x264.h
This file defines the "public" interface of x264, so all function you'll need are declared and documented there. Functions
not declared there, shouldn't be called directly by applications.
(For a usage example, the official x264 CLI front-end in
x264.c is probably the best starting point. Alternatively look at
libx264.c in FFmpeg or at the
x264 plug-in of Avidemux)