Retrieve bitrate info from MPD

[Tim Curtis]

its a field named bitrate returned by the MPD status command.

pi@rp3:~ $ telnet localhost 6600
Trying ::1...
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
OK MPD 0.20.0
status
volume: 18
repeat: 0
random: 0
single: 0
consume: 0
playlist: 86
playlistlength: 87
mixrampdb: 0.000000
state: play
song: 47
songid: 48
time: 125:272
elapsed: 125.039
bitrate: 482
duration: 272.066
audio: 44100:16:2
nextsong: 48
nextsongid: 49
OK