View Full Version : Vegas problem with Slow motions AGAIN!


Miguel Lopez
December 8th, 2006, 10:26 AM
I´ve been experiencing a problem with Vegas 6 and 7 for the last year. Everytime i use slow motion from an interlaced footage, the rendered video results in a flickering video that cannot be used. Sometimes it is not very obvious (fro example in Similo), but sometimes it is a huge problem:

www.macgregor.autoecstasy.com/flicker_vegas_problem.mov

Check this file. That is unaceptable. I cannot work with this.
It does not matter if the video source is HDV or DV. Same problem appears. Upper or lower field does not affect this. I have tried everything without success.

I am working in PAL which means 50i. But i have heard the same problem also applies to 60i (can anyone confirm this?).

Anyone found a solution? Is it a Vegas bug unsolved?

Richard Alvarez
December 8th, 2006, 12:01 PM
I've only played with Vegas once, so I'm not very familiar with it. Is there an "interpolation" setting for your slow mo choices? In AVID, you can chose to interpolate between frames, so it's much smoother. No flicker at all. Is there a choice like this in Vegas?

Don Bloom
December 8th, 2006, 12:17 PM
I have to admit I've never seen that before in my time with Vegas and I do a fair amount of work with slomo so I really don't think it's a bug in the program.
Just out of curiousity what method did you use for the slomotion? Velocity envelope, playback rate, cntl stretch, a plugin? Also how much did you slow it down? To what percentage?
A bit more info and we might be able to figure this out.

BTW, has this happened before on other footage or is this the first time?
never mind-just reread the post and it seems like this has happened before.
Don

Miguel Lopez
December 8th, 2006, 01:10 PM
The problem is more evident when slowing down to 50%. From 50i you go to 25p.

Emre Safak
December 8th, 2006, 01:13 PM
Correct me if I am mistaken, but does Vegas even do interpolation? I think you need to get a proper time remapping plug-in for AE to do that.

Don Bloom
December 8th, 2006, 02:14 PM
I'm just guessin' here but what if you take the clip and go into the PROPERTIES of it and change the field order to PROGRESSIVE?
Just thinkin out loud.

Don

Brian Mitchell Warshawsky
December 11th, 2006, 09:47 AM
It looks like something else is going on here, almost as if there is a difference mask or similar effect being applied to the sky.

Looking at it frame by frame, the bright sky shots appear to be masked at the tree level.

Are there any effects being added to the track or sequence?

Just to confirm: The footage is properly set up to go from PAL to PAL?

Does the same thing happen if you render uncompressed or using other codecs?

Brian

Miguel Lopez
December 11th, 2006, 09:52 AM
It appears in the timeline and in any rendered format. It is not a problem of compression, it is in Vegas interpolation i think.

I think anyone is getting this same result, but most of the time the effect is very subtle, so only a very trained eye can spot it.

Here is the veg file, as you can see, i have tweaked the curves so the effect is even more noticeable. You can remove them if you want, the problem will still be there:

www.macgregor.autoecstasy.com/slowproblem.veg

Properties. http://www.film-it.net/stuff/macgregors_settings.jpg

The footage is captured either by firewire as DV or HDV.

It happens with any camera:
XL2, dvx100, sony FX, canon HDV.

It happens with Vegas 6 and 7 ( i cannot talk about 5 since that is too old).

It happens in any PC (and i have tried MANY).

I am quite good with Vegas if not an expert (sorry to speal arrogant, but dont think i am new with this).

Anyone working in PAL, maybe you can upload some interlaced footage in dv or m2t, something small around 6 secons will be enough. And I will show you the flicker.

Miguel Lopez
December 11th, 2006, 01:15 PM
YESSSSS, minutes ago VEGAS 7.0c was released. And they have fixed the bug!!!! The problem does not appear now!!!!!!!!!!!!!!!!! A miracle!

Jamey Johnson
December 11th, 2006, 04:20 PM
hahaha- good for you! Now post some more of those beautiful videos ;)

Peter Jefferson
December 12th, 2006, 06:08 AM
hmm.. V6 has this issue with slowmo'd footage but its only when the clip itself has peaked the 255 highlight threshold. If a clip blows out, or peaks beyond the saef level, this flickering is evident... ive had this issue ruin perfectly good deliberatly blow out.. in turn, ive had to bring the levels down, run my slowmo, render, then brin gthose levels back up after rendering..

will be checkin out V7 soon.

Brian Mitchell Warshawsky
December 12th, 2006, 08:38 AM
So could this be a bug that's been brought forward from every iteration of Vegas?

Miguel Lopez
December 12th, 2006, 08:41 AM
It could be.

However, i am trying the new slow motion (which is the same but without the flickering bug) and still there is some flickering, but in a different way.

The original flicker affected only the luminance.
Now it is more about artifacting, so i am triyng to understand where this comes: HDV compression? 4:2:0 color sampling.

I am going to compare against Premiere Pro2, to see what results i get there.

Brian Mitchell Warshawsky
December 12th, 2006, 09:19 AM
In addition to PPro, it may be worth trying this in Virtualdub (open source download) as well.

Vdub also allows you to export to 23.976.

I'm wondering if there would be any improvement in exporting individual frames from the Vegas timeline - once slowed down, and then importing into Vdub for rendering.

Brian

Miguel Lopez
December 12th, 2006, 09:21 AM
Ok, i cant make a proper slow motion in premiere from hdv footage at 50i. With premiere 6.5 i knew how to make it. Not now. :(

Andy Gordon
January 4th, 2007, 09:13 PM
I run into the flickering all the time with vegas 6, slowing 50i to 50% and rendering to 25p. The only way I could get rid of it was to alternate frames of deinterlaced video, so I had rendered the clip with interpolate deinterlace once as lower first, once as upper first then alternated the frames by masking one track with solid white every other frame. Only took about 5 mins to set up cos you can cut and paste blocks of the single white frames for the mask.