Ffmpeg is a Swiss-knife for AV developers. It can transcode and trans package AV data in almost any formats. The tools that come with it are very handy too. It’s portability also makes a strong candidate for writing mobile applications. Hardware acceleration support is widespread too.

FFmpeg is just about the best video manipulation tool that has ever been made. Having a command line tool that works across almost every platform is fantastic. Excellent options and there is almost nothing that you can not do with this tool, I use it all the time in conjunction with PHP, Perl, and Python to automate the most hideous repetitive video tasks.

The formats it can use and convert and all the video utilities that can be used.