A Highly Integrated Mpeg-4 Asic for Sdcam Application

The advances in flash memory technology have substantially pushed the capacity limit to the Gigabyte region in recent years. Today, flash-memory has become a viable recording media for the Solid-State Digital Camcorder (SDCam) application. MPEG-4 video coding offers remarkable compression efficiency that makes it an attractive candidate for such bandwidth critical applications. MPEG-4 technology enables entertainmentquality multimedia data to be stored at about 550 kbits/sec, which allows a 128 MB flash memory device to record nearly 30-minute video footage. This paper describes a dedicated System-on-Chip (SoC) ASIC device for the flash-memory based camcorder application. This device incorporates the Advanced Coding Efficiency visual tools and the AAC stereo audio coding to accomplish highquality A/V coding. In order to lower system cost and to simplify system design, the device has also incorporated key peripheral interfaces for a camcorder, such as sensor, LCD, host controller, SDRAM, Zoom/AF control, and flash. The device also includes a JPEG engine to add the digital still camera capability to the camcorder. It can handle still pictures up to four Megapixel. To meet the high-speed computational requirements for motion estimation, the ASIC incorporates a set of four array processors with 8×8 elements each. The device can deliver real-time encoding for CIF size sequences at 30 frames per second with selectable bit rates from 64 kbps to 2 Mbps.