The need to render interlaced?

[David Frisk]

Thank you very much Steve. I definitely get it now. I didn’t realize that upon render that AE would still interpolate my footage if need be. That definitely would make a difference, huh? Such a smart program that AE is 🙂

Anyway, thanks again, and thank you to everyone who tried to explain it to me the first time around. You guys are awesome!

[Andrew Yoole]

Simplest way to get clear about this is render a test. Animate some text or a solid moving right to left over a few seconds. Render interlaced and non-interlaced copies. Import both into your Avid and watch them on an interlaced monitor. The difference will be glaringly obvious.

[Steve Roberts]

Heh. Yeah … enough talk. Let’s render a test! 🙂

Just to restate, AE cannot interpolate new fields in 30p footage without a plugin, but it can interpolate fields in animation that it creates during that render.

So yes, it can create fields in the animation of that moving circle, an animation that was created in that project for that render.

[Bobby Mosaedi]

i dont know how avids import media, but i edit on a media 100. one reason i have to render interlaced is so i can do a quick import into my NLE. if its not interlaced it will have to re-render upon import essentially doubling the time and steps it takes to get a rendered composition into the NLE.

[David Frisk]

Yea, I knew it couldn’t interpolate new fields from the footage, and I just figured it was that way for anything, even with animation created during the render. I should have known better though. Thanks guys, appreciate it.

[Steve Roberts]

Hmm … why don’t you just tell the M100 that the footage is interlaced?

Although … I believe that the extra time is taken because the footage wasn’t rendered to the M100 codec. I think that’s the issue, and that fields vs. frames doesn’t matter. If the footage is compressed to the M100 codec, it will be imported quickly. If I recall, the M100 codec doesn’t have a “no fields” option?

Try this if you want, Bobby: make a field-rendered anim in AE and render to the Animation codec. Re-render to the M100 codec. Then make a frame-rendered anim in AE and render to the Animation codec, then re-render to the M100 codec. My guess is: M100 will import both M100 clips nicely, because the codec is the issue.

[Brendan Coots]

Rendering to fields WILL affect the resulting motion of your animation/graphics. You can test this by animating a colored box moving from left to right across your screen. Do one moving fast and another going much slower. Render out to a progressive file and one interlaced, then play both back on an ntsc monitor. You should notice the progressive-rendered file is more choppy, especially at slower animated speeds. In short, I render to fields any time there is horizontal motion or slower animations of any type.

I am no Avid expert so this may be subject to debate, but you may also be saving your editor time on the import if the file is already rendered to fields (saving Avid the additional calculating time). Don’t know about your shop, but most places the Avid suite is vastly more expensive than a graphics station, so there is a cost motive for doing as much as possible on your end.

[Bobby Mosaedi]

oh i always render out to the media100 codec, all i was getting at was that some NLEs can accept multiple codecs/file types and play them instantly, but the media100 is not. obviously have to render with fields and with a lower field dominance , has to be 720×486, broadcast safe colors (i think). if all these requirements are met, the file will just “pop” into the bin instantly. otherwise, there will be a nice long wait as you watch the file re-encode itself though the hardware.

interestingly enough, the newer version of media100 can play back in real time, instant import of animation files w/alpha, FCP DV files, legacy media100 clips, even mix SD 640×480 and 720×486 or HD clips in the same timeline. pretty impressive

[Rich Rubasch]

You guys keep suggesting that you move an object from right to left, but this field test is more apparent with a smaller object with hard edges moving vertically. In a Frame rendered clip the resulting vertical motion will reveal the judder more apparently that if it was moving left to right. Likewise, in a field rendered clip of the same vertical motion will reveal the smoothness of the 60 fields.

So do your test with a small hard edged object falling vertically…

Rich Rubasch
Tilt Media

[Spooky]

This is an interesting topic. For the last couple of years, I’ve been exporting out without fields for DVD as (correct me if I’m wrong), it can play progressive. I shoot and capture my footage as 30fps progressive and composite in AE as 29.97fps fields off. Am I doing a “bad thing.” Everything has always looked great.

What’s your workflow? Here’s mine on a typical project:

If using video I shoot 30p
if combining 3D I output to single-frame IFF files at 30fps.
AE comps at 29.97 no interlacing
Export either as Animation with no interlacing
Either directly import DVD Studio Pro or convert to MPEG-2 with Compressor.

Now not being at my main studio right now I can’t check my settings, but doesn’t DVDSP import progressive files and leave them as such?