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doubled frames in composition and renders
I’m having the same problem as this person:
https://forums.creativecow.net/readpost/2/892153https://forums.creativecow.net/readpost/2/892153
Frames seem to randomly double when previewing and rendering. When I double click on the clip in the bin and step through the player, there are no double frames, but every instance of the clip in a composition or render results in some frames being “sticky” (ie – 3 regular frames, then the same frame again, then 7 new frames, then a frame repeated. The sticky frames seem to be random. The result is like this, each frame being a number:
1 2 3 4 4 6 7 8 8 10 11 12 13 14 15 16 17 18 19 20 20 22
Please note the omission of frames 5, 9, and 21. Those frames, in preview and render, are simply not there, the previous frame is in its place.
I’ve disabled OpenGL, I’ve changed the secret cache settings, everything I can think of. I tried swapping out my RAM, didn’t work.
The footage is 23.98fps. I’ve tried making my comp 23.98fps, making them both 24fps. Nothing works.
The footage is Uncompressed 10-bit 4:2:2 23.98fps.
Any thoughts?
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12 Replies
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Follow-up:
Encountered something else very strange. Sometimes when I keyframe a layer’s position (roto’d footage moving across the screen), there seems to be a “hiccup” frame randomly in the interpolated motion. The layer contents will seem to freeze in its motion path for one frame. I thought it could be a motion interpolaton problem, but stepping through the actual position values shows a steady rate (ie, the position value goes steadily 1, 4, 7, 10, 13) but the clip will stay in the same position or just budge slightly in its motion path.
When there is a hiccup frame, the next frame seems to leap in motion, similar to the pattern I show in my previous post, where some frames are simply not being shown:
1 2 3 3 5 6 7 7 9This seems to suggest my problem is with the render and not with the video cadence interpolation.
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Another follow-up:
I tried to use another computer and had the exact same problem. It must be the footage.
Here’s what Quicktime has to say about the clips:
-Format: PNG, 720×486, Millions+
-Movie FPS: 23.98Here’s my AE sequence specs:
-720×384
-Frame Rate: 24Some more info:
The sticky frames are never more than 5 frames apart, here’s the exact order I’m getting:
1 2 2 4 4 6 6 8 9 9 11 11 13 13 15 16 16 18 19 19 21 22 23 24 24 26 -
As explained in the previous thread, this only occurs in After Effects when the clip is in a composition or rendering.
I’ve tried many different editing timebases. I dragged and dropped the footage into the bin. I’ve tried it on a PC and Mac.
The footage is 35mm telecine to Uncompressed 10-bit 4:2:2 24P currently working at 720×486. Some of the pieces are PNG codec. I’ve tried converting them to Animation and Uncompressed.
Is there something I’m not getting about bringing 24fps stuff into AE?
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If you need any more information, let me know.
I’ve offlined and onlined about 10 24P projects, buddy. This is the first time I’m working in After Effects with 23.98 footage.
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You’re absolutely incorrect, and you haven’t read what I’ve written.
720×486 is a frame resolution with no relationship to cadence or framerate other than often being grouped with 29.97 in a standard format we call NTSC.
Again, the problem only occurs when the clip is in a composition or render. I can watch it fine in AE.
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Well, that was fun.
Notes:
AE uses 23.976, FCP uses 23.98, for what it’s worth.Questions:
1. under what conditions (playback app, etc.) does the footage actually look correct? FCP? QT Player? (in addition to AE’s QT Player)
2. how was the footage shot? Is it stock? Do you trust the DP? Might it have been badly telecined?
3. did you try dropping the clip onto the “new project” button at the bottom of the comp window to ensure the comp has the same settings as the footage?
4. Did you remove pulldown by using the guess button, and if that didn’t work, trying all cadences?
5. You said the clip plays fine in AE. You might be using the QT Player that lies within AE? Did you try alt-double-clicking on the clip and stepping through using that viewer?
6. The clips should not say 23.98 in QT unless somebody tried to remove pulldown before the clip got to you. Is this the case?
7. Your AE sequence is 720×384. Is this correct? If so, why 384?You know, I think somebody dropped the 29.97 footage into a 24p FCP sequence, rendered it, then gave it to you without removing pulldown.
Anyway, please answer each question as best you can, and get back to us.
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The footage wasn’t recorded at 29.97, as I’ve already stated, it was a 35mm telecine straight to 24P (23.976).
In addition, there are many cameras that can record in a true 24 container, the HVX comes to mind, it has a direct-to-file recording format that has no blending or dummy frames. Proof is that it’s frames can be output into an image sequence that has 24 frames in each second. Additionally, I could’ve output from an animation tool at a perfect 24 fps.
Your information is about three years old, Dave. Why do you keep mentioning video cameras? Why do you keep mentioning what something was “recorded” at? I never said this was raw footage. I never said anything about a video camera.
In any case, I found the solution: convert all the 23.98 pieces to 23.976 and use a 23.976 composition. For whatever reason, no 23.98 piece I put into 3 AE versions on 3 comps works correctly, but the 23.976 pieces do. I thought there was no difference, but apparently there’s a major one in AE. I double checked some pieces I may have worked on in the past that were at 23.98, and I had none, odd. All were 23.976.
Using Quicktime conversion worked fine for me with the exception of one or two sticky frames at the head of all resulting clips (the 23.98 cadence seems to be giving Quicktime a touch of leftover trouble when it converts).
Converting to 24 fps gave worse results. Go figure.
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The solution was to convert all clips to 23.976. I used Quicktime. I still have a few sticky frames at the head of each clip leftover, but overall solved.
What happened was one VFX artist output from AE at 23.98 and should’ve used 23.976 or 24. Very weird. Outputting from FCP at the timelines’s “23.98” has a very different result.
Apparently either there is a major difference in cadence depending on what you’re exporting from or AE just plain can’t do 23.98.
Next time I’ll do my comps in good ol’ Vegas, where cadences run free and unrestrained.
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Hmm … interesting.
To my mind, this should have been the workflow for the team:
1. capture the telecine’d video at 29.97 fps into FCP or whatever NLE.
2. import that 29.97 footage into AE, removing pulldown in the interpretation. This will allow you to work with 23.976 footage in a 23.976 comp, which is 24P. -
By the way:
.8 x 30fps = 24fps
.8 x 29.97fps = 23.976fpsFCP’s 23.98 is a round-off — it really means 23.976. Don’t ever enter the value “23.98” into AE, because it will take you at your (inaccurate) word, and won’t think “he really means 23.976”. It will give you a 23.98fps timeline, which is wrong.
Oh, and when FCP says “field dominance” it really means “field order”, which is the correct term. Just had to get that in. 🙂 The difference between the two is left as an exercise for the student.
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