I am c++/C# expert.
And I know rich experience in PHP and js.
I am familiar to following as:
Network communication(TCP/IP, UDP, RTSP/RTP, HTTP, SMTP...)
Database(MySQL, Sqlite, Access, Excel, Oracle, MSSQL...)
Computer security & Encrypt/Decrypt(DES...)
Project reversing, Multi-processing, Multi-threading
Image processing(OpenCV, OpenGL...)
Video codec processing(H264/265, ffmpeg, Mpeg4, YUY2...)
Audio codec processing(Mp3, Ogg...)