Bizarre 720p source--how to go to DVD?

[cheer]

OK, I have a weird video source and I'm not sure what the best approach would be.

This is a 1080x720p (60 frames/sec) MPEG2 video recorded off OTA HD. HOWEVER...the video being broadcast really isn't HD. It's a 480i video being upconverted. To make matters worse, it's 4:3 letterboxed, so I end up with an upconverted rectangle in the center of my 16:9 TV with black bars all around.

So I figured I could just use DGDecode/Avisynth to crop all around, do the bt709tobt601, and resize to 720x480, then feed into an MPEG encoder which will give me something I can author using DVD-Lab or whatever.

But I'm concerned about what's happened to the framerate. Looking through it frame-by-frame, it sure looks like it started out life as a film source (which is what I'd expect), as I see 3 prog. frames followed by a pair of what appear to be interlaced frames. Except, of course, the whole thing has been upconverted to a progressive format...what's the least destructive way to handle this? Should I just feed it as-is into an MPEG encoder with the hope that it will spit out proper 480i, or...?

--chris

[scharfis_brain]

upload a sample to www.rapidshare.de so we can see what the problem is.

[cheer]

Outstanding idea. Here is a 10 second clip (http://rapidshare.de/files/23590051/720pupclip10sec.mpg.html).

Thanks!

--chris

[scharfis_brain]

This script will revert the video into anamorphic 704x480 23.976 for DVD.

mpeg2source("D:\FORUM\cheer\720pupclip10sec.d2v") #,cpu=6)
selecteven()
crop(160,90,-160,-90)
bicubicresize(704,480)
tdecimate()

[Guest]

best way to go to DVD? Please read and follow forum rules, specifically, rule 12: do not ask what's best. Thank you.

http://forum.doom9.org/forum-rules.htm

I have edited your title.

[cheer]

This script will revert the video into anamorphic 704x480 23.976 for DVD.
Way cool; I'll give that a go. So just to make sure I understand what is happening here:
SelectEven is tossing half the frames, presumably as the conversion from 30i to 60p just duped every frame anyway.
Crop...duh. :)
BicubicResize...any particular reason to use this over LanczosResize?
Tdecimate will pull things back to the original 23.976

I have some encoding questions but I'll take 'em to the appropriate forum. Thanks again!

[scharfis_brain]

BicubicResize...any particular reason to use this over LanczosResize?

Bicubic is faster and lanczos won't gain anything here except of raising existing comnpression artifacts.

[cheer]

@sharfis:

Thanks. Just wanted to let you know that this turned out gorgeous on DVD. (Only change I made was to do some mild sharpening with msharpen as the upconverted video from the TV station was a bit soft.) Thank you very much for your help!

--chris

[Dark-Cracker]

a bit late but i think this should do the same (without lost half of the field)

to remove the dups pattern.

Decimate(5) # changes AABBB to AABB
Decimate(2) # changes AABB to AB

++

[scharfis_brain]

decimate(5).decimate(2) won't work properly.

decimate(2).decimate(5) would.
but it is much slower than
selecteven().decimate(5)
and the result would be the same.