Psychedelic Strobing Moire Pattern

Psychedelic Strobing Moire Pattern

on Jul 19, 2010 at 4:48:04 pm

Thanks in advance for all the help, past, present, and future!

Forgive me, as I originally posted this over at lafcpug, as they have a specific, " Apple Compressor," forum, and that is where this problem is occuring. They were not able to offer any great solutions, other than using the anti aliasing slider in Compressor, which will reduce the quality for the entire project, perhaps with no great result either. (Now, if I could keyframe those sliders in Compressor, maybe... well, keep dreaming.)

It may just be a lesson learned.

But, then I thought that maybe there was something in AE that could be done, (other than a mask, as this character is in frame a good five minutes. And, this guy doesn't stop moving, as you will be able to see in the vid.)

The FCP project is HDV 720p, and I am editing and exporting Apple ProRes 422.
The moire issue was not noticeable on my QT export from FCP, even blown up on a 46" 1080p HDTV.

But once Compressor finished with it, the moire pattern is unbelievably distracting.
I know, don't shoot anything with crazy horizontal lines like that. But this was on the fly shooting down in Haiti after the quake, and wardrobe for a doc subject was not on the list.

Btw, I was initially not happy with the first DVD's I created. The down conversion from 720p to DVD, certainly didn't help, but I am much happier with my newly tweaked compressor settings, such as enabling frame controls for downsizing, helped a lot.

Except for the psychedelic moire.

Anyway, here is a link to a short clip depicting the problem. As this clip hasn't been encoded to m2v and muxed to DVD, and then blown up, it doesn't really show the moire, but you will see what I mean. (I am also having a similar problem with piles of rubble in the background of hand held shots. Same sort of thing, but without the psychedelic effect.)

Here is a link to the vid, off site.

http://img834.imageshack.us/img834/9611/crzyshirt.mp4

And here is a still, if the vid doesn't load for some reason.

And for the heck of it, a still of the rubble which after encoding, doesn't have a moire problem, but appears to "shake," behind the subjects. It is a hand held shot...

Re: Psychedelic Strobing Moire Pattern

by Dave LaRonde

on Jul 19, 2010 at 4:57:25 pm

Hey, fine details are tough for video. Get used to it. Try to avoid it.

Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA

Re: Psychedelic Strobing Moire Pattern

on Jul 19, 2010 at 5:01:37 pm

Thanks again Dave. I just finished replying to your last post.

"Hey, fine details are tough for video. Get used to it. Try to avoid it."

I was prepared to hear that. And, to take the medicine.

I just figured I might as well put it out there...

Best,

Richard

Re: Psychedelic Strobing Moire Pattern

by Darby Edelen

on Jul 19, 2010 at 5:03:24 pm

[Richard Mamary] "Btw, I was initially not happy with the first DVD's I created. The down conversion from 720p to DVD, certainly didn't help, but I am much happier with my newly tweaked compressor settings, such as enabling frame controls for downsizing, helped a lot."

So you're going from an HD source to an SD output?

If that's the case then it's most likely an interlacing problem. Make sure that your field order is correct (this could potentially account for the 'shaking') and if need be add a small vertical blur to the footage before or during compressing (I believe compressor has a filter to accomplish this).

Darby Edelen

Re: Psychedelic Strobing Moire Pattern

by Darby Edelen

on Jul 19, 2010 at 5:05:24 pm

Also, if you're going from a 23.98 source to DVD, don't change the frame rate. MPEG-2s encoded for DVD at 23.98 are 'smart' (or more properly, the DVD players that play them back are smart) and will introduce a pulldown to 29.97 on playback.

Encode at 23.98.

Darby Edelen

Re: Psychedelic Strobing Moire Pattern

on Jul 20, 2010 at 8:26:29 am

Thanks Darby for weighing in.

"So you're going from an HD source to an SD output?"

Yes. Its an HDV 1280x720 29.97 "progressive" timeline, exported out same settings as Sequence, Apple Pro Res 422. The footage is still progressive, as I understand it...
Here is info on the output file.

"If that's the case then it's most likely an interlacing problem. Make sure that your field order is correct."

In Compressor when I export using, "Automatic Mode," in the Quality Tab it has also selected, "Progressive," (grayed Out.)

"Confirming the m2v is progressive, here is media info on the m2v that Compressor encoded.

So where is it becoming interlaced? In the DVDSP mux?

Any thoughts?

Re: Psychedelic Strobing Moire Pattern

by Darby Edelen

on Jul 22, 2010 at 12:05:22 am

It sounds like interlacing is not the issue here.

If you have time to run some tests, try resizing one of the problematic sequences in AE and running that through Compressor without making any changes to frame size.

Darby Edelen

Re: Psychedelic Strobing Moire Pattern

on Jul 22, 2010 at 6:52:07 am

Thanks again Darby,

"Btw, I was initially not happy with the first DVD's I created. The down conversion from 720p to DVD, certainly didn't help" - my quote.

"If you have time to run some tests, try resizing one of the problematic sequences in AE and running that through Compressor without making any changes to frame size." -your quote

Btw, I just wanted to be clear, I have been exporting 1280x720 progressive, and importing that into Compressor.

(But, I always did like AE for renders better than fcp. )

That is, if your suggesting, importing my FCP timeline into AE, and exporting it from there.
I think Boris has a plugin which allows one to do that.
Because I don't think you mean exporting 720p from fcp, and then re-rendering it through AE?

I tell you what I did do, I ran tests with Compressors anti-aliasing slider @ "0," "20," "40," "60," "80" and yes, "100!" encoded them separately, and muxed them together in DVDSP to loop continuously, (with title cards for each.) And, I didn't see any, let me be clearer. ANY, reduction in the moire pattern. That anti-aliasing takes forever for Compressor to encode, even with a short test.

I guess it is just the nature of such a pattern. When you reduce it, the compressor, just doesn't know how to deal with all those horizontal lines crushing into eachother!