60fps looks slow

[wrightwriter]

Here is an example https://imgur.com/a/d3kRpva
ffmpeg 4.2.2
30 fps is correct speed

[bloerwald]

Can confirm. It appears the ffmpeg command line as well as the frame count is correct.

duration=8
fps=50

/opt/local/bin/ffmpeg -y -r 50 -f image2 -s 1280x720 -start_number 0 -i …export%03d.png -vframes 400 -c:v libx264 -crf 20 -pix_fmt yuv420p -shortest …export.mp4 -loglevel error
/opt/local/bin/ffmpeg -y -start_number 0 -i …export%03d.png -vframes 400 -vf fps=50,palettegen …export-palette.png -loglevel error
/opt/local/bin/ffmpeg -y -start_number 0 -i …export%03d.png -i …export-palette.png -lavfi 'fps=50 [x]; [x][1:v] paletteuse' -vframes 400 …export.gif -loglevel error

Comparing the exported frame pngs 0@50 = 0@25 and 1@25 = 2@50, as it should be. 1@50 also is somewhere in between, so the exported frames are also fine.

(ffmpeg 4.4.1 via macbrew)