[CentOS] VLC and playing .mkv files with opus audio

Hi list,
I use VLC from nux-dextop as my default player.
Recently began using youtube-dl and it grabs the video and audio just 
fine and produces  .mkv files.
I can play the resulting file just fine with Enqueue in SMPlayer, GXine, 
SMPlayer and Videos -
VLC unfortunately says 'VLC could not decode the format "Opus"'
Yet my google search indicates this issue was solved many releases ago - 
2.0.4 and CentOS 7 is at version 2.2.2-4.el7

Anyone else have this problem and/or ideas on how to get it going?
TIA
Rob