实现mpeg4录像文件的回放,支持快进\\快退,多档快速\\慢速,鼠标前后拖拉以改变播放位置(解码显示调用DLL)-achieve documents mpeg4 video playback, support for the Fast Forward \\ soon retreated, and more rapid stall \\ slow, mouse around to change the tedious broadcast location (decoding show calle