JPH11144381A - Data recording/reproducing device, recording medium used therein, computer system and data reproducing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discriminate the kind of data and to perform a post processing of recording/reproduction suitable to the kind. SOLUTION: Computer data or image data is outputted from PC 1 to DVD- RAM drive 2, these data are recorded in the same recording medium 3 on the side of DVD-RAM drive 2. In this case, an electronic watermark information for identifying the kind of data is buried in the image data. On the DVD-RAM drive 2 side, the data kind is discriminated according to the presence/absence of this electronic watermark information, and on the basis of the discrimination result, a verifying processing at the time of data writing a retry processing at the time of data reading are controlled. In other words, the verifying and the retry processing are executed only in the case of computer data. As a result, processing time can be reduced by omitting the verifying and the retry processing for the image data in which greater importance is attached to continuity of recording/reproduction than to reliability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The invention relates to a data recording / reproducing device such as a RAM drive, a recording medium used in the device, a computer system, and a data reproducing method.

[0002]

2. Description of the Related Art In general, in a device for performing data recording / reproducing processing, at the time of writing data (at the time of recording), a verifying process is performed to check whether or not data is correctly recorded after writing of data. Further, when data is read (during reproduction), several retries are performed when an error occurs.

[0003]

By the way, for example, DV
In a data recording / reproducing apparatus such as a D-RAM drive, computer data and video data having different data formats may be recorded on the same recording medium (disk).

In this case, the computer data is program data or file data created by various application software.
It is data that may make the entire program unexecutable. Therefore, the above-described verification processing and error retry processing are indispensable for emphasizing reliability.

On the other hand, video data is AV (audiovisual) data composed of image data, audio data, and the like, and it is important that recording and reproduction be performed without interruption. Even in such a case, noise is included in a part of the video, but there is no possibility that the AV data cannot be reproduced. Therefore, the above-described verification processing and retry processing are not necessarily required.

As described above, the necessity of the verify process and the retry process differs depending on the type of data. However, conventionally, regardless of the type of such data, a verify process is performed at the time of writing data, and a retry process is performed at the time of reading data (at the time of error).

For this reason, the method of recording and reproducing computer data has a problem that extra time is required for the verification process when writing a large amount of video data. In addition, if a retry process is performed when reading video data, the reproduced video is temporarily interrupted during the retry period, and there is a problem that, for example, the viewer feels unpleasant.

The present invention has been made in view of the above points, and determines the type of data, and performs recording / writing suitable for the type.
An object of the present invention is to provide a data recording / reproducing apparatus which performs post-processing of reproduction, a recording medium used in the apparatus, a computer system, and a data reproducing method.

[0009]

(1) A data recording / reproducing apparatus of the present invention performs a recording / reproducing process on a recording medium capable of recording at least computer data and video data. In particular, in the present invention, data reading means for reading data from the recording medium, digital watermark detecting means for detecting digital watermark information from the data obtained by the data reading means, and digital watermark information by the digital watermark detecting means. If the digital watermark information is not detected, the digital watermark information is determined, and if the digital watermark information is detected, the digital watermark information is determined to be video data. 1).

An error detecting means for detecting the presence or absence of an error in the read data, and a read control means for executing a retry process for the error detected by the error detecting means, the read control means comprising When the read data is determined to be video data by the means, retry processing for the error detected by the error detection means is not performed (claim 2).

The write control means executes a retry process for an error detected by the error detection means when the read data is determined to be computer data by the determination means. (Claim 3).

According to such a configuration, when performing reproduction processing (data reading processing) of computer data and video data having different data formats, the data type is determined according to the presence / absence of digital watermark information, and the computer data is reproduced. Retry processing at the time of error is executed only in the case. Therefore, it is possible to omit the retry processing of the video data in which the continuity of the reproduction is more important than the reliability, and to shorten the time required for the read processing.

(2) The data recording / reproducing apparatus of the present invention performs a recording / reproducing process on a recording medium on which at least computer data and video data can be recorded. In particular, in the present invention, data acquisition means for acquiring data to be written from outside, digital watermark detection means for detecting digital watermark information from data obtained by the data acquisition means, and When digital watermark information is not detected, the digital watermark information is determined to be computer data, and when the digital watermark information is detected, the digital watermark information is determined to be video data. (Claim 4).

The data writing means for writing the data obtained by the data obtaining means to the recording medium, and the verifying processing is not executed when the determining means determines that the obtained data is video data. And a write control means for controlling the write operation.

Further, the writing control means executes a verifying process after the data writing by the data writing means, when the determination means determines that the obtained data is computer data. Claim 6).

According to such a configuration, when recording processing (data writing processing) of computer data and video data having different data formats is performed, the data type is determined according to the presence / absence of digital watermark information, and the data type of the computer data is determined. The verification process is executed only in the case. Therefore,
It is possible to omit the verification process of video data in which the continuity of recording is more important than the reliability, and to shorten the time required for the writing process.

(3) The data recording / reproducing apparatus of the present invention stores data reading means for reading data from a recording medium and, when an error is detected during reading of data by the data reading means, stores the error position. An error position storage means, and read control means for executing a retry process for an error position stored in the error position storage means after completion of reading of the data (claim 7).

The digital watermark detecting means for detecting digital watermark information from the data read by the data reading means, wherein the read control means does not detect the digital watermark information by the digital watermark detecting means. In this case, a retry process is executed in the event of a failure.

According to such a configuration, when an error is detected during data reading, the error position is stored, and data reading in a specified range is continuously performed. Thus, the presence or absence of digital watermark information can be reliably detected. In addition, by executing a retry process for an error position according to the type of the data after the data is read, it is possible to avoid interruption of the data reading every time an error occurs and to shorten the entire processing time. .

(4) The data recording / reproducing apparatus of the present invention performs recording / reproducing processing of at least two types of data having different data formats. In particular, in the present invention, data acquisition means for acquiring data to be written, data writing means for writing data obtained by the data acquisition means to a recording medium, and data writing after the data writing by the data writing means. Write control means for executing a verify process according to the type, data read means for reading data from the recording medium, and retry processing at the time of error according to the type of the data after the data is read by the data read means Writing control means (claim 9).

The writing control means determines whether the data is computer data or video data in accordance with the presence or absence of digital watermark information, and executes a verifying process if the data is computer data (claim 10).

The reading control means determines whether the data is computer data or video data in accordance with the presence or absence of digital watermark information, and executes retry processing when an error occurs if the data is computer data. Item 1
1).

According to such a configuration, when performing recording / reproducing processing of at least two types of data having different data formats, the type of the data is determined according to the presence or absence of digital watermark information at the time of writing the data. The verification process is executed only when is the computer data. Therefore, it is possible to omit the verification process of the video data in which the continuity of the recording is more important than the reliability, and to shorten the time required for the writing process.

When reading data, the type of data is determined according to the presence or absence of digital watermark information, and a retry process for an error is executed only when the data is computer data. Therefore, we omit the retry processing of video data that emphasizes continuity of reproduction over reliability,
The time required for the reading process can be reduced.

(5) The recording medium of the present invention is a medium on which computer data and video data are recorded, wherein the video data has digital watermark information for identifying a data type embedded therein. (Claim 1
2).

According to such a configuration, when reading data from the recording medium, the data type can be determined according to the presence or absence of the digital watermark information, so that processing suitable for the data type can be performed. .

(6) The computer system of the present invention comprises:
The computer comprises a computer and a data recording / reproducing device. The computer outputs computer data or video data, and outputs the video data by embedding digital watermark information for identifying the data type. Computer data or video data to be output is input, and the type of data is determined according to the presence or absence of the digital watermark information. Based on the determination result, a verify process at the time of writing data and a retry process at the time of reading data are performed. It is controlled (claim 13).

According to such a configuration, computer data or video data is output from the computer to the data recording / reproducing device. At that time, digital watermark information is embedded in the video data and output. Therefore,
On the data recording / reproducing apparatus side, the data type can be determined according to the presence or absence of the digital watermark information, and based on the determination result, the verifying process at the time of writing data and the retry process at the time of reading data can be controlled. .

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a computer system using the data recording / reproducing apparatus of the present invention. The system includes a personal computer (hereinafter, referred to as a PC) 1, a DVD-RAM drive 2, and a recording medium 3.

The PC 1 has general computer functions such as file creation using various application software. The PC 1 functions as a higher-level device of the DVD-RAM drive 2 and outputs a data write / read command, outputs data to be written, and the like.

The DVD-RAM drive 2 (data recording / reproducing device) performs recording / reproducing processing of at least two types of data (digital data) having different data formats. In the present embodiment, it is assumed that recording and reproduction processing of two types of data, that is, computer data and video data sent from the PC 1 is performed.

Here, the computer data is data that should not have an error, such as program data and file data created by various application software. The video data is AV (audio / visual) data including image data and audio data. The video data includes digital watermark information (Water Matrix information) for identifying the data type.
rk) is embedded. The process of embedding the digital watermark information is performed on the PC 1 side.

It should be noted that “digital watermark (digital watermar)
"k)" is a technique for embedding and hiding some information in multimedia data such as images and sounds, and is used for copyright protection of digital works. In the present embodiment, by utilizing this “digital watermarking” technology, digital watermark information (Water Mark) is embedded in video data as identification information for identifying the data type, thereby achieving recording suitable for the type of data. / Characterized by performing post-processing of reproduction.

As shown in FIG. 1, the DVD-RAM drive 2 has an interface circuit (hereinafter referred to as an I / F).
11, a CPU 12, a verify management unit 13, a retry management unit 14, a water mark detection unit 15, a write circuit 16, a read circuit 17, and a memory 18 are provided.

The I / F 11 performs data input / output control with the PC 1. The CPU 12 controls the entire DVD-RAM drive 2, and here controls writing and reading of data according to the data type (computer data / video data).

The verify management section 13 performs a verify process when writing data. The verifying process is a process for checking whether data is recorded correctly. The retry management unit 14 performs a retry process when reading data. The retry process is a process of re-reading when an error is detected. The Water Mark detection unit 15 performs a process of detecting digital watermark information (Water Mark).

The writing circuit 16 writes data on the recording medium 3. The read circuit 17 reads data from the recording medium 3. The memory 18 stores information necessary for the processing of the CPU 12. Here, the memory 18 temporarily stores data (computer data / video data) obtained from the PC 1 and temporarily stores reproduction data read from the recording medium 3. And an error position storage unit 18b for storing an error position detected at the time of data reading.

The recording medium 3 comprises an optical disk. The recording medium 3 records computer data and video data. In this case, digital watermark information (Water Mark) is embedded in the video data as identification information for identifying the data type.

Next, the operation of the embodiment will be described. Here, a process for writing data (computer data / video data) sent from the PC 1 to the recording medium 3 by the DVD-RAM drive 2 and a process for reading data (computer data / video data) from the recording medium 3 are described. The processing will be described separately.

(A) Writing of data FIG. 2 is a flowchart showing a processing operation at the time of writing data in the embodiment. At the time of writing data, a write command is output from the PC 1 to the DVD-RAM drive 2 and data to be written is output.

Here, when outputting video data, the PC 1 embeds digital watermark information (Water Mark) for identifying a data type in a plurality of places in the video data.

The digital watermark information (Water)
Mark) embedding methods include, for example, a method of processing and embedding sample values such as waveforms and pixels, and a method of converting image data and audio data into frequency components and embedding them in specific frequency components. The invention is not limited to these schemes.

On the DVD-RAM drive 2 side, when data to be written and a write command are input via the I / F 11 (step A11), the data to be written is sequentially stored in the buffer 18a while passing through the write circuit 16. Then, the data is written to the recording medium 3 (step A12).

Here, usually, after the data is written, a verifying process for checking whether or not the data is correctly recorded is performed to improve the reliability. In the present embodiment, the verifying process at this time is performed. Is controlled according to the data type.

That is, when the data writing is completed (Yes in step A13), the CPU 12
It is checked whether or not digital watermark information (Water Mark) is embedded in the data written on the recording medium 3 through the Mark detecting unit 15 (Step A1).
4).

The digital watermark information can be detected by performing a process (reverse conversion) opposite to the embedding process on the data. In this case, data is stored in the buffer 18a.
, The presence or absence of digital watermark information can be detected.

As a result, the digital watermark information (Water
If the (Mark) is not embedded data (No in step A14), it can be determined that the data is computer data. Therefore, CPU1
2 executes a verification process on the computer data through the verification management unit 13 (step A).
15). That is, in the case of computer data, the reliability is emphasized and it is checked whether or not the data is correctly recorded. If the data is not correctly recorded, processing such as rewriting is performed.

On the other hand, digital watermark information (Water Ma)
rk) is embedded data (step A
14 (Yes), the data can be determined to be video data. In this case, the CPU 12 ends the processing here without performing the verification processing on the video data.

As described above, the digital watermark information (Water
(Mark), it is determined whether the data is computer data or video data, and the verification process is performed only in the case of computer data. As a result, it is possible to omit the verification process of the video data in which the continuity at the time of recording is more important than the reliability, and to shorten the time required for the writing process.

(B) Reading of data FIG. 3 is a flowchart showing a processing operation at the time of reading data in the embodiment. When reading data, a read command is output from the PC 1 to the DVD-RAM drive 2.

The DVD-RAM drive 2 reads this data from the recording medium 3 through the read circuit 17 by inputting this read command via the I / F 11 (step B11).

In this case, the data read unit is, for example, several sectors, and the data is read in a relatively long unit.
It is assumed that the data is sequentially stored in the buffer 18a shown in FIG. This is because since the DVD-RAM drive 2 does not know where the digital watermark information (Water Mark) is embedded in the data, it is necessary to read out and detect it in a relatively long unit.

Here, if an error occurs during the reading of data, a retry process for the error is usually performed at that time. In this embodiment, however, the data reading is continued as it is, and the data type is read after the reading is completed. Retry processing of the error part is performed according to.

That is, when an error is detected during data reading (Yes in step B12), the CPU 12 stores the error position in the error position storage unit 18b shown in FIG. 1 (step B13).

After the data reading is completed (Yes in step B14), the CPU 12
It is checked through the k detection unit 15 whether digital watermark information (Water Mark) is embedded in the data read from the recording medium 3 (step B1).
5). The detection of the digital watermark information at this time is performed by the inverse conversion processing as described above.

As a result, the digital watermark information (Water
If the (Mark) is not embedded data (No in step B15), it can be determined that the data is computer data. Therefore, CPU1
2 refers to the error position storage unit 18b to check whether an error has been detected during reading. If an error has been detected (Yes in step B16), retry processing for the error position is performed. Execute (Step B17).

That is, in the case of computer data, processing is performed such that the read range (for example, one sector) including the error position is read again with emphasis on reliability. If the error has not been resolved by this retry processing (Yes in step B18), the CPU 12 increments the internal retry counter (not shown) by one, and if the count value is equal to or smaller than the set value (step B19). Ye
s) and execute the retry process again (step B1)
7). Further, when the count value exceeds the set value, that is, when the error is not resolved even after retrying many times (No in step B19), the CPU 12 outputs an error notification to the PC 1 via the I / F 11. (Step B
21), end the process here.

On the other hand, digital watermark information (Water Ma)
rk) is embedded data (step B
15 (Yes), the data can be determined to be video data. In this case, regardless of the presence or absence of the error, the CPU 12 ends the processing here without performing the retry processing on the video data.

As described above, the digital watermark information (Water
Mark) to determine whether it is computer data or video data, and only in the case of computer data,
Perform retry processing for the error position. This allows
It is possible to omit the retry processing of the video data in which the continuity at the time of reproduction is more important than the reliability, and to shorten the time required for the reading processing.

Furthermore, by performing the retry processing not after the error is detected but immediately after reading the data, the processing time can be reduced as compared with the conventional retry method.

FIG. 4 shows this state. FIG. 4A is a diagram for explaining a retry method of the present invention, and FIG. 4B is a diagram for explaining a conventional retry method. In the conventional retry method, when an error is detected during data reading, reading of an error position is retried at that point. Therefore, data reading is interrupted every time an error is detected, and not only takes time to read data, but also, for example, in the case of video data, the reproduced video stops many times in the middle. Such a trouble occurs.

On the other hand, in the retry method of the present invention,
If an error is detected during data reading, the error position is stored and reading is continued as it is. Then, after the data reading is completed, the reading of the stored error position is retried. Therefore, the time required for the entire processing is shortened by the amount that data reading is not interrupted each time an error is detected as in the related art. In the case of video data,
Since the retry processing itself is not performed, the reproduced video is slightly disturbed at the error position, but there is no problem that the reproduction is stopped many times in the middle as in the related art.

Although the description with reference to FIG. 4 has been made from the viewpoint of the retry method, the following description will be shifted from the viewpoint and from the viewpoint of reliable detection of the digital watermark information itself.

"Digital watermarking" is a technique for arbitrarily writing, for example, an author or a title maker in data, and the information is not always stored at a specific position in video data. This is because the electronic watermark information may be embedded only in a part of one screen, or may be embedded finely as a whole.

Therefore, in the case where data is embedded in the middle of the data or the whole data is embedded in a series of data, the digital watermark information is embedded in the data unless some data is reproduced. It cannot be determined whether or not it has been

For example, if the digital watermark information is embedded at the position of W1 in FIG. 4A, the digital watermark information cannot be detected at the time when the error is detected. Also, when digital watermark information is embedded in the recording data as a whole and, for example, 70% or more of the data cannot be reliably detected without reading the digital watermark information, when the 40% of the data is read. When an error is detected in step (1), digital watermark information cannot be detected at that time.

However, even if a defect in the reproducing operation such as an error is found as in the present invention, it is possible to reliably detect the presence / absence of digital watermark information by reproducing all the series of data. Can be. As a result, the selection of the control for the subsequent data reading process can be reliably determined.

In the above embodiment, the DVD-RAM
Although the drive has been described as an example, the present invention
The present invention is not limited to the M drive, but can be applied to any device that performs recording and reproduction processing of at least two types of data having different data formats.

[0069]

As described above, according to the present invention, when performing recording / reproducing processing of at least two types of data having different data formats, the data type is determined according to the presence or absence of digital watermark information, and the determination result is obtained. , The verification process at the time of data writing and the retry process at the time of data reading are controlled. For example, when computer data and video data are recorded on the same recording medium, recording / reproducing is performed more than reliability. The verification processing and the retry processing for the video data that emphasizes the continuity of the data can be omitted, and the processing time can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a computer system using a data recording / reproducing device according to an embodiment of the present invention.

FIG. 2 is an exemplary flowchart showing a processing operation at the time of writing data in the embodiment.

FIG. 3 is a flowchart showing a processing operation at the time of reading data in the embodiment.

FIG. 4 is a diagram for comparing and explaining a retry method of the present invention and a conventional retry method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... PC 2 ... DVD-RAM drive 3 ... Recording medium 11 ... I / F 12 ... CPU 13 ... Verify management part 14 ... Retry management part 15 ... Water Mark detection part 16 ... Writing circuit 17 ... Reading circuit 18 ... Memory 18a ... Buffer 18b: Error position storage unit

──────────────────────────────────────────────────の Continued on front page (51) Int.Cl. ⁶ Identification code FI H04N 7/081

Claims (16)

[Claims] 1. A data recording / reproducing apparatus for performing recording / reproducing processing on a recording medium on which at least computer data and video data can be recorded, comprising: data reading means for reading data from the recording medium; Digital watermark detecting means for detecting digital watermark information from the obtained data; and when the digital watermark information is not detected by the digital watermark detecting means, it is determined that the data is computer data, and the digital watermark information is detected. If
A data recording / reproducing apparatus comprising: a determination unit that determines that the data is video data. 2. An error detecting means for detecting presence or absence of an error in read data; and read control means for executing a retry process for an error detected by the error detecting means, wherein the read control means performs the determination 2. The data recording / reproducing apparatus according to claim 1, wherein when the read data is determined to be video data, a retry process for the error detected by the error detecting means is not executed. 3. The writing control means executes a retry process for an error detected by the error detection means when the read data is determined to be computer data by the determination means. The data recording / reproducing apparatus according to claim 2, wherein 4. A data recording / reproducing apparatus for performing recording / reproducing processing on a recording medium on which at least computer data and video data can be recorded, comprising: data acquiring means for externally acquiring data to be written; Digital watermark detecting means for detecting digital watermark information from the data obtained by the means; and when the digital watermark information is not detected by the digital watermark detecting means, it is determined that the data is computer data. If is detected,
A data recording / reproducing apparatus comprising: a determination unit that determines that the data is video data. 5. A data writing means for writing data obtained by the data obtaining means on the recording medium, and if the determining means determines that the obtained data is video data, no verify processing is executed. 5. A data recording / reproducing apparatus according to claim 4, further comprising a writing control means for controlling the data recording / reproducing. 6. The method according to claim 1, wherein the write control means executes a verifying process after the data writing by the data writing means when the determination means determines that the acquired data is computer data. Item 6. A data recording / reproducing apparatus according to Item 5. 7. Data reading means for reading data from a recording medium, error position storing means for storing an error position when an error is detected during data reading by the data reading means, and reading the data. A data recording / reproducing apparatus, comprising: read control means for executing a retry process for an error position stored in the error position storage means after completion. 8. Digital watermark detecting means for detecting digital watermark information from the data read by the data reading means, wherein the read control means does not detect the digital watermark information by the digital watermark detecting means. 8. The data recording / reproducing apparatus according to claim 7, wherein a retry process is executed when the data recording / reproducing operation is performed. 9. A data recording / reproducing apparatus for performing recording / reproducing processing of at least two types of data having different data formats, comprising: data acquiring means for acquiring data to be written; and data obtained by the data acquiring means. Data writing means for writing data to a recording medium, writing control means for executing a verification process according to the type of the data after the data writing by the data writing means, data reading means for reading data from the recording medium, A data recording / reproducing apparatus, comprising: read control means for executing a retry process at the time of error according to the type of the data after the data is read by the read means. 10. The writing control unit according to claim 9, wherein the writing control unit determines whether the data is computer data or video data in accordance with the presence / absence of digital watermark information, and executes verification processing if the data is computer data. A data recording / reproducing apparatus according to claim 1. 11. The reading control means determines whether the data is computer data or video data according to the presence or absence of digital watermark information, and executes retry processing when an error occurs if the data is computer data. The data recording / reproducing device according to claim 9. 12. A recording medium on which computer data and video data are recorded, wherein the video data has digital watermark information for identifying a data type embedded therein. 13. A computer for outputting computer data or video data, embedding digital watermark information for identifying a data type in the video data and outputting the data, and inputting computer data or video data output from the computer. A data recording / reproducing device that determines a data type according to the presence or absence of the digital watermark information, and controls a verifying process when writing data and a retry process when reading data based on the determination result. A computer system characterized by the above-mentioned. 14. A data reproducing method for reproducing data from a recording medium in which digital watermark information is embedded in a series of data, wherein when an error is detected during the reproduction of the series of data, A data reproduction method, comprising: completing reproduction of the series of data without executing a retry process for the error; and detecting the digital watermark information from the reproduced series of data. 15. The data according to claim 14, wherein when the digital watermark information is detected, the reproduction of the next data following the series of data is continued without executing the retry processing related to the error. Playback method. 16. The data reproducing method according to claim 14, wherein when the digital watermark information is not detected, a retry process is performed on a portion where an error is detected.