Study On Encoding And Transmission Of Embedded Video Based On MPEG-4

With the development of network communication technology and multimedia technology, encoding and transmission of video has been applied in many fields. And the embedded video system was also a hot topic research, recently. The advanced rapid development of embedded system correctly fit this research.The main works of developing digital video system are about video signal's collecting, encoding, transmission, decoding, and displaying. Signal of video is very enormous, so encoding and decoding are the most time-consuming parts in the system. In this paper, we use MPEG-4 to encode video signal. The works are researching of video signal data's format and study of several arithmetic, such as: image compressing(DCT, Quantization, VLC, etc), Motion Estimation(ME) and Motion Compensation(MC). We give some advices about improvements and optimizing. All of the works has been validated under Visual C ++, and we wrote a tidy RTP stack to transfer the encoded video data.As we know, the encode arithmetic is complicated, and encoding must work in real time, so it's difficult to finish the work by traditional software encode design. There are many hardware chip such as IME6400,ADV611, which can encode video data very fast, efficiently, and easily. But hardware is not flexible. Embedded DSP can execute encode arithmetic program easily, because of its great ability in high-speed calculating. And we can upgrade the software conveniently. In this article, we research the embedded network video encoder based on TMS320DM641, which is a high-speed digital multimedia process chip. With consider of DM641's structure and abundant peripheral, the video monitoring system is designed. In allusion to DSP's structure and compile environment, We optimized the MPEG-4 video encode arithmetic, RTP stack, and so on. Our works accelerate the system, meet the requirement of video monitoring system, and make a good base of upgrading for the system.