Interleave - what is it?

DelCallo wrote on 5/8/2005, 1:34 AM

Took some footage of my dog - she's jumping around all over the place. That captured footage (shutter speed 1/10000) looked a bit jittery, especially as I panned to follow the dog.

I noticed that, if I set under the Render --> Custom dialog interleave to either unchecked, or checked and set to lnterleave every frame, the jitters disappear.

So, my question is - what is it? Interleave, that is. What does it do when checked, when not checked, when set to interleave x number of frames?

Thanks.

Caruso

Comments

farss wrote on 5/8/2005, 2:02 AM

The manual does describe what interleaving does.

High shutter speeds do give fast motion a stobe look, it's used a lot down here for sports coverage, I think the reasons are to get better SloMo and also for webcasting at lower frame rates but that's just a guess.
Bob.

DelCallo wrote on 5/8/2005, 4:30 AM

Faars:
I did a search of the index on the term "interleave" (several searches), and didn't find anything. I'd like to read what the manual has to say. How do I find it?

Also, if turning it off improves the look of my video, what reason would I have to turn it on? I assum that Interleave is not the same as Interlace, right?

As always, thanks for the response.

Caruso

farss wrote on 5/8/2005, 5:30 AM

I searched the Vegas 6 manual, sorry but for some reason I cannot copy and paste it here. Basically all it controls is the interleaving of the audio and video blocks in an AVI file. The manual says turing it ON makes the avi file easier to play (I guess the player has to buffer less data). It will not have any effect that I can deduce once it's printed to tape or encoded for DVD. It should have no effect on the quality of the video, it might affect how a PC based player plays it out.

Bob.

johnmeyer wrote on 5/8/2005, 8:33 AM

farss is correct: it controls how the audio is interleaved with the video. I doubt that this setting had anything to do with your video looking better. What is really going on, I think, is that by making a change, you forced Vegas to resample the video and re-render it. This may smooth out the jerky quality that you get when you use the high "shutter speed" on video cameras. My guess is that you would get the same result by enabling "force resample" for the video event in question.

DelCallo wrote on 5/8/2005, 11:23 AM

Thanks for the replies.
I haven't actually printed any of this "better" footage to tape or rendered to DVD. We'll see what sort of result I get when I've had an opportunity to actually output some of this footage.

I have also experimented with forced resample, and it seems to help quite a lot, also. Thanks again.

Caruso

Liam_Vegas wrote on 5/8/2005, 2:41 PM

If this is for eventual display on a TV.. and you are looking at this on a PC screen... that may be your issue. You really do need to verify such video on an external TV monitor before you make any drastic changes to your project/rendering settings. The PC monitor is progressive and therefore you will not really get to understand what the interlaced video will look like.

DelCallo wrote on 5/10/2005, 1:45 AM

Thanks, Liam. I just finished working on footage from one of three cams on a shoot, and can verify that results displayed on my computer screen are a far cry (better) as compared with the output to a TV.

What to do, what to do??

Caruso

farss wrote on 5/10/2005, 6:43 AM

I think before anyone can offer any useful advice you need to qualify 'better'. What looked 'better'?
Images always look better on a smaller screen BTW, it's very hard to judge image quality when it's only small.
Also there's a few things that are very different between LCD displays and the CRTs in TVs, they'll affect how the effects of using fast shutter speeds appear.
Bob.