Transferring VHS which is partially interlaced and partially progressive

[wcndave2]

I've found at least one tape like this, and it chops between them pretty fast and frequently. Sometimes there's just one second of interlaced, then a second of progressive, then a second of interlaced...

At other times it's mostly progressive.

I am thinking that progressive was used for certain types of shots (close up and mid) and that interlaced was used for wide shots.

I can't enter timings for every transition in AVS, so I feel my options are:

1. do not de-interlace to retain best quality for 90% of the time
2. interlace everything so that nothing looks comb-like...

Is there any other/clever tactic or tool?

Thanks!
Dave

[dellsam34]

There is another option, edit the interlaced sections apart, de-interlace them and merge back with the other de-interlaced sections, But it is much easier to de-interlace everything and the de-interlacer treats progressive footage as interlaced frames and just repeats those fields hoping that little to no damage will occur.

[Sharc]

Assuming your analysis is correct and your "interlaced" sections are not telecined stuff: Deinterlace everything using a high quality deinterlacer like QTGMC and encode and flag it as progressive.

[VWestlife]

A lot of big-budget 1990s TV shows (like Friends, Seinfeld, 90210, etc.) were shot on film, or later on 24p "film-look" digital, and then edited and broadcast as 60i, so if you try to do inverse telecine to get it back to 24p, almost every scene change will break the pulldown cadence and ruin the result.

So don't tear your hair out trying to put Humpty Dumpty back together again. Just de-interlace the whole thing to 60p (or 50p for PAL) using QTGMC and move on with your life.

[jagabo]

2:2:2:2:2:2:2:2:2:2:2:3 pulldown (12 film frames to 12.5 video frames, ie, 24 film frames to 25 video frames) was sometimes used for film sources and will alternate between a half second of interlaced and a half second of progressive. If that's what you have it's easily restored to all progressive frames at 24 fps in AviSynth.

[Sharc]

2:2:2:2:2:2:2:2:2:2:2:3 pulldown (12 film frames to 12.5 video frames, ie, 24 film frames to 25 video frames) was sometimes used for film sources and will alternate between a half second of interlaced and a half second of progressive. If that's what you have it's easily restored to all progressive frames at 24 fps in AviSynth.

Yes. FWIW attached an example of Euro-pulldown. The 24 fps progressive film frames can be restored with Avisynth

TFM().TDecimate(cycle=25)

[wcndave2]

Thanks. I can't do the separate parts and put back together as there's hundreds of changes in just 5 mins of footage.

I have just deinterlaced, although that does lose some of the original information. Just wondered if anything like QTGMC could be smart enough to switch between modes depending on what it recognised.

Thanks again!

[lollo]

Just wondered if anything like QTGMC could be smart enough to switch between modes depending on what it recognised.

Thanks again!

You can try something like:

TDeint(mode=0, full=false, cthresh=9, chroma=false, MI=16, edeint=QTGMC(FPSDivisor=2), emask=TMM(mode=0), slow=2)

but the interlaced part will be "penalized" because with QTGMC(FPSDivisor=2) you loose half of the motion.

You can change it to:

TDeint(mode=1, full=false, cthresh=9, chroma=false, MI=16, edeint=QTGMC(FPSDivisor=1), emask=TMM(mode=1), slow=2)

but it really depends on the source.

[Sharc]

Thanks. I can't do the separate parts and put back together as there's hundreds of changes in just 5 mins of footage.

Did you check for Euro pulldown at all? For more help upload some seconds of your exotic source showing such "random" changes.