JPH09128907A - Frame number correction device and method - Google Patents

Abstract

(57) Abstract: It is possible to surely obtain a recognition of a reproduction position on a frame-by-frame basis, and particularly to make a frame number correction function highly reliable. In an input signal, one sector is composed of a plurality of frames, one frame is composed of a synchronization number and a data area as a synchronization signal, and the numbers when at least three synchronization numbers are consecutive are all within one sector. It is a combination of different numerical values, and consecutive frame numbers of consecutive frames in one sector can be identified by the numerical values. Frame number output unit 104 and correction determination unit 10
Reference numeral 5 compares the predicted frame number from the synchronization signal detection unit 103 with the detected frame number from the frame number detection unit 102, and if they match, outputs the predicted frame number as an output frame number, indicating a mismatch. , And the predicted frame number is corrected and output only when the state of the detected frame number satisfies a predetermined condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention records a sync signal and a frame number required for data management when recording video, audio or various information on a recording medium such as an optical disk and reproducing the recorded information. And a frame number correction device and method effective for reproduction.

[0002]

2. Description of the Related Art In recent years, optical discs have been developed which can record and reproduce information using laser light as a medium. Here, various proposals have been made as a format for recording information on an optical disk, but in any case, a sync signal is indispensable. When reproducing such an optical disk, the synchronization signal is reproduced, the synchronization signal is counted, and the frame is determined by the count value. That is, the frame is detected by counting the synchronization signals. However, if the disc makes an abnormal rotation, the length of the frame becomes longer or shorter. Then, a count error of the sync signal or the like occurs and it becomes unclear which frame in the sector is being reproduced, and all the data reproduced here becomes an error.

[0003]

As described above, the frame is detected by detecting the sync signal. However, when the disk makes an abnormal rotation, the length of the frame becomes longer or shorter. A synchronization signal count error occurs. Then, it may be unclear which frame in the sector is being reproduced. In such a case, all the data reproduced here become an error.

Therefore, the present invention ensures that the reproduction position can be recognized on a frame-by-frame basis, and in particular, has developed a frame number correction function and has made its performance highly reliable. It is intended to provide a method.

[0005]

One sector is composed of a plurality of frames, one frame is composed of a synchronization number as a synchronization signal and a data area, and the synchronization number has at least three consecutive numbers within one sector. Are set so that they all have different numerical values, and the input section to which information is input so that the continuous frame number of each continuous frame within the one sector can be identified by the numerical value and the synchronization Frame number detection means for detecting a number and combining a plurality of synchronization numbers to generate a detection frame number;
Sync signal generating means for generating the sync signal by capturing the sync number as a sync signal; frame number generating means for generating an expected frame number at the timing of the sync signal;
The predicted frame number and the detected frame number are compared, and if they match, the predicted frame number is output as an output frame number, and they do not match, and the state of the detected frame number satisfies a predetermined condition. And the correction means for correcting and outputting the predicted frame number.

The predetermined condition is that the detected frame numbers are consecutive, for example, two frames. If they are not consecutive, no correction is made. The predetermined condition is that the difference between the detected frame number and the expected frame number is within ± 2 frames. If the difference between the detected frame number and the expected frame number is large, no correction is made. With the above means, the output frame number becomes highly reliable.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a diagram showing an embodiment of the present invention, and FIG. 2 is an explanatory diagram of an input signal to the input section of FIG. This input signal is of the type shown in, for example, Japanese Patent Application No. 7-86872. Further, FIG. 3 is a diagram showing a combination of three of the frame number of the input signal and a synchronization number continuous with the synchronization number, and a combination of four.

Here, a signal reproduced from a recording medium (optical disk) is assumed. In this reproduced signal, one sector consists of a plurality of frames (in the example of FIG. 2, one sector has 26 frames).
flame). Then, one frame consists of a synchronization number as a synchronization signal and a data area, and the synchronization numbers are combined and set so that at least three consecutive numbers have different numbers within one sector (Fig. 3). That is, as shown in FIG. 3, the synchronization numbers are 0, 5, 1, 5, in ascending order of frame numbers 0, 1, 2, 3, 4 ,.
They are assigned in the order of 2, 5, 3, 5, 4, ... As you can see from the combination of the synchronization numbers, when you see the numbers by combining three or four consecutive synchronization numbers, you can see that the same number does not exist in one sector. Is assigned. Therefore,
The frame number can be recognized by the numerical contents of each frame.

Returning to FIG. 1, description will be made. The signal arranged as described above is input to the input terminal 100. This input signal is input to the synchronization number detector 101. The synchronization number detected by the synchronization number detector 101 is input to the frame number detector 102. The frame number detection unit 102 continuously combines three or four input synchronization numbers to generate the numerical value shown in FIG. 3, determines the frame number from this numerical value, and outputs it as the detected frame number.
If the combination of synchronization numbers is "470", the frame number is "0", and if "705", the frame numbers are "1" and "0".
If it is "51", the frame number is output as "2". This frame number is the detected frame number.

The input signal is also input to the sync signal detecting section 103. The sync signal detection unit 103 detects the input timing of the sync number as the sync signal and outputs the sync signal regardless of the content of the sync number. The synchronization signal is supplied to the frame number output unit 104. The frame number output unit 104 up-controls a counter that is reset at, for example, 26 each time a synchronization signal is input,
The expected frame number is being generated.

The expected frame number is input to the correction determination section 105. The correction determination unit 105 compares the predicted frame number and the detected frame number and determines whether the two match. When the predicted frame number and the detected frame number match, the modification determination unit 105 outputs, for example, "0" as the modification instruction signal. At this time, the frame number output unit 104 outputs the predicted frame number as the output frame number. On the contrary, if they do not match and the characteristic of the detected frame number satisfies the predetermined condition, the correction determination unit 105 outputs "1" as the correction instruction signal. At this time, the frame number output corrects and outputs the expected frame number, that is, the frame number detection unit 10
The detected frame number output from 2 is fetched, this is output as an output frame number, and the next predicted frame number is generated based on this detected frame number.

The conditions for the correction determination unit 105 to give a correction instruction to the frame number output unit 104 include the following conditions. 4A and 4B specifically show configuration examples of the modification determination unit 105.

The correction determination unit 105 of FIG. 4A and its operation will be described. In FIG. 4A, the detection frame number is input to the mismatch determination unit 201 and the continuity detection unit 202. The non-coincidence determination unit 201 compares the detected frame number with the expected frame number and outputs a logic 1 when they do not coincide with each other. The continuity detection unit 202 detects whether or not the detected frame numbers are consecutive, and outputs a logical 1 when the detected frame numbers are, for example, two frames, that is, two consecutive frames. The AND circuit 203 outputs a correction instruction signal when the two inputs are logic 1. Therefore, the AND circuit 203 outputs a logic 1 which is a correction instruction signal when the expected frame number and the detected frame number do not match and the detected frame number continues twice.

This means the following.
Even if a discrepancy between the expected frame number and the detected frame number is detected, the lack of continuity of the detected frame numbers is due to an error in the detected frame numbers or an error due to a scratch, and is temporary. It was there. Next, when the mismatch between the expected frame number and the detected frame number is detected and there is continuity of the detected frame number, it means that the detected frame number is correct. If the detected frame number is correct and the expected frame number is incorrect, it can be said that there is an error or malfunction in the prediction, or the playback location has changed due to special playback or the like.

FIG. 5A is a timing chart showing the operation of the correction determining section 105 shown in FIG. 4A. Sync numbers from the left are 0, 5, 1, 5, 2, 5, 3,
5 and 1 are continued, but 1 is an error and originally 4
(See table in FIG. 3). However, after error 1, it continued with 5, 1, 6, ... and returned to the original course. That is, the detected frame numbers are not continuous. In such a case, the correction instruction signal cannot be obtained. Therefore, the output frame numbers are stable and consecutive.

In the above description, the correction instruction signal is output when the detected frame numbers are consecutive twice, but the present invention is not limited to this, and the correction instruction signal is output when the detected frame numbers are consecutive three or four times. You can do it. For example, when reproducing a disc having many scratches and pride such as an old disc, the number of times of continuous detection may be variable. That is, the change value may be supplied to the continuous detection unit 202.

FIG. 5B shows an operation timing chart assuming that the continuity detecting section 202 is not provided in the correction determining section 105. Continuity detector 2
Without 02, the correction instruction signal is frequently output, and the output frame number changes each time, which causes a malfunction.

The correction determination unit 105 of FIG. 4B and its operation will be described. In FIG. 4B, the detected frame number is input to the mismatch determination unit 211 and the difference detection unit 212. The non-coincidence determination unit 211 compares the detected frame number with the expected frame number and outputs a logic 1 when the two do not coincide. The difference detection unit 212 calculates the difference between the detected frame number and the expected frame number, and outputs a logic 1 when the difference between the two is within 2 (0, 1, 2), for example. The AND circuit 213 outputs a correction instruction signal when both inputs are 1. Therefore, the AND circuit 213 outputs a logic 1 which is a correction instruction signal when the predicted frame number and the detected frame number do not match and the difference between the detected frame number and the predicted frame number is 2 or less.

This means the following.
Even if a discrepancy between the predicted frame number and the detected frame number is detected, if the difference between the detected frame number and the predicted frame number is large, it may be due to an error in the detected frame number or an error due to a scratch. It was a transitory thing. Next, the fact that the mismatch between the predicted frame number and the detected frame number is detected and the difference between the detected frame number and the predicted frame number is small means that the detected frame number is relatively correct.

FIG. 6 shows the correction determination section 105 of FIG. 4 (B).
3 is a flowchart showing the operation of the embodiment. The sync numbers continue from 0, 5, 1, 5, 2, 5, 3, 5, 1, ... From the left side, but 1 is an error and should originally be 4 (see the table in FIG. 3). But after error 1, 5
It continues with 1, 6 ... and returns to the original course. Since the detected frame number when the synchronization number of the next frame after the error 1 is 5 is 3, and the expected frame number is 9, the difference between the two is large. Since such a thing is not possible in the normal reproduction state, the correction instruction signal is not output.

In the above description, the detected frame number and the expected frame number do not match, and the difference between the two is within 2; however, this number is not limited, and within 3
It may be within 4. By selecting this number, an allowable range can be given to the number of frames to be jumped during special reproduction. The larger the number, the more acceptable the frames are to be played apart. That is, the difference detection unit 212 may be configured to be able to input the changed value.

In the above description, the contents of the three-digit numerical value obtained by combining three consecutive synchronization numbers are used, but the present invention is not limited to this. As shown in FIG. 3, even if the contents of four consecutive synchronization numbers are combined, the same 4-digit numerical value does not exist in one sector (26 frames).
Therefore, the same effect can be obtained by using this 4-digit numerical value.

FIG. 7 shows a timing chart for explaining the operation when the correction instruction signal is generated when a 4-digit numerical value is used. Sync numbers from the left are 0, 5,
1, 5, 2, 5, 3, 5, 1, ... Are continued, but 1 is an error and should be 4 in the original case (see the table in FIG. 3). However, after error 1, it continued with 5, 1, 6 ... and returned to the original course. The detected frame number when the error 1 occurs is “5351” as a 4-digit numerical value, but such a detected frame number does not exist in the table of FIG. In such a case, the expected frame number 8 is set as the output frame number as it is. In the next frame, the 4-digit numerical value is "3515", and this numerical value does not exist in the table of FIG. Therefore, also at this time, the expected frame number 9 becomes the output frame number as it is.

In the next frame, a 4-digit numerical value "515
1 ”, and this numerical value does not exist in the table of FIG. Therefore, also at this time, the expected frame number 10 becomes the output frame number as it is.

In the next frame, the four-digit numerical value "151
6 ”, which does not exist in the table of FIG. Therefore, at this time, the expected frame number 11 (previous 1
The number next to 3) becomes the output frame number as it is.

In the next frame, the 4-digit numerical value "5"
162 ”, which exists as frame number 12 in the table of FIG. Therefore, at this time, the frame number detector 12 outputs the frame number 12 and compares it with the expected frame number 12. In this case, they match, and the expected frame number 12 becomes the output frame number as it is.

As described above, the output frame number can be stabilized by using a four-digit numerical value that uses the four consecutive numbers of the synchronization number. Further, when the consecutive detection unit and the difference detection unit shown in FIG. 4 are used. Furthermore, the stability of the output frame number can be obtained.

Although the above-described embodiments are configured by hardware, it goes without saying that the method of the present invention can be implemented by software. 8 is shown in FIG.
6 shows a flowchart capable of realizing the functions and operations shown in (A) and FIG. 5 (A). In addition, FIG.
7 shows a flowchart capable of realizing the functions and operations shown in (B) and FIG. The flowchart of FIG. 8 will be described. Sync number is extracted from the input signal and stored,
A multi-digit numerical value as shown in FIG. 3 is created (steps A1 and A2). Then, it is determined whether or not a numerical value with a plurality of digits exists in the table shown in FIG. 3, and if it exists, the corresponding frame number is set as the detected frame number (step A4). If it does not exist, the expected frame number is output as the output frame number (step A).
6). Next, when the detection failure number is obtained, the detected frame number is compared with the predicted frame number to determine whether they match (step A5). If they match, the predicted frame number is output. It is output as a number (step A6). If they do not match in step A5,
It is determined whether or not the detected frame numbers have continuity. If the detected frame numbers do not have continuity, it is determined that an erroneous frame number suddenly occurs, and the process proceeds to step A6, where the predicted frame number is set as the output frame number. Output (step A7). However, if the detected frame numbers are continuous in step A7, the latest detected frame number is replaced with the predicted frame number and the output frame number is output (step A8).

The flowchart of FIG. 9 will be described. This flowchart is different from the flowchart of FIG. 8 in the processing when a mismatch is obtained in step A5. That is, the difference between the detected frame number and the expected frame number is calculated, and it is determined whether or not the difference is within a predetermined range (step A11). If it is within the predetermined range, the latest detected frame number is replaced with the expected frame number and the output frame number is output (step A).
12). However, if it exceeds the predetermined range, it is determined that an erroneous frame number suddenly occurs, and step A6
Then, the expected frame number is output as the output frame number.

[0030]

As described above, according to the present invention,
It is possible to surely obtain the recognition of the reproduction position on a frame-by-frame basis, and particularly to make the frame number correction function highly reliable.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a format of a signal input to the device of FIG.

3 is an explanatory diagram of frame numbers and synchronization numbers of signals input to the device of FIG.

FIG. 4 is a diagram showing a configuration example of a correction determination unit in FIG.

FIG. 5 is a timing chart shown for explaining the operation of the determination unit in FIG.

FIG. 6 is a timing chart shown to explain the operation of the determination unit in FIG.

FIG. 7 is a timing chart shown to explain the operation of still another determination unit.

FIG. 8 is a flowchart for explaining an operation example of the apparatus of the present invention.

FIG. 9 is a flowchart shown to explain another operation example of the device of the present invention.

[Explanation of symbols]

101 ... Synchronous number detecting unit, 102 ... Frame number detecting unit, 103 ... Synchronous signal detecting unit, 104 ... Frame number outputting unit, 105 ... Correction determining unit, 201, 211 ... Mismatch determining unit, 202 ... Continuity detecting unit, 203 213 ... AND circuit, 212 ... Difference detecting section.

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Claims (6)

[Claims] 1. One sector is composed of a plurality of frames, one frame is composed of a synchronization number as a synchronization signal and a data area, and the synchronization number is a single or a plurality of consecutive numerical values which are all different within one sector. And the input unit for inputting an input signal that can identify the continuous frame number of each continuous frame in the one sector by the numerical value, and the synchronization number from the input signal. A frame number detecting means for detecting and combining a plurality of synchronization numbers to generate a detection frame number; a synchronization signal generating means for generating a synchronization signal by capturing the synchronization number of the input signal as a synchronization signal; Frame number generating means for generating an expected frame number at a timing, comparing the expected frame number and the detected frame number, If they match, the predicted frame number is output as an output frame number, and only when they do not match and the state of the detected frame number satisfies a predetermined condition, the predicted frame number is corrected and output. A frame number correcting device. 2. The predicting frame number when the correcting means does not match the predicted frame number and the detected frame number, and the detected frame number has N continuity even in subsequent frames. Is corrected to the latest detected frame number and is output. 3. The correction means, when the predicted frame number and the detected frame number do not match and the difference between the detected frame number and the predicted frame number is N or less, 2. The frame number correction device according to claim 1, wherein the frame number is corrected to the latest detected frame number and output. 4. One sector is composed of a plurality of frames, one frame is composed of a synchronization number as a synchronization signal and a data area, and the synchronization numbers have different numerical values when at least three consecutive numbers are different in one sector. The combination number is set so that the continuous frame number of each continuous frame in the one sector can be identified by the numerical value, and the synchronization number is detected from the input signal. To generate a combination detection frame number by accumulating a plurality of synchronization numbers, generate a synchronization signal by capturing the synchronization number of the input signal as a synchronization signal, and generate an expected frame number at the timing of the synchronization signal, The predicted frame number is compared with the detected frame number, and if they match, the predicted frame number is output as an output frame number. , Comparing the expected frame number and the detection frame number, if they do not match, determine whether the detection frame number and the next detection frame number is continuous, if the determination result is discontinuous Outputs the predicted frame number as an output frame number, and when consecutive, corrects the predicted frame number to the latest detected frame number and outputs the latest detected frame number as the output frame number. A frame number correction method characterized by the above. 5. One sector is composed of a plurality of frames, one frame is composed of a synchronization number and a data area as a synchronization signal, and the synchronization number has a numerical value when at least three consecutive numbers are different within one sector. The combination number is set so that the continuous frame number of each continuous frame in the one sector can be identified by the numerical value, and the synchronization number is detected from the input signal. To generate a combination detection frame number by accumulating a plurality of synchronization numbers, generate a synchronization signal by capturing the synchronization number of the input signal as a synchronization signal, and generate an expected frame number at the timing of the synchronization signal, The predicted frame number is compared with the detected frame number, and if they match, the predicted frame number is output as an output frame number. Detecting a difference between the predicted frame number and the detected frame number, and determining whether the difference is within a predetermined value, if the determination result is outside a predetermined value, the predicted frame number as an output frame number A frame number correction method characterized in that when the output is within a predetermined value, the predicted frame number is corrected to the latest detected frame number, and the latest detected frame number is output as an output frame number. 6. One sector is composed of a plurality of frames, one frame is composed of a synchronization number and a data area as a synchronization signal, and the synchronization numbers have different numerical values when at least three consecutive numbers are different in one sector. And an input unit for inputting an input signal, which is configured so that the consecutive frame numbers of consecutive frames in the one sector can be identified by the numerical value, and the synchronization from the input signal. A frame number detection unit that detects a number and generates a detection frame number by combining a plurality of synchronization numbers, and a synchronization signal generation unit that generates the synchronization signal by capturing the synchronization number of the input signal as a synchronization signal, Frame number generation means for generating an expected frame number at the timing of the synchronization signal; the expected frame number and the detected frame number And a means for outputting the predicted frame number as an output frame number when they match, and comparing the predicted frame number and the detected frame number, and there is a mismatch, and the detected frame number And the predicted frame number is N or less, the frame number correction device further comprises means for correcting the predicted frame number to the latest detected frame number and outputting the corrected frame number.