How To Convert To Pal or NTSC With Dgpulldown
 

Software required
Tmpgenc
Dgpulldown

This method will let you encode avi or mpg files without needing to
change the framerate or audio,all you need to do is encode the movie
clip with the desired resolution such as 352x480/576 or 720x480/576
for dvd compliant files or 480x480/576 for svcd with a program such
as tmpgenc.You will see that when you load a pal avi that you set the
resolution to ntsc(352x480) for example but leave the framerate at
25fps,If it was a ntsc avi then the resolution would be encoded at
352x576 with the framerate left at 23.976.This goes for the other
types of resolutions,just dont change the fps.
 
After the file is encoded then go to tmpgenc/file/mpeg tools/simple de-multiplex
and load the mpg and demux.
 

What you need to do after the file is encoded is open dgpulldown

Then load the m2v that you got from demuxing and browse and open
with dgpulldown and choose the desired fps,if the file was pal-ntsc then the
selection would be 25-> 29.97,for ntsc to pal it would be custom
23.976->25 or 29.97->25 depending what the original fps was.
after the dgpulldown conversion is done then the m2v and mp2 can be
remuxed with tmpgenc/file/mpeg tools/simple multiplex or for dvd
authoring just import the m2v and mp2 directly to the authoring
program

The audio doesnt have to be changed at all with this method in that it
stays the same in time length so theres less chance of the audio going
out of sync.