JP3515289B2 - Transmission data recording device and transmission data reproducing device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission data recording device and a transmission data reproducing device for recording and reproducing data that has been compression-encoded by the MPEG system and transmitted.

[0002]

2. Description of the Related Art When transmitting data such as video that is compression-encoded by the MPEG method or the like and packetized, dummy data is inserted in order to match the data transmission rate with the original rate defined by the system. . Instead of inserting the dummy data, another data may be inserted, that is, effective data may be multiplexed and transmitted.

In this case, data is transmitted at a rate lower than the rate at which it should be actually transmitted. On the contrary, the data may be transmitted in a short time by transmitting at a rate higher than the original transmission rate.

From such a multiplexed stream, data transmitted at a rate different from the original transmission rate is extracted and recorded in a VCR (video cassette recorder) or the like.
When the reproduced data is input to the decoding device for decoding and reproduction, the following problems occur. For example, if the data is transmitted at a rate higher than the original transmission rate, for example, twice, the data for one hour is recorded and reproduced in 30 minutes, and the data is on time as intended by the encoding side. Cannot be decoded and reproduced by the decoding device. Further, when data is transmitted at a rate lower than the original transmission rate, for example, 1/2, it takes 2 hours to record and reproduce 1 hour's worth of data. It becomes impossible for the decoding device to decode and reproduce the data on time.

[0005]

As described above, in the conventional transmission data recording apparatus and transmission data reproducing apparatus, the data transmitted at a rate different from the original transmission rate is recorded and reproduced, and the reproduced data is reproduced. When transmitted to the decoding device, there is a problem that the data cannot be correctly decoded and reproduced according to the time intended by the encoding side.

The present invention is for solving such a problem, and records data transmitted at a rate lower than the original transmission rate included in a stream of multiplexed compression-encoded data, It is an object of the present invention to provide a transmission data recording device which can correctly decode and reproduce the reproduced data at the time of reproduction by the decoding device at the time intended by the encoding side.

Further, the present invention is to solve such a problem, and is for data transmitted and recorded at a rate higher than the original transmission rate contained in a stream of multiplexed compression-encoded data. It is an object of the present invention to provide a transmission data reproducing device which can correctly decode and reproduce the reproduced data at the time of reproduction by the decoding device at the time intended by the encoding side.

[0008]

In order to achieve the above object, a transmission data recording apparatus according to the present invention has a recording unit for recording data on a recording medium at a first rate as described in claim 1. And is compressed and encoded at a second rate lower than the first rate, and when OPCR information and PCR information are respectively added and multiplexed with other data, they are multiplexed at a third rate lower than the second rate. The input means for inputting the multiplexed stream containing the selected low-rate transmission data, and the OP from the low-rate transmission data in the multiplexed stream input to the input means.
The OPCR extraction means for extracting the CR information is compared with the latest OPCR information extracted by the OPCR extraction means and the last OPCR information in the recorded low rate transmission data to obtain the difference, and the difference is not less than a predetermined value. If it is, the recording unit is controlled so that the recording operation is performed for a predetermined time, and the recording operation is interrupted.
And a control means for performing the operation intermittently.

In the transmission data recording apparatus of the present invention, the recording operation of the recording unit is intermittently performed to physically and continuously record the low-rate transmitted data on the recording medium. The reproduced data can be decoded and reproduced by the decoding device at the time intended by the encoding side. For example, even if data for n hours is transmitted at a low rate over n hours or more, it can be recorded and reproduced as the original data for n hours.

Further, as described in claim 2, the transmission data recording apparatus of the present invention comprises a recording section for recording data on a recording medium at a first rate, and a second section lower than the first rate. Compression-encoded at rate, OPCR information and PC
Input means for inputting a multiplexed stream containing low-rate transmission data multiplexed at a third rate lower than the second rate when R information is added and multiplexed with other data; PCR rewriting means for rewriting the PCR information added to the low rate transmission data in the multiplexed stream input to the means to a value corresponding to the case where the low rate transmission data is transmitted at the first rate. And dummy data is inserted into the low-rate transmission data so that the rate of the low-rate transmission data whose PCR information has been rewritten by the PCR rewriting means matches the first rate, and the dummy data is output to the recording unit as recording data. The dummy data inserting means and the low-rate transmission data in the multiplexed stream input to the input means.
OPCR extraction means for extracting CR information, and the OPCR
The latest OPCR information extracted by the extraction means and the last OPCR information in the recorded low-rate transmission data are compared to obtain the difference, and when the difference is equal to or more than a predetermined value, the recording operation is performed for the predetermined time. And a control unit for controlling the recording unit to perform the recording operation intermittently .

In the transmission data recording apparatus of the present invention, the recording operation of the recording unit is intermittently performed to physically and continuously record the low-rate transmitted data on the recording medium, and the low-rate transmitted data is recorded. P rewritten when multiplexing
By rewriting the CR information to a value corresponding to the case where the data was transmitted at the original transmission rate (first rate), the reproduced data can be reproduced by the decoding device at the time intended by the encoding side during the reproduction. It becomes possible to correctly decode and reproduce.

Further, the transmission data reproducing apparatus of the present invention is
As described in claim 3, the OPCR information and the PCR are compressed and encoded at a second rate lower than the first rate.
From a recording medium on which a multiplexed stream containing high-rate transmission data, which is added with information and multiplexed with other data at a third rate higher than the second rate, is recorded at the first rate, A reproduction unit that reproduces the high-rate transmission data at the first rate, an OPCR extraction unit that extracts the OPCR information from the high-rate transmission data reproduced by the reproduction unit, and counts up at a predetermined cycle. Counter means for outputting the value of PCR information added to the high-rate transmission data when the high-rate transmission data is transmitted at the first rate.
The latest OPCR information extracted by the OPCR extraction means is compared with the output value of the counter means to obtain a difference, and when the difference is equal to or more than a predetermined value, the reproduction unit is stopped so as to stop the reproduction operation. Controls playback operation intermittently
And a control means for performing the above.

In the transmission data reproducing apparatus of the present invention, the reproduction operation of the reproducing unit is intermittently executed so that the reproduction data of the data recorded at the high rate transmission is reproduced by the decoding apparatus at the time intended by the encoding side. It becomes possible to correctly decode and reproduce. For example, even if data for n hours is transmitted and recorded in a time less than n hours, it can be reproduced as the original data for n hours at the time of reproduction.

Further, the transmission data reproducing apparatus of the present invention is
As described in claim 4, OPCR information and PCR are compression-encoded at a second rate lower than the first rate.
From a recording medium on which a multiplexed stream containing high-rate transmission data, which is added with information and multiplexed with other data at a third rate higher than the second rate, is recorded at the first rate, A reproduction unit that reproduces the high-rate transmission data at the first rate, an OPCR extraction unit that extracts the OPCR information from the high-rate transmission data reproduced by the reproduction unit, and counts up at a predetermined cycle. Counter means for outputting the value of PCR information added to the high-rate transmission data when the high-rate transmission data is transmitted at the first rate.
A PCR rewriting unit that rewrites the PCR information added to the high-rate transmission data reproduced by the reproducing unit with an output value of the counter unit, and the PCR information in which the PCR information is rewritten by the PCR rewriting unit. Dummy data insertion means for inserting dummy data into the high-rate transmission data so as to match the rate of the rate transmission data with the first rate and outputting it as final reproduction data; and the latest data extracted by the OPCR extraction means. O
The PCR information and the output value of the counter means are compared to obtain the difference, and when the difference is equal to or more than a predetermined value, the reproducing unit is controlled to stop the reproducing operation, and the reproducing operation is performed.
And a control means for intermittently performing .

In the transmission data reproducing apparatus of the present invention, the reproducing operation of the reproducing unit is intermittently executed, and the PCR information of the reproduction data of the data recorded at high rate is recorded at the original transmission rate (first rate). By rewriting to a value corresponding to when the data is transmitted, the reproduced data can be correctly decoded and reproduced by the decoding device at the time intended by the encoding side.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments for carrying out the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the structure of a transmission data recording apparatus according to an embodiment of the present invention.

This transmission data recording device records, for example, data transmitted from the multiplexed stream at a rate lower than the original transmission rate, and the reproduction data is intended by the decoding device on the encoding side. It is designed so that decoding and reproduction can be performed on time.

The multiplexed stream will be described with reference to FIG. The transmission rates of the data A and B are higher than that of the data C. Each of the data A, B, and C has a fixed-length packet as a constituent element. In the figure, the difference in packet length among the data A, B, and C represents the difference in data rate. A header area (a shaded portion) is provided at the beginning of the packet.

In the header area of at least some of the packets, OPCR (Original), which is fixed time information before multiplexing, which indicates a data arrival time when a clock that counts up at a specific clock (system clock) is used as a reference. P
rogram clock reference) and PCR (Program Clock Referenc) which is time information rewritten by multiplexing.
e) is described. In addition, P before multiplexing with OPCR
The CR values are the same. When the data A, B, and C are multiplexed and transmitted as a multiplexed stream through a transmission line having a high transmission rate, the data arrival time of each data packet is different from that before the multiplexing. Therefore, PCR is rewritten at the time of multiplexing. Note that OPCR is not used in the decryption device,
Neither is it rewritten. When decoding the data, the decoding device sets / calibrates the frequency of the system clock to a value intended by the encoding side from the PCR and its arrival time, and decodes the data using this system clock.

Although a dummy packet is inserted in FIG. 2, other valid video data may be inserted in place of this dummy packet. In this case, data will be transmitted at a low rate different from the original data rate.

The transmission data recording apparatus of this embodiment inputs low-rate data extracted from such a multiplexed stream from the input terminal 1. The low-rate data input from the input terminal 1 is once held in the input stage buffer 2 and is also input to the OPCR extraction unit 3. OPCR
The extraction unit 3 extracts the OPCR from the input data and always sends the latest OPCR value to the recording operation control unit 4. The recording operation control unit 4 controls the recording operation of the VCR intermittently based on the value of the OPCR, the control of reading data from the input stage buffer 2,
Control of the counter 6 in the recording data creation unit 5 and the like are performed.

Next, the intermittent recording operation control of the VCR and the data reading control from the input stage buffer 2 by the recording operation controller 4 will be described.

The recording operation control unit 4 stores the latest OPCR value input from the OPCR extraction unit 3 and the last OPCR value in the data intermittently recorded in the VCR with one recording operation time as Tr. And the difference is obtained. Each time the operation control unit 4 determines that the above difference is equal to or greater than Tr, the operation control unit 4 controls the VCR so as to cause the VCR to perform the recording operation once (for the Tr time), and the VCR recording period is the input stage. Record data from buffer 2 Data creation unit 5
Control to read out. When the VCR completes one recording operation, the tape running is stopped until the next command is issued from the operation control unit 4. Here, since the data transmission rate is lower than the VCR recording rate, a waiting time corresponding to the difference between the values of the respective rates occurs before the next recording operation is started. Therefore, the VCR recording operation is intermittently executed.

Next, the recording data creating section 5 will be described.

The recording data creation unit 5 includes a recording operation control unit 4
Under the control of 1., a counter 6 that counts up in a constant cycle only for the recording period of the VCR is provided. The counter 6 is set to have a count-up period value so as to output a count value that matches the PCR value added to the original transmission rate data.

The data read from the input stage buffer 2 only during the VCR recording period is stored in the PC in the recording data creating section 5.
It is input to the R rewriting unit 7 and also to the second OPCR extraction unit 8. The PCR rewriting unit 7 rewrites the PCR in the input data with the current count value of the counter 6. On the other hand, the second OPCR extraction unit 8 extracts the OPCR from the data read from the input stage buffer 2 and sends it to the comparison unit 9. The comparator 9 compares this OPCR with the current count value of the counter 6 and notifies the packet selector 10 of the result.

The packet selector 10 outputs the output of the dummy packet generator 11 and P based on the comparison result of the comparator 8.
One of the outputs of the CR rewriting unit 7 is selected and transmitted to the recording data input unit of the VCR. That is, the packet selector 10 selects the dummy packet generated by the dummy packet generation unit 11 when the count value is smaller than the value of OPCR and transmits it to the VCR. While the dummy packet is selected, the PCR rewriting unit 7 holds the data after the PCR rewriting, and repeats updating the PCR with a new count value each time the counter 6 is counted up.
Then, when the count value exceeds the value of OPCR, the packet selector 10 causes the PCR rewriting unit 7
Output is selected and transmitted to the VCR.

PC based on the count value of the counter 6
The R may be rewritten only once when the packet selector 10 selects the output of the PCR rewriting unit 7. A specific example of the above-described recording data creation processing is shown in FIG.
Shown in.

Here, for the sake of simplicity, it is assumed that the PCR information is recorded at the beginning of the packet and the OPCR information is recorded next, and the length of the packet is short.
A method of creating print data will be described.

FIG. 3A shows the count value during the recording operation, and the counting operation is stopped during the period when the recording operation is stopped. (B) shows PCR and OPCR of the packet output from the buffer.
The information matches the count value because it controls the recording operation and the counter operation. Since the ΡCR information is transmitted at a rate different from the actual rate, it has a different value from the OPCR. If you are transmitting at a low rate,
The PCR value Ν of packet 1 is larger than the OPCR value M (because it was transmitted at a late time). Also, the subsequent packets are Ν + p, Ν + q because they are transmitted using the vacant area. p, q
Depends on the position transmitted.

[0032] (b) shows the packets read from the buffer, the value of OPCR packet 2 is greater than the count value, since the comparing unit 9 selects the dummy packets at a packet selector 10, PCR The rewriting unit 7 does not output the packet, and does not read the packet from the buffer after the packet 2.

(C) shows the output data of the packet selector 10. As described above, the packet 2 is a dummy packet. Packet 3 has OPCR value Μ + 8
And is output because it is smaller than the count value Μ + 12. At this time, the PCR rewriting unit 7 rewrites the counter value Μ + 12 at this time as PCR and outputs it. The output data of the packet selector 10 is V as recording data.
Recorded in CR.

As described above, in the transmission data recording apparatus of this embodiment, the PCR of the data transmitted at the low rate is rewritten to a value corresponding to the case where the data is transmitted at the original transmission rate, and the VCR recording operation is performed. Is intermittently executed to physically and continuously record the data transmitted at the low rate on the recording medium of the VCR, so that the decoding device encodes the reproduced data obtained by the original reproducing operation of the VCR. Therefore, it is possible to correctly decode and reproduce according to the intended time.

Next, the transmission data reproducing apparatus according to the present invention will be described. The transmission data reproducing device of this embodiment is
Data contained in the multiplexed stream and having a higher rate than the original transmission rate is recorded in the VCR so that the reproduced data can be decoded and reproduced by the decoding device at the time intended by the encoding side during reproduction. Is.

FIG. 4 shows the configuration of this transmission data reproducing apparatus. It is assumed that the VCR has recorded therein data having a higher rate than the original transmission rate extracted from the multiplexed stream. The reproduction data of the VCR is input from the input end 21, is temporarily held in the input stage buffer 22 and is OP
It is input to the CR extraction unit 23. The OPCR extraction unit 23 extracts the OPCR from the input data and reproduces the OPCR.
Send to 4.

On the other hand, the data accumulated in the input stage buffer 22 is sequentially input to the PCR rewriting unit 27 in the reproduction data creating unit 25 and the second OPCR extracting unit 28. The PCR rewriting unit 27 rewrites the PCR in the input data with the count value of the counter 26. This counter 26 always counts up at a constant cycle,
It is used as PCR information used in the decoding device. The count value is output to the PCR rewriting unit 27 and the reproduction operation control unit 24.

On the other hand, the second OPCR extraction unit 28 extracts the OPCR from the input data and introduces it into the comparison unit 29. The comparison unit 29 compares the OPCR extracted by the second OPCR extraction unit 28 with the count value of the counter 26, and notifies the packet selector 30 of the result. The packet selector 30 selects either the output of the dummy packet generation unit 31 or the output of the PCR rewriting unit 27 based on the comparison result of the comparison unit 28, and transmits it to the decoding device. That is, when the count value is smaller than the OPCR value, the packet selector 30 determines that the dummy packet generation unit 31
The generated dummy packet is selected and transmitted to the decoding device. While the dummy packet is selected, the PCR rewriting unit 27 holds the data after the PCR rewriting, and repeats updating the PCR with a new count value each time the counter 26 counts up. Then, when the count value becomes equal to or larger than the value of OPCR, the output of the PCR rewriting unit 27 is selected by the packet selector 30 and transmitted to the decoding device.

P based on the count value of the counter 26
The CR rewriting may be performed only once when the packet selector 30 selects the output of the PCR rewriting unit 27.

Next, a method of creating reproduction data will be described with reference to FIG.

FIG. 5A shows the count value of the counter 26. This counter is always operating regardless of the VCR reproducing operation. (B) shows the ΡCR and OOCR of the packet output from the buffer 22. PCR
Since the information is transmitted at a rate different from the actual rate, it has a different value from the OPCR. When transmitted at a high rate, the value N of ΡCR of packet 1 is
The value is smaller than the OPCR value M (because it was transmitted at an early time). Further, the subsequent packets are multiplexed and sequentially transmitted, so that they are Ν + p and Ν + q. p and q depend on the transmitted position.

(B) shows a packet read from the buffer, and the value of OCR in packet 2 is OCR.
Since the value of is larger than the count value, the comparison unit 29 selects the dummy packet with the packet selector 30, so the PCR rewriting unit 27 does not output the packet, and after the packet 2, the packet is read from the buffer. Not not.

(C) shows the output data of the packet selector 10. As described above, the packet 2 is a dummy packet. Packet 3 has OPCR value Μ + 8
Is output because it is smaller than the count value Μ + 12. At this time, the PCR rewriting unit 27 rewrites the value M + 12 of the counter at this time as PCR and outputs it. The output data of the packet selector 30 is output to the decoding device as reproduction data. The reproduction operation control unit 24
The latest OPCR input from the CR extraction unit 23 is compared with the count value of the counter 26, and when the difference exceeds a predetermined value, the VCR is controlled so that the VCR reproduction operation is stopped.

As described above, in the transmission data reproducing apparatus of the present embodiment, the P of data having a rate higher than the original transmission rate is used.
By rewriting CR to a value corresponding to the case where data is transmitted at the original transmission rate and by intermittently executing the reproduction operation of the VCR, the reproduction device of the VCR is intended by the encoding device on the encoding side. It becomes possible to perform decoding and reproduction on time.

In the above embodiment, the VCR (video cassette recorder) is used as the recording / reproducing apparatus for the recording medium, but the present invention is not limited to this. For example, the recording operation and the reproducing operation of the recording / reproducing apparatus using the disk recording medium may be controlled to be performed intermittently.

[0046]

As described above, according to the transmission data recording apparatus of the present invention, the data transmitted at a rate lower than the original transmission rate included in the multiplexed compressed and encoded data stream is recorded. Then, during reproduction, the reproduction data can be correctly decoded and reproduced by the decoding device according to the time intended by the encoding side.

Further, according to the transmission data reproducing apparatus of the present invention, at the time of reproducing the data transmitted and recorded at a rate higher than the original transmission rate included in the multiplexed compressed and encoded data stream, The reproduced data can be correctly decoded and reproduced by the decoding device according to the time intended by the encoding side.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a transmission data recording device according to the present invention.

FIG. 2 is a diagram for explaining a multiplexed stream containing low-rate transmission data recorded in the transmission data recording apparatus of FIG. 1 and time information therein.

FIG. 3 is a diagram showing a process of a recording data creation unit of FIG.

FIG. 4 is a block diagram showing a configuration of a transmission data reproducing device according to the present invention.

5 is a diagram showing a process of a reproduction data creation unit in FIG.

[Explanation of symbols]

2 ... Input stage buffer 3 ... OPCR extraction unit 4 ... Recording operation control unit 5: Recorded data creation section 6 ... Counter 7 ... PCR rewrite unit 8 ... Second OPCR extraction unit 9 ………… Comparison section 10 ... Packet selector 11 ... Dummy packet generator 22 ... Input stage buffer 23 ... OPCR extraction unit 24. Reproduction operation control unit 25: Playback data creation section 26 ... Counter 27 ... PCR rewriting unit 28 ... Second OPCR extraction unit 29 …… Comparison section 30 ... Packet selector 31 ... Dummy packet generator

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Michihiro Fukushima 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Inside the Multimedia Technology Research Center, Toshiba Corporation (72) Yoshihisa Sakazaki Shinsugita-cho, Isogo-ku, Yokohama, Kanagawa Toshiba Corporation Multimedia Technology Research Center (56) Reference JP-A-8-297922 (JP, A) JP-A-8-195072 (JP, A) JP-A-9-139914 (JP, A) JP-A-10- 23370 (JP, A) JP-A-8-340514 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G11B 20/10 H04N 5/92

Claims (4)

(57) [Claims] 1. A recording unit for recording data on a recording medium at a first rate, and compression coding at a second rate lower than the first rate, adding OPCR information and PCR information to each other Input means for inputting a multiplexed stream containing low-rate transmission data multiplexed at a third rate lower than the second rate when multiplexed with the data; and, in the multiplexed stream input to the input means, OPC for extracting the OPCR information from the low rate transmission data
R extraction means, latest OPCR information extracted by the OPCR extraction means, and the last OPC in the recorded low rate transmission data
Control means for comparing the R information to obtain the difference, and when the difference is equal to or more than a predetermined value, the recording unit is controlled to perform the recording operation for the predetermined time to intermittently perform the recording operation. A transmission data recording apparatus comprising: 2. A recording unit for recording data on a recording medium at a first rate, and compression coding at a second rate lower than the first rate, adding OPCR information and PCR information to each other Input means for inputting a multiplexed stream containing low-rate transmission data multiplexed at a third rate lower than the second rate when multiplexed with the data; and, in the multiplexed stream input to the input means, PCR rewriting means for rewriting the PCR information added to the low rate transmission data to a value corresponding to the case where the low rate transmission data is transmitted at the first rate; and PCR information by the PCR rewriting means. Is written in the recording unit by inserting dummy data into the low rate transmission data so that the rate of the rewritten low rate transmission data matches the first rate. And dummy data insertion means for outputting as data, OPC extracting the OPCR information from the low rate transmission data multiplexed stream inputted to the input means
R extraction means, latest OPCR information extracted by the OPCR extraction means, and the last OPC in the recorded low rate transmission data
Control means for comparing the R information to obtain the difference, and when the difference is equal to or more than a predetermined value, the recording unit is controlled to perform the recording operation for the predetermined time to intermittently perform the recording operation. A transmission data recording apparatus comprising: 3. A second rate lower than the first rate is compression-coded, OPCR information and PCR information are added respectively, and multiplexed with other data at a third rate higher than the second rate. From the recording medium on which the multiplexed stream containing the recorded high-rate transmission data is recorded at the first rate,
A reproduction unit that reproduces the high-rate transmission data at the first rate, an OPCR extraction unit that extracts the OPCR information from the high-rate transmission data reproduced by the reproduction unit, and counts up at a predetermined cycle. , Counter means for outputting the value of PCR information added to the high-rate transmission data when the high-rate transmission data is transmitted at the first rate, and the latest extracted by the OPCR extracting means. OPCR information and the output value of the counter means are compared to obtain the difference, and when the difference is equal to or more than a predetermined value, the reproducing unit is controlled to stop the reproducing operation and the reproducing operation is intermittently performed. Target
And a control means for controlling the transmission data reproducing apparatus. 4. The data is compressed and encoded at a second rate lower than the first rate, OPCR information and PCR information are respectively added, and multiplexed with other data at a third rate higher than the second rate. From the recording medium on which the multiplexed stream containing the recorded high-rate transmission data is recorded at the first rate,
A reproduction unit that reproduces the high-rate transmission data at the first rate, an OPCR extraction unit that extracts the OPCR information from the high-rate transmission data reproduced by the reproduction unit, and counts up at a predetermined cycle. , Counter means for outputting a value of PCR information added to the high-rate transmission data when the high-rate transmission data is transmitted at the first rate, and the reproduction section reproduced the reproduction section. PCR rewriting means for rewriting the PCR information added to the high-rate transmission data with the output value of the counter means; and a rate of the high-rate transmission data in which the PCR information is rewritten by the PCR rewriting means. Insert dummy data into the high-rate transmission data so as to match the rate of 1 and output as final reproduction data The dummy data insertion means and the latest OPCR information extracted by the OPCR extraction means and the output value of the counter means are compared to obtain the difference, and when the difference is equal to or more than a predetermined value, the reproduction operation is stopped. The playback unit is controlled so that the playback operation is intermittently performed.
And a control means for controlling the transmission data reproducing apparatus.