detect the fat of your pdf

fat.zsh

count_fat () awk -vmd5=1 -vfile=2 '
  { ++used[$md5] ; name[$md5]=$file }
  END {
    # is fat only if used more than 1 time
    for (n in name)
      if (--used[n])
        print name[n],used[n]
  }
'

total_fat () awk -vtimes=2 -vsize=3 '
  { sum += $times * $size }
  END { print sum }
'

md5sum videos/*         |
  count_fat             |
  tee fat               |
  awk '{print $1}'      |
  xargs stat -c '%n %s' > sizes

{ join fat sizes | total_fat
  stat -c%s *.pdf
  print '10k/100*p'
} |dc