Skip to main content
Participant
April 23, 2018
Question

[Help] Motion Artifacts (Optical Flow?)

  • April 23, 2018
  • 5 replies
  • 3940 views

Hello,

trying to screencapture disneys Alice in wonderland, i came across these motion artifacts.

The Source file is:

  MPEG-4-Film

  2.162.839.575 Byte

  1424 × 1080

  H.264, AAC

  01:15:16

Frame 1 is pure

frame 2 has optical flow (?)

frame 3 is pure

frame 2 is split into layers (?) though. One that is drawn by hand and digitalized, and one that is the optical flow.

Is this a Bluray specific thing? Is there a way to turn that off?

As i need to print out single frames, it is somehow unacceptable for this to occur.

Please help,

best regards

vj

This topic has been closed for replies.

5 replies

Menoal1Author
Participant
April 25, 2018

Thank you for your replys.

FFmpeg looks kind of complicated but i will try.

I turned all the frame blending off. My settings look like this now.

   The effect is still there. Could it be that my source file is a recording of a bluray that was recorded with

   frame blending on. So now the artifacts are in the file, not effectable anymore?

chrisw44157881
Inspiring
April 25, 2018

mediainfo program should tell you if its 3:2 pulldown.

angie_taylor
Legend
April 23, 2018

If you have retimed footage Premiere Pro will apply frame blending to try to interpolate using either a frame mix or optical flow. If you don’t want this to happen it can be switched off so you only have the original frames repeated. To do this, right-click on the clip and choose Speed/ Duration. In here you can switch off frame blending. Hope this helps.

Menoal1Author
Participant
April 23, 2018

I think i did not state that clearly in my OP.

What I need is to know if there is a possibility to not use,

to avoid, any optical flow or whatsoever, so that i just stay

with the pure digitalized hand drawn frames

(that have to come from blu-ray for the good resolution).

The problem is, that most of the frames i need to capture,

never stay without optical flow effects because the scene

is just very fast moving.

imDMl5MVy2IecQV4efKrKY8_M9hYBmXD7srQ3LEjFrI.jpg?w=1012&s=8c5fd1ed8660b62f634d93dd5543457f

carlosz13485882

Is it possible to deinstall any all of these functions?

Graeme Bull

is there a forum you know i could ask in?

chrisw44157881
Inspiring
April 23, 2018

whow there, back up the truck. is the original video 3:2 pulldown, ie. are you trying to capture from a bluray? is it true 23.976 progressive frames? is it 12fps? why are you trying to interpolate frames in the first place? are you trying to export at a different frame frame than the original image? why are you using screencapture in the first place? the data is usually stored in a particular file format like mpeg2 or h.264.

and finally,

since most animated films were cell painted at 12fps, I don't think any optical flow is going to work at that low of a framerate, except possibly alchemist od, and even then, I highly doubt it. there's just not enough motion information.

Community Expert
April 23, 2018

Optical Flow on Premiere Pro, like other effects as Motion Tracking on After Effects, require the highest amount of data

and detail to work properly and interpret the pixels of each frame. So it works best with native un-encoded footage

than it does with encoded (compressed) footage, because of loss of data an detail, resulting in such artifacts, those are

pixels not analysed or interpreted correctly. Try with native high resolution video files and check if you get such artifacts.

I tried on an encoded footage, I got artifacts... Tried on original video files shot at 1920x1080 it worked good.

Graeme Bull
Community Expert
Community Expert
April 23, 2018

This is hardly a Premiere Pro problem I would think. Either way though, it's likely from the encoding, not decoding.