Create 30fps time-lapse video from 30fps source with frame interpolation

Question

I'm trying to convert video source to time-lapse using this method:

ffmpeg -i source.mp4 -an -filter:v "setpts=PTS/360" timelapse.mp4

but I don't like this choppy and jumpy output video due dropping frames with PTS/360 option. I've tried to use tblend=average,framestep=2,setpts=PTS/360 but it looks the same and doublicating this filter like

tblend=average,framestep=2,tblend=average,framestep=2,tblend=average,framestep=2,...setpts=PTS/180

doesn't make any visible difference for me.

Is there any other options with ffmpeg to blend 30 frames to 1 averaged frame and compile output 30fps video using these frames?

Answer 1

I've figured it out! I was wrong in calculations, so, correct command for x256 slowdown video with frame averaging will be like this:

ffmpeg -y -i source.mp4 -an -vf "tblend=average,framestep=2,tblend=average,framestep=2,tblend=average,framestep=2,tblend=average,framestep=2,tblend=average,framestep=2,tblend=average,framestep=2,tblend=average,framestep=2,tblend=average,framestep=2,setpts=PTS/256" -timelapse.mp4