Cheat sheet
Change format and bitrate of an audio file
ffmpeg -i ~/in.m4a -ab 128k out.mp3
Add a background to a transparent PNG, add an audio file and put all of them in a video.
ffmpeg -i background.png -stream_loop 50 -i animation.png -filter_complex overlay -i voiceover.m4a -c:v libx264 -c:a copy out.mp4
Scale video or image by keeping the aspect ratio and choosing the width.
ffmpeg -i ~/desktop/in.mov -vf scale=720:-1 ~/desktop/out.mp4
# multiple files at a time
for img in ~/desktop/pics/*.jpg; do ffmpeg -i '$img' -vf scale=1600:-1 '$img'; done;
both scaling and cropping a video
ffmpeg -i ~/desktop/in.mov -vf 'scale=720:-1,crop=720:720:0:300' ~/desktop/out.mp4
improve encoding of a video using H.265
ffmpeg -i ~/desktop/in4k.mp4 -c:v libx265 -vf scale=1080:-1 ~/desktop/out1080x265.mov
Creating an animated GIF from images
ffmpeg -framerate 4 -pattern_type glob -i '*.png' quotes.gif
Flags
-y # overwrite output flags