[mythtv-users] real format of .nuv from DVB-T card (mpeg2 with no header?)

[ffrr]

I have often read that the content of the .nuv files that mythtv records 
from my DVB-T card, is already an mpeg2 file.  However, DVDstyler (which 
I am using to make the DVD iso image) does not accept the file, if I 
just rename it to .mpg.  I get the following errors...

"
mmm, this file does not start with a pack, offset: 0
use the desperate_mode switch as the first option -X to search for a 
header in the whole file!
if you want to force the operation. May yield to an endless loop if no 
valid header is found!
warning: couldn't find any valid system header. I'm continuing anyway
mpeg file /mnt/workspace/video/1001_20050727213000_20050727220000.mpg 
can not be demultiplexed (neither System nor Program stream)
"


So, what is a quick and dirty way to make it acceptable? 

I know I can use nuvexport, but it does a conversion of bitrates etc, 
even when you choose DVD output, and works at about 25 frames a second 
on my computer (about real time).  I was hoping to not have to go 
through this lengthy step.

Is there a utility to supply the header that seems to be missing 
(according to the error) without having to reprocess the whole file?