on2_p2_add_replaygain.liq

# This function takes a metadata,
# check if it is of type "file"
# and add the replay_gain metadata in
# this case
def add_replaygain(m) = 
  # Get the type
  type = m["type"]
  # The replaygain script is located there
  script = "#{configure.libdir}/extract-replaygain"
  # The file name is contained in this value
  filename = m["filename"]

  # If type = "song", proceed:
  if type == "song" then
    info = list.hd(get_process_lines("#{script} #{filename}")) 
    [("replay_gain",info)]
  # Otherwise add nothing
  else
    []
  end
end