Fujitsu Laboratories Ltd. Fujitsu Limited

Tokyo, February 8, 2002 - Fujitsu Laboratories Ltd. and Fujitsu Limited today announced the development of an MPEG4 video codec circuit that runs on just 9 milliwatts. When incorporated into a larger system LSI design, the new circuit will permit mobile devices, such as cellphones, PDAs, and digital cameras, as well as portable terrestrial digital broadcast transmitters, to handle MPEG4 video with minimal power requirements. Fujitsu has also incorporated this codec into a multimedia LSI design it has developed for mobile devices, which is scheduled to be released later this year.

The new circuit was unveiled this month at the ISSCC2002 (2002 IEEE International Solid-State Circuits Conference).

Background
With the growing use of digital equipment and the emergence of digital broadcasting, the visual component of the MPEG4 multimedia encoding standard, which compresses video data, is being used more extensively. The high compression ratio of MPEG4 enables it to be transmitted over relatively low-bandwidth connections, and due to its superior resilience to transmission errors, MPEG4 is expected to be the video compression format of choice for mobile applications.

Since previous MPEG4 codec circuits were designed chiefly for use in 3G cellphones, they do not offer the high-quality compression needed for digital cameras and other such equipment. There has been, therefore, a pressing need for low-power MPEG4 codec technology suitable for a wide range of applications.

About the Technology
The new codec circuit compresses a video signal into an MPEG4-encoded stream, and decompresses an MPEG4-encoded stream to reconstitute the digital video. Figure 1 shows a prototype chip incorporating this circuit, along with its major specifications.

Results from the test chip show that the codec circuit can operate on as little as 9 mW, the lowest power requirements yet achieved in the industry, when used to simultaneously compress and decompress the QCIF-sized (176 x 144 pixel), 15 frames-per-second signal needed for a wireless videophone. This design can both generate and play back higher-quality video streams up to CIF size (352 x 288 pixel) at 30 fps, or 2 Mbits per second (see Figure 2).

Noteworthy features of the new circuit:
1. Motion-estimation circuit
The circuit includes newly developed motion-estimation logic to adaptively pick out moving vectors in a scene. Compared to the existing fixed-search technique, this method entails only about one-twentieth the computational load for detecting motion, which is the most intensive aspect of video compression. This feature enables the circuit to achieve better performance for less power.

2. Autonomous clock gating control
On the basis of image size and frame rate, internally the circuit dynamically determines the minimum circuit block requirements, supplying the clock at that minimum rate for further power optimization.

Figure 1: Prototype Chip with MPEG4 Codec Circuit

Compression Format MPEG-4 Simple Profile@L3 Image Size Max. 352x288 pixels Frame Rate Max. 30 fps Bit Rate Max. 2M bps Technology 0.18µm CMOS Supplied Voltage 1.5V (internal) 3.3V (I/O) Clock Frequency 13.5MHz (codec) 54MHz (memory interface) Gate Count 700k gates (total) 400k gates (codec) Die Size 5.3mm2

Compression Performance

[click to enlarge]
Figure 2: Performance Range for New Codec Circuit

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About Fujitsu Laboratories Ltd.
Founded in 1968 as a wholly owned subsidiary of Fujitsu Limited, Fujitsu Laboratories Limited is one of the premier research centers in the world. With a global network of laboratories in Japan, China, the United States and Europe, the organization conducts a wide range of basic and applied research in the areas of Multimedia, Personal Systems, Networks, Peripherals, Advanced Materials and Electronic Devices. Internet: http://www.labs.fujitsu.com/

About Fujitsu
Fujitsu is a leading provider of Internet-focused information technology solutions for the global marketplace. Its pace-setting technologies, best-in-class computing and telecommunications platforms, and worldwide corps of systems and services experts make it uniquely positioned to unleash the infinite possibilities of the Internet to help its customers succeed. Headquartered in Tokyo, Fujitsu Limited (TSE:6702) reported consolidated revenues of 5.48 trillion yen for the fiscal year ended March 31, 2001. Internet: http://www.fujitsu.com/

[Press Contacts] Minoru Sekiguchi, Nancy Ikehara Fujitsu Limited, Public Relations Tel: +81-3-3215-5259 (Tokyo) Fax: +81-3-3216-9365 Press Inquiries

[Technical Contact] Fujitsu Laboratories Advanced System LSI Research Dept. Tel: +81-44-754-2535 (Kawasaki) E-mail: otobe@jp.fujitsu.com

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