. Reproduction of packet 7-1. Example of packet management form 7-2. 7. Editing process example in packet unit 8. Dubbed file recording / playback Cue / review playback (during dubbing playback)

1. Disc Format The recording / reproducing device section mounted on the video camera of this example is assumed to be compatible with a format called MD data, which records / reproduces data in correspondence with a mini disc (magneto-optical disc). . As this MD data format, two types of formats called MD-DATA1 and MD-DATA2 have been developed, but the video camera of this example is capable of recording at higher density than MD-DATA1. It is assumed that recording and reproduction are performed in accordance with the format. So first, MD
-Disc format of DATA2 will be described.

FIGS. 1 and 2 conceptually show an example of a track structure of a disk as MD-DATA2. FIGS. 2A and 2B are a cross-sectional view and a plan view, respectively, showing an enlarged portion enclosed by a broken line A in FIG. As shown in these figures, two types of grooves (grooves) are previously formed on the disk surface: a wobbled groove WG provided with wobbles (meandering) and a non-wobbled groove NWG provided with no wobble. It is formed. The wobbled groove WG and the non-wobbled groove NWG
Exist in a double spiral on the disk so as to form a land Ld therebetween.

In the MD-DATA2 format, the land Ld is used as a track. Since the wobbled groove WG and the non-wobbled groove NWG are formed as described above, the track Tr / A is used as the track. , Tr and B are independently formed in a double spiral (double spiral) shape. The track Tr · A is a track in which the wobbled groove WG is located on the outer peripheral side of the disk and the non-wobbled groove NWG is located on the inner peripheral side of the disk. On the other hand, the track Tr · B is a track in which the wobbled groove WG is located on the inner peripheral side of the disk and the non-wobbled groove NWG is located on the outer peripheral side of the disk. In other words, it can be considered that a wobble is formed only on one side on the outer peripheral side of the disk for the track Tr.A, and a wobble is formed only on one side on the inner peripheral side of the disk for the track Tr.B. . In this case, the track pitch is the track Tr adjacent to each other.
・ It is the distance between each center of A and track Tr ・ B,
The track pitch is 0.95 μm as shown in FIG.
It has been.

Here, the wobbles formed in the groove as the wobbled groove WG are formed based on a signal in which the physical address on the disk is encoded by FM modulation + biphase modulation. Therefore, it is possible to extract the physical address on the disc by demodulating the reproduction information obtained from the wobbling given to the wobbled groove WG at the time of recording / reproduction. Further, the address information as the wobbled groove WG is commonly effective for the tracks Tr · A and Tr · B. In other words, the track Tr · A located on the inner periphery of the wobbled groove WG and the track Tr · B located on the outer periphery share the address information by the wobbling given to the wobbled groove WG. . Note that such an addressing scheme is also called an interlace addressing scheme. By adopting this interlace addressing method, for example, it is possible to reduce the track pitch while suppressing crosstalk between adjacent wobbles. For a method of recording an address by forming a wobble in a groove, A
Also called DIP (Adress In Pregroove) method.

The identification of which one of the tracks Tr.A and Tr.B sharing the same address information is being traced can be performed as follows. For example, in a state where the main beam is tracing a track (land Ld) by applying a three-beam method, the remaining two side beams trace grooves located on both sides of the track being traced by the main beam. It is possible to make it.

FIG. 2B shows a specific example in which the main beam spot SPm traces the track Tr · A. In this case, of the two side beam spots SPs1 and SPs2, the inner side beam spot SPs1 traces the non-wobbled groove NWG and the outer side beam spot S
Ps2 traces the wobbled groove WG. On the other hand, although not shown, if the main beam spot SPm traces the tracks Tr and B, the side beam spot SPs1 traces the wobbled groove WG and the side beam spot SP
s2 traces the non-wobbled groove NWG. Thus, the main beam spot SPm
Tracing the track Tr · A and the track T
In the case of tracing r · B, the grooves to be traced by the side beam spots SPs1 and SPs2 are necessarily replaced by the wobbled groove WG and the non-wobbled groove NWG.

Side beam spots SPs1, SPs2
As a detection signal obtained by the photodetector due to the reflection of light, different waveforms are obtained depending on which of the wobbled groove WG and the non-wobbled groove NWG is being traced. By determining which of the side beam spots SPs1 and SPs2 traces the wobbled groove WG (or the non-wobbled groove NWG), the main beam is moved to the tracks Tr · A,
Which of Tr and B is being traced can be identified.

FIG. 3 shows the main specifications of the MD-DATA2 format having the track structure as described above.
It is a figure shown in comparison with D-DATA1 format.
First, in the MD-DATA1 format, the track pitch is 1.6 μm and the pit length is 0.59 μm / bi.
t. The laser wavelength λ is set to 780 nm, and the aperture ratio NA of the optical head is set to 0.45. As a recording method, a groove recording method is adopted. That is, the groove is used as a track for recording and reproduction. As a method of addressing, a method of forming a groove (track) by a single spiral and using a wobbled groove in which wobbles are formed as address information on both sides of the groove is adopted.

As a modulation method of recording data, EFM (8
-14 conversion). As an error correction method, ACIRC (Advanced Cross Interleave Reed-
Solomon Code) and a convolutional data interleave. Therefore, the data redundancy is 46.3%.

In the MD-DATA1 format, a CLV (Constant Linear V) is used as a disk drive system.
erocity) is adopted, and the linear velocity of CLV is
1.2 m / s. The standard data rate during recording and reproduction is 133 kB / s, and the recording capacity is 140 MB.

On the other hand, the MD-DATA2 format which can be supported by the video camera of this embodiment has a track pitch of 0.95 μm and a pit length of 0.39 μm / b.
It can be seen that both are shorter than the MD-DATA1 format. For example, in order to realize the pit length, the laser wavelength λ = 650 nm and the aperture ratio NA of the optical head are set to 0.52, thereby narrowing the beam spot diameter at the in-focus position and expanding the band as an optical system. .

As described with reference to FIGS. 1 and 2, a land recording method is adopted as a recording method, and an interlace addressing method is adopted as an address method. As a modulation method of recording data, an RLL (1,7) method (RLL;
Run Length Limited), an RS-PC method is used as an error correction method, and a block complete type is used as data interleaving. As a result of adopting each of the above methods, the data redundancy can be suppressed to 19.7%.

Also in the MD-DATA2 format, CLV is adopted as a disk drive system, but its linear velocity is 2.0 m / s, and the standard data rate for recording / reproducing is 589 kB / s. It is said. As a result, a recording capacity of 650 MB can be obtained. Compared with the MD-DATA1 format, this means that a high-density recording of almost four times is realized. For example, assuming that a moving image is to be recorded in the MD-DATA2 format, MPEG
In the case where the compression encoding by 2 is performed, it is possible to record a moving image of 15 minutes to 17 minutes in time, depending on the bit rate of the encoded data. Also, assuming that only audio signal data is recorded, the ATR
When a compression process using AC (Adaptive Transform Acoustic Coding) 2 is performed, recording can be performed for about 10 hours.

2. 6A, 6B, and 6C are a side view, a plan view, and a rear view showing an example of the appearance of the video camera of this example. As shown in these figures, the main body 200 of the video camera of the present embodiment includes:
A camera lens 201 provided with an imaging lens and a diaphragm for taking a picture is provided so as to be exposed. A pair of left and right microphones 202 is provided. That is, in this video camera, recording of an image taken by the camera lens 201 and
It is possible to record stereo sound collected by the microphone 202.

The display unit 6 is provided on the side of the main body 200.
A, a speaker 205 and an indicator 206 are provided. The display unit 6A is a part that displays and outputs a captured image, an image reproduced by an internal recording and reproducing device, and the like. The display device actually used as the display unit 6A is not particularly limited here,
For example, a liquid crystal display or the like may be used. Also,
The display unit 6A also displays a message such as characters or characters for notifying the user of a required message in accordance with the operation of the device. Speaker 20
5 reproduces the recorded voice when reproducing the recorded voice, and also outputs a required message voice such as a beep sound. The indicator 206 emits light during a recording operation, for example, to indicate to the user that the video camera is performing a recording operation.

A viewfinder 204 is provided on the back side of the main body 200, and displays an image taken from the camera lens 201, a character image, and the like during a recording operation and a standby state. The user can shoot while looking at the viewfinder 204. Further, the disc slot 203, the video output terminal T
1. A headphone / line terminal T2 and an I / F terminal T3 are provided. The disk slot 203 is a slot portion for inserting or ejecting a disk as a recording medium corresponding to the video camera of this example. The video output terminal T1 is a terminal for outputting a reproduced image signal or the like to an external video device, and the headphone / line terminal T2 is a terminal for outputting a reproduced audio signal to an external audio device or headphones. The I / F terminal T3 is, for example, an input / output terminal of an interface for performing data transmission with an external data device.

Further, various controls (300 to 309) for user operation are provided in each part of the main body 200. The main dial 300 is for turning on / off the video camera.
An operator for setting off, recording operation, and reproduction operation. When the main dial is at the "OFF" position as shown in the figure, the power is off. When the main dial is turned to the "STBY" position, the power is turned on and the recording operation is in a standby state. Further, by turning to the position of “PB”, the power is turned on and a standby state of the reproducing operation is set.

The release key 301 functions as a recording start or recording shutter operator when in a recording standby state.

A zoom key 304 is an operator for operating a zoom state (tele side to wide side) regarding image shooting. The eject key 305 is
This is an operator for ejecting the disc loaded in the inside. Play / pause key 306, stop key 307,
Search keys 308 and 309 are prepared for various operations during reproduction with respect to the disc.

The search keys 308 and 30 of this embodiment are particularly
As the operation of No. 9, for example, search keys 308, 309
Is pressed once, and then the pressing operation is released within a predetermined time, the file number is incremented one by one in accordance with the currently set file reproduction order (by the search key 309). Case) or the file of the decremented number (in the case of the search key 308) is called up. If the search key 308 is continuously pressed for a predetermined time or more, the current playback moving image (and audio) in one file is played back by fast rewind, and the search key 309 is continuously pressed for the predetermined time or more. If the operation has been performed, the current playback moving image (and audio) in one file is played back by fast forward.

The after-recording key 310 is used for image data such as recorded video once recorded on a disc.
It is provided for setting a post-recording mode when recording a so-called post-recording sound to be reproduced later in synchronization with the reproduction time of the image data.

Note that the appearance of the video camera shown in FIG. 6 is merely an example, and may be appropriately changed according to the use conditions and the like actually required for the video camera of this embodiment. Of course, various types of operation elements, operation methods, and connection terminals with external devices can be considered.

3. FIG. 4 is a block diagram showing an example of the internal configuration of the video camera of the present embodiment. The lens block 1 shown in FIG. 1 includes, for example, an optical system 11 actually including an imaging lens and a diaphragm. The camera lens 201 shown in FIG. 6 is included in the optical system 11. The lens block 1 includes a focus motor for causing the optical system 11 to perform an autofocus operation, a zoom motor for moving the zoom lens based on the operation of the zoom key 304, and the like.
Provided as

The camera block 2 is provided with a circuit section for mainly converting image light captured by the lens block 1 into a digital image signal. For the CCD (Charge Coupled Device) 21 of the camera block 2,
An optical image of the subject transmitted through the optical system 11 is provided. C
In the CD 21, an image pickup signal is generated by performing photoelectric conversion on the optical image, and a sample hold / AGC (A
utomatic Gain Control) circuit 22. The sample hold / AGC circuit 22 adjusts the gain of the imaging signal output from the CCD 21 and performs waveform shaping by performing sample hold processing. The output of the sample hold / AGC circuit 2 is a video A / D
By being supplied to the converter 23, it is converted into digital image signal data.

The above CCD 21, sample hold / AG
Signal processing timing in the C circuit 22 and the video A / D converter 23 is controlled by a timing signal generated by a timing generator 24. The timing generator 24 receives a clock used for signal processing in a data processing / system control circuit 31 (in the video signal processing circuit 3) described later and generates a required timing signal based on the clock. Is done. Thereby, the signal processing timing in the camera block 2 is synchronized with the processing timing in the video signal processing unit 3. Camera controller 2
Reference numeral 5 is for performing necessary control so that each of the functional circuit units provided in the camera block 2 operates properly, and for performing autofocus, automatic exposure adjustment, aperture adjustment, zooming, and the like on the lens block 1. Is controlled. For example, in the case of auto-focus control, the camera controller 25 performs, based on focus control information obtained in accordance with a predetermined
Controls the rotation angle of the focus motor. As a result, the imaging lens is driven to be in the just-focused state.

At the time of recording, the video signal processing unit 3 performs a compression process on the digital image signal supplied from the camera block 2 and the digital audio signal obtained by collecting sound by the microphone 202, and compresses the compressed data. The data is supplied to the subsequent media drive unit 4 as user recording data. Further, an image generated from the digital image signal and the character image supplied from the camera block 2 is supplied to the viewfinder drive unit 207 and displayed on the viewfinder 204. Further, at the time of reproduction, demodulation processing is performed on user reproduction data (data read from the disk 51) supplied from the media drive unit 4, that is, image signal data and audio signal data that have been subjected to compression processing, and these are reproduced. , And output as a reproduced audio signal.

In this embodiment, as a compression / expansion processing method of image signal data (image data), MPEG (Moving Picture Experts Group) 2 is adopted for moving images, and JPEG (Joint Photographic) is applied for still images.
Coding Experts Group). The audio signal data compression / expansion processing method includes ATR
AC (Adaptive Transform Acoustic Coding) 2 shall be adopted.

The data processing / system control circuit 31 of the video signal processing section 3 mainly performs control processing relating to compression / expansion processing of image signal data and audio signal data in the video signal processing section 3 and video signal processing section 3. Executes the process for controlling the input and output of data passing through. The data processing / system control circuit 31
The control processing for the entire video signal processing unit 3 including
The video controller 38 is made to execute. The video controller 38 includes, for example, a microcomputer and the like, and can communicate with the camera controller 25 of the camera block 2 and a driver controller 46 of the media drive unit 4 described later via, for example, a bus line (not shown). Have been.

As a basic operation at the time of recording in the video signal processing unit 3, image signal data supplied from the video A / D converter 23 of the camera block 2 is input to the data processing / system control circuit 31. The data processing / system control circuit 31 supplies the input image signal data to, for example, the motion detection circuit 35. The motion detection circuit 35 performs image processing such as motion compensation on the input image signal data while using the memory 36 as a work area, and then supplies the processed image signal data to the MPEG2 video signal processing circuit 33.

In the MPEG2 video signal processing circuit 33, for example, while using the memory 34 as a work area, the input image signal data is subjected to compression processing in accordance with the MPEG2 format, and a bit stream of compressed data as a moving image (MPEG2 Bit stream). In the MPEG2 video signal processing circuit 33, for example, when extracting image data as a still image from image signal data as a moving image and performing compression processing on the extracted image data, the compressed image data as a still image in accordance with the JPEG format is used. Is configured to generate It should be noted that JPEG was not adopted and MPEG
As compressed image data in the second format, an I picture (Intra Picture), which is regular image data, may be treated as still image data. MPEG
The image signal data (compressed image data) compressed and encoded by the two-video signal processing circuit 33 is written into the buffer memory 32 at a predetermined transfer rate and temporarily stored. In the MPEG2 format, as is well known, a so-called encoding bit rate (data rate) is used as a constant bit rate (CBR).
ate) and a variable bit rate (VBR), and the video signal processing unit 3 can cope with these.

The audio compression encoder / decoder 37 includes:
A / D converter 64 (display / image / audio input / output unit 6)
For example, the sound collected by the microphone 202 is input as digital sound signal data. The audio compression encoder / decoder 37 performs compression processing on the input audio signal data in accordance with the ATRAC2 format as described above. This compressed audio signal data is also written into the buffer memory 32 by the data processing / system control circuit 31 at a predetermined transfer rate, and is temporarily stored here.

As described above, the compressed image data and the compressed audio signal data can be stored in the buffer memory 32. The buffer memory 32 mainly absorbs a speed difference between the data transfer rate between the camera block 2 or the display / image / audio input / output unit 6 and the buffer memory 32 and the data transfer rate between the buffer memory 32 and the media drive unit 4. Has a function for Buffer memory 3
The compressed image data and the compressed audio signal data stored in 2 are read out sequentially at a predetermined timing during recording, and transmitted to the MD-DATA2 encoder / decoder 41 of the media drive unit 4. However, for example, during the reproduction, the reading of the data stored in the buffer memory 32 and the operation of recording the read data from the media drive unit 4 to the disk 51 via the deck unit 5 are performed intermittently. No problem. Such control of writing and reading data to and from the buffer memory 32 is executed by, for example, the data processing / system control circuit 31.

The operation at the time of reproduction in the video signal processing section 3 is roughly as follows. At the time of reproduction, compressed image data and compressed audio signal data (user reproduction data) read from the disk 51 and decoded according to the MD-DATA2 format by the processing of the MD-DATA2 encoder / decoder 41 (in the media drive unit 4) Data processing / system control circuit 31
Will be transmitted. The data processing / system control circuit 31 temporarily stores the input compressed image data and compressed audio signal data in the buffer memory 32, for example. Then, the compressed image data and the compressed audio signal data are read from the buffer memory 32 at a required timing and at a transfer rate at which the reproduction time axis can be matched.
The compressed audio signal data is supplied to the video signal processing circuit 33, and the compressed audio signal data is supplied to the audio compression encoder / decoder 37.

In the MPEG2 video signal processing circuit 33,
Decompresses the input compressed image data,
It is transmitted to the data processing / system control circuit 31. In the data processing / system control circuit 31,
The expanded image signal data is supplied to the video D / A converter 61 (in the display / image / audio input / output unit 6). The audio compression encoder / decoder 37 performs an expansion process on the input compressed audio signal data,
/ A converter 65 (in display / image / audio input / output unit 6)
To supply.

In the display / image / audio input / output unit 6,
The image signal data input to the video D / A converter 61 is converted into an analog image signal here, and is branched and input to the display controller 62 and the composite signal processing circuit 63. The display controller 62 drives the display unit 6A based on the input image signal. As a result, a reproduced image is displayed on the display unit 6A. Further, in the display unit 6A, not only an image obtained by reproducing from the disk 51 but also a captured image obtained by photographing with a camera part including the lens block 1 and the camera block 2 is naturally displayed. It is possible to display and output almost in real time. Further, in addition to the reproduced image and the captured image, as described above, a message display such as a character or a character for notifying the user of a required message in accordance with the operation of the device is also performed. Such a message display should be output from the data processing / system control circuit 31 to the video D / A converter 61 so that required characters, characters, and the like are displayed at predetermined positions under the control of the video controller 38, for example. Processing for synthesizing image signal data of required characters, characters, and the like may be performed on the image signal data.

The composite signal processing circuit 63 converts the analog image signal supplied from the video D / A converter 61 into a composite signal and outputs it to the video output terminal T1. For example, if a connection is made to an external monitor device or the like via the video output terminal T1, an image reproduced by the video camera can be displayed on the external monitor device.

In the display / image / audio input / output section 6, the audio signal data input from the audio compression encoder / decoder 37 to the D / A converter 65 is converted into an analog audio signal here, and the signals are supplied to a headphone / line terminal. T
2 is output. In addition, the analog audio signal output from the D / A converter 65 is also branched and output to the speaker SP via the amplifier 66, whereby the reproduced audio and the like are output from the speaker SP. Become.

At the time of recording, the media drive section 4 encodes the recording data in accordance with the MD-DATA2 format so as to conform to the disc recording and transmits the encoded data to the deck section 5. By performing decoding processing on the read data, reproduced data is obtained and transmitted to the video signal processing unit 3.

The MD-DAT of the media drive unit 4
When recording, the A2 encoder / decoder 41
Recording data (compressed image data + compressed audio signal data) is input from the data processing / system control circuit 31, the recording data is subjected to a predetermined encoding process in accordance with the MD-DATA2 format, and the encoded data is temporarily stored. The data is stored in the buffer memory 42. Then, the data is transmitted to the deck unit 5 while being read at a required timing.

At the time of reproduction, the digital reproduction signal read from the disk 51 and input through the RF signal processing circuit 44 and the binarization circuit 43 is subjected to MD-DAT.
A decoding process according to the A2 format is performed, and the data is transmitted to the data processing / system control circuit 31 of the video signal processing unit 3 as reproduction data. Also at this time, if necessary, the reproduced data is temporarily stored in the buffer memory 42, and the data read therefrom at a required timing is transmitted to the data processing / system control circuit 31 for output. Such writing / reading control for the buffer memory 42 is performed by the driver controller 46. Note that, for example, when the servo is disengaged due to disturbance or the like during reproduction of the disk 51 and reading of a signal from the disk becomes impossible, the read data is stored in the buffer memory 42 during the period during which the read data is accumulated. If the reproduction operation for the disc is resumed, the chronological continuity as the reproduction data can be maintained.

The RF signal processing circuit 44 includes a disk 51
By performing the required processing on the read signal from
For example, it generates an RF signal as reproduction data, a servo control signal such as a focus error signal and a tracking error signal for servo control of the deck unit 5, and the like. RF
The signal is binarized by the binarization circuit 43 as described above, and input to the MD-DATA2 encoder / decoder 41 as digital signal data. The generated various servo control signals are supplied to the servo circuit 45. In the servo circuit 45, based on the input servo control signal,
The required servo control in the deck section 5 is executed.

In this example, MD-DATA1
An encoder / decoder 47 corresponding to the format is provided. The encoder / decoder 47 encodes the recording data supplied from the video signal processing unit 3 in accordance with the MD-DATA1 format and records the encoded data on the disk 51. It is also possible to perform decoding processing on data encoded in accordance with the MD-DATA1 format, and transmit and output it to the video signal processing unit 3. That is, as the video camera of this example, the MD-DATA2 format and the MD-DATA2 format are used.
It is configured to obtain compatibility with the DATA1 format. The driver controller 46 is a functional circuit unit for controlling the media drive unit 4 as a whole.

The deck section 5 is a part comprising a mechanism for driving the disk 51. Although not shown here, in the deck section 5, the disk 5 to be loaded is
1 is detachable and has a mechanism (disc slot 203 (see FIG. 6)) that can be replaced by a user's work. Further, it is assumed that the disk 51 here is a magneto-optical disk corresponding to the MD-DATA2 format or the MD-DATA1 format.

In the deck section 5, a spindle motor 5 for rotating the loaded disk 51 by CLV is used.
2 is driven to rotate by the CLV. The optical head 53 irradiates the disk 51 with laser light during recording / reproduction. The optical head 53 performs high-level laser output for heating the recording track to the Curie temperature during recording, and performs relatively low-level laser output for detecting data from reflected light by the magnetic Kerr effect during reproduction. . Therefore, the optical head 53
Although not shown in detail here, a laser diode as a laser output unit, an optical system including a polarizing beam splitter and an objective lens, and a detector for detecting reflected light are mounted. The objective lens provided in the optical head 53 is held by a biaxial mechanism so as to be displaceable in a radial direction of the disk and in a direction of coming and coming from the disk.

The optical head 5 with the disk 51 interposed therebetween
A magnetic head 54 is arranged at a position facing 3. The magnetic head 54 performs an operation of applying a magnetic field modulated by recording data to the disk 51. Although not shown, the thread motor 55
And a thread mechanism driven by the thread mechanism. By driving the sled mechanism, the entire optical head 53 and the magnetic head 54 can be moved in the disk radial direction.

The operation unit 7 is provided with each of the operators 300 to
310, etc., and various operation information of the user by these operators is supplied to, for example, the video controller 38. The video controller 38 supplies, to the camera controller 25 and the driver controller 46, operation information and control information for causing each unit to execute necessary operations according to a user operation.

The external interface 8 is provided so that data can be transmitted between the video camera and the external device. For example, as shown in FIG. Can be The external interface 8 is not particularly limited here, but may be, for example, IEEE 1394 or the like. For example, when an external digital imaging device and the video camera of this embodiment are connected via the I / F terminal T3, it becomes possible to record an image (audio) captured by the video camera on the external digital imaging device. . In addition, image (sound) data reproduced by an external digital image device or the like is captured via the external interface 8 so that MD-
It is also possible to record on the disk 51 in accordance with the DATA2 (or MD-DATA1) format.

The power supply block 9 supplies a required level of power supply voltage to each functional circuit unit using a DC power supply obtained from a built-in battery or a DC power supply generated from a commercial AC power supply. The power supply on / off by the power supply block 9 is controlled by the video controller 38 in accordance with the operation of the main dial 300 described above. During the recording operation, the video controller 38 causes the indicator 206 to emit light.

4. Configuration of Media Drive Unit Next, as the configuration of the media drive unit 4 shown in FIG. 4, a detailed configuration in which a functional circuit unit corresponding to MD-DATA2 is extracted will be described with reference to the block diagram of FIG. In FIG. 5, the deck unit 5 is shown together with the media drive unit 4. However, since the internal configuration of the deck unit 5 has been described with reference to FIG. 4, the same reference numerals as in FIG. I do. In the media drive unit 4 shown in FIG. 5, the same reference numerals are given to the ranges corresponding to the blocks in FIG.

Information detected by the data reading operation of the optical head 53 from the disk 51 (photocurrent obtained by detecting laser reflected light by a photodetector)
Is supplied to the RF amplifier 101 in the RF signal processing circuit 44. The RF amplifier 101 generates a reproduction RF signal as a reproduction signal from the input detection information and supplies the reproduction RF signal to the binarization circuit 43. The binarization circuit 43 binarizes the input reproduction RF signal to obtain a digital reproduction RF signal (binary RF signal). This binarized RF signal is supplied to the MD-DATA2 encoder / decoder 41, and first, the AGC / clamp circuit 103
Are input to the equalizer / PLL circuit 104 after gain adjustment, clamp processing, and the like have been performed. The equalizer / PLL circuit 104 performs an equalizing process on the input binary RF signal, and
5 is output. In addition, binarization R after equalizing processing
By inputting the F signal to the PLL circuit, the binarized RF
Clock C synchronized with signal (RLL (1,7) code string)
Extract LK.

The frequency of the clock CLK corresponds to the current disk rotation speed. Therefore, the CLV processor 11
1, the clock C is output from the equalizer / PLL circuit 104.
LK is input, error information is obtained by comparing with a reference value corresponding to a predetermined CLV speed (see FIG. 3), and this error information is used as a signal component for generating a spindle error signal SPE. Further, the clock CLK includes, for example, the RLL (1, 7) demodulation circuit 106 and the like.
It is used as a clock for processing in a required signal processing circuit system.

The Viterbi decoder 105 has an equalizer / P
The binary RF signal input from the LL circuit 104 is subjected to a decoding process according to a so-called Viterbi decoding method. As a result, reproduced data as an RLL (1, 7) code string is obtained. This reproduced data is RLL (1,
7) The signal is input to the demodulation circuit 106, where RLL (1,
7) The data stream is subjected to demodulation.

The data stream obtained by the demodulation processing in the RLL (1, 7) demodulation circuit 106 is written to the buffer memory 42 via the data bus 114 and is developed on the buffer memory 42. The data stream expanded on the buffer memory 42 in this manner is first subjected to error correction processing in error correction block units according to the RS-PC system by the ECC processing circuit 116, and further descramble / E
The DC decoding circuit 117 performs a descrambling process and an EDC decoding process (error detection process). The data processed so far is the reproduction data DA
TAp. The reproduction data DATAp is transmitted at a transfer rate according to the transfer clock generated by the transfer clock generation circuit 121, for example, from the descrambling / EDC decoding circuit 117 to the data processing / processing of the video signal processing unit 3.
The data is transmitted to the system control circuit 31.

The transfer clock generation circuit 121 is, for example,
When a crystal clock is used for data transmission between the media drive unit 4 and the video signal processing unit 3 and data transmission between functional circuit units in the media drive unit 4,
This is a portion for generating a transfer clock having a frequency appropriately determined.

The detection information (photocurrent) read from the disk 51 by the optical head 53 is transmitted to the matrix amplifier 1
07 is also supplied. The matrix amplifier 107 performs required arithmetic processing on the input detection information, thereby obtaining a tracking error signal TE, a focus error signal FE, and groove information (absolute address information recorded as a wobbled groove WG on the disk 51) GFM. Are supplied to the servo circuit 45. That is, the extracted tracking error signal TE and focus error signal FE are supplied to the servo processor 112, and the groove information GFM is stored in the ADIP bandpass filter 108.
Supplied to

The groove information GFM band-limited by the ADIP band-pass filter 108 is supplied to an A / B track detection circuit 109, an ADIP decoder 110, and a CLV.
It is supplied to the processor 111. In the A / B track detecting circuit 109, based on the input groove information GFM, for example, the track currently being traced is determined based on the method described with reference to FIG.
A, TR or B is determined, and the track determination information is transmitted to the driver controller 46.
Output to The ADIP decoder 110 decodes the input groove information GFM to extract an ADIP signal, which is absolute address information on the disk, and outputs the signal to the driver controller 46. The driver controller 46 executes necessary control processing based on the track identification information and the ADIP signal.

The CLV processor 111 receives the clock CLK from the equalizer / PLL circuit 104 and the groove information GFM via the ADIP bandpass filter 108. The CLV processor 111 generates a spindle error signal SPE for CLV servo control based on, for example, an error signal obtained by integrating a phase error between the groove information GFM and the clock CLK, and outputs the spindle error signal SPE to the servo processor 112. The required operation to be executed by the CLV processor 111 is controlled by the driver controller 46.

The servo processor 112 performs various servo control signals on the basis of the tracking error signal TE, focus error signal FE, spindle error signal SPE, track jump command and access command from the driver controller 46 input as described above. (A tracking control signal, a focus control signal, a thread control signal, a spindle control signal, and the like) are generated and output to the servo driver 113. In the servo driver 113,
A required servo drive signal is generated based on the servo control signal supplied from the servo processor 112. Here, the servo drive signal includes a two-axis drive signal (two types of focus direction and tracking direction) for driving the two-axis mechanism, a sled motor drive signal for driving the sled mechanism, and a spindle motor drive signal for driving the spindle motor 52. Becomes By supplying such a servo drive signal to the deck section 5, focus control and tracking control on the disk 51 and CLV control on the spindle motor 52 are performed.

When a recording operation is performed on the disk 51, for example, the data processing /
Scramble / ED from system control circuit 31
The recording data DATAR for the C encoding circuit 115
Will be input. This user record data DAT
Ar is input in synchronization with, for example, a transfer clock generated by the transfer clock generation circuit 121.

Scramble / EDC encoding circuit 11
In step 5, for example, the recording data DATAR is written into the buffer memory 42 and developed,
DC encoding processing (addition processing of an error detection code by a predetermined method) is performed. After this processing, for example, the ECC processing circuit 116 adds an error correction code according to the RS-PC method to the recording data DATAR developed in the buffer memory 42. The recording data DATAR that has been processed up to this point is read from the buffer memory 42 and transmitted to the RL via the data bus 114.
The signal is supplied to the L (1, 7) modulation circuit 118.

In the RLL (1, 7) modulation circuit 118, RLL (1, 7) is applied to the input recording data DATAR.
7) A modulation process is performed, and the recording data as the RLL (1, 7) code string is output to the magnetic head drive circuit 119.

Incidentally, the MD-DATA2 format employs a so-called laser strobe magnetic field modulation system as a recording system for a disk. The laser strobe magnetic field modulation method refers to a recording method in which a magnetic field modulated by recording data is applied to a recording surface of a disk, and a laser beam to be irradiated on the disk is pulsed in synchronization with the recording data. In such a laser strobe magnetic field modulation method, the process of forming a pit edge recorded on a disk does not depend on transient characteristics such as the reversal speed of a magnetic field, but is determined by the laser pulse irradiation timing. For this reason, the laser strobe magnetic field modulation method is compared with, for example, a simple magnetic field modulation method (a method in which a laser beam is constantly irradiated onto a disk and a magnetic field modulated by recording data is applied to a disk recording surface). In this case, it is possible to make the jitter of the recording pit extremely small. That is, the laser strobe magnetic field modulation method is a recording method advantageous for high-density recording.

The magnetic head drive circuit 119 of the media drive unit 4 operates so that a magnetic field modulated by the input recording data is applied from the magnetic head 54 to the disk 51. Further, the RLL (1, 7) modulation circuit 118 outputs a clock synchronized with the recording data to the laser driver 120. The laser driver 120 controls the optical head 5 so that the disk is irradiated with a laser pulse synchronized with recording data generated as a magnetic field by the magnetic head 54 based on the input clock.
The third laser diode is driven. At this time, the laser pulse emitted and output from the laser diode is based on a required laser power suitable for recording. In this way, the recording operation as the laser strobe magnetic field modulation method is enabled by the media drive unit 4 of the present embodiment.

5. Next, a description will be given of an example of the structure of a disk 51 according to the present embodiment. FIG. 7 conceptually shows an example of an area structure of a disk 51 which is assumed to correspond to the present embodiment. Note that the physical format of the disk 51 shown in this figure is as described above with reference to FIGS. As shown in FIG. 7, in the magneto-optical recording area where the magneto-optical recording and reproduction can be performed as the disk 51, first, a management area is provided for a section of a predetermined size at the innermost circumference. This management area is, for example, U-TOC
Required management information referred to as (user TOC), which is required for managing the recording and reproduction of files on the disc, is mainly recorded. For example, information for managing the reproduction order for each file is also recorded here. . Further, the contents of the U-TOC in the management area can be sequentially rewritten according to, for example, addition or deletion of a file recorded on a disc, or an editing operation for changing the reproduction order by a user as described later. You. In particular, in the present embodiment, as a type of U-TOC, a U-TOC having a data structure for managing a data file as a moving image in packet units as described later is provided. . In addition, management information indicating the correspondence between a file such as a moving image recorded in the data area described later and an after-recording file recorded in the after-recording area is stored in the U-TOC for performing file-by-file management. Shall be stored.

A data area is provided on the outer peripheral side of the management area. In this data area, for example, image data and audio data recorded and recorded by the user are recorded. The data recorded in the data area is recorded in a form managed on a file basis. The recording and reproduction of data for each file is managed based on management information stored in the management area.

An after-recording area is provided on the outer peripheral side of the data area. In the present embodiment, for example, a so-called after-recording (after-recording) function is provided in which audio is additionally recorded while reproducing (displaying and outputting) a moving image file already recorded on the disk 51 as described later. ing. In the post-recording area, post-record audio data recorded by the post-recording function is recorded. The audio dubbing recorded as described above has a data structure to be described later, so that when the file is reproduced, the audio recording timing of the audio dubbing corresponding to the reproduced image displayed during the audio dubbing recording (input time) At the same timing as (timing), it is possible to reproduce and output in synchronization with the reproduced image.

The example of the disk structure shown in this figure is merely an example, and the physical positional relationship of each area in the disk radial direction may be changed according to the actual use conditions and the like. If necessary, an area for storing data of some other content may be additionally provided.

6. Packet 6-1. Packet Structure In the case of recording a moving image on the disk 51 in the video camera of the present embodiment, the moving image data is subjected to compression encoding by MPEG2 as described above. In the MPEG2 format, as described above, CBR (fixed bit rate) and VBR (variable bit rate) are supported as encoding bit rates (data rates). In order to increase the recording time so as to obtain as long a recording time as possible, it is preferable to employ VBR.

However, when moving image data is compressed by VBR, the data unit called GOP, which is originally the minimum unit of special reproduction and editing processing in the MPEG2 format, has a variable length. For this reason, when the actual VBR is adopted, the structure of management information for managing the variable length GOP and the data processing in GOP units become complicated. It has been found that it is difficult to manage data in such a case and to reproduce data on the premise of special reproduction and various editing processes.

Therefore, in this example, even when VBR is adopted as the MPEG2 format, a data reproduction operation including special reproduction and editing processing can be easily realized based on a simple data management form. Data recording is performed as described below.

Here, in the following description, in the video camera of the present example, of the moving image data and the audio data obtained through the recording operation or the external interface 8, for example, the moving image data is converted by VBR in the MPEG2 format. It is assumed that compression processing is performed. The audio data is subjected to compression processing by ATRAC2.

In this example, the compressed image data and the compressed audio data obtained as described above are divided in time series, and the divided compressed image data and compressed audio data are divided into The data is stored in a fixed-length data unit as a “packet”, and moving image and audio data are recorded on a disk by the sequence of the packet. The compressed image data recorded in the packet is in GOP units.

Here, the setting of the data capacity of one packet in this example will be considered. First, compressed audio data subjected to compression processing by ATRAC2 has a fixed bit rate of 0.115 Mbps. MPE
As the VBR of the G2 format, the maximum bit rate is set to 4.8 Mbps, and the minimum bit rate is set to 3.8 Mbps. The average bit rate is usually 4 Mbps.

Here, in this example, the compressed moving image and compressed audio data stored in one packet are set to 2
It is assumed that a capacity sufficient to secure a data recording time of second or more is obtained.

Considering the total amount of data consisting of a compressed moving image and compressed data corresponding to 2 seconds, the compressed moving image data: minimum bit rate (3.8 Mbit + 0.115 Mbit) × 2 (seconds) =
7.83 Mbit, compressed moving image data; average bit rate (4 Mbit + 0.115 Mbit) × 25 = 8.23
Mbit, compressed video data; at maximum bit rate (4.8 Mbit + 0.115 Mbit) × 2 (seconds) =
9.83 Mbit. As can be seen from this, recording data (moving image and audio data) corresponding to 2 seconds for one packet even at the maximum bit rate of the compressed moving image data
In order to be able to store the data, the capacity of one packet to be fixed length needs to be at least 9.83 Mbit. Therefore, in this example, one packet is set to have a fixed length of 10 Mbit by giving a certain margin to the above 9.83 Mbit.

Here, the recordable time for a packet having a capacity of 10 Mbit is 10 Mbit / (3.8 Mbit + 0.115 Mbi) when the compressed moving image data has the minimum bit rate.
t) ≒ 2.55 (seconds), and under this condition, the data recording time per packet becomes the maximum. Further, when the compressed moving image data has an average bit rate (4 Mbps), 10 Mbit / (4 Mbit + 0.115 Mbit) ≒
2.43 (seconds). This is the average value of the data recording time per packet. Then, when the compressed moving image data is at the maximum bit rate, 10 Mbit / (4.8 Mbit + 0.115 Mbi)
t) ≒ 2.03 (sec), and under this condition, the data recording time per packet is minimized.

FIG. 8 shows an example of the data structure of such a packet of this example. For example, taking the packet 1 shown in FIG. 8A as an example, one packet has a fixed length of 10 Mbit as described above. It consists of a storage area.

The audio data storage area is an area in which compressed audio data compressed by ATRAC2 as recording data is stored. In this case, a fixed length of 0.3 Mb is used.
The size of the it is assigned. This 0.3Mbi
As a basis for setting t, as described above, when the data rate of the compressed moving image data is the minimum, the recording time for one packet is the maximum at 2.55 seconds. From this, the audio data storage area is: 0.115 Mbps × 2.55 (seconds) ≒ 0.293 Mb
It is only necessary to secure 0.293 Mbit as shown by “it”.
It is 3 Mbit.

As a result, a fixed-length size of 9.7 Mbit is allocated to the image data storage area as shown by 10 Mbit−0.3 Mbit = 9.7 Mbit. It is assumed that one GOP is stored in the image data storage area of the present example as image data compressed in the MPEG2 format. As is well known, a GOP is a minimum data unit at the time of reproduction / editing in the MPEG2 format, and includes at least one I-picture (Intra Picture; intra-frame coded image) at the head of the data position as complete information. , And other P-pictures (Predictive Pictur
e; forward prediction coded image) and B picture (Bidirec)
tuinarlly predictive Picture; bidirectional predictive coded picture).

As described above, in VBR, a GOP has a variable length according to the data rate of a moving image, and this variable length GOP is stored in an image data storage area in a packet. Therefore, for example, in the image data storage area shown in FIG. 8A, as a result, a GOP having a data amount appropriately different depending on the data rate and the recording time is stored within 9.7 Mbit, and as shown in FIG. As a result, an image data non-storage area is formed on the rear end position side in FIG.

The compressed audio data stored in the audio data storage area includes G stored in the same packet.
Since the sound corresponds to the reproduction time of the OP image, the recording time of the sound data is naturally G
It depends on the recording time of the OP. Therefore, the data capacity of the compressed audio data stored in the audio data storage area is G
It becomes variable so as to correspond to the recording time of the OP. 8A, an audio data non-storage area corresponding to the storage capacity of the compressed audio data is formed on the rear end position side of the audio data storage area. In addition,
Actually, dummy data or the like that can be separated from real data may be stored in the image data non-storage area and the audio data non-storage area.

Here, packets 2 and 3 shown in FIGS. 8 (b) and 8 (c) are sequentially connected in time series to packet 1 and subsequent packets shown in FIG. 8 (a).
In other words, the user record data is formed by, for example, connecting in the order of packet 1 → packet 2 → packet 3. Here, assuming that only GOPs are extracted and connected in the order of packet 1 → packet 2 → packet 3, a sequence as compressed image data in the MPEG2 format is obtained. Similarly, only compressed audio data is extracted. If connected, ATRA
Time series continuity of the compressed audio data by C2 is obtained. As the packet 2 in FIG. 8B, the compressed image data (GO
P) and compressed audio data are stored. As packet 3 in FIG. 8C, compressed image data (GOP) and compressed audio data are stored in a shorter recording time than packet 1. The state is shown.

In this example, the compressed image data (GOP) having a variable data rate is applied to the fixed-length packets in this manner.
And compressed audio data (the data rate is fixed), and data obtained by, for example, recording by a user according to a sequence composed of the packets is recorded on the disk 51 as described later. . This allows
In this example, it becomes possible to treat compressed image data that is originally of a variable length in accordance with the data rate as a data unit of a fixed length, for example, as described later in the U-TOC.
By managing on a packet basis above,
It is possible to realize random access for each GOP by simple processing. More specifically, for example, when accessing a certain packet whose recording position is physically separated from a certain packet in a data sequence, the fact that the packet has a fixed length is used, for example, in this example, The access may be performed by skipping in units of 10 Mbits.
This eliminates the need for complicated processing such as adding an OP data amount each time to obtain an access position.

Further, even after the data is read from the disk in packet units, the reproduction process is performed in data units of fixed-length packets until, for example, compressed image data (GOP) and audio data are extracted and decompressed from the packets. For example, the processing load can be reduced as compared with a case where the reproduction process is performed by directly handling a GOP with a variable data rate.

The structure of the packet is not limited to that shown in FIG. 8. For example, the image data storage area is provided at the head, and the audio data storage area is provided at the back of the image data storage area. It is possible to do so.

However, in the present example, when performing special operations such as cue / review by reproducing recorded data recorded on a disc, for example, as described later, the GOP of the GOP stored in the image data storage area in the packet will be described later. The first I picture and the compressed audio data stored in the audio data storage area of the same packet are read and used. For this reason, if the data structure of the packet from the audio data storage area to the image data storage area is used as in this example, the compressed audio data is first read from the audio data storage area at the head of a certain packet,
Subsequently, by performing a read process of reading the first I-picture of the GOP in the image data storage area, the address amount (data distance) to be moved when reading necessary data at the time of cue / review can be reduced. , It is possible to execute the readout process more quickly.

In the MPEG2 format, for example, a sequence header is actually added to the head of each GOP to form a sequence as compressed image data. The sequence header is defined in the MPEG2 format as functioning as an entry point used for cueing at the time of random access. In FIG. 8, GO
Although only P is shown and the sequence header is not stored, a GOP may be stored following the sequence header in the actual image data storage area. However, in the case of this example, at the time of random access at the time of special reproduction such as cue / review reproduction or edit reproduction, for example, as described later,
U-TOC for packet management is used, and in particular, a sequence header is not used. Also,
For example, even when an editing operation that requires a change in the reproduction order in units of packets is performed, rewriting of the contents of the sequence header is not performed, and the management information is rewritten. For example, if random access is performed in accordance with the MPEG2 format using a sequence header or the like, elements that cause technical difficulties will surface as described above. By avoiding the direct handling of the original data and managing the recording and reproduction of the compressed image data (and the compressed audio data) in fixed-length packet units, the GO can be performed even with simpler processing as described above.
Good random access performance for P units can be obtained.

6-2. Example of Packet Recording Method on Disk In this example, recording on the disk 51 is performed in packet units shown in FIG. Here, various methods for recording data on the disk in packet units are conceivable, and FIG. 9 shows an example thereof.

First, when recording one packet on a disk, the packet is divided into two as conceptually shown in FIG. 9A. Here, the symbols of the divided packets Pa and Pb are assigned to the divided packets obtained by dividing one packet into two. In addition,
In the present example, the data structure of each of the divided packets Pa and Pb is not particularly limited, but according to this recording method, the divided packets Pa and Pb have a capacity of one packet (10 Mbit). ) Is preferably the same data size (5 Mbit) obtained by dividing the data into two equal parts.

As described with reference to FIG. 1, in the disk corresponding to the present example, two tracks of the tracks Tr.A and Tr.B are independently formed in a double spiral. Therefore, in this example, on the premise of the disk format, the packet divided as shown in FIG. 9A is recorded as shown in FIG. 9A to FIG. 9B. .

In this case, for example, first, as shown in FIG.
Record continuously for In FIG. 9B, the track T
The area where the divided packet Pa is recorded in r · A is indicated by oblique lines. In this case, a case is shown in which recording is performed on tracks from the inner peripheral side to the outer peripheral side of the disk. Thereafter, a track change is performed on a track Tr / B adjacent to the track Tr / A on which the divided packet Pa is recorded in the radial direction of the disk, and the track Tr / B is changed.
9C, the divided packet Pb is recorded as shown in FIG. As a result, as indicated by the oblique lines in FIG. 9C, the data of one packet composed of the divided packets Pa and Pb is stored in the tracks Tr and A, which are adjacent to each other.
Recording is performed on the tracks Tr and B. Here, if the subsequent packet is to be recorded, for example, the divided packet Pa of the subsequent packet is
Writing is performed on the track Tr · A so as to be connected from the recording end position of the divided packet Pa shown in FIG. 9C, and subsequently, similarly, the divided packet Pb of the subsequent packet is divided into the divided packet Pb in FIG. The writing is performed on the tracks Tr and B in such a manner that writing is continued from the Pb recording end position.

When tracks on which data is recorded by the above-described recording method are linearly developed in accordance with the disk rotation direction, it can be considered that a recording state as shown in FIG. 10 is obtained. . FIG. 10 shows a state in which, for example, packets 1 and 2 are sequentially recorded. When the tracks are expanded in this way, it is conceptual only. For example, according to the recording order of ~ for each recording area, adjacent tracks Tr.
A, the tracks Tr and B, in a zigzag pattern, the divided packet Pa of the packet 1 (TrA) → the divided packet Pb of the packet 1 (TrB) → the divided packet Pa of the packet 2 (TrA) → Fragmented packet Pb of packet 2
It will appear that the recording is performed as in (Tr.B).

For example, without using the recording method as described above,
First, when the recording is continuously performed on the track Tr · A, and when it is determined that the entire area of the track Tr · A has been recorded, the track is switched and the data is written to the track Tr · B. Causes the following inconveniences. For example, in a state where data has been written to the area of the track Tr · A, the track Tr · B
If the recording position is inadvertently moved with respect to the adjacent track Tr.A due to an impact while data is being written to the track Tr.
Data is overwritten on A, and data recorded up to that time may be destroyed. In this case, the data destroyed in the track Tr.A is data recorded long before in the recording time, and the destruction of such data is, for example, a point at which the user cannot meet. Therefore, it must be avoided as much as possible.

Therefore, as described in this example, by performing recording by switching the tracks Tr.A and Tr.B for each certain write data unit, as described above, the adjacent tracks are written when writing data. Even if the recording position is inadvertently moved relative to (or a track that is close in the radial direction of the disc), data that may be destroyed can be very close in recording time. That is. Therefore, in consideration of the above-described purpose, in this example, the write data unit recorded while switching the tracks Tr.A and Tr.B is as shown in FIG. 9A. The packet does not need to be divided into two packets Pa and Pb. For example, it is conceivable that the write data unit is made larger and a sequence of one or more predetermined numbers of packets is used as the write data unit. However, in consideration of minimizing the degree of data destruction as described above, the adjacent tracks Tr · A, Tr · B
The data size that should be written discretely between
It is preferable to be as small as possible. For this reason, in this example,
The packet is divided into two packets Pa and Pb as write data units. Therefore, in this example, the packet may be divided into, for example, a larger number of divided packets, and recording may be performed in accordance with the operation shown in FIGS. 9B to 9C. May be determined in consideration of the data transfer rate at the time of disk writing, the time required for track change for track switching (access time), and the like.

6-3. Processing Operation Next, a processing operation for realizing a recording operation in the case of performing recording on the disc in packet units shown in FIG. 8 will be described with reference to a flowchart of FIG.
This figure mainly shows a process for packetizing audio and image data obtained by, for example, recording by a user. The processing operation shown in this figure is mainly performed by the data processing / system control circuit 3 based on the overall operation control by the video controller 38.
1 controls the components in the video signal processing unit 3 and the driver controller 46 controls the components in the media drive unit 4. Further, on the premise that the signal processing operation in each functional circuit unit is executed as described with reference to FIGS. 4 and 5, detailed description will be omitted here, and only characteristic operations will be supplementarily described. It shall be. Also, the packet to be formed here follows the description shown in FIG.

For example, in this case, in the video camera, the video signal processing unit 3 performs the recording operation or the input of the moving image data (including the audio data) via the external interface 8. As described above, the data of the input moving image is M
A compression process using VBR (variable data rate) is performed according to the PEG2 format.
The compression process is performed according to the RAC2 format. Then, the compressed image data and compressed audio data thus compressed are sequentially written into the buffer memory 32 at required timings. If the data input via the external interface 8 has already been subjected to the compression processing in accordance with the MPEG2 format and ATRAC2 format, the compression processing in the video signal processing unit 3 may be omitted.

[0108] Under the above-described operation state, the processing in FIG. 11 is as follows. First, in step S101, the moving image and the audio data subjected to the compression processing are converted into data to be packetized in the subsequent processing. Is written to. Then, in the subsequent step S102, the storage state of the compressed moving image data and the compressed audio data stored in the buffer memory 32 is monitored.

In the following step S103, as the monitoring of the accumulation state of the compressed moving image data and the compressed audio data, the process stands by until the data accumulation operation for the compressed moving image data and the compressed audio data is executed for 2.03 seconds.
That is, the storage capacity of the compressed moving image data and the compressed audio data in the buffer memory 32 is 10 Mbit / (4.8 Mbit + 0.115 Mbi described above).
t) ≒ 2.03 (second) Even if the data rate of the compressed moving image data is the maximum, even if the data rate of the compressed moving image data and the compressed audio data written so far is 10 Mbit,
It is monitored that a state in which the packet capacity falls within the range described above and the packet capacity is obtained to the extent that the packet capacity can be used almost effectively. If a positive result is obtained in step S103, the process proceeds to step S104.

At step S104, the buffer memory 3
2 to monitor the data size of the compressed moving image data currently stored in the storage unit 2, and the process proceeds to step S105. Step S105
In the above, for example, the data rate of the compressed moving image data currently written in the buffer memory 32 and the type and number of screen data for forming a GOP stored in the buffer memory 32 are used as a judgment material. On the other hand, if the writing of the compressed moving image data is continued more than the accumulated amount of the compressed moving image data in the buffer memory 32, the process waits until it is determined that the compressed moving image data exceeds 9.7 Mbit. That is, the buffer memory 3 for the compressed moving image data
2 is monitored so as not to exceed the capacity (9.7 Mbit) of the image data storage area in the packet. If a positive result is obtained in step S105, for example, the system controller proceeds to step S106, and instructs, for example, the MPEG2 signal processing circuit 33 to perform GOP completion processing. That is, the MPEG2 signal processing circuit 33 performs a necessary completion process for forming one GOP by a plurality of pieces of screen data as moving image data stored in the buffer memory 32 so far. The control is performed for this.

In the following step S107, a process for packetizing is first executed under the control of the data processing / system control circuit 31, for example. That is, the moving image and the audio data accumulated so far in the buffer memory 32 are stored in the audio data storage area and the image data storage area of the packet having the structure shown in FIG. 8, respectively. In the case where there is a voice non-storage area and an image data storage area, dummy data is stored in these areas. Then, the packet formed as described above is read from the buffer memory 32 and transmitted to the media drive unit 4. However, in this example, after the packets are formed in the buffer memory 32, for example, the divided packets Pa and Pb having a required data structure are formed so that the recording method described with reference to FIGS.
The data processing is executed so as to obtain .times..times..times..times..times..times..times..times..times..times..times..times..tim- es.

In the following step S108, the packet data transmitted to the media drive unit 4 in the above step S107 (divided packets Pa and Pb)
Is written to the disk 51. At this time, the driver controller 46 transmits the divided packets Pa and Pb forming one packet to the track Tr as shown in FIGS. 9 and 10, for example.
The access control to the disc is executed so as to be recorded for A, Tr and B.

As described above, one packet of the disk 5
After the recording for No. 1 is completed, by returning to the processing of step S102, packets are sequentially formed according to a time-sequential sequence and recorded on the disk.

7. Reproduction of packet 7-1. Example of Packet Management Mode In this example, as described above, recording of moving image / audio data such as recording information is performed using a packet as a minimum recording unit, and management of data thus recorded is performed. This is also performed on a packet-by-packet basis. Thereby, even when special reproduction such as cue / review reproduction of data or random access is required for editing processing such as changing the reproduction order,
Processing on a packet basis becomes possible.

FIG. 12 shows an example of the data contents of the U-TOC for enabling the recording / reproducing operation to be managed in packet units. As can be understood from the above description, the moving image / audio data such as the recording data in this example is recorded on the disk 51 by a sequence of packets. Packets (# 1) to Packet (#n) from the packet recorded at the top to the packet recorded at the last
It is made to attach a number like this. Here, in order to assign a number to a packet recorded on the disk 51, for example, a continuous packet number may be assigned regardless of a file delimiter. Beyond this, it may be possible to easily perform data management in packet units even when performing some kind of editing processing.

As management information associated with each packet of each number, for example, as shown in the figure, a start address (Start Address),
s), additional information, link information and the like are set, and an area for storing such management information is provided.

The start address is the information of the address of the recording start position on the disk on which the packet with the number is recorded, and the end address is the information on the disk on which the packet with the number is recorded. Is the address information of the recording end position. Further, the additional information is information of required additional contents such as the data rate of the compressed moving image data (GOP) stored in the packet corresponding to the number. Although detailed description is omitted here, additional information based on a plurality of types of required definition contents is stored in a storage area in a predetermined structure in the additional information. The link information is information for specifying the reproduction order in packet units.
For example, the number of the packet to be reproduced next to the packet with the number is shown.

When recording data, such management information is created by the data processing system control circuit 31, for example, in accordance with the progress of packet recording, and is held in the buffer memory 32. Then, for example, after the operation of recording the data of one file on the disk 51 is completed, at a predetermined timing and timing, writing is performed as U-TOC data for packet management in a predetermined area in the management area of the disk 51. To be done.

7-2. Editing process example in packet unit In this example, when editing such as changing the playback order of a file or the like is performed after recording data, the file is managed in the playback order according to the editing result. , U
-The data content of the TOC is rewritten, and the data recorded as user data in the data area is not directly rewritten. The same can be said for the U-TOC for packet management.

Therefore, the UT for packet management described above is used.
As an example of the reproduction operation based on the OC, a case where an editing process for changing the reproduction order is performed will be described with reference to FIG. FIG.
FIG. 12A shows the packet management U-code shown in FIG.
Only the relationship between the packet number and the link information is extracted and shown from the data structure of the TOC. Here, FIG.
As shown in (a), for the sake of convenience, it is assumed that three packets, packets (# 1), (# 2), and (# 3), are recorded, and the link information given to these packets is Are Packet (# 1), (#
2) and (# 3) are <Packet2> and <Packet2, respectively.
Packet3>, <---->. Here, for the above <Packet2> and <Packet3>, actually, Packet (# 2),
This means that the data value indicating the packet number of (# 3) is stored. For <---->, a predetermined data value indicating that there is no packet to be linked thereafter is stored. According to this link information, Packet
(# 1) → Packet (# 2) → Packet (#
This means that the reproduction is specified in the order of 3). Therefore, when actually reproducing based on this link information, as shown in FIG.
The device operates so that the reproduction is performed in the order of 1) → Packet (# 2) → Packet (# 3).

At the time of reproduction, the U-TOC data recorded in the management area is first read, for example, when the disc 51 is loaded, and the read U-TOC is read.
The data is stored in, for example, the buffer memory 42 of the media drive unit 4 (or the buffer memory 3 of the video signal processing unit 3).
Writing is performed for 2), and is held here. Then, when reproducing the data area, by referring to the data content stored in the buffer memory,
So that the playback operation according to the data content is executed,
Driver controller 46, video controller 38,
In addition, the data processing system control unit 31 and the like execute required control. Based on such an operation, the packet shown in FIG. 13B can be reproduced according to the data content of the U-TOC shown in FIG. Specifically, for example, the driver controller 46 refers to the U-TOC link information shown in FIG.
The data of the number specified by the link information is sequentially accessed to read the data, and the data is transmitted to the video signal processing unit 3. Thereafter, by the control operation of the data processing / system control, the separated extraction processing and the decompression processing of the compressed voice data and the compressed image data are performed on the transmitted packet,
Finally, the image is output from the display unit 6A and the speaker 205 as a reproduced image and a sound whose reproduction time axes are matched.

Here, for example, an editing operation by the user causes the packet to be reproduced in the order of packet (# 1) →
It is assumed that a change is made so that Packet (# 3) → Packet (# 2). In this case, first, as the data content of the U-TOC for packet management, the area of the link information is rewritten from the content shown in FIG. 13A to the content shown in FIG. That is, Packet (# 1),
<Packet 3>, <−−−−>, <−−−−>,
<Packet2> will be stored. In such a rewriting process, for example, the U-TOC temporarily stored in the buffer memory is rewritten,
Thereafter, at a predetermined opportunity, the contents of the management area of the disk 51 are rewritten so as to be the same as the contents of the buffer memory. Then, when the Packets (# 1), (# 2), and (# 3) are reproduced after the editing process, the Packets are reproduced according to the above-described reproducing operation.
t (# 1) → Packet (# 3) → Packet (#
The data is read out by accessing the disk in the order of 2), and the reproducing process is sequentially performed on the data. As a result, as shown in FIG.
t (# 1) → Packet (# 3) → Packet (#
Data is reproduced in the order of 2).

As described above, in this example, the editing process is performed in packet units, and the reproducing operation is performed according to the editing result. In such a method, for example, the minimum editing unit of the moving image data is used. Even if the GOP (here, GOP) has a variable length, it is possible to perform a reproducing operation according to the editing result based on a fixed-length packet unit without considering this.

8. Recording and playback of post-record files For example, as a general editing operation for video sources,
What is called so-called after-recording (after-recording) is performed, in which audio is additionally recorded later so as to correspond to the reproduction time axis of the video source. For example, in the video camera of this example, if the user can perform a post-recording operation on the recording data recorded on the disk 51 by, for example, recording, the recording contents can be further enhanced. Can be done. Therefore, hereafter, on the premise of the configuration described above, a configuration for realizing the after-recording function in the video camera of this example will be considered.

When recording post-record audio data on a disk, one reason is that, in the packet data of the present example shown in FIG. 8, the post-record audio data corresponding to the reproduction time of the moving image data of the packet is included. It is conceivable to provide an after-recording data area for storing audio data. In this case, for example, at the time of recording of the first packet by recording or the like, the post-recording data area in the packet is set to an empty area, and the post-recording is performed at a certain opportunity after the end of data recording by this recording. At times, it is conceivable to write data in which the after-recording sound is compression-coded by ATRAC2 in the after-recording data area.

Although such a technique is possible, in this case, since the post-recording data area is in a packet recorded in the past, the recording position is not appropriate due to, for example, an external impact or vibration applied during recording. When a recording error that deviates from the position occurs, the possibility of erasing data recorded in the past becomes very high. As described above in the description of the disk recording method, it is preferable that such data destruction due to a recording error be avoided as much as possible. Therefore, in this respect, a method of storing post-record data in a packet is not practical. .

Therefore, as another method, a recording file different from a file recorded by a sequence of packets (since such data is composed of moving image and audio data as described above, hereinafter also referred to as an "image / audio file"). It is conceivable to record post-record data on a disc as a file to be recorded at the position. In other words, the dubbing data corresponding to a file such as a certain recorded video is recorded as one time-series data file independently of the file such as the recorded video. In this case, even if the above-described recording error occurs during the recording of the post-record data, the possibility of destroying the data of the image / audio file recorded in the past is extremely low. Therefore,
In this example, in consideration of protection of past recording data, a configuration is adopted in which an after-recording file is recorded independently of an image / audio file.

However, in the case of this example, the video / audio data in the packet is of variable length, and the reproduction output time differs for each packet. For this reason, for example, when a configuration is adopted in which only the reproduction start time of the image / audio file and the after-recording file of the image / audio file are synchronized and output during reproduction, for example, a cue (fast forward /) When special playback such as review (rewind) is performed, it is not possible at this point to match the playback time axis between the image / audio file and the after-recording file. During normal reproduction, it is no longer possible to perform post-record reproduction at an appropriate timing.

In order to solve the above problem, in the case of the present example, for example, management information for associating the reproduction time of each packet forming the image / audio file with the reproduction time of the post-record file. May be provided. By referring to this management information, even if cue / review reproduction is performed, the correspondence between the currently reproduced image / audio file (packet) and the data position in the post-record file can be obtained.

The recording of the management information for reproducing the post-record file as described above includes, for example,
It is conceivable that the management information is recorded in the management area 1 in this example. However, in this example, the management information for reproducing the post-record file is taken into consideration, for example, in order to avoid complicating the management information recorded in the management area. Consider a configuration in which an additional post-recording file is provided.

Based on the above considerations, in this example, the recording of a post-record file,
And perform post-recording reproduction. Here, the “after-recording reproduction” refers to reproducing the after-recording file in synchronization with the image / audio file.

Here, the recording operation of the after-recording file in the video camera of this embodiment will be described. For example, the user operates the search keys 308 and 309 to select and specify the file in which the after-recording sound is to be recorded, and
Is operated to set the post-recording mode.

In the after-recording mode, the search key 30 is read from the disc 51 in the video camera.
The file designated by the operations of 8, 309 is read and transmitted to the video signal processing unit 3. At this time, in the video signal processing system including the MPEG2 video signal processing circuit 33 in the video signal processing unit 3, the transmitted image data (here, the compressed moving image moving image data stored in the image data storage area of the packet) is transmitted. Is reproduced, and the image is displayed on the display unit 6A. Also,
At the same time, the audio compression encoder / decoder circuit 38 in the video signal processing unit 3 is controlled by the video controller so as to operate as an encoder suitable for recording.

[0134] Under the operating state of such a device, for example, the user is made to record audio dubbed by the microphone 202. The audio dubbing sound picked up by the microphone 202 is subjected to compression processing in the audio compression encoder / decoder circuit 38 and stored in the buffer memory 32.

Then, the reproduction output of the moving image data and
During the period in which the dubbing audio data is stored in the buffer memory 32, the data processing system control circuit 31, for example, constantly monitors the data content of the moving image data to be reproduced and output. When a packet delimiter position is detected as data, a time-series data position of the after-recording audio data corresponding to the packet delimiter position (the beginning of each packet) in terms of reproduction time is identified. “Recording management information” indicating the correspondence between the data position information and the corresponding packet is sequentially created. Then, this "post-record management information" is also stored in the buffer memory 32.

Then, for example, in the state where the operation in the after-recording mode is being performed as described above, when the user operates the after-recording key 310 again or the reproduction of the specified file is completed, for example, The video camera shifts to an operation for ending the post-recording mode. At this time, first, the reproduction operation of the file on the disk 51 is stopped, and the encoding operation of the audio compression encoder / decoder circuit 38 is also stopped.

At this time, in the buffer memory 32 of the video signal processing unit 3, the data of the post-recorded audio and the post-recording management information which have been recorded so far are recorded. On the other hand, by creating a header having a structure including at least the post-record management information and adding the header to the beginning, this is created as a post-record file. Then, the buffer memory 32
, And an operation for recording the data on the disk 51 via the media drive unit 4 is performed.

At this time, it is assumed that the data of the after-recording file is written to the after-recording area on the disc 51 as shown in FIG. By providing the after-recording area as an area different from the data area in which the image / audio file is recorded, destruction of the data of the image / audio file as main data due to the recording error described above can be avoided as much as possible.

For example, after the recording of the post-record file is completed, as the management information (U-TOC) relating to the file recorded on the disk 51, an image / audio file in which the post-record audio is recorded in the past post-record mode is used. Is rewritten so that data indicating that there is a post-record file and information indicating the recording position (address) on the disc of the post-record file corresponding to the image / audio file are provided.

Here, the data structure of the post-record file recorded on the disc as described above is, for example, as shown in FIG. As shown in this figure,
One post-record file is formed by a post-record audio data storage area in which the post-record audio data is stored following the header AR1. The post-record file is
This becomes time-series data having a variable length according to the reproduction time of the corresponding image / audio file.

As the information stored in the header AR1, “post-record management information” indicating the correspondence between each packet forming the video / audio file and the data position on the post-record audio data is, for example, as shown in FIG. It becomes what is shown in. Here, for simplicity of description, an image / audio file to which a certain post-record file is associated is defined as a packet number as Packet (# 1), (# 2),
Assuming that the packet is formed by the three packets (# 3), the "post-record management information" is as shown in FIG.
Packet (# 1), (# 2), (# 3)
The address on the post-recording audio data area corresponding to the reproduction start time of is shown. In this figure, the packet number P
For address (# 1), (# 2), and (# 3), address ADR [A] and address ADR, respectively.
[B] and address ADR [C]. In this case, regarding the address ADR [A], actually,
An address indicating the head position of the post-record audio data area is stored.

The basic operation of post-recording reproduction based on such a post-record file is shown in FIG.
It is shown by the relationship of (b). At the time of post-recording reproduction, first, various U-TOC data in the management area of the disk 51 is read and stored in the buffer memory 42 (or the buffer memory 32).
The reading of the image / audio file from the data area and the after-recording file corresponding to the image / audio file are performed. In the case where the optical head 53 adopts one configuration as in this example, the image / audio file and the post-record file recorded in physically different areas cannot be read from the disk 51 at the same time. First read all post-record files,
The video and audio files are stored in the buffer memory 32 and thereafter read from the data area in packet units. Even if all the post-record files are read out first, since the audio data is compressed audio data, the data capacity is not so large, so that the time required for reading out can be shortened accordingly.

Here, as an after-recording reproduction operation, it is assumed that the after-recording file shown in FIG. 14A is first read from the disk 51 and stored in the buffer memory 32. At this point, for example, the data processing / system control circuit 31 can refer to the header content of the post-record file.

Thereafter, as an image / audio file corresponding to the post-recording file shown in FIG.
As shown in FIG. 4 (b), Pack
The packets are read out and reproduced in the order of et (# 1), (# 2), (# 3). At this time, the data processing / system control circuit 31 starts reproducing and outputting the packet (# 1) to the display unit 6A as shown in FIGS. Address AD on the after-recording audio data area of the after-recording file so that the reproduced voice is started to be output from the speaker 205 in accordance with the timing of the reproduction.
Control for executing signal processing on data read from R [A] is performed.

Thereafter, similarly, the packet (# 2)
→ The address AD of the post-record audio data area is synchronized so as to be synchronized with the playback / output timing of the packet (# 3).
Following the reproduction output of the data read from R [B], the reproduction output of the data read from the address ADR [C] is executed. In this example, reproduction of the after-recording audio synchronized with the display image is realized based on the after-recording management information stored in the header as described above.

However, as shown in FIGS. 14A and 14B, when the data arrangement along the reproduction time axis of the post-record audio data area and the reproduction order of the packets match, for example, , For normal playback only, Pack
Data playback is performed so that the playback output start timing of et (# 1) matches the playback output start timing from the address ADR [A] on the after-recording audio data area,
Thereafter, the reproduction process is performed according to the normal data processing clock, and the packet (# 2), (#
It is not necessary to control the playback output timing of the post-record audio data area from the address ADR [B] [C] so as to synchronize with the playback output timing of 3).

At the time of post-recording reproduction, the original audio data stored in the packet as an image / audio file is also reproduced, and the post-recording audio is synthesized with the original reproduced audio to be reproduced and output. Is, of course, possible. To realize this, for example, the original audio data extracted from the packet and subjected to decompression processing, and the post-recording audio data of the reproduction time corresponding to the original audio data are read out from the post-recording audio data area and expanded. Then, the audio data may be mixed by, for example, digital signal processing, and output from the D / A converter 64 to the speaker 65.

9. Cue / review reproduction (during dubbing reproduction) Next, cue / review reproduction during dubbing reproduction in this example will be described with reference to the flowchart in FIG. The cue / review reproduction here is a special reproduction operation in which reproduction of a so-called fast-forward (cue) / rewind (review) state is obtained when moving image data is reproduced. is there. This processing operation is also based on the overall operation control by the video controller 38, and controls each unit in the video signal processing unit 3 by the data processing / system control circuit 31, and controls each unit in the media drive unit 4 by the driver controller 46. Is executed.

In the process shown in FIG. 15, first, in step S201, the cue review reproduction by the user is performed under the condition that the normal post-record reproduction operation described with reference to FIGS. Waiting for an operation to be performed. Then, for example, when it is determined that the review operation on the search key 308 described in FIG. 6 or the cue operation on the search key 309 has been performed, the process proceeds to step S201.

In step S202, first, prior to cue / review reproduction, control for stopping reproduction output of the post-record file is executed. Thus, the reading of the after-recording audio data held in the buffer memory 32 by the data processing / system control circuit 31 is stopped.

In the following step S203, for example, the operation mode is changed so that the operation of each functional circuit unit in the video signal processing circuit 3 corresponds to cue / review reproduction. The operation is performed so that the reproduction is performed and, if the review operation is performed, the review reproduction is performed.

In this example, the cue / review reproduction is also performed based on data reading and reproduction signal processing in packet units. The basic operation at this time is as follows.
Description will be made again with reference to FIG. When cue / review reproduction is performed, the data processing / system control circuit 31
Reads the compressed audio data stored in the audio data storage area from the data in packet units shown in FIG. 8, for example, and then is located at the top of the GOP stored in the image data storage area. Reading is performed only for the I picture. At this time, as described above, the audio data storage area is positioned at the top of the packet, and the still picture data to be read is defined as the I-picture positioned at the top of the GOP. The subsequent I-picture reading process is simplified so that signal processing is performed more quickly.

For the audio data extracted from the packet, under the control of the data processing / system control circuit 31, the output mode of the reproduced audio suitable for the cue / review reproduction (for example, the audio corresponding to the cue / review reproduction speed) The signal processing is performed so as to obtain high-speed output or to reproduce audio data in which data is intermittently thinned out at a certain timing.
5 is output.

The I picture taken out from the image data storage area of the packet is supplied to the MPEG2 video signal processing circuit 3 where it is subjected to decompression processing. Signal processing is performed so that display output as review reproduction is performed and output to the display unit 6A. And such data processing in packet units is
By being sequentially executed according to the packet reproduction order, cue / review reproduction of the image / audio data is realized. As a reproduced image by cue / review reproduction based on such processing, a state is obtained in which a still image based on an I picture is displayed in such a manner as to be changed at high speed in a frame-by-frame manner. In step S203, the operation of the video signal processing unit 3 as described above is started.

[0155] When playing back the cue / review,
It is not always necessary to sequentially decode packets one by one according to the packet reproduction order.
In particular, when high-speed cue / review reproduction is required, random access is performed while skipping data for a certain number of packets along the packet reproduction order,
It is also possible to execute the reproduction process for the data in the packet as described above.

After the cue / review reproduction is started by the processing in step S203, the process proceeds to step S204. For example, the data processing / system control circuit 31 determines the number of packets (n ) Is executed. The number of packets (n) counted here is recorded on the disk irrespective of whether packets are sequentially decoded one by one according to the packet reproduction order or data is skipped by a certain number of packets. This is based on the elapsed number of packets in the assumed sequence. The processing in step S204 is executed until it is determined in step S205 that the cue / review operation is canceled.

If it is determined in step S205 that the cue / review operation has been canceled, in step S206, the cue / review reproduction operation started by the previous step S203 is terminated.
The operation mode of each functional circuit unit in the video signal processing unit 3 is changed so that a normal moving image file (packet) is reproduced. The counting of the number of elapsed packets in step S204 is also stopped at this time, and the number of packets (n), which is the last count value, is held by the data processing / system control circuit 31, for example.

In the following step S207, based on the number of packets (n), an address on the post-record audio data area in the post-record file moved corresponding to n + 1 packets in the queue / review direction is read. Set the pointer. That is, by referring to the header of the post-record file held in the buffer memory 32 (see FIG. 14), the packet number obtained by adding n + 1 to the packet number corresponding to the start of cue / review reproduction is identified. A read pointer is set for an address in the post-record audio data area associated with the packet number. Here, the packet of the packet number obtained by adding (n + 1) to the packet number corresponding to the start of the cue / review reproduction is defined as when the cue / review reproduction ends and the normal reproduction operation starts. First, it corresponds to a packet that is reproduced properly from the beginning.

In the next step S208, while the normal reproduction of the video / audio file (packet) is being performed in the previous step S206, the delimiter (head position) of the packet to be obtained first is detected. It is made to wait for it. This detection process is realized by the data processing / system control circuit 31 monitoring the data of the image / audio file transmitted from the media drive unit 4, for example.

If a packet break (head position) is detected in step S208, the reproduction start time of this packet corresponds to the reproduction start time of the post-record audio data for which the read pointer has been set in step S207. Will be. Therefore, the data processing / system control circuit 31 performs post-recording processing in the next step S209 so as to synchronize with the reproduction time of the packet including the head position detected in the above-mentioned step S208 as the control processing for resuming reproduction of the post-recording track. In order to reproduce and output the voice, reading of the post-record audio data is started from the data position where the read pointer is set, and after performing necessary signal processing, the data is output to the speaker 205.

As described above, in this example, during the cue / review reproduction operation, during the cue / review reproduction execution period, the reproduction sound of the post-record sound is muted (stopped) as the cue / review reproduction operation during post-record reproduction. Even if it is done,
At the time point when the reproduction is returned from the cue / review reproduction to the normal reproduction, the post-recording sound can be reproduced and output almost immediately in synchronization with the normal reproduction image. This is because, as described above, after-record management information indicating the correspondence between the packet and the address on the after-record audio data based on the reproduction time is provided.

It should be noted that the present invention is not limited to the configuration shown in the above embodiment, but various changes can be made in accordance with actual use conditions and the like. For example, a U-TOC (management The structure of (information) and the management form based on this management information can be variously conceived. In addition, the data structure of the packet is also conceivable, and an area for storing some other type of data may be provided. In some cases, the audio data storage area may store audio data that is not subjected to audio compression processing. Furthermore,
Various control processes for realizing cue / review reproduction other than those shown in FIG. 15 are also conceivable. In this case, the process of associating the packet with the post-record data is also performed during the cue / review reproduction. Various uses are possible other than using the value obtained by counting the number of packets.

In the video camera of the present embodiment, a disk recording / reproducing device based on MD-DATA2 is used as a video recording / reproducing portion. However, the video recording / reproducing portion has a configuration other than that of the present embodiment. Alternatively, the recording / reproducing apparatus may be a recording / reproducing apparatus compatible with other types of disc-shaped recording media. Further, in the present embodiment, the description has been made on the assumption that the MPEG2 system is employed for compressing the moving image data. However, for example, a system capable of compressing and encoding other moving image data may be employed. Also, the compression method for still image data and audio data need not be particularly limited to those exemplified as the present embodiment (JPEG, ATRAC2, etc.).

[0164]

As can be seen from the above description, the present invention has the following effects. First,
According to the first aspect of the present invention, as a disc-shaped recording medium, two tracks sharing a physical wobble in which address information is encoded are spirally formed to improve the recording density, and then perform recording. By recording data on different tracks for each recording data unit forming data, data protection during data recording can be achieved as much as possible. According to the second aspect of the present invention, if the recording data unit is formed based on a fixed-length data unit (packet) formed by storing data of a predetermined type, for example,
For example, data processing at the time of reproduction can be simplified as compared with the case where the recording data unit has a variable length. In this case, as described in the third aspect of the present invention, the data protection effect described above can be further enhanced by recording one packet on a different track for each recording data unit. .

Further, according to the disk-shaped recording medium of the present invention, at least compressed image data subjected to compression processing at a variable rate is formed for a data unit (packet) to be managed having a fixed length. By providing an area for storing one or more variable-length compressed data units (GOP in the case of MPEG2), variable-length compressed data, which is difficult to perform in actual access control and reproduction management, is regarded as a fixed-length data unit. As a reproduction operation, it is possible to provide a recording medium capable of realizing, by a simple process, a special reproduction, which requires random access to a disc, and an edit reproduction process. A recording medium capable of recording and reproducing audio data together with compressed moving image data by providing an audio data storage area in which audio data is stored for the data to be managed, as described in claim 5. Is obtained. Further, as described in claim 6, data formed by a sequence of data units to be managed is used as main data, and auxiliary audio data (after-record file) corresponding to a moving image of the main data is used as sub-data. Recorded, and this auxiliary audio data is
By adopting a form in which the data position to be reproduced corresponding to each of the variable-length compressed data units is managed so as to be specified, audio data is recorded later for a once-recorded moving image, It is possible to use a recording medium that can support what is called after-recording, and the use value is enhanced. Based on the premise of the invention described in claim 6, as described in claim 7, the area in which the main data is recorded and the recording area in which the sub data is recorded are set as physically different recording areas. Therefore, for example, even when recording additional audio dubbing audio data as sub-data at a certain opportunity after recording the main data,
For example, a situation in which the main data recorded in the past is lost or destroyed due to a recording error caused by a shock or the like is avoided as much as possible, and the reliability of data protection is also improved here. .

Then, the data is stored in a variable-length compressed data unit (eg, GOP in the MPEG2 format) in a management target data unit (packet) having a fixed length, and recorded or recorded for each packet. If the recording of the management information for managing the reproduction operation and the recording of the data by the sequence of the packets are performed, the reproduction management of the variable-length moving image data as described in claim 4 is simplified. This makes it possible to create a disk-shaped recording medium that can be used in the above-mentioned manner.

According to the reproducing apparatus of the ninth aspect, when reproducing from a disk-shaped recording medium, a data unit to be managed is determined based on management information for managing recording and reproduction of a packet. , The data stored in the management target data unit is reproduced. That is, even in the case where variable-length image data is reproduced, the reproduction processing can be performed by simple processing by treating this as fixed-length packet units. Therefore, as the management information, management information that specifies the reproduction order for the data units to be managed is defined, and each of the data units to be managed is defined in accordance with the reproduction order specified by the management information. What is necessary is just to execute the process of reproducing the data. For this reason, for example, when it becomes necessary to change the playback order of the data to be managed by editing processing such as changing the playback time of an image, the management information may be updated according to the editing result, and the editing and playback may be performed. By performing the reproducing operation according to the tenth aspect based on the updated management information, a heavy process such as directly editing the original image data is not particularly required, so that it can be easily realized.

Further, according to the eleventh aspect of the present invention, while the compressed moving image data recorded on the disk is reproduced and output, it is synchronized with the compressed moving image data so as to be independent of the compressed moving image data. Audio data (post-record audio data) can be reproduced and output. That is, it is possible to perform post-recording reproduction. Moreover, in the post-recording reproduction according to the present invention, a variable-length compressed data unit (for example, MPEG2
Is managed so that the data position where the post-record audio data is to be reproduced is specified for each packet in which the GOP is stored. Can be played back from the data position of the post-record audio data to be played. For example, even if the image is played from the middle of the file,
After-recording audio can be played back synchronously. In this case as well, the variable-length compressed data unit is handled by the fixed-length packet, so that the processing for post-recording reproduction can be reduced.

At the time of post-recording reproduction, the cue /
When the review playback operation is performed, as described in claim 11, the management target data unit in which the moving image data to be played back as the normal playback after the cue / review playback is stored is determined. At the same time, based on the reproduction management information, the data position of the after-recording audio data corresponding thereto is specified as the reproduction start position, and when the normal reproduction of the data unit to be managed is started, the normal reproduction is started, and By performing post-recording audio data reproduction from the reproduction start position, it is possible to quickly return to post-recording reproduction after cue / review reproduction ends. If there is no particular playback management information indicating the correspondence between the data unit of the data to be managed and the data position of the after-recording audio data as in the present invention, it is assumed that the normal playback is resumed after the cue / review playback. However, it is very difficult to restore the after-recording reproduction since the reproduction time between the display image and the after-recording audio data has not been established yet.

As described above, according to the present invention, it is possible to cope with a reproducing operation for variable-length image data, in particular, a special reproduction or an edit reproduction that requires random access or the like by a simple control process. As a result, the processing load on the reproduction signal processing system is remarkably reduced as a whole, and the effect that the configuration can be simplified and the size can be reduced can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a track structure of a disc corresponding to a video camera according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a track portion of a disc corresponding to the video camera of the embodiment in an enlarged manner.

FIG. 3 is an explanatory diagram showing specifications of a disc corresponding to the video camera of the embodiment.

FIG. 4 is a block diagram of an internal configuration of the video camera according to the embodiment.

FIG. 5 is a block diagram of an internal configuration of a media drive unit of the video camera according to the embodiment.

FIG. 6 is a side view, a plan view, and the like of the video camera according to the embodiment;
And a rear view.

FIG. 7 is a conceptual diagram showing an example of a disk structure corresponding to the present embodiment.

FIG. 8 is an explanatory diagram showing a packet structure in the present embodiment.

FIG. 9 is an explanatory diagram showing an example of a recording method for recording a packet on a disk.

FIG. 10 is a conceptual diagram showing tracks on a disc on which data is recorded according to the recording method shown in FIG.

FIG. 11 is a flowchart showing packetization processing at the time of recording.

FIG. 12 is an explanatory diagram showing an example of data contents of a U-TOC for packet management.

FIG. 13 is an explanatory diagram showing a data reproducing operation based on a U-TOC for packet management.

FIG. 14 is an explanatory diagram showing the contents of management information in the header of the post-record file and the post-record reproduction operation based on the management information.

FIG. 15 is a flowchart showing a processing operation relating to a cue / review reproduction operation during post-record reproduction.

[Explanation of symbols]

1 lens block, 2 camera block, 3 video signal processing section, 4 media drive section, 5 deck section,
6 display / image / audio input / output unit, 6A display unit, 7 operation unit, 8 external interface, 9 power supply block,
Reference Signs List 11 optical system, 12 motor unit, 22 sample hold / AGC circuit, 23 A / D converter, 24 timing generator, 25 camera controller, 31
Data processing / system control circuit, 32 buffer memory, 33 video signal processing circuit, 34 memory, 35 motion detection circuit, 36 memory, 37 audio compression encoder / decoder, 38 video controller,
41 MD-DATA2 encoder / decoder, 42
Buffer memory, 43 binarization circuit, 44 RF signal processing circuit, 45 servo circuit, 46 driver controller, 51 disk, 52 spindle motor, 53
Optical head, 54 magnetic head, 55 thread motor, 61 video D / A converter, 62 display controller, 63 composite signal processing circuit, 64 A /
D converter, 65 D / A converter, 66 amplifier, 101 RF amplifier, 103 AGC / clamp circuit, 104 equalizer / PLL circuit, 105 Viterbi decoder, 106 RLL (1, 7) demodulation circuit, 107
Matrix amplifier, 108 ADIP bandpass filter, 109 A / B track detection circuit, 110 ADI
P decoder, 111 CLV processor, 112 servo processor, 113 servo driver, 114 data bus, 115 scramble / EDC encode circuit, 116 ECC processing circuit, 117 descramble / EDC decode circuit, 118 RLL (1, 7) modulation circuit, 119 Magnetic head drive circuit, 120 laser driver, 121 transfer clock generation circuit, 201 camera lens, 202 microphone, 203 disk slot, 204 viewfinder, 205 speaker, 3
00 main dial, 301 release key, 304
Zoom key, 305 Eject key, 306 Play key, 307 Stop key, 308, 309 Search key,
310 post-recording key, Ld land, NWG non-wobbled groove, WG wobbled groove, Tr.
A, Tr ・ B Truck

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code Fig11B 27/10 A

Claims (12)

[Claims] As a track on which data is recorded, two tracks sharing a physical wobble in which address information is encoded are formed in a spiral shape, and data to be recorded on the track is formed in a predetermined format. When the recording data unit is based on a defined sequence of recording data units, a certain recording data unit and a recording data unit located next to the certain recording data unit in the sequence are recorded on different tracks from each other. A disk-shaped recording medium characterized by the above-mentioned. 2. The disk-shaped storage medium according to claim 1, wherein the recording data unit is formed based on a fixed-length data unit formed by storing one or more predetermined types of data units. recoding media. 3. The disk-shaped recording medium according to claim 2, wherein the recording data unit is formed by dividing the fixed-length data unit into a predetermined number. 4. A data in a sequence of data units to be managed, which is a data unit of a fixed length, and management information for managing a recording or reproducing operation for each of the data units to be managed, are recorded. In the management target data unit, at least an image data storage area for storing at least one variable length compressed data unit forming compressed moving image data subjected to compression processing at a variable rate is set. Disk-shaped recording medium. 5. In the management target data unit, an audio data storage area for storing compressed audio data that has been subjected to compression processing and that is to be reproduced corresponding to a variable length compressed data unit in the management target data unit is provided. And the variable length compressed data in the same management target data unit which is set as a different area from the image data storage area and is associated with the compressed audio data based on a required purpose. 5. The disk-shaped recording medium according to claim 4, wherein the data positional relationship with the specific screen data is set to be within a predetermined range. 6. The data formed by the sequence of the data unit to be managed is recorded as main data.
Auxiliary audio data to be reproduced and output together with the variable length compressed data unit is recorded as sub data, and the auxiliary audio data is reproduced corresponding to each variable length compressed data unit by reproduction management information. The disk-shaped recording medium according to claim 4, wherein the data position to be managed is specified so as to be specified. 7. The disk-shaped disk according to claim 6, wherein an area in which the main data is recorded and a recording area in which the sub-data is recorded are set as physically different recording areas. recoding media. 8. A variable length compressed data unit acquiring means for acquiring a variable length compressed data unit forming compressed moving image data which has been subjected to a compression process at a variable rate, and as a fixed length data unit for recording / reproducing management. A managed data unit generating means configured to generate a managed data unit storing at least one or more of the variable length compressed data units, and recording or reproducing the disc-shaped recording medium for each of the managed data units A recording apparatus comprising: recording of management information for managing operations; and recording control means capable of recording data in the sequence of the data to be managed. 9. Data is recorded in a sequence of a data unit to be managed, which is a data unit having a fixed length, and management information for managing a recording or reproducing operation for each data unit to be managed. In the management target data unit, reproduction can be performed corresponding to a disk-shaped recording medium in which at least one variable length compressed data unit forming compressed moving image data subjected to compression processing at a variable rate is stored. A playback device for reading out the management target data unit from the disc-shaped recording medium based on the management information, and reproducing and outputting data stored in the read management target data unit. A reproduction apparatus comprising reproduction control means for executing reproduction control. 10. The reproduction control means can execute reproduction control for reproducing and outputting data in each management target data unit in accordance with a reproduction order of the management target data unit specified by the management information. The playback device according to claim 9, wherein 11. A sequence of managed data units in which at least one variable-length compressed data unit forming compressed moving image data subjected to compression processing at a variable rate is stored as a data unit of a fixed length. And auxiliary audio data to be reproduced and output together with the variable-length compressed data unit. The auxiliary audio data is data to be reproduced corresponding to each of the variable-length compressed data units according to reproduction management information. A playback device capable of performing playback corresponding to a disk-shaped recording medium whose position is specified and managed, wherein data is read from the disk-shaped recording medium in management target data units, and at least this Reproduction of an image in a required display mode based on the variable-length compressed data unit extracted from the read management target data unit Image reproduction control means capable of performing, and the data position of the auxiliary audio data to be reproduced and output for each variable-length compressed data unit reproduced and output by the image reproduction control means, in the reproduction management information A data position identification unit that can be identified based on the data position identification unit at a predetermined timing so that the auxiliary sound is reproduced and output in synchronization with a variable length compressed data unit reproduced and output by the image reproduction control unit. And an auxiliary audio reproduction control means for reproducing the auxiliary audio data from the data position specified by the means. 12. The image playback control means can set a normal playback mode and a fast forward or fast reverse playback mode for fast forward or fast reverse playback as an image playback output based on the variable length compressed data unit. And a progress state detecting means for detecting a progress state as a sequence of data units to be managed reproduced according to the fast forward or fast reverse direction under the condition that the fast forward or fast reverse playback mode is set; and Based on the detection result by the progress state detecting means, after the fast forward or fast reverse reproduction mode is released and the mode is shifted to the normal reproduction mode, a specific management target data unit to be reproduced by the image reproduction control means is identified. A management target data unit identifying unit, wherein the data position specifying unit is configured to determine the management target data unit based on the reproduction management information. The data position of the auxiliary audio data to be reproduced corresponding to the management target data unit identified by the data unit identification unit is specified as a reproduction start position, and the auxiliary audio reproduction control unit determines whether the fast forward or fast reverse reproduction mode is set. After being released and shifting to the normal reproduction mode, the reproduction start position is set so that the auxiliary sound is reproduced and output in synchronization with the reproduction output of the management target data unit identified by the management target data unit identification means. The playback device according to claim 11, wherein playback is started from a playback device.