JPH0877708A - Recording device and reproducing device - Google Patents

Abstract

PURPOSE: To enable a decoder to accurately restore data by causing a data packet string obtained from a signal source in a recording device equal to the output timing of a data packet string obtained from a reproducing block in a reproducing device. CONSTITUTION: Variety data 123 representing the frequency of a carrier clock 121 output from a tuner 101, information 126 on the number of carrier clocks within the one cycle period of a reference signal 122 and time information 128 obtained by the carrier clock in a position between the packets are recorded in a recording block 102. Data from the tuner 101 is recorded in this block 102 at the same time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording device and a reproducing device for recording and reproducing compressed video and audio data.

[0002]

2. Description of the Related Art Currently, a digital VTR for recording video and audio as digital signals on a magnetic tape is under development. Since the video signal has a very large amount of information, if it is recorded on the tape as it is, the amount of the tape used becomes very large, which is not suitable for consumer use. Therefore, data compression is performed to reduce the tape consumption to the extent that it can be used for consumer use. In the currently developed digital VTR, the data compression circuit is completed within one frame so as to reduce the circuit scale. When data compression is performed by this method, the amount of data in one frame of the video signal becomes constant. Further, also in the audio signal, the data amount in one frame is made constant by adding dummy data. That is, in the digital VTR currently under development, the amount of data recorded on the tape within one frame period of the video signal input to the digital VTR is always constant. In other words, the digital VTR records the audiovisual data on the tape at a constant recording rate in synchronization with the frame signal of the input video signal.

At the time of reproduction, a frame reference signal corresponding to the frame signal of the video signal is generated inside the digital VTR to synchronize the rotary head of the VTR and the tape feed speed with the reference signal. The data recorded on the tape is reproduced from the tape in synchronization with this reference signal. At this time, the amount of data reproduced within one frame period divided by the reference signal is constant. The reproduced audio data is subjected to a predetermined process such as removal of added dummy data, etc., and then converted into an analog audio signal, and then a digital VTR.
It is output to the outside. Further, since the video data is subjected to data compression which is completed within one frame, the data is decompressed, converted into an analog video signal and output to the outside.

However, in order to further reduce the amount of data after compression of video and audio, development of a data compression system of an international standard called MPEG2 is in progress. In this method, in particular, the video signal is compressed using video data of a plurality of frames, and the data amount of the input video signal is different for each frame. In this system, each frame of the compressed video signal is a frame that is compressed to complete within one frame called an I frame, a B frame and a P frame.
Each frame is composed of a frame that is composed of only difference data between frames. Since the I frame is compressed so that it is completed within one frame, the compression rate cannot be increased, and the amount of data after compression is very large as compared with other B frames and P frames. Further, since the B frame and the P frame are composed only of the difference values from the adjacent frame and the I frame, the data amount of these frames after compression is very small. MP like this
The video data compressed by the method of EG2 has a different data amount for each frame.

In the MPEG2 system, a packet called a transport stream packet (hereinafter referred to as TS packet) is defined so that compressed data can be transmitted to another device or recorded on a recording medium. The compressed video data and audio data are divided into a plurality of TS packets, packetized and transmitted or recorded. Also, different TS packets are used for audio data and video data.

[0006] Furthermore, MPEG2 is specified so that not only one program can be transmitted and recorded but also a plurality of programs and character information can be transmitted or recorded. The video data and audio data of each program are packetized into TS packets, and similarly, the character information is also packetized.
Each TS packet of these plural programs and character information is multiplexed and transmitted and recorded.

At present, in the United States, a "broadcast system which uses terrestrial waves to transmit video and audio as digital signals with the same bandwidth as the current broadcast system" has been developed. In this system, TS packets are packetized according to the MPEG2 system, and each TS packet of video data and audio data of one program or a plurality of programs is multiplexed. The data rate of TS packets after multiplexing is a predetermined data rate (for example, about 19.3 Mbps).
In the ATV, a predetermined error correction parity is added to this TS packet, and the TS packet is modulated by a predetermined method and broadcast using terrestrial waves. This system is currently being implemented using terrestrial waves, but it can also be applied to satellite broadcasting, cable television, and the like. Further, the current data rate of TS packets is about 19.3 Mbps, but a higher transmission rate (for example, about 38 times as high as about 38 times) is used in order to broadcast a program with higher image quality or to broadcast more programs at the same time. ．
It is also considered to be broadcast at 6 Mbps).

In Europe, digital broadcasting called DVB is also under development. DVB also adopts the MPEG2 system like ATV, but DVB is designed to multiplex and broadcast a plurality of programs. Since the number of programs to be multiplexed is variable, there are multiple data rates.

The digital VTR currently being developed is
As described above, it is recorded in synchronization with the frame of the video signal. The recording rate of this VTR is the VTR for the current broadcasting system.
Is about 25 Mbps, and the VTR for high-definition broadcasting is about 50 Mbps. Therefore, if the data rate of ATV (about 19.3 Mbps), it is possible to record with the VTR for the current broadcasting system.

A possible method for recording a bit string of an MPEG2 TS packet in the above digital VTR will be described. In this explanation, the recording rate of VTR is about 25.
An example is a VTR for current broadcasting, which is Mbps.
During recording, the VTR independently generates a frame reference signal inside the VTR. This frame reference signal is the input MPE
This signal is independent of the data rate of the G2 TS packet. Therefore, the MPEG2 TS recorded on the tape within each frame period determined by the frame reference signal described above.
The data amount of the packet differs for each frame.
When recording the data rate of a TS packet of MPEG2 of 19.3 Mbps in a VTR having a recording rate of 25 Mbps, dummy data is recorded to complement the data rate corresponding to the difference. Since the amount of data recorded by the VTR for each frame is constant, the VTR is set to 1
The data amount of the TS packet sequence of MPEG2 recorded within the frame period differs for each frame.

Next, a method of reproducing a tape recorded by such a method will be described. The VTR reproduces in synchronization with the internal frame reference signal. The data reproduced from the tape is reproduced at a reproduction rate of about 25 Mbps. When outputting data from the VTR playback device, the dummy data added during recording is removed, and only the MPEG2 TS packet data is output.

FIG. 7A shows a packet sequence of MPEG2 TS packets input to the recording device of the VTR during recording. The TS packet 701 is input at a data rate of 19.3 Mbps. As shown in FIG. 7B, the dummy data 702 is added and recorded so that the recording rate becomes about 25 Mbps. Figure 7 from the top of the tape during playback
As shown in (B), it is reproduced at a reproduction rate of about 25 Mbps. When extracting data from the VTR playback device,
As shown in FIG. 7C, the dummy data 702 is taken out in the removed state. The data string in FIG. 7C is synchronized with the frame reference signal inside the VTR.

When the data rate input to the VTR recording device is higher than the VTR recording rate, for example, MPE
The data rate of the G2 TS packet sequence is 38.6 Mbp
If the recording rate of the VTR is 25 Mbps in s, it is not possible to record all the input data. In order to record such high data rate data, a VTR having a higher recording rate is required. In the case of this conventional example, the recording rate corresponding to high-definition broadcasting is about 50 Mbps.
VTR will be used.

[0014]

The problems to be solved by the present invention will be described. When an MPEG2 TS packet in which a plurality of programs are multiplexed like DVB is input and recorded, if the data rate of the MPEG2 TS packet sequence is less than the recording data rate of the VTR, all the programs can be recorded as they are. It is possible. However,
When the recording data rate of the VTR is exceeded, a program is selected from the multiplexed programs so as to be within the recording data rate of the VTR, and MPE having an identifier indicating the program is selected.
The G2 TS packet is extracted and recorded. During playback,
Dummy data is added in order to output the MPEG2 TS packet sequence to the decoder at the same data rate as when it was input. The MPEG2 TS packet recorded at this time is
When it is output to the decoder, it is discretely transmitted by the dummy data. This MPEG2 TS packet sequence must have the same timing as much as possible, but an error occurs in realizing these with the conventional technology, which exceeds the allowable error of the decoder, and the video data and audio data are reproduced accurately. It is not possible.

[0015]

Claim 1 according to the present invention
The recording device described above includes a carrier clock detecting means for detecting a frequency type of a carrier clock carrying packetized data, a first carrier clock counting means for counting the number of carrier clocks within a predetermined period, and Second carrier clock counting means for counting time information obtained by a carrier clock at a packet delimiter position, the packetized data, information indicating the type of frequency, the number of carrier clocks, and the time information. Is provided on the recording medium.

According to another aspect of the present invention, there is provided a reproducing apparatus, wherein data recorded on a recording medium, information indicating a frequency type of a carrier clock, the number of carrier clocks within a predetermined period, and time information. And a carrier clock generating means for generating a carrier clock according to the frequency type of the carrier clock,
It is characterized by further comprising a reference signal generating means for generating a reference signal equal to the predetermined period according to the number of carrier clocks, and an output control means for controlling output of the data according to the time information.

A recording apparatus according to a third aspect of the present invention counts a carrier clock detecting means for detecting a frequency type of a carrier clock carrying packetized data, and the number of carrier clocks within a predetermined period. First carrier clock counting means, and second carrier clock counting means for counting time information obtained by the carrier clock at the packet delimiter position,
Recording start position detecting means for detecting a recording start position of the packetized data; and the packetized data,
Recording means for recording the information indicating the frequency type, the carrier clock number, the time information, and a flag indicating the recording start position on a recording medium is provided.

According to a fourth aspect of the present invention, there is provided a reproducing apparatus in which data recorded on a recording medium, information indicating a carrier clock frequency type, the number of carrier clocks within a predetermined period, and time information. Reproducing means for reproducing a recording start position flag, carrier clock generating means for generating a carrier clock according to the type of frequency of the carrier clock, and a reference signal equal to the predetermined cycle according to the number of carrier clocks. A reference signal generating means, an output control means for controlling the output of the data according to the time information, and an output time correcting means for correcting the output time of the data at the recording start position by the flag. Playback device.

[0019]

According to another aspect of the present invention, there is provided a recording device for detecting a carrier clock frequency type of video data and audio data transmitted in packet units, and for generating a carrier within an internal reference signal period generated every predetermined period. The number of clocks is counted, the delimiter position of the transmitted packet is detected, the time information obtained by the carrier clock at the delimiter position is counted, and each data is recorded on the recording medium together with the video data and the audio data. .

The recording medium thus recorded can be reproduced by the reproducing apparatus according to the second aspect. The reproducing device reproduces the data in synchronization with the internal reference signal. When the carrier clock generating means generates a carrier clock according to the frequency type of the carrier clock, counts the number of carrier clocks in the reference signal period generated in each predetermined cycle, and when the count result reaches a predetermined value. A second reference signal is generated. Then, the phase difference between the reference signal and the second reference signal is detected, and the frequency of the reference signal generated by the reference signal generating means is changed so as to reduce the phase difference. Further, the video data and audio data reproduced by the reproducing means are stored in the storage means. Then, the number of carrier clocks generated from the carrier clock generation circuit is counted, and when the value of the time information obtained by the carrier clock at the packet break position is reached, a control signal is generated from the storage control means. The video and audio data stored in the storage means is read by the control signal and input to the input means.

According to a third aspect of the present invention, there is provided a recording apparatus, wherein a flag indicating a recording start position of video data and audio data is set.
It records on a recording medium similarly to the described recording device.

The recording medium thus recorded can be reproduced by the reproducing apparatus according to the fourth aspect. The reproducing device reproduces the data in synchronization with the internal reference signal. When the carrier clock generating means generates a carrier clock according to the frequency type of the carrier clock, counts the number of carrier clocks in the reference signal period generated in each predetermined cycle, and when the count result reaches a predetermined value. A second reference signal is generated. Then, the phase difference between the reference signal and the second reference signal is detected, and the frequency of the reference signal generated by the reference signal generating means is changed so as to reduce the phase difference. Further, the video data and audio data reproduced by the reproducing means are stored in the storage means. Then, the number of carrier clocks generated from the carrier clock generating circuit is counted, and when the value of the time information obtained by the carrier clock at the packet delimiter position is reached, the control signal is generated from the storage control means. At this time, if the flag indicating the recording start position is input, the count value of the carrier clock number is corrected to a predetermined value. The video and audio data stored in the storage means is read by the control signal and input to the input means.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. This embodiment will be described by taking a digital VTR which records and reproduces digital broadcasting such as ATV and DVB as a digital signal on a magnetic tape.

FIG. 1 shows a block diagram of a first embodiment of the recording apparatus of the present invention. The recording apparatus of this embodiment includes a tuner 101, a recording block 102 (recording means), a reference signal generation circuit 103, a carrier clock detection circuit (carrier clock detection means) 104, a packet delimiter detection circuit 105, a carrier clock counting block (carrier clock). Counting means) 106 and a second carrier clock counting block (second carrier clock counting means) 107.

The tuner 101 receives a broadcast wave of digital broadcasting, performs a predetermined process such as a demodulation process and an error correction process, and outputs an MPEG2 TS packet sequence 120 to the recording block 102. MPEG2 TS packet sequence 12
0 is video data or audio data compressed as described above. The MPEG2 TS packet sequence 120 is synchronized with the carrier clock 121 and is recorded in the recording block 102 without gaps.
Is output to. The reference signal generation circuit 103 generates a reference signal 122 that serves as a reference for the recording operation of the recording block 102 and outputs it to the recording block 102 and the carrier clock counting block 106. In this embodiment, the reference signal 12
Reference numeral 2 is a signal that rises at a cycle of 1.001 / 300 seconds. The time of 1.001 / 300 seconds is the time for the recording block 102 to form one track on the tape. That is, the recording block 102 records video data and audio data on the tape in synchronization with the reference signal 122. The carrier clock 121 includes a carrier clock counting block 106 and a second carrier clock counting block 1
07, the carrier clock detection circuit 104, and the recording block 102. Carrier clock detection circuit 104
Is the carrier clock 12 output from the tuner 101.
1 is input, the type of the frequency is detected, and the type data 123 is output to the recording block 102. The packet delimiter detection circuit 105 inputs the video data and audio data 120 transmitted from the tuner 101 in units of TS packets of MPEG2, detects the delimiter of each packet, and outputs the timing pulse 1 every time the delimiter is detected.
24 is output to the second carrier clock counting block 107.

The carrier clock counting block 106 is composed of a counter 110 and a register 111. The operation of the carrier clock counting block will be described with reference to FIG. The reference signal 122 is the counter 110 and the register 1
11 has been entered. The counter 110 counts the carrier clock 121 and outputs a count value 125 to the register 111. As shown in FIG. 2, the counter 110 is reset to 0 when the reference signal 122 rises and is incremented by 1 in synchronization with the carrier clock 121. In FIG. 2, when the reference signal 122 first rises, the count value 1
25 is reset from n to 1 and incremented by 1, and when it next rises, it is reset from m to 1. The register 111 has a count value 1 input from the counter 110.
25 is held when the reference signal 122 rises. The register 111 holds the value until the reference signal 122 rises next time. In FIG. 2, the register 111 holds the count value n when the reference signal 122 first rises, and holds the count value m when the reference signal 122 next rises. The count value 126 held by the register 111 is output to the recording block 102.

Second carrier clock counting block 107
Is composed of a counter 112 and a register 113. The operation of the second carrier clock counting block will be described with reference to FIG. The timing pulse 124 output from the packet delimiter detection circuit 105 is input to the register 113. Counter 112 is carrier clock 1
21 is counted, and the count value 127 is stored in the register 113.
Output to. As shown in FIG. 3, the counter 113 increments by 1 in synchronization with the carrier clock 121. Register 1
13 is the count value 12 input from the counter 112
7 and holds the count value 127 when the timing pulse 124 rises. The register 113 holds the value until the timing pulse 124 rises next time. In FIG. 3, the register 113 holds the count value q when the timing pulse 124 first rises, and holds the count value p when the timing pulse 124 next rises. The count value 128 held by the register 113 is output to the recording block 102.

The recording block 102 is a TS of MPEG2.
The packet string 120, the carrier clock frequency type data 123, the carrier clock count value 126 within the reference signal period, and the time information 128 obtained by the carrier clock at the packet separation position are multiplexed.
Recording is performed on the tape in synchronization with the reference signal 122 from the reference signal generation circuit 103. FIG. 4 shows a configuration example of the recording block 102. The recording block 102 includes the memories 401 and E.
It is composed of a CC circuit 402, a modulation circuit 403, and a control circuit 404. The memory circuit 401 changes the data rate for recording the MPEG2 TS packet sequence 120 input in synchronization with the carrier clock 121 in synchronization with the reference signal 122. The control circuit 404 uses the reference signal 1
A control signal for reading the MPEG2 TS packet sequence from the memory 401 is generated in synchronization with the memory 40.
Output to 1. A TS packet sequence is input from the memory 401 to the ECC circuit 402 in synchronization with the reference signal 122, the carrier clock frequency type data 123, the carrier clock count value 126 within the reference signal period, and the carrier at the packet delimiter position. The time information 128 obtained by the clock is also input. As described above, the data rate of the TS packet of MPEG2 is i (i ≦ 2
5) Mbps and the recording rate of this VTR is 25M
bps. The ECC circuit 402 generates dummy data to complement the difference in data rate. Also, ECC
The circuit 402 is a T of MPEG2 which is inputted with dummy data.
A parity code for error correction is added to the S packet sequence, the count value, and the time information and input to the modulation circuit 403. The modulation circuit 403 performs a predetermined modulation on the input data string and records it on the tape. Also, the reference signal 1
In order for the ECC circuit 402 and the modulation circuit 403 to perform predetermined processing in synchronism with 22, the control signals are generated by them. The control circuit 404 also controls the rotation of the rotary head and the tape feed speed.

In the recording apparatus of this embodiment, the type of frequency of the carrier clock 121 is detected and its type data 123 is detected.
Then, the number of carrier clocks 121 in one cycle period of the reference signal 122 is counted, and the number of clocks 126 of the carrier clock 121 in one cycle period and the time information 128 obtained by the carrier clock at the packet delimiter position are recorded in MPEG2. It is recorded on the tape together with the TS packet sequence.

An embodiment of a reproducing apparatus for reproducing the tape recorded by the VTR of the first embodiment of the recording apparatus of the present invention will be described. FIG. 5 shows a block diagram of the embodiment. The reproducing apparatus of this embodiment includes a reproducing block 501 (reproducing means), a decoder 502, a reference signal generating circuit 503 (reference signal generating means), a carrier clock generating circuit (carrier clock generating means) 504, a counter 505, a comparing circuit 506, Phase error detection circuit 507, memory 508, counter 509, memory control circuit (output control means) 510
It is composed of

The reproduction block 501 receives the reproduced digital signal, performs a predetermined demodulation process, corrects the error, and removes the dummy data added at the time of recording. The reference signal generation circuit 503 generates the reference signal 522 having the same cycle as that at the time of recording, and the reproduction block 501 reproduces the reproduced digital signal from the tape in synchronization with the reference signal 522. Reference signal 52
The period of 2 is 1.0, which is the same as the period of the reference signal 122 at the time of recording.
It is 01/300 seconds. The carrier clock frequency type data 523 reproduced by the reproduction block 501 is input to the carrier clock generation circuit 504, and the carrier clock 521 having a frequency corresponding to the type data 523 is generated. The carrier clock 521 generated by the carrier clock generation circuit 504 from the reproduction block 501.
In synchronization with, the MPEG2 TS packet sequence 520 is output.

The average data rate of only the MPEG2 TS packet sequence in the reproduced digital signal input to the reproduction block must be equal to the frequency of the carrier clock 521. Therefore, in the present embodiment, they are made equal by the following method.

The carrier clock 521 obtained from the carrier clock generation circuit 504 is input to the counter 505. The counter 505 also receives the carrier clock number 524 within the period of the reference signal reproduced from the tape. The counter 505 increments by 1 in synchronization with the carrier clock 521. Count value is playback count value 5
When it is equal to the value of 24, it is reset to 1. The count value 526 of the counter 505 is input to the comparison circuit 506. The comparison circuit 506 generates the second reference signal 527 when the count value 526 becomes 1, for example. The phase error detection circuit 507 detects the phase error between the reference signal 522 and the second reference signal 527, and detects the phase error 528 as the reference signal generation circuit 503.
Output to. The reference signal generation circuit 503 detects the phase error 52.
8 based on the reference signal 522 to reduce the phase error.
Increase or decrease the frequency of. By performing such feedback control, the reference signal 522 and the second reference signal 52
The phase error of 7 can always keep a small value. By such a method, the TS packet reproduced from the tape can be output at the same data rate as the TS packet input from the signal source at the time of recording.

FIG. 6 shows an example of the structure of the reproduction block 601. The reproduction block 501 includes a demodulation circuit 601, an ECC circuit 602, and a control circuit 603. The control circuit 603 controls the rotation speed of the rotary head in synchronization with the reference signal 522, and also controls the demodulation circuit 601 and the ECC circuit 6.
Generate a predetermined control signal for operation 02. Since the rotation speed of the rotary head is synchronized with the reference signal 522 under the control of the control circuit 603, the reproduced digital signal reproduced from the tape is synchronized with the reference signal 522.
The demodulation circuit 601 performs a predetermined demodulation process on the reproduced digital signal and outputs it to the ECC circuit 602. The data input to the ECC circuit 602 is input in the format as shown in FIG. The data transmission rate in FIG. 7B is about 25 Mbps which is the recording rate of the VTR.

This data string is a dummy data 702 added to the TS packet 701 of MPEG2 at the time of recording.
Is also added. The ECC circuit 602 corrects the reproduction error, removes the added dummy data 702, and
The G2 TS packet 701 is output to the memory 508.

Next, the MPEG2 T from the memory 508 is recorded.
The read timing of the S packet will be described. The carrier clock 521 generated by the carrier clock generation circuit 504 is input to the counter 509. Counter 5
To 09, time information 5 obtained by the carrier clock at the delimiter position of the packet reproduced from the tape
25 has also been entered. The counter 509 increments by 1 in synchronization with the carrier clock 521. Since the time information 525 represents an absolute time, the counter 509 counts the difference between the time information 525 sent immediately before and the current time information 525. When the count value reaches the difference value between the current time information 525 and the previous time information 525, the count value is reset to 1. Count value 5 of the counter 509
29 is input to the memory control circuit 510. In the memory control circuit 510, when the counter value 529 becomes 1, for example,
A control signal 530 for controlling the reading of the MPEG2 TS packet from the memory 508 is output to the memory 508.

The memory 508 uses the carrier clock 521 generated by the carrier clock generation circuit 504 and the control signal output from the memory control circuit to cause MPE.
The TS packet 531 of G2 is output to the decoder 502 in synchronization with the carrier clock 521. Decoder 502
Decodes video and audio TS packets to restore video and audio signals.

Next, a second embodiment of the recording apparatus will be described. FIG. 8 shows a block diagram of a second embodiment of the recording apparatus of the present invention. The recording apparatus of this embodiment includes a tuner 101, a recording block 102 (recording means), a reference signal generation circuit 103, a carrier clock detection circuit (carrier clock detection means) 104, a packet delimiter detection circuit 105, a carrier clock counting block (carrier clock). The counting means) 106 and the second carrier clock counting block (second carrier clock counting means) 107 are the same as in the first embodiment, and a recording start position detection circuit (recording start position detection means) 801 is provided. Is different.

In the first embodiment of the recording apparatus, since the broadcast program is continuously recorded, the tuner 101 stores the data output from the tuner 101 in the MPEG2 TS packet sequence 120 at all times within a predetermined interval. The value of the time information 128 recorded and obtained by the carrier clock at the packet delimitation position also increases at a substantially constant rate. However, when the time information 128 changes greatly due to connection and the like, in the reproducing apparatus for reproducing the tape recorded by the VTR of the first embodiment, while the second carrier clock counting block 107 is counting the number of carrier clocks. To
The memory 508 overflows.

Therefore, in this embodiment, the recording start position detection circuit 80 is added to the configuration of the first embodiment relating to the recording apparatus.
It is configured by adding 1. Recording start position detection circuit 80
In No. 1, the signal 820 indicating the recording start is input from the system microcomputer, and the recording start flag 821 is set to the recording block 10.
Output to 2.

In the recording block 102, the MPEG2 T
The S packet sequence 120, the carrier clock frequency type data 123, the carrier clock count value 126 within the reference signal period, the time information 128 obtained by the carrier clock at the packet break position, and the recording start flag 821 are multiplexed. , Reference signal generation circuit 103
It is recorded on the tape in synchronization with the reference signal 122 from.

Next, the V of the second embodiment relating to the recording apparatus will be described.
The second regarding the reproducing device for reproducing the tape recorded in TR
An example will be described. FIG. 9 shows a block diagram of the embodiment. The reproducing apparatus of this embodiment includes a reproducing block 501, a decoder 502, a reference signal generating circuit 503 (reference signal generating means), a carrier clock generating circuit (carrier clock generating means) 504, a counter 505, a comparing circuit 506,
Phase error detection circuit 507, memory 508, counter 50
9. The memory control circuit (output control means) 510 is the same as that of the first embodiment, and is composed of a count value correction circuit (output time correction means) 901.

In this embodiment, a count value correction circuit 901 is added to the structure of FIG. When a tape having data discontinuity such as connection removal is reproduced and the tape approaches the position, a recording start flag 920 indicating the connection removal position is reproduced by the reproduction block 501 and input to the count value correction circuit 901. It At the same time, the time information 525 is also reproduced in the reproduction block, but its value has changed greatly from the value of the position on the tape before connection and greatly changed. Since the change is large, as described above, the memory 508 overflows while the counter 509 counts the carrier clock 521 until the value of the time information 525 is reached. To prevent this, the count value correction circuit outputs the correction value to the counter 509 so as to correct the count number of the first carrier clock 521 after connection in the counter 509. Since the time information 525 represents the absolute time after that, as in the first embodiment, the counter 509 only needs to count the difference between the time information 525 sent immediately before and the current time information 525. .

In the above description of the embodiment of the present invention, the tuner inside the recording apparatus receives the broadcast wave,
Although the apparatus for recording the TS packet of MPEG2 has been described as an example, the output means is not from the tuner, but rather from the tuner.
Even when a circuit for inputting an MPEG2 TS packet as a digital signal from another device and outputting the signal to the inside is equipped, the same effect can be obtained by using the recording device of the present invention. Further, in the description of the embodiments of the present invention, a device that decodes MPEG2 TS packets by a decoder inside the playback device and restores a video signal and an audio signal has been described as an example. Even when the apparatus is equipped with a circuit for outputting MPEG2 TS packets as a digital signal, the same effect can be obtained by using the reproducing apparatus of the present invention.

In the description of this embodiment, the T of MPEG2 is used.
Although the S packet sequence has been described as an example, it goes without saying that a data sequence compressed by another method can also be recorded and reproduced by using the recording device and the reproducing device of the present invention.

The cycle of the reference signal in the recording apparatus and the reproducing apparatus of this embodiment is 1.001 / 300 seconds, but this cycle is just a cycle for synchronizing the VTR. . Therefore, the cycle of the reference signal is VT
Other cycles may be used as long as R can be synchronized. For example, 1/25 seconds, about 1/30 seconds, etc. can be considered.

Further, although the clock counting means in this embodiment counts the number of bits of the TS packet of MPEG2 within one cycle period of the reference signal as the number of clocks from the tuner, it counts the number of bytes or the number of TS packets. However, a method of recording on tape is also conceivable.

[0048]

As described above, when data is recorded by the recording device of the invention described in claim 1 and the tape is reproduced by the reproducing device of the invention described in claim 2, the data output from the tuner of the recording device is recorded. Since the packet format and the output timing of the packet format of the data reproduced from the reproduction block at the time of reproduction can be made the same, the decoder of the reproducing apparatus can accurately restore the video data and the audio data.

Further, if data is recorded by the recording apparatus of the third aspect of the invention and the tape is reproduced by the reproducing apparatus of the fourth aspect of the invention, even if there is a discontinuity in the data due to joining or the like, the memory No overflow occurs, data can be accurately output even at the recording start position, and the memory capacity can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram of a first embodiment of a recording apparatus of the present invention.

FIG. 2 is an explanatory diagram of an operation of a first count block according to the recording apparatus of the present invention.

FIG. 3 is an explanatory diagram of an operation of a second count block according to the recording apparatus of the present invention.

FIG. 4 is a block diagram showing a configuration example of a recording block according to a recording apparatus of the present invention.

FIG. 5 is a block diagram of an embodiment of the reproducing apparatus of the present invention corresponding to the first embodiment of the recording apparatus of the present invention.

FIG. 6 is a block diagram showing a configuration example of a playback block according to the playback device of the present invention.

FIG. 7 is an explanatory diagram of a data format inside the recording apparatus and the reproducing apparatus of the embodiment.

FIG. 8 is a block diagram of a second embodiment relating to the recording apparatus of the present invention.

FIG. 9 is a block diagram of an embodiment of the reproducing apparatus of the present invention corresponding to the second embodiment of the recording apparatus of the present invention.

[Explanation of Codes] 101 Tuner 102 Recording Block 103 Reference Signal Generation Circuit 104 Carrier Clock Detection Circuit 105 Packet Separation Detection Circuit 106 Carrier Clock Counting Block 107 Second Carrier Clock Counting Block 110 Counter 111 Register 112 Counter 113 Register 120 MPEG2 TS Packet Column 121 Carrier clock 122 Reference signal 123 Carrier clock frequency type data 124 Timing pulse 125 Count value 126 Number of carrier clocks in reference signal period 127 Count value 128 Time information 401 Memory 402 ECC circuit 403 Modulation circuit 404 Control circuit 501 Playback Block 502 Decoder 503 Reference signal generation circuit 504 Carrier clock generation circuit 505 Counter 506 Comparison circuit 507 Phase error detection circuit 508 Memory 509 Counter 510 Memory control circuit 520 MPEG2 TS packet sequence 521 Carrier clock 522 Reference signal 523 Carrier clock frequency type data 524 Number of carrier clocks in reference signal period 525 Time information 526 Count value 527 Second reference signal 528 Phase error 529 Count value 530 Control signal 531 MPEG2 TS packet sequence 601 Demodulation circuit 602 ECC circuit 603 Control circuit 701 MPEG2 TS packet 702 Dummy data 801 Recording start position detection circuit 820 Indicates recording start Signal 821 Recording start flag 901 Count value correction circuit 920 Recording start flag 921 Correction value

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hidetoshi Takeda 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (4)

[Claims] 1. A carrier clock detecting means for detecting a frequency type of a carrier clock for carrying packetized data, a first carrier clock counting means for counting the number of carrier clocks within a predetermined period, and the packet. Second carrier clock counting means for counting time information obtained by the carrier clock at the delimiter position, the packetized data, information indicating the type of the frequency, the number of carrier clocks, and the time information. A recording apparatus comprising recording means for recording on a recording medium. 2. Reproducing means for reproducing data recorded on a recording medium, information indicating the type of carrier clock frequency, the number of carrier clocks within a predetermined period, and time information, and the carrier clock. Carrier clock generation means for generating a carrier clock according to the frequency type, reference signal generation means for generating a reference signal equal to the predetermined period according to the number of carrier clocks, and an output for controlling the output of the data according to the time information. A reproducing apparatus comprising control means. 3. A carrier clock detecting means for detecting a frequency type of a carrier clock for carrying packetized data, a first carrier clock counting means for counting the number of carrier clocks within a predetermined cycle, and the packet. Second carrier clock counting means for counting time information obtained by the carrier clock at the delimiter position, recording start position detecting means for detecting a recording start position of the packetized data, the packetized data, and A recording device comprising: recording means for recording information indicating a frequency type, the number of carrier clocks, the time information, and a flag indicating the recording start position on a recording medium. 4. Reproduction of data recorded on a recording medium, information indicating a frequency type of a carrier clock, the number of carrier clocks within a predetermined period, time information, and a flag indicating a recording start position. Reproducing means, a carrier clock generating means for generating a carrier clock according to the type of the frequency of the carrier clock, a reference signal generating means for generating a reference signal equal to the predetermined period according to the number of carrier clocks, and the time information. A reproducing apparatus comprising: output control means for controlling the output of the data; and output time correction means for correcting the output time of the data at the recording start position by the flag.