[MPlayer-users] Means of ID_VIDEO_ID=0 ?

[Alessandro Boggiano]

Hi all,
I'm trying to play an avi file on my Kiss Player DP-1000,but  it returns 
"Unknow Fourcc " ".
So,I tried to examine the file with mplayer -identify.

The first thing I discovered is that all my "bad files", has this info 
in common:

ID_VIDEO_ID=0
ID_AUDIO_ID=1

instead of 1 and 1.
What exactly means?
I tried to rencode with the option -ffourcc,but nothing changes!

Any help,please?

TIA
Alex