Bad PAL telecine dvd help

[spiritgumm]

Bought this dvd from Europe, and unfortunately the telecine is weird. 25 fps progressive, but every 5th frame is interlaced or overlayed with the 6th frame. The ghosting looks jerky on playback, hard to believe there were no customer review complaints. I original planned to convert to Ntsc, but I dont think it's salvageable unless someone has a solution. I've seen AVI's of a retail dvd that look perfect - they might have used another retail release, but the AVI's were made before other dvds were released. Thanks for any help.

[davexnet]

I had a public domain film called "Hell Below" that had similar frame blending. I gave up on mine.

It will be interesting to see what the consensus is.

[LigH.de]

Best look fieldwise at it. If there is a regular pattern, then there is a chance. Just blending may make it harder...

[jagabo]

Every 4th frame is a blend of an original frame and the frame after it. You can unblend the clip as follows:

src=Mpeg2Source("VTS_01_1.demuxed.d2v", CPU2="ooooxx", Info=3) 

unblended=Overlay(src, src.Trim(1,0).ColorYUV(gain_y=-128,cont_u=-128,cont_v=-128), mode="subtract").ColorYUV(gain_y=256,cont_u=256,cont_v=256)

zero = src.SelectEvery(4,0)
one = unblended.SelectEvery(4,1)
two = src.SelectEvery(4,2)
three = src.SelectEvery(4,3)

Interleave(zero,one,two,three)

The problem with this code is it will fail an a break in the pattern. There may be another way to select the unblended frames. I'll have to think about it. Also, the unblended frames are pretty blocky and noisy. It would make sense to reduce that noise.

[spiritgumm]

Neat script. Isnt blend detection part of other filters that could make it simpler?
I did find one negative review for the dvd playback on an Italian site. I know there's a good copy out there, so I ordered the German bilingual release. That got a good technical review, but they mentioned it has German subs in a few untranslated spots. Hopefully not hard subs.

[jagabo]

I didn't work out a way to automatically detect which frames need unblending. But I made the unblending into a callable function that will make it easier to use:

##########################################################################
#
# Deblend one frame out of every group of four.  The blended frame must
# be a 50:50 blend of that frame and the frame after it.
#
# Deblend1of4(clip c, int which)
#
#    c = the video to be deblended, must be YUV
#    which =  which of the four frames (0 to 3) is to be deblended.
#
# the algorithm:  The blended frame is assumed to be a 50:50 mix of
# that frame (M) and the next (N):
#
#    blended = (M + N) / 2 
#    blended = M/2 + N/2
#    blended - N/2 = M/2
#    (blended -N/2) * 2 = M
#
##########################################################################

function Deblend1of4(clip c, int which)
{
  # unblend all frames, only one will be useful
  unblended = Overlay(c, c.Trim(1,0).ColorYUV(gain_y=-128,cont_u=-128,cont_v=-128), mode="subtract").ColorYUV(gain_y=256,cont_u=256,cont_v=256)

  # substitute the one we want, leave the others unchanged
  zero  = (which==0) ? unblended.SelectEvery(4,0) : c.SelectEvery(4,0) 
  one   = (which==1) ? unblended.SelectEvery(4,1) : c.SelectEvery(4,1) 
  two   = (which==2) ? unblended.SelectEvery(4,2) : c.SelectEvery(4,2) 
  three = (which==3) ? unblended.SelectEvery(4,3) : c.SelectEvery(4,3) 
 
  Interleave(zero,one,two,three)
}

##########################################################################

src=Mpeg2Source("VTS_01_1.demuxed.d2v")
Deblend1of4(src, 1)

This way you deblend different portions of the video as needed:

part1 = src.Trim(0,1000).Deblend(1)
part2 = src.Trim(1001,2000).Deblend(3)
part1 + part2

[spiritgumm]

I appreciate the work on that. I would be applying it to the whole movie, and I'm not sure it would be worth it on this copy.
I just received an another retail release with more normal progressive PAL video. Unfortunately there are scenes where the picture shakes. There's also a spot where a few frames are missing which throws off the rest of the audio. I know there's a perfect PAL retail release somewhere since I downloaded an MKV rip.