MP4 muxing libs

Sup /prog/? Have any of you ever worked with:
A. x264
B. libmp4v2
C. GPAC's libraries
D. libavformat
E. Matroska libraries

If you have worked with any of these (but preferably one of the latter four), please let me know. I need to fix my MP4 writing code in Xdot before I can finally release an alpha.

bump for educational reasons

this thread is hilarious

it should serve as an example for all /prog/riders