mpdnext

   1 #!/bin/bash
   2 # mpdnext
   3 #
   4 # This program runs as a daemon and manages the current mpd playlist
   5 # by changing the next song in the playlist to another similar song.
   6 #
   7 # To use this, select one song in your playlist and run this script.
   8 #
   9 # This script works best if your music is systematically ordered like this:
  10 # GENRE/ARTIST/ALBUM/SONG
  11 # for example:
  12 # Reggae/Bob Marley/1984 - Legend/09 - I Shot The Sheriff.ogg
  13 #
  14 # Change the depth by typing:
  15 # mpdnext <depth>
  16 #
  17 # The depth is a number that specifies how similar the next song will be.
  18 # A depth of 2 means, pick a random song from "Reggae/Bob Marley". A depth
  19 # of 0 would pick any random song.
  20
  21 # configuration
  22 short_interval=0.1
  23 long_interval=3
  24 configfile="$HOME/.mpdnextdepth"
  25
  26 # argument handling
  27 if [ "$1" == "--help" ]; then
  28         echo "Usage: mpdnext [OPTION] [new depth]"
  29         echo "Options:"
  30         echo "--help       print this text and exit"
  31         echo "--depth      print current depth and exit"
  32         echo "no argument  run in a loop"
  33         exit
  34 elif [ "$1" == "--depth" ]; then
  35         cat "$configfile"
  36         exit
  37 elif [ "$1" ]; then
  38         echo "$1" > "$configfile"
  39         exit
  40 fi
  41
  42 # preparations
  43 interval="$long_interval"
  44 previous_depth=`cat "$configfile"`
  45 counter=
  46 last=
  47 test -f "$configfile" || echo 1 > "$configfile"
  48 mpc crop
  49 mpc consume on
  50 mpc random off
  51
  52 # main loop
  53 while true; do
  54         mpc idle playlist > /dev/null
  55
  56         # get the depth
  57         depth=`cat "$configfile"`
  58         case "$depth" in
  59                 any)    depth=0;;
  60                 genre)  depth=1;;
  61                 artist) depth=2;;
  62                 album)  depth=3;;
  63                 stop)   continue;;
  64         esac
  65
  66         # delete the second song if the depth has changed
  67         if [ "$previous_depth" -a "$depth" != "$previous_depth" ]; then
  68                 echo depth changed to $depth
  69                 mpc del 2
  70                 previous_depth="$depth"
  71         fi
  72
  73         # don't care if playlist is longer than 2
  74         [ "`mpc playlist | head -2 | wc -l`" -gt 1 ] && continue
  75
  76         # keep the last "current song" in a buffer in case the playlist
  77         # is cleared.
  78         current="`mpc playlist -f '%file%' | head -1`"
  79         if [ "$current" ]; then
  80                 last="$current"
  81         else
  82                 current="$last"
  83         fi
  84
  85         # extract the path with the given depth
  86         cmd='s/^\/\?\(\([^\/]*\/\?\)\{0,'"$depth"'\}\)[\/$].*$/\1/'
  87         path=$(echo /"$current" | sed "$cmd")
  88
  89         # add one random song from that path
  90         mpc listall "$path" | shuf -n 1 | mpc add
  91         counter=50
  92         interval="$short_interval"
  93 done