JP3587649B2 - Magnetic recording / reproducing method and apparatus therefor - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a magnetic recording / reproducing method and apparatus capable of reducing the time required for a time code search.
[0002]
[Prior art]
In a magnetic recording / reproducing apparatus capable of intermittent recording / reproducing, there are tapes recorded with various intermittent recording times according to the intermittent recording time set at the time of recording. As a means for playing back those tapes and searching for a scene to be viewed, it is necessary to search for the time code value while playing back or fast-forwarding / rewinding it, which takes a considerable amount of time.
[0003]
FIG. 5 is a block diagram of a conventional magnetic recording / reproducing apparatus.
1 is a system control unit for controlling the operation of the magnetic recording / reproducing apparatus. 2 is a unit for comparing the time code search position data C input from the outside with the current time code data B, and sending a control signal A for the search operation. A target position search controller 3 serving to send the data to the system controller 1 is a time code controller serving to read a time code value and transmit the read time code value to the target position search controller 2.
[0004]
A is a control signal for controlling the operation of the magnetic recording / reproducing apparatus, time code data B is time code data including month, day, hour, minute, and second, and time code search position data C is month, day, hour, minute, and second. Is search position data of a time code including the time code.
[0005]
The operation of the conventional magnetic recording / reproducing apparatus configured as described above will be described below. When the time code search position data C is externally input, the target position search control unit 2 compares the time code search position data C with the time code data B read by the time code control unit 3 to generate an appropriate control signal A up to the search position. It is transmitted to the system control unit 1. The system control unit 1 searches for a location that matches the time code search position data C on the recording medium by controlling the operation of the magnetic recording / reproducing device according to the control signal A of the target position search control unit 2.
[0006]
[Problems to be solved by the invention]
However, in the conventional magnetic recording / reproducing apparatus configured as described above, the target position cannot be searched unless the time code data of the recording medium is read out, so that there is a problem that a considerable search time is required.
[0007]
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problem, and to reduce the search time by enabling the inspection up to the search position to be performed by replacing the time code search with the CTL search in the time code search. .
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a method of reproducing a video signal recorded on a recording medium from a time code read from a time code control unit when a recording medium on which a time code is recorded and standard recording and intermittent recording are reproduced is reproduced. By calculating the intermittent recording interval, and calculating the time code data read by the time code control unit and the time code search position data input from the outside, the difference between the time code values up to the search position is obtained. Based on the value difference and the intermittent recording interval already obtained, the standard recording time converted to the time code value difference at the time of standard recording is obtained, and the time code up to the search position in the standard recording time calculated by the above method is obtained. By calculating the difference between the values and the CTL counter data of the recording medium currently being reproduced, the CTL counter data is calculated. The control signal for controlling the operation of the magnetic recording / reproducing apparatus up to the search position is calculated by comparing the calculated search position value with the CTL counter data from the system control unit. In this case, the search to the search position can be performed by replacing the time code search with the CTL search, and the search time can be reduced.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
The invention described in claim 1 of the present invention obtains an intermittent recording interval value of a video signal recorded on a recording medium by reproducing a recording medium on which a time code is recorded and standard recording and intermittent recording are performed, By calculating the time code data of the currently playing recording medium and the time code search position data of the search position input from the outside, the difference of the time code value up to the search position is obtained, and this time code value is calculated. The standard recording time value converted into the difference between the time code values at the time of standard recording is obtained from the difference between the standard recording time value and the intermittent recording interval value already obtained, and the standard recording time value calculated by the above method and the currently reproduced By calculating the CTL data of the recording medium, the search position converted into the CTL data and the CTL search value are calculated, and in the time code search, the search position is calculated. By performing by replacing the search from the time code search CTL search is a magnetic recording and reproducing method is characterized in that it possible to shorten the search time.
[0010]
According to the invention described in claim 2 of the present invention, the intermittent recording interval value of the video signal recorded on the recording medium is reproduced by reproducing the recording medium on which the time code is recorded and the standard recording and the intermittent recording are performed. The difference between the time code value up to the search position is calculated by calculating the time code data of the recording medium currently being reproduced and the time code search position data of the search position input from the outside. A standard recording time calculation unit that calculates a standard recording time value converted to a time code value difference when standard recording is performed, based on the obtained time code value difference and the already obtained intermittent recording interval value; By calculating the standard recording time value and the CTL data of the recording medium currently being reproduced, a search position converted into CTL data and a CTL search value are calculated. A magnetic recording / reproducing apparatus comprising a target position calculating unit, wherein a search up to a search position is performed by replacing a time code search with a CTL search in a time code search, thereby shortening a search time. Device.
[0011]
An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram of a magnetic recording / reproducing apparatus according to an embodiment of the present invention, and FIGS. 2 to 4 are flow charts of respective parts.
[0012]
The system control unit 1 controls the operation of the magnetic recording / reproducing apparatus according to a control signal A from the target position search control unit 2 and transmits CTL data D to the target position search control unit 2 and the target position calculation unit 4.
[0013]
The target position search control unit 2 compares the control signal A for the search operation with the CTL data D input from the system control unit 1 and the CTL search value G input from the target position calculation unit 4 in FIG. Is a control unit for determining by executing the processing of (1) and transmitting the determined result to the system control unit 1.
[0014]
The time code control unit 3 reads out the time code data B recorded on the recording medium, and transmits it to the target position inspection control unit 2, the standard recording time calculation unit 5, and the intermittent recording time calculation unit 6.
[0015]
The target position calculation unit 4 calculates a CTL search value G (FIG. 3) obtained by calculating a standard recording time value F input from the standard recording time calculation unit 5 and CTL data D input from the system control unit 1. F value) of the target position search control unit 2.
[0016]
The standard recording time calculation unit 5 calculates the difference between the time code value from the current position of the recording medium to the search position based on the time code data B recorded on the recording medium and the time code search position data C input from outside. (The c value in FIG. 3) and the standard time recording value F (in FIG. 3) which can be obtained by calculating the intermittent recording interval value E (the value a in FIG. 2) input from the intermittent recording time calculation unit 6. d value) to the target position calculation unit 4.
[0017]
The intermittent recording time calculator 6 reads out the time code data B recorded on the recording medium by the method of FIG. 2 to obtain an intermittent recording interval value E (a value in FIG. 2). It has the function of transmitting to.
[0018]
The control signal A is a control signal for controlling the operation of the magnetic recording / reproducing apparatus, the time code data B is time code data including month, day, hour, minute, and second, and the time code search position data C is month, day, and time. CTL data D is data recorded on a control track of a recording medium using a vertical synchronization signal every 1/60 second at the time of recording.
[0019]
The intermittent recording interval value E is a time code value that advances by one frame (2 fields = 1 frame) during reproduction. In the case of the NTSC system, it becomes 1 when the recording time is 2 hours (6 hours), and becomes 48 hours. In this case, it is about 24 (recording interval = 0.8 seconds).
[0020]
The standard recording time value F is obtained by calculating the difference between the time code values obtained from the time code data B and the time code search position data C with the intermittent recording interval value E, and is recorded in a state where intermittent recording is not performed. The difference between B and C at the time. The CTL search value G is a value obtained by calculating the standard recording time value F and the CTL data D and replacing the time code search position data C with the CTL data D.
[0021]
【The invention's effect】
As described above, according to the present invention, since the search can be performed by fast-forward / rewind instead of performing fast-forward / rewind while reproducing the recording medium, the search from the vicinity of the beginning to the vicinity of the end of the 120-minute tape is performed. In this case, an advantageous effect is obtained in that the search position can be found in about 2 to 4 minutes instead of about 18 minutes in the past.
[Brief description of the drawings]
FIG. 1 is a block diagram of a magnetic recording / reproducing apparatus according to an embodiment of the present invention; FIG. 2 is a partial flow chart in a magnetic recording / reproducing method according to an embodiment of the present invention; FIG. FIG. 4 is still another partial flowchart of the magnetic recording / reproducing method according to the embodiment of the present invention. FIG. 5 is a block diagram of a conventional magnetic recording / reproducing apparatus.
Reference Signs List 1 system control unit 2 target position search control unit 3 time code control unit 4 target position calculation unit 5 standard recording time calculation unit 6 intermittent recording time calculation unit A control signal B time code data C time code search position data D CTL counter data E Intermittent recording interval value F Standard recording time value G CTL search value a value Intermittent recording interval value d value Standard recording time value f value CTL search value

Claims (2)

By reproducing the recording medium on which the time code is recorded and the standard recording and the intermittent recording are performed, an intermittent recording interval value of the video signal recorded on the recording medium is obtained,
By calculating the time code data of the currently playing recording medium and the time code search position data of the search position input from the outside, the difference of the time code value up to the search position is obtained, and this time code value is calculated. The standard recording time value converted to the difference of the time code value at the time of standard recording is obtained by the difference between the above and the previously obtained intermittent recording interval value,
By calculating the standard recording time value calculated by the above method and the CTL data of the currently reproduced recording medium, the search position converted into the CTL data and the CTL search value are calculated.
A magnetic recording / reproducing method, wherein a time code search is performed by replacing a search up to a search position from a time code search to a CTL search. An intermittent recording time calculation unit that obtains an intermittent recording interval value of a video signal recorded on the recording medium by reproducing the recording medium on which the standard recording and the intermittent recording on which the time code is recorded are performed;
By calculating the time code data of the currently playing recording medium and the time code search position data of the search position input from the outside, the difference of the time code value up to the search position is obtained, and this time code value is calculated. A standard recording time calculation unit that calculates a standard recording time value converted to a difference between the time code values at the time of standard recording by the difference between the above and the intermittent recording interval value already determined,
A search position converted into CTL data by calculating the calculated standard recording time value and CTL data of the currently reproduced recording medium, and a target position calculation unit for calculating a CTL search value;
A magnetic recording / reproducing apparatus characterized in that a search up to a search position is performed by replacing a time code search with a CTL search in a time code search.

Images