force_original_aspect_ratio
пропорции;ffmpeg -framerate 1/10 -i img%3d.png -i audio.wav \
-vf 'scale=3840:2880:force_original_aspect_ratio=decrease,pad=3840:2880:(ow-iw)/2:(oh-ih)/2,setsar=1' \
-c:v libx264 -crf 14 -r 25 -pix_fmt yuv420p -shortest output.mp4
via