JP2001291345A - Data recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the inhibitation of access of data having a real time characteristic. SOLUTION: An MPU 6 makes judgment as to whether the data having the real time characteristic exists in the data transferred from a DEMUX 1 to a memory 2 or not. If the data having the real time characteristic co-exists therein, the MPU 6 instructs retry prohibition or the limitation on the number of times to a controller 3 and allows the recording or reproducing to a data recording and reproducing section 9 to be executed. As a result, the delay of writing and reading out of the real time data is prevented by the retry of the non-real time data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data recording / reproducing apparatus suitable for recording / reproducing data for which writing and reading of data need to be completed within a predetermined time.

[0002]

2. Description of the Related Art In recent years, as a storage medium for digital data including image data, an HD having excellent random access has been developed.
Disk media such as (hard disks) have come to be used. In an HDD (hard disk drive) or an optical disk, data is recorded and reproduced by a pickup such as a magnetic head or an optical head tracing the disk surface along a track.

When recording and reproducing a disk in a computer or the like, a retry operation may be instructed to a disk drive in order to remove a data error. That is, when an error that cannot be corrected even by error correction by an error correction circuit occurs during a recording or reproducing operation, the recording or reproduction of the disc is performed until correct data or error-correctable data is recorded and reproduced. Repeat the reproduction.

The data recorded on the disk may be various data such as various program files, numerical files of spreadsheet software such as money, text files created by a word processor or an editor, video files of still images, and the like. Can be The retry operation enables accurate restoration of these files.

[0005] However, video files such as moving pictures, audio data files subjected to PCM (Pulse-Code Modulation) processing, and the like may be recorded on a disc. In this case, if the number of retry operations increases, it takes a long time to read reproduction data necessary for video output or audio output. That is, real-time recording and reproduction may not be possible due to the limitation of the bit rate during recording and reproduction of the disc. For this reason, the restored moving image or audio may be interrupted, and in the worst case, playback may not be possible.

Therefore, when reading and writing operations are performed on a data recording / reproducing apparatus such as an HDD, retry is prohibited for data (real-time data) that requires real-time performance. For reading and writing data that does not require real-time properties (non-real-time data), a method of performing a retry has been considered and used.

As an example in which data requiring real-time characteristics and data not requiring real-time characteristics coexist, there is data received by a digital broadcast receiver.

[0008] In digital broadcasting that is currently being performed, the M standard defined by HDISO / IEC13818 is used.
Video data and audio data compressed according to the PEG2 standard are stored in a 188-byte fixed-length transport stream packet (hereinafter, referred to as a TS packet), and are transmitted in a time-division multiplexed manner. Further, the data transmitted by digital broadcasting includes table data for extracting data relating to a desired program by performing demultiplexing processing on the receiver side, and TS packets storing data for data broadcasting and the like. It is multiplexed on the TS stream.

[0009] Of the data to be transmitted, video and audio data are required to be real-time, but table data and data for data broadcasting are not required to be real-time.

When such real-time data and non-real-time data are written in a mixed manner, access to the real-time data may be delayed due to retry for non-real-time data access. For example, if the reproduction of the video data is delayed, the image cannot be normally restored, and the screen display is broken.

[0011]

As described above, conventionally, when data that requires real-time performance and data that does not require real-time performance are mixedly recorded or reproduced, retry for non-real-time data is conventionally performed. As a result, there is a problem that data access of data having real-time properties may be delayed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and when data that requires real-time performance and data that does not require real-time performance are mixedly read and written, non-real-time data is required. It is another object of the present invention to provide a data recording / reproducing apparatus capable of preventing retry of non-real-time data from hindering access to real-time data by prohibiting or limiting the number of retries. .

In addition, the present invention prohibits automatic retry of a disk medium by a controller and re-accesses non-real-time data while monitoring idle time, thereby enabling access to real-time data. It is an object of the present invention to provide a data recording / reproducing apparatus capable of reducing non-real-time data errors without hindrance.

[0014]

A data recording / reproducing apparatus according to the present invention comprises: a recording / reproducing means capable of retrying at the time of recording data and reproducing the recorded data; a write data to be written to the recording / reproducing means; Determining means for determining whether or not data requiring real-time is mixed in read data read from the reproducing means; and determining that the write data and read data do not include data requiring real-time property. If it is determined, retry of the recording / reproducing means is permitted for data that does not require real time in the write data and read data, and when it is determined that data that requires real time is mixed, ,
Control means for prohibiting or limiting the number of retries of the recording / reproducing means for data not requiring the real-time property is provided.

In the present invention, the judging means judges whether or not the data recorded by the recording / reproducing means and the data to be reproduced are mixed with data requiring real-time property. When data requiring real-time properties are mixed, the control means prohibits or limits the number of retries for data not requiring real-time properties, and causes the recording / reproducing means to perform recording and reproduction.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of a data recording / reproducing apparatus according to the present invention. In this embodiment, a transport (TS) in which real-time data and non-real-time data are mixed
An example in which the present invention is applied to an apparatus for recording and reproducing a stream will be described.

A transport stream is input to a demultiplexer (DEMUX) 1. FIG. 2 is an explanatory diagram for describing an input TS stream.

As shown in FIG. 2, in the TS stream, not only video data and audio data but also various data, for example, data including a time stamp for reproduction, are arranged in packet units (TS packets) having a length of 188 bytes. Transmitted. As data including a time stamp, for example, PES (Pa
cketized Elementary Stream).

As shown in FIG. 2, the TS packet has a header and an adaptation field followed by data bytes. The transport packet corresponds to a multi-program (channel), and a packet of a desired program can be selected from a plurality of programs transmitted in a time-division manner at the time of decoding. For this selection, a PID, which is an ID for packet identification, is added to the header.

In order to obtain PID information of TS packets such as video and audio constituting a desired program, TS packets including table information called SI (service information) are also multiplexed in the TS stream.
Further, in the TS stream, a PMT (Program Map Tabe) packet including table information in which a list of PIDs such as video and audio constituting the program is described is also multiplexed.

In order to extract a packet of a desired program,
First, the receiver acquires table information called PAT (Program Association Table) identified by PID = 0 from the TS stream. The PAT describes the PID of the PMT corresponding to the program number, and the receiver refers to this table information to find out the PID of the PMT corresponding to the desired program and obtain the PMT. The receiver is
A packet of video data and audio data of a desired program is extracted with reference to the table information of the PMT, and decoding is performed.

In FIG. 1, DEMUX1 is a DMA.
(Direct memory access) function
Under the control of U6, the extracted data can be transferred to the memory 2. The MPU 6 reads information from the memory 2 and controls the demultiplex processing of the DEMUX 1. Desired data is separated and extracted by the DEMUX1 and the MPU6.

Specifically, the DEMUX 1 is controlled by the MPU 6 to first extract a packet with PID = 0 from the TS stream to obtain a PAT. The extracted PAT is transferred to the memory 2. The MPU 6 reads the PAT stored in the memory 2 and knows the PID of the PMT packet corresponding to the desired program by referring to the PAT.
Instruct X1 to extract the PMT packet.

[0024] DEMUX1 converts the PM from the TS stream.
T is extracted and transferred to the memory 2 similarly to PAT. M
The PU 6 refers to the PMT stored in the memory 2 to identify the PID of the video, audio and the like constituting the program and the stream type, and controls the extraction of the DEMUX1 data. The MPU 6 can determine whether or not the data to be recorded includes real-time data by referring to the PMT information.

The DEMUX 1 is controlled by the MPU 6,
The video data and the audio data of the channel selected by the user, and the table data and other non-real-time data accompanying these data are extracted and output to the memory 2.

The DEMUX 1 can output the audio data extracted under the control of the MPU 6 to the audio decoder 4 and can output the video data to the video decoder 5.

The audio decoder 4 decodes the input audio data and outputs a digital audio signal to an audio digital / analog converter (hereinafter, audio ADC) 7. The audio ADC 7 converts an input digital signal into an analog signal and outputs an analog audio output.

The video decoder 5 decodes the input video data and outputs a digital video signal to the video encoder 8. The video encoder 8 converts the decoded video data in accordance with a display system, for example, the NTSC system. The video signal from the video encoder 8 is supplied to a mixer / selector 10.

The MPU 6 reads non-real-time data from the memory 2, controls the MPEG decoder 5 using the read non-real-time data, creates display data based on the input non-real-time data, and outputs it to the mixer / selector 10. I do. Mixer / selector 1
0 mixes the output of the video encoder 8 and the output of the MPU 6 and outputs it as a video output.

The MPU 6 has a DMA function, and transfers the data written in the memory 2 to the controller 3 after modifying the table data such as PAT as necessary. I have.

The controller 3 controls recording and reproduction of the data recording / reproducing unit 9. For example, the data recording / reproducing unit 9
Is an HDD, the controller 3
Alternatively, the controller is an IDE standard controller. Controller 3
Can write data from the memory 2 to the data recording / reproducing unit 9 using a protocol corresponding to the data recording / reproducing unit 9 and read data recorded in the data recording / reproducing unit 9. The MPU 6 can transfer data reproduced by the controller 3 to the memory 2 by a DMA function or the like. In addition, DEMUX
1 can be controlled by the MPU 6 to take in the data stored in the memory 2 by the DMA function.

The MPU 6 is, as described above, a DEMUX
It is determined whether the data supplied from 1 to the memory 2 is real-time data. In the present embodiment, the MPU 6 controls the controller 3
At the time of recording / reproducing to / from the data recording / reproducing section 9, the presence / absence of retry and the number of retry are specified.

That is, when the data recorded in the data recording / reproducing unit 9 and the data reproduced from the data recording / reproducing unit 9 include real-time data based on the PMT, the MPU 6 performs not only real-time data but also non-real-time data. The retry is prohibited or the number of times is limited. The MPU 6 always prohibits or limits the number of retries for real-time data.

Accordingly, it is possible to prevent the writing and reading of the real-time data from being delayed due to the time required for retrying the writing and reading of the non-real-time data, thereby preventing the memory 2 from overflowing or underflowing.

When limiting the number of retry operations, the MPU 6 sets the data amount of real-time data and non-real-time data, the write / read rate in the data recording / reproducing unit 9, the capacity of the memory 2, and the
The number of retries is set in consideration of the processing capability of U6.

Next, the operation of the embodiment configured as described above will be described with reference to the flowchart of FIG.

First, an operation for recording data of a desired program in the data recording / reproducing section 9 will be described.

A transport stream having a format shown in FIG. 2, for example, is input to DEMUX1.
The MPU 6 first sends the PA with PID = 0 to the DEMUX1.
The T packet is extracted and transferred to the memory 2. MPU
6 reads out the PAT stored in the memory 2;
By referring to T, the PID of the PMT packet corresponding to the desired program is known, and the DEMUX 1 is instructed to extract the PMT packet.

The DEMUX 1 extracts a PMT packet and sends it to the memory 2. The MPU 6 refers to the table information of the PMT to extract the video data and audio data of the channel selected by the user, the accompanying table data, and other non-real-time data. The separated and extracted data is transferred to the memory 2 by the DMA function of the DEMUX1.

The MPU 6 modifies the table data such as PAT as necessary. The MPU 6 transfers the data for which recording has been instructed by the user from the memory 2 to the controller 3, and instructs the controller 3 to record on the data recording / reproducing unit 9.

In this embodiment, at the time of writing, the MPU 6 also instructs the controller 3 on the presence / absence of a retry and the limitation on the number of retries. MPU 6 is shown in FIG.
In step S1, the PID of video, audio, etc. constituting a program is referred to by referring to the table information of the PMT.
And stream type. The MPU 6 determines whether the data written by the controller 3 includes real-time data (step S2).

Now, it is assumed that the data written by the controller 3 does not include real-time data. In this case, the MPU 6 shifts the processing to step S4,
Set retry as usual. As a result, the controller 3 writes the data transferred from the memory 2 to the data recording / reproducing unit with retry.

On the other hand, when real-time data is mixed in the recording data, the MPU 6
Then, the process goes to 3 to instruct the controller 3 to perform no retry or limit the number of retries. In this case, the controller 3 performs recording on the data recording / reproducing unit 9 without retry or limiting the number of retries.

In this case, no retry operation is performed or the number of retries is limited for both real-time data and non-real-time data. Therefore, the time required for writing the non-real-time data is a time corresponding to the data amount, and the retry operation does not delay the writing of the real-time data.

Next, the operation of reproducing data from the data recording / reproducing section 9 and viewing recorded data will be described.

The MPU 6 gives an instruction to the controller 3 to read data from the data recording / reproducing unit 9. M
The PU 6 converts the data read by the controller 3 into a DMA.
The data is transferred to the memory 2 by a function or the like. The MPU 6 first reads the PAT and PMT data.

In step S 1 of FIG. 3, the MPU 6 sets the PID =
PMT corresponding to the program to be reproduced by referring to packet 0
Next, the PMT is read, and the PMT is read to obtain the PIDs of the video and audio constituting the program to be reproduced and the identification information of the stream type.

When information used for reproducing a program such as PAT and PMT is stored in a unique format at the time of recording, the information may be referred to.

The MPU 6 determines whether or not the reproduction data includes real-time data by referring to the stream type identification information (step S2).

If the reproduction data does not include the real-time data, the data is reproduced by the usual retry operation in step S4.

Here, it is assumed that the reproduction data includes real-time data. In this case, MPU6
Instructs the controller 3 to perform no retry or to limit the number of retries. Thus, when reading data from the data recording / reproducing unit 9, the controller 3 prohibits or limits the number of retries for both non-real-time data and real-time data.

As a result, the reading of the non-real-time data is in accordance with the amount of data, the reading of the real-time data is delayed by the retry processing of the non-real-time data, and the decoding becomes discontinuous due to the underflow of the memory 2 and the reproduction is performed. It is possible to prevent the image from being broken.

The data read from the data recording / reproducing unit 9 is transferred to the memory 2 by the DMA function of the MPU 6. Of the data transferred to the memory 2, table information (non-real-time data) is held in the memory 2, and the MPU 6 refers to these data as needed.

Other data (real-time data) transferred to the memory 2 is taken into the DEMUX1 by the DMA function of the DEMUX1. The data transferred to DEMUX1 is a TS stream packet,
The EMUX 1 depackets the TS stream packet, outputs video data to the MPEG decoder 5, and outputs audio data to the audio decoder 4.

The video data is output to the video encoder 8 after being decoded by the MPEG decoder 5. The decoded output is encoded by the video encoder 8 according to the format of the display device. The audio data is decoded by the audio decoder 4, converted into an analog signal by the audio DAC 7, and then output as an audio output.

On the other hand, non-real-time data other than table information is decoded by the MPU 6. MPU
6, the decoding result is converted into display data. The mixer / selector 10 outputs the output of the video encoder 8 and M
The output from the PU 6 is mixed and output as a video output.

By supplying the audio output from the audio DAC 7 and the video output from the mixer / selector 10 to the monitor device, the reproduced image of the program recorded in the data recording / reproducing section 9 can be restored.

As described above, in this embodiment, when it is detected that real-time data is mixed, retry is prohibited or the number of times is limited, and real-time data read / write is performed by retry processing when reading / writing non-real-time data. It is possible to prevent the writing from being delayed. As a result, the memory does not overflow or underflow for writing and reading non-real-time data, and it is possible to prevent breakdown of images and sounds even during reproduction of recorded data.

In the embodiment of FIG. 1, an example has been described in which the retry operation is prohibited or the number of times is restricted for both real-time data and non-real-time data. You may make it.

In the case where real-time data is mixed in the write or read data during the writing or reading of the non-real-time data, the non-real-time data is read from the point in time when it is detected that the real-time data is mixed. The retry may be prohibited or the number of times may be limited.

FIG. 4 is a flowchart showing an operation flow employed in another embodiment of the present invention. The hardware configuration in the present embodiment is the same as in FIG. FIG.
In FIG. 6, the same steps as those in FIG.

In the above embodiment, at least non-real-time data is prohibited from being retried or limited in the number of times when data is read from the data recording / reproducing unit. Therefore, there is a possibility that a read error has occurred in the read non-real-time data.

Therefore, in the present embodiment, the MPU 6 checks the read data transferred to the memory 2 for error correction information added to the read data in advance, and when a read error is detected, By reading again from the data recording / reproducing unit without retry or with a limit on the number of retries, the reliability of the read non-real-time data can be improved.

Next, the operation of the embodiment configured as described above will be described.

The MPU 6 refers to the table information held in the memory 2 when reproducing data from the data recording / reproducing section 9 in the same manner as the operation flow in FIG. Further, it is the same as step S2 in FIG. 3 in that it is determined in step S12 in FIG. 4 whether or not real-time data is mixed in the reproduced data.

If real-time data does not exist in the reproduced data, a read process with a retry operation is performed in step S14. When it is detected that real-time data is present in the reproduced data, a retry operation is performed in step S13. The reading process is performed with the prohibition or the number of times being restricted, similarly to FIG.

In the present embodiment, in step S15, the MPU 6 determines whether or not a read error has occurred in the non-real-time data transferred to the memory 2.
The determination is made using the error correction information. If an error has occurred in the non-real-time data, the MPU 6 determines in the next step S16 whether or not there is room for rereading.

If the read data amount of the real-time data or the non-real-time data is large and there is no free time for rereading the non-real-time data in which an error has occurred, the MPU 6 waits until a free time occurs. When detecting that a vacant time for rereading the non-real-time data has occurred, the MPU 6 instructs the controller 3 to re-read the non-real-time data using the vacant time (step S13). Also in this case, the MPU 6 instructs the controller 3 to prohibit retry or limit the number of times.

As described above, in the present embodiment as well, the read processing of the controller 3 is prohibited from being retried or the number of times is restricted. However, if an error occurs in the non-real-time data, the MPU 6
, The re-reading is performed in a state where the idle time is not retried or the number of times is limited. Accordingly, it is possible to prevent a delay in reading the real-time data due to the retry processing of the non-real-time data, and it is possible to reduce a reading error of the non-real-time data by performing the re-read processing using the idle time.

FIG. 5 is a flowchart showing an operation flow employed in another embodiment of the present invention. The hardware configuration in the present embodiment is the same as in FIG. FIG.
In FIG. 6, the same steps as those in FIG.

The embodiment is obtained by applying the embodiment of FIG. 4 at the time of writing data. That is, in the present embodiment, the MPU 6 controls the controller 3 to read out the write data recorded in the data recording / reproducing unit 9 from the controller 3, and transfers the read data to the memory 2. The MPU 6 checks error correction information added to the read data in advance, and if a read error is detected, the MPU 6 does not retry the data recording / reproducing unit 9 by the controller 3 or writes the data with the number of retries. I do. As a result, the reliability of the written non-real-time data is improved.

Next, the operation of the embodiment configured as described above will be described.

The MPU 6 refers to the table information held in the memory 2 when recording data in the data recording / reproducing section 9 (step S1), as in the operation flow of FIG. In step S22 in FIG. 5, it is also determined whether or not real-time data is mixed in the recorded data.
This is the same as step S2 in FIG. Further, when real-time data is not mixed in the recorded data, a write process with a retry operation is performed in step S24. When it is detected that real-time data is mixed in the reproduced data, the prohibition or number of retries is performed in step S23. The writing process is performed in a limited manner as in FIG.

In the present embodiment, in step S25, the MPU 6 controls the controller 3 to read out the once written data and transfer it to the memory 2 to determine whether an error has occurred in the transferred non-real-time data. Is determined using the error correction information. If an error has occurred in the non-real-time data, the MPU
No. 6 determines in the next step S26 whether or not there is room for rewriting.

If the amount of data to be written for real-time data or non-real-time data is large and there is no free time for rewriting non-real-time data in which an error has occurred, the MPU 6 waits until a free time occurs. When detecting that a non-real-time data rewriting free time has occurred, the MPU 6 uses this free time to instruct the controller 3 to re-write the non-real-time data (step S23). Also in this case, the MPU 6 instructs the controller 3 to prohibit retry or limit the number of times.

As described above, also in the present embodiment, the retry is prohibited or the number of times is limited in the writing process of the controller 3. However, if an error occurs in the non-real-time data, the MPU 6
, The rewriting is performed in a state where the idle time is not retried or the number of times is limited. Accordingly, it is possible to prevent a delay in reading real-time data due to the retry processing of the non-real-time data, and to reduce a reading error of the non-real-time data by performing the rewriting process using the idle time.

[0077]

As described above, according to the present invention, it is possible to prevent access to real-time data from being hindered by retry of non-real-time data, and to monitor non-real-time data while monitoring idle time. By performing real-time data re-access, there is an effect that errors in non-real-time data can be reduced without obstructing access to real-time data.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a data recording / reproducing apparatus according to the present invention.

FIG. 2 is an explanatory diagram showing a stream in which real-time data and non-real-time data are mixed.

FIG. 3 is a flowchart illustrating the operation of the embodiment.

FIG. 4 is a flowchart showing an operation flow employed in another embodiment of the present invention.

FIG. 5 is a flowchart showing an operation flow employed in another embodiment of the present invention.

[Explanation of symbols]

1 ... DEMUX, 2 ... Memory, 3 ... Controller, 6 ...
MPU, 9: Data recording / reproducing unit.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G06F 3/06 305 G06F 3/06 305K G11B 20/10 301 G11B 20/10 301Z H04N 5/76 H04N 5 / 76 Z (72) Inventor Noriya Sakamoto 8th Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Inside the Toshiba Yokohama Office (72) Inventor Atsushi Hirota 8th Shin-Sugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Inside the Toshiba Yokohama Office, Ltd. F term (reference) 5B065 BA01 CA12 CC08 EA04 5C052 AA01 DD04 5D044 AB10 BC01 BC06 CC04 DE42 GK12

Claims (4)

[Claims] 1. A recording / reproducing means capable of performing a retry at the time of recording data and reproducing the recorded data, and data requiring real-time processing are written data to be written to the recording / reproducing means and read data read from the recording / reproducing means. A judging means for judging whether or not the data is mixed, and when the judging means judges that the data requiring real-time is not mixed in the write data and the read data, Retry of the recording / reproducing means is permitted for data that does not require real-time property, and if it is determined that data that requires real-time property is mixed, the data that does not require real-time property is recorded. Control means for prohibiting retry of the reproduction means. The data recording and reproducing apparatus. 2. A recording / reproducing means capable of performing a retry at the time of recording data and reproducing the recorded data, and data requiring real-time processing are written data to be written to the recording / reproducing means and read data read from the recording / reproducing means. A judging means for judging whether or not the data is mixed, and when the judging means judges that the data requiring real-time is not mixed in the write data and the read data, The retry of the recording / reproducing means is permitted for data that does not require real-time property. If it is determined that data that requires real-time property is mixed, the recording / reproducing is performed for data that does not require real-time property. Control means for limiting the number of retry of the means. The data recording and reproducing apparatus to be. 3. The control means, when it is determined that data requiring real-time properties are mixed, real-time data in the data written by the recording / reproducing means and the data read from the recording / reproducing means. Error detection means for detecting a write and read error for data that does not need to be read, and when the error detection means indicates that there is an error, the recording / reproduction means for the data having an error 3. The apparatus according to claim 1, wherein the retry is prohibited and rewriting or rereading is performed.
The data recording / reproducing apparatus according to any one of the above. 4. The control means, when it is determined that data requiring real-time properties are mixed, real-time data in the data written by the recording / reproducing means and the data read from the recording / reproducing means. Error detection means for detecting a write and read error for data that does not need to be read, and when the error detection means indicates that there is an error, the recording / reproduction means for the data having an error 2. A rewriting or rereading operation is performed by limiting the number of retries.
Or the data recording / reproducing apparatus according to any one of 2.