JPH10243354A - Moving image reproducing device and computer system having moving image reproducing device as peripheral device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a moving image reproducing device capable of reducing the load of a CPU and suppressing the adverse effect to be exerted to other application by executing the playback and reverse reproduction of a digital moving image by hardware. SOLUTION: When a reverse reproduction mode or a playback reproduction mode is instructed from the external, data stored in a buffer memory 17 are successively read out respectively in a new order and an old order. A hardware circuit consisting of a buffer memory control circuit 16 for adding time information for disabling a moving image reproducing circuit 13 from being conscious of reverse reproduction or playback reproduction to read data and supplying the time information to an input selector and an input data selector 18 for selecting one input and supplying the selected input to the circuit 13 in accordance with the execution or reset of the mode is added. The playback reproduction and reverse reproduction of a digital moving image are executed by the hardware circuit. Consequently the throughput of the system can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving picture reproducing apparatus for reproducing digital moving pictures conforming to the standards such as MPEG2 and a computer system having the moving picture reproducing apparatus as a peripheral device.

[0002]

2. Description of the Related Art A digital set-top box is essential for realizing video on demand. The digital signal received via the network is demodulated, the compressed video data is extracted, decoded, and displayed on a television receiver. The key to the design of this set-top box is MPEG2 (Moving Picture)
e Experts Group Phase 2), a decoding LSI, a graphics LSI, a demodulation LSI for digitally modulated signals, a microprocessor for controlling the system, and the like. Such components are also indispensable for DVD players. Set Top
Box and DVD (Digital Video Di
sk) The difference from the player depends on whether it has a network interface or a reproduction circuit from an optical pickup.

[0003] In the field of personal computers or workstations, which are the mainstay of multimedia equipment, full-motion, full-screen (moving picture display of the same image quality as that of the current TV picture, 30 frames / (Reproduction of seconds required). When data encoded by MPEG2 is decoded by a microprocessor, PCI (Peripera)
l Component Interconnect)
Moving image data must be written to the frame buffer using an equal input / output bus. The transfer of the decoded full-motion, full-screen MPEG2 moving image data requires a transfer speed of 15 to 20 Mbytes / sec.
Traffic due to data reading from the DVD device or access to the hard disk device is added.

In the above-described digital moving picture reproducing apparatus such as a personal computer, a workstation, a set top box or a DVD player, the special reproduction such as the playback reproduction and the reverse reproduction of the digital moving picture has been realized by software. Things. FIG. 4 shows an internal configuration diagram of a conventional moving image reproducing apparatus.
FIG. 5 is a flowchart showing the operation of the moving image reproducing apparatus.
FIG. 6 is a flowchart showing processing by software. In other words, the conventional moving image reproducing apparatus performs only a normal reproducing operation, and the software (CPU) changes the order of moving image data written in the memory, and adds new time information to the data so that the moving image data can be viewed. The special reproduction of the hanging digital video was being processed.

[0005]

As described above, in the conventional digital moving image reproducing apparatus, the playback reproduction or the reverse reproduction of the digital moving image is realized by software. This has contributed to a decrease in throughput. During that time, the CPU is occupied, which adversely affects the operation speed of other applications. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and performs playback and reverse playback of digital moving images by hardware to reduce the load on the CPU and to reproduce moving images without adversely affecting other applications. It is intended to provide a device.

[0006]

SUMMARY OF THE INVENTION A moving picture reproducing apparatus according to the present invention includes a moving picture reproducing circuit for taking in compressed digital moving picture data and converting it into digital moving picture data in a color space format. The buffer memory for temporarily storing the compressed digital moving image data to be fetched, and the data stored in the buffer memory when the reverse playback mode or the playback playback is instructed from the outside, in the order of newest and oldest, respectively. A buffer memory control circuit which sequentially reads out the data, adds time information to the moving image reproducing circuit so as to make the moving image reproducing circuit unconscious of reverse reproduction or playback reproduction, and supplies the data to the input selector; And both the moving image data read from the buffer memory An input data selector for selecting one input and supplying the input to the moving image reproducing circuit in accordance with the execution or release of the mode, and converting the digital moving image data of the color space format output by the moving image reproducing circuit into analog moving image data. And a D / A conversion circuit for converting the data into a digital signal.

With the moving picture reproducing apparatus of the present invention, the load on the CPU is reduced, and reverse reproduction and playback reproduction of moving picture data which do not affect the operation of other applications can be realized. Also, the above-described moving image reproducing apparatus is connected to a high-speed bus such as a PCI bus as a peripheral device, and the compressed moving image data stored in an external storage device such as a DVD is transmitted to a high-performance C / C.
It is also characterized by constructing a computer system capable of handling not only graphics but also multimedia such as moving image data and audio by reading data via a PU and exchanging data with a moving image reproducing apparatus.

[0008]

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 an embodiment of a moving picture reproducing apparatus according to the present invention. In the figure, reference numeral 11 denotes a DMA interface circuit. DMA interface circuit 1
Reference numeral 1 denotes an interface for transferring digital moving image data in the MPEG2 image format transferred via the internal bus 19 to the moving image reproduction LSI 13 at a high speed. Reference numeral 12 denotes an overall control circuit which decodes a command issued from a microprocessor (not shown) and performs various controls described later according to the command. Video playback L
The SI 13 receives digital moving image data compressed by using a method such as MPEG2 via the DMA interface circuit 11, converts the digital moving image data into color space format digital moving image data, and supplies the digital moving image data to the D / A converter 15.
Reference numeral 14 denotes a frame memory for storing image data when the moving image reproducing LSI 13 executes a moving image reproducing process. The D / A converter 15 converts digital moving image data in a color space format transferred from the moving image reproducing LSI 13 into analog moving image data and outputs the analog moving image data to an external device such as a display.

Reference numeral 16 denotes a buffer memory control circuit, and 17 denotes a buffer memory. The buffer memory 17 is used to temporarily store the reproduced moving image data. In the reproduction mode, the stored data is transferred to the buffer memory control circuit 1
6 and is supplied to the moving image reproduction LSI 13 via an input data selector 18 described later. The input data selector 18 receives the moving image data supplied via the DMA interface circuit 11 and the moving image data supplied via the buffer memory control circuit 16 as inputs, and according to the operation mode signal output by the overall control circuit 12. One of them is selected and supplied to the moving image reproduction LSI 13.

Although not shown, the system internal bus 1
9 is connected to an external storage device such as a DVD in which digital moving image data to be reproduced is stored, in addition to the microprocessor described above. In addition, since microprocessors require high-speed processing, Intel U.S.A.
It is assumed that a Pentium processor sold by the company is used. Hereinafter, the microprocessor will be simply referred to as a CPU unless otherwise specified.

FIGS. 2 and 3 are flow charts showing the operation of the embodiment of the present invention shown in FIG. 1, and show a moving image transfer process and a moving image reproducing process, respectively.

Hereinafter, the operation of the embodiment of the present invention shown in FIG. 1 will be described in detail with reference to FIGS. First,
The overall control circuit 12 decodes a command issued by the CPU, and transmits the operation mode information to the buffer memory control circuit 16.
And to the input data selector 18. In the normal reproduction mode, the buffer memory control circuit 16 receives the moving image data supplied via the DMA interface circuit 11 and writes the moving image data into the buffer memory 17. If the writing to the buffer memory 17 exceeds the capacity of the buffer memory 17, the old data is overwritten. Every time moving image data is written to the buffer memory 17, the time information of the last written moving image data is always checked and stored.

When the mode is changed to the reverse reproduction mode, the overall control circuit 12 suspends the transfer of the moving image data by the DMA interface circuit 11 and the input data selector 18.
The data supply to the moving picture reproduction LSI 13 is
An instruction is issued to switch from the output of the interface circuit 11 to the output of the buffer memory control circuit 16. The buffer memory control circuit 16 reads out the moving image data written last, starting from the newest data, and transfers it to the input data selector 18. At this time, if the read moving image data is transferred to the input data selector 18 as it is, the time information added to the moving image data is transferred in a reversed form, and the moving image reproducing circuit 13 is confused. Therefore, using the previously stored "time information of the moving image data finally written in the buffer memory 17", time information in the forward direction is created by the up counter, and the moving image data is passed to the input data selector 18. When the time information is rewritten, the time information is rewritten. At that time, “original time information of the last transferred moving image data” is stored.

When the reverse playback mode is released, the buffer memory control circuit 16 transfers the stored "moving image data finally transferred to the buffer memory 17" in the forward direction again, and the output data becomes The disappearance is transmitted to the overall control circuit 12 and the input data selector 18, and D
The storage of the moving image data output from the MA interface circuit 11 in the buffer memory 17 is restarted. The overall control circuit 12 recognizes the “original time information of the last transferred moving image data” as the reproduction start time information to the moving image reproducing circuit 13 so that the reproduction is started from the moving image data returned by the reverse reproduction. Then, the moving image reproducing operation is restarted. When information indicating that all of the moving image data in the buffer memory 17 has been output from the buffer memory control circuit 16 is issued,
The transfer of moving image data by the MA interface circuit 11 is restarted, and the input data selector 18 is instructed to switch the supply of data to the moving image reproducing circuit 13 from the output of the buffer memory control circuit 16 to the output of the DMA interface circuit 11.

Next, the operation of playback reproduction will be described. The overall control circuit 12 decodes a command issued by the CPU and supplies the operation mode information to the buffer memory control circuit 16 and the input data selector 18. In the normal playback mode, the buffer memory control circuit 16
The moving image data supplied via the A interface circuit 11 is received and written into the buffer memory 17. If the writing to the buffer memory 17 exceeds the capacity of the buffer memory 17, the old data is overwritten. Every time moving image data is written to the buffer memory 17, "time information of moving image data written first" is always checked and stored.

When the mode is changed to the playback mode, the overall control circuit 12 suspends the transfer of the moving image data by the DMA interface circuit 11 and supplies the input data selector 18 with the data supplied to the moving picture reproduction LSI 13 by the D signal.
An instruction is issued to switch from the output of the MA interface circuit 11 to the output of the buffer memory control circuit 16. The buffer memory control circuit 16 reads out the moving image data written first, starting from the oldest data, and transfers it to the input data selector 18. At this time, if the read moving image data is transferred to the input data selector 18 as it is, the time information added to the moving image data is transferred in a changed form, and the moving image reproduction circuit 13 is confused. "Finally, buffer memory 1
The time information in the forward direction is created by the up-counter using the "time information of the moving image data written in 7", and the time information is rewritten when the moving image data is passed to the input data selector 18.

When the change from the playback reproduction mode to the normal reproduction mode is released, the buffer memory control circuit 16
Restarts storing moving image data output from the DMA interface circuit 11 in the jiffer memory 16. When all the data for playback is exhausted, the fact is transmitted to the overall control circuit 12, and the storage of the moving image data output from the DMA interface circuit 11 in the buffer memory 17 is restarted. The overall control circuit 12 causes the moving image reproduction circuit 13 to recognize the original time information of the moving image transferred to the input data selector 18 as reproduction start time information immediately before the start of the playback mode, and restart the reproduction operation. . When the buffer memory control circuit 16 notifies that the playback mode for a certain period of time has ended, the same processing as when the reverse reproduction is canceled is performed.

FIG. 3 shows a personal computer according to the present invention.
FIG. 14 is a diagram illustrating a connection example when applied to a computer system such as a workstation. In the figure, 31 is Pe
A microprocessor (CPU) having performance equal to or higher than that of the ntium processor, and a PC (PC) via a PC peripheral LSI 32 such as a memory (bus) controller.
Connected to I bus 35. Reference numeral 33 denotes a DRAM, which also serves as a main memory and a frame buffer. The above-described moving image reproduction circuit of the present invention, together with a graphics controller, is used as a multimedia LSI 34 as a PCI bus 3
5 is connected. The PCI bus 35 is a time-division multiplexed bus adopting the sustained tri-state system,
A high-speed bus suitable for burst transfer. In order to handle three-dimensional graphics or MPEG2 moving image data handled by the multimedia LSI 34, at least the specifications of the PCI bus or more are required. Reference numeral 36 denotes an input / output control LSI, which serves as a keyboard via these LSIs 36, a DVD,
A file device such as a hard disk is connected.

[0020]

As described above, according to the present invention, the compressed digital moving image data is stored in the DMA interface circuit, the moving image reproducing circuit, the frame memory and the D / A converter which the moving image reproducing apparatus has conventionally. A buffer memory that is sequentially stored, and when an external reverse playback mode or playback playback is instructed, the data stored in the buffer memory is sequentially read out from the newest to the oldest, respectively, and the moving image playback circuit is added to the data. A buffer memory control circuit for adding time information so as not to be aware of reverse playback or playback playback and supplying the time information to the input selector; and a controller for storing the compressed digital video data and the video data read from the buffer memory. Both inputs are made, and one of the inputs is selected according to the execution or release of the above mode. Then, a hardware circuit including an input data selector to be supplied to the moving image reproducing circuit is added, and the playback and the reverse reproduction of the digital moving image are performed by the hardware circuit, thereby reducing the load on the CPU. And the other applications are not adversely affected, thereby improving the system throughput.

The above-mentioned moving picture reproducing apparatus is connected to a high-speed bus such as a PCI bus as a peripheral device, and reads compressed digital moving picture data stored in an external storage device such as a DVD via a high-performance CPU to reproduce the moving picture. By exchanging data with the apparatus, a computer system capable of handling not only graphics but also multimedia such as moving image data and audio can be constructed.

[Brief description of the drawings]

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

FIG. 2 is a flowchart showing a processing procedure of the embodiment.

FIG. 3 is an exemplary diagram showing a connection configuration example of a computer system when the moving image reproduction device shown in FIG. 1 is used as a peripheral device.

FIG. 4 is a block diagram showing an internal configuration of a conventional moving image reproducing apparatus.

FIG. 5 is a flowchart showing an operation in a moving image reproduction process.

FIG. 6 is a flowchart showing a processing procedure by software when a special reproduction mode is issued.

[Explanation of symbols]

11 DMA interface circuit, 12 overall control circuit, 13 moving image reproduction circuit, 14 frame memory, 1
5 D / A converter, 16 buffer memory control circuit, 17 buffer memory, 18 input data selector, 19 local bus, 31 microprocessor
32 ... PC peripheral LSI, 33 ... DRSM, 34 ... Multimedia LSI, 35 ... PCI bus, 36 ... I / O control LSI.

Claims (7)

[Claims] A moving picture reproducing circuit for taking in compressed digital moving picture data and converting it into digital moving picture data in a color space format, and temporarily storing the compressed digital moving picture data taken in the moving picture reproducing circuit. A buffer memory, and a buffer memory control circuit for sequentially reading data stored in the buffer memory in accordance with the mode when externally instructed by a reproduction mode, adding time information according to the mode, and supplying to the input selector. Both the compressed digital moving image data and the moving image data read from the buffer memory are input, and one of the inputs is selected according to execution or cancellation of the mode and supplied to the moving image reproducing circuit. A selector and a color space format output by the moving image reproduction circuit. And a D / A conversion circuit for converting digital moving image data into analog moving image data. 2. When a reverse playback mode is instructed from the outside, stored data is read out from the buffer memory in a new order, and updated time information is added through an input selector so as not to be conscious of reverse playback. 2. The moving picture reproducing apparatus according to claim 1, wherein the data is supplied to a moving picture reproducing circuit. 3. In the normal reproduction mode, incoming moving image data is sequentially written into the buffer memory, and when the mode is changed to the reverse reproduction mode, "last written moving image data"
, The video data is read in the newly written order and transferred to the video playback circuit, and the time information in the forward direction is created using the time information of the "last written video data" When the mode change is released, the moving image playback circuit recognizes the previously stored "original time information of the last transferred moving image data" as the reproduction start information, and outputs the "last transferred image data". 3. The moving picture reproducing apparatus according to claim 2, wherein re-transfer is performed in a forward direction from "moving picture data", and after completion of the transfer, writing of the moving picture data to the buffer memory is restarted. 4. When an instruction for a playback playback mode is issued from outside, stored data is read out from the buffer memory in an old order, and updated time information is added via an input selector so as not to be conscious of playback playback. 2. The moving image reproducing apparatus according to claim 1, wherein the data is supplied to a moving image reproducing circuit. 5. In a normal reproduction mode, incoming moving image data is sequentially written to a buffer memory, and when the mode is changed to a playback reproduction mode, the moving image data is written in an oldest order starting with "first written moving image data". Read the video data in order and transfer it to the video playback circuit.
Using the time information of the "last written video data", create forward time information and rewrite the time information.When the mode change is released, the "time of the original video data 5. The moving picture reproducing apparatus according to claim 4, wherein the moving picture reproducing circuit recognizes the "time information" as the reproduction start information, and restarts the writing of the moving picture data to the buffer memory. 6. A CPU which is a control center of the system, an external storage device in which digital moving image data is compressed and stored, and an input / output which is a command issued by the CPU and a transfer path of the compressed digital moving image data. A bus, a CPU interface circuit that decodes commands issued by the CPU via the input / output bus, and continuously supplies digital moving image data that is subsequently transmitted to the moving image reproducing circuit, and a moving image reproducing circuit. When a playback mode is instructed via a buffer memory and a CPU interface circuit for temporarily storing digital video data to be captured, data stored in the buffer memory is sequentially read in accordance with the mode, and time information is stored in the data. A buffer memory control circuit for supplying an additional signal to an input selector; Both moving image data and moving image data read from the buffer memory are input,
An input data selector for selecting one input and supplying the moving image to the moving image reproducing circuit in accordance with the execution or cancellation of the mode, converting the digital moving image data of the color space format output by the moving image reproducing circuit into analog moving image data. A computer system, comprising: a moving image reproducing device including a D / A conversion circuit for converting and outputting the converted signal to the outside. 7. The input / output bus uses a bus to which addresses and data are transferred in a time-division manner using a common signal line, and first transfers address information using the signal line, and then transfers data continuously. The computer system according to claim 4, wherein the transfer is performed in a selective manner.