[MPlayer-users] Convert NTSC to PAL for DVD

[Alexander Roalter]

RC wrote:
> On Sun, 17 Sep 2006 15:13:16 +0200
> Hans du Plooy <koffiejunkielistlurker at koffiejunkie.za.net> wrote:
> 
>> On Sat, 2006-09-09 at 22:33 -0700, RC wrote:
>>> You also need to change the resolution to 720x576 with -vf scale. 
>>> Be sure and set the "interlaced" flag.
>> I'm a bit confused.  I don't find an "interlaced" flag in the man
>> page. Only "ildct" and "ilme" under -lavcopts.  
> 
> The "interlaced" flag TO -vf scale.  Presumably, the video is
> interlaced, and scaling like normal (progressive) video will just
> destroy the picture.
> 
> But yes, you'll want ildct and ilme as well.
> 
>> Is there a way to smooth the judder?
> 
> Like any math problem... 25 just doesn't go into 30.
> 
> Professionally converted videos commonly ghost/motion-blur the fields to
> smooth the motion of the video, but the quality suffers, and I don't
> believe mencoder has any way of doing that, though I can imagine
> modifying something like tinterlaced (and using pp=lb) could make that
> work.
> 
Isn't the professional way to convert NTSC into PAL to do a complete 
inverse telecine?

In the case of film material this means finding of consecutive frames 
the ones which were originally together and fitting them to a new Pal 
frame. As of the 30 NTSC-Frames 24 real frames remain (the 6 left are 
just weaved together from surrounding frames), to get to 25 fps for PAL 
a 4% speedup has to be done.

The original Stream on Film might look like this (A B C D).

Now it is interlaced, say A1, A2 ...

An NTSC stream would look then like this

[A1 A2]  [B1 B2]  [B1 C2]  [C1 D2]  [D1 D2]

with having 30 frames out of 24 orignal. And this is the Data you have 
in your NTSC data.

Now you have to fiddle out and try to re-assemble the proper Data from 
the stream, thus allowing it to get the original corresponding frames out.


Still it's another thing if it is shot natively @30 frames per second 
(e.g. an NTSC video production), which has 30 frames where each of the 
interlaced parts of a picture was shot at a different moment (60 
interlaced frames per second). There you have to use the more 
sophisticated methods which use every trick available to calculate an 
entire image to the exact moment. As this is a crappy job to do, I'm 
stuck with film and watching movies. They don't have this problem. And 
using -speed 0.96 on mplayer lets me play PAL even with 24fps thus 
regaining the original speed and audio pitch :)