How to write native .mp4 files to disk?

[g1h2]

I compiled dump filter and add it after the compressor this way:

+---------+ RGB24+---------+ *F(24bits) +-----+
|Cam input| ---->|Encoder| ----------> |DUMP|
+---------+ +---------+ +-----+

F (Fromat)= MP4/MP4v2, divx, etc.

the dump isin't playable anywhere. It doesn't seems to be even a .mp4v file (video part of a .mp4).

Any suggestions (Tried mp4ip's mp4creator but it doesn't recognize the dump file) on how to have something usable out of this dump?

p.s.: mp3 dump do work great thought.