variable speed playback

I’m about to buy rasp 2 with I2s dac , but I really need to know if I can with mdp (volumio) set the playback speed as it can be done with mplayer or vlc (from x0.25 to x4).
the reason is I need to use this for transcription of my lectures : sometimes I need to replay the whole lesson fast , but sometimes I need to play it slowly so I can write it on the computer.
now if the volumio UI doesnt have a knob for speed that’s ok (although that would be a good feature if it’s not yet implemented) , as I want to make a real physical knob connected to GPIO to control it. So in a word does mpd handle playing faster or slower , on the fly ( no changing bitrate conf, restarting etc) , like vlc player does ?

Thank you.

(Of course i2s conf for playing low res voice audio file is way too much but I want an All in one audio box project to fit all my needs and cant afford multiple devices).

alright as no one reply, I guess it means Volumio doent handle at all variable speed play back audio , even on command line level… good to know. I’ll try to use something else then.