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.mp4Input jpg. Output mp4.
I’m aware of the ffmpeg bug #4298. The posted suggested workaround is to use the
scalefilter prior tozoompan. 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
Solution:
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.mp4Basically, 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.