# cropping/resizing 5MP GoPro to 720
for x in *.JPG; do convert $x -crop 2592x1458+0+243 -resize 1280 $x.jpg; done

# assembling time-lapse from GoPro
ffmpeg -r 30 -i '%*.JPG' -s 1280x720 -q:v 2 timelapse.mp4

# adding Audacity narrative/audio to GNOME screencast/webm
ffmpeg -i video.webm -i audio.wav -map 0:0 -map 1:0 -ar 48000 output.webm

# create video clip from image
ffmpeg -loop 1 -i img.png -c:v libx264 -t 30 -pix_fmt yuv420p -r 30 out.mp4

# 8x fast motion
ffmpeg -i in.mp4 -filter:a "atempo=2.0,atempo=2.0,atempo=2.0" -filter:v "setpts=0.125*PTS" -strict -2 out.mp4

# convert 1080 60fps to 720 30fps
ffmpeg -i in.mp4 -s 1280x720 -r 30 -strict -2 out.mp4

# mix music into video
ffmpeg -i in.mp4 -i music.mp3 -codec:v copy -codec:a aac -b:a 256k -filter_complex 'amerge,pan=stereo:c0<c0+c2:c1<c1+c3' -shortest -ar 48000 -strict -2 output.mp4

# convert mp3 to wav for editing in audacity
ffmepg -i in.mp3 out.wav

# extract audio from video
ffmpeg -i in.mp4 out.wav

# blur part of a video
ffmpeg -i short.mp4 -filter_complex "[0:v]split=2[v0][v1]; [v0]crop=200:200:60:30,boxblur=10[fg]; [v1][fg]overlay=60:30[v]" -map "[v]" -map 0:a -c:v libx264 -c:a copy -movflags +faststart filtered.mp4

# overlay an image and specify an output video bitrate
ffmpeg -i input.mp4 -i image.png -filter_complex "[0:v][1:v] overlay=25:25:enable='between(t,0,20)'" -pix_fmt yuv420p -c:a copy -b:v 20000k output.mp4

# increase audio volume
ffmpeg -i talking.mp4 -vcodec copy -af volume=15dB -strict -2 talking-louder.mp4

# decrease audio volume
ffmpeg -i talking.mp4 -vcodec copy -af volume=-15dB -strict -2 talking-quieter.mp4

# convert audio in video to 48000Hz 128k stereo
ffmpeg -i IMG_0775.MOV -vcodec copy -ar 48000 -b:a 128k -ac 2 IMG_0775.MOV.mp4

# change metadata playback rotation to actual rotation
ffmpeg -noautorotate -i IMG_0778.MOV.mp4 -acodec copy -vf "vflip,hflip" IMG_0778-rotated.mp4