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I'm trying to create a basic 5 second zoompan to the center of an image (from the example on the ffmpeg.org website). The command below works, but jitters more than my hands after 5 cups of coffee:

ffmpeg -framerate 25 -loop 1 -i island.jpg -filter_complex "[0:v]scale=-2:480,zoompan=z='min(zoom+0.0015,1.5)':x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)':d=125,trim=duration=5[v]" -map "[v]" -y out.mp4

Input jpg. Output mp4.

I'm aware of the ffmpeg bug #4298. The posted suggested workaround is to use the scale filter prior to zoompan. But as shown in my example, this still seems to have no effect.

It seems any arbitrary x or y values cause the jiggle/jerky/shaky effect.

Can anyone offer any kind of effective workaround? Thanks!

Version info:

ffmpeg version 3.1.2-static http://johnvansickle.com/ffmpeg/  Copyright (c) 2000-2016 the FFmpeg developers
  built with gcc 5.4.0 (Debian 5.4.0-6) 20160609
Timbo White
  • 265

1 Answers1

21

Avoid downscaling beforehand. Either apply a trunc function to the x and y expressions. Or upscale it before. Preferably the latter. This gets rid of most of the jitter for me. 

ffmpeg -framerate 25 -loop 1 -i island.jpg -filter_complex "[0:v]scale=8000x4000,zoompan=z='min(zoom+0.0015,1.5)':x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)':d=125,trim=duration=5[v]" -map "[v]" -y out.mp4

Basically, the filter is rounding the values from the x and y expressions, which may be either rounded up or down. That's creating an uneven motion due to changes in direction of pan. Increasing the resolution beforehand allows the rounding to be smaller.

Gyan
  • 38,955