Resize and Deinterlace

[wesdood]

I have some that was shot in 1080i. The final product needs to be 720p. I'm going to need to matchmove the shot.

Would I get better results if I deinterlaced the footage before or after resizing the video?

[DJMartin]

Don't know what kind of programs you have availiable. But if I were to do that, I would create a 1080i project in premiere, and export as 720p tifs. Then I have deinterlaced footage with the same format that will be used later in the project. In CS4 i'm sure you could drag it right into Adobe Media Encoder.

[Andreas.Jablonka]

i would deinterlace the footage and track on the higher res1080 plate. more detail for your tracker to work with.

[wesdood]

Don't know what kind of programs you have availiable. But if I were to do that, I would create a 1080i project in premiere, and export as 720p tifs. Then I have deinterlaced footage with the same format that will be used later in the project. In CS4 i'm sure you could drag it right into Adobe Media Encoder.

That came out fine. Thanks.


i would deinterlace the footage and track on the higher res1080 plate. more detail for your tracker to work with.


I've tried that before but I had problems with my CG sliding a little on the resized footage.

[Dotcommer]

i would deinterlace the footage and track on the higher res1080 plate. more detail for your tracker to work with.

Well, keep in mind, deinterlacing loses half your data, so actually you'll probably not get as good of a track because of that.

[DJMartin]

Well, keep in mind, deinterlacing loses half your data, so actually you'll probably not get as good of a track because of that.
Does it? I'm on thin ice on this one so don't kill me if I am wrong.

But let's say a 720p video is 10mb, in 1080i it is double the size, but every 2nd line so this also result in a 10mb video. A 1080p would be twice the amount of lines so double the size - 20mb.

If his source 1080i is converted to 1080p it has to double in size, so you will not lose any data. But actually double it.

Am I totally lost?

[georgeivan]

Maybe you can upload the video to megaupload or rapidshare in full res.

It more easy to talk about something with a sequence on hand.

Some of us could have free time waiting renders :)

[Dotcommer]

Does it? I'm on thin ice on this one so don't kill me if I am wrong.

But let's say a 720p video is 10mb, in 1080i it is double the size, but every 2nd line so this also result in a 10mb video. A 1080p would be twice the amount of lines so double the size - 20mb.

If his source 1080i is converted to 1080p it has to double in size, so you will not lose any data. But actually double it.

Am I totally lost?

Riiight, but remember the actual process of "deinterlacing" is removing every other line of data and duplicating the scan above it. So you're essentially losing half your data because you're throwing out every other line and duplicating the remaining data to fill in the gap.

[DJMartin]

Riiight, but remember the actual process of "deinterlacing" is removing every other line of data and duplicating the scan above it. So you're essentially losing half your data because you're throwing out every other line and duplicating the remaining data to fill in the gap.
I thought that was the process of interlacing a video, where you remove every other line of data and duplicating the scan above it. And deinterlacing is when you create every other line of data from a interlaced image so you get a deinterlaced image.... Could be wrong.

[Gravy]

Interlacing is simply splitting the original image into two fields. It does it with multiple lines (classed by odd and even). In broadcast it's then broadcast one field after another to save bandwith.

So if you do a straight deinterlace you will loose data. You can use methods such as blending, averaging etc. Your probably better off just tracking one set of the fields though.

If it was shot progressively however then the interlacing won't make a difference it's simply just split up into fields. However if it's filmed interlaced you could have slight offsets between the fields.

http://en.wikipedia.org/wiki/Interlacing

[Andreas.Jablonka]

Interlacing is simply splitting the original image into two fields. It does it with multiple lines (classed by odd and even). In broadcast it's then broadcast one field after another to save bandwith.

So if you do a straight deinterlace you will loose data. You can use methods such as blending, averaging etc. Your probably better off just tracking one set of the fields though.

If it was shot progressively however then the interlacing won't make a difference it's simply just split up into fields. However if it's filmed interlaced you could have slight offsets between the fields.

http://en.wikipedia.org/wiki/Interlacing

exactomundo! i was scared by the answers above, thanks gravy!

[Dotcommer]

Scared huh? I don't know... I thought I explained it pretty well... I'm not wrong, thats for sure.

[wesdood]

I did all of the things mentioned in here. I'll post up the results tomorrow when I get the chance.

[Diogo Girondi]

It will all depend on the footage you have at hand, what you're trying to do and how you need to output it. Sometimes a straight deinterlace interpolate might be sufficient, in others you may need to use motion estimated deinterlace and depending on how things are field wise, deinterlacing only the moving parts might work. But if you need to reinterlace things in the end you're pretty much stuck with deinterlacing it to frames using a duplicate method. Unless of course loosing data isn't much of a problem.

[wesdood]

Rapidshare (http://rapidshare.com/files/278216736/upload.zip)

The deinterlacing was done in shake.

[georgeivan]

Well deinterlaced looks pretty solid.

You are going to use it in nuke or another 3d app?

[wesdood]

Well deinterlaced looks pretty solid.

You are going to use it in nuke or another 3d app?

I'm going to do the tracking in SynthEyes, and comp the shot in Nuke.

Question - In the script you uploaded, what does the environment node do?

[georgeivan]

Nothing just to see the objects