A Research Of Portable Multimedia Player

With the development of the society and the progress of technology, the living standards of the people are improving constantly, more and more personal consumptive electronic products which are based on embedded technology come into our life. The MP4 that can play video has been accepted by the peoples, and more and more products appear in the market, but now many of these products are not fully satisfied by the customers, for example, the screen is too small, the picture is not very clear, and it can only play a few video formats; besides, few products have the function of browser. Therefore, to research a multimedia player which have a bigger screen and better performance and support many kinds of video formats, especially have the function of browser have great significance.At first, this thesis introduces the basic principle and standard of video compression, especially take an expatiation of the widely used MPEG-4 standard. A research is done about the principle of the encoding and decoding of the standard, and an analysis is made about the main module of the decoding in details. Secondly, after analyzed the solution of many MP4, a plan of multimedia player is produced from the two sides of hardware construction design and the system function. And then, the X-Hyper255 evaluation board is selected as the prototype developmental and experimental platform, after the tool-chain and JTAG, bootloader program etc are compiled, the embedded cross development condition is established. After that, Linux kernel and file system supplied by the development kit are compiled, then are downloaded to the board, a running environment is setted up for the application development.An excellent opensource software MPlayer is choosed for music and video play next, and is ported to embedded evaluation board successfully after been tested on PC plateform. After an explicit analysis of the play performance is made, the function for decoding and playing MPEG-4 format,s video files in MPlayer program is optimized, and a good result is achieved. Finally, a lightweight browser Dillo is successfully ported to the evaluation board, and the driver of the wireless CF card is compiled , the function of access the net by wireless is implemented.The experimental results indicate that playing multimedia on the evaluation board is successful. This research realized a prototype of multimedia player, which is a solid...