I want code of c#.net

I am developing a web application Video On Demand in c#.net. I have video conver code in flv format using ffmpeg but I want video convert code in any format. Code to convert flv format gin below

string fname1 = System.Guid.NewGuid().ToString().Replace("-", "") + ".flv";

        string cmd = "-i \"" + Inputpath + "\\" + fnm2  +  "\" \""  + outputpath + "\\" + fname1 + "\"";
      
Please help me to convert any video in any format like 3gp, Mp4, avi etc in c#.net.