JP2003018527A - Recording and reproducing device, computer readable recording medium, and program thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording and reproducing device which can prevent the interruption of reproduction even if an instruction to fast-forward is given during chasing reproduction of an optical disc. SOLUTION: When an instruction to fast-forward is sent out by a user, a regeneration data controlling section 10 selects N picture data which satisfy the following expression from the picture data which constitutes VOBU in a regeneration buffer 5, and then gets the N selected picture data output onto an MPEG decorder 6: N×Vf≈TP1, TP1>=TPO+TW, where Vf is the time required for decoding one picture datum, TW is the time required for next writing of blocks into an optical disc, and TPO is the time required for next reading of blocks from the optical disc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing apparatus for performing recording processing and reproduction processing on a recordable optical disk such as DVD-RAM, DVD-R, DVD-RW.

[0002]

2. Description of the Related Art The above-described recording / reproducing apparatus is not only limited to the function of recording / reproducing an image but also has various additional functions, and is therefore a topic of market participants. One of the additional functions that the recording / playback device has is called "chase playback". With a general video tape recorder, for example, when recording a 2-hour long TV program,
The TV program cannot be played back until the recording is completed. On the other hand, in the chasing reproduction by the recording / reproducing apparatus, the reproduction process for the already recorded video and the recording process are performed in parallel while the TV program is continuously recorded. As a result, the user can start watching the TV program without waiting for the completion of the recording of the 2-hour TV program. In the following, how to perform chasing playback when a DVD is targeted will be described. Reading / writing from / to a DVD is performed using a VOBU (Video Object Unit) as a unit. A VOBU is a collection of picture data corresponding to a playback time of 0.4 to 1.0 seconds that composes a GOP and a DVD together with these.
It is one block consisting of audio data to be read from. Picture data is 1/33 second
This is the data that should be displayed during the display period of the TV signal.

On the other hand, a recording / reproducing apparatus for DVD includes a reproducing buffer, a recording buffer, an MPEG encoder, an MPEG decoder, and an access control section. The playback buffer stores the VOBU read from the DVD. The MPEG decoder sequentially decodes the picture data contained in the VOBU stored in the reproduction buffer and displays it for a display period of 1/33 seconds. The MPEG encoder creates a VOBU containing a picture data string with a time length of 0.4 to 1.0 seconds by encoding an input signal input from the outside of the device in the display period of 1/33 seconds, and records it in the recording buffer. I will store it in. The access control unit reads the VOBU from the DVD to the playback buffer (VOBU read) and the DVD from the recording buffer.
VOBU is written to (VOBU write).

Here, the speed of reading / writing DVD is MPEG.
The VOBU write and VOBU read are executed in a time division manner, which is much faster than the speed at which the encoder and the MPEG decoder perform the encoding and decoding processes. Time-division multiplexing of VOBU write-VOBU read enables chasing playback.

[0005]

By the way, there is a case where the operator orders the fast-forward during the execution of the chase reproduction. In fast-forwarding, the recording / playback apparatus does not decode all of the plurality of picture data forming the blocks stored in the playback buffer, but plays back only a part of the picture data. Therefore, in fast-forwarding, the picture data in the reproduction buffer is consumed in a short period of time. In order to supply sufficient picture data to the playback buffer during fast forward, VOBU read must be performed frequently. However, if the VOBU read is attempted at a high frequency, many conflicts will occur between the VOBU write and the VOBU read. In such a conflict, the VOBU write is given priority over the VOBU read, so it is not possible to obtain the VOBU to be decoded in the playback buffer when fast-forwarding, and the next VOBU
The playback buffer may underflow until a read is executed. If the playback buffer underflows, the playback is interrupted until the fast-forward VOBU read is completed for a moment, that is, "the playback is stopped for a moment and the playback is stopped". Such repetition is unsightly and may be a factor that reduces the user's impression of the recording / playback apparatus.
However, it may be possible to eliminate such playback interruptions by improving the read / write speed for DVDs. In fact, it is said that playback interruption cannot occur if fast-forwarding is achieved at a speed 10 times faster than the read / write speed of a DVD, as with a hard disk. However, improving the access speed to the medium requires discovering new materials and accumulating various researches and tests, and does not meet the demand for early commercialization of the recording / reproducing apparatus. It is understood that the only measure that can meet such demands is to devise so that playback interruption does not occur during fast-forwarding while considering the read / write speed limit for DVDs.

An object of the present invention is to provide a recording / reproducing apparatus capable of preventing interruption of reproduction even if fast-forward is instructed during chasing reproduction of an optical disk.

[0007]

The above-described object is to provide a reading means for time-divisionally performing a process of writing a block containing a plurality of picture data on an optical disc and a read process of a block already written, and a read block. Are sequentially stored to output the picture data included therein, a decoding means for decoding the output picture data, and a block in the reproduction buffer when the user instructs to perform fast forward. The recording / reproducing apparatus is provided with a control unit that selects N pieces of picture data satisfying the following (Equation 1) from the picture data to be output and outputs them to the reproduction buffer.

(Equation 1) N × Vf≈TP1 TP1 ≧ TP0 + TW Vf: Time required to decode one picture data TW: Time required to write the next block to the optical disc TP0: Required to read the next block from the optical disc time

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of a recording / playback apparatus will be described with reference to the drawings. FIG. 1 is a diagram showing an internal configuration of the recording / playback apparatus according to the present embodiment. As shown in FIG. 1, the recording / playback apparatus includes an MPEG encoder 1,
Recording data control unit 2, recording buffer 3, DVD 4, reproduction buffer 5, MPEG decoder 6, drive device 7, access control unit 8, recording / reproduction control unit 9, reproduction data control unit 10,
And a transfer control unit 11.

The MPEG encoder 1 includes a video encoder for obtaining a plurality of picture data by encoding a video signal input from the outside of the apparatus, and a plurality of audio data by encoding an audio signal input from the outside of the apparatus. An audio encoder to get
Equipped with a system encoder that obtains a VOBU consisting of GOP and audio data by interleaving multiple picture data and audio data corresponding to a playback time of 0.4 to 1.0 seconds, and stores the generated VOBUs in the recording buffer 3 in sequence. Do it. MPE each time one VOBU is output
The G encoder 1 has an ID for uniquely identifying the VOBU and a V
OBU data size (Size) and playback time (Time) of each VOBU
And are output to the recording / playback control unit 9.

FIG. 2 is a diagram in which the structure of the VOBU is detailed step by step. The video encoder sequentially encodes one frame (corresponding to 1/33 seconds) of the video signal input to the device. As a result, the picture data shown in the first row is generated. Picture data is compressed using the Bidirectionally Predictive (B) picture, which is compressed using the correlation with the images to be played in the past and future directions, and the correlation with the image to be played in the past direction. There are three types of Predictive (P) pictures and Intra (I) pictures that are compressed by using the spatial frequency characteristic in the image for one frame without using the correlation. Of a plurality of picture data, a group of pieces corresponding to a reproduction time of 0.4 to 1.0 seconds constitutes a GOP shown in the second row. The GOP unit picture data is divided into a plurality of 2 KByte units by the system encoder. On the other hand, the audio encoder generates an audio data string shown in the first stage by sequentially encoding audio signals input from outside the device. The system encoder, as shown in the third row of this audio data string, is about 2 KB.
Divide into yte units. System encoder is 2KByt
The GOP-unit picture data divided into e is interleave-multiplexed with the audio data sequence divided into about 2 KByte units to form the pack sequence shown in the fourth row. Such a pack row is composed of multiple VOBUs (Video Objec
t Unit) is formed. The VOB is obtained on the DVD by sequentially recording the VOB on the DVD. A VOB is a VOBU string consisting of picture data having the same video attribute and audio data having the same audio attribute. Further, the DVD 4 has a file system called UDF (Universal Disk Format), and the VOB is handled as one file.

The recorded data control unit 2 is an MPEG encoder 1
Is a device driver that controls the drive of the. The recording buffer 3 was obtained by the encoding of the MPEG encoder 1.
VOBUs are sequentially accumulated, and if the accumulated amount in the recording buffer 3 exceeds a predetermined threshold value, these are collectively output to the drive device for recording on a DVD. FIG. 3 shows an example of a timing chart inside the recording / playback apparatus. The first row in FIG. 3 shows the state transition in the recording buffer 3. As shown in this figure, the amount of data stored in the recording buffer 3 is determined by the MPEG encoder 1
It is composed of repeating monotonically increasing RP1 by sequentially accumulating picture data output from the recording buffer 3 and monotonically decreasing RP2 by sequentially outputting picture data from the recording buffer 3 to the drive device 7. The slope of the monotonous increase RP1 is proportional to the encoding speed Vin by the MPEG encoder 1, and the slope of the monotonous decrease RP2 is the speed difference between the output speed Vout from the recording buffer 3 to the drive device 7 and the encode speed Vin by the MPEG encoder 1. Proportional to (Vout-Vin).
The steeper monotone increase RP1 compared to the monotonic decrease RP2 is due to MPEG
The encoding speed of the encoder 1 is the recording buffer 3
Based on being faster than the output speed from.

The DVD 4 is a recordable optical disc in which a plurality of VOBUs stored in the recording buffer 3 are recorded. FIG. 4 shows the physical structure of the DVD 4. In the figure, the DVD 4 is composed of a plurality of sectors, and this sector row constitutes an ECC block in units of 16. This ECC block is a unit capable of error correction. For recording on the DVD 4, the VOBU is divided into a size within the data size of this ECC block (this division unit is called a segment), and is written in each ECC block. A plurality of VOBUs recorded on the DVD 4 constitutes a VOB.

At the time of recording on the DVD 4, the arrangement of the segments on the DVD 4 is not always continuous. This is DV
It is based on the fact that the drive device performs a recording process called a skip recording method when recording on D4. In the skip recording method, when a defective sector appears on the DVD 4, the segment is not recorded in the ECC block containing the defective sector, but the segment is recorded in the ECC block located next to the ECC block containing the defective sector. is there. VOBU
The segments that make up are arranged separately so as to avoid ECC blocks that include defective sectors. Therefore, the logical address of the setting where the segments that make up the VOBU are recorded,
Physical addresses are not contiguous. This is different from the alternative sector recording method in which if there is a defective sector, the logical address assigned to this defective sector is assigned to the alternative sector so that the logical addresses are continuous. DVD4 because the skip recording method is used
Therefore, it is impossible to specify the location of the segment by using the logical address. Only when the allocation information indicating the locations of the segments constituting the VOBU is created and recorded on the DVD 4, the location of the VOBU can be accurately grasped.
FIG. 5 is a diagram showing allocation information generated when a segment constituting a VOBU is recorded so as to avoid a defective sector. In this figure, the segment is the address
It is recorded in the ECC block of (adr1,2,3,4). It is understood that the address of the ECC block and the continuous length are shown in this allocation information. Since the VOB is recorded in the file as described above, the allocation information about each VOBU is realized as the file management information of the file system.

Until the completion of the allocation information generation, if the VOBU to be reproduced cannot be specified, the chasing reproduction will be hindered. This is because the VOBU to be reproduced cannot be specified until the allocation information is determined and read out, and the VOBU designation during the chasing reproduction is delayed. Therefore, in this embodiment, the VOBU to be reproduced in the chasing reproduction is specified by using the ID instead of the logical address and the physical address in the DVD 4,
We are working to speed up the designation of VOBUs to be played.

The reproduction buffer 5 is a buffer for storing a plurality of VOBUs collectively read from the DVD 4, and outputs picture data and audio data contained in these VOBUs to the MPEG decoder one by one. Go on.
The fourth row in FIG. 3 shows the state transition of the reproduction buffer 5.
As shown in this figure, the state transition of the reproduction buffer 5 is
Monotonically increasing by reading multiple VOBUs from RP3
And the monotonically decreasing RP4 due to the picture data included in the read VOBU being sequentially output. The slope of monotone decrease RP4 is based on the output speed Vout from the reproduction buffer 5 to the MPEG decoder, and the slope of monotone increase RP3 is DVD
4 from the input speed Vin to the playback buffer 5 and the output speed Vout from the playback buffer 5 to the MPEG decoder (Vin-V
out).

The MPEG decoder 6 includes a video decoder that decodes picture data to obtain a video signal, and an audio decoder that decodes audio data to obtain an audio signal. The drive device 7 is equipped with a spindle motor, an optical pickup, and an actuator.
Read and write to. In this reading and writing, the VOBU write for the VOBU stored in the recording buffer 3 and the VOBU read for the VOBU stored in the DVD 4 are performed in a time division manner. The second and third stages of Fig. 3 show VOBU
The figure shows how writing and VOBU reading are performed in a time division manner. VO
It can be seen that the BU write exists at the position of monotonically decreasing RP2 and the VOBU read exists at the position of monotonically increasing RP1. In this figure, the periods of VOBU write and VOBU read are drawn equally, but this is only for convenience of drawing, and it should be noted that the time required for VOBU write and VOBU read varies. . This is because the encoding by the MPEG encoder 1 is performed based on the compression encoding of the variable code length method. It should be noted that the VOBU write and VOBU read periods are different from each other, and thus the changes in the buffer states of the recording buffer 3 and the reproduction buffer 5 are also different.

The access control unit 8 is a device driver for controlling the drive of the drive device 7, and controls the drive device 7 to perform VOBU write and VOBU read. Since the plurality of VOBUs constituting the VOB are recorded as files on the DVD 4, the access control unit 8 implements VOBU write and VOBU read through the same procedure as for normal file access. That is, the access control unit 8
Opens the file before reading / writing VOBU,
Then, the allocation information is read. If the VOBU is written, the allocation information is updated with the writing of this VOBU. After updating the allocation information,
The allocation information updated up to that time is written back to the DVD 4 and the file is closed. VOBs that should be written to the DVD 4 in order for the access control unit 8 to perform write control
A write command Write (id, len) specifying the ID designating U and the data length Len of the VOBU may be issued. Further, in order to make the access control unit 8 control the reading of the VOBU from the DVD 4, an ID that uniquely specifies the read VOBU,
Read command Read (id, offset, which specifies the offset from the beginning of the VOB to the VOBU and the data length Len of the VOBU.
len).

The recording / playback control section 9 is an application program for performing integrated control of chasing playback by the recording / playback apparatus according to an instruction from the user. When the user instructs to start recording, the recording data control unit 2 is instructed to start encoding. Each time a new VOBU is generated by the encoding of the MPEG encoder 1, the recording / playback control unit 9 receives the playback time, size, and ID of the newly generated VOBU from the MPEG encoder 1, and based on this, receives time map information. Generate. The time map information is data indicating where the VOBU to which each ID is added exists in the VOB. By referring to this time map information, it is possible to know where each VOBU exists in the VOB. FIG. 6 is a diagram showing an example of time map information. As shown in this figure, the time map information is a combination of the serial number of the VOB and the serial number of the VOBU in that VOB (1-1,1-2,1-3,1-4,1-5 in the figure). , 1-6
...) to uniquely identify the VOBU included in each VOB
And the playback time of each VOBU (time1,2,3,4,5 ...
), And the data size of each VOBU (Size1,2,3,4,5 ...) Is shown in association with each other, and is recorded on the DVD as VOB management information.

By adding the sizes shown in this time map information, it is possible to obtain the offset to any VOBU in the VOB. Further, the recording / playback control unit 9
Is a pointer (R that uniquely identifies the VOBUs that have already been written to the DVD and already played, among the VOBUs that make up the VOB.
(ead pointer, Write pointer)
For example, from the te pointer, Write (id, len) for VOBUs in the range of 5 to 10 is issued to the access control unit 8, and Read is issued.
For example, Read (id, offset, len) for VOBUs in the range of 5 to 10 is issued to the access control unit 8 from the pointer. The issuance of these Write (id, len) and Read (id, offset, len) is performed according to the storage amounts of the recording buffer 3 and the reproduction buffer 5. FIG. 7 shows Read (id, offset, len), Write (id, le)
It is a figure which shows the issuing timing of n). The difference between this figure and FIG. 3 is that there is a Wr between the state transition of the recording buffer 3 in the first stage of FIG. 3 and the execution timing of the second VOBU write.
The issue timing of ite (id, len) is described in Fig. 3.
State transition of the reproduction buffer 5 in the third stage of
Read (id, offs
et, len) issuance timing is described.
According to this figure, issuance of Write (id, len) is required for recording buffer 3
It can be seen that the data size of the VOBU accumulated in the above is performed at the timings mw1, mw2, mw3, mw4 ... When the data size exceeds the threshold value SH1. Read (id, offset, len) is issued in playback buffer 5
It can be seen that the data size of the VOBU stored in the above is performed at the timings mr1, mr2, mr3, mr4 ..

The reproduction data control unit 10 instructs the MPEG decoder 6 to start decoding when reproduction is instructed. In this reproduction, the reproduction data control unit 10 controls the normal reproduction, the fast-forwarding, the chasing reproduction,
Different processing is performed in each case of fast-forwarding in chasing playback. First, at this time, the reproduction data control unit 10 issues the picture data stored in the reproduction buffer 5 to the MPEG decoder one by one. In the subsequent case, among the VOBUs stored in the playback buffer 5,
By issuing only the I picture and P picture to the MPEG decoder, the reproduction of the VOBU stored in the reproduction buffer 5 is performed in 1/2, 1/3 of the time compared with the normal reproduction. At this time, the period for consuming the VOBU stored in the playback buffer 5 is also 1/2 or 1/3, so it is very frequent.
The recording / playback control unit 9 is urged to request the issuance of Read (id, offset, len). In case of, Read (id, offse
(t, len) high frequency issuance is required, but VOBU read and VOBU
Read (id,
offset, len) cannot be issued. But Read (i
If d, offset, len) is not issued, an underflow of the reproduction buffer 5 occurs and display interruption occurs.

FIG. 8 is a timing chart showing the operation timing inside the recording / reproducing apparatus when the fast-forward is designated in the chase reproduction. In this figure, since the fast-forward is designated, the output speed Vout of the picture data from the reproduction buffer 5 becomes s times, and the monotonous decrease in the reproduction buffer 5 becomes s times. The rate of monotonic decrease is s
Since it has doubled, the time during which the picture data is being supplied from the reproduction buffer 5 to the MPEG decoder 6 is only hs.
, Hs2, hs3 ... And there are periods af1, af2, af3, ... In which the underflow of the reproduction buffer 5 occurs. However, if VOBU read can be executed at the points Rd1 and Rd2 immediately before the underflow of the playback buffer 5 occurs,
The underflow of the playback buffer 5 can be avoided, but the VOBU read during the period designated by Rd1 and Rd2 is VOBU.
VOBU read is impossible because it conflicts with write. VO
The time required for BU write is TW, the time required for VOBU read is
If TP0, during TW + TP0, DVD4 to playback buffer 5
The supply of VOBU to the company will be lost. Even if the VOBU supply may be interrupted, the reproduction data control unit 10 performs the following processing so that the reproduction is not interrupted. That is, the picture data contained in the VOBU contained in the reproduction buffer 5 is not fast-forwarded as it is, but N picture data whose total reproduction time is TP1 (TP1> TW + TP0) are selected and issued to the MPEG decoder. To do. The method of selecting N picture data is as follows. Considering the display period of picture data as 1/33 seconds, select N picture data of TP1≈1 / 33 seconds × N. The selected N picture data are M
The decoding process by the MPEG decoder is not interrupted while it is being issued to the PEG decoder, so that the reproduction process is not interrupted.

FIG. 9 shows MPE by selecting N picture data.
FIG. 7 is a diagram showing a state transition of the reproduction buffer 5 when a process of issuing to the G decoder 6 is performed. For comparison, in this figure, the monotonic decrease during normal reproduction and the monotonic decrease during fast forward are indicated by broken lines, and the state transition of the reproduction buffer 5 when N picture data is selected and issued to the MPEG decoder 6 is indicated by solid lines. Shows. In this figure, underflow of the playback buffer 5 does not occur during the period when VOBU write and VOBU read are being performed, so an operation such as "fast-forward is performed for a moment and playback is interrupted" is performed. There is no.

How to determine TW and TP0 when deriving TP1 will be described. Since the encoding by the MPEG encoder 1 is based on the variable length coding method based on the inter-frame correlation, the VOBU data sizes are different from each other.
Playback data control unit 1 to predict TW closer to the actual measured value
0 is the total data size of the VOBU stored in the recording buffer 3, the position where the VOBU should be written on the DVD 4, the VOBU
It is detected based on three parameters of the time when Write (id, len) for writing is issued, and TW is predicted based on these. FIG. 10 is a diagram showing how TW prediction is performed. As shown in FIG. 10A, when the VOBU write is not executed in the period in which the fast-forward is instructed, the TW is predicted from the remaining parameters without considering the time when the Write (id, len) is issued. As shown in FIG. 10B, when the VOBU write is executed at the time when the fast-forward is instructed, the offset Offset1 has passed from the time when the Write (id, len) is issued to the time when the fast-forward is instructed. Therefore, the time obtained by subtracting this offset Offset1 from the period required for VOBU writing is TW. How a reproduction data control unit 10 selects N picture data when a plurality of VOBUs are accumulated in the recording buffer 3 and the reproduction buffer 5 will be described below. This operation example assumes an initial state as shown in FIG. In this initial state, VOBU # 81 to # 85 are accumulated in the recording buffer 3 and VOBU # 11 to # 15 are accumulated in the reproducing buffer 5, and VOBU # 16 to # 20 are designated as Read (16, offset, len) to Read ( 20, offset, len) is about to be issued. If fast-forward is instructed in this state, the data size of the VOBUs # 81 to # 85 stored in the recording buffer 3 as shown in FIG.
TW is predicted from the position Wptr of the DVD 4 to which is written. Similarly, the data size of VOBU # 16 to # 20, VOBU
Predict TP0 from the position Rptr where # 16 to # 20 are read,
0, TP1 is derived from TW. When multiple picture data (I picture, P picture, B picture) exist in VOBU # 11 to # 15, all of these picture data are set to 1/33 seconds,
Select N picture data that satisfies TP1 ≈ 1/33 second × N,
Issue the selected N picture data to the MPEG decoder. VOBU # 81- # 85 are written to DVD4, VOBU # 16- # 20
Even during the period when is read from the DVD 4, the picture data is supplied to the MPEG decoder without interruption, so that the display is not interrupted.

The transfer control unit 11 uses Read (id, offset, len)
The allocation information about the VOBU specified in
If it does not exist in D4 and the VOBU write for the VOBU to be read is incomplete, it is stored in the recording buffer 3.
The VOBU is transferred and directly stored in the reproduction buffer 5. By directly supplying the VOBU from the recording buffer 3 to the reproduction buffer 5, the chasing reproduction can be continued even when the VOBU to be reproduced and the VOBU to be written are close to each other. 13 to 16 show VO by the transfer control unit 11.
It is explanatory drawing which shows how BU transfer is performed.
As shown in the figure, VOBU # 81 to # 85 are stored in the reproduction buffer 5, and the recording / reproduction control unit 9 issues Read (81, offset, len) specifying VOBU # 81 as the VOBU to be read. And Since VOBU # 81 is not stored on the DVD,
The VOBU is supplied by transferring the VOBU # 81 stored in the recording buffer 3 to the reproduction buffer 5 as indicated by the arrow y81. Similarly, the VOBU # 82 is transferred from the recording buffer 3 to the reproduction buffer 5 as indicated by an arrow y82 in FIG.
Then, the VOBU # 83 is supplied from the recording buffer 3 to the reproduction buffer 5 as indicated by the arrow y83 in FIG. This
Even if a VOBU whose writing to the DVD 4 has not been completed is designated as a reproduction target, this VOBU can be supplied to the reproduction buffer 5.

The processing procedure of the recording / playback apparatus configured as described above will be described with reference to a flowchart. Figure 1
7 is a flowchart showing a processing procedure when the recording / playback apparatus performs VOBU writing, and FIG.
It is a flow chart which shows a processing procedure at the time of performing VOBU read. The VOBU write consists of pre-processing, loop processing, and post-processing. In the pre-processing, it is judged whether or not the file on the DVD 4 is opened (step S1). It is to acquire (step S2).

The loop processing waits for the amount of accumulation in the recording buffer 3 to exceed the threshold value SH1 (step S3), and if it exceeds, the MPEG decoder 6 issues a write command (step S4), and the access control unit 8 VOBU to DVD
4 (step S5) and updating the allocation information (step S6) is repeated until the accumulated amount in the recording buffer 3 falls below the threshold value SH2 (step S7). Post-processing is a file close request by the MPEG decoder 6 (step S8)
And the allocation information DVD by the access control unit 8
4 (step S9).

The VOBU read processing procedure shown in FIG.
Like BU writing, it consists of pre-processing, loop processing, and post-processing.
Only this loop processing is different from VOBU read. Read (id, offset, len) is issued in the loop processing (step S1
1) It is determined whether the ID designated by this Read (id, offset, len) exists in the allocation information (step S12). DVD4 to playback buffer 5 if present
The VOBU is read from the recording buffer 3 to the reproduction buffer 5 if it does not exist (step S13).
Is transferred (step S14). VO in playback buffer 5
After BU is read, it is determined whether or not fast-forward is designated (step S15). When fast-forward is designated, N picture data satisfying the playback time TP1 is selected from the playback buffer 5. To the MPEG decoder 6 (step S16), and if fast forward is not specified,
Each picture data in the reproduction buffer 5 is converted into an MPEG decoder 6
(Step S17). The loop processing described above (step S11 to step S17) is repeated as long as the reproduction is continued (step S10).

As described above, according to this embodiment, the playback time satisfying the relationship of TP1 ≧ TP0 + TW when the fast forward is designated.
Since N pieces of picture data having TP1 are selected from the reproduction buffer 5 and issued to the MPEG decoder, underflow of the reproduction buffer 5 does not occur. Although the above description has been given based on the embodiment, it is merely presented as an example of a system in which the best effect can be expected in the present situation. The present invention can be modified and implemented without departing from the gist thereof. As typical modified embodiments, the following (A) and (B)
(C) ...

(A) In the present embodiment, the VOB has the video stream and the audio data string multiplexed, but sub-picture data obtained by run-length compression of subtitle characters may be multiplexed. (B) The procedure described in the present embodiment (flowcharts in FIGS. 17 and 18) and the like may be realized by a program, and the program may be recorded in a recording medium for distribution / sales. Such recording media include IC cards, optical disks, floppy (registered trademark) disks, and the like. The programs recorded in these are provided for use by being installed in a general-purpose computer. This general-purpose computer sequentially executes the installed programs to realize the functions of the recording / playback apparatus shown in this embodiment.

(C) In the embodiment, the read / write unit is VO.
Although it is set to BU, other units may be used. Further, although the VOB obtained by multiplexing the video stream and the audio data string is targeted for partial deletion, the VOB may include only the video stream. Furthermore, the video stream to be multiplexed with the video object is MPEG2.
Although the compression coding is based on the standard, it may be compressed by another compression coding method as long as the compression coding method is based on the correlation with other picture data.

[0032]

EFFECTS OF THE INVENTION According to “Claim 1”, N picture data corresponding to the reproduction time TP1 among a plurality of picture data stored in the reproduction buffer are issued to the MPEG decoder. This TP1 is longer than the sum of TP0 and TW, and underflow of the reproduction buffer can be avoided as long as the picture data corresponding to the reproduction time of TP1 is reproduced.

As described above, the recording / reproducing apparatus according to the present invention comprises a reading means for time-divisionally performing a process of writing a block containing a plurality of picture data on an optical disc and a process of reading the already written block, A playback buffer that sequentially stores the read blocks and outputs the picture data included therein, a decoding unit that decodes the output picture data, and a playback buffer if the user instructs to perform fast-forwarding. Control unit that selects N pieces of picture data that satisfy the following (Equation 1) from the picture data that make up the blocks in the block and outputs them to the playback buffer. It is compressed based on the encoding method, and even if the data size of each block is different from each other, it will be more measured. Can predict near TW.

Since the control means predicts the time TW based on the data size of the block to be written and the position on the optical disc to which the block is to be written, the block is compressed based on the variable length coding method based on the interframe correlation. Even if the data sizes of the blocks are different from each other, it is possible to predict Tw that is closer to the actual measurement value.

Since the recording / reproducing apparatus further comprises a transfer means for transferring the blocks stored in the recording buffer to the reproducing buffer when all the blocks stored in the optical disk are read out to the reproducing buffer. Even if the reading from the optical disk catches up with the writing to the optical disk in the chasing reproduction, the block can be supplied to the reproduction buffer.

On the optical disc, location information indicating the location of each block is recorded in association with an identifier for each block, and the recording / playback apparatus generates an identifier for designating a block to be decoded. The reading means reads out from the optical disc based on the location information a block designated by the identifier generated by the generation means and having corresponding location information recorded on the optical disc, and the transfer means , A block designated by the identifier generated by the generation means, in which corresponding location information is not recorded on the optical disc, is taken out from the recording buffer, transferred, and stored in the reproduction buffer, so that it is written on the optical disc. Or
Blocks are uniformly specified using identifiers regardless of whether they are stored in the recording buffer. Therefore, even if the logical address and physical address on the optical disk are not fixed, blocks that should be played sequentially are specified. It is possible to specify the block to be read without delay.

[Brief description of drawings]

FIG. 1 is a diagram showing an internal configuration of a recording / playback apparatus according to an embodiment.

FIG. 2 is a diagram in which the structure of a VOBU is detailed step by step.

FIG. 3 is a diagram showing an example of a timing chart inside the recording / playback apparatus.

FIG. 4 is a diagram showing a physical structure of a DVD 4.

FIG. 5 is a diagram showing an example of allocation information generated when a segment constituting a VOBU is recorded so as to avoid a defective sector.

FIG. 6 is a diagram showing an example of time map information.

FIG. 7 is a diagram showing the timing of issuing Read (id, offset, len) and Write (id, len).

FIG. 8 is a timing chart showing the operation timing inside the recording / playback apparatus when fast-forwarding is designated in the chase playback.

FIG. 9 is a diagram showing a state transition of the reproduction buffer 5 when a process of selecting N picture data and issuing it to the MPEG decoder 6 is performed.

10 (a) and 10 (b) are diagrams showing how TW prediction is performed.

[FIG. 11] VOBU # 81 to # 85 are accumulated in the recording buffer 3, VOBU # 11 to # 15 are accumulated in the reproduction buffer 5, and VOBU # 16 to # 20 are designated as Read (16, offset, len) to Read ( 20 is a diagram showing an initial state in which (20, offset, len) is about to be issued.

FIG. 12 is a diagram showing an operation example when selecting N pieces of picture data in the state of FIG. 11;

FIG. 13 is an explanatory diagram showing how VOBU transfer is performed by the transfer control unit 11.

FIG. 14 is an explanatory diagram showing how a VOBU is transferred by the transfer control unit 11.

FIG. 15 is an explanatory diagram showing how a VOBU is transferred by the transfer control unit 11.

FIG. 16 is an explanatory diagram showing how VOBUs are transferred by the transfer control unit 11.

FIG. 17 is a flowchart showing a processing procedure when the recording / playback apparatus performs VOBU writing.

FIG. 18 is a flowchart showing a processing procedure when the recording / playback apparatus performs VOBU read.

[Explanation of symbols]

1 MPEG encoder 2 Recording data control unit 3 recording buffer 4 DVD 5 playback buffer 6 MPEG decoder 7 Drive device 8 access control unit 9 Recording / playback control section 10 Playback data control unit 11 Transfer control unit

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5C052 AA02 AB04 AC01 CC11 CC12                       DD04                 5C053 FA24 GB07 GB11 GB15 GB37                       HA21 JA01 JA21 KA04                 5D044 AB05 AB07 BC06 CC04 DE12                       EF02 FG10 HH05

Claims (13)

[Claims] 1. A reading means for time-divisionally executing a process of writing a block including a plurality of picture data on an optical disc and a process of reading a block already written, and sequentially storing the read blocks in these. A playback buffer that outputs the included picture data, a decoding unit that decodes the output picture data, and, if the user instructs to perform fast forward, from the picture data that configures the blocks in the playback buffer,
A recording / reproducing apparatus comprising: a control unit that selects N pieces of picture data that satisfy the following (Equation 1) and outputs the selected N pieces of picture data to a reproduction buffer. (Equation 1) N × Vf≈TP1 TP1 ≧ TP0 + TW Vf: Time required to decode one picture data TW: Time required to write the next block to the optical disc TP0: Time required to read the next block from the optical disc 2. The recording / reproducing apparatus according to claim 1, wherein the control unit predicts the time TW based on the data size of the block to be written and the position on the optical disc to which the block is to be written. 3. The control unit predicts the time TW in consideration of the difference between the time when writing to the optical disk should be started and the time when the fast speed is instructed. Recording and playback device. 4. The recording / reproducing according to claim 1, wherein the control unit predicts the time TP0 based on a data size of a block to be read and a position on the optical disk to read the block. apparatus. 5. The recording / playback apparatus further includes an encoder for obtaining blocks by sequentially encoding an input signal input from the outside of the apparatus, and a block obtained by the encoder to be written on an optical disk. 5. The recording / reproducing apparatus according to claim 1, further comprising a recording buffer for storing, wherein the reading unit sequentially writes the blocks accumulated in the recording buffer onto an optical disc. 6. The recording / reproducing apparatus further comprises a transfer means for transferring the blocks stored in the recording buffer and storing the blocks in the reproducing buffer when all the blocks stored in the optical disk are read out to the reproducing buffer. The recording / playback apparatus according to claim 5, wherein 7. The optical disc stores location information indicating the location of each block in association with an identifier for each block, and the recording / playback apparatus generates an identifier for designating a block to be decoded. The reading means reads a block, which is designated by the identifier generated by the generating means and has corresponding location information recorded on the optical disc, from the optical disc based on the location information, and transfers the block. The means takes out a block designated by the identifier generated by the generation means, in which corresponding location information is not recorded on the optical disc, from the recording buffer, and transfers the block.
7. The recording / reproducing apparatus according to claim 6, wherein the recording / reproducing apparatus stores it in a reproduction buffer. 8. A reading means for time-divisionally performing a process of writing a block including a plurality of picture data on an optical disc and a process of reading a block already written, and the read block is sequentially stored and stored in them. A computer-readable recording medium in which a program is recorded in a computer-readable format that includes a reproduction buffer that outputs included picture data and a decoding unit that decodes the output picture data. When instructed by the user, from the picture data forming the blocks in the playback buffer,
A computer-readable recording medium on which is recorded a program that causes a computer to perform a control step of selecting N pieces of picture data that satisfy the following (Equation 1) and outputting to the reproduction buffer. (Equation 1) N × Vf≈TP1 TP1 ≧ TP0 + TW Vf: Time required to decode one picture data TW: Time required to write the next block to the optical disc TP0: Time required to read the next block from the optical disc 9. The computer-readable recording medium further comprises a transfer for transferring the blocks stored in the recording buffer and storing the blocks in the reproduction buffer when all the blocks stored in the optical disc are read in the reproduction buffer. The computer-readable recording medium according to claim 8, wherein a program for causing a computer to perform the steps is recorded. 10. Location information indicating the location of each block is recorded on the optical disc in association with an identifier for each block, and the recording program generates an identifier for designating a block to be decoded. The reading means includes a block designated by the identifier generated in the generating step, in which corresponding location information is recorded on the optical disc, is read from the optical disc based on the location information, and the transferring step is provided. Is a block designated by the identifier generated in the generating step, in which corresponding location information is not recorded on the optical disc is taken out from the recording buffer, transferred, and stored in the reproduction buffer. Item 9
The computer-readable recording medium described above. 11. A reading means for time-divisionally performing a process of writing a block containing a plurality of picture data on an optical disc and a process of reading the already written block, and the read blocks are sequentially stored and stored in them. A computer-executable program that includes a playback buffer that outputs the included picture data and a decoding unit that decodes the output picture data. If the user instructs to perform fast-forward, the program in the playback buffer From the picture data that makes up a block,
A program for causing a computer to execute a control step of selecting N pieces of picture data that satisfy the following (Equation 1) and outputting them to a reproduction buffer. (Equation 1) N × Vf≈TP1 TP1 ≧ TP0 + TW Vf: Time required to decode one picture data TW: Time required to write the next block to the optical disc TP0: Time required to read the next block from the optical disc 12. The program further causes the computer to perform a transfer step of transferring the blocks stored in the recording buffer and storing the blocks in the reproduction buffer when all the blocks stored in the optical disk are read out to the reproduction buffer. 12. The program according to claim 11, wherein the program is recorded. 13. The optical disc stores location information indicating the location of each block in association with an identifier for each block, and the program generates an identifier that specifies a block to be decoded. The reading means reads a block designated by the identifier generated in the generating step, in which corresponding location information is recorded on the optical disc from the optical disc based on the location information, and the transferring step The block specified by the identifier generated in the generating step, in which the corresponding location information is not recorded on the optical disc is taken out from the recording buffer, transferred, and stored in the reproduction buffer. 1
The program described in 2.