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Mystery Import Problem
This seems odd to me (if not impossible). It’ll take a little bit to explain the problem and everything we’ve already tried but I have no idea what’s causing the problem and need suggestions.
What We Did
We add a vector logo made in AI to a DV project composited in AE. The completed project is rendered out to a QT MOV and imported into Avid Xpress Pro. I can go through the specific settings and steps but the two most important things to remember here are that the file exported by AE and imported by Avid was one single video file with no alpha channel – and that the edges of the logo look 100% perfectly crisp, smooth, and anti-aliased.What Resulted
Click here to see a screengrab of the problem (which looks even worse when moving). On the left you can see the Quicktime file with nice, crisp, perfectly smooth edges all around. On the right you can see how crappy this looks after it is imported into Avid, with aliased “stairs” and blocky 90 degree angles all around. Yuck!Chicken or Egg?
Again, I’ll go over the specifics in a moment but here’s what I don’t understand… Since everything looks nice and crisp in the QT file I’d think the problem is caused during import into Avid, but then how is it only the logo that is becoming horribly aliased while nothing seems to be happening to the background? To answer my own question, I suppose it could be because the background is all soft subtle color changes with no hard edges, so perhaps it is happening but you just can’t see it. But it still makes me think that something is happening on Avid import rather than within the original After Effects project.Details
* We’re DV video all the way: 720w x 480h @ 0.9 non-square pixel aspect ratio (created in 0.9, QT is only square pixels so it looks wide, then 0.9 again in Avid).
* Yes the red is harsh and may bleed but that shouldn’t* be the cause of the problem because I did this same test with a blue color overlay and it still ended up with “stairs”
* This is the same process we’ve been doing for a long time so we know it used to work without this problem. We’ve never had this happen before a week or two ago, but now this is the 2nd consecutive project it’s happened to. We don’t know what in the process has changed (possibly by accident).
* The original logo was created in Illustrator. This latest project was using this the AI file and I was using the ‘continuously vectorize’ setting (but I suppose that’s not even important since we already knew the output looked sharp). But I’ve also tested it using a rasterized version of the logo that came from a Photoshop file and the resulting “stairs” was the same.
*** If I import a still graphic of this same logo, it does NOT alias into blocky stairs like this. My workaround for this project was to render everything in AE without the logo and then add the logo later in Avid. That was a still graphic and not imported video, but does that fact hint back towards AE possibly being the cause somehow?Any ideas of what to check out? And should I be cross posting this message in the After Effects forum since I’m not 100% sure where the problem is starting?
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3 Replies
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When you render from AE, are you rendering 720×480? If so, what codec?
When you import into Avid, are you selecting Non-Square/Maintain as the import option? Avid is 720×486, even when you work with DV. If you import 601 you’re stretching your graphic 6 pixels, and that may cause the crunch. Otherwise, change your Comp settings in AE to 720×486, rerender, then reimport into Avid using 601 size.
Is you timeline in Green/Green mode?
Are you rendering to fields from AE then properly interpreting the fields in Avid upon import? If you’re not rendering to fields from AE, are you selecting “None” for the field options upon import into Avid?
Have you hit Play in Avid to see if the stair stepping goes away? When you stop playback in Avid you’re only seeing 1 field, so that may also account for the stairstepping. I’ve often been disgusted by the graphics I import into Avid only to love them again when I hit play and watch them on my broadcast monitor.
Give us some more details based on my questions and we’ll see if we can get to the bottom of this.
Michael.
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Thank you for your help.
When you render from AE, are you rendering 720×480? If so, what codec?
My AE comps (CS3 if I haven’t mentioned the version yet) have always been the preset “NTSC DV”, which gives you the settings of “D1/DV NTSC (0.9) with a width of 720 and a height of 480. When I render most of my settings are to use the same settings as the comp. The codec I use for Quicktime is Animation.
When you import into Avid, are you selecting Non-Square/Maintain as the import option? Avid is 720×486, even when you work with DV. If you import 601 you’re stretching your graphic 6 pixels, and that may cause the crunch. Otherwise, change your Comp settings in AE to 720×486, rerender, then reimport into Avid using 601 size.
I’ve never heard of DV being 720×486 in Avid before. My Avid import settings have always been an Aspect Ratio, Pixel Aspect of 601/709 non-square. But I did just test out two of your suggestions here. I re-rendered my comp at 720×486 and imported under 601 as before. I also tried re-importing my original 720×480 under the (non-601) “Maintain, non-square”. Unfortunately both ways resulted with the same edge issues.
Now speaking of AE settings, I just now noticed that the default NTSC DV setting says 27:20, while the NTSC D1 setting (720×486) shows the more familiar 4:3 ratio. Not to get off track but I found that surprising. Anyway, another export setting I have under “Video Output > Color:” is “Premultiplied (Matted)” and not the other choice of “Straight (Unmatted)”. I don’t know much about those two choices. I haven’t changed these settings for a long time and this problem is more recent, but do you think that may be a factor?
Is you timeline in Green/Green mode?
Do you mean that quality setting in Avid that can sometimes be half yellow / half green? If so, then yes it’s all green.
Are you rendering to fields from AE then properly interpreting the fields in Avid upon import? If you’re not rendering to fields from AE, are you selecting “None” for the field options upon import into Avid?
This part I don’t know. I don’t see any options for rendering to fields. Maybe I am already but where would I look for that setting. As for Avid, I’m importing “Non-interlaced” as the field order, but I did just run another test under “lower field first” with no improvement.
Have you hit Play in Avid to see if the stair stepping goes away? When you stop playback in Avid you’re only seeing 1 field, so that may also account for the stairstepping. I’ve often been disgusted by the graphics I import into Avid only to love them again when I hit play and watch them on my broadcast monitor.
I know exactly what you mean about video sometimes looking much better when playing, but that is not the case here. It actually looks much worse, as (for some reason) Avid can’t decide whether these straight lines (like on the left inside of the C) should be either red or very very dark, so it appears to flicker back and forth between red and very very dark as it slowly zooms larger. It looks bad on an NTSC monitor and just horrible on the Avid monitor.
I suppose seeing the motion would help a ton. Here is a link to a 2 second Quicktime file exported from the Avid (not the original straight from AE). This test has a lighter background to make it easier to see. It’s especially obvious on the inside curves of the C and the M. Also notice that against this lighter background it’s much easier to see that there actually is a sharp edge around the letters but it’s very dark, and its the color that borders that edge that’s actually “stairstepping” inward away from the edge, creating those dark spaces. Hard to describe in words but you see what I mean, right?
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