Extract all subtitles from a movie using ffprobe & ffmpeg

.bashrc

alias subs=subs

function subs() {
    movie="${1}"
    filename="${1%.*}"
    mappings=`ffprobe -loglevel error -select_streams s -show_entries stream=index:stream_tags=language -of csv=p=0 "${movie}"`
    OLDIFS=$IFS
    IFS=,
    ( while read idx lang
    do
        echo "Exctracting ${lang} subtitle #${idx} from ${movie}"
        ffmpeg -nostdin -hide_banner -loglevel quiet -i "${movie}" -map 0:"$idx" "${filename}_${lang}_${idx}.srt"
    done <<< "${mappings}" )
    IFS=$OLDIFS
}

The issue im having is this producing 0kb sub files.

#!/usr/bin/env bash

function subs() {
  local movie idx lang subs=
  local -a dests=()
  for movie
  do
    ffprobe -loglevel error -select_streams s -show_entries stream=index:stream_tags=language -of csv=p=0 "$movie" |
    {
      while IFS=, read idx lang
      do
        subs+=" ${lang}_$idx"
        dests+=(-map "0:$idx" "${movie%.*}_${lang}_$idx.srt")
      done
      if test -n "$subs"
      then
        echo "Extracting subtitles from $movie:$subs"
        ffmpeg -nostdin -y -hide_banner -loglevel quiet -i "$movie" "${dests[@]}"
      else
        echo "No subtitles in $movie"
      fi
    }
  done
}

subs "${1}"