ClashLuke

probe () {
  ffprobe -v error -show_entries $1 -of default=noprint_wrappers=1:nokey=1 $2
}

get_bitrate (){
  original=$1
  filesize=$2
  max_audio_bitrate=${3:-64000}
  seconds=`probe format=duration $original`
  total_bitrate=`echo "scale=0; (8 * $filesize/$seconds)" | bc`  # filesize in byte, bitrate in bit

ClashLuke

probe () {
  ffprobe -v error -show_entries $1 -of default=noprint_wrappers=1:nokey=1 $2
}

get_bitrate (){
  original=$1
  filesize=$2
  max_audio_bitrate=${3:-64000}
  seconds=`probe format=duration $original`
  total_bitrate=`echo "scale=0; (8 * $filesize/$seconds)" | bc`  # filesize in byte, bitrate in bit