Embedded Digital Video Decoding System Design And Implementation

With the advantages of intuition and real-time, the video surveillance systems, which are applied in lots of areas such as expressways, supermarkets, banks, hotels, etc., have become one of the most important means of modern management and surveillance. Nowadays, the video surveillance systems have two categories of the digital-controlled analog video surveillance systems and the digital video surveillance systems. With the development of multimedia, video compressing and encoding, and network communication technologies, the digital video surveillance systems have become the dominant design in the market.The video decoder of the embedded digital video surveillance system was implemented in this paper, based on MPEG-4 and ARM processor using hardware decoding. Main components of the system are EM8550, which was employed as decoding chip, FLASH, SDRAM, as well as Ethernet interface chip. The EM8550 from SIGMA DESIGNS in which an ARM7 processor and the MPEG-1/2/4 decoder are integrated is used as the decoding chip to realize the hardware decoding. The video signal captured by a camera is encoded and compressed, then transmitted via the Ethernet, and decoded into analog video images by the decoder. Finally, these images are displayed on TV set to realize the surveillance. The transplantation of the embedded operation system uClinux used in the decoder system is also discussed in this paper.The decoder system can be widely used in all kinds of digital video surveillance systems. It also can be functionally extended for different video signals, if needed.