Donald Feury

Posted on Apr 24, 2020 • Updated on Jun 27, 2021 • Originally published at donaldfeury.xyz

Add Fade In and Fade Out Effects With ffmpeg!

#ffmpeg #productivity #linux #video

I figured out that you don't need to use a full fledge video editor to apply some basic transition effects to video and audio.

Using ffmpeg, you can apply basic fade in and fade out to video using the fade filter. For audio, the afade filter can be used to achieve a similar effect.

ffmpeg -i video.mp4 -vf "fade=t=in:st=0:d=3" -c:a copy out.mp4

This will start the video with a black screen and fade in to full view over 3 seconds.

ffmpeg -i video.mp4 -vf "fade=t=out:st=10:d=5" -c:a copy out.mp4

This will make the video start fading to black over 5 seconds at the 10 second mark.

ffmpeg -i music.mp3 -af "afade=t=in:st=0:d=5" out.mp3

The audio file will start at a low volume and fade in to full over 5 seconds.

ffmpeg -i music.mp3 -af "afade=t=out:st=5:d=5" out.mp3

The audio file will start fading to zero volume over 5 seconds starting at the 5 second mark.

ffmpeg -i video.mp4 -vf "fade=t=in:st=0:d=10,fade=t=out:st=10:d=5" -c:a copy out.mp4

You can apply both fade in and out effects at the same time, to avoid having to re-encode twice.

Enjoy

Top comments (10)

pepa65 • Jun 23 '20

Can you also combine the video & audio fade at the same time?

Donald Feury • Jun 24 '20 • Edited

Sure, just use the afade filter in your filtergraph with the same start and end times as your fade filters.

Check out the documentation for the afade filter if you get confused - ffmpeg.org/ffmpeg-filters.html#afa...

pepa65 • Jun 25 '20

Got it, thanks! I made this bash function to make things easier for myself:

clipvid(){ # $1:source $2:start(ti:me) $3:fadein(s) $4:end(ti:me) $5:fadeout(s)
  usage="Usage: clipvid <sourcevideo> <start(time)> <fadein(s)>"
  usage+=" <end(time)> <fadeout(s)>"
  [[ -z $1 || $1 = -h || $1 = --help ]] &&
    echo $usage && return 0
  [[ ! -f $1 ]] &&
    echo -e "$usage\nSource video not a file: '$1'" && return 1
  [[ ! $2 = [0-9][0-9]:[0-5][0-9]:[0-5][0-9] ]] &&
    echo -e "$usage\nStarttime '$2' not in time format hh:mm:ss" && return 2
  [[ -z $3 || ${3//[0-9]} ]] &&
    echo -e "$usage\nFade-in seconds '$3' not numerical" && return 3
  [[ ! $4 = [0-9][0-9]:[0-5][0-9]:[0-5][0-9] ]] &&
    echo -e "$usage\nEndtime '$4' not in time format hh:mm:ss" && return 4
  [[ -z $5 || ${5//[0-9]} ]] &&
    echo -e "$usage\nFade-out seconds '$5' not numerical" && return 5
  tmp=$(mktemp).mp4
  local -i len=$(date -d $4 +%s)-$(date -d $2 +%s) ce=len-$5
  ffmpeg -i "$1" -ss "$2" -to "$4" -async 1 $tmp
  ffmpeg -i $tmp -vf "fade=t=in:st=0:d=$3,fade=t=out:st=$ce:d=$5" \
    -af "afade=t=in:st=0:d=$3,afade=t=out:st=$ce:d=$5" "$1.mp4"
  rm $tmp
}

Donald Feury • Jun 25 '20

Very nice! Your bash-fu is much stronger than mine 😉

Asbjørn Ulsberg • Dec 20 '22 • Edited

Great script, thanks for sharing @pepa65! I took the liberty to expand on it a bit and created the following Bash script which will only fade in from the start and out from the end, the amount of seconds specified in the --fade-in and --fade-out arguments, respectively.

joedotnot • Aug 30 '23

It appears the s=0 in video fade-in filter is redundant? you are starting from the beginning anyway.
-vf "fade=t=in:st=0:d=3"
is the same as
-vf "fade=t=in:d=3"