Jumpy scene changes?

[Jesper]

Hi everyone,

I'm working on a project of directing a video, which uses material from other DVDs that have all been transferred from VHS.

On a lot of the scene changes the change between the two bits of footage is a little jumpy/flickering than I'm used to when watching other videos, either on the computer or TV. It's not very visible actually, but normally a scene change feels comfortable to the eye, and here, while not really a visible artifact the scene changes are very obvious, almost like one flicker.
I know this might sound strange, but I don't know how to describe it any better.

This is not on all scene changes, but on some.

All the footage I'm using is top-field-first according to GSpot. I'm exporting with upper field first as well, in Adobe Premiere Pro, which I use to direct. So, the obvious reason of incorrect field order is probably not the reason for this problem.

Does anyone know what causes this and how I can solve/prevent it?

Thanks in advance!
Jesper

[redwudz]

I rarely do that type of editing with MPEGs, but assuming both video clips are exactly the same formats and settings, it may be a problem with the frame you are cutting on. I work with mostly AVI and some formats like Divx are especially bad with a keyframe every 300 frames. Makes a very jumpy edit if you don't use a keyframe for a cut. Are you able to view your cut point area frame by frame? That might show you where the problem is if you can compare one of the problem cuts to one that works smoothly. With AVIs, I usually re-encode to smooth out bad cut points. But then I have quality loss.

I like DV for AVI editing as every frame is a keyframe. Makes it nice for editing.

But my MPEG editing knowledge is not very extensive. Maybe another member can give you some better information.

And welcome to our forums.

[guns1inger]

Are you editing them together in Premiere as a single clip ?
If so, are you just butting them up against each other, or doing a short (3 - 5 frame) cross fade ?
If you are not editing them, are you authoring each clip separately to play one after the other ?

Scenes (or chapters) on a DVD are not separate clips. A clip is a title that may contain many scenes. Scenes are navigation points in a title. DVD Players treat each differently. I have seen the effect you describe on discs where the person authoring has not understood the difference, and cut the title into separate, smaller titles, thinking these were scenes.

[Jesper]

I rarely do that type of editing with MPEGs, but assuming both video clips are exactly the same formats and settings, it may be a problem with the frame you are cutting on. I work with mostly AVI and some formats like Divx are especially bad with a keyframe every 300 frames. Makes a very jumpy edit if you don't use a keyframe for a cut. Are you able to view your cut point area frame by frame? That might show you where the problem is if you can compare one of the problem cuts to one that works smoothly. With AVIs, I usually re-encode to smooth out bad cut points. But then I have quality loss.

I like DV for AVI editing as every frame is a keyframe. Makes it nice for editing.

But my MPEG editing knowledge is not very extensive. Maybe another member can give you some better information.

And welcome to our forums.

Thanks, I'm going to check out some information about keyframes, and see if my settings have any keyframe options, which might be the cause.

Jesper

[Jesper]

Are you editing them together in Premiere as a single clip ?
If so, are you just butting them up against each other, or doing a short (3 - 5 frame) cross fade ?
If you are not editing them, are you authoring each clip separately to play one after the other ?

Scenes (or chapters) on a DVD are not separate clips. A clip is a title that may contain many scenes. Scenes are navigation points in a title. DVD Players treat each differently. I have seen the effect you describe on discs where the person authoring has not understood the difference, and cut the title into separate, smaller titles, thinking these were scenes.

Hi,

I'm editing them together to a single clip, without any cross fades, just the two bits against each other.

I haven't got to the authoring stage yet, sorry for the confusion of me using the word 'scenes', but I don't mean the chapters, but really the different shots which were edited together.

Thanks!
Jesper

[guns1inger]

Try doing a 3 - 5 frame cross fade to smooth out the jarring. Also, don't trust any software to tell you what the field order is. They all make mistakes. The best way to be sure is to eyeball the fields yourself.