Document typical ffmpeg commands I use

ffmpeg.md

Extract only video from file

ffmpeg -i input.mov -c:v copy -an input_video.mov

Extract only audio from file

ffmpeg -i input.mov -c:a copy -vn input_audio.aac

Combine video and audio file

ffmpeg -i video.mov -i audio.aac -c:v copy -c:a copy video_new.mov

Rotate via https://gist.github.com/ViktorNova/1dd68a2ec99781fd9adca49507c73ee2

ffmpeg -i input.mov -metadata:s:v rotate="-90" -codec copy output.mov

Make GIF via https://superuser.com/a/556031

ffmpeg -ss 30 -t 3 -i input.mp4 -vf "fps=10,scale=320:-1:flags=lanczos,split[s0][s1];[s0]palettegen[p];[s1][p]paletteuse" -loop 0 output.gif
ffmpeg -i video.mov -vf "fps=6" -loop 0 output.gif
ffmpeg -i video.mov -vf "fps=6,scale=WIDTH:-1" -loop 0 output.gif
ffmpeg -i video.mov -vf "fps=6,scale=-1:HEIGHT" -loop 0 output.gif

• ss: number of seconds to skip from start
• t: number of seconds to convert
• fps frame rate
• scale convert video to resolution WIDTH:HEIGHT. Use -1 for auto -loop: number of times to loop. 0 = infinite looping.

Concatenate / Combine several files into one

https://trac.ffmpeg.org/wiki/Concatenate

ffmpeg -f concat -safe 0 -i mylist.txt -c copy output.wav

• The -safe 0 above is not required if the paths are relative.
• mylist.txt a list of all files to concatenated in the following form (lines starting with a # are ignored):

# this is a comment
file '/path/to/file1.wav'
file '/path/to/file2.wav'
file '/path/to/file3.wav'

Automatically generating the input file

*nix / macOS

# with a bash for loop
for f in ./*.wav; do echo "file '$f'" >> mylist.txt; done
# or with printf
printf "file '%s'\n" ./*.wav > mylist.txt

Windows

Command-line

(for %i in (*.wav) do @echo file '%i') > mylist.txt

Powershell

foreach ($i in Get-ChildItem .\*.wav) {echo "file '$i'" >> mylist.txt}

bat-file

(for %%i in (*.wav) do @echo file '%%i') > mylist.txt