JP2000152025A - Interface device for video data - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep the quality of pictures without heavily burdening a system bus or a CPU even in the case of handling of real-time data like moving pictures with respect to an interface device for video data input/output between an external device and a host system. SOLUTION: The interface device for input/output of video data VD1 between the external device and the host system is provided with a video data input interface 10 for input of video data VD1, an external bus interface 20 which has an external bus 5 for connection to the external device and can be operated in the isochronous transfer mode, a system bus interface 30 which has a system bus 7 for connection to the host system, common lines CL1 and CL2 which mutually connect the video data input interface 10, the external bus interface 20, and the system bus interface 30, and a controller 90A which controls flow of data on common lines CL1 and CL2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an interface device for inputting and outputting video data between an external device and a host system.

[0002]

2. Description of the Related Art FIG. 11 shows a video data input / output system 200 to which a conventional interface device 220 is applied.
FIG. 3 is a block diagram showing the configuration of FIG.

As shown in FIG. 11, a video data input / output system 200 includes a personal computer PC as a host system, a VTR 230 and a camcorder (video recording / reproducing device) 240 as external devices, an external bus GB,
And a video data input line VL1.

A personal computer PC has a CPU 2
11, a data processing unit 210 having a memory 212, a bridge circuit 213, a graphics card 214, and the like.
Device 22 having video capture card 221 and external bus interface card 222
0.

[0005] The video capture card 221 has a video data input interface 221a, a system graphics device interface 221b, and a system bus interface 221c. The external bus interface card 222 has a system bus interface 2
22a and an external bus interface 222b.
The video capture card 221 and the external bus interface card 222 are card-shaped devices, and include a system bus S provided in a personal computer PC.
It is plugged into B. Thereby, the data processing unit 2
10, the video capture card 221, and the external bus interface card 222 are connected to each other by the system bus SB. The system bus S
B is, for example, a PCI bus.

The camcorder 240 and the external bus interface 222b are connected by an external bus GB. The external bus GB is, for example, a bus for the IEEE 1394 interface standard.

The VTR 230 outputs video data S21, which is an NTSC signal. The output video data S21 is a video data input line V
It is input to the video capture card 221 via L1. The video data S21 is converted into graphics data S23 in the video capture card 221.
The data is taken into the data processing unit 210 via the system bus SB. The graphics data S23 is stored in the memory 212
Is stored in the IEEE 1
It is converted into a signal S24 of the 394 interface standard. The above signal flow is shown as a path M21 in FIG.

On the other hand, the CPU 211
3. Camcorder 240 via system bus SB, external bus interface card 222, and external bus GB
To the control signal S22. If the conditions for receiving data are satisfied in the camcorder 240, the memory 21
The video data S22 stored in the bridge circuit 2
13. Camcorder 240 via system bus SB, external bus interface card 222, and external bus GB
To be recorded there.

In this way, the video data S21 output from the VTR 230 is sent to the camcorder 240,
Thereby, the video data S21 can be reproduced or dubbed.

[0010]

However, according to the conventional video data input / output system 200 described above, the video capture card 221 and the external bus interface card 222 are each connected to the system bus SB, and the video data S21 is Before being sent to the camcorder 240, the system bus SB is routed through paths M21 and M23.
It is necessary to go through a total of two times as shown in. The control signal S22 also needs to pass through the system bus SB. As a result, when dealing with real-time data such as a moving image, the amount of data processed per unit time increases, and a heavy load is placed on the system bus SB and the CPU 211. As a result, the image quality is degraded and the image is dropped due to an insufficient transfer bandwidth of the system bus SB and an insufficient processing capability of the CPU 211. In addition, when audio is input and output together with an image, a synchronization shift may occur between the image and the audio.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and is directed to a case where real-time data such as a moving image is handled in an interface device for inputting and outputting video data between an external device and a host system. However, an object of the present invention is to provide a video data interface device capable of maintaining image quality without imposing a large burden on a system bus and a CPU.

[0012]

According to the first aspect of the present invention, there is provided an apparatus comprising:
An interface device for inputting / outputting video data between the external device 3 and the host system PC1, a video data input interface 10 for inputting video data, and an external bus for connecting to the external device 3. 5, an external bus interface 20 operable in the isochronous transfer mode, a system bus interface 30 having a system bus 7 for connecting to the host system PC1, and the video data input interface 1.
0, common lines CL1 and CL2 connecting the external bus interface 20 and the system bus interface 30 to each other, and a controller 90 for controlling a data flow in the common lines CL1 and CL2.

An apparatus according to a second aspect of the present invention includes a system graphics device interface 40 for outputting the video data to the host system PC1 via a system graphics device 6a.

According to the third aspect of the present invention, there is provided a sound data input interface for inputting sound data.
And the sound data to the system sound device 6.
b, and a sound data output interface 60 for outputting to the host system PC1 through the interface b.

The device according to claim 4 is characterized in that the common line C
L1 and CL2 include the video data input interface 10 or the sound data input interface 50, respectively.
And a restoring unit 80 for restoring data and outputting the data to the system graphics device interface 40 or the sound data output interface 60.

In the apparatus according to the fifth aspect, the controller 90 is provided with a buffer memory 90C2 for storing data flowing through the common lines CL1 and CL2, and a switching means 90C1 for switching data flow. 90 is the common line CL1,
The common lines CL1 and CL2 are arranged so that data in CL2 flows through the controller 90.

In the apparatus according to the sixth aspect, the external bus 5
Using an IEEE 1394 serial bus.

The controller 90 controls operations of the video data input interface 10, the external bus interface 20, the system bus interface 30, and the like. In particular, the operation state of the external bus interface 20 is constantly monitored, and fine control is performed.

Further, the controller 90 converts the input video data into the video data input interface 10,
The data is transferred to the external bus via the common line CL1 and the external bus interface 20. As a result, video data is converted from, for example, an NTSC signal to, for example, IEEE
The signal is converted into a signal of the 1394 interface standard and sent to the external device 3.

As described above, since the video data can be directly transferred to the external device 3, the video data is once sent to the data processing unit via the system bus to perform the signal conversion, as in the related art. There is no need to perform a complicated operation such as sending to the camcorder via the system bus again. Therefore, the burden on the system bus 7 and the CPU is reduced. For this reason, even when real-time data such as a moving image is handled, it is possible to maintain the image quality without deteriorating the image quality or dropping the frames of the image.

[0021]

FIG. 1 shows a video data input / output system VS1 to which an interface device 1 according to the present invention is applied.
FIG. 3 is a diagram showing the configuration of FIG.

As shown in FIG. 1, a video data input / output system VS1 comprises a personal computer PC1, a VT
R2, a camcorder 3, a data input line 4, and an external bus 5.

The personal computer PC1 comprises an interface device 1 and a data processing unit 6. The data processing unit 6 includes a CPU, memories such as a RAM and a ROM, a hard disk, a graphics device 6a, and various other peripheral devices.

The interface device 1 and the data processing unit 6 are connected by a system bus 7 inside the personal computer PC1.
And the graphics device 6a are connected by a line L1. Also, the interface device 1 and the VTR
2 is connected by an input line 4, and the interface device 1 and the camcorder 3 are connected by an external bus 5.

The system bus 7 is, for example, a PCI bus. The external bus 5 is a bus of the IEEE 1394 interface standard. The VTR 2 outputs NTSC video data VD 1. Video data VG1 is output from the camcorder 3.

The video data input / output system VS1 has a function of transferring the video data VD1 to the camcorder 3 for reproduction or dubbing, a function of taking the video data VD1 into the data processing unit 6 and performing predetermined processing, and a function of the video data VG1. Has a function of taking in the data processing unit 6 and performing predetermined processing.

A control signal CD for monitoring the state of the camcorder 3 is provided between the data processing unit 6 and the camcorder 3.
Flows through the system bus 7, the interface device 1, and the external bus 5 in two directions in real time.

The same processing as the video data VD1 and VG1 can be performed on the sound data output from the VTR 2 or the camcorder 3, respectively.

Next, a specific configuration and operation of the interface device 1 will be described. [First Embodiment] FIG. 2 is a block diagram showing the configuration of an interface device 1A according to a first embodiment.

As shown in FIG. 2, the interface device 1
A is a video data input interface 10, an external bus interface 20, a system bus interface 3.
0, a controller section 90A, an internal bus CL1, a control line CL2, an external bus 5, and a system bus 7.

The video data input interface 10
It has an analog video decoder. The video decoder converts the input analog NTSC video data VD1 into a digital signal and converts the data into RGB or YUV data format. Therefore, the NTSC video data VD1 input to the video data input interface 10 is converted into a digital signal that is easy to handle for transfer to other interfaces. The external bus interface 20 is an IEEE having an isochronous transfer (Isochronous transfer) function.
Operation according to the E1394 standard is possible. The external bus interface 20 is provided with an external bus 5 of the same standard. As a result, it is possible to preferentially transfer data important to be transferred at a certain timing, for example, data such as audio and moving images.

The system bus interface 30 is connected to the system bus 7. The system bus 7 is a route for accessing the peripheral system from the parent system, and includes a PCI bus, a PC card interface, and an ISA.
Buses and various CPU buses.

The video data input interface 10, the external bus interface 20, and the system bus interface 30 are interconnected by an internal bus CL1 and a control line CL2. Data flows from the external bus interface 20 and the system bus interface 30 to the internal bus CL1, and a control signal from the controller 90A flows to the control line CL2.

The controller unit 90A includes a video data input interface 10, an external bus interface 20,
And controls the operation of the system bus interface 30. In particular, the operation state of the external bus interface 20 is constantly monitored, and fine control is performed.

The controller 90A can execute the following control operations MD1 to MD3.

The control operation MD1 includes the video data VD1
To the video data input interface 10, the internal bus C
This is a control operation for transferring data to the external bus 5 via the L1 and the external bus interface 20. In the control operation MD2, the video data VD1 is transferred to the system bus 7 via the video data input interface 10, the internal bus CL1, and the system bus interface 30. In the control operation MD3, the control signal CD is bidirectionally transferred between the external bus 5 and the system bus 7.

The control operation MD1 is performed when the video data VD1 is reproduced or dubbed by the camcorder 3. The video data VD1 is controlled by the control operation MD1.
Is converted from a signal of the NTSC system into a signal of the IEEE 1394 interface standard, and sent to the camcorder 3. The control operation MD3 is executed, for example, when the control operation MD1 is executed so that the data processing unit 6 monitors the camcorder 3 in real time by the control signal CD.

By the control operation MD1, the video data V
Since D1 can be directly transferred to the camcorder 3, the video data VD1 is once sent to the data processing section 6 via the system bus 7 as in the prior art, and after signal conversion there, it is again performed. There is no need to perform a complicated operation such as sending to the camcorder 3 via the. Therefore, the load on the CPU of the system bus 7 and the data processing unit 6 is reduced. For this reason, even when real-time data such as a moving image is handled, the image quality can be maintained without lowering the image quality or dropping the frames of the image.

The control operation MD2 includes the video data VD1
Is executed as graphics data in the data processing unit 6 (video capture).

When data transfer is performed in each of these control operations MD1 to MD3, the data flow is performed using the internal memories provided in the video data input interface 10, the external bus interface 20, and the system bus interface 30. And processing such as buffering are performed. [Second Embodiment] FIG. 3 is a block diagram showing a configuration of an interface device 1B according to a second embodiment.

As shown in FIG. 3, the interface device 1
B has a system graphics device interface 40 for outputting video data VD2 in addition to the configuration of the interface device 1A of the first embodiment, and has a controller unit 90B instead of the controller unit 90A in the interface device 1A. . Other configurations are the same as those of the interface device 1A.

The system graphics device interface 40 is connected to the system graphics device 6a of the data processing unit 6. The system graphics device 6a is hardware for speeding up graphics processing. In a personal computer, it is called a graphics accelerator. For example, a VESA future connector is used for the system graphics device 6a.

The controller 90B can execute a control operation MD4 and a control operation MD5 in addition to the control functions of the controller 90A.

The control operation MD4 includes the video data VD1
To the video data input interface 10, the internal bus C
L1 and a control operation of transferring to the system graphics device 6a via the system graphics device interface 40. The control operation MD5 is a control operation of transferring the video data VG1 obtained from the camcorder 3 to the system graphics device 6a via the external bus interface 20, the internal bus CL1, and the system graphics device interface 40.

The system graphics device 6a can perform various processes such as video capture, video overlay, texture mapping, and α blending on the transferred video data VD1 or VG1. Unlike the first embodiment, the video data VD1 or VG1 is video-captured without passing through the system bus 7, so that the load on the system bus 7 is further reduced. [Third Embodiment] FIG. 4 is a block diagram showing a configuration of an interface device 1C according to a third embodiment.

As shown in FIG. 4, the interface device 1
C is a controller 90C instead of the controller 90B in the interface device 1B of the second embodiment.
Having. Other configurations are the same as those of the interface device 1B.

The controller unit 90C has an internal bus CL1.
And is provided in the middle of the control line CL2. The controller unit 90C has a bus switch 90C1 and a buffer memory 90C2, and has the same control function as the controller unit 90B. The bus switch 90C1 switches between the control operations MD1 to MD5. Buffer memory 9
0C2 is used to control data flow and buffering via the internal bus CL1 and the control line CL2 when each transfer is performed by the control operations MD1 to MD5. In the first or second embodiment, processing such as data flow and buffering is performed using the internal memories of the video data input interface 10, the external bus interface 20, and the system bus interface 30. In the embodiment, the buffer memory 90C2 handles most of its functions. Therefore, the load on the internal memories of the respective interface units is reduced, and their capacity can be reduced. Further, since the memory utilization efficiency is improved as a whole, the cost can be reduced accordingly. [Fourth Embodiment] FIG. 5 is a block diagram showing the configuration of an interface device 1D according to a fourth embodiment.

As shown in FIG. 5, the interface device 1
D has a sound input interface 50 for inputting sound data SD1 in addition to the configuration of the interface device 1B of the second embodiment, and has a controller unit 90D instead of the controller unit 90B in the interface device 1B. Other configurations are the same as those of the interface device 1B.

The sound input interface 50 is provided so as to be in parallel with the video data input interface 10 and has the sound data SD output from the VTR 2.
Enter 1.

The controller 90D can execute a control operation MD6 and a control operation MD7 in addition to the control functions of the controller 90B. The control operation MD6 is a control operation for transferring the sound data SD1 to the external bus 5 via the sound input interface 50, the common bus CL1, and the external bus interface 20. In the control operation MD7, the sound data SD1
To the sound input interface 50 and the internal bus CL.
1, and transfer to the system bus 7 via the system bus interface 30.

The control operation MD6 corresponds to the sound data SD1.
Is reproduced or dubbed in the camcorder 3. The control operation MD7 is performed when the sound data SD1 is taken into the data processing unit 6 and predetermined data processing is performed.

When the video data VD1 is transferred together with the sound data SD1, the sound data SD1 and the video data VD1 are transferred to the external bus 5 or the system bus 7 in synchronization with each other. [Fifth Embodiment] FIG. 6 shows an interface device 1E according to a fifth embodiment.
FIG. 3 is a block diagram showing the configuration of FIG.

As shown in FIG. 6, the interface device 1
E has a sound output interface 60 for outputting sound data SD2 in addition to the configuration of the interface device 1D of the fourth embodiment, and has a controller unit 90E instead of the controller unit 90D in the interface device 1D. Other configurations are the same as those of the interface device 1D.

The sound output interface 60 is connected to the system sound device 6b in the data processing section 6.

The controller 90E has a control function of the control operations MD8 to MD10 in addition to the control function of the controller 90D.

The control operation MD8 includes the sound data SD1
To the sound input interface 50 and the internal bus CL.
1, and a control operation for transferring the data to the system sound device 6b via the sound output interface 60. The control operation MD9 transmits the sound data SS1 sent from the system bus 7 to the system bus interface 3
0, an internal bus CL1, and a control operation for transferring the sound to the system sound device 6b via the sound output interface 60. The control operation MD10 transmits the sound data SG1 sent from the external bus 5 to the system sound device 6b via the external bus interface 20, the internal bus CL1, and the sound output interface 60.
This is a control operation for transferring the data to.

The control operations MD8, MD9 and MD10 are executed when the sound data SD1, SS1 and SG1 are taken into the data processing section 6 and predetermined data processing is performed. [Sixth Embodiment] FIG. 7 is a block diagram showing a configuration of an interface device 1F according to a sixth embodiment.

As shown in FIG. 6, the interface device 1
F has a data compressing section 70 and a data restoring section 80 in addition to the configuration of the interface apparatus 1E of the fifth embodiment, and the controller section 9 in the interface apparatus 1E.
A controller unit 90F is provided in place of 0E. Other configurations are the same as those of the interface device 1E.

The data compression unit 70 is provided in the middle of the internal bus CL1 and the control line CL2, and is connected to the video data input interface 10, the sound input interface 50, and the external bus interface 2 by the internal bus CL1.
0, the system bus interface 30, and the data restoring unit 80. The data compressing section 70 converts the video data VD1 and VG transmitted via the internal bus CL1.
1, VS1 and sound data SD1, SG1, SS1
Perform compression processing on the data.

The data restoring unit 80 is provided in the middle of the internal bus CL1 and the control line CL2, and is connected to the system graphics device interface 40, the sound output interface 60, the external bus interface 20, the system bus interface 30, by the internal bus CL1. And a data compression unit 70. Data restoration unit 8
0 indicates compressed video data and compressed sound data transmitted from the system bus 7 via the system bus interface 30 and the internal bus CL1, and 0 indicates the external bus 5 via the external bus interface 20 and the internal bus CL1. A decompression process is performed on the transmitted compressed video data and compressed sound data.
The data subjected to the restoration processing is output to the system graphics device interface 40 or the sound output interface 60.

The data compression section 70 or the data decompression section 80 does not perform compression processing or decompression processing.
It is also controlled so that data flows through. These controls are performed by the controller unit 90F. The data compression unit 70 and the data decompression unit 80 are, for example, MPEG2
And DV codecs. Seventh Embodiment FIG. 8 is a block diagram showing the configuration of an interface device 1G according to a seventh embodiment, and FIG. 9 is a diagram showing the details of the configuration of the interface device 1G.

As shown in FIG. 8, the interface device 1
G is a controller unit 90G instead of the controller unit 90F in the interface device 1F of the sixth embodiment.
Having. The controller unit 90G is provided in the middle of the internal bus CL1 and the control line CL2. Other configurations are the same as those of the interface device 1F.

As shown in FIG. 9, the video data input interface 10 has an NTSC decoder 11. The external bus interface 20 has an IEEE 1394 link layer controller 21 and a physical layer controller 22.

The system bus interface 30 is a PC
It has an I interface controller 31. The system graphics device interface 40 has a data transmission controller 41. Sound input interface 5
0 has an AD converter 51, a data format converter 52, and a sound buffer 53. The sounded output interface 60 has a DA converter 61, a data transmission controller 62, and a sound buffer 63. The data compression unit 70 includes a DV video encoder 71,
It has a DV sound encoder 72, a DV system encoder 73, and a buffer memory 74. The data restoration section 80 has an MPEG2 video decoder 81, an AC-3 decoder 82, an MPEG2 system decoder 83, and a buffer memory 84. The controller unit 90G includes a bus switch 90G1, a buffer memory 90G2, a memory controller unit 90G3, a bus interface arbitrator 9
0G4, MPU90G5, and firmware 90G6
Having.

In the present embodiment, since data compression processing is performed, and the controller unit 90G has the buffer memory 90G2, the memory capacity of each interface unit can be reduced.

Next, another example of use of the interface device 1 will be described.

FIG. 10 is a diagram showing a configuration of a video data input / output system VS2 to which the interface device 1H is applied.

As shown in FIG. 10, the video data input / output system VS2 comprises a personal computer PC2, a television receiver TV, a set-top box SB, an external bus 5, and a data line L2.

The personal computer PC2 comprises an interface device 1H and a data processing unit 6.
The interface device 1H and the data processing unit 6 are connected by a system bus 7 inside the personal computer PC1, and the interface device 1H and the graphics device 6a are connected by a line L1. The interface device 1 and the set-top box SB are connected by an external bus 5, and the television receiver TV and the set-top box SB are connected by a data line L2.

The interface device 1H has substantially the same configuration as the interface device 1 in the video data input / output system VS1, except that a digital video decoder is provided in the video input interface.

From the graphics device 6a, digital video data VDD created in the data processing section 6 is sent to the interface device 1H via the line L1. The video data VDD is converted into a signal conforming to the IEEE 1394 interface standard in the interface device 1H and sent to the set box SB via the external bus 5. Video data VDD of the IEEE 1394 interface standard is set to N in the set box SB.
The video data is converted into the video data VDN of the TSC system and output to the television receiver TV via the data line L2.

In the above embodiment, the external bus 5
In the case of the IEEE 1394 standard, real-time data such as video data VD1 and sound data SD1 can use a maximum of 7/8 of the transfer band, and the rest is asynchronous transfer of control data CD and the like. It can be used for Therefore, real-time video data VD1, sound data SD1, etc., and control data C
And D can be simultaneously transferred in the single internal bus CL1.

According to the above embodiment, the video data V
The process of converting D1 into a signal conforming to the IEEE 1394 interface standard is performed by the operation of the video data input interface 10 and the external bus interface 20 under the control of the controller units 90A to 90G. That is, it is not necessary to send the video data VD1 to the data processing unit 6 via the system bus 7 as in the related art, in order to convert the signal into the signal of the IEEE 1394 interface standard. When the video data VD1 is transferred to the camcorder 3, the signal passing through the system bus 7 is only the control signal CD, so that the load on the system bus 7 is reduced. Further, the load on the CPU in the data processing unit 6 is reduced. For this reason, even when real-time data such as a moving image is handled, a high-quality image can be obtained in the camcorder 3.

According to the above-described embodiment, the video data input interface 10, the external bus interface 20,
And the system bus interface 30 includes an internal bus CL1 and a control line CL2 in the interface device 1.
And the mounting form is integrated. Therefore, the video data input interface 10,
The cost can be reduced as compared with the case where the external bus interface 20 and the system bus interface 30 are individually connected to the system bus 7.

In the above embodiment, an example has been described in which the external device is the camcorder 3 or the set-top box SB. However, another external device, for example, another personal computer may be used. Also, the video data VD1 is set to NT
Although the SC system is used, the PAL system may be used.

In the above-described embodiment, the personal computers PC1 and PC2 serve as the server and the camcorder 3
Alternatively, the set-top box SB can be used as a client-side system as a client side.

In the embodiment described above, the flow of data via the internal bus is controlled by the controller units 90A to 90G, but may be controlled by the data processing unit 6. In addition, the configuration, shape, arrangement, circuit, processing content, order, and the like of each unit or the entirety of the interface devices 1A to 1G and the video data input / output systems VS1 and VS2 can be appropriately changed in accordance with the gist of the present invention.

[0078]

According to the present invention, in an interface device for inputting / outputting video data between an external device and a host system, even when real-time data such as a moving image is handled, a system bus and a CPU can be used. The image quality can be maintained without imposing a great burden.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a video data input / output system to which an interface device according to the present invention is applied.

FIG. 2 is a block diagram illustrating a configuration of an interface device according to the first embodiment.

FIG. 3 is a block diagram illustrating a configuration of an interface device according to a second embodiment.

FIG. 4 is a block diagram illustrating a configuration of an interface device according to a third embodiment.

FIG. 5 is a block diagram illustrating a configuration of an interface device according to a fourth embodiment.

FIG. 6 is a block diagram illustrating a configuration of an interface device according to a fifth embodiment.

FIG. 7 is a block diagram illustrating a configuration of an interface device according to a sixth embodiment.

FIG. 8 is a block diagram illustrating a configuration of an interface device according to a seventh embodiment.

FIG. 9 is a diagram illustrating details of a configuration of an interface device according to a seventh embodiment;

FIG. 10 is a diagram showing a configuration of another video data input / output system to which the interface device according to the present invention is applied.

FIG. 11 is a block diagram showing a configuration of a video data input / output system to which a conventional interface device is applied.

[Explanation of symbols]

Reference Signs List 1 interface device 3 camcorder (external device) 5 external bus 6 data processing unit 6a system graphics device 6b system sound device 7 system bus 10 video data input interface 20 external bus interface 30 system bus interface 40 system graphics device interface 60 sound output interface ( Sound data output interface) 6b System sound device 70 Data compression section (compression section) 80 Data restoration section (restoration section) 90 Controller section (controller) 90C1, 90G1 Bus switch (switching means) 90C2, 90G2 Buffer memory PC1, PC2 Personal computer (Host system) VD1 Video data SD1 Sound data CL1 Internal bus (Common line) CL2 Control line (Common line) SB Set-top box (External device)

Continuation of the front page (72) Inventor Tohru Uewada 4-1-1, Kamidadanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Inside Fujitsu Limited (72) Inventor Eiji Hasegawa 4-1-1, Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa No. Fujitsu Limited F-term (reference) 5C056 FA02 GA20 HA01 HA04 5K033 AA03 BA14 BA15 CB06 DA01 DA13 DA15 DB04 DB17 DB21

Claims (6)

[Claims] An interface device for inputting and outputting video data between an external device and a host system, comprising: a video data input interface for inputting video data; and an external device for connecting to the external device. An external bus interface having a bus and operable in an isochronous transfer mode; a system bus interface having a system bus for connecting to the host system; the video data input interface, the external bus interface; and the system bus A video data interface device, comprising: a common line that connects interfaces to each other; and a controller that controls data flow in the common line. 2. The video data interface device according to claim 1, further comprising a system graphics device interface for outputting said video data to said host system via a system graphics device. 3. A sound data input interface for inputting sound data, and a sound data output interface for outputting the sound data to the host system via a system sound device. Video data interface device. 4. A compression unit for compressing data obtained from the video data input interface or the sound data input interface, wherein the common line includes:
4. A restoration unit for restoring data and outputting the data to the video data output interface or the sound data output interface.
An interface device for video data as described. 5. The controller is provided with a buffer memory for storing data flowing through the common line, and switching means for switching the flow of data. The controller is adapted to transmit data on the common line via the controller. 5. The video data interface device according to claim 1, wherein the video data interface device is arranged so as to flow through the common line. 6. The video data interface device according to claim 1, wherein an IEEE 1394 serial bus is used as said external bus.