I tried to repeat this tutorial, loading my own MP4 file. After clicking "open" in the movie clip editor and picking the file, it didn't seem to load and here's what I got in the terminal:
not an anim: /path/to/file.mp4
At the same time, file says it's ISO Media, MP4 Base Media v1 [IS0 14496-12:2003]. Is there any preprocessing I should do before I import it to Blender? How could I do it with mencoder or ffmpeg?