Discussion on: Add Fade In and Fade Out Effects With ffmpeg!

[pepa65]

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]

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

[Asbjørn Ulsberg]

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.