GB2356542A

GB2356542A - Reducing video monitor/cable bandwidth without losing video performance

Info

Publication number: GB2356542A
Application number: GB0023147A
Authority: GB
Inventors: James Arthur Brewer; Sanjay Gupta
Original assignee: International Business Machines Corp
Current assignee: International Business Machines Corp
Priority date: 1999-10-07
Filing date: 2000-09-20
Publication date: 2001-05-23
Also published as: GB0023147D0

Abstract

Reduction of video monitor/cable bandwidth is achieved without losing video performance by the compression (276) of display data before transmission via cable 272 to a display monitor (270). Decompression is performed (274) within the display monitor unit, the data then being displayed on the monitor screen (270).

Description

2356542 METHOD AND APPARATUS FOR REDUCING VIDEO MONITOR/CABLE BANDWIDTH

WITHOUT LOSING VIDEO PERFORMANCE BACXGROUND OF THE INVENTION

1. Technical Field:

The present invention relates generally to an improved data processing system and, in particular, to a method and system of input/output data processing for improving throughput in the transfer of display data to a computer monitor.

2. Description of Related Art:

The power of computer processing continues to increase significantly over time, enabling legacy software applications to be executed more quickly, thereby saving enterprises time and money. However, computer software applications continue to grow more sophisticated over time to take advantage of the newly developed computing power. As users become accustomed to using more complex software, they demand the development of more features within software applications, which in turn generally require computers with increased computational power to be able to execute the newly developed software capabilities within a reasonable amount of time.

This virtuous cycle appears to be able to continue into the distant future.

Some of the most complex software applications currently under development generate sophisticated computer generated images, three-dimensional graphics, and real-time video processing. Humans are able to view large amounts of display data for gaining insight into various scientific problems as well as for entertainment. As a result, more sophisticated computer monitors have been developed that provide better display quality. During the past several years, digital monitors have become viable, affordable displays in the computer industry, which in turn causes more demand for more sophisticated display features in applications.

As software applications create increasing amounts of display data to satiate the desires of computer users, various bottlenecks related to processing and transferring larger amounts of data arise within computer systems used for these applications. in particular, large screen digital monitors require very high data rates, and the increased transfer of data on a display monitor cable causes an additional problem of increasing electromagnetic interference (EMI) radiation.

2 Therefore, it would be advantageous to have a system and method for improving throughput of display data and for reducing EMI radiation related to high data transfer rates to a computer monitor.

It is an object of the present invention to provide a technique which alleviates the above drawbacks.

SUMMARY OF THE INVENTION

According to the present invention we provide a method for transferring data within a data processing system, the method comprising the steps of: generating display data to be transferred to a display monitor; compressing the display data within a video controller in the data processing system;sending the compressed display data to a display monitor; receiving the compressed display data at a display monitor; decompressing the compressed display data; and displaying the decompressed display data on a screen of the display monitor.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:

Figure I is a pictorial representation depicting a data processing system in which the present invention may be implemented in accordance with a preferred embodiment of the present invention; Figure 2A is a block diagram depicting an organization of internal components in a data processing system that may implement the present invention; Figure 2B is a block diagram depicting an organization of internal components in a data processing system that includes the ability to improve throughput of display data in accordance with the present invention; and Figure 3 is a flowchart depicting the steps within a process for improving throughput of display data in accordance with the present invention.

3 DETAILED DESCRIPTION OF THE PREFERRED M4BODIMENT

With reference now to Figure 1, a pictorial representation depicts a data processing system in which the present invention may be implemented in accordance with a preferred embodiment of the present invention. A computer 100 is depicted, which includes a system unit 110, a video display terminal 102, a keyboard 104, storage devices 108, which may include floppy drives and other types of permanent and removable storage media, and mouse 106. Video display terminal 102 connects to system unit 110 via video cable 112. Additional input devices may be included with computer 100.

Computer 100 can be implemented using any suitable computer, for example, an IBM RISC/System 600OAsystem, a product of International Business machines Corporation in Armonk, New York, running the Advanced interactive Executive (AIX) A operating system. Although the depicted representation shows a workstation-type computer, other embodiments of the present invention may be implemented in other types of data processing systems, such as network computers, Web-based television set-top boxes, Internet appliances, etc. Computer 100 also preferably includes a graphical user interface that may be implemented by means of system software residing in computer readable media in operation within computer 100.

Figure 1 is intended as an example and not as an architectural limitation for the present invention.

With reference now to Figure 2A, a block diagram depicts an organization of internal components in a data processing system that may implement the present invention. Data processing system 200 employs a variety of bus structures and protocols. Although the depicted example employs a PCI bus and an ISA bus, other bus architectures may be used.

Processor 202 and L2 cache 204 are connected to PCI bridge 206 via processor bus 208. DRAM memory 210 connects to PCI bridge 206 via memory bus 212. PCI bridge 206 connects to PCI bus 214 that provides interconnections to other PCI buses and media devices. For example, PCI bus 214 connects to PCI riser card 216 that allows the interconnection of other PCI buses, such as interconnect 218 and interconnect 220. PCI bus 214 provides connections for external data streams through network controller 226 and network interconnect 228. Video controller 222 accepts video datastreams through video interconnect 224 and temporarily stores video frames in frame buffer 230 before feeding the video datastream to the rest of the data processing system through PCI bus 214.

4 ISA bridge 232 connects to PCI bridge 206 via interconnect 234. ISA bridge 232 provides interconnection capabilities to a variety of input/output devices. Universal serial bus (USB) 236 provides interconnection capability to common personal electronic devices, such as digital cameras, video disk players, etc., that employ the well known USB standard. Audio controller 238 provides microphone connection 240 and headphone connection 242. Data processing system 200 uses ISA bus 244 to access system boot flash memory 246 in which system boot code may be stored. Real-time clock (RTC) 248 provides timing information to data processing system 200. Super 1/0 interconnect 250 provides interconnection capability to a number of computer peripheral devices and routes the data to and from these devices to data processing system 200 via ISA bus 244.

Serial ports 252-254 provide interconnection capability to devices with serial ports. Parallel port 256 provides interconnection capability to devices that also contain a parallel port. Integrated device electronics (IDE) connection 258 provides an interface to controller electronics that may reside on a disk drive. Compact flash port 260 provides an interface to flash memory cards that are commonly used with small electronic devices and laptop computers and may include such cards as PCMCIA cards. Keyboard connection 262 and mouse connection 264 allow data processing system 200 to accept input data from a user.

With reference now to Figure 2B, a block diagram depicts an organization of internal components in a data processing system that includes the ability to improve throughput of display data in accordance with the present invention. Similar elements in Figure 2A and Figure 2B are labeled similarly. In addition to the connections and components shown in system 200 in Figure 2A, Figure 2B contains monitor 270, connected to video controller 222 via digital video cable 272. The monitor may be one of a variety of digital displays, such as a flat-panel screen, etc. Video compression logic 276 in video controller 222 compresses the display data being sent to monitor 270. Before the display data can be shown on the display screen, decompression logic 274 within monitor 270 decompresses the previously compressed display data. Any variety of compression algorithms may be used by the compression logic, assuming that the decompression logic provides the corresponding reverse process. In general, however, to maintain a high quality picture on the display screen, the system should use a lossless compression scheme. However, the compression scheme could be configurable by the user. If bandwidth on the video cable were a significant problem, the user may choose a lossy compression scheme in order to maintain high data rates. In addition, the compression scheme could be automatically configurable so that the compression logic and the decompression logic perform a compatibility handshake upon power-up.

By compressing the data, fewer bits need to be sent from the video controller to the monitor, thereby reducing the bandwidth on digital video cable 272. Since the amount of data transferred over a connection is reduced for a given amount of display data in a given amount of time, the system also reduces the EMI radiation as a result.

With reference now to Figure 3, a flowchart depicts the steps within a process for improving throughput of display data in accordance with the present invention. The process begins when the video controller receives display data (step 302). The compression logic in the video controller then compresses the digital data (step 304) and sends the compressed is display data to the computer monitor (step 306). The decompression logic in the computer monitor decompresses the display data (step 308), and the computer monitor then displays the data on the video screen (step 310).

The process is then complete with respect to transferring the data from the video controller to the computer monitor using reduced bandwidth.

It is important to note that while the present invention has been described in the context of a fully functioning data processing system, those of ordinary skill in the art will appreciate that the processes of the present invention are capable of being distributed in the form of a computer readable medium of instructions and a variety of forms and that the present invention applies equally regardless of the particular type of signal bearing media actually used to carry out the distribution. Examples of computer readable media include recordable-type media such a floppy disc, a hard disk drive, a RAM, and CD-ROMs and transmission-type media such as digital and analog communications links.

6

Claims

1. A method for transferring data within a data processing system, the method comprising the steps of:

generating display data to be transferred to a display monitor; compressing the display data within a video controller in the data processing system; sending the compressed display data to a display monitor; receiving the compressed display data at a display monitor; decompressing the compressed display data; and displaying the decompressed display data on a screen of the display monitor.

2. A method for transferring data to a display monitor, the method comprising the steps of:

generating display data to be transferred to a display monitor; compressing the display data within a video controller; and sending the compressed display data to a display monitor.

3. A method for receiving data at a display monitor, the method comprising the steps of:

receiving compressed display data at the display monitor; decompressing the display data within the display monitor; and displaying the decompressed display data on a screen of the display monitor.

4. An apparatus for transferring data within a data processing system, the apparatus comprising:

generating means for generating display data to be transferred to a display monitor; compressing means for compressing the display data within a video controller in the data processing system; sending means for sending the compressed display data to a display monitor; receiving means for receiving the compressed display data at a display monitor; decompressing means for decompressing the compressed display data; and displaying means for displaying the decompressed display data at the display monitor.

7

5. An apparatus for transferring data within a data processing system, the apparatus comprising:

generating means for generating display data to be transferred to a display monitor; compressing means for compressing the display data within a video controller; and sending means for sending the compressed display data to a display monitor.

6. An apparatus receiving data at a display monitor, the apparatus comprising:

receiving means for receiving compressed display data at the display monitor; decompressing means for decompressing the display data within the is display monitor; and displaying means for displaying the decompressed display data at the display monitor.

7. A computer program product in a computer-readable medium for use in a data processing system for transferring data to a display monitor, the computer program product comprising:

instructions for generating display data to be transferred to a display monitor; instructions for compressing the display data within a video controller; and instructions for sending the compressed display data to a display monitor.

8. A computer program product in a computer-readable medium for receiving data at a display monitor, the computer program product comprising:

instructions for receiving compressed display data at the display monitor; instructions for decompressing the display data within the display monitor; and instructions for displaying the decompressed display data on a screen of the display monitor.