N png -> mp4

ffmpeg -r 30 -i "img%02d.png" -pix_fmt yuv420p -movflags +faststart perfectloop.mp4

trim first 5 second

ffmpeg -ss 00:00:05 -t 00:00:10 -i 1.mov 2.mov

webm -> mp4

ffmpeg -i capture.webm -vcodec libx264 -pix_fmt yuv420p -strict -2 -acodec aac capture.mp4

first frame

ffmpeg -i capture.webm -vframes 1 capture.jpg

webm -> gif

ffmpeg -y -i capture.webm -vf palettegen palette.png
ffmpeg -y -i capture.webm -i palette.png -filter_complex paletteuse -r 10 capture.gif

mov -> mp4

ffmpeg -i 1.mov -vcodec h264 -acodec mp2 1.mp4

trim video

ffmpeg -i 1.mp4 -ss 00:00:01 -t 00:00:08 -async 1 2.mp4