JPH056507A - Digital information signal dubbing system - Google Patents

Abstract

PURPOSE:To evade a dubbing of a digital information signal deteriorated in quality by stopping the dubbing at the time of detecting an error which could not be corrected in the error corrected information signal. CONSTITUTION:The dubbing is performed by supplying a regenerative digital information signal from a magnetic tape reproducing device (reproducing side digital VTR) 11 to a magnetic tape recording device (recording side digital VTR) 18. In the magnetic tape reproducing device 11, the regenerative digital information signal is error-corrected, and when an error which could not be corrected in the corrected digital information signal is detected, the dubbing is stopped, and also magnetic tapes 1 and 17 loaded into the magnetic tape producing device 11 and the magnetic tape recording device 18 respectively are rewound by a prescribed amt., and afterward, the dubbing is resumed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dubbing system for digital information signals.

[0002]

2. Description of the Related Art In a conventional digital video signal dubbing method in which a playback digital video signal from a playback side digital VTR is supplied to a recording side digital VTR for dubbing, the playback side digital VTR has a playback digital video signal. The video signal is error-corrected, and if the error-corrected playback digital video signal contains an error that cannot be corrected, the error-corrected playback digital video signal is corrected by interpolation or the like. rear,
It was supplied to the recording side digital VTR for dubbing.

[0003]

In the conventional digital video signal dubbing method, when the error-corrected reproduced digital video signal from the reproduction side digital VTR is supplied to the recording side digital VTR and dubbed, This error-corrected digital video signal causes deterioration of image quality, and thus has a disadvantage that it is not preferable.

In view of the above point, the present invention, in the dubbing method of a digital information signal, which is adapted to supply the reproduced digital information signal from the magnetic tape reproducing apparatus to the magnetic tape recording apparatus to perform the dubbing, deteriorate the signal quality. The present invention intends to propose a device which can prevent the digital information signal from being dubbed as much as possible.

[0005]

According to a first aspect of the present invention, a reproduced digital information signal from a magnetic tape reproducing device 11 is supplied to a magnetic tape recording device 18 for dubbing. In the dubbing method, the magnetic tape reproducing apparatus 11 error-corrects the reproduced digital information signal, and when an uncorrectable error is detected in the error-corrected digital information signal,
The dubbing is stopped, the magnetic tapes 1 and 17 loaded in the magnetic tape reproducing device 11 and the magnetic tape recording device 18 are both rewound by a predetermined amount, and then the dubbing is restarted. The second aspect of the present invention is a digital information signal dubbing method in which a reproduced digital information signal from the magnetic tape reproducing apparatus 11 is supplied to a magnetic tape recording apparatus 18 for dubbing. When the uncorrected error is detected for the first time in the unit signal section of the error-corrected digital information signal, the reproduced digital information signal is error-corrected, and the dubbing is stopped and the magnetic tape reproducing apparatus 1
1 and the magnetic tapes 1 and 17 loaded respectively in the magnetic tape recording device 18 are both rewound by a predetermined amount, then dubbing is restarted, and after restarting the dubbing, the same unit signal of the error-corrected digital information signal When an error that cannot be corrected in the section is detected again, the error-corrected digital information signal is corrected and then dubbing is restarted.

[0006]

First, a dubbing apparatus according to an embodiment of the present invention will be described with reference to FIG. In FIG. 1, 11 indicates a reproducing side digital VTR, and 18 indicates a recording side digital VTR.
Indicates. First, the reproducing VTR 11 will be described. Two
Is a rotary magnetic head arranged on the tape guide drum at an angular interval of 180 degrees, and is recorded so as to form an inclined track on the magnetic tape 1 guided and run so as to be wound around the tape guide drum at a wrap angle of 180 degrees. Play the digital video signal. The reproduced digital video signal is supplied to the data reproduction circuit 3 and demodulated, and then supplied to the time base collector 4 to correct the time axis error, and the digital video signal with the time axis error corrected is output. , And is supplied to the error correction circuit 5 for error correction. This error-corrected reproduced digital video signal is supplied to the high-efficiency coding decoder 7 and expanded, and then supplied to the error correction circuit 8 so that the error-corrected digital video signal contains uncorrectable errors. When detected, the error is corrected based on an error flag described later. In the error correction circuit 5, even if the reproduced digital video signal is error-corrected, if there is an error that cannot be corrected, an error flag is generated and supplied to the decoder 7 and the error correction circuit 8 described above. With
It is supplied to the system control microcomputer 6. The microcomputer 6 supplies a control signal to the drive system of the recording side digital VTR 18, and also supplies a control signal to the self drive system (drive system of the reproducing side digital VTR 11) to run the magnetic tapes 17 and 1 respectively. To control. Also, 9
Is a changeover switch for switching the output of the decoder 7 and the output of the error correction circuit 9, and 10 is the changeover switch 9
Is an output terminal derived from.

Next, the recording side digital VTR 18 will be described. The reproduction digital video signal from the output terminal 10 of the reproduction side digital VTR 11 is supplied from the input terminal 12 to the high efficiency encoding encoder 13 and compressed, and then supplied to the parity generation circuit 14 to which parity is added and error correction is performed. After being encoded, supplied to the recording modulation circuit 15, and modulated, the magnetic tape is guided and run so as to be wound at a wrapping angle of 180 degrees. A pair of rotating magnetic tapes mounted at an angular interval of 180 degrees on a tape guide drum. It is supplied to the head 16, recorded on the magnetic tape 17 so as to form an inclined track, and dubbed.

Next, referring to the flowchart of FIG.
The function of the system control microcomputer 6 of the reproducing side digital VTR 11 will be described. In step ST-1,
After the recording side digital VTR 18 is set in the recording standby state, the process proceeds to step ST-2. In step ST-2, the digital VTR 11 on the reproducing side is put into the reproduction standby state, and then the process proceeds to step ST-3. At step ST-3, the recording and reproducing side digital VT of the recording side digital side VTR 18 is recorded.
The reproduction of R11 is started to start dubbing, and then the process proceeds to step ST-4. At this time, the error-corrected reproduced digital video signal from the high-efficiency encoding decoder 7 of the reproducing-side digital VTR 11 is supplied to the recording-side digital VTR 18 through the changeover switch 9. In step ST-4, it is determined whether or not the reproduced digital video signal from the error correction circuit 5 has an error that cannot be corrected and has an error amount larger than a predetermined value α. If YES, the process proceeds to step ST-5. If it is NO, the process proceeds to step ST-7.

In step ST-5, it is judged whether or not the current errored frame number of the reproduced digital video signal and the previous errored frame number do not match, and Y
If ES, the process proceeds to step ST-6, and if NO, the process proceeds to step ST-11. At step ST-6, the recording side digital VTR 18 and the reproducing side digital VT
Stop running the magnetic tapes 17 and 1 in R,
After stopping the dubbing, the process proceeds to step ST-8.
In step ST-8, a control signal from the microcomputer 6 to a drive system (not shown) of the recording side digital VTR 18 rewinds the magnetic tape 17 of the recording side digital VTR 18 by a predetermined amount, and then proceeds to step ST-9. Transition. At step ST-9, the microcomputer 6
After rewinding the magnetic tape 1 by a predetermined amount (equal to the rewinding amount of the magnetic tape 17 of the recording side digital VTR 18) by the control signal from the reproducing side digital VTR 11, that is, its own drive system (not shown). , Step ST-10
Move to. In step ST-10, the frame number of the frame in which the error of the reproduced digital video signal in which the error is corrected by the error correction circuit 5 is generated is stored in the memory of the microcomputer 6, and then in step ST-10.
Return to 1. At step ST-7, the playback side digital VT
It is judged whether or not the stop button of R11 is pressed, and YES
If so, the recording side digital VTR 18 and the reproducing side digital VTR
In addition to stopping the running of the magnetic tapes 17 and 1 of TR11, the recording and reproducing operations are stopped to end the dubbing. If NO, the process returns to step ST-4. In step ST-11, the reproduced digital video signal from the error correction circuit 8 is supplied to the recording side digital VTR 18 through the changeover switch 9 for dubbing, and then the process proceeds to step ST-7.

In the above embodiments, the case where the digital image signal is the digital video signal has been described, but other digital information signals such as a digital audio signal may be used.

[0011]

According to the digital information signal dubbing method of the present invention described above, the reproduced digital information signal from the magnetic tape reproducing apparatus is supplied to the magnetic tape recording apparatus to perform the dubbing of the digital information signal. In the system, it is possible to avoid dubbing of a digital information signal having deteriorated signal quality as much as possible.

[Brief description of drawings]

FIG. 1 is a block diagram showing a dubbing apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the function of a system control microcomputer during dubbing of a playback side digital VTR.

[Explanation of symbols]

1 magnetic tape 2 rotating magnetic head 3 Data reproduction circuit 4 Time base collector 5 Error correction circuit 6 System control microcomputer 7 High efficiency decoder 8 Error correction circuit 9 Changeover switch 10 output terminals 12 input terminals 13 High efficiency coding encoder 14 Parity generator 15 Recording modulation circuit 16 rotating magnetic head 17 magnetic tape

Claims (2)

[Claims] 1. A dubbing method of a digital information signal in which a reproduced digital information signal from a magnetic tape reproducing device is supplied to a magnetic tape recording device to perform dubbing. In the magnetic tape reproducing device, the reproduced digital information is recorded. The signal is error-corrected, and when an uncorrectable error is detected in the error-corrected digital information signal, dubbing is stopped and the magnetic tape reproducing device and the magnetic tape recording device are respectively loaded. A dubbing method for digital information signals, characterized in that the magnetic tape is rewound by a predetermined amount together and then the dubbing is restarted. 2. A dubbing method of a digital information signal, wherein a reproduced digital information signal from a magnetic tape reproducing device is supplied to a magnetic tape recording device to perform dubbing. In the magnetic tape reproducing device, the reproduced digital information signal is recorded. The signal is error-corrected, and when an uncorrectable error is detected for the first time in the unit signal section of the error-corrected digital information signal, the dubbing is stopped and the magnetic tape reproducing apparatus and the magnetic tape recording apparatus are stopped. Rewind the loaded magnetic tapes by a predetermined amount together, then restart the dubbing, and after restarting the dubbing, the error that could not be corrected in the same unit signal section of the error-corrected digital information signal is again detected. If detected, the error is corrected in the error-corrected digital information signal, and Dubbing method for digital information signals, which is characterized by restarting the ringing.