Restoring Interlaced master that should have been progressive

[Jan Tokki]

Hi,
I have extensively used QTGMC with wonderful results for interlaced material, but I have a strange problem-child to deal with: it is an interlaced master that was WRONGLY exported as interlaced AVI.

It is obvious that the original material (fine motion graphics mixed with interlaced live) should have been exported as progressive.

What would be the best method to get back the horizontal resolution, that seems to have bee decimated in this file? Material is 4:3 SD-resolution.

[Sharc]

Nothing is obvious unless you upload a sample.

[Jan Tokki]

Got it, thanks. Attached a excerpt.

Looks like interlaced soccer game was scaled, then mixed with progressive speed chart and exported as interlaced. Pretty messy.
Getting wavey horizontals also with de-interlacing.
Suggestions welcome.
Have tried QTGMC pure, then some horizontal blurring, not sure what to try next.
Hmmmmmm....

[jagabo]

I think the problem here is that a 576 line frame was reduced to 434 lines by discarding pairs of scanlines. With 25 percent of the scanlines missing the near-horizontal lines are left with those wavy patterns.

[Sharc]

It's interlaced bottom field first

AssumeBFF()
QTGMC()
turnright().QTGMC(InputType=1).turnleft() #maybe helps somewhat

[Jan Tokki]

It's interlaced bottom field first

AssumeBFF()
QTGMC()
turnright().QTGMC(InputType=1).turnleft() #maybe helps somewhat

Thanks for the suggestion.
This does make the horizontal waves somewhat quieter, lower "frequency" but only a slight improvement.

Or maybe I have been staring at this sequence (over 2 hours of WM 2006!) so long I see annoyances everywhere where no normal person would be paying attention.

[Jan Tokki]

This code, suggested by Skiller as an antidote to "Interlaced Twitter" really did help with some shimmering of the horizontals but then smeared the graphics + subs more than I could accept.

Code:

Blur(0, 0.7, false).Sharpen(0, 0.4, false) #normal

Blur(0, 0.6, false).Sharpen(0, 0.4, false) #for less detailed sources

The sharpen() may seem counterintuitive but like this it works more like a broadcast low-pass filter that "thickens" details rather than just a blur.

I guess when this amount of vertical resolution info is gone, it is just gone.

[Skiller]

You used only one of the two lines, right (not both)?


If yes, I'm afraid that's about as detailed as interlaced video can be on the vertical axis without creating unwanted side-effects.

I guess when this amount of vertical resolution info is gone, it is just gone.

Yes, interlaced video simply cannot have the full vertical resolution which an entirely progressive playback chain from start to finish can.


Edit: I am mixing up topics. That code should not be used for the problems in this thread, or at least that's not what it is intended for.