The Study, Based On The Symbian Platform File Compression And Decompression Technology

This paper is based on smart phone operating system Symbian platform. It has a study about the compression and decompression of file systematically. With the rapid development of the smart phone and Internet, the requirements of data storage and information transmission is becoming more and more higher, especially for smart phone, which has its own characteristics that the CPU and memory are much smaller than the computer, and also facing the problem of battery power consumption. Therefore, more and more attention is focused on the areas of smart phone compression, and it also promotes the research and transplantation about compression algorithm in smart phone.Based on deep understanding of the technology of data compression and mastering the knowledge of Huffman coding, this research uses a modified Huffman coding, Dynamic Huffman coding, which can be used to implement file compression and decompression. With the help of Dynamic Huffman coding, compressing and scanning file can be executed at the same time, avoiding scanning original file twice. And also it avoids the additional memory consumption of preserving the original static Huffman coding table.In this paper, first, it will do requirement and feasibility analysis based on smart phone's specialty, and propose the theoretical basis and building steps for file compression and decompression; then use Carbide C++and Symbian∧3SDK to implement the static Huffman algorithm and dynamic Huffman algorithm of compression and decompression; Finally, through the compression test and contrast with five different data, such as text files, word documents, image files, audio files and video files, it demonstrates the dynamic Huffman coding has been improved nearly30times faster than static Huffman coding. Obviously, dynamic Huffman coding has good applicability and can be used on Symbian platform widely.