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-   -   Flickering in JPG video montage (https://www.dvinfo.net/forum/what-happens-vegas/129309-flickering-jpg-video-montage.html)

Donald Blake September 3rd, 2008 07:22 PM

Flickering in JPG video montage
 
Hey everyone, here's my problem.

In vegas when I add many JPG pictures from an SLR camera (2592 x 3872) Whatever the rendered file avi, mpg or wmf either HD or SD there's always a sort of flickering, waving or distortion in the rendered video (I dont know what to call it) Also the images aren't as crisp and clear as they originaly were. I have tried everything but didn't find the right answer yet.

Here's 1 of the 3 montage I made with the JPGs on youtube, but i guess the compression from youtube exagerates the problem but still gives you a good idea of the problem itself, you can clearly see it on the first image (after the intro).

YouTube - 2e Montage photos @ video de Evy Productions

thanks!

Mike Kujbida September 3rd, 2008 07:38 PM

#1: Unless you're doing deep zooms, reduce the size of the images to no more than twice your project size (i.e. 1440 x 960 for SD NTSC).
#2: The first image appears to be very high in contrast. I always apply the Secondary Color Corrector FX (use the Computer RGB to Studio RGB preset) to all stills in any project I do. This reduces the brightness range from 0-255 down to 16-235 which Vegas likes much better.
#3: Apply Reduce Interlace Flicker to all still photos.
#4: If it still flickers, try a very light Gaussian Blur FX on the affected image(s), 0.001 to 0.003, in the Vertical direction only.

Graham Bernard September 3rd, 2008 11:57 PM

Mike? Why just add GB in the vertical direction only? Always willing to learn.

Grazie

Jeff Harper September 4th, 2008 02:23 AM

In addition to resizing as Mike suggests, I convert jpgs to png, which seems to help a tad as well.

Tony Spring September 4th, 2008 03:44 AM

If you're rendering to interlaced try progressive instead. That's how we render our photo montages.

Mike Kujbida September 4th, 2008 04:26 AM

Quote:

Originally Posted by Graham Bernard (Post 929060)
Mike? Why just add GB in the vertical direction only? Always willing to learn.

Grazie, here's what Bob Grant (aka farss) had to say about GB in a thread called v7 and images flicker on the Sony Vegas forum. Over the years, I've learned to trust what Bob says about a lot of things and this is definitely one of them.


The Gaussian Blur FX allows you to control the amount of blur in the vertical and horizontal direction. The idea is to filter out enough of the high frequencies from the image to prevent aliasing. The main source of the problem is in the vertical resolution, with interlaced video the vertical resolution should not exceed half the number of lines and that is easy enough to exceed coming from a high resolution still.

So you want to reduce the vertical resolution and do no harm to the horizontal. In the GB FX set Vertical to 0.001 to 0.003, leave horizontal at 0. The exact amount of vertical blur you best judge on a case by case basis while watching on an interlaced monitor.

The advantage of applying the blur before downscaling is it's the downscaling itself that introduces the problem. Reducing the blur (lowering the resolution) before the downscale gives you better control i.e. you'll need less blur (less loss of resolution) to stop the aliasing.

Note that watching the video on a progressive scan device you'll not see this problem. Note also it's impossible to prevent all aliasing kind of artifacts in video. Moire is unavoidable, that's why they used to watch what people were wearing in front of the camera.

Donald Blake September 12th, 2008 08:31 AM

Ok thanks everyone for your advice,

So far i've tried everything exactly as you guys told me ;

Mike : #1 i am doing deep zooms so i cant downconvert my file but i've tried it with a smaller file (half resolution) / #2 (RGB) i did it / #3 (RIF) i did it / #4 (GB) i did it.

Jeff : i converted to PNG

Tony : rendering my file as an AVI (Video: 23,976 fps inserting 2-3 pulldown, 720x480; Progressive. Pixel Aspect Ratio: 1,212. OpenDML compatible.)

After i've done all these things here's what i noticed, The result is that it has reduced the flickering by maybe 40%, but it still there, it's hard to describe but it's like when your holding up something very heavy in a still position, after a while when your muscles are tired they start twiching and shacking even tho they are still holding it in position, that's the kind of flickering my images make, haha weird description but like i said it's hard to explain since i can't show you guys the big AVI files themselves.

And the other thing is that when i add some of the FX like the Gaussian Blur (0.001) it changes the crisp clear looks of my pictures from my SLR camera wich is one important thing that gives quality to a project in my opinion.

Could it be that this is a bug in Vegas 7 ??? Did any of you guys manage to succesfully make a video montage with still pictures without them flickering at all ???

Jeff Harper September 12th, 2008 08:57 AM

You might need to downsize further...try Irfanview if you don't have it...amazing free program Download IrfanView
then batch resize your photos to no larger than 1K if you can work with that. I have Fireworks CS3 and Photoshop CS3, but nothing I've found is as fast and user friendly for batch resizing and converting as Irfanview...make sure to start with your original photos, not your newer versions...

Open Irvfanview, then choose "open" and find your folder with photos and "add all", and play with custom settings...

In Vegas select all your photos and right click and reduce interlace flicker if you haven't already, also try disable forced resample on each image.

let us know what happens...

Some flickering might be inevietable...keep your motion to a minimum if all of that doesn't produce satisfactory results, Though I notice that in your montage you are not doing drastic motion anyway.

Danny O'Neill September 12th, 2008 09:01 AM

I have never had this. I have used the standard PAL DV Widescreen or HDV 50i project templates and render using either a custom profile for Vimeo or DVD Architect PAL Widscreen profile.

Ths is using pictures catpured at 10mp so about 3000x2000 or something resolution, pretty high. All have the 'reduce interlace flicker' selected in the picture properties.

Jeff Harper September 12th, 2008 09:15 AM

I have absolutely no problem with most professionally shot photos, which I work with quite often. Until I starting converting all photos as I outlined, I did have issues with flickering, though. Lager files just didn't work well for me. When I reduce the size sufficiently, I will often even forget to "reduce Interlace flicker", and don't even notice it most of the time!

Blake, one more thing you can try if all else fails, render using "BEST" settings...it's recommended for jobs with lots of stills...I don't find the need to use it, but is supposedly can help!

Chad Ream September 13th, 2008 06:58 PM

Just jump in and reinforce what has already been saide. Resizing the image seems to help quite a bit when I run into these similar challenges.

Chad

Donald Blake September 24th, 2008 08:37 AM

Ok so i have resized my images, i've even went down to the exact same size as the SD screen (480 high) and dosen't seem to change much.

But i'm begining to think my PC is the problem, can it be that a P4 with an integrated video card (on board) can cause the problems?? I would love to see the same files on another PC... I think it would answer a lot of questions for me.

Jeff Harper September 24th, 2008 11:33 AM

I'm wondering if the issue might be with the original images....do an image search on the web, find some great, clear photos, and try a few of those images...see if the problem still exists...sounds frustrating.

Duane Adam September 24th, 2008 12:40 PM

I've noticed more aliasing with zooming compared to horizontal panning so now I just zoom less. Setting the playback rate in properties to 50% also seems to help reduce flickering.

Donald Blake September 26th, 2008 07:23 AM

haaa thanks guys for all your advice, and Jeff, your are right for one thing... it's very frustrating!

I've already tried with images from the web, I've also tried without zooming at all, and nothing seems to work, that flickering is still there everytime, Thanks anyways.


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