KR0170295B1 - Method for generating an area flag of dvcr - Google Patents

Abstract

The present invention relates to an area flag generation method of a digital video tape recorder (hereinafter referred to as DVCR), and more particularly, to generate an area flag for preamble, audio, video, and sub code during reproduction of a standard digital video tape recorder. It is about a method.

Accordingly, an object of the present invention is to provide an area flag for preamble, audio, video, and sub code, including sync block detection, sync block number count step, and block number decoding step within a sync block when playing a standard digital video tape recorder. By providing a method to provide an accurate signal reading during DVCR playback.

Description

How to set up the area of a digital video tape recorder

Fig. 1A shows the tape recording format of the SD-VCR.

FIG. 1B shows the ITI sector in FIG. 1A in detail.

FIG. 1c shows the data of the SSA region of FIG. 1b in detail.

2 is a block diagram showing a reproduction signal processing procedure of the SD-VCR.

3A, 3B, 3C, 3D, 3E, and 3F are waveform diagrams showing conventional flag signal generation for each region of FIG. 1A.

4A and 4B are waveform diagrams near the head switch of FIG. 3B.

5 is a first embodiment of the apparatus to which the area setting method of the digital video tape recorder according to the present invention is applied.

6 is a second embodiment to which the area method of the digital video tape recorder according to the present invention is applied.

Figure 7a shows an ITI sector data area in one track according to the present invention.

FIG. 7B is a waveform diagram showing data of the ITI sector in FIG. 7A.

FIG. 7C is a waveform diagram showing flags for the sync block of FIG. 7B.

FIG. 7D shows the areas of ITI, audio / video and subs carried on the track of the present invention.

7E is a waveform diagram showing pulse waves of the head switch of the present invention.

FIG. 7F is a waveform diagram for detecting the ITI region of FIG. 7d for t1 'time.

FIG. 7G is a waveform diagram for detecting the audio / video region of FIG. 7D for t2 time.

7h is a waveform diagram for detecting the sub code region of FIG. 7d for t3 time.

8 is a first embodiment showing a method for setting a region of a video tape recorder according to the present invention.

9 is a second embodiment showing the area setting method of the video tape recorder according to the present invention.

The present invention relates to a method for setting an area of a digital video tape recorder (hereinafter referred to as DVCR), and in particular, a method for generating area flags for ITI, audio, video, and sub codes during reproduction of a standard digital video tape recorder. It is about.

In the field of video, the digital processing of signals has been rapidly developed and almost practically used, and the signal processing of digital video recorders is also at the stage of commercialization of full digitalized DVCR. Among them, the manufacturers of digital video recorders from each country agreed to announce the specification of the standard digital video tape recorder (hereinafter referred to as SD-VCR).

Figure 1a shows the tape recording format of the SD-VCR, which has an area for ITI PRE-AMBLE at the very beginning of the tape and then continues with the ITI area, GAP1, audio. Areas, gaps (GAP) 2, video areas, gaps (GAP) 3, sub-code areas, and over-write margins (OVER-WRITE MARGIN) are recorded. Here, data such as track information and position information of data for editing are recorded in the ITI area, video and audio data are recorded in the audio and video areas, and auxiliary data such as recording date and time is recorded in the sub code area. have.

The gap portion is an area that distinguishes each sector, and actually records the best signal to recover the clock during reproduction. In the SD-VCR specification, this form is called run-up. There are many reasons for distinguishing each sector as described above. However, the most important thing is that the characteristics of signals recorded for each sector are different.

FIG. 1B shows the details of the ITI sector 4 in FIG. 1A, and FIG. 1C shows the data structure of the ITI sector in FIG. 1B. Here, there are 61 sync blocks (1 sync block = 3 symbols = 30 bits, 1 symbol = 10 bits) in the SSA region 22, 3 sync blocks in the TIA region 23, and each ITI preamble 20 and There is no sync signal in the ITI post-amble 24.

FIG. 1C shows the data of the SSA area of FIG. 1B in detail, and consists of data in which the number of sync blocks of SYNC, ID-U, and ID-L is recorded.

2 is a block diagram and waveform diagram showing a reproduction signal processing procedure of the SD-VCR. For example, the sync signal (SYHC) that enters each sector is different, and the ITI sector is recorded without 24/25 modulation because the 24/25 demodulation is processed separately for each sector during reproduction, and the other sectors perform 24/25 modulation. Go through and are recorded. In addition, the synchronization signal interval of the ITI sector is 3 symbols, the audio / video synchronization signal interval is 90 symbols, and the synchronization signal interval of the sub-code is 25 symbols.

Therefore, the signal processing for one track is processed by dividing each sector and then recombining the data due to the difference between the synchronization signal entering each sector, the presence or absence of digital modulation, and the difference between the synchronization signal and the synchronization signal. That is, when data is detected by the data detector 22 with the signal of the reproduction amplifier 20 as in the signal processing diagram of the SD-VCR of FIG. 2, the ITI area 24, the audio / video area 26, and the sub code area 28 The data is divided by the < RTI ID = 0.0 >

In addition, reproduction signal processing must be performed for each sector. Thus, a signal representing each sector or area is needed for one track. As shown in FIG. 3A, each sector in the track is called an ITI flag 30, an audio / video flag 32, and a sub code flag 34. As shown in FIG. Here, a head switching pulse signal is generated from the drum of the VCR every time one track is changed, as shown in the head switch waveform shown in FIG. 3B. Conventionally, each area flag is generated using this head switch. FIG. 3C is an ITI flag signal waveform diagram, FIG. 3D is an audio / video flag signal waveform diagram, FIG. 3E is a sub code flag signal waveform diagram, and FIG. 3F is an elapsed time t for each sector.

Therefore, the ITI sector is changed for 11 hours after the head switch is changed, the ITI sector is changed, the audio / video area after t2 time, and the sub-code area for t3.

However, the reproduction method as described above has the following problems.

In other words, DVCR has a block that allows the first part of a signal to be aligned with the leading edge of a track during recording. The precision of this block is strictly required. However, even if the block is precise, the DVCR controls the drums during servo playback so that the head always comes to the beginning of the track, but in SD-VCR, the head drum rotates to 9000 R.P.M.

In fact, the SD-VCR specification only specifies 174 ° of the head switch 180 °, so that signal placement can be arbitrarily performed for the remaining 6 °. That is, there may be a maker that records at 174 ° from the beginning at the time of recording, or a maker who records in half and half. The situation in this case is shown in FIG. 4, and the head switch change part and the envelope actually come out irregularly as shown in FIG. 4B during reproduction.

In such a case, an area may be recognized that does not fit each sector during DVCR playback. For example, the audio / video sector may end when the audio / video sector is in progress and vice versa.

Accordingly, an object of the present invention is to set an area for the preamble, audio, video, and sub code by using the number of sync blocks and the block number in the sync block when playing a standard digital video tape recorder. Is to provide a way to do that.

A first embodiment of the present invention for achieving the above object is an ITI area with a predetermined number of sync blocks, an audio / video area with audio and video data, and a sub code with auxiliary data when playing a standard video tape recorder. In a method for generating a flag of an area,

A sync block count count step of detecting a sync block of the ITI region and counting the detected number;

An ITI region recognition step of recognizing, as the ITI region, a time corresponding to a predetermined number of symbols after reaching a predetermined number of counter values in the sync block count step;

An audio / video area recognition step of recognizing, as the audio / video area, a time corresponding to a predetermined number of symbols after an ITI area time has passed in the ITI area recognition step;

And recognizing, as the sub code region, a time corresponding to a predetermined number of symbols after the audio / video region time passes in the audio / video region recognition step.

According to a second embodiment of the present invention for achieving the above object, there is a predetermined number of sync blocks in reproduction of a standard video tape recorder, and ID-U and ID- are recorded after a sync block with a predetermined block number. A method of generating a flag of an ITI region with L data, an audio / video region with audio and video data, and a subcode region with auxiliary data, the method comprising:

A sync count count step of detecting a sync block signal in the ITI region and counting the detected sync blocks;

A sync block number decoding step of decoding a sync block number in the sync block after reaching a predetermined number of counter values in the sync block count step;

An ITI region recognition step of setting a time corresponding to a predetermined number of symbols as the ITI region after the sync block number reaches a predetermined number in the sync block number decoding step;

An audio / video region recognition step of setting, during the ITI region recognition step, a time corresponding to a predetermined number of symbols after an ITI region time has passed as an audio / video region;

And recognizing, as the sub code region, a time corresponding to a predetermined number of symbols after the audio / video region time passes in the audio / video region recognition step.

Therefore, specific embodiments of the present invention will be described in detail with reference to FIGS.

5 is a first embodiment of an apparatus to which the area setting method of a digital video tape recorder according to the present invention is applied, and serial (serial) data (5-DATA) recorded on a tape is transferred to a serial clock (5-CLK). The S / P unit 60 for converting the data into parallel data, the sync detection unit 62 for detecting sync blocks, the sync count unit 64 for counting the number of sync blocks output from the sync detection unit, and the sync count unit. It consists of the flag generation part 66 which generate | occur | produces.

FIG. 6 is a second embodiment of the apparatus to which the area setting method of the digital video tape recorder according to the present invention is applied, and the serial data (5-DATA) recorded on the tape is parallel data according to the serial clock (5-CLK). S / P unit 70 for converting to a synchronous block, synchronous detection unit 72 for detecting a synchronous block, synchronous block number detection unit 74 for detecting a synchronous block number of the synchronous block output from the synchronous detection unit, and the synchronous block number detection unit It consists of a flag generation part 76 which arises as a result of 74. FIG.

FIG. 7 is a waveform diagram showing flag signal generation for each region of FIGS. 5 and 6.

FIG. 7A shows the ITI sector data area 70 in one track.

FIG. 7B is a waveform diagram showing data of the ITI sector in FIG. 7A, and consists of SYN0, ID-U, ID-L ..... SYN62, ID-U, ID-L.

FIG. 7C is a waveform diagram showing a flag for the sync block in FIG. 7B, and a high portion is a flag of the sync block.

FIG. 7d shows the area of the ITI 75, audio / video 76 and sub (SUB) 77 carried on the track.

FIG. 7E is a waveform diagram showing pulse waves of the head switch for reading the track of FIG. 7D.

FIG. 7F is a waveform diagram for detecting the ITI region of FIG. 7d for t1 'time.

FIG. 7G is a waveform diagram for detecting the audio / video region of FIG. 7D for t2 time.

7h is a waveform diagram for detecting the sub code region of FIG. 7d for t3 hours.

As shown in FIG. 7A, the first valid data coming from a track is an ITI sector 70 to use a synchronization signal included in the ITI sector 50. FIG. That is, as shown in FIG. 7B, there are 63 sync blocks SYN0 to SYN63 in the ITI sector in FIG. 7A, followed by ID-U and ID-L data in which sync block numbers are recorded.

Therefore, the Nth sync signal is generated by using the SYNCO, SYNCI ..................... detection and recovery method in the ITI sector as shown in FIG. 7C using the SYNC, ID-U, and ID-L structures. Detected, and thus the audio / video region 76, sub code region 77 in FIG. 7d.

Also, as shown in FIG. 7f at intervals of one track according to the high and low signals of the head switch pulse waveform shown in FIG. 7e, if the sync signal in the ITI sector is found N times, this is referred to as the sync recorded in the ITI sector. Based on this, it is recognized as an ITI sector during t1 '.

Next, as shown in Figs. 7g and 7h, it is determined as the audio / video area (Fig. 7g) during t2 after t1 'and as a sub code area (Fig. 7h) during t3. The times t1 ', t2, and t3 can be determined by looking at the number of symbols in the standard-recording data format of the digital video tape recorder, so that the time can be determined.

Another second embodiment is a method of determining by looking at the contents of ID-U and ID-L data displayed in one sync block. That is, since the sync block number is recorded in ID-U and ID-L, it is detected. Each area is determined as described above.

The flow chart shown in Figs. 8 and 9 in combination with the apparatus of Figs. 5 and 6 will be described in detail the area setting method of the digital video tape recorder according to the present invention.

8 is a first embodiment of a method for setting a region of a video tape recorder according to the present invention. The number of synchronization counts (steps 80, 81, 82, 83, 84), the ITI area setting step (85), and audio / video The data area setting step (step 86) and the sub code area setting step (step 87,88) are performed.

First, in the initial state, the count is initialized to 0 (step 80). When playback is toggled by the head switch (not shown) as shown in FIG. 7E (step 81), data on the track is read out and converted into parallel data in the S / P unit 60. FIG. The first valid data from one track is data of the ITI area, and thus the synchronization block included in the ITI sector is used. In the read data, a sync block signal of the ITI region is detected by the sync detector 62 (step 82). The detected sync block signal is counted at regular intervals by the sync count unit 64 to increase the count value (83 steps), and if the counted value is N times (63 times in the SD-VCR standard) (84 steps) It is determined that this is a sync block recorded in the ITI area, and the flag generator 66 generates the t1 'flag and sets it as the ITI area for the time t1' (step 85). A t2 flag is generated (step 86) after the t1 'time for a time corresponding to the predetermined number of symbols and set to the audio / video data area.

In addition, a t3 flag is generated (step 87) for a time period t3 from t2 to a predetermined number of symbols, and is set as a sub code area. The number of symbols for the times t1 ', t2, and t3 is known in the standard of digital video tape recorders. During this process, the DVCR is played back. If the DVCR does not stop and continues to play, return to the initialization step. Complete the playback (88).

9 is a second embodiment of the method for setting a region of a video tape recorder according to the present invention. The number of sync counts (90, 91, 92, 93, 94), the sync block number decoding (95) and the ITI region A setting step (step 96), an audio / video area setting step (step 97), and a sub code area setting step (steps 98, 99) are performed.

First, in the initialization state, the count is initialized to 0 (step 90). When toggled by the head switch (not shown) as shown in FIG. 7E at the start of playback (step 91), data on the track is read out and the S / P unit ( Is converted into parallel data. In the read data, the sync block signal of the ITI region is detected by the sync detector 62 (step 92). The detected sync block signal is counted at regular intervals by the sync count unit 64 to increase the count value (step 93). If the counted value is the Nth (63 times in the SD-VCR standard) (step 94), It is determined that the sync block is recorded in the ITI area.

At this time, when the count becomes N, the sync block number included in the ID-U and ID-L data in the sync block signal is decoded to determine whether the sync block number in the ID-U and ID-L data is K (e.g. 63). Based on this, the flag generator 66 generates the t1 'flag and sets the ITI region for the time t1' (step 96). A t2 flag is generated (step 87) after t1 'for a time corresponding to a predetermined number of symbols and is set as an audio / video data area.

The t3 flag is generated during the t3 time period from t2 time to the predetermined number of symbols (step 98), and is set as a sub code area. While processing this process, the DVCR is played back. At this time, if the DVCR is not stopped and continues to play, the DVCR returns to the initialization step and if it stops, playback is completed (step 99).

As described above, according to the present invention, accurate signal reading of an area for ITI, audio / video data, and sub code can be performed during reproduction of a standard video tape recorder.

Claims (2)

A method of setting each area during playback of a digital video tape recorder having a track information area comprising a predetermined number of sync blocks, a data area consisting of a predetermined number of symbols, and a sub code area consisting of a predetermined number of symbols, wherein the tracks are set. Detecting a sync block of the information area and counting the number of blocks; Setting the time period to the track information area when the count value becomes a predetermined number, and setting the time period corresponding to the predetermined number of symbols to the sub code area after the time of the track information area. An area setting method of a digital video tape recorder characterized by the above-mentioned. A method of setting each area during playback of a digital video tape recorder having a track information area comprising a predetermined number of sync blocks, a data area consisting of a predetermined number of symbols, and a sub code area consisting of a predetermined number of symbols, wherein the tracks are set. Detecting the sync block in the information area and counting the number of blocks; Decoding the sync block number in the sync block when the counter value is a predetermined number in the step; In this step, when the sync block number reaches a predetermined number, the time period is set as the track information area, the time area corresponding to a predetermined number of symbols after the time of the track information area is set as the data area, and And setting a time period corresponding to a predetermined number of symbols after the time as a sub code area.