Can't get a PNG pic to move smoothly!

dornier wrote on 6/20/2006, 6:03 AM

Ok, so I know Vegas likes PNGs right?

I also know you shouldn't go cramming a boatload of large pngs and expect vegas to smoothly handle it all.

I've got a flash transition at the front of a picture that just zooms out. It's only 2mb and I just can't get the thing to stabilize. It lags all over. The others, treated the same way, are just fine.

FWIW, I batch converted them from jpg to png using Irfanview. It ran them up in size quite a bit, but all the other pics move and transition very smoothly.

I've seen this before a few times--one pic just refuses to cooperate.

Comments

Chienworks wrote on 6/20/2006, 6:28 AM

Try the original JPG image instead. The whole "Vegas likes PNG better" is way overblown. And, considering the original was already JPG you gain nothing by converting it to another compressed format.

Can you explain a little more clearly "lags all over"? And, do you mean that you have a flash transition happening that you don't want? Or are you saying that you are adding a flash transition that isn't working? If the latter, are you using that transition on the other pictures too?

Check your keyframes. You may have an extra keyframe lurking, or you may have the smoothness values set differently for that picture.

dornier wrote on 6/20/2006, 7:14 AM

I've used the transition a few other times in the project.

It's a flash transition with the pic keyframed to start large and then end at a reduced size. (falling away). It skips during the flash, but more during the "fall".

I backed up those original photos. Would it be easier on Vegas to go back and put the original JPGs back in?

95% of them were either digital or prescanned and did require touchups. I could just leave them as jpg and not loose quality? I'm confused.

What's a good minimum size for an image that may only be enlarge during the project by about 5%? just enough to give some motion....

It seems that pngs slow down my preview window too. I've had larger jpgs not affect that in the past.

Chienworks wrote on 6/20/2006, 8:02 AM

"I batch converted them from jpg to png using Irfanview."

That made me think that your .png versions were identical copies of the .jpg versions. If that's the case then there is no reason to convert them. .jpg works just as well as .png. However, you now seem to indicate that you have done some additional touchups after the conversion, which changes things. .png does have the advantage in that there isn't any additional generation loss with each save, so in that respect .png is better than working with .jpg. That doesn't have anything to do with Vegas though.

In my experience Vegas seems to handle .jpg just as efficiently as .png. It has also been reported that a slight color shift is introduced by Vegas when rendering .png files, though i hasten to add that i've never noticed it. What is more important is to do as little processing with compressed formats as possible. Don't convert an image from .jpg to .png just to have it as .png (or any other format, for that matter). If, on the other hand, you need to edit an image then save it as a different format then that is fine as you are resaving for a useful purpose. Note that saving as .png won't be any better than the original picture; it just won't be any worse. Saving as a new .jpg file will lose some quality, but if you compress less more quality will be retained.

What's the right size for an image which will be enlarged 5%? Just add 5% to the video frame size and you have your answer. If you're working with NTSC SD material the frame size is 654.55x480. 5% larger would be 687.27x504.

dornier wrote on 6/20/2006, 8:48 AM

Thank you very much for the guidance.

I might go back in and put those original jpegs in there for space's sake.

(except for the modded ones)

btw, is there a difference to be seen using the 'reduce interlace flicker' in both vegas and DVDA at the same time? Or, does DVDA have it in the event you rendered/encoded in a different NLE app?

Just curious.