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I have a video that has been recorded at 7 FPS. I noticed that in the Windows properties of the video file, it is tagged as 25 FPS, and I see that the recorder has inserted each second fake frames (copies of the 7 frames shot in beetween these 7 images) to reach 25 FPS in the recorded video file.

I'd like to convert it to a real 30 FPS video, without changing its duration, letting the software create missing images or replacing fake static ones (with newly interpolated images) to have a smoother play, even if it's not as perfect as what I could obtain with a native 25 FPS record.

For a quick try, I have tried to put 2 effects one after the other, one to accelerate the video at 300%, to make the fake images disapear, and another to reduce the speed at 33%, to force the soft to create interpolated images, all of this in a 25 FPS (for a try at 25) composition in AE, with no success.

Do you know how I can do this ? All tutorials I find on the Web talks about accelerating or reducing speed for slow motion, but for my own I want to keep the speed, just make the whole thing smoother.

  • It really doesn't matter if it's 7fps in 30fps? You don't want to calculate the motion of the frames in between, right? – p2or May 18 '15 at 22:06
  • @poor:I want the software to generate a 30 FPS video file in wich the key files are each of images taken at 7 FPS (real footage), and insert in beetween new interpolated images. – Oliver May 18 '15 at 22:27
  • You have a 25 fps video which just contains repeats of frames captured at 7 fps, right? No interpolated frames? How long is the piece? What codec and container? – Jim Mack May 19 '15 at 0:09
  • @JimMack:yes that's it. It's an AVI container of near 20 secs (for testing, but I have other ones that are longer like 2 min or more), uncompressed YUV as far as I know – Oliver May 19 '15 at 0:17
  • @Oliver So 7fps represents real time, and you want the resulting video to also represent real time, but at 30fps. In that case you need to generate intermediate (interpolated) frames that don't currently exist, not repeat frames that do exist, is that right? – Jim Mack May 19 '15 at 2:23
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I can't give you specific commands but since these are fairly short I'd extract the individual frames into a TIFF stack (or similar), then import them at the correct (7fps) frame rate into your editor. Then I would apply twixtor or an open-source equivalent to raise the frame rate. How well those work depends somewhat on the amount of motion. 7 fps to 30 fps is asking a lot.

You may find ffmpeg / avconv assistance in extracting only the frames that are actually different -- that is, removing the extra inserted duplicate frames.

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