gif to video
ffmpeg -i dog.gif dog.mp4
add watermark
ffmpeg -i Christmas10.mp4 -i logo.png -filter_complex "[0:v][1:v]overlay=main_w-overlay_w-50:50[filtered]" -map "[filtered]" -map 0:a -codec:a copy paper.mp4
cut start at 1m until 20 seg
ffmpeg -t 1:00 -i paper.mp4 -ss 20 output.mp4
