Scaled down DV footage precomp loses resolution
by Jessica Lynch
on
Oct 28, 2008 at 6:34:20 pm
The original comp is 720x480 .9 pxl with MiniDV footage. It is nested in a 480x270 .9px composition. When I scale down the original comp so that it fits in the smaller one, the footage appears blurry.
In the past I have used the Sharpen effect as a workaround.. am I missing something?
Re: Scaled down DV footage precomp loses resolution by Dave LaRonde on Oct 28, 2008 at 7:16:03 pm
[Jessica Lynch]"The original comp is 720x480 .9 pxl with MiniDV footage."
The footage is obviously DV, but let's learn more: is it garden-variety 29.97 interlaced footage? Was it shot at 30p? If it was shot at 24p or 24pa, did you remove the pulldown?
[Jessica Lynch]"When I scale down the original comp so that it fits in the smaller one, the footage appears blurry."
Did you interpret the field order properly? For interlaced 29.97 DV, it's lower field first.
Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA
Re: Scaled down DV footage precomp loses resolution by Kevin Camp on Oct 28, 2008 at 8:46:26 pm
in ae, select the footage in project window, then choose file>interpret footage>main... make sure that ae is set to separate the fields with the proper order and then check the option for preserve edges.
now, in the comp where the footage is (the nested comp), select the footage then choose layer>quality>best (this would be the normal setting, but it can sometimes get changed).
now, go to the final comp and make sure that the same quality setting is set to best for the nested comp.
just to make sure... you're maintaining the 29.97 frame rate throughout all the comps, correct? you may have some issues if you are changing frame rates and are telling ae to generate new frames, either via a plugin (like timewarp) or frame blending.
Re: Scaled down DV footage precomp loses resolution by Jessica Lynch on Oct 28, 2008 at 8:53:15 pm
I checked the "preserve edges" box (which was previously unchecked).
All layers are set to best quality.
Framerate is consistent throughout the project.
No special plugins are used.
Does this happen to you when you scale down a precomp?
Re: Scaled down DV footage precomp loses resolution by Dave LaRonde on Oct 28, 2008 at 9:50:07 pm
Well, the precomp's half-size, so you're going to lose something, but it shouldn't be going soft.
Where does it look soft: in a media viewer like Quicktime or Windows media Player or in AE?
And while I applaud your efforts to dot all the i's and cross all the t's with your .9 pixel-aspect-ratio smaller comp, I'm scratching my head why you'd need it. If it's destined for the web, you might be better off using something that's in square pixels. 480x360 or 260x240, perhaps?
You can get the DV-sized to comp to fit by using the "scale the layer to fit the comp size" keyboard shortcut: Command-Option-f (mac) or Ctl-Alt-f (win).
You might give it a shot and see what happens.
Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA
Re: Scaled down DV footage precomp loses resolution by Jessica Lynch on Oct 28, 2008 at 10:36:07 pm
It looks soft in AE. I rendered out an uncompressed .avi and got the same results.
Specifically, I have an actor on a greenscreen. I drew a mask around the actor and precomped it. I then applied the keylight effect to the precomp and added some color correction. I precomped this also, as some of the CC was done on an adjustment layer that I didn't want to affect the background I placed the actor on.
I nested this into a 16:9 480x270 comp, because that is the destination size. I will be encoding the finished video to an .flv and streaming it online.
I use .9 par because the footage is horizontally stretched when using square pixels. Is there a way around this? I did try it, though, and it still did not fix my problem with the footage going soft.
Re: Scaled down DV footage precomp loses resolution by Dave LaRonde on Oct 28, 2008 at 10:44:59 pm
Now I understand about the size, I guess. I always thought 320x240 was a pretty standard size for flash video.
If you're sure you've interpreted the DV field order properly, and you're also rendering it in that order, I can only think of one more thing:
Did you apply any blurs to any layers that you decided not to use, but didn't remove? AE defaults to rendering ALL effects whether they're turned on or not.
Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA
Re: Scaled down DV footage precomp loses resolution by Jessica Lynch on Oct 28, 2008 at 11:18:17 pm
I work for a streaming video company that deploys many different players with varying sizes according to what the client wants. They usually prefer to have a 16x9 video window that is as large as possible but also practical. YouTube uses a 480x360 flash video player, which I believe is another pretty standard size.
Unforutnately I did not apply any blurs, so the problem is still unresolved. The problem atually occurs even when there are no effects applied at all.
BUT, I am going to continue to use the Sharpen effect as a workaround, which works OK.. I just thought I might be missing an obvious solution, such as the Continuously Rasterize switch or something.
Re: Scaled down DV footage precomp loses resolution by Kevin Camp on Oct 29, 2008 at 2:49:25 pm
i doubt that this will help you problem, but your 480x270 comp should be square pixel to maintain 16:9... with a .9 par, the 480x270 comp is actually an 8:5 ratio. ae won't have any trouble accommodating the differing pars...
i've tried to recreate your problem, but i can't... i'v taken an ntsc, interlaced clip into a full sized comp, then taken that comp into a 480x270 comp, did fit comp width and it looks fine. i also compared it to bringing in the clip without the precomp and doing fit to comp, and it looked exactly the same...
i could get a slightly softer image if i went into preferences>previews and enabled opengl and set the preview to use opengl acceleration... so you might check to make sure that opengl is disabled inthe preview pref, but, unless you were also using opengl for renders (which would need to be set in the render settings) it should not effect your rendered file.... well, potentially if you were using file>export....
Re: Scaled down DV footage precomp loses resolution by Kevin Camp on Oct 29, 2008 at 5:13:47 pm
you are seeing the .9 par comps as square pixels on a computer monitor, so the image is actually stretched horizontally by 10%, when you view the same footage is a square pixel comp that is corrected.
if you use ae's rather cruder pixel aspect ratio correct toggle on a non-square pixel comp (it's the little icon at the bottom of the preview window that looks like a rectangle with a 2 headed arrow over it), ae will show what the proper aspect ratio would look like on a tv... well, kind of, it will look a bit jaggy, like i said it's rather crude.
anyway, rest assured that ae is properly handling the pixel aspect ration conversion as long as the footage is interpreted with the correct pixel aspect ratio...
