ffmpeg是一个大项目，它包含各种音视频标准的codec，还支持各类file format（.avi, .mp4, .mkv and etc）的parsing。所以，很多开源项目都有直接或间接地采用了ffmpeg，-ffmpeg is a big project, which includes all the standard audio and video codec, also support a variety of file format (. avi,. then no time.

详细解析mp4文件的格式，包括头文件，各类压缩模块-describe Mp4 file format in details

基于赫夫曼树的压缩算法 二进制读入文件，对txt有较好压缩效果，而对MP4、pdf等已经被处理过的文件格式效果不不明显。但是是初学者很好的学习资料。(The compression algorithm based on Huffman tree Binary read into the file, TXT has a better compression effect, and MP4, PDF has been processed file format effect is not not