Interlaced video, 1st pixel row in top field is black

[kumi]

I have a NTSC DVD with interlaced material, and somehow, all the top-most fields have a black first row of pixels:

http://i23.tinypic.com/er0jns.png


But the bottom fields are OK:

http://i20.tinypic.com/fmkz1d.png


I wouldn't mind, except that I'm deinterlacing this video, and the results at the top of the frame are temporally unstable and generally annoying:

http://i21.tinypic.com/10fnkh3.png



How to alleviate this problem? :stupid:

[Guest]

We don't ask for "best" around here, but here is one possibility:

Use Simon Walters' Border Control filter to replace the top line with a copy of the second line (use the Smear operator). Then apply your deinterlacer.

http://www.geocities.com/siwalters_uk/fnews.html

Maybe:

BorderControl(YTS=2)

If that doesn't work, I have another idea. Please let me know.

[kumi]

Thank you very much neuron2, I think your suggestion is working just fine. My script is:

MPEG2Source("C:\foo.d2v",idct=7)
BorderControl(YTS=2)
AssumeTFF()
TDeint(order=-1, type=2)

Just out of curiosity, what was your other idea?

[Guest]

Just to find a way to copy the second line to the first line using scripting.

[kumi]

OK cheers, that's the avenue I was persuing before you told me about BorderControl.

[themostestultimategenius]

Just wondering, is it possible to smear just a part of the bottom few lines?

http://img34.picoodle.com/img/img34/6/10/19/f_1m_1e50fe9.png

[Guest]

You'd have to modify the filter or write a script to split the video into two pieces, apply the smear to one, and then re-stack them.

[scharfis_brain]

x= horizontal value where black line starts

stackvertical( crop(0, 0, 0, height - 1), stackhorizontal( crop( 0, height - 1, x, 0), crop( x + 1, heigth - 3, 0, -2)))

that should fix this problem in theory. not tried it

[foxyshadis]

Won't work in YV12, will have to be converted to YUY2 or RGB. Creating a mask is another solution, especially if it varies across the video.

[themostestultimategenius]

You'd have to modify the filter or write a script to split the video into two pieces, apply the smear to one, and then re-stack them.

I see. Thanks for the replies =)

I'll try out scharfis' suggestion when I'm not so busy. If it doesn't work I'll mask it as foxy has suggested.

[Mug Funky]

i used this one back when i was encoding DVDs:

function linefill (clip c, int "offset")
{
offset = default(offset,1)
offset = offset >= c.height/2 - 4 ? c.height/2 - 8 : offset
c.lanczosresize(c.width,c.height-(offset*2),0,1,c.width,c.height-(offset*2)).lanczosresize(c.width,c.height,0,-offset,c.width,c.height)
}

advantage is you get single line precision without going out of yv12.

disadvantage is it does a line on both the top and bottom of frame, and can't cut in halfway through a line. usually it's enough :)

this could quite easily be hacked to do what's needed though.

these days i don't bother because once you master to tape, hey presto the lines come back - don't ask me why this happens in the days of all-digital chains, but there was a reason for it back in the analog days.