How to stretch time without affecting the fps

Hello, i’m new to natron. so many things i don’t know yet.

i want to achieve a simple task (this is simple in video editor program), but i don’t know how to do it easily in natron. Let’s say i have 200 frames, 50 fps, i want to stretch that 4 seconds clip to become 15 seconds with the same 50 fps. I have lots and lots of keyframes, moving one by one would be a tedious tasks.
If I just lower the fps, which is 13 fps it looks so ugly.

thanks for the help.

This can be accomplished with Natron’s “Retime” node. Keep your project frame-rate at 50 and place a retime node below your read node with the footage you want to retime. You’ll have to do a little bit of math to determine the speed value based on how many frames you want it to output. You should also set your project settings to the amount of frames you’ll be outputting so you can see them all on the timeline, in your example it is 750 frames which is 3.75x more than the input amount of frames.

Note that Natron’s retime node doesn’t do anything fancy to interpolate frames, it will just duplicate, ignore, or filter them as desired depending on the Filter option selected. In other software you may have options for optical flow retiming or adding motion blur to retimed sequences using motion vectors which can sometimes generate better results.

If you’re also doing some VFX work on this footage I would recommend doing the actual retime last and working on the source footage to minimize problems that come with retime artifacts.

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ok… thankyouuu… I got it working