After-Effect aliasing problem

[kiwikiwi]

Hi all,

As it is the first time i post here, i would like to warn you guys that my english is not that good, and certainly not good enough but i'm working on it, please excuse me for that.

Well, my problem is :

I am used to after-effect cs3 & Premiere cs3 and i usually dont call for help but this problem is quite frustrating for me.
I have several clips in .avi exported from premiere with thoses settings (DV Avi - DV NTSC - 720/480 - 29,97i/s & Pixel 0,9). The quality of clips are excellent, if i re-import them in premiere or if i read them with any player it's just perfect to me.

But as soon as i import them in After-effect, i have a big aliasing problem. Even with a brand new composition with exact same settings (DV NTSC etc...) I post here an screenshot of my problem so you can see by yourselves.

I can also import any other clip in my composition without any problem of aliasing, it's just on the clips that i extracted from the camera ( and then modified in premiere... and then exported to avi .. blabla).

I hope someone can solve this, even if i have to re-extract clips from camera (.NTS 1440/1080)

Thanks in advance.



*edit* It's not the "draft" quality setting that you can set any layer in ae

[jagabo]

It looks to me like AE is deinterlacing with a discard field and resize. If this is only in the display while working in After Effects (not in your processed output) I wouldn't worry about it.

[SLK001]

I'm not sure that I can see what you are talking about. What do you mean by "aliasing"? Do you mean "more blurry"? It looks to me that the AE thumbnail is a little blurrier than the Premiere thumbnail. It could be that Premiere is "bobbing and rescaling" a single field, while AE is blending top and bottom fields together. But that's just a guess.

Are the outputs from both programs different?

And next time, post screenshots of the same frame. Two different frames could be completely unrelated.

[jagabo]

Don't you see the jagged edge on the pillow (and other places) in the AE shot?

[SLK001]

Don't you see the jagged edge on the pillow (and other places) in the AE shot?

Not all that clearly in these "thumbnails". What did you use to see them... a microscope? I get no links to full sized screenshots.

[Cornucopia]

Maybe AE isn't interpreting the footage correctly...

It should be interpreted as "Interlaced", "0.9 Pixel Aspect Ratio (DV-NTSC)". Check to make sure you have the field dominance set right also.
Don't know why it wouldn't interpret it correctly automatically- mine does.

Once imported into project, right click and select "Interpret Footage" (or similar phrase).

Next time, show FULL 1:1 screenshots. Thumbnails aren't good for examining.

Scott

[jagabo]

I don't think these are thumbnails but rather crops. Here's a 2x nearest neighbor enlargement:



Now do you see the aliasing? It looks like a discard field and resize deinterlace to me. If the aliasing wasn't obvious in his original post there is something wrong with your computer/monitor.

[SLK001]

I view on a 1280x1024 screen. With the original "thumbnail" size of 242x242, the aliasing pretty much falls into the cracks. If I drop my screen resolution to 1024x768, then the aliasing is starting to show.

But once I do see it, I agree that there is something amiss here. Unless the camera is panning across the bed, even an interlaced video shouldn't be showing this aliasing. That's the problem with trying to analyze a video problem with a single picture.

[jagabo]

I view on a 1280x1024 screen. With the original "thumbnail" size of 242x242, the aliasing pretty much falls into the cracks. If I drop my screen resolution to 1024x768, then the aliasing is starting to show.

I'm running a 20" LCD at 1680x1050 (native res) and the aliasing obvious in the original image.

[kiwikiwi]

Hi,

Big thanks for quick answers, i really appreciate it.

And that was Cornucopia who aimed right, i just had to go manually change the upper/lower field in the footage itself.

Right click > Interpret Footage > Main > Fields & Pulldown

Thanks a lot guys and sorry for the thumbnails, i will remember that next time coz this site is definitely in my fav now =)

See You

Kiwi