interlace question

[mohsen123]

hi there .
I want to have a interlace animation . I worked my animation in AS animation fixed with a music and now I want to make it interlace I search the forum for a solution I find :<export animation in 50 fps and make it 25 in other apps> ?
when I worked this in fusion and export my interlace I see my animations in half of time that I was worked in AS . I fix them in AS by music and when I interlace them they are so fast and...
I think its because when I export at 50 fps in bmp files , the bmp files is same 25fps export . and when I convert them to 25 time is half ...
can you help ?
t h a n x

[slowtiger]

That's not the proper way to do.

In general, you'll export animation from AS (or any other program) in full frames, either as a video file or as an image sequence. This is called "progressive" although the term makes no sense with images files: they are always progressive.

Your video editing program takes care about that annoying interlace problem while exporting. You don't have to care about that as long as you feed the editor progressive files.

You have to know your target fps setting. For TV it can be either 25 fps or 30 fps (29,something). Ideally this will be the fps setting you use in your AS project, especially if you have to sync to music.

[dm]

If I understand you, you want to do your interlace in Fusion (compositing application)?

The 50 FPS to 25 FPS thing is a frame per field interlace. Your project in AS needs to be 50 FPS (project settings), export the image sequence at 50.

In Fusion, interlace, and be sure you choose proper field dominance (odd/even). Output at 25 FPS in whatever format you need (Quicktime, AVI, whatever). You might need to apply a time adjust in Fusion as well.

What the 50 to 25 thing does is give you a smoother interlace, and cleaner frame to frame motion.

For the most part, you're better off following Slowtiger's suggestion of letting your editing software deal with the interlace (at 25 FPS). Fusion can do that as well. 25 in, add interlace, 25 out (PAL). If someone doesn't do it first, I'll try to post some better info on this later (like maybe tomorrow later)

[Rhoel]

The 50 > 25 is in fact 50 fields per second to 25 frames per second. Programs like Fusion (been over 7 years since I used that last) and Combustion can split/recombine fields for matting and other field specific tasks.

The technique of doubling the time then combining as interlace is only justified in a few rare cases. If its to avoid stobing, RealMotionBlur is a better solution.

Most edit suites can handle progress images - using progressive gives better quality and removed the problem of D1/DV odd/even even/odd interlace issues: Again, the edit suite output settings means you don't have to worry if its the right way around.

Other issue - BMP files are huge ... I usually use PNG for output and have had no quality/artifact problems to date. The file sizes by comparison are tiny.

Rhoel

[mkelley]

Yeah, just to try and clear this up, DM is wrong. Outputting 50fps from AS won't buy you a thing.

There are animation programs on the market that WILL output interlaced frames, and what this essentially means is the action is "blurred" in between each frame (it's a little more complicated than that but let's keep it simple right now). AS won't do this -- the only blurring it does is not related to motion thus there is absolutely NO WAY you can achieve an interlaced look to anything that comes from AS.

As ST says, the output from AS is progressive video -- which is just another way of saying there isn't any interlacing going on. If you are working on a project that combines interlaced video with AS it will look a little odd -- the AS parts will not combine the same way and there really isn't any way around it (even bringing the video INTO AS won't solve this, as the animation in AS still is only progressive).

Your best bet is to just avoid interlacing completely. If you have interlaced video, convert it to progressive. Interlacing is actually a thing of the past, and is slowly disappearing even in the NTSC world (any film shown on television, for example, is progressive since that's how they are filmed).

[dm]

Yeah, just to try and clear this up, DM is wrong. Outputting 50fps from AS won't buy you a thing.
...
Interlacing is actually a thing of the past, and is slowly disappearing even in the NTSC world (any film shown on television, for example, is progressive since that's how they are filmed).

Wrong about what?

Try reading my post again (the whole thing, if you can manage it).

If you have an older TV, you have interlace. A film broadcast for TV (non-HD, non digital), is interlaced. It's also got 'pulldown' added if it's NTSC (incredible as it may seem, 24 progressive frames don't exactly fit into 29.97 video frames-which get broken into fields anyway). Films aren't projected for broadcast. They're generally transferred to videotape first.

Is this getting confusing now?

[heyvern]

How come I never have to worry about interlacing when burning to DVD video or to video tape? I've been doing some sort of this for a long time. First recording to VHS than later to a digital camera and now directly to DVD.

In all that time I never had to render my source animation files to anything but the target FPS, 29.97 or 30fps. To be honest I always used the default video software settings like in Premier or AE usually I think I just went with 30fps. Now with iMovie and other types of "automated" DVD authoring tools I just load the videos and burn to DVD. Haven't had a single problem. iMovie does its "magic" conversion to HD.

Should I consider rendering to 60fps and "interlacing"? Is there a boost to the quality that I've never noticed before? If I had to start rendering everything to 60fps I would be very sad.

-vern

[mohsen123]

thanx all for replay's

The 50 FPS to 25 FPS thing is a frame per field interlace. Your project in AS needs to be 50 FPS (project settings), export the image sequence at 50.

I do that !

In Fusion, interlace, and be sure you choose proper field dominance (odd/even). Output at 25 FPS in whatever format you need (Quicktime, AVI, whatever). You might need to apply a time adjust in Fusion as well.

I cant Understand 1thing !!!!
you say that in fusion make 50fps sequence to 25 fps hum ?
it means that I export 2second make> 1second ?
but I animate my animation fixed by a music in AS in 25fps ? when I export 10 frames from AS in 25fps and 50fps in both there is 10bmp sequenced .
so when I export in 50 (or 500!) there is 10 frames exported and when interlace them[in fusion]
<example>4seconds animation will export 2seconds ! so I never can Fix it again to music !!!



I have small small time . I have 15GB bmps [animated in AS in 24 fps > exported sequence in 50fps] I must finish them in this week !
is there any quick solution ? is a fusion motionblur good solution to finish them? is there another quick software ?

heyvern
dont you have any problem in your final DVD ?
isent there any little shake in motions ?

[heyvern]

heyvern
dont you have any problem in your final DVD ?
isent there any little shake in motions ?

No, it looks the same as when I watch it on the computer at 30fps. I never see any difference. I export from AS at 30fps with sound, burn to DVD... everything just fine.

-vern

[slowtiger]

"Interlacing" is a trick which only is used for broadcasting purposes in old analogue TV sets. It does not apply in DVDs or video files on computers.

Video editing software still has the ability to import and export interlaced material and even tinker around half images (even/odd frames) because video editors often have to deal with broadcasting material in its original format.

You, as an animator, should not bother about this. You set your project to 25 fps and animate in sync to your music, then you export exactly 25 images per second (BMP or PNG or whatever format your video editor will accept).

"Interlacing" doesn't make your animation better.

[mohsen123]

so this mistake will be a good experiment to me!
so I think my best way is what I was test . add some motionblure in fusion ?

[slowtiger]

Motion blur? Do you have such fast animation that this is necessary? Normally you don't need this. If you need it, only apply it to the few scenes which really need it.

[dm]

so this mistake will be a good experiment to me!
so I think my best way is what I was test . add some motionblure in fusion ?

mohsen123

i think the point here is that you don't need to worry about any of this. just get your animation out at 25 fps, and you're done.

Actually, what is it that you want to do with the final animation? That's probably the better way to get your issues cleared up.

[dm]

How come I never have to worry about interlacing when burning to DVD video or to video tape? I've been doing some sort of this for a long time. First recording to VHS than later to a digital camera and now directly to DVD.

The machine and/or software take care of interlace for you. Many video codecs are still interlaced (done on encode). VHS interlaces as it's recording. Here's an article on DVD's and interlacing and stuff like that: http://www.hometheaterhifi.com/volume_7 ... -2000.html

Should I consider rendering to 60fps and "interlacing"? Is there a boost to the quality that I've never noticed before? If I had to start rendering everything to 60fps I would be very sad.

No. don't bother. That 60>30 / 50>25 thing is essentially 'frame blending'. It's of little value to most mortals.

You're on a Mac. Put in a DVD, and in the DVD player: View menu has deinterlace options. Progressive scan in a DVD is pretty common now. No deinterlacing needed. There's a flag set on the DVD telling the player how it can deal with it. If you shove an old, interlaced DVD into your computer, and turn off the deinterlace function, you can still see the scan lines.

Interlace degrades quality, if anything. It was just a way to deal with the technology available when they first started making TVs. Basically ends up with lower bandwidth requirements to interlace. (also 'takes advantage' of the sine wave of AC electricity).

Everything would have probably been better if I had just 'kept my mouth shut' in the first place. Slowtiger pretty much took care of the initial question, succinctly. Sorry about the additional information.

Oh, I forgot. How in the world do you choose an export frame rate when you're exporting an image sequence? I thought it just spit out however many frames there were in the project (regardless of frame rate).

[mkelley]

DM,

You were wrong when you said interlacing leads to cleaner frame to frame motion. It does nothing of the kind -- indeed, among professional effects folks it's well known to avoid interlacing and use motion blur instead (I well remember Spielberg's crew debating this with folks from the Lucas ranch during the "Close Encounters" post). That's all I was really reacting to (I was part of those debates on the 3D pro forums and it was interesting for the effects folks to see the light, as it were :>).

But you're right, it does degrade quality and that's now why no effects shop will use it -- however, we still have to deal with it until video footage stops getting done with interlacing turned on (I note now that my new tiny HD camcorder allows me to shoot progressive, but it's not the default :<(