KR950003626B1 - Interleaving system of digital vcr - Google Patents

Abstract

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Description

Digital VRL Interleaving Device

1 is a block diagram of an interleaving apparatus of a conventional digital BC.

2 is an explanatory diagram of operations during interleaving in FIG.

3 is an explanatory diagram of a head trace according to the head speed.

Figure 3a is an explanatory diagram showing the head trace path during the high-speed search,

3B is a track trace explanatory diagram of the head during the high speed search.

4 is a circuit diagram of an interleaving apparatus of the present invention Digital VR.

5 is an explanatory diagram at the time of interleaving in FIG.

* Explanation of symbols for main parts of the drawings

1: source coder 2: memory mapper

3: Interleaving control 4: Inter leaver between segments

5: Outer encdder 6: Intersegment interleaver

7: Inner Encoder

The present invention is to correct an error in data output by adjusting the interleaving range according to the degree of error occurring during recording or transmission of compressed data in a digital VRL. In particular, in the case of shift reproduction, a burst error is eliminated. The present invention relates to an interleaving device of a digital VRL to improve the ability to correct a cluster error by limiting it to a random error.

Conventional digital interleaving device configuration of digital BC is as shown in Figure 1, the first sector array memory (sector) to externally encode the input digital data stream to the external code check symbol added data The external coder 11 sequentially outputs the data to the array memort: 12 and the data stored in the first sector array memory 12 in an order different from that of the input order to internally encode the data. Correct the error by decoding only the data appended with the internal code check symbol after playing the data appended with the internal code 13 and the external code and internal code check symbol recorded on the tape T. And an internal decoder 14 for detecting and interleaving the detected error and distributing and storing it in the second sector array memory 15, and the second sector array memory. It consists of an external decoder 16 which reads the data stored in (15) in a different order from the input order, decodes and outputs the externally encoded check symbol data.

Referring to the prior art configured in this way in detail as follows.

When the digital data stream is input to the external encoder 11, as shown in FIG. 2A, the external data is encoded in the longitudinal direction with respect to the input information symbol string to output the data to which the external code check symbol is added. A redundant amount of information is added to the data to which the call check symbol is added, as shown in FIG. 2B, and stored in the first sector array memory 12 in the same order as in the second chart.

Then, the internal encoder 13 performs interleaving which reads from the first sector array memory 12 in a different order from the input order so that the order of data is mixed unlike the input data stream, so the cluster error is irregular. Will be replaced by an error.

The data stream which has undergone such interleaving process enters into the internal caller 13 and is internally coded to perform stronger ECC (Error Correction Coding).

Therefore, when an error occurs, the internal decoder 14 decodes the data recorded on the tape T, corrects the error, and detects the error.

In correcting the error, errors outside the capability of the internal decoder 14 are interleaved and distributed to the second sector error memory 15 through interleaving.

The outer decoder 16 decodes the data recorded in the second sector error memory 15 to correct the remaining errors. This prevents errors of the type of errors that occur during playback on a digital VCD.

These prior arts can focus on the error correction ability, and can boast a strong error correction possibility for various errors that occur when the data recorded in the VRC is reproduced. Until now, digital VRLs such as one-dimensional and two-dimensional tubes are still present. The above method is used, but in reality, there is a problem such as limitation of the recording band and price in home digital VR, and the use of sophisticated devices, and an important problem in trick play such as FF (fast forward). There is this.

In order to solve the above problems, the digital V is limited to interleaving area according to the maximum double speed of the present invention and the interleaving is perfectly performed in the area to facilitate trick play of the recording band and V-CAL. Invented an interleaving apparatus of a seed, and will be described in detail below with reference to the accompanying drawings.

4 is a block diagram of an interleaving apparatus of the present invention Digital VRL, as shown here, a source encoder (1) which performs compression encoding on an input digital data stream, and compression encoding through the source encoder (1). It generates additional information such as classification information and status information necessary for V-Cal to make the data stream into a certain format suitable for V-Cal, and stably reproduces each other at the maximum speed of V-Cal. An interleaving controller 3 for restricting the interleaving area on a segment basis so that the interleaving controller 3 adds additional information of the interleaving controller 3 to the compressed data stream inputted from the source encoder 1, 2) and inter-segmentally in units of segments in the memory mapper 2 restricted by the interleaving controller 3. Inter-segment interleaver (4) for performing ice, an external encoder (5) for performing external encoding on interleaved data streams, and intrasegment interleaver (6) for interleaving in interleaved segment and reconstructed segment. ) And an internal encoder 7 which performs internal encoding on the data stream generated through the intra-segment interleaver 6.

Referring to the operation and effect of the present invention configured as described above in detail.

In the case of digital V-realization, if a fast search function such as fast-forwarding (FF) is realized, the video head passes as shown in FIG. 3a. Thus, data that cannot be read at high speed compared to the area where the head contacts at normal as shown in FIG. 3b. Errors propagate, and even the most powerful ECC (Error Correction Coding) is useless.

Therefore, the maximum range that can be interleaved should be smaller than the area covering the track at the maximum speed provided by VRC, which can be expressed as follows.

… … … … … … … … … … … … … … … … … … … … … … (One)

S: interleaving area (0≤S≤1)

N: Maximum speed during playback

T-D: amount of head over the track (0≤T-D≤1)

First, when the source encoder 1 receives the digital data stream, compresses the encoded data, and outputs the data stream as shown in FIG. 5A, the memory mapper 2 adds additional information of the interleaving controller 3 to the input compressed data stream. In addition, it is completed in a certain data format and stored in segments as shown in FIG. 5B.

At this time, the interleaving controller 3 generates additional information such as classification information and status information necessary for VC to make the data stream compressed and encoded by the source encoder 1 into a predetermined format suitable for VC. In addition, the interleaving area is limited in units of segments so as to be stably reproduced at the maximum speed of V-Cal, and the above equation (1) is explained so that the effect of interleaving does not decrease even during normal and high speed playback.

In other words, the interleaving area S is inversely proportional to the speed N of the BCAL, and the area becomes smaller as the speed increases, and the amount of the VRC head over the track is proportionally limited.

Therefore, if T-D = 1, the head center coincides with the track center and the tracking is perfect. If T-D <1, the track center is out of the head center. As a result, when using a shift mode other than normal playback, the head passes through several tracks, and therefore, the range that the head can read from any track is in the range of 0≤T-D≤1.

Therefore, the intersegment interleaver 4 reads the data uniformly formatted in the memory mapper 2 in units of segments, performs interleaving in units of segments, and sends the data to the external units 5. The interleaved data stream is interleaved through the intersegment interleaver 4 to be sent to the intrasegment interleaver 6, and the intrasegment interleaver 6 is reconstructed in the segment reconstructed by the intersegment interleaver 4. Interleaving is performed to make the data stream random as shown in FIG. 5C.

Then, the data received from the intra-segment interleaver 6 is ECC (Error Correction Coding) in the internal encoder 7, is recorded on the video tape by the head after performing the internal coding.

Therefore, the present invention has the effect of allowing the user to apply it to a home VR by limiting an arbitrary maximum speed and using the limited speed as the minimum interleaving area to enable interleaving only in the area.

Claims (2)

A source coder 1 that performs compression encoding on the input digital data stream, and a classification necessary for VRC to make the data stream compressed and coded by the source coder 1 into a certain format suitable for VRC. An interleaving controller (3) which generates additional information such as information and status information and restricts the interleaving area in units of segments so as to be stably reproduced at a maximum speed of V-Cal. In the memory mapper 2 which adds the additional information of the interleaving controller 3 to the compressed data stream input from (1) and completes it in a predetermined format, and in the memory mapper 2 restricted by the interleaving controller 3. Intersegment interleaver (4) for interleaving on a segment basis, and external to the interleaved data stream Internal encoding is performed on an external encoder 5 for performing encryption, an intrasegment interleaver 6 for interleaving in a segment reinterleaved and reconstructed between segments, and a data stream generated through the intrasegment interleaver 6. An interleaving device of a digital BC, comprising an internal unit 7 to perform. 2. The interleaving area limited by the interleaving controller 3 is characterized in that the area becomes smaller as the speed increases in inverse proportion to the speed of the V-Cal, and is limited in proportion to the amount of the V-Cal head over the track. Digital VRL interleaving device.