JP3370457B2 - Optical disc, optical disc recording method and recording apparatus, and optical disc reproducing method and reproducing apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image signal recording method and an image signal recording apparatus for encoding and recording an image signal on a disc medium such as an optical disc, and an image signal from the disc medium on which the image signal is encoded and recorded. The present invention relates to an image signal reproducing method, an image signal reproducing apparatus, and an image signal recording disk medium for reproducing the image.

[0002]

2. Description of the Related Art As an encoding technique for compressing a digital image signal advances, the compressed image signal is recorded on an optical disk so that the searchability and the search performance are improved as compared with a tape medium represented by a conventional VTR. It has become possible to realize an optical disc device having excellent operability. Since such an optical disc device is recorded as a digital signal, it is free from deterioration due to dubbing as compared with the case of recording an analog image signal, and it is a non-contact type and excellent in reliability because it is an optical recording / reproducing device.

On the other hand, as an encoding method for compressing the data of the digital image signal as described above, for example, MPEG (Moving Pict), which is being standardized at present, is used.
ure coding Experts Group)
There is a method. FIG. 7 shows a simplified structure of data encoded by an image signal encoding method according to the MPEG method having a layer structure.

In the figure, reference numeral 100 denotes a GOP (Gr) which is a coding unit in which image signals of a plurality of screens are grouped together.
(up of Pictures) and a sequence layer composed of a sequence header designating an image format, 101 is a GOP layer composed of a plurality of screens (pictures), and 102 is composed of a plurality of slices obtained by dividing one screen. Picture layer, 103 is 1
A slice layer composed of a plurality of macro blocks obtained by dividing a slice, 104 is composed of four blocks of a luminance signal (Y), one block of a color difference signal (RY) and one block of a color difference signal (BY). The macroblock layer 105 is a block layer composed of 8 pixels × 8 pixels. And the encoded data is
It is output as a bit stream (serialized serial data) having the above structure.

The sequence layer 100 has a structure as shown in FIG. In the figure, 5a, 5b, 5
c and 5d are GOPs, and 6a, 6b and 6d are sequence headers (SH). This sequence header is provided to specify the image format such as the number of pixels and the number of lines of the image, and can be attached to the head of all GOPs. In the figure, GOP1, GOP2, and GOP4 are GOPs having a sequence header attached to the head thereof, and GOP3 is a GOP having no sequence header attached. Furthermore, GO of each GOP layer
At the beginning of P, data (hereinafter referred to as a time code) representing the time from the start of the sequence (title, program) is provided.

Further, GOP, which is an encoding unit in which image signals of a plurality of screens in the MPEG standard are grouped together,
(Group of Pictures) has a structure as shown in FIG. This figure shows a case where, for example, 10 screens are set to 1 GOP, and an image signal of one GOP is an intra-coded screen 107 (hereinafter abbreviated as I picture) generated without using inter-frame prediction, Inter-frame forward prediction coding screen 108 (hereinafter abbreviated as P-picture) generated by using forward (pre-) directional inter-frame prediction by an I picture or P picture located temporally previous (past), and time Bidirectional predictive coding screen 109 (hereinafter abbreviated as B picture) generated by using bidirectional prediction using I pictures or P pictures located before and after (past and future) as reference screens.
Of each signal. Then, such a screen (picture) of three types is recorded in the disc as a structure in which some of them are combined.

The I picture (plane), P picture (plane), and B picture (plane) that compose the GOP have the following properties. That is, I picture 1
07 is an intra-frame DCT (Discrete Cosi)
Since it is generated by performing a ne Transform (discrete cosine transform), it is possible to reproduce an image without referring to other pictures on this screen alone, but the P picture 108 refers to the screen in the forward direction. Since it is encoded by performing motion compensation, the image can be reproduced only after the I picture 107 is reproduced, and the B picture 109 is a prediction screen from both directions. , Before and after I picture 1
The image can be reproduced only after the 07 or P picture 108 is reproduced.

Therefore, P pictures and B pictures coded with reference to other pictures are closed within one GOP, as shown by arrows in FIG. 9, that is, a reference screen for P pictures and B pictures. If the encoding is performed so as to refer to the screen in the GOP, the image signal of one GOP can be independently decoded and reproduced.

On the other hand, the B picture 109 which is encoded by performing prediction from both directions has the smallest amount of data and has the highest encoding efficiency, but on the other hand, the B picture 109 cannot be reproduced alone, and the I picture 107 is not reproduced. Since the P picture 108 and the P picture 108 are required, the buffer memory amount required for the processing increases if the number of the B pictures 109 increases, and the delay time associated with the encoding and the decoding increases. But,
In storage media such as optical disks,
The encoding method as described above is suitable because an encoding method having a high compression efficiency is desired for long-term recording and the delay time of the image reproduction is not a problem.

Further, when recording a digital image signal on a recording medium such as an optical disc by a data compression encoding method according to the MPEG system, as shown in FIG. 10A, in order to keep the image quality between GOPs constant. , Each GO
A method of recording the P image signal data as a variable data amount, that is, a method of recording each GOP at a variable data rate, and as shown in FIG. 10B, in order to make the recording time of each GOP constant, A method of recording each GOP at a fixed data rate is considered.

The former method is more advantageous than the latter method in that the recording density on the disk can be increased, and the latter method starts the image of one sequence (title, program). This is advantageous over the former method in that it is easy to predict the recording position of the image data in the case of retrieving and reproducing the image signal at a desired time point.

In the former method, the amount of data per GOP is shown, for example, in FIG. 11 (a) ((α) in the figure represents the maximum value of the data rate, and (β) represents the average data rate). As described above, it changes with time according to the nature of the screen that constitutes the GOP. Further, for example, in three types of images (a), (b), and (c), the image quality per GOP (here, the image S / N after decoding) and the data amount are shown in FIG. 11B. ). Therefore, in the former method, 1 GOP of each image is obtained.
The image quality can be kept constant by varying the amount of data per hit.

As a disc reproducing apparatus adopting such an image signal encoding method based on the MPEG system, there is, for example, a video CD (Compact Disc) player. FIG. 12 shows an outline of the track structure in the video CD and the data structure of the user area of one sector in the track. A margin for a predetermined sector is provided before and after each track, and each sector other than that is used as one MPEG data transmission unit (one pack). At the front part of the image data of one pack, time stamp data, which is data indicating the time from the start of the recorded sequence (title, program), is recorded. An image signal encoded by the MPEG system is recorded by a method in which each GOP is recorded as a fixed data amount, that is, each GOP is recorded at a fixed data rate as described above.

Further, in the video CD, the image signal and the audio signal of one sequence (title, program) to be recorded are treated as one data file, and the GOP forming the data file is shown in FIG. As described above, the continuous data is sequentially recorded in continuous sectors on the disc. Further, file management data (not shown) such as file identification data and file start sector address is recorded on the track located at the head of the disc, and access to the file composed of the image signal and the audio signal of the desired title is performed. It is performed based on this file management data.

When reproducing an image signal of a desired sequence (title, program), the start sector address of the data file corresponding to the sequence is specified by the file management data, and the head of the recorded file is recorded. The sectors following the sector address are sequentially accessed to reproduce the image signal. Generally, data on a recording medium such as a disk is physically recorded in a recording unit called a sector, and recording (writing) and reproducing (reading) of data are performed using this sector as an access unit.

Next, when reproducing a GOP in the middle of a certain sequence (title, program), a sector in the middle of consecutive sectors in which the above data file is recorded is first accessed. Become. However, as shown in FIG. 12, the GOP in the pack of each sector is
Since the data is recorded as continuous data,
The GOP data read out first is from the middle of the GOP, and is read out as the other part recorded by being divided into the immediately preceding sector is missing.

Therefore, since the first read GOP lacks the reference picture data of the P picture and the B picture at the time of encoding, only an unnatural image will be reproduced even if it is decoded. Do not play as unnecessary.

Further, when reproducing a GOP in the middle of a sequence (title, program), particularly at a desired time point from the start point of the sequence, first, a fixed data rate of the recorded image signal The sector address in which the target GOP is recorded is predicted based on the above. Next, the sector corresponding to the predicted sector address is accessed, the signal recorded in the sector is read, and the time stamp data is detected from the signal. Then, by comparing the detected time stamp data with the desired time point, the target G
The sector in which the OP is recorded is identified. Further, the GOP is sequentially read from the first GOP recorded in the sector, the time code at the head of the GOP is detected, and when the time code is at a desired time point, that GOP is the target GOP. Identify that there is a GOP
Is decoded to obtain a reproduced image.

[0019]

In a device for reproducing an image signal from the conventional optical disc or the like as described above, GO in the middle of a sequence (title, program)
When P is reproduced, some missing GOPs read first from the first accessed sector become unnatural images even if they are decoded and output, and therefore, they are not reproduced as unnecessary images. There is a delay before the signal is reproduced and displayed.

Further, when the conventional recording method is applied to a re-recordable (additional recording) medium to perform rewriting in GOP units and editing such as joint shooting, the image signal is continuously recorded in the recording area in the sector. It will be recorded and recorded, so rewrite G
When the OP is in the middle of a sector, if the sector is rewritten, the rear part of the GOP before the GOP to be edited is lost, and if the editing point (editing joint) is played back, the GOP can be played back. I can't do that and the image is missing. Even if it is forcibly reproduced, only an unnatural image is reproduced.

Further, the conventional recording method is re-recorded (additional)
When recording is applied to a possible medium, the entire sequence is treated as one file and recorded in consecutive sectors on the disc, and at the time of playback, the start sector, which is the management data of the file, is recorded. Since the position on the disc where the file is recorded can be identified only by the address, it is not possible to record / reproduce in a free sector generated by repeating erasing or recording, and the recording area of the disc cannot be effectively used.

In addition, in the case of reproducing a GOP in the middle of a certain sequence (title, program),
In particular, the GOP at the desired point from the start of the sequence
When reproducing, the sector address of the sector in which the target GOP is recorded is predicted based on the data rate of the image signal, and the time stamp data representing the time recorded in the sector and the desired By identifying the sector in which the target GOP is recorded by comparing the time code at the beginning of the GOP sequentially read from that sector with the desired time. A complicated process such as identifying a GOP must be performed, a sector in which a GOP at a desired time is recorded cannot be immediately specified, and a delay occurs until an image signal is reproduced. Further, when the image signal of each GOP is recorded at a variable data rate, the time from the start of the sequence and the recorded position are not in a proportional relationship, so that the GOP at the desired time is recorded in the sector. Of the sector address becomes complicated, it becomes more difficult to immediately identify the sector in which the GOP is recorded at the desired time point, and further delay occurs until the image signal is reproduced.

The present invention has been made to solve the above problems, and a first object of the present invention is to provide the above GOP in the middle of the entire image signal such as the above sequence (title, program). Image signal recording method, image signal recording apparatus, image signal reproducing method, image signal reproducing apparatus, and image capable of shortening the time required to reproduce an image signal and output an image when reproducing a coding unit A signal recording disk medium is obtained.

A second object is an image signal recording method in which rewriting in a coding unit, editing such as joint shooting can be easily performed, and even if an editing point is reproduced, a reproduced image can be reproduced without loss. And an image signal recording device, an image signal reproducing method, an image signal reproducing device, and an image signal recording disk medium.

A third object is an image signal recording method and an image signal recording apparatus, and an image signal reproducing method and an image signal reproducing apparatus, which are capable of recording and reproducing by effectively utilizing even empty sectors dispersed on a disk medium. An image signal recording disk medium is obtained.

A fourth object is to reproduce a coding unit such as the GOP in the middle of the entire image signal such as the sequence (title, program),
In particular, when reproducing from a coding unit at a desired time point from the start point of the sequence, the position where the coding unit at the desired time point is recorded can be easily and immediately specified, and the image signal An image signal recording method, an image signal recording apparatus, an image signal reproducing method, an image signal reproducing apparatus, and an image signal recording disk medium that can reduce the time required for reproduction.

[0027]

SUMMARY OF THE INVENTION The present invention provides
Data-compressed I-pictures and temporally forward I-pictures
P-picture data compressed by motion compensation by Kucha
And I-picture or P-picture in the forward and backward direction in time
Data-compressed B picture with motion compensation
From a title composed of video information blocks including and
Is an optical disc on which digital image information is recorded.
The optical disc is composed of sectors having addresses.
And the video information block is the beginning of the sector.
The video information corresponding to the above title, which is arranged from the minute
Table information indicating the playback order of blocks and the above video information
Indicates the start address of the video information block for each block
The table information comes first from the digital image information above.
It is a part and is recorded as separate table information.
Are, the start address of the video information block, those
The sequence header sequence at the beginning of the video information block
Optical address, which is the address corresponding to
It is a school.

[0028]

EXAMPLES Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the optical disc recording / reproducing apparatus in the present embodiment, and FIG. 2 is a sector map diagram showing the data arrangement of the optical disc in the present embodiment. In FIG. 1, 1 is an A / D converter, 2 is an encoding means, 3 is a GOP file generating means, 4 is a GOP information detecting means, 5 is a GOP file order table (GS).
T) data generation means, 6 GOP information table / data generation means, 7 write control means, 8 data block construction means, 9 modulator, 10 laser drive circuit, 11 optical head control means, 12 optical Head, 13 is an optical disk, 14 is a sequence identification signal input means, 15 is a time position identification signal input means, 16 is a reproduction amplifier, 17 is a demodulator, 18 is an error correction means, 19 is a GOP file sequence table (GST) data detection Means, 20 is a GOP information table / data detecting means, 21 is a read control means, 2
2 is GOP continuation means, 23 is decoding means, and 24 is D /
A converter.

In FIG. 2, 31 is a boot sector for storing a boot code, 32 is a GOP file order table (hereinafter referred to as GST) area for storing arrangement information of GOP files, which will be described later, and 33 is GOP information. An area 34 is a user area.

In this embodiment, it is assumed that the sector addresses are arranged in ascending order from the inner circumference of the disc, and that the image signal compressed and encoded by the MPEG system is recorded on the optical disc. Also, MP
In the image data encoding method by the EG method, it is not always necessary to attach a sequence header to the front part of the GOP, but here, it is assumed that GOP3 does not have a sequence header. Further, each GOP shall be recorded at the variable data rate as described above. Further, the same reference numerals in the drawings indicate the same or corresponding parts.

Next, a recording operation in this embodiment will be described. First, the input image signal is input to the A / D converter 1 and converted into a digital image signal, which is then encoded in the encoding means 2 by the MPEG system and data compressed. As described above, the image signal encoded by the MPEG system is encoded with the GOP including a predetermined number of image signals as an encoding unit. Then, the encoded image signal is input to the GOP file generation means 3. Here, the encoded image signal has the layer (layer) structure shown in FIG. 7, as described above.
The sequence layer, which is the highest layer, is as shown in FIG.
Each GO is composed of GOPs (as described above, some have SH in the front part and some do not have SH in the front part).
P includes a GOP start code (not shown) at the beginning thereof.

Therefore, the GOP file generating means 3 detects the GOP start code included in each GOP,
This separates each GOP. Also, SH of each GOP
Detect the sequence start code in. Then, a GOP file which is one data file is generated by one separated GOP. The GOP file is input to the data block forming means 8 and also to the GOP information detecting means 4. Further, the GOP file generation means 3 generates a GOP start timing signal according to the detected GOP start code and inputs it to the write control means 7.

On the other hand, the sequence identification signal is input from the sequence identification signal input means 14 for inputting the sequence identification signal to the write control means 7, and the sequence start sector address indicating from which sector the data of each sequence is recorded. To generate. Then, from the sequence start sector address and the GOP start timing signal,
A GOP start sector address indicating from which sector each GOP file is recorded is generated, and GST data generation means 5 and GOP information table data generation means 6 are generated.
Output to. Here, GOP is sequentially performed from the sequence start sector address to the sectors of consecutive sector addresses.
The file shall be recorded. Note that the case of recording in a recordable free sector on the disc will be described later. Further, here, for convenience of description, No-1, No-
2, etc. will be described as the contents of the sequence identification signal.

Further, as described above, the GOP coded by the MPEG method in the coding means 2 has data (time code) or the like representing the time from the start time of the sequence to which the GOP belongs, at the beginning thereof. Each GO that is input in the GOP information detecting means 4 has
Information about a GOP such as a time code is detected from the GOP in the P file, and the file size and the coding rate of the GOP file to be input are also detected.

In the GST data generation means 5, the sequence identification signal input from the write control means 7 and each G
From the GOP start sector address generated for each OP,
For example, as shown in FIG. 4, each sequence (title,
GST table data storing sector addresses for determining the reproduction order of GOP files of each GOP forming each sequence is generated for the program) and output to the data block forming means 8.

The GOP information table / data generating means 6 generates a file name corresponding to each GOP file, and the G for each GOP input from the write control means 7 is generated.
The OP start sector address, and the time code indicating the time from the start of the sequence detected by the GOP information detecting means 6, the size of the GOP file, and the encoding rate correspond to each file name, for example, GOP information table data as shown in FIG. 3 is generated and output to the data block forming means 8. Here, the file name of each GOP can identify the sequence to which the GOP belongs.

The data block constructing means 8 performs processing such as adding an error correction code to the input GOP file, and then, corresponding to each GOP file, a data block of a predetermined format (hereinafter referred to as a GOP file). -It is described as a data block.). An end detection identification code is placed at the end of each GOP file data block. Similarly, in the data block construction means 8, a data block of a predetermined format (hereinafter, GST data block and GO, respectively) is input from the input GST data and GOP information table data.
It is referred to as a P information table data block. ).

Then, the GOP file data block is sent to the laser drive circuit 10 after being subjected to a predetermined modulation by the modulator 9, and the laser drive circuit 10 modulates the GOP file data block according to the modulation signal. Is output, and the optical head 12
It is recorded on the optical disk 13 via. At this time, each GOP file data block is recorded in the user area 34 in the sector map shown in FIG. 2 such that each GOP file is arranged from the head portion of the sector.

Further, like the GOP file data block, each data of the GST data block and the GOP information table data block is also modulated by the modulator 9, and then is moved onto the optical disk 13 by the optical head 12. Will be recorded. At this time, the GST data block and the GOP information table data block are recorded in the sectors of the GST area 32 and the GOP information area 33 in the sector map shown in FIG. 2, respectively.

On the other hand, the write control means 7 manages the sector address in which the GOP file, GST data and GOP information table data are recorded. That is,
By sequentially incrementing the GOP start sector address generated as described above, a sector address in which one GOP file is recorded (hereinafter referred to as a GOP recording sector address) is generated. And G
Each time the data of the OP file is completed, the GOP recording sector address is generated by sequentially incrementing from the next GOP start sector address. The GOP recording sector address thus generated is input to the optical head control means 11.

The optical head control means 11 controls the optical head 12 so as to access the sector on the optical disk corresponding to the GOP recording sector address while tracking. In this way, each GOP file data block is recorded so that each GOP file is located from the beginning of the GOP start sector address.

Similarly, the write control means 7 determines the GST data and the GOP information table from the sector address corresponding to the head sector of the GST area 32 and the sector address corresponding to the head sector of the GOP information area 33, respectively. A recording sector address for recording data is generated. The GOP recording sector address generated in this way is input to the optical head control means 11, and the optical head control means 11 causes the optical head 12 to access the sector on the optical disk according to the recording sector address. To control. In this way, GST data
The block and the GOP information table data block are the GST area 32 and the GOP information area 3 respectively.
It is recorded in 3 sectors.

As described above, one GOP (including a sequence header if it has a sequence header) is treated as one GOP file, and as shown in FIG. 2, each GOP file is It is sequentially recorded from the head portion of the sector indicated by the GOP start sector address of the user area 34. In the figure, for example, SH
1 and GOP1 are recorded as one GOP file 1 from the beginning of the sector of sector address n.
Even if the data of the GOP file 1 ends in the middle of a sector (in the figure, in the middle of the sector of the sector address (n + 5)), the following SH2 and GOP2 are one GOP file 2 and the next sector address. (N +
It is recorded from the beginning of the sector of 6). Similarly, for example, GOP3 is regarded as one GOP file from the beginning of the sector of sector address (n + 10).
SH4 and GOP4 are sequentially recorded as one GOP file from the beginning of the sector of sector address (n + 18). And GO that follows this
P files are also sequentially recorded in the same manner. In this case, G
The GOP start sector addresses of the OP1 file, GOP2 file, GOP3 file, and GOP4 file are n, (n + 5), (n + 10), and (n
+18).

Further, for each sequence (title, program), each GO that constitutes each sequence
The GOP file order table (GST) data storing the data for determining the playback order of the P GOP file is
It is recorded in the GOP file order table (GST) recording area 32 shown in FIG. 2 as described above. Figure 4 shows GS
The structure of GST data recorded in the T recording area 32 is shown, and the GST data in the figure is, for example, N
Each GOP file forming a sequence of sequence names (title name, program name) of o-1 is GO
P start sector address is address 1, address 2,
It is shown that the data is sequentially recorded in the sectors of address 3, address 4, ...

Then, for example, in order to reproduce the sequence having the sequence name (title name) of No-1, the GOP files forming the sequence are stored at the address 1,
Address 2, address 3, address 4, ... GOP
It suffices to sequentially read and reproduce from the sector which is the start sector address.

Furthermore, for each GOP file, GOP
The GOP information table data storing the data such as the file name indicating the GOP, the time from the start of the GOP sequence, the start sector address, the file size, the encoding rate, and the like is the GOP information table data shown in FIG. It is recorded in the information area 33. FIG. 3 shows table data recorded in the GOP information area 33.
GOP file of OP1, that is, the file name is "G
In the file of "OP1", the time from the start of the sequence is "00:12:00", the sector address at which the GOP is started (GOP start sector address) is "500000", and the file size is " 300
000 ”, indicating that the coding rate is“ 4.5 ”. Similarly, other GOP2, GOP3, GO
Also for P4 and the like, attributes such as a file name representing a GOP, a time from the start of a GOP sequence, a start sector address, a file size, and an encoding rate are recorded in the GOP information area 33 as table data.

Now, the operation during normal reproduction will be described. First, in order to read the GST data, as shown in FIG.
The read control means 21 generates a read sector address so that the optical head 12 accesses the GST recording area 32 on the optical disk 13 shown in FIG. 1, and the optical head 12 is controlled via the optical head control means 11. The GST data block read from the GST recording area 32 by the optical head 12 is reproduced by the reproduction amplifier 16
Amplified by and sent to the error correction means 18. In the error correction means 18, after processing such as error detection by the error detection code added in the GST data block, it is sent to the GST data detection means 19 as GST data.

Similarly, the GOP information table data recorded in the GOP information area 33 on the optical disk 12 is read out, and the GOP information table data detecting means 20 is read.
Sent to. Then, the read GST data and GOP information table data are stored in the GST data detecting means 19 and the GOP information table data detecting means 20, respectively.

The above operation may be performed immediately after the optical disk 23 is set in the apparatus or immediately after the recording and reproducing operations are started.

Further, a sequence identification signal for identifying the sequence to be reproduced is input from the sequence identification signal input means 14 to the GST data detection means 20 and the GST data detection means 20.
The data detection means 20 refers to the stored GST data, and thereby GOs in accordance with the sequence identification signal.
The start sector address of each GOP file indicating the playback order of the P file is determined.

For example, when the GST data as shown in FIG. 4 is read and stored and the content of the sequence identification signal is No-1, each GOP file forming the sequence has a start sector It is determined that the addresses are sequentially recorded in the sectors of address 1, address 2, address 3, address 4, ..., And the start sector address of each determined GOP file is output to the read control means 21. It

The read control means 21 sequentially increments from the input start sector address, which is the start sector address of the GOP file to be reproduced first, to generate a GOP read sector address. It Then, when the end is detected by the end detection signal of the data block of the GOP file input from the error correction means 18, the GOP to be reproduced next.
The GOP reproduction sector address is generated by sequentially incrementing from the start sector address 2 of the file. Similarly, GOP read sector addresses are generated in the same manner.

The GOP read sector address thus generated is sequentially sent to the optical head control means 11 to allow the optical head 12 to access the sector of the GOP read sector address.

Assuming that the GOP file is sequentially recorded in consecutive sectors in the order of reproduction, it is not necessary to refer to the GST data after the sequence start sector address is determined during reproduction. As shown in FIG. 5, the GOP files may be sequentially read by repeating the operation of jumping to the beginning of the next sector and reading the next GOP file when one GOP file is completed.

The GOP file data block sequentially read from each sector of the user area 34 by the optical head 12 is amplified by the reproduction amplifier 16 and then demodulated by the demodulator 17.
The signal is demodulated at and input to the error correction means 18. In the error correction means 18, after processing such as error correction is performed, G
As the data of the OP file, the sequential GOP continuation means 2
2 is input to the read control means 21 and the end identification signal for detecting the end of the GOP file data block is detected.

In the GOP continuation means 22, each GOP file in the separated state has a predetermined structure encoded by the MPEG system as shown in FIG. The GOP data in the stream (serial transmission signal) state is restored and input to the decoding means 23. The serialized GOP data is decoded by the decoding means 23.
At, it is decompressed and decoded into a digital image signal,
After being converted into an analog signal by the D / A converter 24,
It is output as an output image signal.

Next, the case of reproducing a GOP located in the middle of a certain sequence (title, program) will be described. It is assumed that the start sector address of each GOP file indicating the reproduction order of the GOP files according to the sequence to be reproduced is determined in the same manner as the above-described normal reproduction, and in FIG. GO file corresponding to the GOP located in
This will be described as P file 2.

First, the read control means 21 sends the start sector address of the GOP file 2, which is the GOP file corresponding to the GOP located in the middle of the sequence, to the optical head control means 11, and causes the optical head 12 to start the sector.
The sector at address (n + 6) is accessed. Then, as in the case of normal reproduction, the sectors are sequentially accessed from the sector of the start sector address (n + 6), and the GOP file data block read from the sector is reproduced by the reproduction amplifier 16, the demodulator 17, and the error correction unit. Means 18
Is input to the GOP continuation means 22 as data of a GOP file.

In the GOP continuation means 22, the GOP file 2 recorded in a state where the sector address is separated from (n + 6) to the middle of (n + 9) is recorded by the MPEG system as shown in FIG. Decoding means 2 has a predetermined encoded structure and restores it into GOP data in a continuous bit stream (serial transmission signal) state.
Input to 3. Where the first accessed sector
Since the GOP file 2 is recorded from the beginning of the sector of the address (n + 6), the data of the immediately preceding GOP1 is not read first. Therefore, the GOP data can be restored from the first read data, the decoding means 23 decodes the GOP data, and the D / A converter 24
Can be converted into an analog signal and output as an output image signal.

Thus, a certain sequence (title,
Even when a GOP located in the middle of the (program) is reproduced, the GO is accessed from the first accessed sector.
Since a part of the GOP immediately before P is not read and the GOP is read from the beginning of the accessed sector, it is possible to shorten the time required to reproduce and output the image signal.

Next, description will be made on a case where editing such as rewriting and joint photographing is performed for each GOP. As described above, in the recording state before editing, each GOP is recorded from the sector head portion as shown in FIG.
A case will be described in which the GOP files of the third and subsequent ones are newly rewritten with another GOP file. In such a case, G
Sector address recorded in OP3 (n + 10)
6 is newly created as another GOP file from the head portion of the sector of GOP3 ', GOP4', ...
Record sequentially as shown in.

In the disc thus rewritten, the GOP2 recorded before the editing is not affected by the rewriting and is recorded in the state before the editing. ), GOP2, which is the GOP before the edit point, cannot be played back and is missing.
No unnatural images are reproduced.

A case where an image signal is recorded / reproduced in recordable empty sectors dispersed on the disk in a medium in which re-recording (additional recording) is possible will be described. First,
GOP information table / data detecting means from the start sector address and file size of each GOP file in the GOP information table data read from the GOP information area 33 on the disc in the same manner as the normal reproduction described above. At 20, the free sector on the disk is discriminated and the sector address of the free sector is output to the write control means 7.

Then, the write control means 7 determines an empty sector area in which a GOP file to be additionally recorded can be continuously recorded from the file size extracted by the GOP information detecting means 4, and additionally records. The access of the optical head 12 is controlled in the same manner as the above-described recording operation so that the GOP file of the sequence is continuously recorded in the recordable continuous free sector area from the beginning of the sector.

On the other hand, in the GST data generating means 5, FIG.
Corresponding to the sequence to be additionally recorded as shown in
A GST indicating the start sector address of each GOP file forming each sequence is added and generated, and the GOP information table data generating means 6 includes a table including a GOP file name to be recorded and information related thereto. Generate data. And, as mentioned above,
Each table data is GS on the optical disk 13.
It is recorded in the T area 32 and the GOP information area 33.

In the case of reproducing the sequence recorded in the sectors dispersed on the disk in this way, for example, N
If the GOP file of the sequence o-2 is recorded in the sectors dispersed in the user area 4, the GST recorded in the GST area 32 is read at the time of reproduction, and by referring to it, the sequence No-2 From the start sector address of each GOP file indicating the playback order of the above, the playback order of each GOP file arranged in a distributed manner can be identified.

Thereafter, in the same manner as the above-mentioned normal reproduction, the read control means 21 selects the start sector of the GOP file to be reproduced first among the input start sector addresses.
Increment sequentially from address A, which is the address,
A GOP read sector address is generated. When the end of the data block of the GOP file is detected, the GOP reproduction sector address is generated by sequentially incrementing from the start sector address B of the GOP file to be reproduced next. Similarly, GO
The P read sector address is generated.

The GOP read sector address thus generated is sequentially sent to the optical head control means 11, the optical head 12 is made to access the sector of the GOP read sector address, and the image signal is read from the read data. Decrypt and output.

As described above, GOP file units can be recorded in the empty sectors dispersed on the disk, and the empty sectors can be effectively used.

Further, the case of reproducing a GOP at a desired time point from the start of a certain sequence (title, program) will be described. First, a sequence identification signal for identifying a sequence and a time position identification signal indicating a desired time point for reproduction are output from the sequence identification signal input means 14 and the time position identification signal input means 15 through G, respectively.
It is input to the OP information table / data detecting means 20.

In the same manner as described above, the GST data and the GOP information table data are read from the GST area 32 and the GOP information area 33 on the optical disk 13, respectively, and the GST data detecting means 27 and the GOP information are read. It is sent to and stored in the table / data detecting means 20. As shown in FIG. 3, the GOP information table data stores the time from the start of the sequence corresponding to the file name of each GOP, the start sector address of the GOP file, the file size, the encoding rate, etc. There is. The file name is recorded so that the sequence to which the GOP belongs can be identified.

Here, for example, when the content of the input sequence identification signal is No-1, and the GOP at the time of 00 minutes 13 seconds 00 from the start of the sequence is to be reproduced, the GOP information table Data detection means 2
In 0, the GOP information table data stored in advance is referred to, and the GOP file group belonging to the sequence indicated by the content No. 1 of the sequence identification signal is identified from the GOP file name. Then, by referring to the time from the sequence start corresponding to the GOP file group of the GOP information table data, as a GOP file whose time from the sequence start is 00: 13.00,
The GOP file whose file name is "GOP3" is specified, and its start sector address is identified as "500580". In this way, the GOP file at the desired point in time from the start of the sequence is specified and its G
The starting sector address of the OP file is identified (retrieved). Then, the start sector address thus identified (searched) is output to the GST data detecting means 19.

The GST data detecting means 19 refers to the GST data stored in advance and refers to the GOP information table.
From the start sector address of the GOP file specified by the data detection means 20, the start sector address is sequentially
Output to the read control means 21.

Thereafter, in the same manner as the above-mentioned normal reproduction, GO
GOP input from the P-file / data detecting means 20
Increment is sequentially performed from the start sector address until one GOP ends, and the GOP read sector
The address is generated. When the data block of the GOP file is detected, the GOP reproduction sector address is generated by sequentially incrementing from the start sector address of the GOP file to be reproduced next. Similarly, GOP read sector addresses are generated in the same manner.

The generated sector address is input to the optical head control means 11, the optical head 12 is accessed to the sector of the input sector address, and the data is read. The read data is decoded by the decoding means 23 via the reproduction amplifier 16, the demodulator 17, the error correction means 18, the GOP continuation means 22, and the D / A converter 24.
Is output as an output image signal.

As described above, since the GOP data is recorded from the head part of the sector, it is not necessary to search for the GOP discriminated in the sector, and it is recorded in the head part of the sector of the GOP file start sector address. G
Play from the OP in sequence.

As described above, when reproducing a GOP at a desired time point from the start of a certain sequence (title, program), the recorded sector of the target GOP can be identified easily and immediately. Further, since it is not necessary to search for the GOP determined in the sector, the time required to reproduce the image signal can be shortened.

By the way, in the above description, the MPEG method has been described as the compression encoding method of the image signal, but the compression encoding method is not particularly limited to this method, and the compression encoding using a predetermined number of images as an encoding unit. It goes without saying that any method can be used.

In addition, GO of the GOP information table data
The file name of the P file has been described as being capable of identifying the sequence to which the corresponding GOP belongs, but data for identifying the sequence to which the corresponding GOP belongs is separately arranged in the GOP information table for each file name. You may do it.

Further, in the above description, the GOP information table data is arranged such that the time from the start of the sequence is taken as the information indicating the position of the GOP in the sequence (title, program). Information indicating the position of the GOP in the program) may be, for example, information indicating the number of the GOP from the beginning of the sequence. In such a case, a signal indicating the number of the GOP to be searched from the beginning of the sequence can be input, and the GOP can be searched and reproduced.

[0081]

Since the present invention is configured as described above, it has the following effects.

[0082] The present invention can shorten the time required for demarcating out by reproducing the images signals. In addition, easy to edit, such as taking rewriting or tie in the sign-reduction unit,
Even if the editing point is reproduced, the reproduced image can be reproduced without being lost . Furthermore, it is also free sectors distributed on disk medium for recording and reproducing by utilizing effectively.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of an image signal recording device and an image signal reproducing device of the present invention.

FIG. 2 is a sector map diagram showing an area arrangement on an optical disc according to an embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of GOP information table data according to an embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of GOP file order table data according to an embodiment of the present invention.

FIG. 5 is a schematic diagram showing an access state of an optical head at the time of reproduction according to an embodiment of the present invention.

FIG. 6 is a schematic diagram showing a recording state of a GOP file in which GOP unit editing is performed according to an embodiment of the present invention.

FIG. 7 is a data structure diagram showing a data structure of an encoding method based on the MPEG system.

FIG. 8 is a data structure diagram showing a structure of a sequence layer of an encoding method based on the MPEG system.

[Fig. 9] Fig. 9 is a structural diagram showing the structure of a GOP in an encoding method according to the MPEG method.

FIG. 10: GOP encoded by the MPEG system
6A and 6B are schematic diagrams showing a method of recording at a variable rate and a method of recording at a fixed rate.

FIG. 11: GOP encoded by the MPEG system
FIG. 6 is a diagram showing an example of a temporal change in the amount of data per GOP in a method of recording data at a variable rate.

FIG. 12 is a diagram showing an example of the relationship between the image quality after decoding of an image signal encoded by the MPEG method and the data amount per 1 GOP.

[Explanation of symbols]

2 encoding means, 3 GOP file generation means, 4 G
ST data generation means, 5 GOP information table / data generation means, 7 writing control means, 13 optical disk,
19 GST data detecting means, 20 GOP information table / data detecting means, 21 read control means, 23
Decoding means, 32 GST area, 33 GOP information area.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hidetoshi Mishima No. 1 Baba Institute, Nagaokakyo City, Kyoto Prefecture Mitsubishi Electric Corporation Video System Development Laboratory (72) Inventor Asamura ▲ Yoshi ▼ Bench Institute Nagaokakyo, Kyoto Prefecture No. 1 Mitsubishi Electric Corporation Video System Development Laboratory (56) Reference JP-A-6-178288 (JP, A) JP-A-6-261303 (JP, A) JP-A-8-32934 (JP, A) JP-A-7-170488 (JP, A) Registered utility model 3004105 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04N 5/76-5/956 G11B 20/10

Claims (8)

(57) [Claims] 1. I-picture data compressed in a frame
And motion compensation by an I picture that is temporally forward.
Data-compressed P-pictures and temporally forward and backward
Add motion compensation by I picture or P picture of
Video information block including data-compressed B picture
Digital image information consisting of a title consisting of
A recorded optical disc, the optical disc comprising sectors having addresses.
Is, the image information block, distribution from the head portion of the sector
It is location, the reproduction order of the video information block corresponding to the title
Table information indicating the
Table information indicating the start address of the video information block and
Is the beginning of the digital image information,
Are recorded as separate table information, and the start address of the video information block is the video information.
Corresponds to the sector of the sequence header at the beginning of the block
An optical disc characterized in that it is an address. 2. The start address of the video information block
The table information shown in the table further includes the screen information corresponding to the above title.
Claim characterized in that it includes time information of the image information block
The optical disc according to item 1. 3. I-picture compressed in a frame
And motion compensation by an I picture that is temporally forward.
Data-compressed P-pictures and temporally forward and backward
Add motion compensation by I picture or P picture of
Video information block including data-compressed B picture
Digital image information consisting of a title composed of
, An optical disc composed of sectors having addresses
Recording the video information block from the beginning of the sector.
The location, the reproduction order of the video information block corresponding to the title
Table information indicating the
Table information indicating the start address of the video information block and
From the digital image information above,
The table information is recorded as separate table information, and the start address of the video information block is the video information.
Corresponds to the sector of the sequence header at the beginning of the block
Recording on an optical disk characterized by an address
Method. 4. The start address of the video information block
The table information shown in the table further includes the screen information corresponding to the above title.
Claim characterized in that it includes time information of the image information block
Item 3. The optical disc recording method according to Item 3. 5. I-picture data compressed in a frame
And motion compensation by an I picture that is temporally forward.
Data-compressed P-pictures and temporally forward and backward
Add motion compensation by I picture or P picture of
Video information block including data-compressed B picture
Digital image information consisting of a title composed of
, An optical disc composed of sectors having addresses
Recording means and the reproduction order of the video information block corresponding to the title.
Table information indicating the
Table information indicating the start address of the video information block and
From the digital image information above,
And means for recording as separate table information, wherein the video information block is allocated from the beginning of the sector.
It is intended to be location, the start address of the video information block, the video information
Corresponds to the sector of the sequence header at the beginning of the block
Recording on an optical disk characterized by an address
apparatus. 6. The start address of the video information block
The table information shown in the table further includes the screen information corresponding to the above title.
Claim characterized in that it includes time information of the image information block
Item 5. An optical disk recording device according to item 5. 7. A method for reproducing the optical disc according to claim 1.
Method, selecting the above-mentioned title and selecting the video information block corresponding to the above-mentioned selected title.
The table information indicating the reproduction order is reproduced, and the video information block to be reproduced is reproduced by the table information.
Table information that identifies the start address of the video information block
Information is reproduced, and the specified video information block and the above video information block are reproduced.
Based on the table information indicating the start address of the
And reproducing the video information block, after playing the video information block, from the table information indicating a reproduction order of the video information block corresponding to the title, to play the next video information block, and repeat the above series of operations A method for reproducing an optical disc, which is characterized by being performed. 8. A device for reproducing the optical disc according to claim 1.
And a means for selecting the title and a video information block corresponding to the selected title.
A means for reproducing table information indicating a reproduction order and a video information block to be reproduced by the table information.
Means for identifying and table information indicating the start address of the video information block
Means for reproducing information, the identified video information block, and the video information block.
Based on the table information indicating the start address of the
A means for reproducing the video information block, and a method for reproducing the video information block and then playing the title.
It is table information that indicates the playback order of the corresponding video information blocks.
Then, the next video information block is reproduced and the above series of operations are repeated to perform the optical data
Disc playback device.