I am researching on video processing. I should use open source video encoding softwares to understand the internal structure of a video file. The problem of open source software is that you encounter with hundreds of functions and headers, containing thousands of lines of codes. For finding what is really happen when you enter a parameter and run the program, you need to know how these functions are related to each other and what they pass and receive among themselves. I am looking for a case tools or any other software, to visualize the interrelation of functions in C language. Can you help me to find a solution for my problem?