JPH09116864A - Mpeg2 data transfer method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the MPEG2 data transfer method conducting stream processing in which a transfer processing time of MPEG2 to an ATM channel is considerably reduced and reproduction is conducted accurately. SOLUTION: MPEG2 data are transferred to a synchronization standard time read board 4 via a PCI bus 3 from a laser disk 9a storing the MPEG2 data. The board 4 extracts synchronization standard time data and the MPEG2 data are read from a tentative storage section according to the time calculated as above and transferred to an ATM channel board 5 via the PCI bus 3. In comparison with a conventional transfer method, while the MPEG2 transfer data are subject to stream processing, the transfer processing time is considerably reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
Packet-based MPEG2 data is transferred to ATM (asynch
ronous transfer mode) An MPEG2 data transfer method for transferring to a line.

[0002]

2. Description of the Related Art The architecture has both advantages of circuit switching and packet switching, and can flexibly support transmission speeds from megabit to gigabit in a data unit of a short packet length (fixed cell 53 bytes) and exchange. AT, which is a low-delay and high-speed network for multimedia communication, where most of the processing is performed by hardware
The M network is attracting attention. The packet length of this ATM network is 48 bytes of actual data, and a fixed length (53 bytes) of ATM cell is formed by adding a header to this. Therefore, 18 is required for transferring MPEG2 data.
By adopting a demultiplexing method using a transport packet having a relatively short packet length of 8 to 376 bytes, the compatibility with the ATM network is achieved.

As a result, a transport packet of MPEG2 data can be transmitted while being carried on a plurality of ATM cell fixed lengths (53 bytes). Under these circumstances, there is a demand for a technique for transferring MPEG2 data, which compresses a moving image having a large amount of data at a high compression rate, to an ATM line at high speed. MPEG stored in a laser disk on a personal computer or the like on the ATM line.
In the case of transferring two data, conventionally, first, MPEG2 data is transferred to the main memory via SCSI under the control of the CPU. It has been considered that the CPU, after performing data processing by software processing, performs an operation of reading from the main memory and transferring to the ATM line.

[0004]

SUMMARY OF THE INVENTION In the above transfer method, M
Since it takes a lot of time to transfer the PEG2 data to the ATM line, there is a drawback that the request for high speed transfer cannot be met. An object of the present invention is to provide an MPEG2 data transfer method for significantly reducing the transfer processing time of MPEG2 data to an ATM line by a transport packet method and performing stream processing for reproducing accurately with respect to time. It is in.

[0005]

In order to achieve the above object, the MPEG2 data transfer method according to the present invention is an MP in which a demultiplexing method using transport packets is adopted.
The MPEG2 data is transferred from the storage medium storing the EG2 data to the synchronization standard time reading board via the PCI bus, and MP is stored in the temporary storage unit of the synchronization standard time reading board.
When storing the EG2 data, the synchronization standard time data is extracted from the MPEG2 data, and the extracted synchronization standard time data and the address of the temporary storage unit in which the synchronization standard time data is stored are stored separately from the MPEG2 data. Then, a read time interval is calculated from the extracted standard time data for synchronization and the address, MPEG2 data is read from the temporary storage unit in accordance with the read time interval, and transferred to the ATM line board via the PCI bus. I am doing it. Further, in the transfer method according to the present invention, when MPEG2 data is read from the storage medium, it is read on a bus different from the PCI bus, and then converted by a bridge circuit to be connected to the PCI bus and connected to a standard time reading board for synchronization. It is configured to transfer to.

According to the above method, compared with the conventional transfer method, the transfer processing time can be significantly shortened while the MPEG2 transfer data is stream processed.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows MPEG2 according to the present invention.
It is a block diagram which shows the Example of a data transfer method, and is a system block diagram of the personal computer comprised based on this transfer method. This drawing shows only the part directly related to the present invention. A CPU 1 that controls the entire system based on a program is connected to a system bus 2. The PCI bus 3, which is a high-speed bus, is connected to the system bus 2 via the bridge circuit 5.

The bridge circuit 5 includes a system bus 2 and a PC.
It is for converting the mutual data formats of the I-bus 3. The PCI bus 3 has a PCR (program clock referenc
e, standard time for synchronization) The leader board 4 and the ATM board 11 are connected. PCR is a synchronization standard time for setting and configuring the value of STC (reference synchronization information), which is a time reference, in the encoder side in an MPEG system decoder including a video and audio decoder. It is defined as information. Furthermore, via the bridge circuit 6, EISA (extended industry standard architect
ure) Bus 7 is connected. The bridge circuit 6 is a PC
It is for converting the mutual data format of the I-bus 3 and the EISA 7.

A laser disk device 9 and a hard disk device 10 are daisy chain connected to the EISA 7 via a SCSI interface circuit 8 by a connection cable 12. In this example, MPEG2 data is stored in the laser disk 9a loaded in the laser disk device 9, and the transport packet of this MPEG2 data is transferred to the ATM board 11 via the PCR reader board 4.
To be forwarded to.

FIG. 2 is a block diagram showing details of the circuit configuration on the PCR leader board 4. The PCI bus 3 and the internal bus 19 are connected via the PCI interface circuit 13. The circuit on the PCR leader board is PCI
The interface circuit 13 is included, and is composed of an MPEG2 data storage processing unit 14, a PCR processing unit 15, a control unit 18, and a soft interface unit 20. The soft interface unit 20 includes a register and the like for exchanging commands between the CPU 1 and the control unit 18. MPEG
The 2 data storage processing unit 14 includes a temporary storage unit having a capacity for a plurality of pages, and the PCI interface circuit 13
The MPEG2 data sent via the is stored in the temporary storage unit according to the address control.

MP is stored in all page storage units of the temporary storage unit.
When EG2 is stored, reading is performed in page units in accordance with the time interval calculated by PCR, and when the read memory unit in page units becomes empty, the next MPEG2 data is continuously stored in the empty memory unit. P
The CR processing unit 15 is composed of a PCR extracting unit 16 and a PCR storing unit 17, and the PCR extracting unit 16 detects the PCR data from the MPEG2 transport packet sent from the laser disk 9a and performs the extracting operation. I do. The PCR storage unit 17 stores the extracted PCR data and the address of the temporary storage unit that stores the extracted PCR data.

The control unit 18 waits for the MPEG2 data to be stored on the basis of the command held in the soft interface unit 20, reads the PCR data and the address from the PCR storage unit 17, and uses the PCR data and the address to store the MPEG2 data. The read time interval is calculated. The control unit 18 controls the MPE at the calculated time intervals.
The MPEG2 data between the PCRs is read from the G2 data storage processing unit 14, and the PCI interface circuit 13, PC
Transfer to the ATM board 11 via the I-bus 3.

FIG. 3 is a diagram for explaining the operation of the MPEG2 data transfer method according to the present invention. Hereinafter, description will be given with reference to FIGS. 1 and 2 as well. CPU1
A data transfer instruction is sent to the SCSI interface circuit 8. The data transfer execution request is also sent to the soft interface means 20 of the PCR leader board 4. The control unit 18 of the PCR leader board 4 sends a page transfer request to the CPU 1 when the environment settings necessary for the transfer are set and the preparation for writing the MPEG2 data is completed. The CPU 1 instructs the SCSI interface circuit 8 to transfer page data, and MPEG2 data is read from the laser disk 9a based on the instruction and transferred to the PCR leader board 4 in page units (for example, 256 Kbytes) ().

In the PCR leader board 4, the MPEG2 data is sent to the MPEG2 data storage processing section 14, and the MPEG2 data is stored in the temporary storage section. At the same time, the PCR data is extracted from the MPEG2 data by the PCR processing unit 15, and the PCR data and the address of the temporary storage unit storing the PCR data are stored in the PCR storage unit 17. PCR
The PCR data and its address stored in the storage unit 17 are read out, and the control unit 18 calculates the time interval. When the MPEG2 data storage processing unit 14 becomes full, data is read page by page and transferred to the ATM board 11 via the PCI bus 3. ATM
Transfer to the board 11 is controlled by the PCR under the control of the control unit 18.
This is performed by the leader board 4 directly writing data in the buffer of the ATM board 11 as a master.

Data is read from the MPEG2 data storage processing unit 14 in accordance with the calculated time interval.
When the data in page units is transferred, the MPEG2 data storage processing unit 14 has a vacant space corresponding to it, so that the C
A page transfer request is issued to PU1, and thereby MPEG2 data is written in the free space of the temporary storage unit. By repeating this operation, when all the planned MPEG2 data (the total number of data is written in the soft interface means 20) is transferred to the ATM board 11, the control unit 18 sends a completion report to the CPU 1.

The CPU 1 then switches to the PCR leader board 4
The status of the PCR leader board 4 can be known by reading the status information sent from the. ATM board 1
In No. 1, ATM2 is processed by processing MPEG2 data accumulated in the buffer into a fixed-length cell of 53 bytes, for example.
It is converted into information and sent to the ATM line. In the above embodiment, when transferring from the PCR leader board 4 to the ATM board 11, the PCR leader board 4 is used as a master for the ATM.
An example of directly writing to the buffer of the board 11 has been described,
The PCR reader board 4 can also be operated so that the DMA function of the ATM board 11 is set and activated as a master, and then the data is read from the temporary storage unit as a slave.

[0017]

As described above, according to the present invention, a demultiplexing method using transport packets is adopted.
The MPEG2 data is transferred from the storage medium storing the PEG2 data to the synchronization standard time reading board via the PCI bus, and MPE is stored in the temporary storage unit of the synchronization standard time reading board.
When storing the G2 data, the synchronization standard time data is extracted from the MPEG2 data, and the extracted synchronization standard time data and the address of the temporary storage section in which the synchronization standard time data is stored are stored separately from the MPEG2 data.
The read time is calculated from the extracted standard time data for synchronization and the address, and the MPEG2 data is read from the temporary storage unit according to the read time and transferred to the ATM line board via the PCI bus. Therefore, compared with the conventional transfer method, ATM
There is an effect that the transfer time of the MPEG2 data to the line can be greatly shortened and a MPEG2 data transfer method suitable for a high speed ATM line can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an MPEG2 data transfer method according to the present invention.

FIG. 2 is a block diagram showing a circuit configuration of the PCR leader board of FIG.

FIG. 3 is a diagram for explaining the operation of the MPEG2 data transfer method according to the present invention.

[Explanation of symbols]

 1 ... CPU 2 ... System bus 3 ... PCI bus 4 ... PCR leader board 5, 6 ... Bridge circuit 7 ... EISA bus 8 ... SCSI interface circuit 9 ... Laser disk device 10 ... Hard disk device 11 ... ATM board 12 ... Daisy chain connection cable 13 ... PCI interface circuit 14 ... MPEG2 data storage processing unit 15 ... PCR processing unit 16 ... PCR extraction unit 17 ... PCR storage unit 18 ... Control unit 19 ... Internal bus 20 ... Soft interface means

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H04Q 3/00 H04N 7/13 Z

Claims (2)

[Claims] 1. An MPEG2 data is transferred from a storage medium storing a transport packet of MPEG2 data to a PC.
The data is transferred to the synchronization standard time reading board via the I bus, and the MPEG is stored in the temporary storage unit of the synchronization standard time reading board.
When storing two data, the synchronization standard time data is extracted from the MPEG2 data, and the extracted synchronization standard time data and the address of the temporary storage unit in which the synchronization standard time data is stored are stored separately from the MPEG2 data. Then, a read time interval is calculated from the extracted standard time data for synchronization and the address, MPEG2 data is read from the temporary storage unit in accordance with the read time interval, and transferred to the ATM line board via the PCI bus. MPEG2 data transfer method. 2. When reading MPEG2 data from the storage medium, the PCI2 is read by a bus different from the PCI bus, and then converted by a bridge circuit to obtain PCI.
2. The MPEG according to claim 1, wherein the MPEG is connected to a bus and transferred to a standard time reading board for synchronization.
2 Data transfer method.