十年磨一剑

ffmpeg -i 84.avi -filter:v "crop=1000:400:0:300" 84_crop.avi

ffmpeg -i 84.avi -i 100.avi -filter_complex "hstack,format=yuv420p" -c:v libx264 -crf 18 -preset veryfast h.mp4 ffmpeg -i 84.avi -i 100.avi -filter_complex "vstack,format=yuv420p" -c:v libx264 -crf 18 -preset veryfast v.mp4

ffmpeg -loop 1 -i 4.png -c:v libx264 -t 10 2.mp4

ffmpeg -y -start_number 4 -i %d.png -filter:v “setpts=10*PTS” 1.avi

ffmpeg -i “concat:1.avi|2.avi|3.avi” -codec copy 123.avi

extract_command = 'ffmpeg -i ' + merged_4_video_name + ' -start_number 0 ' + merged_fold + '/%08d.png'