[MPlayer-users] Re: Re: Telecine output - needed for NTSC DVD encoding

[Bruno]

>
> Tobias Diedrich wrote:
>
> It is not enabled unless you explicitly insert one of the ivtc filters.
> I guess what you want is to use "-vf softpulldown" and "-lavcopts ildct".
>

Been there, done that, doesn't work.
I've done some hard-telecine and soft-telecine analisys over the original 
and Mencoded streams.
Used Windows tools.

Mencoded (Soft Telecine test through DVD2AVI):

7 0 0 2
7 0 9 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
7 0 5B 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
7 0 AB 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
7 0 F5 2 2 2 2 2 2

Original (Soft Telecine test through DVD2AVI):

7 0 0 0 1 2 3 0 1 2 3 0 1 2 3
7 0 EF 0 1 2 3 0 1 2 3 0 1 2 3
7 0 1D1 0 1 2 3 0 1 2 3 0 1 2 3
7 0 2B0 0 1 2 3 0 1 2 3 0 1 2 3
7 0 38D 0 1 2 3 0 1 2 3 0 1 2 3

Soft telecine pattern in DVD2AVI is 0123 or 2301 where:

0 -> BFF (bottom field first)
1 -> BFF + RFF (bff + repeat first field)
2 -> TFF (top field first)
3 -> TFF + RFF (tff + repeat first field)

As for hard-telecined tests I used Avisynth + Decomb with this script:

Loadplugin("D:\kvcd\progs\dvd2avi\MPEG2Dec3.dll") 		
Loadplugin("D:\kvcd\progs\dvd2avi\Decomb.dll")

function FOrder(clip c) {
fo= GetParity(c)? 1:0
return fo
}

#mpeg2source("D:\kvcd\samples\ntsc\d2v\telecine1.d2v",idct=2,cpu=0)
#mpeg2source("D:\kvcd\samples\ntsc\d2v\telecine2.d2v",idct=2,cpu=0)
#mpeg2source("D:\kvcd\samples\ntsc\d2v\telecine1_old.d2v",idct=2,cpu=0)
mpeg2source("D:\kvcd\samples\ntsc\d2v\telecine2_old.d2v",idct=2,cpu=0)

Telecide(order=FOrder(),guide=1,show=true)

Whenever Decomb found a pattern (not flag based) it showed an in-pattern 
message.
It only happened with the original streams, never with the mencoded ones.

An even stranger thing, as seen in the example above, is that a BFF stream 
becomes a TFF stream after the encoding when using softpulldown. That's 
why it looks interlaced all the time instead of the "3 progressive, 2 
interlaced" pattern.

But then I tried a script just containing:

SeparateFields()
trim(1,0)
Weave()

This cuts the first field from the first frame. The output looked 
completely progressive, no trace of a telecined pattern.


Conclusion: the only thing softpulldown does is cutting the first field of 
the first frame and then all looks interlaced and field order gets 
reversed. And the telecine pattern is completely gone, if it wasn't for 
that first field cutting it would be completely progressive. And that's 
not what's expected.


Bruno