JPH07147661A - Reproduction device/system for digital video disk - Google Patents

Abstract

PURPOSE:To store an MPEG system stream in an MCAV type optical disk and to reproduce the selected stream after having an access to it. CONSTITUTION:This reproduction device consists of an SCSI control circuit 103 which controls an optical disk driver, a storage circuit 102 which temporarily stores the data given from an optical disk, a control circuit 106 which contains a system stream decoding circuit and an MCAV type optical disk device. The general control information and the retrieving information are provided on the optical disk together with a system stream in the form of an MSDOS file. An access is made to the stream that is selected based on the retrieving information and the desired time stamp information is confirmed. Then the system stream is reproduced starting with its head.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital video disc reproducing apparatus and reproducing system for storing multimedia data such as images and sounds.

[0002]

2. Description of the Related Art Conventionally, a video disc 701 is shown in FIG.
A video signal or audio signal as shown in FIG. 21 is recorded in the spiral track 703 as shown in FIG. This recorded signal is voice I,
The voice II, the color signal and the black and white signal are frequency-modulated and recorded in the corresponding frequency bands, respectively, and the pilot signal is recorded in a single frequency wave.

The signal thus recorded on the video disc 701 is reproduced by a reproducing apparatus as shown in FIG. At this time, the reproduction of the video signal is performed in the following procedure. The light emitted from the laser light source 704 is the optical lens 7
After passing through 05, the beam splitter 706, the rotating mirror 707, and the objective lens 708, the light is focused on the surface of the video disc. The light reflected from the surface of the video disk passes through the objective lens again, is reflected by the rotating mirror and the beam splitter, and enters the photodetector 709. The incident light is converted into an electric signal by the photodetector, and the signal processing circuit 71
After being guided to 0, it is finally output as a reproduced video signal.

MPE is used as a compression method in moving image reproduction.
The G method is known. This is because, as shown in FIG. 23, the image data is the intra-frame encoded screens 190a, 19a.
0b (hereinafter, referred to as “I plane”), which is a frame that does not use compression due to correlation in the time axis direction, and intraframe coding screens 191a and 191b that are configured by using motion prediction or intraframe coding by the I plane. , 191c
(Hereinafter, referred to as “P plane”) and bidirectional predictive coding screens 192a, 192b, 193 predicted from the I and P planes.
a, 193b, 194a, 194b (hereinafter referred to as "B side").

Considering the reproduction of a moving image at an average of 5 Mbit / sec at 30 frames / sec, 1.25 Mbit on the I side, 1.25 Mbit on the P side,
Assuming that allocation is performed with 0.09 Mbits for the B side, a data transfer rate of about 40 Mbits / sec is instantaneously required during the I side reproduction.

[0006]

In the conventional video disc device as described above, since the data transfer rate is not constant depending on the frame in the moving image reproduction, the data transfer from the disc device cannot be instantaneously performed in the moving image reproduction. There was a problem.

In the conventional case where analog data is recorded as it is by FM-modulating the video signal, since the frame of the video signal is written according to the frame number, the information corresponding to the time stamp can be read directly from the disc. It is possible. However, since the optical disc for data has a structure that handles fixed-length digital data, the video signal cannot be stored as it is. Therefore, a method has been adopted in which a compression method such as MPEG1 or 2 is used, compression is performed together with digitization, and the data is stored as digital stream data.
In this case, since the compression rate differs depending on the nature of the input screen, the compressed data per unit time differs. Therefore, when these different (variable length) data are arranged in the fixed length data structure, the time information of the frame of the original image is scattered and its detection is not unique from the sector address. There was a problem that it was impossible to calculate.

There is also a problem that the stream data cannot be read as a file when connected to a computer.

[0009]

SUMMARY OF THE INVENTION In order to solve the problem that data transfer from a disk device is not in time for moving image reproduction, the present invention is a buffer for absorbing the difference in speed between moving image reproduction and disk reproduction. A memory is provided in the video disc reproducing apparatus, and the capacity of the buffer memory is set to be twice as much as the data capacity necessary for reproducing the intra-coded screen of the moving picture frame.

As a method of managing the buffer memory, the pointer for recording the data from the optical disk device in the buffer memory is always in the frame of the moving image frame rather than the pointer for reading the data from the buffer memory to the video / audio decoder. It is designed to be ahead of the data capacity required to reproduce the code screen.

Further, in order to solve the problem that the detection of a moving image frame cannot be uniquely determined from the sector address and the problem that the stream data cannot be read as a file, management information is added to the stream data and the MS is added.
It is arranged on the optical disk as a FAT file used by DOS, and general management information and search management information are added to the management information, and the relationship between the time stamp and the sector is written in advance in the search information.

Further, means for detecting the time stamp from the stream data is added.

Further, the target address is accessed from the search information to reproduce the target system stream.

Further, the target sector address is estimated from the time stamp and the average transfer rate of the stream data for access.

[0015]

According to the present invention, the video disc reproducing apparatus is provided with the buffer memory for absorbing the difference between the moving image reproducing speed and the disc reproducing speed, and the capacity of the buffer memory is set to the intra-frame encoded screen of the moving image frame. Since the data capacity required for reproduction is doubled, the data transfer from the optical disk device can be sent to the MPEG decoder without interruption during reproduction of a moving image, for example.

Further, the pointer for recording the data from the optical disk device in the buffer memory is always larger than the pointer for reading the data from the buffer memory to the video / audio decoder so that the data capacity necessary for reproducing the intra-frame coded screen of the moving image frame can be obtained. Since the preceding steps have been taken, the buffer memory can be managed smoothly.

By adding management information to stream data,
Since it is arranged on the optical disk as the FAT file used by MSDOS, it can be handled as a file from MSDOS, for example. Further, since the general management information and the search management information are added to the management information, it is possible to obtain and display the stream information without reproducing the stream. Further, since the relation between the time stamp and the sector is written in the search information in advance, it becomes possible to directly access the target stream by the sector and retrieve it.

Since a means for detecting the time stamp from the stream data is added, the time stamp can be detected.

Also, it has become possible to randomly reproduce a target system stream from the search information.

Further, since the target sector address is estimated and accessed from the time stamp and the average transfer rate of the stream data, a high speed search is possible.

[0021]

【Example】

Example 1. Example 1 of the present invention will be described below.
FIG. 1 is a block circuit diagram showing an embodiment of the present invention.
FIG. 1 shows an optical disk device (not shown) on which image / audio data compressed by the MPEG standard is recorded,
The disk reproducing device is located between an MPEG decoder (not shown) for decoding the image / audio data. The disk reproducing device 101a includes a buffer memory 102a,
SCSI protocol processing unit (hereinafter referred to as "SPC") 103a, DMA controller (hereinafter referred to as "DMA"
C ”) 104a, data discrimination circuit 105a, CP
The U106a, the ROM 107a, the RAM 108a, the selector 109a, and the command register 110a, and an optical disk device (not shown) and SCSI (Smal).
l Computer System Interfa
ce) connected by a bus 112a and not shown MPEG
The decoder is connected to the video data stream signal line 114a, the audio data stream signal line 115a, and the data request signal line 116a. An upper system (not shown) is an I / O signal 117a for knowing the state of the CPU 106a, an interrupt signal 118a, a command register 1
It is connected by a signal 120a for sending command data to 10a.

The main function of the disc reproducing apparatus 101a is to enable the variable data transfer rate required by the MPEG decoder for the data sent from the optical disk apparatus at a substantially constant data transfer rate.

In FIG. 1, the buffer memory 102 is used for this purpose.
By providing a, the data flow is supplied to the MPEG decoder without interruption.

FIG. 2 is a flow chart of the operation in data reproduction.

First, in S1, a command for data reproduction is written from the upper system (not shown) into the command register 110a from 120a. However, in a host system (not shown), the CPU 106a sets the command register 110a to 1
Signal 1 in advance that it is not accessed from 19a
Confirm from 17a. An interrupt signal 118a for notifying the CPU 106a of a command from the host system
Is used to notify the CPU 106a of the existence of the command.

In S2, the CPU 106a obtains the command of the command register 110a from the signal 119a in response to the notification, and the SPC 103a issues the reproduction command to an optical disk device (not shown) according to the SCSI protocol.

Next, in S3, the SPC 103a sends the reproduction command to the optical disk device (not shown) by SCS.
Issue according to I protocol. SCSI bus 112
The data reproduced from the optical disc device (not shown) via a is temporarily stored in the buffer memory 102a, and the data stored in the buffer memory by the data request signal 116a of the MPEG decoder (not shown) is sent out from the system stream signal line 113a. .

Next, in S4, the SCSI bus 11
Data reproduced from an optical disk device (not shown) via 2a is stored in the temporary buffer memory 102a via the data bus 121a. The stored data is sent from the buffer memory 102a onto the system stream signal line 113a by a data request signal 116a of an MPEG decoder (not shown).

The structure of the buffer memory 102a is similar to that of a general-purpose RAM, and its external signals include an address bus, a data bus and a write / read control signal.
Buffer memory 102a stores data from the optical disk device.
Pointer value for recording to the buffer memory 102a
Is performed by the DMAC 104a through the control signal 122a of the write / read control signal and the address bus indicating the pointer value when reading from the video / audio decoder. Note that data access to the buffer memory is performed by direct memory access (DMA), not through the CPU 106a.

The data discriminating circuit 105a has a function of separating the composite data of the image data, the audio data and the time code recorded on the optical disc into the necessary image data and audio data.

The ROM 107a stores the contents for controlling the flow, and reproduces and outputs the image / sound data stored in the optical disk by a command of a host system (not shown). Command register 11
0a has an execution end status register, and notifies the upper system of the execution end of the above command. In addition,
The RAM 108a is a work RAM for temporary saving of the CPU 106a.

In the first embodiment, the compression method is MPEG.
Although the method has been described, it is needless to say that it is not particularly limited to this method.

Example 2. Another embodiment 2 of the present invention will be described below. FIG. 3 shows that the command register 110b notifies the disc player of the arrival of a command from a host system (not shown).
106b reproduces the disc by the command notification signal 118b. Note that each component of FIG. 3 has the same function as that in which the subscript a of each symbol in FIG. 1 is replaced with the subscript b, except for the command notification signal 118b.

Example 3. Another embodiment 3 of the present invention will be described below. In FIG. 4, a command from a host system (not shown) and a command execution end status from the playback device are transmitted via the I / O bus 117c of the CPU 106c, and the same operation is performed.

A host system not shown is the I / O bus 1.
17c knows the operating state of the CPU 106c,
If the U 106c is in the command receivable state, the command is transmitted via the I / O bus 117c. Note that each component of FIG. 4 has the same function as that obtained by replacing the subscript a of each symbol in FIG. 1 with the subscript c, except for the I / O signal 117c.

Example 4. Example 4 of the present invention will be described below. FIG. 5 shows a method of managing the buffer memories 102a, 102b, 102c shown in the first to third embodiments, and the buffer capacity is twice as large as one frame of the I plane. Here, the pointer for recording the data from the optical disk device in the buffer memory is set to P
d, Pm is a pointer for reading from the buffer memory to the video / audio decoder. These are the DMAC 104a,
It is an address value of the buffer memory generated by 104b and 104c.

The disc reproducing apparatuses 101a, 101b, 101c (hereinafter referred to as "101") which have received the reproducing command store the data from the optical disc apparatus in the buffer memory 102 after storing the data for one frame of the I plane. Pd = Pd0), MPEG from buffer memory 102
The data is sent to the decoder (Pm = Pm0).

Also, by maintaining the difference between Pd and Pm for one frame of the I-plane or more, the P-plane (for example, 191c), the B-plane (for example, 194a), and the B-plane (for example, 194b) are temporarily sent to the MPEG decoder. Even (Pm = Pm1), the data for the next I plane (for example, 190b) is stored in the buffer memory 102.
Pm does not pass Pd.

However, the reproduction data is the buffer memory 10
2 or less, or the buffer memory 10
This is not the case when the capacity up to the end of reproduction when reproducing long data exceeding the capacity of 2 is less than the buffer memory.

On the other hand, when the pointer reaches the final address of the buffer memory 102, the buffer memory 102 is configured as a ring buffer to set the pointer to the start address and continue the processing. However, P
Control so that d does not pass Pm.

Example 5. Example 5 of the present invention will be described below. In the fourth embodiment, the capacity of the buffer memory is doubled for one frame on the I surface, but the same operation can be expected even if the buffer capacity exceeds twice.

Example 6. Example 6 of the present invention will be described below. FIG. 6 defines the arrangement of data on the optical disc. Here, since the physical sector addresses of the optical disk are arranged in ascending order from the inner circumference, the arrangement is described starting from the inner circumference. Data on the optical disc includes a boot sector 301 that stores a boot code from the inner circumference, and a file allocation table (F that stores layout information of files to be described later).
AT) 302, directory entry 303, and
Files A, B, ... 304, 305, ... And a free area 306 without files.

These structures are basically similar to the structure of the MSDOS single-partition floppy compliant with the 3.5 "MO IBM format. Therefore, it is easy to obtain the purpose from the conventional MSDOS file system. The system stream to be played can be searched as a file name, for example, file A and file B here.

FIG. 7 shows the structure of the file A 304 as a representative. The file A is system stream management information 3 that stores information for managing the system stream.
11 and a system stream 312 in which the main body of the system stream, that is, the image, the sound, etc. are arranged in a packet together with a time stamp and various attribute information based on the MPEG standard.

Further, FIG. 8 shows the structure of the system stream management information 311. System stream management information 3
Reference numeral 11 denotes a management information header 321, which stores information regarding access to management information, general management information 322, which stores general information about the digital stream 312, and search management information 323, which stores search information for the digital stream 312.
Consists of.

Further, FIG. 9 shows the structure of the management information header 321. The management information header 321 includes a management information identification code 331, which is an arbitrary pattern from which a management information area can be identified, a general management information length 332 that stores the length (number of bytes) of the general management information 322, The search management information length 333 stores the length (number of bytes) of the search management information 323.

Further, FIG. 10 shows the structure of the general management information 322. The general management information 322 includes work information 341 that stores information about works such as the issue date, work name, and author name.
Disc-specific information 3 that stores information about the disc and writing, such as the date of writing and the name of the writing device.
42, and system stream information 343 that stores information about the configuration of the system stream, such as MPEG encoding format and data rate.

Further, FIG. 11 shows the structure of the search management information 323. The system stream 312 is divided into several substreams according to its content. The search management information 32 stores the search information of this substream.
It is 3. The search management information has a pointer 351 to the search information of the substream 2, a search information 352 of the first substream 1, a pointer 353 to the search information of the substream 3, and a search information 35 of the substream 2 at the beginning.
4, pointer 355 to search information of substream 4
And the search information 356 for substream 3,
It is a chain with pointers for substream search information. By traversing the chain from the beginning,
It becomes possible to read out the search information of the target substream.

Further, FIG. 12 shows the structure of the search information 352 of the substream 1 in the sixth embodiment. It goes without saying that this configuration is similar to the search information of other substreams. Compressed video data and audio data are recorded in the system stream together with time information. The time information is stored in the form of a time stamp code. The search information is the start stamp code 3 which is the time stamp code at the beginning of the subsystem.
61, a sector address 362 including the data of the stamp code, and substream related information 363 such as a subtitle of the substream and a brief description. The data length of this 363 is variable.

Example 7. Example 7 of the present invention will be described below. FIG. 13 shows the structure of the search information 352 for substream 1 in the seventh embodiment. It goes without saying that this configuration is similar to the search information of other substreams. Compressed video data and audio data are recorded in the system stream together with time information.
The time information is stored in the form of a time stamp code. The search information includes a start stamp code 361, which is the top time stamp code of the subsystem, an end time stamp code 364, which is the last time stamp code, a start sector address 362 and end sector address including the data of the stamp code, It includes substream related information 363 such as a subtitle of the substream and a brief description. The data length of this 363 is variable.

Example 8. Example 8 of the present invention will be described below. FIG. 14 shows the structure of the search information 352 for substream 1 in the eighth embodiment. It goes without saying that this configuration is similar to the search information of other substreams. Compressed video data and audio data are recorded in the system stream together with time information.
The time information is stored in the form of a time stamp code. The search information includes a start stamp code 361 that is a time stamp code at the beginning of the sub stream, and an end time stamp code 364 that is a last time stamp code. Sub stream related information 363 such as a sub title of the sub stream and a brief description. This 3
The data length of 63 is variable.

Example 9. Example 9 of the present invention will be described below. In FIG. 15, 501 is an optical disk, 5
02 is an optical disk drive, 503 is a buffer, 504
Is a time stamp extraction circuit, 505 is a SCSI controller, 506 is a CPU, 507 is a host computer,
Reference numeral 508 is a time stamp signal, and 509 is a start pointer signal.

The optical disc 501 is an MCAV type optical disc in which an MPEG system stream is stored. The optical disk drive 502 drives the optical disk 501, the buffer 503, and the time stamp extraction circuit 5
04 is a circuit having a function of outputting an MPEG system stream. The buffer 503 takes in the data stream output from the optical disk drive 502,
A moving image corresponding to the desired time code is output to the SCSI controller by the start pointer signal 509 from the PU 506. The time stamp extraction circuit 504 is a circuit which extracts a time stamp from the MPEG system stream from the optical disc drive 502 and outputs this code to the CPU.

By constructing such hardware, it becomes easy to access in time when an MPEG data stream is handled in the data format which is conventionally managed in sector units.

The data stream from the optical disk drive 502 is input to the time stamp extraction circuit 504, the time information of this stream is clarified, and the buffer 503 which stores the stream is controlled from the time information to control the MPEG moving picture. Access control is enabled by time code.

Example 10. Example 10 of the present invention will be described below. In FIG. 16, 501 is an optical disk,
503 is a buffer, 505 is a SCSI controller, 5
06 is a CPU, 507 is a host computer, 508 is a time stamp signal, 509 is a start pointer signal, 51
Reference numeral 0 is an optical disk drive.

The optical disc 501 is an MCAV type optical disc, in which the MPEG system stream is stored, and the time stamps are formatted in advance in a separated form. The optical disc drive 510 drives the optical disc 501 and causes the buffer 503 to perform MPE.
It is accompanied by a circuit for outputting the G system stream and outputting the time stamp code 508 to the CPU 506. The buffer 503 takes in the data stream output from the optical disc drive 510, and outputs a moving image corresponding to the desired time code to the SCSI controller by the start pointer signal 509 from the CPU 506.

With such a hardware configuration, even when desired data starts in the middle of a sector, it is possible to mask an unnecessary portion of the sector head, and access control can be performed by a time code of an MPEG moving image. And

Example 11. Example 11 of the present invention will be described below. FIG. 17 shows a flowchart for reproducing the system stream of the seventh embodiment with the hardware configuration of the ninth embodiment. 401 is the beginning of the file, 40
Reference numeral 2 is the reading of the management information header, 403 is the reading of the general management information, 404 is the reading of the search management information, 405.
Is the display of work information, disc individual information, and subtitle,
406 is waiting for selection input by the user, 407 is retrieval information (sector address and time stamp) of the selected subsystem stream, and 408 is retrieval information (sector address and sector information of the next subsystem stream of the selected subsystem stream. Timestamp) read, 409 seek to start sector address, 41
0 is a seek to the start time stamp, 411 is a reproduction of the subsystem stream bit stream, 412 is a time stamp extraction process, and 413 is an end time stamp detection process.

Bit stream reproduction in the system stream is performed according to the flowchart of FIG. First, the management information in the system stream is read out and a table of contents is displayed.

A specific system stream is cued from the optical disc (401), and the general management information length and the search management information length are read from the management information header in the system stream (402). Then, the general management information (work information, disc individual information, system stream information) is read based on the read length of each management information (4
03), the title of each subsystem stream in the search management information is read (404).

Further, the work information, disc individual information, and the title of each subsystem stream are displayed based on the read information (405). When displaying, the display screen and the user interface are configured so that the user can see the displayed contents and select the title of the subsystem stream that the user wants to see. Then, it waits for the input of subsystem stream selection from the user (40
6). When the subsystem stream is selected, reproduction of the subsystem stream is started.

The reproduction of the subsystem stream is performed as follows. From the search information of the subsystem stream selected by the user, the sector address (start sector address) at which the reading of the bitstream is started and the time stamp (start time stamp) are read (407). Then, from the search information of the subsystem stream next to the subsystem stream selected by the user, the sector address (end sector address) and the time stamp (end time stamp) at which the reading of the bit stream ends are read (408).

Then, based on the retrieved search information, a seek operation to the start sector address is performed (409). Then, the time stamp in the sector is extracted by the built-in time stamp extraction circuit (504), and seek to the start time stamp is performed while comparing with the start time stamp (410).

Since the bit stream of the subsystem stream selected by the user is cued in steps 409 and 410, the bit stream of the subsystem stream is reproduced according to the system stream information read in step 403 ( 411).

Then, while reproducing the bit stream, the built-in time stamp extraction circuit 504 extracts the time stamp (412) and determines the end of the bit stream reproduction (413). In step 413, the extracted time stamp is compared with the end time stamp read in step 408. As a result of the comparison in the process 413, the reproduction of the bit stream is continued until the decoded time stamp exceeds the end time stamp, and when the time stamp is exceeded, the reproduction of the bit stream is ended, and the process returns to the process 405.

By inserting the processing equivalent to the processing from the processing 405 to the processing 412 at the time of reproducing the bit stream, the interactivity can be enhanced.

Example 12 Example 12 of the present invention will be described below. FIG. 18 shows a flowchart for reproducing the system stream of the seventh embodiment with the hardware configuration of the tenth embodiment. The processes 401 to 406 are the same as those in the eleventh embodiment, and thus the description thereof will be omitted. Reference numeral 414 is the retrieval of the search information (sector address) of the selected subsystem stream, 415 is the retrieval of the search information (sector address) of the subsystem stream next to the selected subsystem stream, 416 is the detection of the sector address, 417 Indicates the processing of detecting the end sector address.

The bit stream in the system stream is reproduced according to the flowchart of FIG. here,
The procedure up to the process of reading the management information in the system stream, displaying the table of contents, and selecting the desired subsystem stream by the user is the same as that in the eleventh embodiment, so the reproduction of the subsystem stream will be described below.

The reproduction of the subsystem stream is performed as follows. The sector address (start sector address) at which the reading of the bitstream is started is read from the search information of the subsystem stream selected by the user (4
14). Then, from the search information of the subsystem stream next to the subsystem stream selected by the user, the sector address (end sector address) at which the reading of the bitstream is finished is read (415).

Then, based on the retrieved search information, a seek operation to the start sector address is performed (409).

Since the bit stream of the subsystem stream selected by the user is cued in step 409, the bit stream of the subsystem stream is reproduced according to the system stream information read in step 403 (411). .

Then, while reproducing the bit stream, the sector address is detected (416) and the end of the bit stream reproduction is judged (417). Process 41
7 compares the detected sector address with the end sector address read in the process 415. As a result of the comparison in the process 417, the reproduction of the bitstream is continued until the detected sector address exceeds the end sector address, and when the detected sector address exceeds the end sector address, the reproduction of the bitstream is ended, and the process 405 is performed.
Return to.

By inserting the processing equivalent to the processing from the processing 405 to the processing 412 at the time of reproducing the bit stream, the interactivity can be enhanced.

Example 13 Example 13 of the present invention will be described below. Example 9 of claim 4 represented in FIG.
In the digital video disc reproducing apparatus having the same configuration as the above, the MPEG system stream stored on the disc 501 is read by the disc reproducing apparatus 502. This reproduced system stream is input to the time stamp extraction circuit 504, and the CPU 506 obtains the time stamp code 508 of the system stream being reproduced at that time. Here, the operation in the case where the certain target time stamp is the user's target time stamp obtained through the user interface means or the time stamp instructed from the CPU 506 will be described with reference to FIG.

The CPU 506 compares the time stamp currently being reproduced with the target time stamp, and if the two are different, performs a seek operation. It is the target sector distance predicted value calculation processing 601 of FIG. 19 that determines the seek amount at this time.

Next, as shown in FIG. 19, the target sector distance predicted value calculation processing 601 uses the time stamp currently being reproduced and the data rate of the system stream currently being reproduced as information, and the data of the target time stamp. Calculate the sector number on the disk that will be stored.

As the reproduction data rate, for example, a means for measuring an instantaneous data rate at the time of calculation can be used, or, for example, the reproduction data rate can be constantly integrated and averaged and the value can be adopted. By multiplying this reproduction data rate by the reproduction time difference up to the target time stamp, the data amount up to the target sector where the data of the target time stamp will be stored can be obtained.

Since the amount of data per unit sector is known in the logical format of the digital video disc, the difference between the current sector number and the target sector number can be known. Therefore, when the distance is positive, the seek is performed in the direction in which the sector number increases, and when the distance is negative, in the direction in which the sector number decreases, the seek for the difference between the sector numbers is performed.

Next, the CPU 506 issues a seek command to the target sector number obtained by the predicted value calculation processing 601 of the distance to the target sector, causes the seek operation processing 602 to be performed, and reaches the sector. And then play the system stream on the sector. With this playback,
The time stamp extraction circuit obtains the time stamp of the system stream stored on the newly arrived sector.

Since this time stamp is the time stamp in the target sector predicted using the reproduction data rate, there may be a case where it does not match the original target time stamp due to the prediction error.

Therefore, the target time stamp judgment processing 60
At 3, it is determined whether the time stamp of the system stream currently being reproduced is equal to the target time stamp. If the current time stamp is earlier than the target time stamp, the sector on the disc in which the system stream having the target time stamp is stored is on the rear side in the recording time axis direction, and vice versa. If the current time stamp is later than the target time stamp, the sector on the disc in which the system stream having the target time stamp is stored is on the front side in the recording time axis direction.

Therefore, the seek operation is performed again to reach the sector in which the target time stamp is recorded. In order to determine the seek amount of the seek operation performed here, the process returns to the previous distance prediction value calculation processing 601, and the above-described work is repeated.

By performing the series of operations once or a plurality of times, the target time stamp determination processing 603 determines that the time stamp of the system stream stored in the sector currently being reproduced matches the target time stamp. If so, the next buffer move processing 604
I do.

In this buffer movement processing 604, the pointer of the reproduction buffer is set to the head of the target system stream in order to reproduce the system stream including the target time stamp from the beginning.

Next, when the reproduction of the disc is started, the target system stream is reproduced from the beginning.
This reproduction output is output to the MPEG decoder (605),
Get playback data.

[0087]

In the video disc reproducing apparatus of the present invention, since the buffer capacity is twice the capacity of the intra-frame coded screen, data transfer can be performed without interruption in response to the data request of the MPEG decoder, and data reproduction can be performed. Improves reliability.

Further, as the management of the buffer memory, the recording pointer for recording the data from the video disk drive in the buffer memory is one frame or more of the intra-coded screen than the read pointer for reading the data from the buffer memory to the MPEG decoder. Since it is managed as before, the transfer on the MPEG decoder side is instantaneously SCSI
Even if it becomes faster than the side data, the read pointer does not overtake the record pointer, and the reliability of data reproduction is improved.

Since the system stream is arranged on the optical disc as a FAT file used by MSDOS, it can be handled as a file from MSDOS, and the system stream can be edited by a personal computer other than the video disc reproducing apparatus. The effect that it becomes easy to edit is obtained.

Since the means for extracting the time stamp from the stream data is added to the video disc reproducing apparatus,
The time stamp can be extracted, the system stream can be accessed using the extracted time stamp, and the effect that the target system stream can be accessed randomly and at high speed is obtained.

Since the general management information is posted to the operator so that the operator can select the desired system stream, the interactivity of the video disc reproducing apparatus is improved, and the information selected by the operator is By accessing the selected data from the search management information, it is possible to easily and quickly access the desired data.

When the circuit for detecting the time stamp data is provided, the target sector is predicted and accessed from the average data rate of the stream data, so that the sector having the target time stamp can be accessed at high speed. There is an effect.

[Brief description of drawings]

FIG. 1 is a block circuit diagram of a video disk reproducing device according to a first embodiment of the present invention.

FIG. 2 is a flowchart of a second embodiment.

FIG. 3 is a block circuit diagram of a video disk reproducing device according to a second embodiment of the present invention.

FIG. 4 is a block circuit diagram of a video disk reproducing device in embodiment 3 of the present invention.

FIG. 5 is a configuration diagram of a buffer memory according to a fourth embodiment of the present invention.

FIG. 6 is a file layout diagram on an optical disc according to a sixth embodiment of the present invention.

FIG. 7 is a configuration diagram of files according to a sixth embodiment.

FIG. 8 is a configuration diagram of system stream management information according to the sixth embodiment.

FIG. 9 is a configuration diagram of a management information header according to the sixth embodiment.

FIG. 10 is a configuration diagram of general management information according to the sixth embodiment.

FIG. 11 is a configuration diagram of search management information according to the sixth embodiment.

FIG. 12 is a configuration diagram of a subsystem stream according to the sixth embodiment.

FIG. 13 is a configuration diagram of a subsystem stream according to the seventh embodiment of this invention.

FIG. 14 is a configuration diagram of a subsystem stream according to an eighth embodiment of the present invention.

FIG. 15 is a configuration diagram of a video disc reproducing apparatus including a time stamp extracting circuit according to a ninth embodiment of the present invention.

[Fig. 16] Fig. 16 is a configuration diagram of a video disc playback device not including a time stamp extraction circuit according to a tenth embodiment of the present invention.

FIG. 17 is a flowchart of digital video disc reproduction of Embodiment 11 of the present invention.

FIG. 18 is a flowchart of reproducing a digital video disc according to Example 12 of the present invention.

FIG. 19 is a target time stamp cue flowchart for reproducing a digital video disc according to a thirteenth embodiment of the present invention.

FIG. 20 is a schematic configuration diagram of a video disc.

FIG. 21 is a configuration diagram of a video signal.

FIG. 22 is a schematic configuration diagram of a video playback device.

FIG. 23 is a configuration diagram of a moving image reproduction frame on the time axis.

[Explanation of symbols]

 101 Video Disc Playback Device 102 Buffer Memory 103 SCSI Protocol Processing Circuit (SPC) 104 DMA Controller (DMAC) 105 Data Discrimination Circuit 106 CPU 107 ROM 108 RAM 110 Command Register 112 SCSI Bus 113 System Stream Signal Line 114 Image Data Stream Signal Line 115 Audio data stream signal line 190 Intra-frame encoding screen (I-side) 191 Inter-frame predictive encoding screen (P-side) 192 Bi-directional predictive encoding screen (B-side) 193 Bi-directional predictive encoding screen (B-side) 194 Both Predictive coding screen (B side) 301 Boot sector 302 File allocation table (FAT) 303 Directory entry 304 File 311 System stream management information 312 Stem stream 321 Management information header 322 General management information 323 Search management information 331 Management information identification code 332 General management information length 333 Search management information length 341 Work information 342 Disc individual information 343 System stream information 351 Pointer to next search information 352 Sub System stream search information 361 Start stamp code 362 Start sector address 363 Subsystem stream related information 364 End stamp code 365 End sector address 501 Optical disc 502 Optical disc drive 503 Buffer 504 Time stamp extraction circuit 505 SCSI controller 506 CPU 507 Host computer 508 Time stamp Signal 509 Start pointer signal 510 Optical disc drive

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[Procedure amendment]

[Submission date] July 5, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

MPE is used as a compression method in moving image reproduction.
The G method is known. This is because, as shown in FIG. 23, the image data is the intra-frame encoded screens 190a, 19a.
0b (hereinafter referred to as “I plane ” ), which is not used for compression by correlation in the time axis direction, and an interframe predictive coding screen 191a configured using motion prediction or intraframe coding by I plane, 191b, 191
bidirectional predictive coding screens 192a, 192b, 19 predicted from c (hereinafter referred to as "P plane") and I and P planes.
3a, 193b, 194a, 194b (hereinafter, "B side")
Called)).

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

In the conventional case where analog data is recorded as it is by FM-modulating the video signal, since the frame of the video signal is written according to the frame number, the information corresponding to the time stamp can be read directly from the disc. It is possible. However, since the optical disc for data has a structure that handles fixed-length digital data, the video signal cannot be stored as it is. Therefore, a method has been adopted in which a compression method such as MPEG1 or 2 is used, compression is performed together with digitization, and the data is stored as digital stream data.
In this case, since the compression rate differs depending on the nature of the input screen, the compressed data per unit time differs. Thus, when arranging these different (variable length) Data in fixed-length data structures, present in the original frame that time information if Rabara image, also the detection, not uniquely determined from the sector address, That is, there was a problem that calculation was impossible.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0045

[Correction method] Change

[Correction content]

Further, FIG. 8 shows the structure of the system stream management information 311. System stream management information 3
11, management information header 321, the search control information storing administrative information 322 stores general information of the system stream 312, the retrieval information system strike <br/> stream 312 that contains information about the access management information 323
Consists of.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0075

[Correction method] Change

[Correction content]

Example 13 Example 13 of the present invention will be described below. Example 9 of claim 4 represented in FIG.
In the digital video disc reproducing apparatus having the same configuration as the above, the MPEG system stream stored on the disc 501 is read by the disc reproducing apparatus 502. This reproduced system stream is input to the time stamp extraction circuit 504, and the CPU 506 obtains the time stamp code 508 of the system stream being reproduced at that time. Here, the time stamp of a certain object, for example object timestamp and user obtained through the user interface unit, will be described with reference to FIG. 19 the operation when a time stamp is commanded from the CPU 506.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] Explanation of code

[Correction method] Change

[Correction content]

[Explanation of Codes] 101 Video Disc Playback Device 102 Buffer Memory 103 SCSI Protocol Processing Circuit (SPC) 104 DMA Controller (DMAC) 105 Data Discrimination Circuit 106 CPU 107 ROM 108 RAM 110 Command Register 112 SCSI Bus 113 System Stream Signal Line 114 Image Data stream signal line 115 Audio data stream signal line 190 Intra-frame encoding screen (I-side) 191 Inter-frame predictive encoding screen (P-side) 192 Bi-directional predictive encoding screen (B-side) 193 Bi-directional predictive encoding screen ( B side) 194 Bidirectional predictive coding screen (B side) 301 Boot sector 302 File allocation table (FAT) 303 Directory entry 304 File 311 System stream pipe Management information 312 System stream 321 Management information header 322 General management information 323 Search management information 331 Management information identification code 332 General management information length 333 Search management information length 341 Work information 342 Disc specific information 343 System stream information 351 Next search information Pointer 352 Subsystem stream search information 361 Start stamp code 362 Start sector address 363 Subsystem stream related information 364 End stamp code 365 End sector address 501 Optical disc 502 Optical disc drive 503 Buffer 504 Time stamp extraction circuit 505 SCSI controller 506 CPU 507 Host computer 508 timestamp signal 509 start pointer signal 510 optical disc drive 7 1 Videos 702 pit 703 tracks 704 laser beam 705 optical lenses 706 beam splitter 707 rotates mirror 708 objective lens 709 optical detector 710 signal processing circuit

[Procedure correction 6]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 5

[Correction method] Change

[Correction content]

[Figure 5]

[Procedure Amendment 7]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 6

[Correction method] Change

[Correction content]

[Figure 6]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location H04N 5/91 (72) Inventor Ohata ▲ Hiro ▼ yuki Nagaokakyo City Baba Institute 1 Mitsubishi Electric Stock Association (72) Inventor Ken Nishikawa, No. 1 Baba Institute, Nagaokakyo City Mitsubishi Electric Co., Ltd. Video System Development Laboratory

Claims (6)

[Claims] 1. A reproducing apparatus for a digital video disc in which compressed image and audio data is recorded, wherein a capacity of a buffer memory for storing reproduced data when decoding the data and reproducing one frame is set to one frame. The digital video disc reproducing apparatus is characterized in that it is formed to have a capacity more than twice as large as the largest capacity of the reproduced data of. 2. A digital video disc reproducing apparatus having a buffer memory, a recording pointer for recording data reproduced from a video disc in the buffer memory, and a read pointer for reading data for decoding from the buffer memory. Is provided, and the distance between the recording pointer and the reading pointer is
Decodes compressed image data and audio data, and 1
A digital video disc reproducing method characterized in that management is performed such that the frame is at least before the largest capacity of the data required for reproducing the frame. 3. An optical disk reproducing apparatus having an optical disk storing a digital video system stream, a means for detecting data from the optical disk, a means for storing data, and a means for converting the data into video, and general management information and time. A digital video disc reproducing apparatus characterized in that a system stream is converted into a FAT file by combining search management information in which a relation between a stamp and a sector is entered. 4. A time stamp is extracted from data in an optical disk reproducing apparatus having an optical disk storing a digital video system stream, a means for detecting data from the optical disk, a means for storing data, and a means for converting the data into video. A digital video disc reproducing apparatus having means for performing. 5. The digital video disc reproducing apparatus according to claim 3, wherein the general management information is presented to the operator of the reproducing apparatus, and the target selection data is accessed and reproduced from the operator's selection information and the search management information. A digital video disc playback system characterized in that 6. The digital video disk reproducing apparatus according to claim 4, wherein the sector address of the optical disk is predicted from the time stamp code and the average data transfer rate, and the sector having the target time stamp code is accessed. And digital video disc playback system.