JPH11144378A - Post-recording method for digital recording medium and device therefor, and reproducing method for the same and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a post-recording method capable of reproducing a post- recording sound by accurately matching it with the time of an original video. SOLUTION: This method comprises a first step of reading original data including at least a video bit stream from a digital recording medium 1, a second step of decoding this original data, a third step of encoding audio data to generate a new audio bit stream in synchronization with the decoding of this original data and a fourth step of writing this new audio bit stream in an area corresponding to a time roughly equal to the original data recording area of the digital recording medium 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method and apparatus for performing after-recording on video data and the like recorded on a digital recording medium.

[0002]

2. Description of the Related Art After-recording (hereinafter, also simply referred to as "after-recording") involves recording original data (only video data or audio data such as video data and dialogue) in studio recording or outdoor recording, and then editing the data. This is an audio editing processing method in which new audio data such as sound effects (after-recording audio data) are added and recorded in the process, or a part of the original audio data is replaced with such after-recording audio data.

There are several methods for dubbing original data recorded on a digital recording medium, for example, the following (1) to (3). The description will be directed to the methods (1) and (3) among them.

(1) After-record audio is input while reproducing the original data, and the after-record audio data is multiplexed with the original data in real time when the original data is reproduced, and is recorded on the digital recording medium.

(2) The dubbed audio data input while reproducing the original data is once recorded on another recording medium, and thereafter (ie, not in real time), the dubbed audio data reproduced from this other recording medium is It is multiplexed and recorded on a digital recording medium on which original data is recorded.

(3) After-recording audio data is recorded on the digital recording medium without being multiplexed with the original data, and during reproduction, the original audio data read from the digital recording medium and the after-recording audio data are mixed. And output it as a completed sound.

FIG. 5 shows an example of recording data (bit stream) on a digital recording medium. A video bit stream V, a main audio bit stream A1, and a sub audio bit stream A2 are multiplexed and recorded in one stream. Since the bit rate of the audio bit stream is lower than the bit rate of the video bit stream (for example, the former is about 6 Mbps or 8 Mbps, while the latter is about 256 kbps, the ratio is about 25: 1 or 32: 1. ), While most of the recording area is occupied by V, the recording areas of A1 and A2 are periodically scattered.

[0008] For example, MPEG2 is used as an encoding standard for digital recording media.
A video bit stream V compressed and encoded with MPEG2 video, and a main audio bit stream A1 and a sub audio bit stream A2 compressed and encoded with MPEG2 audio are recorded in a packet multiplexing system by the MPEG2 system. .

FIG. 6 shows an example of a processing procedure when performing post-recording by the method (1) on original data recorded on a digital recording medium as shown in FIG. First, a video bit stream V which is original data
And the main audio bit stream A1 are read from a digital recording medium, demodulated and error-corrected by an RF and demodulation circuit 21, and an ECC circuit 22, and then a buffer 23 for absorbing a difference between a read rate and a decode processing rate. (Including a demultiplex unit for demultiplexing, a video decoder and an audio decoder) 24
Video output terminal P1 and audio output terminal P2
And sends it to a display and a speaker (not shown) to reproduce the original video and audio.

[0010] A user who intends to perform post-recording, while reproducing video and audio in this manner, selects post-recording audio data (for example, audio data generated in front of a microphone not shown or library tape of post-recording audio). Reproduced audio data, etc.) are input from the audio input terminal P3. As the post-record audio data to be actually recorded, the input post-record audio data obtained by mixing the original (main voice) audio data with the mixer 25 is often used.

The dubbing audio data is encoded by the encoder 26 in synchronization with the reproduction of the original video and audio data, and is passed through the buffer 27 for absorbing the difference between the encoding processing rate and the writing rate.
8. After the error correction code is added and modulated by the modulation and RF circuit 29, the post-record audio data is written in the recording area of the sub-audio bit stream A2.

Since the recording area of the sub audio bit stream A2 only needs to have a capacity for recording the post-recording audio data, it is not necessary to record the audio data before the post-recording is performed. It may be. However, the sub audio bit stream A which is blank
When writing post-record audio data to the recording area of No. 2,
Video bitstream V and main audio bitstream A
1 and the sub audio bit stream A2 are correct (MPEG
If the bit stream does not become a multiplexed bit stream (according to the standards of the second system), it is necessary to perform the multiplexing again after the recording.

With the above, dubbing is completed. When reproducing the video and audio as a completed work from the digital recording medium that has been dubbed in this way, any of the original audio (main audio bit stream A1) and the dubbed audio (sub audio bit stream A2) can be used. Can be selected for playback.

In the above processing example, for the sake of convenience, description has been made assuming that only post-recording audio data is written. However, in practice, it is necessary to rewrite original data in addition to writing post-recording audio data because the ECC circuit performs processing in units of data blocks of a fixed size. That is, for example, if the size of the packet of the audio bit stream is 2 kbytes and the size of the data block of the ECC circuit is 32 kbytes or 64 kbytes,
The addition of the error correction code in the CC circuit 28 is performed by combining the after-recording audio data and the video bit stream V and the like recorded in the area adjacent to the recording area of the sub audio bit stream A2 in which the audio data is to be written. Alternatively, it must be performed in units of 64 kbytes of data. As described above, when new data is written in a partial area of the digital recording medium, data in an area adjacent to the new data is also a target to which the error correction code should be re-added, so that the original data needs to be rewritten. .

[0015]

By the way, in the post-recording that goes through such processing steps, each circuit generally performs the following steps from reading the video bit stream V and the main audio bit stream A1 to writing the post-record audio data. Long processing time.

ECC circuits 22, 28: tens of milliseconds each Buffer 23, 27: tens of milliseconds to tens of seconds (depending on the function of buffer used) Decoder 24: tens of milliseconds Seconds Encoder 26: Several tens of milliseconds

Therefore, since it takes a total of several hundred milliseconds to several seconds (in some cases, several tens of seconds) of processing time, the post-recording audio data is larger than the area in which the original data to be reproduced simultaneously is recorded. There has been a delay problem that data is written in an area corresponding to the reproduction time delayed by the processing time. That is, for example, in the case of packet multiplexing, the post-record audio data is recorded as a packet having a time stamp indicating a time later than the time indicated by the time stamp in the packet of the original data to be reproduced simultaneously.

Moreover, since the length of the processing time usually slightly changes each time after-recording is performed, the temporal relationship between the recording area of the original data and the recording area of after-recording audio data also changes each time after-recording is performed. Would. As a result, it has been difficult in the past to reproduce the dubbed audio exactly in time with the original video when reproducing the video and audio as a completed work.

The present invention has been made in view of the above points, and even after the processing steps shown in FIG. 6 employing the above-mentioned (1) post-recording method, the post-record audio can be easily and temporally combined with the original video and the like. It is an object of the present invention to provide an after-recording method and apparatus which can be reproduced in a manner that exactly matches the video.

Further, even if the after-recording method of (3) is adopted, the after-recording method and apparatus, and the reproducing method and apparatus, which can reproduce the post-recording audio accurately and temporally in agreement with the original video or the like. It is intended to provide.

[0021]

According to a first aspect of the present invention, there is provided an audio dubbing method, comprising: a first step of reading a bit stream from a digital recording medium; a second step of decoding the bit stream; In synchronization with the decoding of this bit stream, new data is encoded to be a bit stream for post-recording.
And a fourth step of writing the post-recording bit stream to a predetermined area of the digital recording medium.

According to this post-recording method, a post-record bit stream obtained by encoding new data in synchronization with decoding of a bit stream read from a digital recording medium is written to a predetermined area of the digital recording medium. Like that.

As described above, by writing the after-recording data in the predetermined area, the temporal relationship between the after-recording data recording area and the original data recording area becomes clear. As a result, when reproducing the video and audio as a completed work, it is possible to easily reproduce the post-recording data in time and exactly with the original data.

According to a ninth aspect of the present invention, there is provided an after-recording apparatus, comprising: a reading means for reading a bit stream from a digital recording medium; a decoder for decoding the bit stream; An encoder for recording a bit stream for recording, a writing unit for writing the bit stream for after recording to a digital recording medium, and an after recording for encoding encoded by the encoder in synchronization with the decoding of the bit stream by the decoder. Control means for controlling the writing means to write the bit stream into a predetermined area of the digital recording medium.

According to this after-recording apparatus, when new data is encoded by the encoder and a bit stream for after-recording is obtained in synchronization with the decoding by the decoder of the bit stream read from the digital recording medium by the reading means, The bit stream for dubbing is written into a predetermined area of the digital recording medium by the writing means under the control of the control means.

As described above, by writing the after-recording data in the predetermined area, the temporal relationship between the after-recording data recording area and the original data recording area becomes clear. As a result, when reproducing the video and audio as a completed work, it is possible to easily reproduce the post-recording data in time and exactly with the original data.

The post-recording method and apparatus according to claims 8 and 14 and the reproducing method and apparatus according to claims 15 and 18 are suitable for the above-mentioned post-recording method (3). It is an example of an apparatus.

According to the post-recording method and apparatus, information indicating a temporal correspondence between the original data and the post-recording data is recorded in the recording area of the additional information of the digital recording medium. Despite being recorded without multiplexing, based on this information, it is possible to reproduce the dubbed data exactly in time with the original data.

According to the reproducing method and apparatus, information indicating a temporal correspondence between the original data and the post-recording data is read from the recording area of the additional information of the digital recording medium. Data and post-record data are read out and decoded synchronously, so that even if the original data and post-record data are recorded without multiplexing during post-recording, the post-record data exactly matches the original data in time. It will be played.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, when the method (1) of the above-mentioned post-recording methods (1) to (3) is adopted (that is, after-recording sound is inputted while reproducing original data, An example of the present invention in a case where data is multiplexed with original data in real time when the original data is reproduced and recorded on the digital recording medium) will be described.

When the post-recording method of (1) is adopted, what kind of area is specifically determined as a "predetermined area" of the digital recording medium for recording the post-recording audio data is as follows. A) or (B)
Such a region is considered. However, these are preferred examples, and are not intended to exclude other areas.

(A) A region corresponding to a reproduction time substantially equal to the recording region of the original data This is an example determined according to a restriction on a multiplexing system such as an MPEG system. 5 and 6
If this area is described in relation to the following, it is a recording area of the sub audio bit stream A2 that is reproduced almost simultaneously with the main audio bit stream A1 read out in the processing process of FIG. (I) to (ii).

(I) The sub audio bit stream A which is spatially closest to the recording area of the main audio bit stream A1
Recording area No. 2 (ii) Sub-audio to which time information indicating the same time as the time information (presentation time stamp (PTS) in a packet in an MPEG system) added to this main audio bit stream A1 is added. Recording area of bit stream A2

(B) Area corresponding to a time greatly delayed from the recording area of the original data This is an example in which the determination is made without following the restrictions on the system in the multiplex system.

When writing post-recording data in the area (A), a data channel for reading original data from a digital recording medium and a data channel for writing post-recording data to the digital recording medium. And are required separately. Therefore, either a method of providing two systems of heads for reading and writing and performing reading and writing independently, or a method of performing reading and writing in a time-division manner by seeking one system of heads (It is needless to say that the latter method is limited to the case where the after-recording is performed on original data recorded on a random-access recording medium such as a disk).

Such a method is generally the same as a method of performing data input / output in a multi-channel in a recording / reproducing apparatus. However, even when the number of channels is only two and reading and writing are performed independently, only two heads are required. Even when reading and writing are performed in a time-division manner, the distance according to the magnitude of the delay is required. Since only the seek is required for the head (there is no case where a full stroke seek is performed), the seek distance is relatively small. Therefore, it can be said that the conditions for realization are less severe than in a general multi-channel.

On the other hand, when writing post-recording data in the area (B), after reading the original data with one head, the post-recording data is written at the current position of the head. I just need to go. Therefore, in terms of reducing the number of head systems and simplifying the control of the head, it can be said that this is easier to realize.

However, in this case, when reproducing the video and audio as a completed work, it is necessary to perform processing for reproducing the post-record data in time with the original data. This process is complicated particularly during special reproduction such as slow reproduction and double speed reproduction. Performing such processing also leads to an increase in the cost of the apparatus. Therefore, from these points, it can be said that it is more desirable to write data in the area (A). Therefore, a specific example will be described below by taking the case of writing in the area (A) as an example.

FIG. 1 shows an example of the system configuration of an optical disk apparatus to which the after-recording method and apparatus of the present invention are applied when the above-mentioned after-recording method (1) is employed. In this optical disk apparatus, one system of optical pickup (optical head) 2 is provided for one rewritable optical disk 1, and this optical pickup 2 is shared for both reading and writing of data. On the optical disc 1,
In the same manner as shown in FIG. 5, a video bit stream V, a main audio bit stream A1, and a sub audio bit stream A2 are recorded in a packet multiplexing system by the MPEG2 system. In each bitstream V, A1 and A2, one for each packet
In one ratio, there are packets with a presentation timestamp.

The bit stream read from the optical disk 1 by the optical pickup 2 is converted into an RF and demodulation / modulation circuit 3 (which has the functions of the RF and demodulation circuit 21 and the modulation and RF circuit 29 in FIG. 6), ECC Circuit 4 (FIG. 6)
Having the functions of the ECC circuit 22 and the ECC circuit 28), demodulation and error correction are performed respectively, and then, through the switch 5, for the read channel for absorbing the difference between the read rate and the decode processing rate. The data is sent to the buffer 6.

The bit stream extracted from the read channel buffer 6 is decoded by a decoder (including a demultiplex unit, a video decoder, and an audio decoder) 7 and supplied from a video output terminal P1 and an audio output terminal P2 to a display (not shown). , Are sent to the speaker and reproduced, while being sent to the bypass buffer 8. The bypass buffer 8 plays a role of accumulating the bit stream read from the optical disc 1 even after the decoding process and writing the bit stream to the optical disc 1 again.

The bit stream extracted from the bypass buffer 8 passes through a detector 9 for detecting the type of media (video, main audio, sub audio) of the packet based on the stream ID in each packet. Switch 1
0 is sent to one fixed contact.

On the other hand, the audio data input from the audio input terminal P 3 is encoded by the encoder 11 and then stored in the encoder buffer 12. The audio data extracted from the encoder buffer 12 is sent to the other fixed contact of the switch 10.

The movable contact of the switch 10 is connected to a write channel buffer 13 for absorbing the difference between the encode processing rate and the write rate. The data (the bit stream extracted from the bypass buffer 8 or the audio data extracted from the encoder buffer 12) sent to the write channel buffer 13 via the switch 10 is stored in the write channel buffer 1.
3 and the ECC circuit 4 via the switch 5
After the error correction code is added and modulated by the RF and demodulation / modulation circuit 3, it is written on the optical disk 1 by the optical pickup 2.

As an example, the read rate and the write rate are equal to each other (or both the read rate and the write rate are variable and their maximum rates are equal to each other). .

In this optical disk apparatus, the reason described above with reference to FIG. 6 is used after the bit stream is read from the optical disk 1 until the input audio data is written to the optical disk 1 in synchronization with the reproduction. Therefore, it takes several hundred milliseconds to several seconds.

Therefore, during the period from the reading to the writing, the position of the optical pickup 2 with respect to the optical disk 1 is advanced by this processing time.
In other words, considering a certain time as a reference, the position W where the optical pickup 2 must be present in order to write data in an area corresponding to a reproduction time substantially equal to the recording area of the read data is shown in FIG. As shown in (2), it is behind the read position R of the optical pickup 2 at the time by this processing time.

Returning to FIG. 1, the system controller 14
Is used to control the operation of each part of the optical disc device during post-recording as described later.
And R which stores a processing program to be executed by the CPU, etc.
It includes an OM and a RAM for temporarily storing data and the like generated during the processing. In this control, the fine adjustment of the position of the optical pickup 2 is performed by the detection of the address detection circuit 15 which takes in the bit stream demodulated by the RF and demodulation / modulation circuit 3 and detects the address information of the data currently being read. This is done based on the results. The switching control of the switch 10 is performed based on the detection result of the detector 9.

Next, an example of the processing executed by the system controller 14 during post-recording will be described. [First Step] First, the user specifies the original data to be post-recorded by operating the operation panel (not shown), or reads out the specification information of the original data to be post-recorded previously written on the optical disc 1. Then, of the original data recorded on the optical disk 1, the range of the original data to be post-recorded is determined.

Subsequently, the optical pickup 2 is caused to seek to the read start position X0 based on the address information of the original data to be post-recorded. Then, the optical pickup 2, the RF and demodulation / modulation circuit 3, and the ECC circuit 4 are set to the read mode, and the switch 5 is switched to the read channel buffer 6 to finely adjust the position of the optical pickup 2. Starts reading. As a result, the original data to be post-recorded is accumulated in the read channel buffer 6.

FIG. 3 shows the relationship between the position of the optical pickup 2 and the read / write status at each time during the after-recording operation (FIG. 3A), and the read channel buffer 6 and the write channel buffer 13 at these times. Are shown in FIG. FIG. 3A
In the figure, a thick solid line indicates that reading is being performed, a broken line indicates that writing is being performed, and a thin solid line indicates that seeking is being performed.

In FIG. 3, the accumulation processing in the read channel buffer 6 corresponds to the stage from time T0 to T2, and FIG. 3 also shows that the data accumulation amount of the read channel buffer 6 increases. Is appearing.

[Second Step] Original data is taken out from the read channel buffer 6, decoded and reproduced by the decoder 7, and stored in the bypass buffer 8.

The decoding process in the decoder 7 is continued until the end of post-recording regardless of the position of the optical pickup 2 and regardless of the read mode or the write mode. This decoding process is started between time T0 and time T1 in relation to FIG.

[Third Step] The post-record audio data input by the user in synchronization with the reproduction of the original data is encoded by the encoder 11 and the encoder buffer 12
To accumulate. The encoding process in the encoder 11 is continuously performed until the end of the after-recording operation regardless of the position of the optical pickup 2 and regardless of the read mode or the write mode.

[Fourth Step] Original data is extracted from the bypass buffer 8 and sent to the detector 9. When the detection result of the detector 9 indicates that the original data currently being taken out of the bypass buffer 8 is the video bit stream V or the main audio bit stream A1, the movable contact of the switch 10 is connected to the detector 9 side. By switching to the fixed contact, the original data is stored in the write channel buffer 13.

On the other hand, when the detection result of the detector 9 indicates that the original data currently being taken out of the bypass buffer 8 is the auxiliary audio bit stream A2, the movable contact of the switch 10 is set to the encoder buffer 12
After switching to the fixed contact on the side, the post-record audio data extracted from the encoder buffer 12 is stored in the write channel buffer 13. At the same time, by taking out the sub audio bit stream A2 from the bypass buffer 8 and continuing to flow it to the fixed contact of the detector 9, the write channel buffer 13 ignores the sub audio bit stream A2.

As a result, the original data and the post-record audio data are replaced by replacing the sub-audio bit stream A2 of the video bit stream V, the main audio bit stream A1, and the sub-audio bit stream A2 with the post-record audio data. The combined bit stream is accumulated in the write channel buffer 13.

The process of accumulating the data in the write channel buffer 13 is continuously performed until the end of the post-recording operation regardless of the position of the optical pickup 2 and the read mode or the write mode. This accumulation processing in the write channel buffer 13 corresponds to the stage after time T1 in FIG.

Subsequently, when a certain condition determined by one or a combination of two or more of the following factors (a) to (f) is satisfied, the reading of the original data is stopped. Switch 5 is switched to the write channel buffer 13 side. (A) Elapsed time from the start of reading (b) Data storage amount of read channel buffer 6 (c) Data storage amount of write channel buffer 13 (d) Media rate (read / write rate to optical disk 1) (e) ) Data rates of read channel and write channel (consumption rate of decoder 7, output rate of encoder 11) (f) Capacity of buffers 6 and 13

Finally, the address information of the original data sent to the read channel buffer 6 is stored. (When resuming the next reading, the original data following the data sent to the buffer 6 is read from the optical disk 1 based on the address information.) The switch 5 is switched at time T2 in FIG.
Stage.

Subsequently, based on the information stored in the system controller 14 in advance, the optical pickup 2 is caused to seek from the current position X2 to a write start position (here, the same position X0 as the read start position). X0
, The position of the optical pickup 2 is finely adjusted.

This seek operation corresponds to the stage from time T2 to time T3 in FIG. Taking FIG. 2 described above as an example, the position of the optical pickup 2 becomes R
From W to W.

Then, the optical pickup 2, RF and demodulation / modulation circuit 3, and ECC circuit 4 are switched to the write mode, and data is taken out from the write channel buffer 13. As a result, in the original data read from the optical disc 1, the data obtained by replacing the sub audio bit stream A2 with the post-record audio data is re-added with the error correction code, and then the area substantially equal to the original recording area on the optical disc 1 It is written to. In other words, in the area of the sub audio bit stream A2 corresponding to the reproduction time substantially equal to the recording area of the video bit stream V and the main audio bit stream A1 as the original data, the post-record audio data to be reproduced simultaneously with the original data. Are multiplexed and recorded.

This writing process corresponds to the stage from time T3 to time T4 in FIG. 3, and also shows that the amount of data stored in the write channel buffer 13 is reduced.

Subsequently, when a predetermined condition determined by the elapsed time from the start of writing and any one or a combination of two or more of the above factors (b) to (f) is satisfied, the optical disk 1 is stopped, and the switch 5 is again switched to the read channel buffer 6.
Switch to the side. Then, the address information of the last written data is stored. (When resuming the next write, based on this address information, data following the last written data is written to the write channel buffer 13.
Take it out from. The switching of the switch 5 corresponds to the stage at time T4 in FIG. With this fourth step, one cycle of the after-recording operation is completed.

Subsequently, based on the address information stored when the switch 5 was previously switched to the write channel buffer 13, the optical pickup 2 is sought from the current position X1 to the position X2 from which the previous reading was stopped. .

This seek operation corresponds to the stage from time T4 to time T5 in FIG. Taking FIG. 2 described above as an example, the position of the optical pickup 2 is changed to W by this seek operation.
From R to R. Thus, the position of the optical pickup 2 reciprocates between the reading position and the writing position.

Then, the optical pickup 2, the RF and demodulation / modulation circuit 3, and the ECC circuit 4 are set to the read mode again to finely adjust the position of the optical pickup 2, and then the reading by the optical pickup 2 is restarted. Hereinafter, until the writing of the post-record data corresponding to the original data to be post-recorded is completely completed (or until the user instructs the end of the post-recording by operating an operation panel (not shown)), as shown in the stage after time T5 in FIG. To
The above-described reading and writing are performed in a time-division manner.

In the example shown in FIG. 1, the detector 9 is provided at the subsequent stage of the bypass buffer 8. However, the detector 9 is provided at the previous stage of the bypass buffer 8, or the type of the packet media is detected by the decoder 7. Or you may. However, in this case, the system controller 14 needs to store the relationship between the detection result and the data stored in the bypass buffer 8.

Further, a detector for detecting not only the type of the medium but also the reproduction time of each packet based on the presentation time stamp in the packet may be provided. By doing so, the process of multiplexing and recording the after-recording audio data in the area corresponding to the reproduction time substantially equal to the recording area of the video bit stream V and the main audio bit stream A1 can be performed with higher accuracy.

In place of such a combination of the detector and the switch 10, a multiplexer for multiplexing the original data extracted from the bypass buffer 8 and the post-record audio data extracted from the encoder buffer 12 is provided. You may. By doing so, multiplexing can be performed more efficiently and with high accuracy, and multiplexing can be performed with a configuration different from the original original data.

FIG. 4 shows another example of the system configuration of an optical disc apparatus to which the after-recording method and apparatus of the present invention are applied when the above-mentioned (1) post-recording method is employed. Portions are given the same reference numerals, and redundant description is omitted.

In this optical disk device, two systems of work memories 16 and 17 are used as work memories for the ECC circuit 4.
Is provided, and data supplied to the ECC circuit 4 is temporarily stored in one of the work memories 16 and 17 via the switch 18 (in contrast to FIG. 1). In the optical disc device, the ECC circuit 4 is provided with only one work memory (not shown).

The processing executed by the system controller 14 at the time of post-recording in this optical disk apparatus has the following differences from the processing in the optical disk apparatus of FIG. 1, but the other points are the same as those of FIG. This matches the processing in the optical disk device.

[Difference in Read Mode] Original data read from the optical disk 1 and supplied to the ECC circuit 4 is temporarily stored in, for example, one work memory 16 via the switch 18.

When the switch 5 is switched to the write channel buffer 13 when a certain condition determined by one or a combination of two or more of the factors (a) to (f) is satisfied. Switch 18 is switched to the work memory 17 side.

When the reading of the original data is stopped and the address information is stored, the address information of the last sent original data is stored in the work memory 16 instead of the last sent original data in the read channel buffer 6. .

[Differences in Write Mode] When a certain condition determined by one or a combination of two or more of the factors (a) to (f) described above is satisfied, the switch 5 is set to the read channel. When switching to the work buffer 6 side, the switch 18 is again switched to the work memory 16 side.

The advantages of performing such processing are as follows. In the processing in the optical disk device shown in FIG. 1, since the ECC circuit 4 performs processing in units of data blocks of a fixed size, the data input to the ECC circuit 4 but not reaching the size of the data block Must be discarded in the ECC circuit 4 when the switch 5 is switched. Therefore, when the reading is restarted, the discarded data must be read out again from the optical disc 1, and when the writing is restarted, the discarded data must be taken out again from the write channel buffer 13, which is inefficient.

On the other hand, in the processing in the optical disk apparatus shown in FIG. 4, the data input to the ECC circuit 4 at the time of reading and writing but not reaching the size of the data block remains unchanged even after the switch 5 is switched. Since the data is held in the memories 16 and 17, the data following the data held in the work memory 16 only needs to be read from the optical disc 1 when reading is resumed, and the data following the data held in the work memory 17 is written to the writing channel even when writing is resumed. Since it suffices to take it out from the buffer 13, it is possible to perform the after-recording efficiently.

Next, the above-mentioned post-recording methods (1) to (3)
(3) is adopted (that is, after-recording audio data is recorded on a digital recording medium on which original data is recorded without being multiplexed with the original data, and read from the digital recording medium during reproduction. An example of the present invention in a case where original audio data and post-record audio data are mixed and output as a completed sound will be described.

FIG. 7 shows an example of the system configuration of an optical disc apparatus to which the after-recording method and apparatus of the present invention are applied when the after-recording method (3) is adopted. The same reference numerals are given and duplicate explanations are omitted. In this optical disk device, one system of optical pickup (optical head) 2 is provided for one rewritable optical disk 19, and this optical pickup 2 is shared for both reading and writing of data.
As shown in FIG. 8, a video bit stream V, a main audio bit stream A1, and a sub audio bit stream A2 are recorded on the optical disc 19. The video bit stream V and the main audio bit stream A1, which are original data, are recorded in a packet multiplexing system by the MPEG2 system (part R). The sub audio bit stream A2 is contained in packets by the packet multiplexing method of the MPEG2 system, but is recorded independently of the bit streams V and A1 (part W). In each bit stream V, A1 and A2,
There is a packet having a presentation timestamp at a rate of one for every several packets.

The bit stream read from the optical disk 19 by the optical pickup 2 is transmitted to the RF and demodulation / modulation circuit 3 (the modulation and RF
After demodulation and error correction are performed by the ECC circuit 4 (which has the functions of the ECC circuit 22 and the ECC circuit 28 in FIG. 6) respectively, It is sent to a read channel buffer 6 for absorbing the difference between the read rate and the decode processing rate.

The bit stream extracted from the read channel buffer 6 is decoded by a decoder (including a demultiplex unit, a video decoder, and an audio decoder) 7 and transmitted from a video output terminal P1 and an audio output terminal P2 to a display (not shown). , Sent to the speaker and reproduced.

On the other hand, the audio data input from the audio input terminal P 3 is encoded by the encoder 11 and then stored in the encoder buffer 12. The audio data extracted from the encoder buffer 12 is sent to the write channel buffer 13 via the multiplexer 20.

The data sent to the write channel buffer 13 (audio data taken out of the encoder buffer 12) is taken out of the write channel buffer 13 and passed through the switch 5 to the ECC circuit 4, RF and demodulation / modulation circuit. After the addition and modulation of the error correction code in step 3, the data is written on the optical disk 19 by the optical pickup 2.

In the case of this example, the reading rate and the writing rate are usually different from each other. In other words, since the read rate is the bit rate of a stream in which video and audio are multiplexed, and the write rate is the bit rate of a stream composed of one audio, the read rate is expected to be higher than the write rate. Is done.

Also in this optical disk device, after reading the bit stream from the optical disk 19 in this way, the audio data input in synchronization with the reproduction is read from the optical disk 19.
It takes several hundred milliseconds to several seconds for the reason described with reference to FIG.

Therefore, during the period from the reading to the writing, the position of the optical pickup 2 with respect to the optical disk 19 is advanced by this processing time.
However, in this example, the bit stream of the original data is the portion of R in FIG. 8, while the after-recording audio data is written in the portion of W in FIG. 8, as will be described later. Since it is a bit stream, no delay needs to be considered. That is, there is a time difference between the data being read and the data being written due to the signal processing delay, but this has no effect on the operation at the time of recording. However, as described later, the temporal correspondence between the bit stream of the original data and the bit stream of the after-recording audio data is recorded in the TOC area of the optical disc 19.

Returning to FIG. 7, the system controller 14
Is used to control the operation of each part of the optical disc device during post-recording as described later.
And R which stores a processing program to be executed by the CPU, etc.
It includes an OM and a RAM for temporarily storing data and the like generated during the processing. In this control, the fine adjustment of the position of the optical pickup 2 is performed by the detection of the address detection circuit 15 which takes in the bit stream demodulated by the RF and demodulation / modulation circuit 3 and detects the address information of the data currently being read. This is done based on the results.

Next, an example of the processing executed by the system controller 14 during post-recording will be described. [First Step] First, the user specifies the original data to be post-recorded by operating an operation panel (not shown) or reads out the specification information of the original data to be post-recorded previously written on the optical disc 19. Then, of the original data recorded on the optical disc 19, the range of the original data to be dubbed is determined.

Subsequently, the optical pickup 2 is sought to the read start position X0 based on the address information of the original data to be post-recorded. Then, the optical pickup 2, the RF and demodulation / modulation circuit 3, and the ECC circuit 4 are set to the read mode, and the switch 5 is switched to the read channel buffer 6 to finely adjust the position of the optical pickup 2. Starts reading. As a result, the original data to be post-recorded is accumulated in the read channel buffer 6.

FIG. 9 shows the relationship between the position of the optical pickup 2 and the read / write status at each time during the after-recording operation (FIG. 9A), and the read channel buffer 6 and the write channel buffer 13 at these times. Are shown in FIG. FIG. 9A
In the figure, a thick solid line indicates that reading is being performed, a broken line indicates that writing is being performed, and a thin solid line indicates that seeking is being performed.

In FIG. 9, the accumulation process in the read channel buffer 6 corresponds to the stage from time T0 to T2, and FIG. 9 also shows that the data accumulation amount of the read channel buffer 6 increases. Is appearing.

[Second Step] Original data is extracted from the read channel buffer 6, decoded by the decoder 7, and reproduced.

The decoding process in the decoder 7 is continued until the end of post-recording regardless of the position of the optical pickup 2 and regardless of the read mode or the write mode. This decoding process is started between time T0 and time T1 in relation to FIG.

[Third Step] The post-record audio data input by the user in synchronization with the reproduction of the original data is encoded by the encoder 11 and the encoder buffer 12
To accumulate. The encoding process in the encoder 11 is continuously performed until the end of the after-recording operation regardless of the position of the optical pickup 2 and regardless of the read mode or the write mode.

[Fourth Step] Encoder Buffer 12
The dubbed audio data taken out of the above is stored in a packet conforming to the MPEG2 system standard by the multiplexer 20 and stored in the write channel buffer 13.

As a result, a bit stream temporally corresponding to the original data is created and stored in the write channel buffer 13.

The accumulation process in the write channel buffer 13 is continuously performed until the end of post-recording regardless of the position of the optical pickup 2 and regardless of the read mode or the write mode. This accumulation process in the write channel buffer 13 corresponds to the stage after time T1 in FIG.

Subsequently, when a certain condition determined by one or a combination of two or more of the following factors (a) to (f) is satisfied, the reading of the original data is stopped. Then, the switch 5 is again switched to the write channel buffer 13 side. (A) Elapsed time from the start of reading (b) Data storage amount of read channel buffer 6 (c) Data storage amount of write channel buffer 13 (d) Media rate (read / write rate for optical disk 19) (e) ) Data rates of read channel and write channel (consumption rate of decoder 7, output rate of encoder 11) (f) Capacity of buffers 6 and 13

Then, the address information of the original data sent to the read channel buffer 6 last is stored. (When resuming the next reading, the original data following the data last sent to the buffer 6 is read from the optical disk 19 based on this address information.) The switch 5 is switched at time T2 in FIG. Stage.

Subsequently, based on the information stored in the system controller 14 in advance, the optical pickup 2 is moved from the current position X2 to the writing start position (here, the position of the original data recording position R in FIG. 8). 8 is a recording position of the sub audio bit stream A2 which does not overlap.
To the position Y0) in the W portion of
When the distance approaches 0, the position of the optical pickup 2 is finely adjusted.

This seek operation corresponds to the stage from time T2 to T3 in FIG. Taking the example of FIG. 8 described above as an example, the position of the optical pickup 2 becomes R by this seek operation.
From W to W.

Then, the optical pickup 2, RF and demodulation / modulation circuit 3, and ECC circuit 4 are switched to the write mode, and data is taken out from the write channel buffer 13. Thus, the post-record audio data is written on the optical disc 19 after the error correction code is added.

This write processing corresponds to the stage from time T3 to time T4 in FIG. 9, and FIG. 9 also shows that the amount of data stored in the write channel buffer 13 decreases.

Subsequently, when a certain condition determined by the elapsed time from the start of writing and any one or a combination of two or more of the above factors (b) to (f) is satisfied, The writing of data to 19 is stopped, and the switch 5 is switched again to the read channel buffer 6 side. Then, the address information of the last written data is stored. (When resuming the next writing, the data following the last written data is written to the write channel buffer 1 based on the address information.
Take it out of 3. The switching of the switch 5 corresponds to the stage at time T4 in FIG. With this fourth step, one cycle of the after-recording operation is completed.

Subsequently, based on the address information stored when the switch 5 was previously switched to the write channel buffer 13, the optical pickup 2 is sought from the current position Y1 to the position X2 where the previous reading was stopped. .

This seek operation corresponds to the stage from time T4 to T5 in FIG. Taking the example of FIG. 8 described above as an example, the position of the optical pickup 2 becomes W by this seek operation.
From R to R. Thus, the position of the optical pickup 2 reciprocates between the reading position and the writing position.

Then, the optical pickup 2, the RF and demodulation / modulation circuit 3, and the ECC circuit 4 are switched to the reading mode again, and after the position of the optical pickup 2 is finely adjusted, the reading by the optical pickup 2 is restarted. Hereinafter, until all the writing of the post-record data corresponding to the original data to be post-recorded is completed (or until the user instructs the end of the post-recording by operating an operation panel (not shown)), as shown in a stage after time T5 in FIG. To
The above-described reading and writing are performed in a time-division manner.

[Fifth Step] As a final stage of post-recording, information indicating a temporal correspondence between original data and post-recording audio data is recorded on the optical disc 19. Here, as an example, a presentation time stamp (PTS) is used. That is, as described above, in the MPEG2 system, since the packets of the bit stream of each media have a presentation time stamp, as shown in FIG. Presentation time of a portion of the main audio bit stream A1 that starts to correspond to the audio bit stream A2, which is post-record audio data (ie, the beginning of the original data to be post-recorded specified by the user or the specification information written on the optical disc 19). The stamp uniquely identifies the temporal correspondence between the original data and the after-recording audio data.

Therefore, when all of the post-recording audio data corresponding to the original data to be post-recorded are completed or when the user instructs the end of post-recording, the system controller 14 starts to correspond to the post-recording audio data in the original data. Information indicating the presentation time stamp of the portion is recorded in a TOC (Table Of Contents) area of the optical disc 19. Further, address information of a portion (X0 in FIG. 9) of the original data which starts to correspond to the after-recording audio data,
Address information of the start position (Y0 in FIG. 9) and the end position of the post-record audio data is also recorded in the TOC area.

As described above, as the information indicating the temporal correspondence between the original data and the post-recording audio data, the information indicating the presentation time stamp of the portion of the original data which starts to correspond to the post-recording audio data is the TOC of the optical disc 19. Since the original data and the post-record audio data are recorded without being multiplexed because they are recorded in the area, the post-record audio data exactly matches the original data in time based on this information in the TOC. It can be played back.

FIG. 11 shows an example of the system configuration of an optical disk apparatus to which the reproducing method and apparatus of the present invention are applied when the above-mentioned after-recording method (3) is employed. This optical disk device is provided with one system of an optical pickup (optical head) 31 for reading data. A bit stream read by the optical pickup 31 from an optical disk mounted on the optical disk device is subjected to an RF and demodulation circuit. 32 (having the function of the RF and demodulation circuit 21 in FIG. 6) and the ECC circuit 33 (the ECC circuit 22 in FIG. 6).
After performing demodulation and error correction with the buffer 35a, the buffer 35 (the buffer 35a of the channel (Ch) 1 and the channel 35a) absorbs the difference between the read rate and the decode processing rate via the switch 34. (C
h) any one of the two buffers 35b).

The bit stream extracted from the Ch1 buffer 35a is supplied to a decoder (including a demultiplex unit, a video decoder and an audio decoder) 36
Decoded by a. The video signal output from the decoder 36a is sent from a video output terminal P1 to a display (not shown), and the audio signal output from the decoder 36a is sent to a mixing circuit 37.

On the other hand, the bit stream extracted from the buffer 35b of Ch2 is decoded by a decoder (including an audio decoder) 36b, and the audio signal output from the decoder 36b is sent to a mixing circuit 37.
The audio signal output from the mixing circuit 37 is sent from an audio output terminal P2 to a speaker (not shown) and reproduced.

Although not shown, the TOC information read from the optical disk by the optical pickup 31 is sent to the system controller 38 after being subjected to demodulation and error correction by the RF and demodulation circuit 32 and the ECC circuit 33, respectively. . The system controller 38 controls the operation of each unit of the optical disk device during reproduction as described later. Although not shown, the system controller 38 includes a CPU, a ROM storing processing programs to be executed by the CPU, and the like. And a RAM for temporarily storing generated data and the like. still,
In this control, the fine adjustment of the position of the optical pickup 31 is performed based on the detection result of the address detection circuit 39 which receives the bit stream demodulated by the RF and demodulation / modulation circuit 32 and detects the address information of the data currently being read. It is done based on.

Next, an example of a process executed by the system controller 38 during reproduction of the optical disk 19 (recorded by the optical disk device of FIG. 7) will be described. [First Step] The optical disc 19 is set on the optical pickup 31.
When the TOC information is read out, information indicating the presentation time stamp of a portion of the original data which starts to correspond to the after-recording audio data, which is the information recorded by the optical disk device of FIG. The address information of the part (X0 in FIG. 9) which starts to correspond to the post-record audio data, and the address information of the start position (Y0 in FIG. 9) and the end position of the post-record audio data are obtained.

[Second Step] When the user designates the reproduction start position of the original data (the video bit stream V and the main audio bit stream A1 in FIG. 8) by operating the operation panel (not shown), the address information of the reproduction start position is set. Then, the optical pickup 31 is sought to the reproduction start position. Then, the switch 34 is switched to the buffer 35a side of Ch1, and after the position of the optical pickup 31 is finely adjusted, reading by the optical pickup 31 is started. Then, the original data stored in the buffer 35a is taken out from the buffer 35a and
6a, and starts the decoding process in the decoder 36a.

As a result, the original video is reproduced and the original audio is reproduced as it is via the mixing circuit 37. Since the consumption rate of the decoder 36a is lower than the reading rate from the optical disk 19, when the original data is accumulated in the buffer 35a to the full capacity, the reading of the original data from the optical disk 19 is interrupted, and then the buffer 35a When there is enough free space in the buffer 35a by taking out the data, reading from the optical disk 19 is restarted.

The original data is read out in this manner, and a portion having the same presentation time stamp as the presentation time stamp indicated by the information obtained in the first step (X0 in FIG. 9, P0 in FIG. 10).
When the data reaches the TS portion, the data storage amount of the buffer 35a becomes the minimum necessary amount (for example, the full capacity) determined from the following factors (g) to (j). At this point, the reading of the original data is stopped and the extraction of the original data from the buffer 35a is stopped, and the switch 34 is switched to the buffer 35b of Ch2. (G) Elapsed time from when a portion having the same presentation time stamp as the presentation time stamp indicated by the information obtained in the first step is reached. (H) Media rate (rate of reading / writing to / from optical disc 19) (i) Ch1, Ch2 data rate (decoder 36
(j) The capacity of the buffers 35a and 35b

Then, the address information of the original data finally sent to the buffer 35a is stored. (When the reading of the original data is restarted next time, the original data following the data sent to the buffer 35a is read from the optical disk 19 based on the address information.)

Subsequently, based on the address information obtained in the first step, the optical pickup 31 seeks from the current position to the start position of the post-record audio data (Y0 in FIG. 9), and the position of the optical pickup 31 is changed. After the fine adjustment, reading by the optical pickup 31 is started. Thereby, the post-record audio data (the sub-audio bit stream A2 in FIG. 8) is accumulated in the buffer 35b.

[Third Step] Subsequently, the buffer 35b
Has become the minimum necessary amount (for example, the full capacity) determined from the factors (h) to (j) and the following factors (k) and (l). At that point,
Original data and post-record audio data are respectively extracted from the buffer 35a of Ch1 and the buffer 35b of Ch2, and sent to the decoders 36a and 36b.
Also starts the decoding process. (K) Elapsed time from the start of reading of post-record audio data (l) Data storage amount of buffer 35a of Ch1 The minimum required data storage amount of buffer 35b is the minimum required amount of buffer 35a. It may be smaller than the required data storage amount. This is because the readout of the post-record audio data is continued even after the start of the decoding process in the decoder 36b, so that the risk of underflow occurring in the buffer 35b is reduced.

In this example, in the second step, when a part having the same presentation time stamp as the presentation time stamp indicated by the information obtained in the first step is reached, the extraction of the original data from the buffer 35a of Ch1 is stopped. (Accordingly, the decoding process of the original data in the decoder 36a is stopped), and in the subsequent third step, the extraction of the post-recording audio data from the buffer 35b of Ch2 is started, and the decoding process of the post-recording audio data in the decoder 36b is started. Simultaneously with the start, the retrieval of the original data from the buffer 35a is restarted (the decoding process of the original data in the decoder 36a is restarted). However, as another example, in the second step, even when a part having the same presentation time stamp as that indicated by the information obtained in the first step is reached, the retrieval of the original data from the buffer 35a is continued (therefore, the decoder is executed). The decoding process of the original data in the decoder 36a is continued). With the decoding process continued in the decoder 36a in this manner, in the third step, the extraction of the post-record audio data from the buffer 35b is started, and the decoding in the decoder 36b is started. The decoding process of the post-record audio data may be started.

[Fourth Step] Thus, the original video is reproduced, and the original audio and the after-recording audio are mixed by the mixing circuit 37 and started to be reproduced.

Subsequently, for example, the above (h) to (j),
When a certain condition determined from each factor such as (k), (l) and the following (m) is satisfied, the reading of the post-record audio data is stopped, and the switch 34 is again moved to the Ch1 buffer 35a side. Switch. (M) Data accumulation amount in the buffer 35b of Ch2 Then, the address information of the post-record audio data sent to the buffer 35b last is stored. (When resuming the next reading of the post-recording audio data, the post-recording audio data subsequent to the data sent to the buffer 35b is read from the optical disc 19 based on the address information.)

Subsequently, based on the address information stored when the switch 34 was previously switched to the buffer 35b of Ch2, the optical pickup 31 is caused to seek from the current position to the position of the original data from which reading was previously stopped. After the position of the optical pickup 31 is finely adjusted, reading by the optical pickup 31 is started. Hereinafter, the reading of the original data and the recording of the post-recording audio data as described above until the reading of the post-recording audio data to the end position is all completed (or until the user instructs the end of the reproduction by operating an operation panel (not shown)). Reading is performed in a time sharing manner.

FIG. 12 shows the reading state of the optical pickup 31 in the steady state during reproduction (A in FIG. 12),
An example is shown of the data accumulation amounts (B and C in the same figure) of the buffer 35a of Ch1 and the buffer 35b of Ch2. In FIG. 12A, Ch1 is a period during which original data is being read, Ch2 is a period during which post-record audio data is being read, Tp is a period during seek, Tc is a repetition period of time-division reading, and Rm Is the optical disk 19
Read rate from the

In FIG. 12, at time T0, buffer 3
The reading of the original data is restarted before the data storage amount of 5a becomes zero, and the reading of the original data is stopped at a time T1 thereafter, and the optical pickup 31 moves the recording position of the post-recording audio data between the times T1 and T2. After that, at time T2, the reading of the post-record audio data is restarted before the data storage amount of the buffer 35b becomes zero, and at the subsequent time T3, the reading of the post-record audio data is stopped. In the meantime, the optical pickup 31 seeks to the recording position of the original data, and the same process is repeated thereafter.

In FIG. 12, the relationship between the length of the period during which the original data is being read and the period during which the post-record audio data is being read, and the relationship between the amount of data stored in the buffer 35a and the amount of data stored in the buffer 35b, The relationship is neglected and drawn. However, the original data consists of the video bit stream V and the main audio bit stream A1, whereas the post-record audio data consists only of the sub-audio bit stream A2. It is needless to say that the period is longer than the period and the data storage amount of the buffer 35a may be larger than the data storage amount of the buffer 35b.

As described above, the information indicating the presentation time stamp of the portion of the original data which starts to correspond to the after-recording audio data is read out from the TOC area of the optical disc 19, and based on this information, the original data and the after-recording audio data are read. Is read out and decoded in synchronization with the original data and the post-recording audio data are recorded without multiplexing at the time of post-recording. It is played back with matching.

In each of the above examples, reading and writing (or reading of data of two channels) are performed in a time-division manner by seeking one system of optical pickup, but reading and writing are performed by providing two systems of optical pickup. (Or reading of data of two channels) may be performed independently.

In the above example, the present invention is applied to an optical disk device equipped with a rewritable optical disk. However, for example, an appropriate rewritable disk-shaped recording medium such as a magnetic disk (or other than a disk-shaped recording medium). The present invention may be applied to a recording / reproducing apparatus equipped with a random access type digital recording medium). When two heads are provided, the present invention may be applied to a recording / reproducing apparatus equipped with a digital recording medium of a sequential access system such as a magnetic tape.

Further, in the above example, the present invention is applied to a recording medium on which original data is recorded by the packet multiplexing method, but the present invention may be applied to a digital recording medium on which original data is recorded by an appropriate method. .

In the above example, the audio data is dubbed on the original data composed of the video bit stream V and the main audio bit stream A1, but the original data composed of the bit stream of the appropriate media type is used. The present invention may be applied to a case where appropriate data of a new type is dubbed. That is, for example, after-recording of at least one of audio data and graphic data is performed on original data consisting of only a video bit stream (or consisting of a video bit stream and an audio bit stream), or The present invention may be applied to a case where after-recording of at least one of video data and graphic data is performed on the original data.

[0138] Mixing at the time of reproduction when the above-mentioned (3) post-recording method is employed is also different from that of the main audio bit stream A as in the optical disk apparatus of FIG.
1 and the sub audio bit stream A2, but may be performed on a video bit stream of the original data and a video bit stream or graphic bit stream of the post-record data.

Further, the present invention is not limited to the above embodiments,
It goes without saying that various other configurations can be adopted without departing from the gist of the present invention.

[0140]

As described above, according to the post-recording method and apparatus according to the present invention, the temporal relationship between the recording area of the original data and the recording area of the post-recording data becomes clear, so that the video and audio as a completed work can be obtained. Is reproduced, it is possible to easily reproduce the after-recording data with the original data accurately in time.

In particular, according to the after-recording method and apparatus of the eighth and fourteenth aspects, information indicating the temporal correspondence between the original data and the after-recording data is recorded in the recording area of the additional information of the digital recording medium. Therefore, although the original data and the post-record data are recorded without being multiplexed, based on this information, the post-record data can be reproduced exactly in time with the original data. can get.

According to the reproducing method and apparatus according to the fifteenth and eighteenth aspects of the present invention, the temporal correspondence between the original data and the post-recording data is shown from the recording area of the additional information on the digital recording medium. Information is read,
Based on this information, the original data and the post-record data are read out and decoded in synchronization, so that even if the original data and the post-record data are recorded without being multiplexed at the time of post-recording, the post-record data is recorded as the original data. The effect is obtained that the reproduction can be performed with the time being exactly matched.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an example of a system configuration of an optical disc device to which the present invention has been applied.

FIG. 2 is a diagram illustrating an example of a relationship between a read position and a write position of the optical pickup.

FIG. 3 is a diagram illustrating an example of a relationship between a position of an optical pickup and a read / write state, and an amount of data stored in a buffer.

FIG. 4 is a block diagram showing another example of the system configuration of the optical disc device to which the present invention is applied.

FIG. 5 is a diagram illustrating an example of recording data on a digital recording medium.

FIG. 6 is a diagram illustrating an example of a conventional post-recording process.

FIG. 7 is a block diagram illustrating an example of a system configuration of an optical disc device to which the present invention has been applied.

FIG. 8 is a diagram illustrating an example of a relationship between a read position and a write position of the optical pickup.

FIG. 9 is a diagram illustrating an example of a relationship between a position of an optical pickup and a reading / writing state, and an amount of data stored in a buffer.

FIG. 10 is a diagram showing a presentation time stamp of a portion of the original data that starts to correspond to the post-record audio data.

FIG. 11 is a block diagram showing another example of the system configuration of the optical disk device to which the present invention has been applied.

FIG. 12 is a diagram illustrating an example of a reading state of an optical pickup and a data accumulation amount in a buffer during time-division reproduction.

[Explanation of symbols]

1,19 ‥‥ optical disk, 2,31 ‥‥ optical pickup, 3 ‥‥ RF and demodulation / modulation circuit, 4,33 ‥‥ EC
C circuit, 5, 10, 18, 34 switch, 6 read channel buffer, 7, 36a, 36b decoder, 8 bypass buffer, 9 detector, 11
{Encoder, 12} Encoder buffer, 13}
{Write channel buffer, 14, 38} System controller, 15, 39} Address detection circuit, 1
6, 17 work memory, 20 multiplexer, 32 work
‥ RF and demodulation circuit, 35a ‥‥ Ch1 buffer, 3
5b ‥‥ Ch2 buffer, 37 ‥‥ mixing circuit

Claims (20)

[Claims] 1. a first step of reading a bit stream from a digital recording medium; a second step of decoding the bit stream; and synchronizing with the decoding of the bit stream, encoding new data to perform after-recording. An after-recording method for a digital recording medium, comprising: a third step of forming a bit stream; and a fourth step of writing the after-recording bit stream to a predetermined area of the digital recording medium. 2. In the first step, a bit stream including at least one of a video bit stream and an audio bit stream is read, and in the third step, at least one of audio data, video data, and graphic data is read. 2. The after-recording method for a digital recording medium according to claim 1, wherein one of the two is encoded to form a bit stream for after-recording. 3. In the first step, a bit stream including a video bit stream and at least one audio bit stream is read, and in the third step,
3. The after-recording method for a digital recording medium according to claim 2, wherein the audio data is encoded into a bit stream for after-recording. 4. The digital recording medium has a recording area for a video bit stream, a main audio bit stream, and a sub audio bit stream. In the fourth step, the after-recording bit stream is converted to the sub audio data. 4. The after-recording method for a digital recording medium according to claim 3, wherein writing is performed in a recording area of a bit stream. 5. The digital recording medium is a rewritable disk-shaped recording medium, wherein the first step and the fourth step are performed using a common read / write head in a time-division manner. The after-recording method for a digital recording medium according to claim 1. 6. In the second step, the bit stream is stored in a buffer while being sent to a decoder, and in the fourth step, the bit stream extracted from the buffer and the bit stream for after-recording are combined. The after-recording method for a digital recording medium according to any one of claims 1 to 5, wherein the after recording is performed on the digital recording medium. 7. The method according to claim 1, wherein in the fourth step, the after-recording bit stream is multiplexed with the bit stream read in the first step and written. Recording method for digital recording media. 8. In the fourth step, the after-recording bit stream is written without being multiplexed with the bit stream read in the first step, and the after-recording bit stream and the bit stream are written. 7. The after-recording in a digital recording medium according to claim 1, further comprising a fifth step of writing information indicating a temporal correspondence relationship into a recording area of the additional information of the digital recording medium. Method. 9. A reading means for reading a bit stream from a digital recording medium, a decoder for decoding the bit stream read from the digital recording medium by the reading means, and a bit stream for after-recording by encoding new data. An encoder for writing the bit stream for after-recording to the digital recording medium; and a bit for the after-recording encoded by the encoder in synchronization with the decoding of the bit stream by the decoder. Control means for controlling the writing means to write the stream to a predetermined area of the digital recording medium, the after-recording apparatus for the digital recording medium comprising: . 10. The digital recording medium has a recording area for a video bit stream, a main audio bit stream, and a sub audio bit stream, and the reading means outputs at least one video bit stream from the recording area. Reading a bit stream including an audio bit stream, the encoder encodes audio data into a bit stream for after-recording, and the control unit records the bit stream for after-recording, recording the sub-audio bit stream. The after-recording apparatus for a digital recording medium according to claim 9, wherein the after-recording is performed in an area. 11. The digital recording medium is a rewritable disk-shaped recording medium, wherein the read means and the write means are a common read / write head, and wherein the control means is the read / write head. The after-recording apparatus according to claim 9 or 10, wherein the after-recording bit stream is written by using time division. 12. A buffer for storing the bit stream read by the reading unit, wherein the control unit writes the bit stream extracted from the buffer in combination with the bit stream for after-recording. The after-recording apparatus for a digital recording medium according to claim 9, wherein the after-recording is performed. 13. The method according to claim 9, wherein the control unit multiplexes the bit stream for after-recording with the bit stream read by the reading unit and writes the multiplexed bit stream. An after-recording device for digital recording media. 14. The control means writes the after-recording bit stream without multiplexing with the bit stream read by the reading means, and writes the after-recording bit stream and the bit stream. The after-recording apparatus for a digital recording medium according to any one of claims 9 to 11, wherein information indicating a temporal correspondence with the information is written in a recording area of the additional information of the digital recording medium. 15. A bit stream of original data subjected to after-recording from a recording area of additional information on a digital recording medium and data for after-recording written without being multiplexed with the bit stream of the original data. A second step of reading out information indicating a temporal correspondence relationship with the bit stream of the first data, and a second step of reading out the bit stream of the after-recording data in synchronization with the bit stream of the original data based on the information. Decoding the bit stream of the original data and the bit stream of the after-recording data, and reproducing the after-recorded digital recording medium. 16. The method according to claim 1, further comprising a fourth step of mixing the bit stream of the original data decoded in the third step and the bit stream of the after-recording data.
6. The method for reproducing the after-recorded digital recording medium according to 5. 17. The method according to claim 15, wherein the digital recording medium is a disk-shaped recording medium, and the second step is performed using one read head in a time-division manner.
19. The method for reproducing an after-recorded digital recording medium according to item 16. 18. A reading means for reading a bit stream from a digital recording medium, the reading means comprising: a bit stream of original data subjected to after-recording from a recording area of additional information of the digital recording medium; The bit stream of the original data and the information indicating the temporal correspondence with the bit stream of the after-recording data written without being multiplexed are read, and the reading unit is controlled based on the information. Control means for synchronously reading the bit stream of the original data and the bit stream of the after-recording data, and a decoder for decoding the bit stream read from the digital recording medium by the reading means. Features Reproducing apparatus after recording digital recording medium that. 19. The after-recording apparatus according to claim 18, further comprising mixing means for mixing the bit stream of the original data decoded by the decoder and the bit stream of the after-recording data. Digital recording media playback device. 20. The digital recording medium is a disk-shaped recording medium, the reading means is one reading head, and the control means uses the one reading head in a time-division manner to read bits of the original data. 20. A stream and a bit stream of the after-recording data are read.
3. A playback device for an after-recorded digital recording medium according to claim 1.